GB2267098A

GB2267098A - Lubricants with enhanced low temperature properties

Info

Publication number: GB2267098A
Application number: GB9310329A
Authority: GB
Inventors: Rolfe John Hartley; Sanjay Srinivasan
Original assignee: Afton Chemical Corp
Current assignee: Afton Chemical Corp
Priority date: 1992-05-22
Filing date: 1993-05-19
Publication date: 1993-11-24
Also published as: DE4317105A1; GB9310329D0; CA2095972A1

Abstract

Lubricants having a Brookfield viscosity at -40 DEG C equal to or below 20,000 cP (preferably 15,000 or less) are formed from blends composed of a major amount of mineral oil in the range of 75N to 200N; and minor amounts of poly- alpha -olefin oligomer (PAO) formed from at least one 1-alkene of 6 to 20 carbon atoms, eg 1-decene, and having a kinematic viscosity in the range of 2 to 7 cSt at 100 DEG C; and acrylic polymeric viscosity index improver. Synergistic low temperature viscometric properties are exhibited by typical compositions of this type.

Description

2267098 LUBRICANTS WITH ENHANCED LOW TEMPERATURE PROPERTIES Viscosity

index improvers (VI improvers) find extensive use in the lubricant industry especially in ATF and crankcase formulations. Design changes in automatic transmissions have resulted in new requirements for automatic transmission fluids.

For optimum performance, electronically controlled transmissions require fluids with better low temperature properties. Accordingly, with the advent of DEXRONO HE specifications in early 1991 and a possible introduction of DEXRON0 III specifications for ATFs at the end of 1992, there has been a need and a strong effort to develop automatic transmission fluids with excellent low temperature properties.

To satisfy the DEXRONO HE specifications, a Brookfield viscosity of 20, 000 cP or less at -40 0 C is required. For DEXRONO M specifications, the Brookfield viscosity may have to be 15,000 cP or less at -40 0 C.

In many cases, light base stocks (e.g., below 10ON) are being used to meet DEXRON11 RE requirements since these base stocks inherently contain less wax.

However, this results in increased VI improver treat rates to meet the required 0 C kinematic viscosity.

An important contribution to the art would be an effective way of enabling use of mineral oil base stocks in the range of 75N to 20ON in formulations having enhanced low temperature (e.g., -40 0 C) properties and reduced requirements for polymeric viscosity index improvers. This invention is believed to constitute such a contribution.

In one of its embodiments this invention provides an oleaginous composition which comprises:

a) a major amount of mineral oil in the range of 75N to 20ON (preferably in the range of 85N to 160N, and most preferably in the range of 90N to 140N, e. g., 1 10ON); and minor amounts of b) poly-a-olefin oligomer formed by a process comprising oligomerizing at least one 1-alkene having in the range of 6 to 20, preferably 8 to 16, more preferably 10 to 12 and most preferably 10, carbon atoms in the molecule, said oligomer having a Idnematic viscosity at 100 "C in the range of 2 to 7 cst, preferably in the range of 2 to 6 cSt, more preferably in the range of 2 to 4 eSt, and most preferably about 2 cSt, said oligomer preferably but not necessarily being a hydrogenated oligomer; and c) an oil-soluble acrylic polymeric viscosity index improver; the composition being further characterized by having a Brookfield viscosity at -40 0 C equal to or below 20,000 cP, and preferably equal to or below 15,000 cP.

Another embodiment is an oleaginous composition which comprises:

a) a major amount of mineral oil in the range of 75N to 20ON (preferably in the range of 85N to 160N, and most preferably in the range of 9ON to 140N, e. g., 10ON); and minor amounts of b) poly-a-olefin oligomer formed by a process comprising oligomerizing at least one 1-alkene having in the range of 6 to 20, preferably 8 to 16, more preferably 10 to 12 and most preferably 10, carbon atoms in the molecule, said oligomer having a Idnematic viscosity at 100 C in the range of 2 to 7 cSt, preferably in the range of 2 to 6 cSt, more preferably in the range of 2 to 4 cSt, and most preferably about 2 cSt, said oligomer preferably but not necessarily being a hydrogenated oligomer; and c) a solution of a poly(allylmethacrylate) polymeric viscosity index improver in a hydrocarbonaccous solvent wherein said solution has a bulk viscosity in the range of 600 to 1200 cSt at 100 Q the composition being further characterized by having a Brookfield viscosity at -40 0 C equal to or below 20,000 cP, and preferably equal to or below 15,000 cP.

Among the advantages made possible by this invention is the achievement of very good low temperature viscometric properties (e.g., at -40, C) in mineral oil base 1 2 stocks having better high temperature viscometric properties than mineral oils of lighter viscosity grades (i.e., below 10ON). Further, this invention enables preparation of lubricant and functional fluid compositions having greater shear stability and better thermal and oxidative properties as compared for example to ATFs formulated in lighter naphthenic base stocks.

Moreover, powerful synergistic behavior in low temperature viscometric properties can be -- indeed, have been -- achieved in at least some of the compositions of this invention. This in turn makes it possible to reduce the amount of the above components b) and/or c) while achieving the synergistic low temperature performance enhancement.

In one preferred embodiment, the polymeric viscosity index improver is a solution composed of 30 to 45 weight percent of acrylic-type viscosity index improver (e.g., poly(alkylmethacrylate) polymer) dissolved in 70 to 55 weight percent of a hydrocarbonaceous solvent, which solution has a bulk viscosity of 600 to 800 cSt at 100 0 C. One example of such a viscosity index improver is Acryloid', 1263 oil additive (Rohm & Haas Company) which is indicated by the manufacturer to have a nominal bulk viscosity of 700 cSt at 100 0 C and a typical basic nitrogen content of 0.12%. As to composition, the manufacturer indicates as of June 1990 that the product is comprised of 40-42 wt % acrylic copolymer, 1.9 wt % maximum of residual monomer(s), and 58-60 wt % of naphthenic hydrocarbons (CAS Reg. Nos. 64742-53-6 and 64741-97-5 being listed). Earlier versions of the product were identified as having 34-39 wt % acrylic copolymer and 61-66 wt % of extracted naphthenic oil and solvent-refined light naphthenic distillates. Also useful are AcryloidO 1265 and Acry loidO 1267 VI improvers. These are indicated to have bulk viscosities of 700 cSt at 100C. Their contents of basic nitrogen are specified, respectively, as 0. 14 and 0.16 In another preferred embodiment the polymeric viscosity index improver is a solution composed of 20 to 65 weight percent of acrylic-type viscosity index improver 3 (e.g., poly(alkylmethacrylate) copolymer) dissolved in 35 to 80 weight percent of a hydrocarbonaceous solvent, which solution has a bulk viscosity of 800 to 1200 cSt at "C. One example of such a viscosity index improver is Texacoc TLA-5010 oil additive (Texaco Chemical Company) which is indicated by the manufacturer to have a nominal bulk viscosity of 1000 cSt at 100 C, a typical specific gravity of 0.905, and to be comprised of 4.00-10.99% polymerized methacrylic acid, n-butyl ester; 1.00 3.99% polymerized dimethylaminopropylmethacrylamide; and 20.00-34.99% polymerized methacrylic acid "lauryl" ester; dissolved in 35.00-49.99% of severely solvent-refined hydrotreated light naphthenic petroleum distillates and 11.00-19.99% of severely refined hydrotreated heavy naphthenic petroleum distillates. Presumably the percentages for the components of the TLA-5010 are weight percentages.

In yet another preferred embodiment of this invention, the acrylic-type viscosity index improver is a solution of polymethacrylate viscosity index improver in a severely refined mineral oil wherein the mineral oil content is in the range of 40 to 45 wt %, and wherein the solution has a bulk viscosity in the range of 600 to 800 cSt at 100 C. ViscoplexO 0-800 viscosity index improver (Rohm Tech Inc.) is an example of such a viscosity index improver. According to the manufacturer, this product has a mineral oil content of approximately 42%, a specific gravity at 15 0 C of 0.9 g/mI, a flash point of over 200 C (ASTM D 92), and a bulk viscosity of 700 cSt at 100 C.

In the preferred embodiments described above it is especially preferred to utilize a hydrogenated poly-a-olefin oligomer having a kinematic viscosity in the range of 2 to 4 cSt at 100 0 C, and most preferably about 2 cSt at 100 o C.

Other embodiments and features of this invention will become still further apparent from the ensuing description and appended claims.

4 Component a The mineral oil base stock used in the compositions of this invention falls in the specification category of 75N to 20ON, and can be a single mineral oil or a blend of two or more mineral oils. Naphthenic base oils can be used, and these are pre- ferably highly refined oils such as solvent-treated neutral oils. Preferred base stocks for use in this invention are paraffinic oils, such as solvent refined paraffinic: base stocks, hydrotreated paraffinic: base stocks, and hydrotreated and catalytically dewaxed paraffinic: base stocks. Some aromatic oils may be suitable, though are less preferred. Blends, preferably those containing a major amount of paraffinic base stock are also suitable.

The mineral oils can be refined from crude oil of any source including Gulf Coast, Midcontinent, Pennsylvania, California, Alaska, Middle East and North Sea. Standard refinery operations may be used in processing the mineral oil.

A considerable number of suitable mineral oils are available from various petroleum refiners.

Co=onent-h) As noted above, the oleaginous compositions of this invention comprise a minor amount (i.e., less than 50 percent by weight) of at least one poly- a-olefin oligomer fluid having a kinematic viscosity at 100 0 C in the range of 2 to 7 cSt, preferably in the range of 2 to 6 cSt, more preferably in the range of 2 to 4 cSt, and most preferably about 2 cSt. Such fluids are formed by oligomerization of at least one 1-alkene hydrocarbon having in the range of 6 to 20, preferably 8 to 16, more preferably 10 to 12 and most preferably 10, carbon atoms in the molecule. The oligomerization is usually performed catalytically. 7he oligomer fluid can be a hydrogenated oligomer fluid or an unhydrogenated oligomer fluid. Hydrogenated oligomers are preferred, and hydrogenated oligomers formed from 1-decene are particularly preferred.

Methods for the production of such Hquid oligomeric 1-alkene hydrocarbons are known and reported in the literature. See for example U.S. Pat. Nos. 3,763,244; 3,780,128; 4,172,855; 4,218,330; and 4,950,822. Additionally, hydrogenated 1-alkene oligomers of this type are available as articles of commerce, for example, under the trade designations ETHYULX) 162, ETHYLEL0 164 and ETHYLFLO 166 polywa-olefin oils (Ethyl Corporation; Ethyl Canada Limited; Ethyl SA). Tabulated below are data concerning typical composition and properties of these products. In these tabulations the typical compositions are expressed in terms of normalized area percentages by CC, and "n.d." means "not determined".

ETTlYUL0 162 12o-ly--a-olefin- oil:

Co=osition - Monomer 0.4, Dimer 90.7, Trimer 8.3, Tetramer 0.6.

PrUerties - Viscosity at 100 C: 1.80 cSt; Viscosity at 40 0 C: 5.54 cSt; Viscosity at -18 o Q n.d.; Viscosity at -40 0 C: 306 cSt; Pour point: -63 0 C; Flash point (ASTM D 92): 165 C; NOACK volatility: 99%.

ETHYLFLO 164 po-ly--a-olefin oil Composition - Trimer 82.7, Tetramer 14.6, Pentamer 2.7.

Properties - Viscosity at 100 0 C: 4.06 cSt; Viscosity at 40 o C: 17.4 cSt; Viscosity at -18 C: n.d.; Viscosity at -40 C: 2490 cSt; Pour point: < -65 Q Flash point (ASTM D 92): 224 0 C; NOACK volatility: 12.9%.

ETHYLFLO 166 12o!31-a-olefin oil:

Composition - Trimer 32.0, Tetramer 43.4, Pentamer 21.6, Hexamer 3.0.

Properties - Viscosity at 100 0 C: 5.91 cSt; Viscosity at 40 0 Q 31.4 cSt; Viscosity at -18 0 C: n.d.; Viscosity at -40 0 C: 7877 cSt; Pour point: -63 C; Flash point (ASTM D 92): 235'C; NOACK volatility: 7.5%.

Suitable 1-alkene oligomers are also available from other suppliers. As is well known, hydrogenated oligomers of this type contain little, if any, residual ethylenic unsaturation, whereas unhydrogenated oligomers contain some residual unsaturation.

Preferred oligomers are formed by use of a Friedel-Crafts catalyst (especially boron trifluoride promoted with water or a Cl-20 alkanol) followed by catalytic hydrogenation of the oligomer so formed using procedures such as are described in 6 the foregoing U.S. patents.

Other catalyst systems which can be used to form oligomers of 1-alkene hydrocarbons, which, on hydrogenation, provide suitable oleaginous liquids include Zlegler catalysts such as ethyl aluminum sesquichloride with titanium tetrachloride, aluminum. alkyl catalysts, chromium oxide catalysts on silica or alumina supports and a system in which a boron trifluoride catalyst oligomerization is followed by treatment with an organic peroxide.

