CA1092297A - Flexible polyurethane foams - Google Patents
Flexible polyurethane foamsInfo
- Publication number
- CA1092297A CA1092297A CA249,596A CA249596A CA1092297A CA 1092297 A CA1092297 A CA 1092297A CA 249596 A CA249596 A CA 249596A CA 1092297 A CA1092297 A CA 1092297A
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- CA
- Canada
- Prior art keywords
- crosslinking agent
- catalyst
- examples
- amine salt
- carboxylic acid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/30—Low-molecular-weight compounds
- C08G18/32—Polyhydroxy compounds; Polyamines; Hydroxyamines
- C08G18/3225—Polyamines
- C08G18/3253—Polyamines being in latent form
- C08G18/3259—Reaction products of polyamines with inorganic or organic acids or derivatives thereof other than metallic salts
- C08G18/3262—Reaction products of polyamines with inorganic or organic acids or derivatives thereof other than metallic salts with carboxylic acids or derivatives thereof
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/65—Low-molecular-weight compounds having active hydrogen with high-molecular-weight compounds having active hydrogen
- C08G18/66—Compounds of groups C08G18/42, C08G18/48, or C08G18/52
- C08G18/6666—Compounds of group C08G18/48 or C08G18/52
- C08G18/667—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38
- C08G18/6681—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/32 or C08G18/3271 and/or polyamines of C08G18/38
- C08G18/6685—Compounds of group C08G18/48 or C08G18/52 with compounds of group C08G18/32 or polyamines of C08G18/38 with compounds of group C08G18/32 or C08G18/3271 and/or polyamines of C08G18/38 with compounds of group C08G18/3225 or polyamines of C08G18/38
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Polyurethanes Or Polyureas (AREA)
Abstract
A B S T R A C T
This invention relates to a process for producing polyurethane foam having improved load bearing properties.
The process comprises reacting in one step a polyether and a crosslinking agent with a polyisocyanate in the presence of a catalyst and a blowing agent. At least a portion of the crosslinking agent is a soluble amine salt obtained by reacting a polyamine having at least two primary groups with a carboxylic acid. Applications of this invention are in the manufacture of cushioning for furniture and automotive industries.
This invention relates to a process for producing polyurethane foam having improved load bearing properties.
The process comprises reacting in one step a polyether and a crosslinking agent with a polyisocyanate in the presence of a catalyst and a blowing agent. At least a portion of the crosslinking agent is a soluble amine salt obtained by reacting a polyamine having at least two primary groups with a carboxylic acid. Applications of this invention are in the manufacture of cushioning for furniture and automotive industries.
Description
1092Zg7 It has now been found that polyurethane ~oam prepared by reacting in one step a polyether polyol and a crossiinking agent with a polyisocyanate in the presence of a catalyst and a blowing agent has improved load bearing properties when a soluble amlne salt obtained by reacting a cycloaliphatic polyamine having at least two prlmary amine groups wlth approximately the stoichiometric equivalen~ amount of a carboxylic acid is employed as at least a portion of the crossllnking agent.
While the invention is not predicated on theory, it is believed that the amine salt acts as a latent crosslinking agent. Instead of primary amine groups reacting preferentially with the isocyanate groups early in the reaction, the amine-isocyanate reaction is delayed until the heat of the reaction causes the amine salt to dissociate. The delayed reaction allows the crosslinking to take place in the latter stages of the reaction. Poly-urethane foam recipes containing the amine salt give foams characterized by improved load bearing properties, such as compression and indentation load deflection.
The process according to the invention will now be described in more detail with respect to preparation of polyurethane foams by reacting as essential ingredients (A) crosslinking agent, (B) polyether polyol, (C) polyisocyanate, (D) catalyst, and (E) blowing agent. Optionally, one or more cell control agents may be utilized. Other agents, optionally used in the ,-production of polyurethane foams, may also be included for special desired effects. --1- , ...
l~9 Z Z 9 7 The special crosslinking agents of the present invention are soluble amine sal~s obtained by reacting a cycloaliphatic polyamine having at least two primar~ amine groups with a carboxylic acid, The amine salt is soluble either in the polyol component or in water, In addition to carbon, hydrogen and nitrogen, suitable amines may optionally contain elements such as, for example, oxygen, sulfur, and halogens. Examples of cycloaliphatic amines include 1,3-diaminocyclohexane and aminocyclohexanemethanamines such as, for example, menthanediamine (4-amino-o~a,-4-trimethylcyclohexane-methanamine) and isophoronediamine (5-amino-1,3,3-trimethylcyclohexane-methanamine) Preferably the polyamine is an aminocyciohexanemethanamine.
More preferably the polyamine is isophoronediamine.
In addition to carbon, hydrogen, and oxygen~ suitable carboxylicacids may optionally contain elements such as, for example, nitrogen, sulfur, and :-.,. ;, lO9X:97 halogens. Suitable acids include aliphatic and aromatic mono- and polycarboxylic acids having a melting point above 25C. Examples of aliphatic acids include oxalic, malonic acid, maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and tricarballyic acid.
Examples of aromatic acids include benzoic and phthalic acid. Advantageously the carboxylic acid contains from two to thirty carbon atoms, preferably three to ten carbon atoms. More preferably the carboxylic acid i8 an aliphatic dicarboxylic acid containing from four to six carbon atoms. Most preferably the carboxylic acid is succinic acid, adipic acid or mixtures thereof.
The amine salt is preferably prepared as an aqueous solution by dissolving the amine in water and adding approximately the stoichiometric equivalent amount of acid. As water is usually metered into the mixing chamber of a foam head, it is preferable to prepare the aqueous amine salt solution at a concentration - such that each unit volume of solution contains the required amount of water and amine salt. This aqueous - -stream may also contain other components such as, for example, catalyst, cell control agent or additional crosslinking agents. The invention is not based upon -a specific concentration range for use of the amine salt crosslinking agent. Generally they are employed - in amounts from 0.1 to 10 parts by weight per 100 ~ -parts of polyol. optimum concentrations will vary depending upon the choice of polyamine and carboxylic acid. optimum results for the isophoronediamine--succinic acid salt and the isophoronediamine-adipic 1/,708-F -3-,: :, lOgzz ~
acid salt are obtained when they are employed in the range of 3 to 5 parts by weight per 100 parts of polyol.
As a preferred embodiment, one or more auxili-S ary crosslinking agents kr.own in the art are added to the foaming formulation with the amine salt crosslink-ing agent. Auxiliary crosslinking agents include low molecular weight amines and hydro~yl containing compounds such as, for example, tris(polyoxyalkylene alkanol)amines;
mono-, di-, and tri-ethanolamines; mono-, di-, and tri-iso-propanolamines; oxyhydrocarbon or oxyhydrocarboxy deriva-tives of isocyanuric acid or aryl substituted isocyanuric acid; oxydianiline; an aliphatic diol or a polyether diol having an hydroxy equivalent weight less than 300 and preferably less than 200; and aliphatic, alicyclic and aromatic polyamines having from 1 to about 30 carbon atoms. Advantageously the auxiliary crosslinking agent is the same polyamine as that used to prepare the amine salt. Auxiliary crosslinking agents are generally em-ployed in the range from 0.1 to 5 parts by weight per 100 parts of polyol.
