DE2517804A1 - PROCESS FOR PRODUCING HIGHLY ELASTIC, CELLULAR POLYURETHANE - Google Patents

Description

Folder 23748 - Dr. K / by
Case 1063

FURANE PLASTICS, INC. Los Angeles, California, USA

Process for the production of highly elastic, cellular

Polyurethane

Priority: 4/22/74 - USA

The invention relates to new polyurethane elastomers and foams and to new compositions and methods for Manufacture of the same.

It is well known that a polyurethane can be made by using an organic polyfunctional Isocyanate with organic compounds that are two or more reactive hydrogen determinable by the Zerewitinoff reaction have atoms. If this reaction occurs under what-

509844/1020

Ser-free conditions is carried out, then the resulting polyurethane is elastomeric. If a cellular or foamed If product is desired, then water and an excess of isocyanate must be added to the mixture. When the water with the excess isocyanate groups that were not previously have been reacted, reacts, then carbon dioxide is formed and retained in the reaction mixture. The most diverse Materials have been used as catalysts or activators in the manufacture of polyurethanes.

The production of a foam from polyurethanes requires a predetermined control of the blowing or gas formation reaction in which the carbon dioxide is set free will. While many systems have been tried, there is no simple commercial system that can be used to manufacture made possible by polyurethane elastomers.

The invention was now based on the object of a new foamed To create a product based on polyurethane. Another object of the invention was to provide a new foaming agent for polyurethane prepolymers for those applications where safety is important.

The invention thus relates to a method for the production of elastomeric or cellular polyurethanes, which is carried out thereby is that an organic polyisocyanate with a polyalkylene polyol, which can be determined by the Zerewitinoff method contains reactive hydrogen atoms in the presence a crosslinking agent, which is a compound of the formula

S-R-S

- 2 5098V4 / 1020

where R is hydrocarbon and R ^{1 is} hydrogen, halogen or hydrocarbon.

According to a preferred embodiment, the invention relates to a method for producing polyurethane foams and elastomers, which is carried out by adding a mixture of a polyalkylene polyol obtained by the Zerewitinoff method has determinable reactive hydrogen atoms and has a molecular weight of at least 500, at least one organic polyisocyanate and, as a crosslinking agent, at least one sulfur-containing polyamine of the formula

NH ₂ 'NH ₂

S-R-S

R ¹ R ¹

where R is hydrocarbon and R ^{1 is} hydrogen,

Halogen or hydrocarbon is converted.

In this compound, R can be a hydrocarbon radical, which is preferably selected from alkyl, alkenyl, cycloalkyl, aralkyl, aryl and alkaryl, these radicals also can be inertly substituted. When R is alkyl, it can be straight or branched chain alkyl act, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, Isobutyl, sec-butyl, tert-butyl, n-amyl, neopentyl, isoamyl, n-hexyl, isohexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, Octadecyl, etc. Preferred alkyls are those having about 8 or fewer carbon atoms, i.e., octyl and below. if R represents alkenyl, then it can, for example, vinyl, allyl, 1-propenyl, methallyl, buten-1-yl, buten-2-yl, buten-3-yl, Penten-1-yl, hexenyl, heptenyl, octenyl, decenyl, dodecenyl, Be tetradecenyl, octadecenyl, etc. If R stands for cycloalkyl, then it can be, for example, cyclopentyl, cyclohexyl, Cycloheptyl, cyclooctyl, etc. «, If R stands for aralkyl, then it can be, for example, benzyl, ß-phenylethyl, γ-phenyl-

509844/1020

propyl, β-phenylpropyl, etc. If R stands for aryl, then it can be, for example, phenyl, naphthyl, etc. If R stands for alkaryl, then it can, for example, tolyl, Xy-IyI, p-ethylphenyl, p-nonylphenyl, etc. R can be inert be substituted, i.e. that it can carry non-reactive substituents, such as alkyl, aryl, cycloalkyl, aralkyl, alkaryl, Alkenyl, ether, halogen, nitro, ester, etc. Typical substituted alkyls are 3-chloropropyl, 2-ethoxyethyl, Carboxyethoxymethyl, etc. Typical substituted alkenyls Typical ones are 4-chlorobutyl, J-phenylpropenyl, chloroallyl, etc. substituted cycloalkyls are 4-methylcyclohexyl, 4-chlorocyclohexyl etc. Typical inertly substituted aryls are chlorophenyl, anisyl, biphenyl etc. Typical inertly substituted aryls Aralkyls are chlorobenzyl, p-phenylbenzyl, p-methylbenzyl etc. Typical inert substituted alkaryls are 3-chloro-5-methylphenyl, 2,6-di-tert-butyl-4-chlorophenyl, etc.