Natures or blends of 1-alkene oligomers can also be used in the practice of this invention provided the overall blend possesses the requisite viscosity characteristics as specified above. Typical examples of suitable blends of hydrogenated 1-decene oligomers include the following blends in which the typical compositions are expressed in terms of normalized area percentages by GC and wherein "n.d." means "not determined".

75.125 Blend of ETHYLFLO 162 and ETHYLFLO 164 paly-a-olefin oils:

Composition - Monomer 0.3, Dimer 66.8, Trimer 27.3, Tetramer 4.8, Pentamer 0.8.

Properties - Viscosity at 100 0 C: 2.19 cSt; Viscosity at 40 C: 7.05 cSt; Viscosity at -18'C: 84.4 cSt; Viscosity at -40 0 C: 464 cSt; Pour point: < -65 0 C; Flash point (ASTM D 92): 166 0 C; NOACK volatility: 78.2%.

5Q/50 Blend of ETHYLFLO 162 and ETHYLFLO 164 12oly-a-olefin oils:

Composition - Monomer 0.2, Dimer 44.7, Trimer 45.9, Tetramer 7.6, Pentamer 1.3, Hexamer 0.3.

Properties - Viscosity at 100 C: 2.59 cSt; Viscosity at 40 C: 9.36 cSt; Viscosity at -18 1, C: 133 cSt; Viscosity at -40 C: 792 cSt; Pour point: < -65 0 C; Flash point (ASTM D 92): 168'C; NOACK volatility: 57.4%.

25./75 Blend of ETHYLFLO 162 and ETHYLFLO 164 poly-a-olefin oils:

Composition - Monomer 0.1, Dimer 23.1, Trimer 62.7, Tetramer 11.5. Pentamer 2.1, Hexamer 0.5.

7 RIQpertie - Viscosity at 100 0 C: 3.23 cSt; Viscosity at 40 0 C: 12.6 cSt; Viscosity at -18 c C: 214 cSt; Viscosity at -40 0 C: 1410 cSt; Pour point: < -65 a C; Flash point (ASTM D 92): 190 C; NOACK volatility: 30.8%.

95/05 Blend of ETHYLFLO 164 and WHYM0 166 poly-"lefin oils:

Co=osition - Dimer 0.5, Trimer 78.4, Tetramer 15.6, Pentamer 3.7. Hexamer 1.8.

Properties - Viscosity at 100 0 C.. 4.15 cSt; Viscosity at 40 0 C: 17.9 cSt; Viscosity at -18 0 C: n.d.; Viscosity at -40 0 C: 2760 cSt; Pour point: < -65 9 C; Flash point (ASTM D 92): 225 0 C; NOACK volatility: 10.5%.

90.110 Blend of ETHYLFLO 164 and ETHYLFLO 16612o!y--a-olefin oils:

Composition - Dimer 0.3, Trimer 76.0, Tetramer 17.0, Pentamer 4.7, Hexamer 2.0.

Properties - Viscosity at 100 " C: 4.23 cSt; Viscosity at 40 o C: 18.4 cSt; Viscosity at - 18 0 C: n.d.; Viscosity at -40 0 C: 2980 cSt; Pour point: < -65 0 C; Flash point (ASTM D 92): 228 0 C; NOACK volatility: 11.4%.

80120 Blend of ETHYLFLO 164 and ETHYLFLO 166 12olly-a-olefin oila Composition - Dimer 0.3, Trimer 71.5, Tetramer 19.4, Pentamer 6.5, Hexamer 2.3.

Properties - Viscosity at 100 C: 4.39 cSt; Viscosity at 40 0 C: 19.9 cSt; Viscosity at -18 0 C: n.d.; Viscosity at -40 0 C: 3240 cSt; Pour point: < -65 0 C; Flash point (ASTM D 92): 227 0 C; NOACK volatility: 9.2%.

75,125 Blend of ETHYLFLO 164 and ETHYLFLO 166 12oly-a-olefin oils Composition - Dimer 0.7, Trimer 69.0, Tetramer 21.0, Pentamer 7.3, Hexamer 2.0.

Properties - Viscosity at 100 0 C: 4.39 cSt; Viscosity at 40 C: 20.1 cSt; Viscosity at -18 C: 436 cSt; Viscosity at -40 0 C: 3380 eSt; Pour point: < -65 c C; Flash point (ASTM D 92): 226 o C; NOACK volatility: 14.2%.

50150 Blend of ETHYLFLO 164 and ETHYLFLO 166 12oly-a-olefin oils:

Composition - Dimer 0.4, Trimer 57.3, Tetramer 27.4, Pentamer 11.8, Hexamer 3.1.

Properties - Viscosity at 100 " C: 4.82 cSt; Viscosity at 40' C: 23.0 cSt; Viscosity 8 at -18 C: 544 cSt; Viscosity at -40 0 C: 4490 cSt; Pour point: < -65 0 C; Flash point (ASIM D 92): 226 0 C; NOACK volatility: 12.5%.

25/75 Blend of EIM:1M 164 and ETHYLFLO 16612olyza-olefin oils:

Composition - Dimer 0.3, Trimer 45.3, Tetramer 33.4, Pentamer 16.4, Hexamer 4.6.

Properties - Viscosity at 100 0 C: 5.38 cSt; Viscosity at 40 0 C: 26.8 cSt; Viscosity at -18 o C: 690 eSt; Viscosity at -40 0 C: 6020 eSt; Pour point: < -65 C; Flash point (ASTM D 92): 250 C; NOACK volatility: 9.2%.

75125 Blend of EI RYUL0 166 and ETHYLFLO 168 j2oly:a-olefin oils:

CoMosition - Dimer 0.4, Trimer 28.4, Tetramer 42.0, Pentamer 22.9, Hexamer 6.3.

Properties - Viscosity at 100 0 C: 6.21 eSt; Viscosity at 40 0 C: 33.7 cSt; Viscosity at -18 0 C: 1070 cSt; Viscosity at -40 0 C: 9570 cSt; Pour point: < -65 C; Flash point (ASTM D 92): 242 0 C; NOACK volatility: 6.8%.

50,150 Blend of EI RYULO 166 and ETHYLFLO 168 poly-a-olefin oils:

Composition - Trimer 20.4, Tetramer 45.4, Pentamer 26.5, Hexamer 7.7.

Properties - Viscosity at 100 0 C: 6.79 cSt; Viscosity at 40 0 C: 38.1 cSt; Viscosity at -18 0 C: 1180 cSt; Viscosity at -40 " C: 12200 cSt; Pour point: < -65 0 C; Flash point (ASTM D 92): 244 a C; NOACK volatility: 6.0%.

Component-c) Oil-soluble acrylic polymeric viscosity index improvers and methods for their preparation are well known to those skilled in the art. See for example W. L van Home, Ind. Eng. Chem. 41,952 (1949); F. J. Glavis, Ind. Eng. Chem. 42, 2441 (1950); and U.S. Pat. Nos. 2,091,627, 2,100,993, 2,114,233, 3,052,648, 3,163,605, 3,506,574, 4,036,766, 4,496,691, 4,606,834, 4,968,444, 5,013,468, and 5,013,470.

As is well known, the function of a viscosity index improver is to maintain the viscosity of an oil at a relatively constant viscosity over the range of operating temperatures. As reflected in some of the foregoing documents, acrylate or methacrylate ester polymers and copolymers serve this function very 'effectively.

9 Moreover, oil-soluble acrylic polymeric viscosity index improvers have been developed that contribute additional functions to the lubricant such as dispersancy, or antioxidancy.

A number of acrylic viscosity index improvers are available on the open market, a number of such products having been identified hereinabove.

The acrylic ester viscosity index improver is usually employed in the form of a solution or mixture in a suitable light mineral oil, e.g., 40N to 20ON hydrotreated paraffinic oil or 40N to 20ON highly refined naphthenic oil. If desired, however, the acrylic ester viscosity index improver can be used in the form of a solution in a poly a-olefin oil, such as a poly-a-olefin oil of the type used as component b) of the compositions of this invention. In such case a suitable light mineral oil may also be present or it may not be used as a diluent for the acrylic ester polymer. It will thus be seen that components b) and c) can be in combination with each other, with or without an ancillary light mineral oil diluent or solvent, before blending components b) and c) with component a).

Components a), b) and c) can be blended together concurrently or in any sequence and the mixture can be stirred or otherwise agitated to insure homogeneity.

Application of heat to the mixture during blending can prove useful in facilitating the blending operation. Of course the temperature should be kept well below the temperature at which thermal degradation of any component would occur. Thus during blending, temperatures are often held to a maximum of about 60 0 C, although higher temperatures are usually permissible.

Proportions of Components a), b) and c) As noted above, the poly-a-olefin oligomer and the acrylic ester polymeric viscosity index improver are used in amounts and proportions in the particular mineral oil being used as component a) such that the resultant composition has a Brookfield viscosity at -40'C of 20,000 cP or less and preferably of 15, 000 cP or less.

The particular amounts used are thus susceptible to considerable variation and will depend on the characteristics and properties of each of components a), b) and c) being used in any given case. Generally speaking, however, the composition will usually contain at least 1, preferably at least 3, more preferably at least 7, and most preferably at least 9 percent by weight of component b) -- i.e., the oligomer -- and at least 0.01, preferably at least 0.02, more preferably at least 0.04, still more preferably at least 2, and most preferably at least 3 percent by weight of component c) -- i.e., the polymeric VI improver. For best results, the amount of component b) used should be at least sufficient not only to achieve the low temperature viscometrics described above (i.e., 20,000 cP or less at -40 0 C) but to provide a finished composition having a kinematic viscosity of at least 6.5 cSt at 100 Q and preferably at least 6.8 cSt at 100 0 C. In any case, the total amount of components b) and c) will be less than 50% by weight of the total composition. It should be noted that the foregoing weight percentages for the component c) polymeric VI improver refer to the weight of the actual polymer and not the weight of a solution or mixture of the polymer in a diluent or solvent, the latter being the form in which the VI improver is most often employed. In short, the concentrations of component c) as set forth herein refer to the weight of active polymeric VI improver and exclude the weight of any solvents or diluents associated therewith.

As will be apparent from the data set forth hereinafter, a particularly preferred aspect of this invention is to employ components b) and c) in proportions and amounts such that a synergistic improvement in Brookfield viscosity at -40 0 C is achieved.

Other Components and Additives A. Other Oils. If desired, the compositions of this invention can contain minor amounts (preferably no more than 30 wt %) of other suitable oleaginous base stocks for imparting additional properties required and/or desired for the particular end use for which the finished lubricant or functional fluid is intended. The chief requirements are that (1) any such additional base stock should not adversely affect 11 the low temperature viscosity performance to the extent that the resultant composition fails to possess a Brookfield viscosity at -40 11 C of 20,000 cP or less, and preferably of 15,000 cP or less; and (2) any such additional base stock should exhibit suitable compatibility with the other components of the composition so as not to significantly impair its stability, homogeneity, or performance capabilities.

Aklene oxide polymers and interpolymers and derivatives thereof where the terminal hydroxyl groups have been modified e.g., by esterification, or etherification constitute one class of synthetic oils that can be considered for use in the compositions of this invention. 7Iese are exemplified by the oils prepared through polymerization of alkylene oxides such as ethylene oxide or propylene oxide, and the alkyl and aryl ethers of these polyoxyalkylene polymers (e. g., methyl polyisopropylene glycol ether having an average molecular weight of 1000, diphenyl ether of polyethylene glycol having a molecular weight of 500-1000, diethyl ether of polypropylene glycol having a molecular weight of 1000-1500) or monoand poly- carboxylic esters thereot for example, the acetic acid ester, mixed C3-C6 fatty acid esters, or the C13 Oxo acid diester of tetraethylene glycol.

Another class of synthetic oils that may be considered for use comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer) with a variety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2- ethylhexyl alcohol, ethylene glycol). Specific examples of these esters include dibutyl adipate, di(2ethylhexyl)adipate, didodecyl adipate, di- (isotridecyl)-adipate (e.g., BASF Glissofluid A13), di(2- ethylhexyl)sebacate, dilauryl sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, niixed C9 and C,, dialkylphthalates (e.g., ICI Emkarate 911P ester oil), di(eicosyl)sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid.

12 Synthetic esters which may be used also include those made from (3-C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol and dipentaerythritol. Trimethylol propane tripelargonate, trimethylol propane trioleate, pentaerythritol tetraheptanoate and pentaerythritol tetracaproate serve as examples.

Silicon-based oils such as the polyalkyl-, polyaryl-, polyalko)e, or polyaryloXY siloxane oils and silicate oils comprise another class of synthetic lubricants that may be selected for use. llese include, for example, tetraethyl silicate, tetraisopropyl silicate, tetra(2-ethylhexyl) silicate, tetra- (p -tert-butylphenyl) silicate, poly(methyl)siloxanes, and poly(methylphenyl)siloxanes. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids, e.g., tricresyl phosphate, trioctyl phosphate, triphenyl phosphite, and diethyl ester of decane phosphonic acid.