Suitable polyether polyols are obtained by reacting an alkylene oxide such as, for example, ethylene oxide, propylene oxide, butylene oxide or ~5 a mixture of two or more thereof, with an initiator having a multiplicity of active hydrogen atoms such as, for example, alkylene glycols, glycerol, trimethyl-ol propane, pentaerythritol, sorbitol, hexane triol, sucrose, ethylenediamine, polyalkylenepolyamines, phenol-aldehyde condensates, bi~phenol A, or a mixture 1/,708-F ~4~
1092Z~7 of two or more thereof. Polyether polyols derived from propylene oxide or a mixture of propylene oxide and ethyl- -ene oxide either contain only secondary hydroxyl groups or a mixture of secondary and primary hydroxyl groups.
S By reacting these polyols with ethylene oxide one can obtain modified polyols having a high primary hydroxyl content. These modified polyols are described as "cappedn or "tipped" polyether polyols and can be used with advantage -- -in the process according to the invention. Suitable polyether polyols have a number average molecular weight range from 200 to 7000, preferably 3000 to 7000. Suitable polyols preferably have a hydroxyl number range from 24 to 56.
In preparing the polyurethane foams of the -present invention, any of a wide variety of polyiso- ---cyanates may be employed either alone, as isomer mixtures, or as mixtures of different polyisocyanates.
Aromatic, aliphatic and alicyclic diisocyanates and combinations of these types are useful. Representa- ~-tive polyisocyanates include 2,4-toluenediisocyanate (TDI), 2-6-toluenediisocyanate, methylene-bis~p-phenyliso- -cyanate) t polymethylene polyphenylisocyanates, crude -~
or undistilled isocyanates, dimers or trimers of poly-isocyanates and prepolymers made by the reaction of a stoichiometric excess of such isocyanates with any of the above mentioned polyether polyols or with other compounds having sites reactive with isocyanates.
Arylene diisocyanates, i.e. those in which each of the two isocyanate groups is attached directly to an aromatic ring, are preferred.
17,708-F ~5-~ . .
Catalyst systems employed include, for example, tertiary amine catalysts such as triethylenediamine, dimethylethanolamine, bis-2(N,N-dimethylaminoethyl) ether, and N-ethylmorpholine, which catalyze the water-isocyanate reaction as well as the hydroxyl--isocyanate reaction and the usual organo-tin cata-lysts including stannous octoate. When the process of the invention is used to produce molded flexible poly-urethane foam, usually organo-tin catalysts are not incorporated into the foaming formulation. When the process of the invention is used to produce slab stock flexible polyurethane foams, usually organo-tin cata-lysts are incorporated into the foaming formulation.
Sufficient catalyst is used to produce desired foaming parameters such as, for example, cream time and rise time. The optimum concentration of the catalyst system for a given foaming formulation is determined by incrementally adjusting the concentration until the desired conditions are met.
The density of the foam is varied by using different proportions of a blowing agent. In addi-tion to reasons of commercial considerations, water is the most convenient blowing agent to employ. Water offers an additional advantage as a blowing agent in that it not only undergoes an in situ reaction with the isocyanate group to produce carbon dioxide but also results in urea linkages which serve as crosslinking sites. Other blowing agents which may be employed include methylene chloride and fluorocarbons.
17,708-F -6-', 109~7 Co~mon cell control agents which may be optionally incorporated in the foaming formulation are exemplifled by sliicone surfactants, such as, for example, siloxane-gl~col copolymersJ which are employed to generally -improve the miscibllity of the components and aid in controlling the size of the cells in the foam. In the case of high resiliency foams, polydimethyl-siloxyanes, polyphenylmethylsiloxanes, or low activity polyoxyalkylene-polydimethylsiloxane block copolymers are employed to produce foams with a high proportion of open cells, The polyurethane foams according to the invention can be made by prepolymer, semi-prepolymer and one-shot foam techniques.
Such techniques are well known to those skilled in the art and can be varied depe~ding upon the type of product desired.
In order that the invention be well understood, the following examples are given by way of illustration only. Foam properties were measured according to ASTM D-1564 and D-2406. -Examples of high resilient cold cure polyurethane foams using isophoronediamine-succinic acid amine salt crosslinking agent and isophorone-diamine as the auxiliary crosslinking agent and diethanolamine as an auxiliary crosslinking agent were compared with high resilient foams using Amine 70 as the crosslinking agent. An aqueous solution of the amine salt, hereinafter known as Amine Salt A, was prepared by dissolving isophoronediamine in water and then adding the stoichiometric equivalent amount of succinic acid.
B
. . .
- , , ;: , .. . ..
lO9ZZ~7 Additional isophoronediamine, hereinafter known as Auxiliary Crosslinking Agent E, and diethanolamine, hereinafter known as Auxiliary Crosslinking Agent F were added to the amine salt solu~ion. The proportions of amine, carboxylic acid and water were equivalent to those desired for the foaming formulation. For Comparative Runs A and B, Amine 70, hereinafter known as Amine Crosslinking Agent C, was dissolved in water in proportions needed for the foaming formulations. Amine 70 is a still bottom product obtained in the reaction of ethylenediamine with ethylene oxide. The polyol used in Examples 1 and 2 and Comparative Runs A and B, hereinafter known as Polyol G, was a commercial polyether triol made by reacting glycerol with propylene oxide and end capping with ethylene oxide. Polyol G has an hydroxyl equivalent weight of 1570 and contains 60 to 80% primary hydroxyl groups. The poly- -isocyanate used, hereinafter known as Polyisocyanate I, was an 80/20 mixture of 2,4-/2,6-toluenediisocyanate having an isocyanate equivalent weight of 87.
A solution containing 33 weight percent triethylenediamine in dipropylene glycol, hereinafter known as Catalyst K, was used as a catalyst in both examples and both comparative runs. Dimethylethanolamine, hereinafter known as Catalyst L, and stannous octoate, hereinafter known as Catalyst P, were additionally used in Comparative Runs A and B. A polydimethylsiloxane, here-inafter known as Cell Control Agent Q, having a molecular weight of a~out 900 and diluted in a ratio of 1:9 with an isobutyrate plasticizer, was used in both examples and both comparative runs.
.B -8-.. . .
-~ 109Z~97 In each of the examples the aqueous solution of the amine salt crosslinking agent~ the auxiliary crosslinking agent, the polyol, the - catalyst and the cell control agent were blended together until the components were equally dispersed. Then the polyisocyanate was added and the foaming formulation stirred for several more seconds. The foaming formulation was then poured into an open container and allowed to rise. The foam was cured at room temperature for 36 hours before testing. Densities of the foams were varied by varying the amounts of water and isocyanate. The formulations, foam conditions and foam properties are shown in Table I.
Examples of the invention showed an improvement in tensile strength, tear resistance, 40% compression load deflection (CLD), and CLD
: ~odulus 65/25 over the comparative runs. The improvement in 40% CLD ranged from 48 percent to 67 percent when comparing foams of similar densities. It should be noted that the examples required a larger proportion of Catalyst K
than the comparative runs.