The radical R ¹ can be selected from hydrogen, halogen and hydrocarbon. Preferably R ^{1 is} hydrogen. R can be halogen with an atomic weight greater than 19, for example chlorine, bromine and iodine.

When R ^{1 is} a hydrocarbon, it can be the same as R, ie it can be alkyl, aryl and alkenyl including inertly substituted alkyl, aryl and alkenyl. R ¹ is typically methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, amyl, hexyl, octyl, decyl, dodecyl, octadecyl, cyclohexyl, cycloheptyl, vinyl, allyl, 1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, phenyl, naphthyl, phenanthryl, chlorophenyl, nitrophenyl, benzyl, tolyl, ethylphenyl, phenylethyl, chlorobutyl, 2-ethylhexyl, ethoxyethyl, methylcyclohexyl, 3-chloro-2- butenyl, etc. R and R 'can be the same or different, and the two radicals R ¹ can also be the same or different. R ¹ can also be a divalent hydrocarbon, preferably divalent alkyl (alkanediyl), with a cyclic structure having

5 0 9 8 if k / 10 2 0

the nitrogen atom of the dithiocarbamate radical or whereby it forms a bridge structure connecting two dithiocarbamate radicals. R ¹ can be, for example, methylene, ethylene, 1,2-propylene, trimethylene, 1,2-butylene, tetramethylene, pentamethylene, hexamethylene, octamethylene, decamethylene, o-phenylene, m-phenylene, p-phenylene, 4,4 ^f- bisphenylene , α-tolylene, xylylene, etc.

Preferred foaming or blowing catalysts for the invention are bis (o-aminophenylthio) methane, bis (o-aminephenylthio) ethane, Bis (o-aminophenylthio) -1,2-propane and bis (o-amino phenylthio) -1,4-benzene.

Which are used to prepare the polyurethanes of the invention polyols, primary and secondary, hydroxyabgeschlossene polyoxyalkylene ethers having 2 to 4 are ^N Hydroxylgrup- groups and a molecular weight of approximately from 1000 to 10 000. They are liquids or can be used for the processing in Polyurethanschäumvorrichtungen or machines liquefied or melted.

Examples of polyoxyalkylene polyols are linear and branched polyethers with a large number of ether groupings and having at least two hydroxyl groups, being largely free of functional groups other than hydroxyl groups are. Examples of polyoxyalkylene polyols which can be used according to the invention are polyethylene glycols, polypropylene glycols and polybutylene ether glycols. Polymers and copolymers of polyoxyalkylene polyols can be used for the inven methods according to the invention are also used, as are the block copolymers of ethylene oxide and propylene oxide. Examples for copolymers of polyoxyalkylene polyols, which are specifically mentioned here, the ethylene oxide, propylene oxide and butylene oxide adducts of ethylene glycol, propylene glycol, diethylene glycol, Dipropylene glycol, triethylene glycol, 2-ethylhexanediol-1,3, Glycerine, 1,2,6-hexanetriol, trimethylolpropane,

509 844/1020

Trimethylolethane, tris (hydroxyphenyl) propane, triethanolamine, Triisopropanolamine, ethylenediamine and ethanolamine. Linear and branched copolyethers of ethylene oxide and propylene oxide are also used in the preparation of the invention foamed products useful, preference being given to those which have ethylene oxide blocks at the ends, to provide primary hydroxyl groups in the interpolymer and have molecular weights of about 2,000 to 5,000.

Other useful types of polyether polyols are block copolymers, which are made from propylene oxide and ethylene oxide. These polyethers can be broken down into the following represent general formulas:

CH,

H (O-CH ₄ -CH ₈ ) _x (0-CH-CH ₃ ), '(0-CH ₈ -CH ₃ ) _χ 0Η

CH, CH ₅

I I

H (O-CH ₈ -CH ₈ ) _a (O-CH-CH ₂ ) _b (CH ₈ -CH-O) _b (CH ₈ -CH ₂ -0) _a H.

■ Ni-CH ₈ -CH ₃ -N

H (O-CH ₈ -CH ₈ ) _a (O-CH-CH _a ) _b (CH ₈ -CH-O) _b (CH ₈ -CH ₃ -O) _a H.