Among additional oils which may be considered for use in suitable amounts in the compositions of this invention are homo- and interpolymers of C2C12 olefins, polyglycols, alkylated aromatics, carbonates, thiocarbonates, orthoformates, borates and halogenated hydrocarbons. Representative of such oils are homo- and interpolymers of CTC12 monoolefinic hydrocarbons, alkylated benzenes (e.g. , dodecyl benzenes, didodecyl benzenes, tetradecyl benzenes, dinonyl benzenes, and di-(2 ethylhexyl)benzenes.

Illustrative additional oils of lubricating viscosity which may be used in the blends of this invention include liquid natural fatty oils and esters such as castor oil, olive oil, peanut oil, rapeseed oil, corn oil, sesame oil, cottonseed oil, soybean oil, sunflower oil, safflower oil, hemp oil, linseed oil, tung oil, oiticica oil, jojoba oil, and meadowfoarn oil. Such oils may be partially or fully hydrogenated, if desired, provided of course that they retain their oleaginous character.

B. Additives. The additives that can be, and preferably are, included in the 13 compositions of this invention can vary widely depending on such factors as the use or service for which the finished composition is intended, the severity of the service conditions to which the composition is likely to be exposed, the properties the particular composition is to possess, and the specifications the particular composition is to satisfy. Thus the oil may be formulated with-additives or additive concentrates appropriate for service as crankcase lubricants for spark ignition or diesel internal combustion engines, as lubricants for use as cylinder oils, as functional fluids for use as automatic transmission fluids, and as oils for use as manual transmission lubricants, wet brake fluids, tractor oils, gear oils, and limited slip axle lubricants.

Those skilled in the art are familiar with the general maketip of additive packages commonly used for these various types of service. Anyone not familiar with the technology need only refer to the tremendous amount of patent literature on the subject, especially U. S. Patents issued during the last ten years. For a review of crankcase lubricating oil additives, reference may be had to Watson, R. L and McDonnell, Jr., "Additives - The Right Stuff for Automotive Engine OUC Society of Automotive Engineers Special Publication SP-603 (Fuels and Lubrication Technology), pages 17-28 (1984) and references cited therein. Particularly preferred crankcase lubricating oil additive compositions are described in Examples I through XVffi of U.S. Pat. No. 4,904,401 and particularly preferred automatic transmission additive compositions are described in U.S. Pat. No. 4,857,214.

Described below are illustrative examples of some of the types of conventional additives that may be employed in conventional amounts in the compositions of this invention.

Any of a variety of ashless dispersants can be utilized in the compositions of this invention. These include the following types:

lype A - Carboicylic Ashless Dispersants. These are reaction products of an acylating agent (e.g., a monocarboxylic acid, dicarboxylic acid,polycarboxylic acid, or 14 derivatives thereof) with one or more polyamines and/or polyhydroxy compounds.

These products, herein referred to as carboxylic ashless dispersants, are described in many patents, including British Patent Specification 1,306,529 and the following U.

S. Patents: 3,163,603; 3,184,474; 3,215,707; 3,219,666; 3,271,310; 3,272, 746; 3,281,357; 3,306,908; 3,311,558; 3,316,177; 3,340,281; 3,341,542; 3,346,493; 3,381, 022; 3,399,141; 3,415,750; 3,433,744; 3,444,170; 3,448,048; 3,448,049; 3,451,933; 3,454, 607; 3,467,668; 3,522,179; 3,541,012; 3,542,678; 3,574,101; 3,576,743; 3,630,904; 3,632, 510; 3,632,511; 3,697,428; 3,725,441; 3,868,330; 3,948,800; 4,234,435; and Re 26,433.

There are a number of sub-categories of carboxylic ashless dispersants. One such sub-category which constitutes a preferred type is composed of the polyamine succinamides and more preferably the polyamine succinimides in which the succinic group contains a hydrocarbyl substituent containing at least 30 carbon atoms. The polyamine used in forming such compounds contains at least one primary amino group capable of forming an imide group on reaction with a hydrocarbon- substituted succinic acid or acid derivative thereof such an anhydride, lower alkyl ester, acid halide, or acid-ester. Representative examples of such dispersants are given in U.S. Pat. Nos. 3,172,892; 3,202,678; 3,216,936; 3,219,666; 3,254, 025; 3,272,746; and 4,234,435. The alkenyl succinimides may be formed by conventional methods such as by heating an alkenyl succinic anhydride, acid, acid-ester, acid halide, or lower alkyl ester with a polyamine containing at least one primary amino group. The alkenyl succinic anhydride may be made readily by heating a mixture of olefin and maleic anhydride to 180 0 -220 0 C. The olefin is preferably a polymer or copolymer of a lower monoolefin such as ethylene, propylene, 1-butene, or isobutene. The more preferred source of alkenyl group is from polyisobutene having a number average mo- lecular weight of up to 100,000 or higher. In a still more preferred embodiment the alkenyl group is a polyisobutenyl group having a number average molecular weight (determined using the method described in detail hereinafter) of 500- 5,000, and preferably 700-2,500, more preferably 700- 1,400, and especially 800-1,200. The isobutene used in making the polyisobutene is usually (but not necessarily) a mixture 30 of isobutene and other C4 isomers such as 1-butene. Thus, strictly speaking, the acylating agent formed from maleic anhydride and "polyisobuten&' made from such mixtures of isobutene and other C4 isomers such as 1-butene, can be termed a "polybutenyl succinic anhydride" and a succinimide made therewith can be termed a "polybutenyl succinimid&'. However, it is common to refer to such substances as "polyisobutenyl succinic anhydride!'and "polyisobutenyl succinimide", respectively. As used herein "polyisobutenyP'is used to denote the alkenyl moiety whether made from a highly pure isobutene or a more impure mixture of isobutene and other C4 isomers such as 1-butene.

Polyamines which may be employed in forming the ashless dispersant include any that have at least one primary amino group which can react to form an imide group. A few representative examples include branched-chain alkanes containing two or more primary amino groups such as tetraamino-neopentane; polyaminoalkanols such as 2-(2-aminoethylamino)-ethanol and 2-[2-(2-aminoethylamino)- ethylaminol- ethanol; heterocyclic compounds containing two or more amino groups at least one of which is a primary amino group. such -as. 1-(B-amineethyl)-2- imidazolidone; Z.(2 aminoethylamino)-5-nitropyridine, 3-amino-N-ethylpiperidine, 2-(2aminoethyl) pyridine, 5-aminoindole. 3-amino-5-mercapto-1,2,4-triazole, and 4- (aminomethyl) piperidine; and the alkylene polyamines such as propylene diamine, dipropylene triamine, di-(1,2-butylene)triamine, N-(2-aminoethyl)-1,3-propanediamine, hexamethylenediamine and tetra-(1,2-propylene)pentamine.

The most preferred amines are the ethylene polyamines which can be depicted by the formula H2N(CH2CH2NH),H wherein n is an integer from one to ten. These include: ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, and pentaethylene hexamine, including mixtures thereof in which case n is the average value of the mixture. These ethylene polyamines have a primary amine group at each end so can form mono-alkenylsuccinimides and bis-alkenylsuccinimides.

Commercially available ethylene polyamine mixtures usually contain minor amounts 16 of branched species and cyclic species such as N-aminoethyl piperazine, N,N'-bis(aminoethyl)piperazine, and N,N'-bis(piperazinyl)ethane. The preferred com mercial mixtures have approximate overall compositions falling in the range corresponding to diethylene triamine to pentaethylene hexamine, niixtures generally corresponding in overall maketip to tetraethylene pentamine being most preferred.

Methods for the production of polyalkylene polyamines are known and reported in the literature. See for example U.S. Pat. No. 4,827,037 and references cited therein.

Thus especially preferred ashless dispersants for use in the present invention are the products of reaction of a polyethylene polyamine, e.g., triethylene tetramine or tetraethylene pentamine, with a hydrocarbon-substituted carboxylic acid or anhydride (or other suitable acid derivative) made by reaction of a polyolefin, preferably polyisobutene, having a number average molecular weight of 500 to 5,000, preferably 700 to 2,500, more preferably 700 to 1,400 and especially 800 to 1,200, with an unsaturated polycarboxylic acid or anhydride, e.g., maleic anhydride, maleic acid, or fumaric acid, including mixtures of two or more such substances.

As used herein the term "succinimide" is meant to encompass the completed reaction product from reaction between the amine reactant(s) and the hydrocarbon substituted carboxylic acid or anhydride (or like acid derivative) reactant(s), and is intended to encompass compounds wherein the product may have an-dde, amidine, and/or salt linkages in addition to the imide linkage of the type that results from the reaction of a primary amino group and an anhydride moiety.

Residual unsaturation in the alkenyl group of the alkenyl succinimide may be used as a reaction site, if desired. For example the alkenyl substituent may be hydrogenated to form an alkyl substituent. Similarly the olefinic bond(s) in the alkenyl substituent may be sulfurized, halogenated, or hydrohalogenated. Ordinarily, there is little to be gained by use of such techniques, and thus the use of alkenyl succinimides is preferred.

17 Another sub-category of carboxylic ashless dispersants which can be used in the compositions of this invention includes alkenyl succinic acid esters and diesters of alcohols containing 1-20 carbon atoms and 1-6 hydroxyl groups. Representative examples are described in U.S. Pat. Nos. 3,331,776; 3,381,022; and 3,522, 179. The alkenyl succinic portion of these esters corresponds to the alkenyl succinic portion of the succinimides described above including the same preferred and most preferred subgenus, e.g., alkenyl succinic acids and anhydrides, where the alkenyl group contains at least 30 carbon atoms and notably, polyisobutenyl succinic acids and anhydrides wherein the polyisobutenyl group has a number average molecular weight of 500 to 5,000, preferably 700 to 2,500, more preferably 700 to 1,400, and especially 800 to 1,200. As in the case of the succinimides, the alkenyl group can be hydrogenated or subjected to other reactions involving olefinic double bonds.

Alcohols useful in preparing the esters include methanol, ethanol, 2 methylpropanol, octadecanol, eicosanol, ethylene glycol, diethylene glycol, tetraethylene glycol, diethylene glycol monoethylether, propylene glycol, tripropylene glycol, glycerol, sorbitol, 1,1,1-trimethylol ethane, 1,1,1-trimethylol propane, 1,1,1-trimethylol butane, pentaerythritol, and dipentaerythritol.

The succinic esters are readily made by merely heating a mixture of alkenyl succinic acid, anhydrides or lower alkyl (e.g., Cl-C4) ester with the alcohol while distilling out water or lower alkanol. In the case of acid-esters less alcohol is used.

In fact, acid-esters made from alkenyl succinic anhydrides do not evolve water. In another method the alkenyl succinic acid or anhydrides can be merely reacted with an appropriate alkylene oxide such as ethylene oxide, or propylene oxide, including mixtures thereof.

Still another sub-category of carboxylic ashless dispersants useful in forming compositions of this invention comprises an alkenyl succinic ester-amide mixture.

These may be made by heating the above-described alkenyl succinic acids, anhydrides or lower alkyl esters with an alcohol and an amine either sequentially or in a mixture.

18 The alcohols and amines described above are also useful in this embodiment. Alternatively, amino alcohols can be used alone or with the alcohol and/or amine to form the ester-amide mixtures. The amino alcohol can contain 1-20 carbon atoms, 1-6 hydroxy groups and 1-4 amine nitrogen atoms. Examples are ethanolamine, 5 diethanolamine, N-ethanol-diethylene triamine, and trimethylol arninomethane.

Here again, the alkenyl group of the succinic ester-amide can be hydrogenated or subjected to other reactions involving olefinic double bonds.

Representative examples of suitable ester-amide mixtures are referred to in U.S. Pat. Nos. 3,184,474; 3,576,743; 3,632,511; 3,804,763; 3,836,471; 3,862,981; 3,936,480; 3,948,800; 3,950,341; 3,957,854; 3,957,855; 3,991,098; 4,071, 548; and 4,173,540.

Yet another sub-category of carboxylic ashless dispersants which can be used comprises the Mannich-based derivatives of hydroxyaryl succinimides. Such compounds can be made by reacting a polyalkenyl succinic anhydride with an aminophenol to produce an N-(hydroxyaryl) hydrocarbyl succinimide which is then reacted with an alkylene diamine or polyalkylene polyamine and an aldehyde (e.g., formaldehyde), in a Mannich-base reaction. Details of such synthesis are set forth in U.S. Pat. No. 4,354,950. As in the case of the other carboxylic ashless dispersants discussed above, the alkenyl succinic anhydride or like acylating agent is derived from a polyolefin, preferably a polyisobutene, having a number average molecular weight of 500 to 5,000, preferably 700 to 2,500, more preferably 700 to 1,400, and especially 800 to 1,200. Likewise, residual unsaturation in the polyalkenyl substituent group can be used as a reaction site as for example, by hydrogenation, or sulfurization.

lype B - Mannich polyamine dispersants. This category of ashless dispersant which can be utilized in the compositions of this invention is comprised of reaction products of an alkyl phenol, with one or more aliphatic aldehydes containing from 1 to 7 carbon atoms (especially formaldehyde and derivatives thereof), and 19 polyamines (especially polyalkylene polyamines of the type described hereinabove).