TABLE I
Formulation (parts by weight) 1 2 A B
Amine Salt Crosslinking Agent A 3.6 3.6 Amine Crosslinking Agent C --- --- 2.0 2.0 Auxiliary Crosslinking Agent E 0.4 0.4 --- ---Crosslinking Agent F 0.5 0.1 --- ---Polyol G lO0 lO0 lO0 lO0 Polyisocyanate I 30.5 36.530.0 35.0 Catalyst K 1.25 1.1 0.3 0.3 Catalyst L --- --_ 0.5 0.4 ~B -9- :
, . . .
TABLE I ~Continued) Formulation (parts b weight) 1 2 A B
~ Y . . _ . _ . . _ Catalyst P --- --- 0.15 0 25 Cell Control Agent Q 0.1 0.1 0.1 0.1 Wa~er 2.0 2.5 2.0 2.5 Foam Conditions Cream Time, seconds 10 9 6 6 Rise Time, seconds 135 130 110 105 Foam Pro erties p Density, kg/m3 39 0 34.540.0 35.0 Tensile Strength, kg/cm2 1.1 1.00.80 0.75 Elongation, % 160 155 180 170 Tear Resistance, kg/cm 0.55 0.50 0.4 0.4 Resilience, % 62 62 66 66 40% CLD, g/cm 34 30 23 18 Hysteresis, % 21 22 18 19 CLD Modulus 65/25 3.1 3.0 2.7 2.7 Examples 3-7 and Comparative Runs C and D illustrate molded foams prepared from hand mixed formulations. The foaming formulations were -prepared as described in Examples 1 and 2 and Comparative Runs A and B. Amine -~Salt Crosslinking Agent A and Auxiliary Crosslinking Agent E were also used in Examples 3-7 in the same manner as Examples 1 and 2. Additional Auxiliary Crosslinking Agent F was added to the foaming formulations of the Examples. -Comparative Run C employed an amine crosslinker which is diisopropanolamine, hereinafter known as Amine Crosslinking Agent D. Comparative Run D did not employ an amine crosslinking agent and neither Comparative Run ' ~
B -lo-. . .
~, . ,. ~ , . ., ; ~ . , ,. "
lO~
C or D employed an auxiliary crosslinking agent. The polyether polyol used for Examples 3-7 and Comparative Runs C and D, hereinafter knbwn as Polyol H, is a commercial polyether triol made by reacting glycerol with propylene oxide and ethylene oxide and end capping with ethylene oxide Polyol H has a hydroxyl equivalent weight of 1570 and contains 60 to 80 percent primary hydroxyl groups. Polyisocyanate I was used for Examples 3-7. Comparative Runs C and D employed a polyisocyanate which was a solution of trimerized TDI in 80% (2,4-)-20% (2,6-) TDI, hereinafter known as Polyisocyanate J.
Catalyst K was used for Examples 3-7 and Comparative Runs C and D. Catalyst L was used for Comparative Runs C and D. For Examples 3-7, additionally bis-2(N,N-dimethylaminoethyl)ether, hereinafter known as Catalyst M, was added. For Comparative Runs C and D, addition-ally N-ethyl morpholine, hereinafter known as Catalyst N, was added.
Examples 3-7 contained Cell Control Agent Q, while Comparative Runs C and D contained a phenylmethylsiloxane, hereinafter known as Cell Control Agent R.
After mixing of the components was completed, each foaming formulation was poured into a 10 x 35 x 35 centimeter aluminum mold heated to 45-50C. Each foam sample was removed after 10 minutes -in the mold. Formulations, foam conditions and foam properties are shown in Table II. -Examples 3-7 have higher resilience, lower hysteresis loss ~ -and equal or higher CLD Modulus 65/25 than Comparative Runs C and -D. The high 40~ CLD of Comparative Run C was obtained by employing a premium '' .
10922g7 amine crosslinking agent not in wide-spread use because of its cost, as well as a special polyisocyanate and a special cell control agent which are higher cos~ components when compared with the corresponding components of Examples 3-7. Example 4 had the same density as Comparative Run D, The improved resilience and CLD Modulus 65/25 and lower hysteresis loss are accomplished with lower cost components than Comparative Run D.
High resiliency flexible polyurethane foam employing styrene acrylonitrile copolymer polyols had load bearing characteristics similar to Comparative Run D, when measured on foams having the same density. Polyisocyanate J employed in Comparative Runs C and D and the copolymer polyols require special storage conditions to prevent contamination of other materials.
T~BLE II
Formulations (parts by weight) 3 4 5 6 7 C D
-Amine Salt Cross- 3.9 4.9 3.9 3.2 3.9 --- ---linking Agent A
Amine Crosslinking --- --- --- --- --- 2.0 ---Agent D
Auxiliary Cross- 0.7 0.1 0.7 1.1 0.7 --- ---linking Agent E
Auxiliary Cross- 0.75 1.0 0.75 0.5 0.75 --- - ---linking Agent F
Polyol H 100 100 100 100 100 100 100 Polyisocyanate I 41.5 42.0 41.5 36.0 36.5 --- ---Polyisocyanate J --- --- --- --- --- 49.0 46.0 Catalyst ~1.25 1.25 1.25 1.01.25 0.3 0.4 Catalyst L --- --- --- --- --- 0.5 0.5 Catalyst M0,15 0.15 0.20 1.15 0.15 -' 10~
TABLE II ~Cont.) Formulations (parts by wei~ht) 3 4 5 6 7 C D
_ Catalyst N ~ - --- --- 0-5 0-5 Cell Control Agent Q 0.1 0.1 0.05 0.1 0.1 --- ---Cell Control Agent R --- --- --- --- --- 1.0 1.0 Water 3.0 3.0 3.0 2.5 2.5 3.1 3.1 Foam Conditions Cream Time, Seconds 9 8 9 8 8 6 6 Rise Time, Seconds 90 95 90 85 90 90 95 Foam Pro erties P
Density, kg/m3 42 42 42 50 49.5 46 42 Tensile Strength,kg/cm2 1.1 0.9 1.1 1.3 1.2 1.2 1.2 -Elongation, %165 140 135 165 155 135 155 Tear Resistance, kg/cm 0.5 0.5 0.5 0.5 0.5 0.6 0.6 -Resilience, % 63 62 62 62 62 58 57 40% CLD, g/cm2 30.5 33 32 36 37.5 36.5 30.5 Hysteresis, % 20 21 22 19 20 27 25 CLD Modulus 65/25 3.0 3.1 3.1 3.3 3.1 3.0 3.0 Examples 8-15 illustrate high resiliency flexible slab stock polyurethane foams prepared on large scale produc~ion type foam machines. -~
Examples 8-14 employed a Viking foam head and Example 15 employed a Hennecke UBT foam head. The foaming formulations for all examples contained Auxiliary Crosslinking Agent E, Polyol H, Polyisocyanate I, Cell Control Agent Q, and stannous octoate, hereinafter known as Catalyst P. Examples 8-10 employed an aqueous solution of Amine Salt Crosslinking Agent A prepared ~09~g7 as described in Examples 1 and 2. Examples 11 and 15 employed an aqueous solution of an amine salt crosslinking agent prepared from isophoronediamine and adipic acid hereinafter known as Amine Salt Crosslinking Agent B, in the same manner as described for Amine Salt Crosslinking Agents A and B. Examples 12-14 employed both Amine Salt Crosslinking A&ents A and B. Examples 8-11 and 15 additionally employed a Catalyst M. Examples 12-14 additionally employed Catalyst L. Example 15 employed solid 100% triethylenediamine, hereinafter known as Catalyst 0. Formulations, foam conditions, and foam properties are shown in Table III.
