US3150157A - Fatty acid and naphthenic acid acylated borates - Google Patents

Description

United States Patent This invention relates to organic boron Compounds which may find use as additives for liquid hydrocarbon stocks such as motor fuels, i.e., gasoline or jet fuel, fuel oils, and lubricating oils. More particularly, the invention relates to borated, mon oacylated trimethylol alkarles and to their use as motor fuel additives.

It is Well known that during the operation of an initially clean internal combustion engine running on a hydrocarbon fuel, deposits gradually build up on the surfaces of the engines combustion chamber. The adverse effect of such deposits manifests itself in uncontrolled ignition and a general lack of smoothness in engine operation, caused principally by the deposits on the combustion chamber surfacesbecoming heated to incandescence during engine operation, and igniting the fuel either before or after that portion of the cycle Where normal spark plug discharge Would cause ignition. This phenomenon is commonly referred to as surface ignition.

The deposit problem is aggravated by 'the presence in the fuel of a tetra-alkyl lead anti-knock compound, because the deposits are then no longer essentially carbonaceous, but contain appreciable quantities of lead and lead compounds in admixture with carbonaceous material. These mixed deposits are more tenacious and troublesome than a pure carbonaceous deposit, despite the fact that one or more organic halide may be present in fuel as lead scavenging agents.

It has been found that the incorporation of minor amounts of the organic boron compounds of this invention to motor fuels in some manner modifies the nature of the combustion chamber deposits formed, so as to decrease the incidence of surface ignition.

Deposits are also known to build up on the surfaces of carburetor internals, viz., carburetor Walls, throttle valve, jets, and venturi. Such deposits are believed to accumu late from contaminants borne by the copious quantities of intake air an operating carburetor breathes. The situation is aggravated by prolonged engine operation in I RI! where R is an allcyl group having from 1 to 6 carbon atoms; R and R are selected from the group consisting of a hydrogen atom and an alkyl radical having from 1 to 3 carbon atom; and R and R" may be the same or different in the compound; R is selected from the group consistihg of alkyl arid alkenyl radicals haviiig from 7 to 20 carbon atoms, and naphthenyl radicals having from 10 to 20 carbon atoms; and X is selected from the group consisting of hydrogen and R! a I 0110,11

where R, R, R", and R are defined the same as above.

The bo'ron compounds of this invention may be prepared by (l) refluxing in the presence of a solvent equimola'r portions of a trialkylol alkane and a carboxylic acid, until the theoretical amount 'of Water to form the moho-acylated intermediate is removed az'eotropically; and (2) bo'ra'tin'g the mono-acylat'e'd intermediate with a s toicli i'ornetric amount of bofic oxide or horic acid and again removing the vi'ater of reaction by azeotrop'ic distillation. v

The two-step reaction is believed to proceed according to the following representations:

where R, R, R and R are defined thesam'e as above, lln connection With the borating step, an additional molecule of Water may be removed by azeotropic distillation to form the borate anhydride:

Br! R 0H0 where R, R, R" and R' are definedthe same as above.

The reactions may be carried out in the presence of any suitable organic solvent, such as benzene, xylenes, toluene, catalytic reformate, neutral oil and the like. Preferred solvents are those which are normally found in the petroleum product (be it a motor fuel or fuel oil or a lubricating oil) to which the boron compound is to be added. If the solvent does not form an azeotrope with water, enough of an azeotropic forming agent is included to remove the water azeotropically.

Example I.--B0rated, Oleated Trimethylol Propane (1) 201 grams of a trimethylol propane and 423 grams of oleic acid (a 1:1 molar ratio) were mixed together in 300 ml. of xylenes. The mixture was heated with stirring at reflux until 27 m1. of water (the theoretical amount to form the mono-acy1ated intermediate) were removed by azeotropic distillation.

(2) 478 grams of the mono-acylated intermediate and and 74.3 grams of boric acid (a 1:1 molar ratio) were mixed together in 240 ml. of xylenes. The mixture was heated with stirring at reflux until 54 ml. of water (the theoretical amount to form the borate anhydride) were removed by azeotropic distillation. Boron analysis of the resulting product showed 2.54% B, compared with 2.60% B theoretical.

Example II.B0rated, Nonanoated, Trimethylal Propane (1) 13.4 grams of trimethylol propane and 15.9 grams of nonanoic acid (a 1:1 molar ratio) were mixed together in 500 ml. of xylenes. The mixture was heated with stirring at reflux until 1.8 ml. of water (the theoretical amount to form the mono-acylated intermediate) were removed by azeotropic distillation.