Examples of these Mannich polyamine dispersants are described in the following U.S.

Patents 2,459,112; 2,962,442; 2,984,550; 3,036,003; 3,166,516; 3,236,770; 3,368,972; 3,413,347; 3,442,808; 3,448,047; 3,454,497; 3,459,661; 3,493,520; 3,539, 633; 3,558,743; 3,586,629; 3,591,598; 3,600,372; 3,634,515; 3,649,229; 3,697,574; 3,703, 536; 3,704,308; 3,725,277; 3,725,480; 3,726,882; 3,736,357; 3,751,365; 3,756,953; 3,793, 202; 3,798,165; 3,798,247; 3,803,039; 3,872,019; 3,980,569; and 4,011,380.

The polyamine group of the Mannich polyamine dispersants is derived from polyamine compounds characterized by containing a group of the structure NH wherein the two remaining valances of the nitrogen are satisfied by hydrogen, amino, or organic radicals bonded to said nitrogen atom. These compounds include ali phatic, aromatic, heterocyclic and carbocyclic polyamines. The source of the oil soluble hydrocarbyl group in the Mannich polyamine dispersant is a hydrocarbyl substituted hydroxy aromatic compound comprising the reaction product of a hydroxy aromatic compound, according to well known procedures, with a hydrocarbyl donating agent or hydrocarbon source. The hydrocarbyl substituent provides substantial oil solubility to the hydroxy aromatic compound and, preferably, is substantially aliphatic in character. Commonly, the hydrocarbyl substituent is derived from a polyolefin having at least about 40 carbon atoms. The hydrocarbon source should be substan tially free from pendant groups which render the hydrocarbyl group oil insoluble.

Examples of acceptable substituent groups are halide, hydroxy, ether, carboxy, ester, amide, nitro and cyano. However, these substituent groups preferably comprise no more than about 10 weight percent of the hydrocarbon source.

The preferred hydrocarbon sources for preparation of the Mannich polyamine dispersants are those derived from substantially saturated petroleum fractions and olefin polymers, preferably polymers of mono-olefins having from 2 to 30 carbon atoms. The hydrocarbon source can be derived, for example, from polymers of olefins such as ethylene, propene, 1-butene, isobutene, 1-octene, 1- methylcyclohexene, 2-butene and 3-pentene. Also useful are copolymers of such olefins with other polymerizable olefinic substances such as styrene. In general, these copolymers should contain at least 80 percent and preferably about 95 percent, on a weight basis, of units derived from the aliphatic mono- olefins to preserve oil solubility. The hydrocarbon source generally contains at least about 40 and preferably at least about 50 carbon atoms to provide substantial oil solubility to the dispersant. The olefin polymers having a number average molecular weight between 600 and 5,000 are preferred for reasons of easy reactivity and low cost. However, polymers of higher molecular weight can also be used. Especially suitable hydrocarbon sources are isobutylene polymers.

The Mannich polyamine dispersants are generally prepared by reacting a hydrocarbyl-substituted hydroxy aromatic compound with an aldehyde and a polyamine. Typically, the substituted hydroxy aromatic compound is contacted with from 0.1 to 10 moles of polyarnine and 0.1 to 10 moles of aldehyde per mole of substituted hydroxy aromatic compound. The reactants are mixed and heated to a temperature above about 80 C to initiate the reaction. Preferably, the reaction is 15 carried out at a temperature from 100 to 250 C The resulting Mannich product has a predominantly benzylamine linkage between the aromatic compound and the polyarnine. The reaction can be carried out in an inert diluent such as mineral oil, benzene, toluene, naphtha, ligroin, or other inert solvents to facilitate control of viscosity, temperature and reaction rate.

Suitable polyamines for use in preparation of the Mannich polyamine dispersants include, but are not limited to, methylene polyamines, ethylene polyamines, butylene polyamines, propylene polyamines, pentylene polyamines, hexylene polyamines and heptylene polyamines. The higher homologs of such an-dnes and related arninoalkyl-substituted piperazines are also useful. Specific examples of 25 such polyarnines include ethylene diamine, triethylene tetramine, tris(2aminoethyl)amine, propylene diamine, pentamethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, decamethylene diamine, di(heptamethylene) triamine, pentaethylene hexamine, di(tri methylene) triamine, 2- 21 heptyl-3-(2-aminopropyl)imidazoHne, 1,3-bis(2-aminoethyl)imidazoline, 1(2-an-finopropyl)piperazine, 1,4-bis(2-aminoethyl)piperazine and 2-methyll-(2-aminobutyl)piperazine. Higher homologs, obtained by condensing two or more of the above mentioned amines, are also useful, as are the polyoxyalkylene polyamines.

The polyalkylene polyamines, examples of which are set forth above, are especially useful in preparing the Mannich polyamine dispersants for reasons of cost and effectiveness. Such polyamines are described in detail under the heading Miamines and Higher Amines" in Kirk-Othmer, Enpyclopedia of Chemical Technology, Second Edition, Vol. 7, pp. 22-39. They are prepared most conveniently by the reaction of an ethylene imine with a ring-opening reagent such as ammonia.

These reactions result in the production of somewhat complex mixtures of polym alkylene polyamines which include cyclic condensation products such as piperazines.

Because of their availability, these mixtures are particularly useful in preparing the Mannich polyamine dispersants. However, it will be appreciated that satisfactory dispersants can also be obtained by use of pure polyalkylene polyamines.

Alkylene diamines and polyalkylene polyamines having one or more hydroxyalkyl substituents on the nitrogen atom are also useful in preparing the Mannich polyamine dispersants. These materials are typically obtained by reaction of the corresponding polyamine with an epoxide such as ethylene oxide or propylene oxide. Preferred hydroxyalkyl-substituted diamines and polyamines are those in which the hydroxyalkyl groups have less than about 10 carbon atom Examples of suitable hydroxyalkyl-substituted diamines and polyamines include, but are not limited to, N(2hydroxyethyl)ethylenediamine,N,N'-bis(2-hydroxyethyl)ethylenediamine,mon o(hydroxypropyl)diethylenetriamine, (di(hydroxypropyl)tetraethylenepentamine and N-(3hydroxybutyl)tetramethylenediamine. Higher homologs obtained by condensation of the above mentioned hydroxyalkyl-substituted diamines and polyamines through amine groups or through ether groups are also useful.

Any conventional formaldehyde yielding reagent is useful for the preparation 22 of the Mannich polyanfine dispersants. Examples of such formaldehyde yielding reagents are trioxane, paraformaldehyde, trioxymethylene, aqueous formalin and gaseous formaldehyde.

Ine C - Polymeric 12o-lyamine dispersants Also suitable for use in the compositions of this invention are polymers containing basic amine groups and oil solubilizing groups (for example, pendant alkyl groups having at least about 8 carbon atoms). Such polymeric dispersants are herein referred to as polymeric polyamine dispersants. Such materials include, but are not limited to, interpolymers of decyl methacrylate, vinyl decyl ether or a relatively high molecular weight olefin with aminoalkyl acrylates and aminoalkyl acrylamides. Examples of polymeric polyamine dispersants are set forth in the following patents: U.S. Pat. Nos. 3,329, 658; 3,449,250; 3,493,520; 3,519,565; 3,666,730; 3,687,849; 3,702,300.

Type D - Post-treated ashless dispersants. Any of the ashless dispersants referred to above as types A-C can be subjected to post-treatment with one or more suitable reagents such as urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, anhydrides of low molecular weight dibasic acids, nitriles, epoxides, phosphorus acids, and phosphorus esters. Such post-treated ashless dispersants can be used in forming the compositions of this invention. Examples of post-treatment procedures and post-treated ashless dispersants are set forth in the following U.S. Patents: U.S. Pat. Nos. 3,036,003; 3,200,107; 3,216,936; 3, 256,185; 3,278,550; 3,312,619; 3,366,569; 3,367,943; 3,373,111; 3,403,102; 3,442,808; 3,455,831; 3,455,832; 3,493,520; 3,502,677; 3,513,093; 3,573, 010; 3,579,450; 3,591,598; 3,600,372; 3,639,242; 3,649,229; 3,649,659; 3, 702,757; and 3,708,522; and 4,971,598.

Mannich-based derivatives of hydroxyaryl succinimides that have been post treated with C.5-C9 lactones such as E-caprolactone and optionally with other post treating agents as described for example in U.S. Pat. No. 4,971,711 can also be utilized in the practice of this invention. U.S. Pat. No. 4,971,711, as well as related U.S. Pat. Nos. 4,820,432; 4,828,742; 4,866,135; 4,866,139; 4,866,140; 4, 866,141; 4,866,142; 4,906,394; and 4,913,830, disclose additional suitable ashlessdispersants 23 which may be utilized.

Metal hydrocarbyl dithiophosphates can be employed in the compositions of this invention, whenever desired. As is well known, metal hyorocarbyl dithiophosphates are usually prepared by reacting_phosphorus pentasulfide with one 5 or more alcohols or phenolic compounds or diols to produce a hydrocarbyl dithiophosphoric acid which is then neutralized with one or more metal-containing bases. When a monohydric alcohol or phenol is used in this reaction, the final product is a metal dihydrocarbyl dithiophosphate. On the other hand, when a suitable diol (e.g., 2,4pentanediol) is used in this reaction, the final product is a 10 metal salt of a cyclic hydrocarbyl dithiophosphoric acid. See, for example, U.S. Pat. No. 3,089,850. Thus typical oil-soluble metal hydrocarbyl dithiophosphates may be represented by the formula S R 10 p 1 -S-m R20 X where R, and R2 are, independently, hydrocarbyl groups or taken together are a single hydrocarbyl group forming a cyclic structure with the phosphorus and two oxygen atoms, preferably a hydrocarbyl-substituted trimethylene group of sufficient carbon content to render the compound oil soluble, M is a metal, and x is an integer corresponding to the valence of M. The preferred compounds are those in which R, and R2 are separate hydrocarbyl groups (i.e., the metal dihydrocarbyl dithiophosphates). Usually the hydrocarbyl groups of the metal dihydrocarbyl dithiophosphates will contain no more than about 50 carbon atoms each although even higher molecular weight hydrocarbyl groups can be present in the compound. 7he hydrocarbyl groups include cyclic and acyclic groups, both saturated and 24 unsaturated, such as alkyl, cycloalkyl, alkenyl, cycloalkenyl, aryl, cycloalkylalkyl, and aralkyl. It will be understood that the hydrocarbyl groups may contain elements other than carbon and hydrogen provided such other elements do not detract from the predominantly hydrocarbonaceous character of the hydrocarbyl group. Thus the hydrocarbyl groups may contain ether oxygen atoms, thioether sulfur atoms, secondary or tertiary amino nitrogen atoms, and/or inert functional groups such as esterified carboxylic: groups, keto groups, and thioketo groups.

lle metals present in the oil-soluble metal dihydrocarbyl dithiophosphates and oil-soluble metal cyclic hydrocarbyl dithiophosphates include such metals as lithium, sodium, potassi=4 copper, magnesiun-4 calcium, zinc, strontium, cadmium, barium, mercury, aluminum, tin, lead, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, and ruthenium, as well as combinations of two or more such metals.

Of the foregoing, the salts containing group 11 metals, aluminum, lead, tin, molybde nun.4 manganese, cobalt, and/or nickel, are preferred. The dihydrocarbyl dithiophosphates of zinc and copper are particularly preferred, with the zinc salts being the most preferred type of compound for use The phosphorodithioic acids from which the metal salts are formed can be prepared by the reaction of about 4 moles of one or more alcohols (cyclic or acyclic) or one or more phenols or mixture of one or more alcohols and one or more phenols (or about 2 moles of one or more diols) per mole of phosphorus pentasulfide, and the reaction may be carried out within a temperature range of from 50 to 200 C The reaction generally is completed in 1 to 10 hours. Hydrogen sulfide is liberated during the reaction.

Another method for the preparation of the phosphorodithioic acids involves reaction of one or more alcohols and/or one or more phenols with phosphorus sesquisulfide in the presence of sulfur such as is described in PCT International Publication No. WO 90/07512. This reaction is conducted at an elevated tem perature, preferably in the range of 85-150 0 C with an overall atomic P:S ratio of at least 23:1.

The alcohols used in forming the phosphorodithioic acids by either of the above methods are preferably primary alcohols, or secondary alcohols. Mixtures thereof are also suitable. The primary alcohols include propanol, butanol, isobutyl alcohol, pentanol, 2-ethyl-l-hexanol, isooctyl alcohol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, octadecanol, and eicosanol. 71e primary alcohols may contain various substituent groups such as halogen atoms, and nitro groups, which do not interfere with the desired reaction. Among suitable secondary alcohols are included 2-butanol, 2-pentanol, 3-pentanol, 2-hexanol, and 5- methyl-2 hexanol. In some cases, it is preferable to utilize mixtures of various alcohols, such as mixtures of 2-propanol with one or more higher molecular weight primary alcohols, especially primary alcohols having from 4 to 13 mixtures preferably contain at least 10 mole percent of 2-propanol, and usually will contain from 20 to 90 mole percent of 2-propanol. In one preferred embodiment, the alcohol comprises 30 to 50 mole percent of 2-propanol, 30 to 50 mole percent isobutyl alcohol and 10 to 30 mole percent of 2-ethyl-l-hexanol.