TABLE III
Formulations (parts by wei~ht) 8 9 10 11 12 13 14 15 -Amine Salt Crosslinking Agent A 2.9 2.9 2.9 --- 2.4 2.42.4 Amine Salt Crosslinking Agent B --- --- --- 3.3 0.5 0.50.5 3.0 Auxiliary Crosslinking Agent E 0.6 0.6 0.61.2 0.6 0.60.6 1.0 Polyol H lO0 lO0 lO0lO0 lO0 lO0lO0 lO0 Poly-isocyanate I30 30 30 31 30 30 30 36 Catalyst K 0.4 0.4 0.40.75 0.75 0.750.75 ---Catalyst L --- --- --- --- 0.5 0.5 0.5 -__ Cstalyst M 0.2 0.2 0.20.2 --- --- --- 0.1 Catalyst 0 --- --- --- --- --- --- --- 0.3 Catalyst P0.25 0.2 0.150.2 0.25 0.20.15 0.3 B 14 _ ..
::
- tO~Z297 TABLE III (Cont.) Formulations (parts by wei~ht) 8 9 10 11 12 13 14 15 Cell Size Control ~gent Q 0 4 0.3 0.2 0.4 0.4 0.3 0.2 0.2 Water 2.0 2 0 2.0 2.0 2 0 2.0 2.0 2.5 Foam Conditions Polyol through- - -put, kg/min.12 12 12 12 12 12 12 50 Polyol/TDI
temp. C.20/20 20/20 20/20 20/20 20/2020/20 20/20 22/22 Stirrer, rpm 3600 3600 3600 3600 3600 3700 3700 3000 Air at 30 psi, l/min1 0 1,0 1.0 0.85 0.85 0.85 0.85 0.7 Conveyor ~.
Speed, m/min 1.6 1.5 1.5 1.7 1.6 1.6 1.6 3.1 Conveyor Angle, 5 5 5 5 5 5 5 5 Cream Time, seconds 9-10 --- --- 8 . 8 --- --- 7 ~ ~
Rise Time, :
seconds --- 140 --- --- --- 135 --- 135 Foam Properties -Density, ~ -kg/m3 42 42 41.5 39 41 41 40 36 Tensile Strength, kg/cm2 0.75 0.7 0.7 1.2 0.85 0.85 0.9 0.8 Elongation, % 145 130 120 250 170 180 160 160 -Tear Resistance, kg/cm 0.4 0.3 0.3 0.5 0.35 0.3 0.3 0.35 Resilience, % 61 62 60 59 59 60 61 61 Compression set, % 3 5 4 4 9 10 10 8 6 .
j lO9ZZ n TABLE III (Cont.) Formulations ~parts by wei~ht) 8 9 10 11 12 13 14 15 . . _ 40 %2CLD, g/cm 35 39 38 30.5 32 33.5 33.5 3~.5 ILD, lbs @25% 35.5 40 39 3033.5 33.5 34 32 Hysteresis,%22 22 22 22 22 22 22 22 CLD Modulus 65/25 2.75 2.82.75 2.92.8 2.8 2.8 2.7 There was no shrinkage in any of the foams after cure and the foams were easy to crush after three days. Combinations of catalysts were used at varying concentrations to illustrate in the examples that a variety of foaming formulations will produce flexible foams having commercially desirable properties. The amine salt crosslinking agents exhibited r.o catalytic effect of their own. Catalyst levels for the examples were higher than for the comparative runs. The variation in foam properties in general follows the expected pattern for one shot flexible polyurethane foams.
Examples of foaming formulations employing amine salt cross-linking agents in general exhibited longer cream times and rise times than for the comparative runs. This supports the concept that the amine salt crosslinking agent reacts later in the reaction when the heat of the reaction dissociates the amine salt. The amine salts did not have the characteristic odor of the amine. However, during the later stages of the foaming reaction, the characteristic odor was again -detected. This observation ~092297 also supports the concept of the amine ~alt as a latent crosslinking agent.
Examples 16 and 17 were aimed at proving u~e-fulness of amine salts for conventional flexible foams.
The polyol used in examples 16 - 17 and comparative runs E and F, hereinafter known as Polyol T, was a commercial polyether triol made by reacting glycerol with propylene oxide and ethylene oxide in a mixed feed. Polyol T has a hydroxyl equivalent weight of 1360.
The polyisocyanate used, hereinafter known as Polyisocyanate I, is an 80/20 mixture of 2,4-/2,6--toluenediisocyanate having an isocyanate equivalent weight of 87.
; Catalysts K, L, and M were used again as blowing catalysts. A polyoxyalkylenepolydimethylsiloxane co-polymer, hereinafter known as Cell Control Agent U was used in both examples and both comparative runs. Cata-lyst P, the polymerization catalyst, was also used for both examples and comparative runs.
In these examples the aqueous solution of the amine salt crosslinking agent, the auxiliary cross-linking agent, and the tertiary amine catalysts were mixed into the water stream. The stannous octoate cata-lyst and the silicone surfactant were mixed into the polyol.
While stirring the polyol side at a high speed, the water stream and the polyisocyanate were added simultaneously. Then the foaming formulation 17,708-F -17-~ . .
lO9Z297 was stirred to several more seconds. The foaming formulation was then poured into an open container and allowed to rise.
Densities of these foams were varied by varying the amounts of water and isocyanate. Formulations, foam conditions, and foam preperties are shown in Table IV.
TABLE IV
Formulation (parts ~ ht) 16 17 E F
Amine salt crosslinking agent A 3.6 3.6 Auxiliary crosslinking agent E 0.4 0.4 --- ---Polyol T100 100 100 100 Polyisocyanate I 42.5 52.5 40.5 50.5 Catalyst K --- --- 0.35 0.30 Catalyst L 0.5 0.5 -~
Catalyst M 0.15 0.12 --- ---Silicone surfactant U 0.70.8 0.7 0.8 Water 3.04.0 3.0 4.0 Catalyst P 0.100.10 0.125 0.125 Foam Conditions Cream time, seconds 10 10 8 8 Ri~e time, ~econds 115 100125 115 Foam properties Density kg/m 30.0 24.031.025.0 40% CLD g/cm2 33.0 30.533.030.0 CLD modulus 65/25 2.5 2.42.1 2.0 Examples of the invention show an improvement in CLD modulus 65!25 at same hardness over the compara-tive runs. Improvement in modulus was 20%.
i:
17,708-F -18- ~
While the invention is not predicated on theory, it is believed that the amine salt acts as a latent crosslinking agent. Instead of primary amine groups reacting preferentially with the isocyanate groups early in the reaction, the amine-isocyanate reaction is delayed until the heat of the reaction causes the amine salt to dissociate. The delayed reaction allows the crosslinking to take place in the latter stages of the reaction. Poly-urethane foam recipes containing the amine salt give foams characterized by improved load bearing properties, such as compression and indentation load deflection.