CH,. CH,

where in formula A all indices x, y and ζ are positive integers in the range from 20 to 70 and in formula B all indices a and b are positive integers in the range from 20 to represent.

Polyethers with a branched chain network are also useful. Such branched chain polyethers can easily from alkylene oxides of the type described above and initiators with a functionality of more than two. Branched polyethers have the advantage that crosslinking is possible without any interaction between

Urea or urethane groups takes place with the isocyanate groups. This has the advantage that a larger proportion of the isocyanate used is responsible for the development of carbon dioxide is available and the total amount of isocyanate required to produce the foamed polymer is less is. Mixtures of polyether polyols can also be used.

Examples of these polyoxyalkylene polyols are polypropylene glycols with average molecular weights from 500 to 5,000 and reaction products of propylene oxide with linear Diols and higher polyols, these higher polyols, when used as reactants, becoming branched Give rise to polyoxyalkylene polyols. Further examples are ethylene oxide / propylene oxide copolymers with average molecular weights from 500 to 5,000, wherein the weight ratio of ethylene oxide to propylene oxide is in the range between 10:90 and 90:10. Also belong here Reaction product mixtures of ethylene oxide and propylene oxide in the proportions mentioned with linear diols and higher Polyols.

Examples of linear diols that act as reactants with one or more alkylene oxides can be used are ethylene glycol, propylene glycol and 2-ethylhexanediol-1,3, and Examples of higher polyols are glycerol, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol and sorbitol.

Other classes of polymers terminated with reactive hydrogen atoms and which are suitable for reaction with polyisocyanates are lactone polymers, and preferably those showing molecular weights ranging from 500 to 10,000.

In the production of a cellular polyurethane, water is used mixed with the condensation product of an alkylene oxide and an organic polyisocyanate to form carbon dioxide,

509844/1 020

that acts as a propellant. Many foaming or blowing catalysts can be used to accelerate the formation of the cellular polyurethane.

It is a feature of the present invention that the synergistic blowing catalyst combination described herein can be used in conjunction with a wide variety of catalysts such as dibutyltin dilaurate and tin (II) -2-ethylhexoate, etc. In the In a preferred embodiment of the process according to the invention, a gelatinization catalyst is preferably used which can be selected from Sh (OCOR) ^ and R ^{1 SnX ^.} Other equivalent gelation catalysts can also be used. In the tin (II) compounds of the formula Sn (OCOR) ₂ , R can be a hydrocarbon radical, such as alkyl, alkenyl, aryl, aralkyl, alkaryl, cycloalkyl, etc. R can be, for example, methyl, ethyl, propyl, isopropyl, η-butyl , Isobutyl, t-butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, oleyl, i.e. 7-heptadecenyl, etc., phenyl, o-, m- or p-tolyl, naphthyl, cyclohexyl, benzyl, etc. . The nature of R, of course, defines the group -OCOR; when R is methyl, this group is, for example, the acetate group. Preferably, however, the group R contains at least about 7 carbon atoms and less than about 17 carbon atoms. When R is heptyl, the -OCOR group can be the 2-ethylhexoate group. When R is 7-heptadecenyl, the -OCOR group is the oleate group, etc. The preferred compounds are tin (II) -2-ethylhexoate and tin (II) oleate.

In the organotin compounds R ¹ SnX ^, R ¹ can be the same as R. Preferably, R 'is a hydrocarbon radical, such as alkyl, alkenyl, aryl, alkaryl, aralkyl, cycloalkyl, etc. R ¹ is, for example, methyl, ethyl, propyl, isopropyl, η-butyl, isobutyl, t-butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, oleyl, ie 7-heptadecenyl etc., phenyl, ο-, m- or p-tolyl, naphthyl, cyclohexyl, bensyl etc. The sum

- 8 5098U / 1020

of a and b is 4, where a and b can be 1, 2, or 3, respectively. The preferred group for R ¹ is the n-butyl group

In the organotin compounds R ' _a SnX _b , X can consist of chlorides and negative radicals of organic carboxylic acids RCOO-, mercaptides RS-, alcohols RO-, esters of mercapto acids ROOC (CH ₂ ) _n S, where R is hydrogen or another of the above mentioned remains. Typical special residues are 2-ethylhexoate, lauryl mercaptide, methoxide and isooctyl thioglycolate.

The preferred organotin compounds R ¹ SnX ,. are those where a and b are 2. This is the case, for example, with dibutyltin dilaurate and dibutyltin di-2-ethylhexoate.