Other suitable mixtures of alcohols include 2-propanol/butanol; 2propanol/2 butanol; 2-propanol/2-ethyl-l-hexanol; butanol/2-ethyl-l-hexanol; isobutyl alcohol/2 ethyl-1-hexanol; and 2-propanol/tridecanol.

Cycloaliphatic alcohols suitable for use in the production of the phosphorodithioic acids include cyclopentanol, cyclohexanol, methylcyclohexanol, cyclooctanol, and borneol. Preferably, such alcohols are used in combination with one or more primary alkanols such as butanol, and isobutyl alcohol.

Illustrative phenols which can be employed in forming the phosphorodithioic acids include phenol, o-cresol, m-cresol, p-cresol, 4-ethylphenol, and 2, 4-Xylenol. It is desirable to employ phenolic compounds in combination with primary alkanols such propanol, butanol, and hexanol.

26 Other alcohols which can be employed include benzyl alcohol, cyclohexenol, and their ring-alkylated analogs.

It will be appreciated that when mixtures of two or more alcohols and/or phenols are employed in forming the phosphorodithioic acid, the resultant product will normally comprise a mixture of three or more different dihydrocarbyl phosphoro dithioic acids, usually in the form of a statistical distribution in relation to the number and proportions of alcohols and/or phenols used.

Illustrative diols which can be used in forming the phosphorodithioic acids include 2,4-pentanediol, 2,4-hexanediol, 3,5-heptanediol, 7-methyl-2,4- octanediol, neopentyl glycol, 2-butyl-1,3-propanediol, and 2,2-diethyl-1,3- propanediol.

The preparation of the metal salts of the dihydrocarbyl dithiophosphoric acids or the cyclic hydrocarbyl dithiophosphoric acids is usually effected by reacting the acid product with a suitable metal compound such as a metal carbonate, metal hydroxide, metal allcoxide, metal oxide, or other appropriate metal salt. Simply mixing and heating such reactants is normally sufficient to cause the reaction to occur and the resulting product is usually of sufficient purity for use in the practice of this invention. Typically, the salts are formed in the presence of a diluent such as an alcohol, water or a light mineral oil. Neutral salts are prepared by reacting one equivalent of metal oxide or hydroxide with one equivalent of the acid. Basic metal salts are prepared by adding an excess (i.e., more than one equivalent) of the metal oxide or hydroxide with one equivalent of the dihydrocarbyl phosphorodithioic acid or cyclic hydrocarbyl phosphorodithioic acid.

Illustrative metal compounds which may be used in such reactions include calcium oxide, calcium hydroxide, silver oxide, silver carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium ethoxide, zinc oxide, zinc hydroxide, strontium oxide, strontium hydroxide, cadmium oxide, cadmium hydroxide, cadmium carbonate, barium oxide, aluminum oxide, aluminum propoxide, iron 27 carbonate, copper hydroxide, lead oxide, tin butoxide, cobalt oxide, nickel hydroxide, and manganese oxide.

In some cases, incorporation of certain ingredients such as small amounts of metal acetate or acetic acid in conjunction with the metal reactant will facilitate the reaction and provide an improved product. For example,use of up to about 5% of zinc acetate in combination with the required amount of zinc oxide tends to facilitate the formation of zinc dihydrocarbyl dithiophosphates.

Examples of useful metal salts of dihydrocarbyl dithiophosphoric acids, and methods for preparing such salts are found in the prior art such as for example, U.S.

Pat. Nos. 4,263,150; 4,289,635; 4,308,154; 4,322,479; 4,417,990; and 4, 466,895.

Generally speaking, the preferred types of metal salts of dihydrocarbyl dithiophosphoric acids are the oil-soluble metal salts of dialkyl dithiophosphoric acids. Such compounds generally contain alkyl groups having at least three carbon atoms, and preferably the alkyl groups contain up to 10 carbon atoms although as noted above, even higher molecular weight alkyl groups are entirely feasible. A few illustrative zinc dialkyl dithiophosphates include zinc diisopropyl dithiophosphate, zinc dibutyl dithiophosphate, zinc diisobutyl dithiophosphate, zinc di-sec-butyl dithiophosphate, the zinc dipentyl dithiophosphates, the zinc dihexyl dithiophosphates, the zinc diheptyl dithiophosphates, the zinc dioctyl dithiophosphates, the zinc dinonyl dithiophosphates, the zinc didecyl dithlophosphates, and the higher homologs thereof. Mixtures of two or more such metal compounds are often preferred for use such as metal salts of dithiophosphoric acids formed from mixtures of isopropyl alcohol and secondary butyl alcohol; isopropyl alcohol, isobutyl alcohol, and 2-ethylhexyl alcohol; isopropyl alcohol, butyl alcohol, and pentyl alcohol; and isobutyl alcohol and octyl alcohol.

If desired, the metal dihydrocarbyl dithiophosphate additives of the type described above may be treated with an epoxide to form an adduct. In general, the most suitable metal dihydrocarbyl dithiophosphates useful in forming such adducts 28 are the zinc dihydrocarbyl dithiophosphates. The epoxides comprise alkylene oxides and arylalkylene oxides. Typical alkylene oxides which may be used include alkylene oxides having up to about 8 carbon atoms in the molecule, such as ethylene oxide, propylene oxide, 1,2-butene oxide, trimethylene oxide, tetramethylene oxide, butadiene monoepoxide, 1,2-hexene oxide, and epichlorohydrin. The arylalkylene oxides are exemplified by styrene oxide. Other suitable epoxides include, for example, butyl 9,10-epoxystearate, epoxidized soybean oil, epoxidized tung oil, and epoxidized styrene-butadiene copolymer. Procedures for preparing epoxide adducts are known and are reported, for example, in U. S. Pat. No. 3,390,082.

The adduct may be obtained by simply mixing the metal phosphorodithioate and the epoxide. The reaction is usually exothermic and may be carried out within wide temperature limits from 0 0 C to 300 C. Because the reaction is exothermic, it is best carried out by adding one reactant, usually the epoxide, in small increments to the other reactant in order to obtain convenient control of the temperature of the reaction. The reaction may be carried out in a solvent such as benzene, mineral oil, naphtha, or n-hexene.

The chemical structure of the adduct is not known. The adducts obtained by the reaction of one mole of the phosphorodithioate with from 0.25 mole to 5 moles, usually up to 0.75 mole or 0.5 mole of a lower alkylene oxide, particularly ethylene oxide and propylene oxide, are the preferred adducts.

Another type of metal dihydrocarbyl phosphorodithioate additives which can be used in the compositions of this invention comprises mixed-acid metal salts of a combination of (a) at least one phosphorodithioic acid of the formula (RO)(WO)PSSEI, as exemplified above (R and R' being, independently, hydrocarbyl groups (or taken together, a single hydrocarbyl group forming a cyclic moiety with the two oxygen atoms and the phosphorus atom) of sufficient carbon content to render the salt soluble in lubricating oil), and (b) at least one aliphatic or alicyclic carboxylic acid. The carboxylic acid may be a monocarboxylic or polycarboxylic acid, usually 29 containing from 1 to 3 carboxy groups and preferably only one. It may contain from 2 to 40, preferably from 2 to 20 carbon atoms, and advantageously 5 to 20 carbon atoms. The preferred carboxylic acids are those having the formula WCOOH, wherein W is an aliphatic or alicyclic hydrocarbon-based radical preferably free from acetylenic unsaturation. Suitable acids include the butanoic, pentanoic, hexanoic, octanoic, nonanoic, decanoic, dodecanoic, octadecanoic and eicosanoic acids, as well as olefinic acids such as oleic, linoleic, and linolenic acids and linoleic acid dimer.

For the most part, W is a saturated aliphatic group and especially a branched alkyl group such as the isopropyl or 3-heptyl group. Illustrative polycarboxylic acids are succinic, alkyl- and alkenylsuccinic, adipic, sebacic and citric acids.

The mixed-acid metal salts may be prepared by merely blending a metal salt of a phosphorodithioic acid with a metal salt of a carboxylic acid in the desired ratio.

The ratio of equivalents of phosphorodithioic to carboxylic acid salts is between 03:1 and 200:1. Advantageously, the ratio can be from 0.5:1 to 100:1, preferably from 0.5:1 to 50:1, and more preferably from 0.5:1 to 20:1. Further, the ratio can be from 0.5:1 to 4.5:1, preferably 23:1 to 4.25:1. For this purpose, the equivalent weight of a phosphorodithioic acid is its molecular weight divided by the number of -PSSH groups therein, and that of a carboxylic acid is its molecular weight divided by the number of carboxy groups therein.

A second and preferred method for preparing the mixed-acid metal salts useful in this invention is to prepare a mixture of the acids in the desired ratio and to react the acid mixture with a suitable metal base. When this method of preparation is used, it is frequently possible to prepare a salt containing an excess of metal with respect to the number of equivalents of acid present; thus, mixed-acid metal salts containing as many as two equivalents and especially up to about 1.5 equivalents of metal per equivalent of acid may be prepared. The equivalent of a metal for this purpose is its atomic weight divided by its valence.

Variants of the above-described methods may also be used to prepare the mixed-acid metal salts useful in this invention. For example, a metal salt of either acid may be blended with an acid of the other, and the resulting blend reacted with additional metal base.

Suitable metal bases for the preparation of the mixed-acid metal salts include the oxides, hydroxides, alkoxides and other basic salts of the metals previously enumerated, and in some cases the free metals themselves. Examples are sodium hydroxide, potassium hydroxide, magnesium oxide, calcium hydroxide, zinc oxide, lead oxide, and nickel oxide.

The temperature at which the mtxed-acid metal salts are prepared is generally between 30 0 C and 150 0 C, preferably up to 125 0 C. If the niixed-acid salts are prepared by neutralization of a mixture of acids with a metal base, it is preferred to employ temperatures above about 50 0 C and especially above about 75 0 C. It is frequently advantageous to conduct the reaction in the presence of a substantially inert, normally liquid organic diluent such as naphtha, benzene, xylene, or mineral oil. If the diluent is mineral oil, it frequently need not be removed before using the mixed-acid metal salt as an additive for lubricants or functional fluids.

U. S. Patents 4,308,154 and 4,417,970 describe procedures for preparing these mixed-acid metal salts and disclose a number of examples of such mixed salts.

Metal hydrocarbyl dithiocarbamates constitute another type of oil-soluble metal salts which can be used in the compositions of this invention. These are salts of one or more dithiocarbamic acids of the formula WN-CSS11 wherein R and R' are each independently hydrocarbyl groups in which the total number of carbon atoms in R and R' is sufficient to render the metal salt oil-soluble. R and R' taken together may represent a polymethylene or alkyl substituted polymethylene group thereby forming a cyclic compound with the nitrogen atom (i.e., a monocyclic hydro carbyl dithiocarbamate). Generally the hydrocarbyl groups will each contain at least two carbon atoms and may contain 50 or more carbon atoms. The metal component 31 present in the dihydrocarbyl (or monocyclic hydrocarbyl) dithiocarbamate salts may be a monovalent metal or a polyvalent metal, although polyvalent metals are preferred as the salts of the polyvalent metals tend to possess better solubility in oils of lubricating viscosity. Thus although the alkali metal monocyclic hydrocarbyl or dihydrocarbyl dithiocarbamates may be used if oil-soluble, the preferred salts include, for example, salts of one or more of the alkaline earth metals, zinc, cadmiun-4 magnesium, tin, molybdenun4 iron, copper, nickel, cobalt, chromium, and lead. The Group H metal dihydrocarbyl dithiocarbamates are preferred.

In selecting a metal salt of a dithiocarbamic: acid to be used in the compositions of this invention, R, W, and the metal may be varied so long as the metal salt is adequately oil-soluble. The nature and type of the mineral base stock and the type of service contemplated for the treated lubricating oil should be taken into consideration in the choice of metal salt.

The metal constituent of the metal dihydrocarbyl dithiocarbamate is usually a simple metal cation. However in the case of certain polyvalent metal derivatives such as the tin and lead compounds, the metal constituent itself may be hydrocarbyl substituted (e.g., (RWN-CSS-),MR1R., where M is a polyvalent metal, R, R', R, and R. are, independently, hydrocarbyl groups (and, optionally R and R' taken together are a single cyclic hydrocarbyl group) in which the total number of carbon atoms is sufficient to render the compound oil-soluble, and x is an integer sufficient to satisfy the remaining valence(s) of M. Techniques described for example in U.S. Pat. No.

2,786,814 may be employed for preparing such hydrocarbyl-substituted metal dithiocarbamates.