The process according to the invention will now be described in more detail with respect to preparation of polyurethane foams by reacting as essential ingredients (A) crosslinking agent, (B) polyether polyol, (C) polyisocyanate, (D) catalyst, and (E) blowing agent. Optionally, one or more cell control agents may be utilized. Other agents, optionally used in the ,-production of polyurethane foams, may also be included for special desired effects. --1- , ...
l~9 Z Z 9 7 The special crosslinking agents of the present invention are soluble amine sal~s obtained by reacting a cycloaliphatic polyamine having at least two primar~ amine groups with a carboxylic acid, The amine salt is soluble either in the polyol component or in water, In addition to carbon, hydrogen and nitrogen, suitable amines may optionally contain elements such as, for example, oxygen, sulfur, and halogens. Examples of cycloaliphatic amines include 1,3-diaminocyclohexane and aminocyclohexanemethanamines such as, for example, menthanediamine (4-amino-o~a,-4-trimethylcyclohexane-methanamine) and isophoronediamine (5-amino-1,3,3-trimethylcyclohexane-methanamine) Preferably the polyamine is an aminocyciohexanemethanamine.
More preferably the polyamine is isophoronediamine.
In addition to carbon, hydrogen, and oxygen~ suitable carboxylicacids may optionally contain elements such as, for example, nitrogen, sulfur, and :-.,. ;, lO9X:97 halogens. Suitable acids include aliphatic and aromatic mono- and polycarboxylic acids having a melting point above 25C. Examples of aliphatic acids include oxalic, malonic acid, maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, and tricarballyic acid.
Examples of aromatic acids include benzoic and phthalic acid. Advantageously the carboxylic acid contains from two to thirty carbon atoms, preferably three to ten carbon atoms. More preferably the carboxylic acid i8 an aliphatic dicarboxylic acid containing from four to six carbon atoms. Most preferably the carboxylic acid is succinic acid, adipic acid or mixtures thereof.
The amine salt is preferably prepared as an aqueous solution by dissolving the amine in water and adding approximately the stoichiometric equivalent amount of acid. As water is usually metered into the mixing chamber of a foam head, it is preferable to prepare the aqueous amine salt solution at a concentration - such that each unit volume of solution contains the required amount of water and amine salt. This aqueous - -stream may also contain other components such as, for example, catalyst, cell control agent or additional crosslinking agents. The invention is not based upon -a specific concentration range for use of the amine salt crosslinking agent. Generally they are employed - in amounts from 0.1 to 10 parts by weight per 100 ~ -parts of polyol. optimum concentrations will vary depending upon the choice of polyamine and carboxylic acid. optimum results for the isophoronediamine--succinic acid salt and the isophoronediamine-adipic 1/,708-F -3-,: :, lOgzz ~
acid salt are obtained when they are employed in the range of 3 to 5 parts by weight per 100 parts of polyol.
As a preferred embodiment, one or more auxili-S ary crosslinking agents kr.own in the art are added to the foaming formulation with the amine salt crosslink-ing agent. Auxiliary crosslinking agents include low molecular weight amines and hydro~yl containing compounds such as, for example, tris(polyoxyalkylene alkanol)amines;
mono-, di-, and tri-ethanolamines; mono-, di-, and tri-iso-propanolamines; oxyhydrocarbon or oxyhydrocarboxy deriva-tives of isocyanuric acid or aryl substituted isocyanuric acid; oxydianiline; an aliphatic diol or a polyether diol having an hydroxy equivalent weight less than 300 and preferably less than 200; and aliphatic, alicyclic and aromatic polyamines having from 1 to about 30 carbon atoms. Advantageously the auxiliary crosslinking agent is the same polyamine as that used to prepare the amine salt. Auxiliary crosslinking agents are generally em-ployed in the range from 0.1 to 5 parts by weight per 100 parts of polyol.
Suitable polyether polyols are obtained by reacting an alkylene oxide such as, for example, ethylene oxide, propylene oxide, butylene oxide or ~5 a mixture of two or more thereof, with an initiator having a multiplicity of active hydrogen atoms such as, for example, alkylene glycols, glycerol, trimethyl-ol propane, pentaerythritol, sorbitol, hexane triol, sucrose, ethylenediamine, polyalkylenepolyamines, phenol-aldehyde condensates, bi~phenol A, or a mixture 1/,708-F ~4~
1092Z~7 of two or more thereof. Polyether polyols derived from propylene oxide or a mixture of propylene oxide and ethyl- -ene oxide either contain only secondary hydroxyl groups or a mixture of secondary and primary hydroxyl groups.
S By reacting these polyols with ethylene oxide one can obtain modified polyols having a high primary hydroxyl content. These modified polyols are described as "cappedn or "tipped" polyether polyols and can be used with advantage -- -in the process according to the invention. Suitable polyether polyols have a number average molecular weight range from 200 to 7000, preferably 3000 to 7000. Suitable polyols preferably have a hydroxyl number range from 24 to 56.
In preparing the polyurethane foams of the -present invention, any of a wide variety of polyiso- ---cyanates may be employed either alone, as isomer mixtures, or as mixtures of different polyisocyanates.
Aromatic, aliphatic and alicyclic diisocyanates and combinations of these types are useful. Representa- ~-tive polyisocyanates include 2,4-toluenediisocyanate (TDI), 2-6-toluenediisocyanate, methylene-bis~p-phenyliso- -cyanate) t polymethylene polyphenylisocyanates, crude -~
or undistilled isocyanates, dimers or trimers of poly-isocyanates and prepolymers made by the reaction of a stoichiometric excess of such isocyanates with any of the above mentioned polyether polyols or with other compounds having sites reactive with isocyanates.
Arylene diisocyanates, i.e. those in which each of the two isocyanate groups is attached directly to an aromatic ring, are preferred.
17,708-F ~5-~ . .
Catalyst systems employed include, for example, tertiary amine catalysts such as triethylenediamine, dimethylethanolamine, bis-2(N,N-dimethylaminoethyl) ether, and N-ethylmorpholine, which catalyze the water-isocyanate reaction as well as the hydroxyl--isocyanate reaction and the usual organo-tin cata-lysts including stannous octoate. When the process of the invention is used to produce molded flexible poly-urethane foam, usually organo-tin catalysts are not incorporated into the foaming formulation. When the process of the invention is used to produce slab stock flexible polyurethane foams, usually organo-tin cata-lysts are incorporated into the foaming formulation.
Sufficient catalyst is used to produce desired foaming parameters such as, for example, cream time and rise time. The optimum concentration of the catalyst system for a given foaming formulation is determined by incrementally adjusting the concentration until the desired conditions are met.
The density of the foam is varied by using different proportions of a blowing agent. In addi-tion to reasons of commercial considerations, water is the most convenient blowing agent to employ. Water offers an additional advantage as a blowing agent in that it not only undergoes an in situ reaction with the isocyanate group to produce carbon dioxide but also results in urea linkages which serve as crosslinking sites. Other blowing agents which may be employed include methylene chloride and fluorocarbons.
17,708-F -6-', 109~7 Co~mon cell control agents which may be optionally incorporated in the foaming formulation are exemplifled by sliicone surfactants, such as, for example, siloxane-gl~col copolymersJ which are employed to generally -improve the miscibllity of the components and aid in controlling the size of the cells in the foam. In the case of high resiliency foams, polydimethyl-siloxyanes, polyphenylmethylsiloxanes, or low activity polyoxyalkylene-polydimethylsiloxane block copolymers are employed to produce foams with a high proportion of open cells, The polyurethane foams according to the invention can be made by prepolymer, semi-prepolymer and one-shot foam techniques.