According to the invention, the gel catalyst and the blowing catalyst present in a ratio of 0.01 to 5 parts, e.g. 1 part of the former per part of the latter be. If, in the preferred embodiment, the catalyst combination according to the invention is tin (II) -2-ethylhexoate as a gel catalyst, then the ratio is approximately 1.

Preferably the catalyst mixture is in catalytic amounts corresponding to 0.01 to 5 parts by weight, for example 0.6 parts by weight, per 100 parts by weight of polyol is present. Preferably is the crosslinking agent in an amount corresponding to 0.005 to 10.0 parts by weight, for example 5.0 parts by weight, per 100 Parts by weight of polyol, and the catalyst in catalytic amounts corresponding to 0.005 to 10.0 parts by weight, for example 0.3 parts by weight, per 100 parts by weight of polyol present.

It is a special feature of the invention that the above Combination with a wide variety of blowing or foaming catalysts can be used. Fall under this tertiary amines, metal soaps, in which the metal consists of antimony, bismuth, arsenic, manganese, iron, cobalt, nickel, alkali

5098U / 102Qf

tall (including ammonium), alkaline earth metal, silver, zinc, cadmium, aluminum, or lead. Further examples are organotin compounds of the formula R ', SnX ¹ , in which R ¹ stands for hydrocarbon and X ¹ consists of the negative radical of an organic carboxylic acid, a mercaptan, an alcohol, a phenol or a halogen acid.

Typical tertiary amines that can be used are N-alkyl morpholines, such as N-methylmorpholine and N-ethylmorpholine (NEM) and cyclic triethylenediamine, such as that sold under the trademark DABCO. Particularly preferred blowing catalysts consisting of tertiary amines are N-ethylmorpholine and cyclic triethylenediamine or mixtures thereof, the mixtures for example 1-2 parts by weight of cyclic triethylenediamine 3 parts by weight each Contain N-ethylmorpholine. Tertiary amines, which are used as blowing catalysts, are particularly desirable when rapid rise times are important.

Typical metal soaps that can be used as blowing catalysts are compounds of the formula M (OOCR "), wherein M consists of antimony, bismuth, arsenic, manganese, iron, cobalt, nickel, silver, zinc, cadmium, aluminum and lead, R "consists of a hydrocarbon group and η a small whole «? number corresponding to the valence of M, typically 1, 2, 3, etc. Preferably η is 1 and is the acid of which the soap is derived from, monobasic. Examples of hydrocarbon groups represented by R " are aliphatic or cycloaliphatic groups such as alkyl, alkenyl etc., and corresponding cyclic groups such as e.g. cycloalkyl, etc.} substituted aryl groups such as phenyl Phenyl, naphthyl, etc .; Aralkyl groups such as benzyl, styryl, tinamyl, etc .; Alkaryl groups such as tolyl, xylyl etc.; and cycloaliphatic groups such as naphthenic acid groups, etc. Other corresponding groups can also be used will. In a preferred embodiment, R "

- 10 -

50984A / 1020

an alkyl group having less than about 21 carbon atoms. Typical of the acids from which the soaps are made are acetic acid, propionic acid, butyric acid, caproic acid, caprylic acid, capric acid, stearic acid, oleic acid etc. Naphthenic acids can also be used. The commercial acid mixtures known as "Talltflfettsäuren" known can also be used. If the metal M consists of antimony, bismuth or arsenic, then the preferred group R "may be an aliphatic group having 6-21 carbon atoms. Typical preferred acids, from which these special soaps can be made are 2-ethylhexanoic acid, pelargonic acid, oleic acid, tetrachlorobenzoic acid, Cyclohexylcarboxylic acid and commercial mixtures of tall oil fatty acids.

Special metal soaps are; Antimony tri-2-ethylhexoate, antimony trip el argonate, arsenic trioleate, antimony tritallate, bismuth tri-2-ethylhexoate, Arsenic triple argonate, antimony tri (tetrachlorobenzoate), Antimony tri (cyclohexyl carboxylate), bismuth trioleate, Iron (III) stearate, manganese (II) stearate, cobalt (II) stearate, Cobalt (II) naphthenate, iron (III) linoleate, manganese (II) linoleate, Iron (ll) stearate, nickel stearate, calcium naphthenate, Ammonium stearate, dimethylammonium stearate, trimethylammonium stearate, Calcium stearate, magnesium stearate, barium stearate, lithium stearate, sodium stearate, strontium stearate, Potassium oleate, ammonium tallat, strontium-2-ethylhexoate, lead naphthenate, Zinc naphthenate, aluminum monostearate, aluminum distearate, Aluminum tristearate, lead (II) stearate, basic Lead (II) stearate, zinc stearate, cadmium stearate, silver stearate, Silver acetate and lead pelargonate. Preferred metal soaps are: antimony tritallate, manganese linoleate, iron (II) stearate, Nickel stearate, calcium naphthenate, barium stearate, sodium st ear at, calcium stearate, zinc naphthenate, lead (II) stearate and aluminum distearate. Particularly preferred metal soaps are: manganese linoleate, calcium naphthenate, cadmium stearate and especially antimony tritallate.