Mixtures of metal salts of dithiocarbamic acids also are contemplated as being useful in the present invention. Such mixtures can be prepared by first preparing mixtures of dithiocarbarnic acids and thereafter converting said acid mixtures to metal salts, or alternatively, metal salts of various dithiocarbamic acids can be prepared and thereafter mixed to give the desired product. Thus, the mixtures which can be 32 incorporated in the compositions of the invention may be merely the physical mixture of the different metallic dithiocarbamic compounds, or compounds having different dithiocarbamate groupings attached to the same polyvalent metal atoms.

Examples of alkyl groups are ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, decyl, dodecyl, tridecyl, pentadecyl and hexadecyl groups including isomeric forms thereof. Examples of cycloalkyl groups include cyclohexyl and cycloheptyl groups, and examples of aralkyl groups include benzyl and phenethyl. Examples of polymethylene groups include penta- and hexamethylene groups, and examples of alkyl-substituted polymethylene groups include methyl pentamethylene, and dimethyl pentamethylene.

Specific examples of the metal dithiocarbamates useful in the compositions of this invention include zinc dibutyldithiocarbamate, zinc diamyIdithiocarbamate, zinc di(2-ethylhexyl)dithiocarbamate, cadmium dibutyldithiocarbamate, cadmium dioctyldithiocarbamate, cadmium octylbutyldithiocarbamate, magnesium dibutyldithiocarbamate, magnesium dioctyldithiocarbamate, cadmium dicetyldithiocarbainate, copper diamyldithiocarbamate, sodium dioctadecyldithiocarba mate, lead dioctyldithiocarbamate, nickel diheptyldithiocarbamate, and calcium di-2 ethylhexyidithiocarbamate.

The various metal salts of dithiocarbamic acids utilized in the compositions of this invention are well known in the art and can be prepared by known techniques.

Thorn and Ludwig, The Dithiocarbamates and Related Compounds Elsevier Publishing Company, 1962, pages 12 to 37 (and references cited therein); Delepine,

Compt. Rend., L44, 1125 (1907); Whitby et al, Proceedings and Transactions of The RQyal Socieiy of Canada XITH, 111-114 (1924) (and references cited therein),

Chabrier et al, Bulletin de la Societe Chimique De France, 1950, pages 43 et seq.

(and references cited therein), and U. S. Pat. Nos. 1,622,534; 1,921,0911 2,046,875;

33 2,046,876; 2,258,847; 2,406,960; 2,443,160; 2,450,633; 2,492,314; 2,580, 274; 3,513,094; 3,630,897; 4,178,258; and 4,226,733.

While boron is not a metallic element, boron tris(dihydrocarbyl dithiocarbamates) can be used in the compositions of this invention, either individually or in combination with one or more metal dihydrocarbyl dithiocar bamates. Methods suitable for the production of such boron dithiocarbamates are set forth in U.S. Pat. No. 4,879,071.

Derivatives of metal dihydrocarbyl dithiocarbamates may be used in addition to or in lieu of the metal dihydrocarbyl dithiocarbamates. Such derivatives include dithiocarbamate-derived phosphates such as are described in U.S. Pat. No. 4,919,830, reaction products of NN-diorganodithiocarbamates with thionyl chloride such as are described in U.S. Pat. No. 4,867,893, N,N-diorganodithiocarbamate- alkylthiosulfinyl halide reaction products such as are described in U.S. Pat. No. 4,859,356, reaction products of halogenated EPDM terpolymers and alkali metal dialkyldithiocarbamate such as are described in U.S. Pat. No. 4,502,972, and sulfurized metal dihydrocarbyl dithiocarbamates such as are described in U.S. Pat. No. 4,360,438, among others. In addition, the metal dihydrocarbyl dithiocarbamates may be used in combination with other carbamate compounds such as for example, a 1,2-dicarbethoxyethyl dialkyldi thiocarbamate such as is disclosed in U.S. Pat. No. 4,479,883; or a mercaptoalkanoic acid dithiocarbamate of the type described in U.S. Pat. No. 3,890,363.

Metal-containing detergents can be employed in the compositions of this invention. These components are exemplified by oil-soluble or oildispersible basic salts of alkali or alkaline earth metals with one or more of the following acidic substances (or mixtures thereof): (1) sulfonic acids, (2) carboxylic acids, (3) salicylic acids, (4) alkylphenols, (5) sulfurized alkylphenols, (6) organic phosphorus acids characterized by at least one direct carbon-to- phosphorus linkage. Such organic phosphorus acids include those prepared by the treatment of an olefin polymer (e.g., polyisobutene having a molecular weight of 1000) with a phosphorizing- agent such 34 as phosphorus trichloride, phosphorus heptasulfide, phosphorus pentasulfide, phosphorus trichloride and sulfur, white phosphorus and a sulfur halide, or phosphorothioic chloride. lle most commonly used salts of such acids are those of sodium, potassium, lithiun4 calcium, magnesium, strontium and barium. The salts for use in this embodiment are preferably basic salts having a TBN of at least 50, preferably above 100, and most preferably above 200. In this connection, TBN is determined in accordance with ASTM D-2896-88.

The term "basic salC is used to designate metal salts wherein the metal is present in stoichiometrically larger amounts than the organic acid radical. Tle commonly employed methods for preparing the basic salts involve heating a mineral oil solution of an acid with a stoichiometric excess of a metal neutralizing agent such as the metal oxide, hydroxide, carbonate, bicarbonate, or sulfide at a temperature of about 50 0 C, and filtering the resulting mass. The use of a "promoter" in the neutralization step to aid the incorporation of a large excess of metal likewise is known.

Examples of compounds useful as the promoter include phenolic substances such as phenol, naphthol, alkylphenol, thiophenol, sulfurized alkylphenol, and condensation products of formaldehyde with a phenolic substance; alcohols such as methanol, 2-propanol, octyl alcohol, Cellosolve alcohol, Carbitol alcohol, ethylene glycol, stearyl alcohol, and cyclohexyl alcohol; and amines such as aniline, phenylenediamine, phenothiazine, phenyl-betanaphthylamine, and dodecylarnine. A particularly effective method for preparing the basic salts comprises mixing an acid with an excess of a basic alkaline earth metal neutralizing agent and at least one alcohol promoter, and carbonating the mixture at an elevated temperature such as 60 to 2001 C.

Examples of suitable metal-containing detergents include, but are not limited to, the basic or overbased salts of such substances as lithium phenates, sodium phenates, potassium phenates, calcium phenates, magnesium phenates, sulfurized lithium phenates, sulfurized sodium phenates, sulfurized potassiurn. phenates, sulfur ized calcium phenates, and sulfurized magnesium phenates wherein each aromatic group has one or more aliphatic groups to impart hydrocarbon solubility; lithium sulfonates, sodium sulfonates, potassium sulfonates, calcium sulfonates, and magnesium sulfonates wherein each sulfonic acid moiety is attached to an aromatic nucleus which in turn usually contains one or more aliphatic substituents to impart hydrocarbon solubility; lithium salicylates, sodium salicylates, potassium salicylates, calcium salicylates, and magnesium salicylates wherein the aromatic moiety is usually substituted by one or more aliphatic substituents to impart hydrocarbon solubility; the lithium, sodium, potassium, calcium and magnesium salts of hydrolyzed phosphosulfurized olefins having 10 to 2,000 carbon atoms or of hydrolyzed phosphosulfurized alcohols and/or aliphatic-substituted phenolic compounds having 10 to 2,000 carbon atoms; lithium, sodiun4 potassium, calcium and magnesium salts of aliphatic carboxylic acids and allphatic-substituted cycloaliphatic carboxylic acids; and many other similar alkali and alkaline earth metal salts of oil-soluble organic acids. Mixtures of basic or overbased salts of two or more different alkali and/or alkaline earth metals can be used. Likewise, basic or overbased salts of Mixtures of two or more different acids or two or more different types of acids (e.g., one or more calcium phenates with one or more calcium sulfonates) can also be used. While rubidium, cesium and strontium salts are feasible, their expense renders them impractical for most uses. Likewise, while barium salts are effective, the status of barium as a heavy metal under a toxicological cloud renders barium salts less preferred for present-day usage.

As is well known, overbased metal detergents are generally regarded as containing overbasing quantities of inorganic bases, probably in the form of micro dispersions or colloidal suspensions. Thus the terms "oilsoluble" and "oil-dispersible" are applied to these metal-containing detergents so as to include metal detergents wherein inorganic bases are present that are not necessarily completely or truly oilsoluble in the strict sense of the term, inasmuch as such detergents when mixed into base oils behave in much the same way as if they were fully and totally dissolved in the oil.

Collectively, the various basic or overbased detergents referred to hereinabove, 36 have sometimes been called, quite simply, basic alkali metal or alkaline earth metalcontaining organic acid salts.

Methods for the production of oil-soluble basic and overbased alkali and alkaline earth metal-containing detergents are well known to those skilled in the art and are extensively reported in the patent literature. See for example, the disclosures of U.S. Pat. Nos. 2,451,345; 2,451,346; 2,485,861; 2,501, 731; 2,501,732; 2,585,520; 2,671,758; 2,616,904; 2,616,905; 2,616,906; 2, 616,911; 2,616,924; 2,616,925; 2,617,049; 2,695,910; 3,178,368; 3,367,867; 3,496,105; 3,629,109; 3,865,737; 3,907,691; 4,100,085; 45129,589; 4,137, 184; 4,148,740; 4,212,752; 4,617,135; 4,647,387; 4,880,550; GB

Published Patent Application 2,082,619 A, and European Patent Publication Nos.

121,024 B 1 and 259,974 A2.

For certain applications, the compositions can contain metal-free sulfurcontaining antiwear and/or extreme pressure agents. Examples are included within the categories of dihydrocarbyl polysulfides; sulfurized olefins; sulfurized fatty acid esters of both natural and synthetic origins; trithiones; sulfurized thienyl derivatives; sulfurized terpenes; sulfurized oligomers of C2-C8 monoolefins; and sulfurized DielsAlder adducts such as those disclosed in U.S. reissue patent Re 27,331. Specific examples include sulfurized polyisobutene of Rn 1,100, sulfurized isobutylene, sulfurized diisobutylene, sulfurized triisobutylene, dicyclohexyl polysulfide, diphenyl polysuffide, dibenzyl polysulfide, dinonyl polysulfide, and mixtures of di-tert-butyl polysulfide such as mixtures of di-tert-butyl trisulfide, di-tert-butyl tetrasulfide and ditert-butyl pentasulfide, among others. Combinations of such categories of sulfurcontaining antiwear and/or extreme pressure agents can also be used, such as a combination of sulfurized isobutylene and di-tert-butyl trisulfide, a combination of sulfurized isobutylene and dinonyl trisulfide, and a combination of sulfurized tall oil and dibenzyl polysulfide.

The most preferred oil-soluble metal-free sulfur-containing antiwear and/or extreme pressure agents from the cost-effectiveness standpoint are the sulfurized 37 olefins containing at least 30% by weight of sulfur, the dihydrocarbyl polysulfides containing at least 25% by weight of sulfur, and mixtures of such sulfurized olefins and polysulfides. Of these materials, sulfurized isobutylene having a sulfur content of at least 40% by weight and a chlorine content of less than 0.2% by weight is the most especially preferred material. Methods of preparing sulfurized olefins are set forth in U.S. Pat. Nos. 2,995,569; 3,673,090; 3,703,504; 3,703,505; 3,796,661; and 3,873,454. Also useful are the sulfurized olefin derivatives described in U.S. Pat. No. 4,654,156.

Other types of antiwear and/or extreme pressure additives that can be used in the compositions of this invention include, for example, esters of boron acids, esters of phosphorus acids, amine salts of phosphorus acids and acid esters, higher carboxylic acids and derivatives thereof, and chlorine-containing additives.

Esters of boron acids which may be used include borate, metaborate, pyroborate and biborate esters of monohydric and/or polyhydric alcohols and/or phenols, such as trioctyl borate, tridecyl borate, 2-ethylhexyl pyroborate, isoamyl metaborate, trixylyl borate, and (butyl)(2,4-hexanediyl)borate.

Typical esters of phosphorus acids which may be used as antiwear and/or extreme pressure additives include trihydrocarbyl phosphites, phosphonates and phosphates, and dihydrocarbyl phosphites; such as tricresyl phosphate, tributyl phosphite, tris(2-chloroethyl)phosphate and phosphite, dibutyl trichloromethyl phosphonates, di(n-butyl)phosphite, triphenyl phosphite, and tolyl phosphinic acid dipropyl ester.

Among the amine salts of phosphorus acids and phosphorus acid-esters which can be employed are amine salts of partially esterified phosphoric, phosphorous, phosphonic, and phosphinic acids and their partial or total thio analogs such as partially esterified monothiophosphoric, dithiophosphoric, trithiophosphoric and tetrathiophosphoric acids; and amine salts of phosphonic acids and their thio analogs.