Such techniques are well known to those skilled in the art and can be varied depe~ding upon the type of product desired.
In order that the invention be well understood, the following examples are given by way of illustration only. Foam properties were measured according to ASTM D-1564 and D-2406. -Examples of high resilient cold cure polyurethane foams using isophoronediamine-succinic acid amine salt crosslinking agent and isophorone-diamine as the auxiliary crosslinking agent and diethanolamine as an auxiliary crosslinking agent were compared with high resilient foams using Amine 70 as the crosslinking agent. An aqueous solution of the amine salt, hereinafter known as Amine Salt A, was prepared by dissolving isophoronediamine in water and then adding the stoichiometric equivalent amount of succinic acid.
B
. . .
- , , ;: , .. . ..
lO9ZZ~7 Additional isophoronediamine, hereinafter known as Auxiliary Crosslinking Agent E, and diethanolamine, hereinafter known as Auxiliary Crosslinking Agent F were added to the amine salt solu~ion. The proportions of amine, carboxylic acid and water were equivalent to those desired for the foaming formulation. For Comparative Runs A and B, Amine 70, hereinafter known as Amine Crosslinking Agent C, was dissolved in water in proportions needed for the foaming formulations. Amine 70 is a still bottom product obtained in the reaction of ethylenediamine with ethylene oxide. The polyol used in Examples 1 and 2 and Comparative Runs A and B, hereinafter known as Polyol G, was a commercial polyether triol made by reacting glycerol with propylene oxide and end capping with ethylene oxide. Polyol G has an hydroxyl equivalent weight of 1570 and contains 60 to 80% primary hydroxyl groups. The poly- -isocyanate used, hereinafter known as Polyisocyanate I, was an 80/20 mixture of 2,4-/2,6-toluenediisocyanate having an isocyanate equivalent weight of 87.
A solution containing 33 weight percent triethylenediamine in dipropylene glycol, hereinafter known as Catalyst K, was used as a catalyst in both examples and both comparative runs. Dimethylethanolamine, hereinafter known as Catalyst L, and stannous octoate, hereinafter known as Catalyst P, were additionally used in Comparative Runs A and B. A polydimethylsiloxane, here-inafter known as Cell Control Agent Q, having a molecular weight of a~out 900 and diluted in a ratio of 1:9 with an isobutyrate plasticizer, was used in both examples and both comparative runs.
.B -8-.. . .
-~ 109Z~97 In each of the examples the aqueous solution of the amine salt crosslinking agent~ the auxiliary crosslinking agent, the polyol, the - catalyst and the cell control agent were blended together until the components were equally dispersed. Then the polyisocyanate was added and the foaming formulation stirred for several more seconds. The foaming formulation was then poured into an open container and allowed to rise. The foam was cured at room temperature for 36 hours before testing. Densities of the foams were varied by varying the amounts of water and isocyanate. The formulations, foam conditions and foam properties are shown in Table I.
Examples of the invention showed an improvement in tensile strength, tear resistance, 40% compression load deflection (CLD), and CLD
: ~odulus 65/25 over the comparative runs. The improvement in 40% CLD ranged from 48 percent to 67 percent when comparing foams of similar densities. It should be noted that the examples required a larger proportion of Catalyst K
than the comparative runs.
TABLE I
Formulation (parts by weight) 1 2 A B
Amine Salt Crosslinking Agent A 3.6 3.6 Amine Crosslinking Agent C --- --- 2.0 2.0 Auxiliary Crosslinking Agent E 0.4 0.4 --- ---Crosslinking Agent F 0.5 0.1 --- ---Polyol G lO0 lO0 lO0 lO0 Polyisocyanate I 30.5 36.530.0 35.0 Catalyst K 1.25 1.1 0.3 0.3 Catalyst L --- --_ 0.5 0.4 ~B -9- :
, . . .
TABLE I ~Continued) Formulation (parts b weight) 1 2 A B
~ Y . . _ . _ . . _ Catalyst P --- --- 0.15 0 25 Cell Control Agent Q 0.1 0.1 0.1 0.1 Wa~er 2.0 2.5 2.0 2.5 Foam Conditions Cream Time, seconds 10 9 6 6 Rise Time, seconds 135 130 110 105 Foam Pro erties p Density, kg/m3 39 0 34.540.0 35.0 Tensile Strength, kg/cm2 1.1 1.00.80 0.75 Elongation, % 160 155 180 170 Tear Resistance, kg/cm 0.55 0.50 0.4 0.4 Resilience, % 62 62 66 66 40% CLD, g/cm 34 30 23 18 Hysteresis, % 21 22 18 19 CLD Modulus 65/25 3.1 3.0 2.7 2.7 Examples 3-7 and Comparative Runs C and D illustrate molded foams prepared from hand mixed formulations. The foaming formulations were -prepared as described in Examples 1 and 2 and Comparative Runs A and B. Amine -~Salt Crosslinking Agent A and Auxiliary Crosslinking Agent E were also used in Examples 3-7 in the same manner as Examples 1 and 2. Additional Auxiliary Crosslinking Agent F was added to the foaming formulations of the Examples. -Comparative Run C employed an amine crosslinker which is diisopropanolamine, hereinafter known as Amine Crosslinking Agent D. Comparative Run D did not employ an amine crosslinking agent and neither Comparative Run ' ~
B -lo-. . .
~, . ,. ~ , . ., ; ~ . , ,. "
lO~
C or D employed an auxiliary crosslinking agent. The polyether polyol used for Examples 3-7 and Comparative Runs C and D, hereinafter knbwn as Polyol H, is a commercial polyether triol made by reacting glycerol with propylene oxide and ethylene oxide and end capping with ethylene oxide Polyol H has a hydroxyl equivalent weight of 1570 and contains 60 to 80 percent primary hydroxyl groups. Polyisocyanate I was used for Examples 3-7. Comparative Runs C and D employed a polyisocyanate which was a solution of trimerized TDI in 80% (2,4-)-20% (2,6-) TDI, hereinafter known as Polyisocyanate J.
Catalyst K was used for Examples 3-7 and Comparative Runs C and D. Catalyst L was used for Comparative Runs C and D. For Examples 3-7, additionally bis-2(N,N-dimethylaminoethyl)ether, hereinafter known as Catalyst M, was added. For Comparative Runs C and D, addition-ally N-ethyl morpholine, hereinafter known as Catalyst N, was added.
Examples 3-7 contained Cell Control Agent Q, while Comparative Runs C and D contained a phenylmethylsiloxane, hereinafter known as Cell Control Agent R.
After mixing of the components was completed, each foaming formulation was poured into a 10 x 35 x 35 centimeter aluminum mold heated to 45-50C. Each foam sample was removed after 10 minutes -in the mold. Formulations, foam conditions and foam properties are shown in Table II. -Examples 3-7 have higher resilience, lower hysteresis loss ~ -and equal or higher CLD Modulus 65/25 than Comparative Runs C and -D. The high 40~ CLD of Comparative Run C was obtained by employing a premium '' .
10922g7 amine crosslinking agent not in wide-spread use because of its cost, as well as a special polyisocyanate and a special cell control agent which are higher cos~ components when compared with the corresponding components of Examples 3-7. Example 4 had the same density as Comparative Run D, The improved resilience and CLD Modulus 65/25 and lower hysteresis loss are accomplished with lower cost components than Comparative Run D.