(2) 27.5 grams of the mono-acylated intermediate and 6.2 grams of boric acid (a 1:1 molar ratio) were mixed together in 500 ml. of xylenes. The mixture was heated with stirring at reflux until 4.5 ml. of water (the theoretical amount to form the borate anhydride) were removed by azeotropic distillation.

Boron analysis of the resulting product showed 3.7% B, identical to theoretical.

Example lII.Borated, Laurolated Trimethylol Ethane (1) 12.2 grams of trimethylol ethane and 200 grams of lauric acid (a 1:1 molar ratio) were mixed together in 200 ml. of xylenes. The mixture was heated with stirring at reflux until 18 ml. of water (the theoretical amount to form the mono-acylated intermediate) were removed by azeotropic distillation.

(2) 152 grams of the mono-acylated intermediate and 31 grams of boric acid (a 1:1 molar ratio) were mixed together in 100 ml. of xylenes. The mixture was heated with stirring at reflux until 22.5 ml. of water (the theoretical amount to form the borate anhydride) were removed by azeotropic distillation. Boron analysis of the resulting product showed 3.03% B, compared with 2.81% B theoretical.

Example IV.-B0rated, Nonanoated Trimethylol Ethane (1) 12.2 grams of trimethylol ethane and 158.5 grams of nonanoic acid (a 1:1 molar ratio) were mixed together in 250 ml. of xylenes. The mixture was heated with Stirring at reflux until 18 ml. of water (the theoretical amount to form the monoacylated intermediate) were removed by azeotropic distillation.

(2) 197 grams of the mono-acylated intermediate and 46.3 grams of boric acid (a 1:1 molar ratio) were mixed together in 187.5 ml. of xylenes. The mixture was heated with stirring at reflux until 33.7 ml. of water (the theoretical amount to form the borate anhydride) was removed by azeotropic distillation.

It will be understood that mixtures of fatty acids may also be used in the above preparations. Commercially available mixtures include those derived from tallow and naturally occurring oils, such as cottonseed oil, soybean oil, coconut oil, tall oil and the like.

Example V.-B0rated, Naphthenated T rimethylol Ethane Since pure naphthenic acids are not readily available, a mixture of naphthenic acids was used in the following preparation. The mixture used was Eastmans yellow label (practical grade) naphthenic acids having a boiling point range of 160-l98 C./ 6 mm. and an average molecular Weight of 230.

(1) 134 grams of trimethylol propane and 230 grams of naphthenic acids (an approximated 1:1 molar ratio based on the average molecular weight of the naphthenic' was removed by azeotropic distillation, to form the borate l anhydride.

The reaction can similarly be carried out with a,a'-dimethyl trimethylol propane, oa,oc'-biS isopropyl trimethylol hexane, a,a-diethyl trimethylol pentane, a,a-dibutyl trimethylol heptane, a-ethyl, a-isopropyl trimethylol ethane and the like.

Gasoline base stocks to which the organic boron compounds of this invention can be added are any of those conventionally used in preparing a motor gasoline for a spark-ignited internal combustion engine; such as catalytic distillate, motor polymer, alkylate, catalytic reformate, isomerate, naphthas, etc. The gasoline will preferably contain a tetra-alkyl lead compound as an anti-knock agent, and a scavenging agent. The amount of the antiknock agent will be usually at a level of approximately 3 ml./gal., but may range from /2 ml./gal. up to 6 mL/gal. The base gasoline may also include other common additives such. as anti-oxidants, stabilizers, solvent oils, dyes, and the like. i

The amount of organic boron compound to be added to gasoline to accomplish the purposes of this invention may vary, and is conveniently expressed in terms of percentrby weight of boron. Excellent results have been obtained where the amount of compound is within the range of .0005 to .008% boron by weight. Usually amounts greater than .1% boron by weight cannot be economically justified. The compounds may be added directly to the gasoline, or as previously noted, they may be added in the form of a liquid concentrate in the solvent used in their preparation, provided said solvent is compatible with the gasoline.

rIt is to be understood that various modifications of the present invention will occur to those skilled in the art upon reading the foregoing disclosure. It is intended that all such modifications be covered which reasonably fall within the scope of the appended claim.

This application is a division of application Serial No. 93,348 filed March 6, 1961.

where R is an alkyl group having from 1 to 6 carbon 10 atoms; R and R are selected from the group consisting of a hydrogen atom and an alkyl radical having from 1 to 3 carbon atoms; R is selected from the group consisting of alkyl and alkenyl radicals having from 7 to 20 carbon atoms and naphthenyl radicals having from 10 to 20 carbon atoms; and X is selected from the group consisting of hydrogen and where R, R and R and R are defined the same as above.

No references cited.