38 Specific examples include the dihexylammonium salt of dodecylphosphoric acid, the diethyl hexyl ammonium salt of dioctyl dithiophosphoric acid, the octadecylammonium salt of dibutyl thiophosphoric acid, the dilaurylammonium salt of 2-ethylhexylphosphoric acid, the dioleyl ammonium salt of butane phosphonic acid, and analogous compounds.

Ifigher carboxylic acids and derivatives which can be used as antiwear and/or extreme pressure additives are illustrated by fatty acids, dimerized and trimerized unsaturated natural acids (e.g., linoleic) and esters, amine, ammonia, and metal (particularly lead) salts thereof, and amides and imidazoline salt and condensation products thereof, oxazolines, and esters of fatty acids, such as ammonium di-(linoleic) acid, lard oil, oleic acid, animal glycerides, and lead stearate.

Suitable chlorine-containing additives include chlorinated waxes of both the paraffinic and microcrystalline type, polyhaloaromatics such as diand trichlorobenzene,trifluoromethylnaphthalenes,perchlorobenzene, pentachlorophe noI and dichloro diphenyl trichloroethane. Also. useful are chlorosulfurized olefins and olefinic waxes and sulfurized chlorophenyl methyl chlorides and chloroxanthates. Specific examples include chlorodibenzyl disulfide, chlorosulfurized polyisobutene of Rn 600, chlorosulfurized pinene and chlorosulfurized lard oil.

Seal performance improvers (elastomer compatibility additives) can be used in the compositions of this invention. Known materials of this type include dialkyl diesters such as dioctyl sebacate, aromatic hydrocarbons of suitable viscosity such as Panasol AN-3N, products such as Lubrizol 730, polyol esters such as Emery 2935, 2936, and 2939 esters from the Emery Group of Henkel Corporation and Hatcol 2352, 2962, 2925, 2938, 2939, 2970, 3178, and 4322 polyol esters from Hatco Corporation. Generally speaking the most suitable diesters include the adipates. azelates, and sebacates Of C8-C13 alkanols (or mixtures thereof), and the phthalates Of C4-C13 alkanols (or mixtures thereof). Mixtures of two or more different types of diesters (e.g., dialkyl adipates and dialkyl azelates) can also be used. Examples of 39 such materials include the n-octyl, 2-ethylhexyl, isodecyl, and tridecyl diesters of adipic: acid, azelaic: acid, and sebacic acid, and the n-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and tridecyl diesters of phthalic acid.

Antioxidants can be used, such as one or more phenolic antioxidants, aromatic an-fine antioxidants, sulphurized phenolic antioxidants, and organic phosphites, among others. Examples include 2,6-di-tert-butylphenol, liquid mixtures of tertiary butylated phenols, 2,6-di-tert-butyl-4-methylphenol, 4,4'-methylenebis(2,6-di- tertbutylphenol), 2,T-methylenebis(4-methyl-6-tert-butylphenol), nlLxed methylene-bridged polyalkyl phenols, 4,4'-thiobis(2-methyl6-tert-butylphenol), N,N'-di-sec-butyl p-phenylenediamine, 4-isopropylaminodiphenyl amine, phenyl-a-naphthyl amine, and phenyl-,8naphthyl amine.

Corrosion inhibitors comprise another type of optional additive for use in this invention. Thus use can be made of dimer and trimer acids, such as are produced from tall oil fatty acids, oleic acid, or linoleic acid. Products of this type are currently available from various commercial sources, such as, for example, the dimer and trimer acids sold under the HYSTRENE trademark by the Humco Chenfical Division of Witco Chemical Corporation and under the EMPOL trademark by Emery Chemi cals. Another useful type of corrosion inhibitor for use in the practice of this inven tion are the alkenyl succinic acid and alkenyl succinic anhydride corrosion inhibitors such as, for example, tetrapropenyIsuccinic acid, tetrapropenyIsuccinic anhydride, tetradecenylsuccinic acid, tetradecenyIsuccinic anhydride, hexadecenyIsuccinic acid, and hexadecenyIsuccinic anhydride. Also useful are the half esters of alkenyl succinic acids having 8 to 24 carbon atoms in the alkenyl group with alcohols such as the polyglycols. Other suitable corrosion inhibitors include ether amines; acid phosphates; amines; polyethoxylated compounds such as ethoXylated amines, ethoxy lated phenols, and ethoxylated alcohols; imidazolines; and aminosuccinic acids or derivatives thereof. Materials of these types are well known to those skilled in the art and a number of such materials are available as articles of commerce.

Foam inhibitors are likewise suitable for use as optional components in the compositions of this invention. These include silicones, polyacrylates, and surfactants. Various antifoam agents are described inFoam Control Agents by H. T. Kerner (Noyes Data Corporation, 1976, pages 125-176). Mixtures of silicone-type antifoam agents such as the liquid dialkyl silicone polym-er-with various other substances are also effective. Typical of such mixtures are silicones, mixed with an acrylate polymer, silicones mixed with one or more an-dnes, and silicones mixed with one or more amine carboxylates.

Copper corrosion inhibitors constitute another class of additives suitable for inclusion in the compositions of this invention. Such compounds include thiazoles, triazoles and thiadiazoles. Examples of such compounds include benzotriazole, tolyltriazole, octyltriazole, decyltriazole, dodecyltriazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4thiadiazole, 2-mercapto-5-hydrocarbylthio- 1,3,4-thiadiazoles, 2 - m e r c a p t o - 5 - h y d r o c a r b y 1 d i t h i o - 1, 3, 4 - t h i a d i a z o 1 e s, 2,5-bis(hydrocarbylthio)-1,3,4-thiadiazoles, and 2,5(bis)hydrocarbyldithio)-1,3,4-thia- diazoles. The preferred compounds are the 1,3,4-thiadiazoles, a number of which are available as articles of commerce.

The compositions of this invention may also contain friction modifiers such as aliphatic amines or ethoxylated aliphatic amines, aliphatic fatty acid amides, aliphatic carboxylic acids, aliphatic carboxylic esters, aliphatic carboxylic esteramides, aliphatic phosphonates, aliphatic phosphates, aliphatic thiophosphonates, and aliphatic thiophosphates, wherein the aliphatic group usually contains above about eight carbon atoms so as to render the compound suitably oil soluble. Also suitable are aliphatic substituted succinimides formed by reacting one or more aliphatic succinic acids or anhydrides with ammonia.

Still other components useful in the compositions of this invention are lubricity agents such as sulfurized fats, sulfurized isobutylene, dialkyl polysulfides, and sulfur-bridged phenols such as nonylphenol polysulfide. Air release agents, pour 41 point depressants, demulsifiers, and dyes, can also be included in the compositions of this invention.

In selecting any of the foregoing optional additives, it is of course important to ensure that the selected component(s) are soluble in the oleaginous liquid, are compatible with the other components of the composition, and do not interfere significantly with the low temperature viscosity properties desired in the overall fin ished oleaginous composition.

These additives can of course be blended into the compositions of this invention individually or in various sub-combinations. However it is usually preferable to introduce the additives into the composition in the form of an additive package or concentrate (sometimes variously referred to as ad-packs, or DI packs), as this minimizes blending errors, simplifies blending procedures and takes advantage of the compatibility and mutual solubility characteristics of the additive concentrate.

Typical additive concentrates which may be used in the compositions of this invention are set forth in Examples A through K below. It will be understood and appreciated that these additive concentrates are presented for purposes of illustration only, and are not intended to constitute, and should not be construed as constituting, limitations on the scope of this invention.

EXAMPLE A

A concentrate ("DI-pack') is formed from the following components:

67.56% Phosphorus- and boron-containing ashless dispersant; 2.69% Ethoxylated amines; 0.72% Tolyltriazole, (CobratecIT-100); 1.06% Silicone antifoam agent (4% solution in hydrocarbon); 4.66% Bis-(p-nonylphenyl)amine (Naugalube 438L); 0.90% Calcium phenate3; 0.90% Octanoic acid; 42 8.60% Sulfurized fat' 12.91% Mineral oil diluent.

1 Prepared as in Example 1A of U.S. 4,857,214, and this compo nent contains approximately 25% mineral oil diluent.

2 A combination of 2.24% Ethomeen T-12 (Akzo Chemical, Inc.) and 0.45% Tomah PA-14 (Exxon Chemical Company).

3 OLOA 216C (Chevron Chemical Company).

4 Sulperm 10S (Keil Products Division of Ferro Corporation).

EXAMPLE B

A concentrate is formed from the following components:

67.56% Phosphorus- and boron-containing ashless dispersant'; 2.95% Ethoxylated amine 2; 0.72% 2-(dodecyldithio)-5-mercapto-1,3,4-thiadiazole; is 1.06% Silicone antifoam agent (4% solution in hydrocarbon); 4.66% Bis-(p-nonylphertyl)amine (Naugalube 438L); 1.80% SurfactanO; 0.90% Calcium phenate; 0.90% Octanoic acid; 19.45% Mineral oil diluent.

1 Prepared as in Example 1A of U.S. 4,857,214, and this component contains approximately 25% mineral oil diluent.

2 Ethomeen T-12.

3 Pluronic L-81.

4 OLOA 225.

43 EXAMPLE C

A concentrate is formed from the following components:

67.56% Phosphorus- and boron-containing ashless dispersant; 2.69% Ethoxylated amind; 0.72% Benzotriazole (Cobratec 99); 1.06% Silicone antifoam agent (4% solution in hydrocarbon); 4.66% Bis-(p-nonylphertyl)amine (Naugalube 438L); 1.62% SurfactantO; 1.05% Octanoic acid; 4.45% Sulfurized fat4; 16.19% Mineral oil diluent.

*2 Tomah PA-14.

3 A combination of 1.14% PC 1244 and 0.48% Pluronic L-81.

4 Sulperm 10S.

EXAMPLE D

A concentrate is formed from the following components:

67.56% Phosphorus- and boron-containing ashless dispersane; 3.44% Ethoxylated amineS2; 0.72% 2,5-di-(methylthio)-1,3,4-thiadiazole; 1.06% Silicone antifoam agent (4% solution in hydrocarbon); 4.66% Ethyl antioxidant 728 (Ethyl Corporation); 1.48% SurfactanO; 0.90% Calcium phenate; 0.90% Octanoic acid; 2.75% Sulfurized isobutylene; 16.53% Mineral oil diluent.

44 1 Prepared as in Example 1A of U.S. 4,857,214, and this component contains approximately 25% mineral oil diluent. 2 A combination of 1.88% Ethomeen T-12 and 1.56% Tomah PA-14.

3 Mazawet 77.

4 OLOA 218A EXAMPLE E

A concentrate is formed from the following components:

67.56% Phosphorus- and boron-containing ashless dispersanti 2.69% Ethoxylated amines 2; 0.72% 2-(dodecyldithio)-5-mercapto-1,3,4-thiadiazole; 1.06% Silicone antifoam agent (4% solution in hydrocarbon); 4.66% Bis-(p-nonylphenyl)amine (Naugalube 438L); 1.62% SurfactantO; 0.90% Calcium phenate; 0.90% Octanoic acid; 8.60% Sulfurized fat; 11.29% Mineral oil diluent.

2 A combination of 1.79% Ethomeen T-12 and 0.90% Tomah PA-1.

3 A combination of 0.54% PC 1244, 0.90% Mazawet 77, and 0.18% Pluronic L-81.

4 OLOA 216C.

Sulperm 10S.

EXAMPLE F

A concentrate is formed from the following components:

67.56% Phosphorus- and boron-containing ashless dispersane; 2.95% Ethoxylated amineJ; 0.72% 2-(dodecyldithio)-5-mercapto-1,3,4-thiadiazole; 1.06% Silicone antifoam agent (4% solution in hydrocarbon); 4.66% Bis-(p-nonylphenyl)amine (Naugalube 438L); 1.85% SurfactanO; 0.90% Calcium phenate; 0.90% Octanoic acid; 7.42% Sulfurized fat; 11.98% Mineral oil diluent.

2 A combination of 1.79% Ethomeen T-12 and 0.90% Tomah PA-14.

3 PC 1244.

4 OLOA 218A Sulperm 60-93 (Keil Products Division of Ferro Corporation).

EXAMPLE G

A concentrate is formed from the following components:

67.56% Phosphorus- and boron-containing ashless dispersant'; 2.35% Ethoxylated amineS2; 0.70% Tolyltriazole; 1.06% Silicone antifoam agent (4% solution in hydrocarbon); 8.65% Ethyl antioxidant 728 0M50 (Ethyl Corporation); 1.58% Surfactants; 0.90% Calcium phenate4; 0.90% Octanoic acid; 46 4.42% Sulfurized fat; 11.88% Mineral oil diluent.

2 A combination of 1.40% Ethomeen T-12 and 0.95% Tomah PA-14.

3 A combination of 0.95% PC 1244 and 0.63% Mazawet 77.

4 OLOA 216C.

Sulperm 60-93.