High resiliency flexible polyurethane foam employing styrene acrylonitrile copolymer polyols had load bearing characteristics similar to Comparative Run D, when measured on foams having the same density. Polyisocyanate J employed in Comparative Runs C and D and the copolymer polyols require special storage conditions to prevent contamination of other materials.
T~BLE II
Formulations (parts by weight) 3 4 5 6 7 C D
-Amine Salt Cross- 3.9 4.9 3.9 3.2 3.9 --- ---linking Agent A
Amine Crosslinking --- --- --- --- --- 2.0 ---Agent D
Auxiliary Cross- 0.7 0.1 0.7 1.1 0.7 --- ---linking Agent E
Auxiliary Cross- 0.75 1.0 0.75 0.5 0.75 --- - ---linking Agent F
Polyol H 100 100 100 100 100 100 100 Polyisocyanate I 41.5 42.0 41.5 36.0 36.5 --- ---Polyisocyanate J --- --- --- --- --- 49.0 46.0 Catalyst ~1.25 1.25 1.25 1.01.25 0.3 0.4 Catalyst L --- --- --- --- --- 0.5 0.5 Catalyst M0,15 0.15 0.20 1.15 0.15 -' 10~
TABLE II ~Cont.) Formulations (parts by wei~ht) 3 4 5 6 7 C D
_ Catalyst N ~ - --- --- 0-5 0-5 Cell Control Agent Q 0.1 0.1 0.05 0.1 0.1 --- ---Cell Control Agent R --- --- --- --- --- 1.0 1.0 Water 3.0 3.0 3.0 2.5 2.5 3.1 3.1 Foam Conditions Cream Time, Seconds 9 8 9 8 8 6 6 Rise Time, Seconds 90 95 90 85 90 90 95 Foam Pro erties P
Density, kg/m3 42 42 42 50 49.5 46 42 Tensile Strength,kg/cm2 1.1 0.9 1.1 1.3 1.2 1.2 1.2 -Elongation, %165 140 135 165 155 135 155 Tear Resistance, kg/cm 0.5 0.5 0.5 0.5 0.5 0.6 0.6 -Resilience, % 63 62 62 62 62 58 57 40% CLD, g/cm2 30.5 33 32 36 37.5 36.5 30.5 Hysteresis, % 20 21 22 19 20 27 25 CLD Modulus 65/25 3.0 3.1 3.1 3.3 3.1 3.0 3.0 Examples 8-15 illustrate high resiliency flexible slab stock polyurethane foams prepared on large scale produc~ion type foam machines. -~
Examples 8-14 employed a Viking foam head and Example 15 employed a Hennecke UBT foam head. The foaming formulations for all examples contained Auxiliary Crosslinking Agent E, Polyol H, Polyisocyanate I, Cell Control Agent Q, and stannous octoate, hereinafter known as Catalyst P. Examples 8-10 employed an aqueous solution of Amine Salt Crosslinking Agent A prepared ~09~g7 as described in Examples 1 and 2. Examples 11 and 15 employed an aqueous solution of an amine salt crosslinking agent prepared from isophoronediamine and adipic acid hereinafter known as Amine Salt Crosslinking Agent B, in the same manner as described for Amine Salt Crosslinking Agents A and B. Examples 12-14 employed both Amine Salt Crosslinking A&ents A and B. Examples 8-11 and 15 additionally employed a Catalyst M. Examples 12-14 additionally employed Catalyst L. Example 15 employed solid 100% triethylenediamine, hereinafter known as Catalyst 0. Formulations, foam conditions, and foam properties are shown in Table III.
TABLE III
Formulations (parts by wei~ht) 8 9 10 11 12 13 14 15 -Amine Salt Crosslinking Agent A 2.9 2.9 2.9 --- 2.4 2.42.4 Amine Salt Crosslinking Agent B --- --- --- 3.3 0.5 0.50.5 3.0 Auxiliary Crosslinking Agent E 0.6 0.6 0.61.2 0.6 0.60.6 1.0 Polyol H lO0 lO0 lO0lO0 lO0 lO0lO0 lO0 Poly-isocyanate I30 30 30 31 30 30 30 36 Catalyst K 0.4 0.4 0.40.75 0.75 0.750.75 ---Catalyst L --- --- --- --- 0.5 0.5 0.5 -__ Cstalyst M 0.2 0.2 0.20.2 --- --- --- 0.1 Catalyst 0 --- --- --- --- --- --- --- 0.3 Catalyst P0.25 0.2 0.150.2 0.25 0.20.15 0.3 B 14 _ ..
::
- tO~Z297 TABLE III (Cont.) Formulations (parts by wei~ht) 8 9 10 11 12 13 14 15 Cell Size Control ~gent Q 0 4 0.3 0.2 0.4 0.4 0.3 0.2 0.2 Water 2.0 2 0 2.0 2.0 2 0 2.0 2.0 2.5 Foam Conditions Polyol through- - -put, kg/min.12 12 12 12 12 12 12 50 Polyol/TDI
temp. C.20/20 20/20 20/20 20/20 20/2020/20 20/20 22/22 Stirrer, rpm 3600 3600 3600 3600 3600 3700 3700 3000 Air at 30 psi, l/min1 0 1,0 1.0 0.85 0.85 0.85 0.85 0.7 Conveyor ~.
Speed, m/min 1.6 1.5 1.5 1.7 1.6 1.6 1.6 3.1 Conveyor Angle, 5 5 5 5 5 5 5 5 Cream Time, seconds 9-10 --- --- 8 . 8 --- --- 7 ~ ~
Rise Time, :
seconds --- 140 --- --- --- 135 --- 135 Foam Properties -Density, ~ -kg/m3 42 42 41.5 39 41 41 40 36 Tensile Strength, kg/cm2 0.75 0.7 0.7 1.2 0.85 0.85 0.9 0.8 Elongation, % 145 130 120 250 170 180 160 160 -Tear Resistance, kg/cm 0.4 0.3 0.3 0.5 0.35 0.3 0.3 0.35 Resilience, % 61 62 60 59 59 60 61 61 Compression set, % 3 5 4 4 9 10 10 8 6 .
j lO9ZZ n TABLE III (Cont.) Formulations ~parts by wei~ht) 8 9 10 11 12 13 14 15 . . _ 40 %2CLD, g/cm 35 39 38 30.5 32 33.5 33.5 3~.5 ILD, lbs @25% 35.5 40 39 3033.5 33.5 34 32 Hysteresis,%22 22 22 22 22 22 22 22 CLD Modulus 65/25 2.75 2.82.75 2.92.8 2.8 2.8 2.7 There was no shrinkage in any of the foams after cure and the foams were easy to crush after three days. Combinations of catalysts were used at varying concentrations to illustrate in the examples that a variety of foaming formulations will produce flexible foams having commercially desirable properties. The amine salt crosslinking agents exhibited r.o catalytic effect of their own. Catalyst levels for the examples were higher than for the comparative runs. The variation in foam properties in general follows the expected pattern for one shot flexible polyurethane foams.