EXAMPLE H

A concentrate is formed from the following components:

67.57% Phosphorus- and boron-containing ashless dispersant'; 1.79% Ethoxylated aminJ; 0.72% 2-(dodecyidithio)-5-mercapto-1,3,4-thiadiazole; is 1.08% Silicone antifoam agent (4% solution in hydrocarbon); 4.66% Bis-(p-nonylphertyl)amine (Naugalube 438L); 1.98% SurfactantS3; 0.90% Calcium phenate4; 0.90% Octanoic acid; 0.54% M-544 (Monsanto Company); 8.60% Sulfurized fae; 11.26% Mineral oil diluent (45N).

2 Ethomeen T-12.

3 A combination of 0.90% Tomah PA-14, 0.90% Mazawet 77, and 0.18% Pluronic L-81.

47 4 OLOA 216C.

5. Sulperm 10S EXAMPLE I_

A concentrate is formed from the components used in the production of Paranox 445 additive (Exxon Chemical Company) except that all or substantially all polymeric viscosity index improver that is not an acrylic polymeric viscosity index improver, if any, (and any diluent employed in conjunction with any such acrylic viscosity index improver) employed in Paranox 445 additive is eliminated. By "substantially all" in this and ensuing examples is meant that any amount of non-acrylic-type viscosity index improver, if any, that is present in the commercial additive concentrate does not destroy the low temperature viscometrics afforded by this invention. More specifically, the addition at a suitable treat level of an additive concentrate containing a non-acrylic-type viscosity index improver to an oleaginous composition of this invention should not convert the oleaginous composition from one which has a Brookfield viscosity of 20,000 cP or less at -40 0 C when devoid of the concentrate to an oleaginous composition that has a Brookfield viscosity above 20,000 cP at -40 C when the concentrate has been dissolved therein.

EXAMPLEJ

A concentrate is formed from the components used in the production of Lubrizoll' LZ-6715D additive (The Lubrizol Corporation) except that all or substantially all polymeric viscosity index improver that is not an acrylic-type viscosity index improver, if any, (and any diluent employed in conjunction with such non-acrylic- type viscosity index improver, if any) employed in Lubrizoll' LZ-6715D additive is eliminated.

EXAMPLE K

Seven concentrates are formed from the components used in the production of the following seven commercial products of The Lubrizol Corporation: Lubrizoll, LZ 6704 additive, Lubrizoll' LZ-7900 additive, Lubrizoll' LZ-7901 additive, Lubrizoll' 48 LZ-7907 additive, Lubrizoll' LZ-7925 additive, Lubrizo10 LZ-7993 additive, and Lubrizoll' LZ-7993A additive. In each case all or substantially all of any polymeric viscosity index improver that is not an acrylic-type viscosity index improver, if any, (and any diluent employed in conjunction with such non-acrylic-type viscosity index improver, if any), employed in the particular commercial product of Lubrizol is eliminated.

EXAMPLE L

Four concentrates are formed from the components used in the production of the following four commercial products of Exxon Chemical Company: Paramins ECA 9172 additive, Paramins ECA 11998 additive, Paranox 440 additive, and Paranox 442 additive. In each case all or substantially all of any polymeric viscosity index im prover that is"not an acrylic-type viscosity index improver, if any, (and any diluent employed in conjunction with such non-acrylic-type viscosity index improver, if any) employed in the particular commercial product of Exxon Chemical Company is eli minated.

Proportions of Additives In general, the additive components used in the compositions of this invention are employed in minor amounts sufficient to improve the performance characteristics and properties of the base fluid. The amounts will thus vary in accor dance with such factors as the severity and type of service for which the composition is intended, the performance characteristics desired in the finished composition, the makeup of the particular base oil composition, the identity of the additives being used, and other similar considerations. However, generally speaking, the following concentrations (weight percent) of the components (active ingredients) in the base fluids are illustrative:

Typical Preferred Range Range Dispersant 0-20 0.1-8 49 Antiwear Agent 0-6 0.001-4 Detergents/Rust Inhibitor 0-20 0.1-5 Antioxidant 0-5 0.1-3 Corrosion inhibotor 0-5 0.005-3 Seal performance improver 0-30 1-20 Foam inhibitor 0-1 0.001-0.5 Copper corrosion inhibitor 0-5 0.01-2 Friction modifier 0-5 0.01-2 Pour Point Depressant 0-3 04-1 Dye 0-0.05 0-0.035 It is to be noted that some additives are multifunctional additives capable of contributing more than a single property to the blend in which they are used. Thus when employing a multifunctional additive component in the compositions of this invention, the amount used should of course be sufficient to achieve the function(s) and result(s) desired therefrom.

For some applications the finished oleaginous lubricant or functional fluid compositions of this invention are provided in ashless or low-ash form, i.e., the compositions in these cases either contain no added metalcontaining additive (and thus are "ashless") or they contain at most 100 ppm of metal in the form of metal- containing additive(s). In this connection, boron, phosphorus and certain other nonmetallic elements may form ash-like residues on parts exposed to extremely high temperatures or combustion processes. However such non- metallic additives are classified as "ashless" additives and thus can be present in any suitable amounts without detracting from the ashless or low-ash characterization of the composition.

Performance In order to illustrate the excellent performance achievable by the practice of this invention, low temperature viscosity tests were carried out in which detenninations of Brook[ield viscosities at -40. C were made in accordance with ASTM test method D 2983. The compositions tested and the results in terms of Brookfield viscosities at -40 C -5 are summari d in the following tables. In each case the additive concentrate (MIPaX) used was that of Example H, and the -40 0 Viscosity is the Brookfield viscosity as measured after maintaining the compositions in the bath at - 40 C for 16 hours.

Table 1

Components Run 1; Amounts Run 2; Amounts 1 Run 3; Amounts Used, wt Used, wt % Used, wt % a) Exxon 1365 10ON oil 89.90 79.90 84.40 b) ETHYLFLO 162 PAO None 10.00 10.00 c) ACRYLOrD 1263 V11 430 4.50 None d) DI-Pack 5.60 5.60 5.60 -40 Viscosity 31,W -13,530 176 is It will be seen from Table I that Run 2, which used a preferred composition of this invention, had a Brookfield viscosity at -40 6 C below 20,000 cP whereas the comparative compositions wherein the combination of components a), b) and c) was not 2 0 employed failed to reach this required low temperature viscosity.

Table II

Components Run 4; Amounts Run S; Amounts Run 3; Amounts Used, wt % Used, wt % Used, wt % a) Exxon 1365 10ON oil 89.90 79.90 84.40 b) ETHYLFLO 162 PAO None 10.00 10.00 c) Texaco TLA 5010 VIII 4.50 4.50 None d) DI-Pack 5.60 5.60 5.60 -40 Viscosity 36,750 --T-15,700 176,000 The data in Table H demonstrate that the composition of this invention (Run 5) wherein component c) was another preferred type of acrylic-type viscosity index improver exhibited much better low temperature performance than either of the comparative compositions. Moreover, neither comparative composition achieved a Brookfield viscosity equal to or below the required value of 20,000 cP at -40 C

Table IR

Components Run 1; Amounts Run 6; Amounts Run 7; Amounts Used, wt % Used, wt % Used, wt % a) Exxon 1365 10ON oil 89.90 69.90 74.40 b) ETHYLFLO 162 PAO None 20.00 20.00 c) ACRYLOID 1263 VH 4-50 4.50 None d) DI-Pack 5.60 5.60 5.6 sity 31,125 6,950 20 The data set forth in Table 1H further illustrate the synergistic results made possible by the practice of this invention. Thus, a preferred composition of the invention (Run 6) had a Brookfield viscosity far below the required value of 20,000 cP at -40 C

52 In fact, the Brookfield viscosity of this composition at -40 C was also far below the forthcoming DEXRONO-M requirement of 15,000 cP or less at 40 C. In contrast, neither of the comparative compositions used in Runs 1 and 7 achieved a Brookfield viscosity equal to or below 20,000 cP at -40 C.

Table IV

Components Run 8; Amounts Run 9; Amounts Run 7; Amounts j Used, wt % Used, wt % Used, wt % a) Exxon 1365 10ON oil 93.40 83.40 74.40 b) ETHYLFLO 162 PAO None 10.00 20.00 c) ACRYLOID 1263 VH 1.00 1.00 None d) DI-Pack 5.60 5.60 5.60 L-40. Viscosity 40,375 13,750 20,425 Table IV shows that the synergistic results achievable by the practice of this invention were obtained using as little as 1% (approximately 0.4% of active ingredient) of the acrylic-type viscosity index improver.

Table V

CO onents Run 10 Amounts Run 11 Amounts Run 7; Amounts 1 Used, wt % Used, wt % Used, wt % a) Exxon 1365 10ON oil 93.90 83.90 74.40 b) ETHYLFLO 162 PAO None 10.00 20.00 c) ACRYLOID 1263 VII 0.50 0.50 None d) DI-Pack 5.60 5.60 5.60 ity 44,475 14,630 20,4 It will be seen from Table V that synergistic results were achieved with as 53 little as 0_5% (approximately 0.2% of active ingredient) of the acrylic- type viscosity index improver.

Table VI

Components Run 12 Amounts Run 13 Amounts Run 7; Amounts Used, wt % Used, wt % Used, wt % a) Exxon 1365 10ON oil 94.30 84.30 74.40 b) ETRYLFM 162 PAO None 10.00 20.00 c) ACRYLOED 1263 VH 0.10 0.10 None DI-Pack 5.60 5.60 5.60 [410.:Vcosity 106,625 19,730 201425 The data of Table VI show that even with as little as 0.1% (approximately 0.0.4% of active ingredient) of the acrylic-type viscosity index improver, the synergistic 15 results made possible by the practice of this invention were achieved.

Similar synergistic results were obtained using 3% Acryloid 1263 VH and 5% Acryloid. 1263 VII with 10% of ETHYLFLO 162 oligomer in the same base oil and with the same DI-Pack as used in the foregoing tests. The Brookfield viscosities at -40 C were 13,625 and 13,900 cP, respectively.

Another composition of this invention was formed by blending together Exxon 1365 100 Neutral oil (74.9%), ETRYUL0 164 poly-a-olefin oligomer (15.0%), ACRYLOIDII 1263 VI improver (4.5%), and the DI-Pack of Example H (5.6%). The resultant composition had a Brookfield viscosity at -40 C of 17,280 cP.

54

Claims

1. An oleaginous composition which comprises (a) a major amount of mineral oil in the range of 75N to 200 N; and minor amounts of (b). polyma-olefin oligomer having a kinematic viscosity in the range of 2-7 cSt at 100 C and formed by a process comprising ofigonierizing at least one 1-alkene having 6-20 carbons in the molecule and (c) an oil-soluble acrylic polymeric viscosity index improver; with the proviso that said composition has a Brookfield viscosity <20,000 cP at -40 @C.

2. A composition as claimed in claim 1 having a Brookfield viscosity:515, 000 cP at -40 C.

3. A composition as claimed in claim 1 wherein said poly-a-olefin ongomer is hydrogenated poly-a-olefin oligomer.

4. A composition as claimed in claim 3 wherein said poly-a-olefin oligomer is a hydrogenated poly-a-olefin oligomer formed from 1-decene.

is

5. A composition as claimed in any of the preceding claims wherein said polymeric viscosity index improver is incorporated into said composition in the form of a solution of acrylic polymeric viscosity index improver in a hydrocarbonaceous solvent, which solution has a bulk viscosity in the range of 600-1200 cSt at 100 C.

6. A composition as claimed in claim 5 wherein said polymeric viscosity index improver is incorporated into said composition in the form of a solution composed of 3045 wt % of acrylic polymeric viscosity index improver dissolved in 55-70 wt % of a hydrocarbonaceous solvent, which solution has a bulk viscosity of 600-800 cSt at 100 0 C.

7. A composition as claimed in claim 5 wherein said polymeric viscosity index improver is incorporated into said composition in the form of a solution composed of 20- 65 wt % of acrylic polymeric viscosity index improver dissolved in 35-80 wt % of a hydrocarbonaceous solvent, which solution has a bulk viscosity of 800-1200 cSt at 100 C.

8. A composition as claimed in any of claims 1 to 4 wherein said polymeric viscosity index improver is incorporated into said composition in the form of a solution having a nominal bulk viscosity of 1000 cSt at 1000C and a specific gravity of about 0.905 and comprised of 4-10.99% polymerized n-butyl methacrylate, 1-3.99% polymerized dimethylaminopropylmethacrylamide, and 2034.99% of severely solventrefined hydrotreated light naphthenic petroleum distillates and 11-19.99% of severely- refined hydrotreated heavy naphthenic petroleum distillates.

9. A composition as claimed in claim 1 wherein said poly-a-olefin oligomer is a hydrogenated poly-a-olefin oligomer formed from 1-decene; said polymeric viscosity index improver is incorporated into said composition in the form of a solution of acrylic polymeric viscosity index improver in a hydrocarbonaceous solvent, which solution has a bulk viscosity in the range of 600-1200 cSt at 100'C; and said composition contains an additive package.

10. A composition as claimed in claim 9 wherein the Brookfield viscosity of said composition is:515,000 cP at - 40 C.

11. A composition as claimed in claim 1 substantially as hereinbefore described.

- 56