Examples of foaming formulations employing amine salt cross-linking agents in general exhibited longer cream times and rise times than for the comparative runs. This supports the concept that the amine salt crosslinking agent reacts later in the reaction when the heat of the reaction dissociates the amine salt. The amine salts did not have the characteristic odor of the amine. However, during the later stages of the foaming reaction, the characteristic odor was again -detected. This observation ~092297 also supports the concept of the amine ~alt as a latent crosslinking agent.
Examples 16 and 17 were aimed at proving u~e-fulness of amine salts for conventional flexible foams.
The polyol used in examples 16 - 17 and comparative runs E and F, hereinafter known as Polyol T, was a commercial polyether triol made by reacting glycerol with propylene oxide and ethylene oxide in a mixed feed. Polyol T has a hydroxyl equivalent weight of 1360.
The polyisocyanate used, hereinafter known as Polyisocyanate I, is an 80/20 mixture of 2,4-/2,6--toluenediisocyanate having an isocyanate equivalent weight of 87.
; Catalysts K, L, and M were used again as blowing catalysts. A polyoxyalkylenepolydimethylsiloxane co-polymer, hereinafter known as Cell Control Agent U was used in both examples and both comparative runs. Cata-lyst P, the polymerization catalyst, was also used for both examples and comparative runs.
In these examples the aqueous solution of the amine salt crosslinking agent, the auxiliary cross-linking agent, and the tertiary amine catalysts were mixed into the water stream. The stannous octoate cata-lyst and the silicone surfactant were mixed into the polyol.
While stirring the polyol side at a high speed, the water stream and the polyisocyanate were added simultaneously. Then the foaming formulation 17,708-F -17-~ . .
lO9Z297 was stirred to several more seconds. The foaming formulation was then poured into an open container and allowed to rise.
Densities of these foams were varied by varying the amounts of water and isocyanate. Formulations, foam conditions, and foam preperties are shown in Table IV.
TABLE IV
Formulation (parts ~ ht) 16 17 E F
Amine salt crosslinking agent A 3.6 3.6 Auxiliary crosslinking agent E 0.4 0.4 --- ---Polyol T100 100 100 100 Polyisocyanate I 42.5 52.5 40.5 50.5 Catalyst K --- --- 0.35 0.30 Catalyst L 0.5 0.5 -~
Catalyst M 0.15 0.12 --- ---Silicone surfactant U 0.70.8 0.7 0.8 Water 3.04.0 3.0 4.0 Catalyst P 0.100.10 0.125 0.125 Foam Conditions Cream time, seconds 10 10 8 8 Ri~e time, ~econds 115 100125 115 Foam properties Density kg/m 30.0 24.031.025.0 40% CLD g/cm2 33.0 30.533.030.0 CLD modulus 65/25 2.5 2.42.1 2.0 Examples of the invention show an improvement in CLD modulus 65!25 at same hardness over the compara-tive runs. Improvement in modulus was 20%.
i:
17,708-F -18- ~
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for producing polyurethane foam which comprises reacting in one step a polyether polyol and a crosslinking agent with a polyisocyanate in the presence of a catalyst and a blowing agent characterized in that at least a major portion of the crosslinking agent is a soluble amine salt obtained by reacting a cycloaliphatic polyamine having at least two primary amine groups with approximately the stoichiometric equivalent amount of a carboxylic acid.
2. The process of claim 1 characterized in that the polyamine is an aminocyclohexanemethanamine.
3. The process of claim 2 characterized in that the polyamine is iso-phoronediamine.
4. The process of claims 1 or 3 characterized in that the carboxylic acid contains from two to thirty carbon atoms.
5. The process of claim 1 characterized in that the carboxylic acid contains from three to ten carbon atoms.
6. The process of claim 5 characterized in that the carboxylic acid is an aliphatic dicarboxylic acid containing from four to six carbon atoms.
7. The process of claims 1 or 3 characterized in that the carboxylic acid is succinic acid, adipic acid, or mixtures thereof.
8. The process of claim 1 characterized in that the amine salt is employed in amounts of from 0.1 to 10 parts by weight per 100 parts by weight of polyol.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US62748975A | 1975-10-30 | 1975-10-30 | |
| US627,489 | 1975-10-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1092297A true CA1092297A (en) | 1980-12-23 |
Family
ID=24514860
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA249,596A Expired CA1092297A (en) | 1975-10-30 | 1976-04-05 | Flexible polyurethane foams |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS601329B2 (en) |
| AU (1) | AU509781B2 (en) |
| BE (1) | BE840422A (en) |
| CA (1) | CA1092297A (en) |
| DE (1) | DE2614203A1 (en) |
| ES (1) | ES446609A1 (en) |
| FR (1) | FR2329692A1 (en) |
| GB (1) | GB1545318A (en) |
| IT (1) | IT1058063B (en) |
| NL (1) | NL7603351A (en) |
| SE (1) | SE431556B (en) |
| YU (1) | YU9076A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2915468A1 (en) * | 1979-04-17 | 1980-10-30 | Basf Ag | METHOD FOR PRODUCING URETHANE GROUP CONTAINING POLYISOCYANURATE FOAMS |
| DE2915458A1 (en) * | 1979-04-17 | 1980-10-30 | Basf Ag | METHOD FOR PRODUCING POLYURETHANE FOAMS |
| US4743628A (en) * | 1986-08-06 | 1988-05-10 | Air Products And Chemicals, Inc. | Polyurethane foams incorporating alkoxylated aromatic diamine and acetylenic glycol |
| JPH04136129U (en) * | 1991-06-11 | 1992-12-17 | 松下産業株式会社 | Bag lining fabric attachment structure |
-
1976
- 1976-01-14 YU YU00090/76A patent/YU9076A/en unknown
- 1976-03-31 NL NL7603351A patent/NL7603351A/en not_active Application Discontinuation
- 1976-04-01 ES ES446609A patent/ES446609A1/en not_active Expired
- 1976-04-02 DE DE19762614203 patent/DE2614203A1/en not_active Withdrawn
- 1976-04-02 AU AU12601/76A patent/AU509781B2/en not_active Expired
- 1976-04-02 IT IT48843/76A patent/IT1058063B/en active
- 1976-04-05 CA CA249,596A patent/CA1092297A/en not_active Expired
- 1976-04-05 GB GB13715/76A patent/GB1545318A/en not_active Expired
- 1976-04-05 SE SE7604001A patent/SE431556B/en unknown
- 1976-04-06 BE BE165873A patent/BE840422A/en not_active IP Right Cessation
- 1976-04-06 FR FR7609957A patent/FR2329692A1/en active Granted
- 1976-04-06 JP JP51037875A patent/JPS601329B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2329692A1 (en) | 1977-05-27 |
| ES446609A1 (en) | 1977-06-01 |
| JPS601329B2 (en) | 1985-01-14 |
| SE431556B (en) | 1984-02-13 |
| AU1260176A (en) | 1977-10-06 |
| BE840422A (en) | 1976-10-06 |
| FR2329692B1 (en) | 1979-06-22 |
| IT1058063B (en) | 1982-04-10 |
| GB1545318A (en) | 1979-05-10 |
| JPS5254796A (en) | 1977-05-04 |
| SE7604001L (en) | 1977-05-01 |
| DE2614203A1 (en) | 1977-05-12 |
| YU9076A (en) | 1982-05-31 |
| NL7603351A (en) | 1977-05-03 |
| AU509781B2 (en) | 1980-05-22 |
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