- 11 -

509844/1020

If a blowing catalyst is used according to the invention, then the curing catalyst can be used in a ratio of 0.1-5 parts by weight per part by weight of blowing catalyst may be present, a ratio of 0.5-2.5: 1 being preferred.

Preferably the catalyst mixture is in catalytic amounts corresponding to 0.01 to 5 parts by weight, for example 0.6 parts by weight per 100 parts by weight of polyol. Preferably is the propellant catalyst in a catalytic amount corresponding to 0.005 to 4.95 parts by weight, for example 0.3 Parts by weight per 100 parts by weight of polyol and the gel catalyst in catalytic amounts corresponding to 0.005 to 4.2 parts by weight, for example 0.3 part by weight per 100 parts by weight of polyol is present.

The method according to the invention is particularly suitable for production of both cellular polyurethanes and non-porous polyurethane plastics. The crosslinking compositions, created in accordance with the invention are in the manufacture of elastomeric or highly resilient urethane products by a casting process or by a process in which a grindable rubber is formed. at Process of this type is the condensation product of an alkylene oxide with an organic polyisocyanate and at least a compound of the formula

S-R-S

reacted, where R is hydrocarbon and R ^{1 is} hydrogen, halogen or hydrocarbon.

A wide variety of polyisocyanates can be used in accordance with the invention, although diisocyanates are preferred. Suitable polyfunctional isocyanates are alkylene diisocyanates,

such as hexamethylene diisocyanate and decamethylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate and isomers or mixtures of the same. Triisocyanates, typically obtained by reacting 3 moles of an arylene diisocyanate with 1 mole of a triol, such as the reaction products obtained from 3 moles of tolylene diisocyanate and 1 mole of hexanetriol, can also be used. A preferred polyisocyanate is the mixture of 80 % 2,4-tolylene diisocyanate and 20 % 2,6-tolylene diisocyanate.

As used herein, the term "isocyanates" refers to on polyisocyanates and on polyisothiocyanates, especially diisocyanates and diisothiocyanates. True was the invention has been described in terms of the reaction of certain diisocyanates, but the invention is generally based on the reaction any compound which contains two or more groups of the formula -N = C = G, where G is oxygen or sulfur stands. Compounds within this specific definition are polyisocyanates and polyisothiocyanates in general formula

R (NCG) _x

wherein χ is 2 or more and R is alkylene, substituted alkylene, arylene, substituted arylene, a hydrocarbon or a substituted hydrocarbon having one or two aryl / NCG bonds and one or more alkyl / NCG bonds or a hydrocarbon or substituted hydrocarbon with a variety of either aryl / NCG bonds or alkyl / NCG bonds. R can also be such a radical as -RZR, where Z 'is any divalent radical such as -0-, -0-RO-, -CO-, -CO ₂ -, -S-, -SRS-, -S0 _£ - etc. Examples of such compounds are hexamethylene diisocyanate, 1,8-diisocyanate-p-methane, xylylene diisocyanate, (OCNCH ₂ CH ₂ OCH ₂ ) ₂ , 1-methyl-2,4-diisocyanate-cyclohexane, phenylene -

- 13 -, 5098 4 4/1020

diisocyanate, tolylene diisocyanate, chlorophenylene diisocyanate , Diphenylmethane-4,4'-diisocyanate, naphthalene-1,5-diisocyanate, Triphenylmethane-4,4 ', 4 "-triisocyanate, xylene- <x, <x« - diisothiocyanate and isopropylbenzene ct ^ diisocyanate.

This subheading also includes dimers and trimers of isocyanates and diisocyanates and polymeric diisocyanates of the general formula

(RNCG) _x and ZH (NCG) _x Zy

wherein χ and y are each 2 or more, and also compounds the general formula

M (NCG) _x

wherein χ is 2 or more and M is a difunctional or polyfunctional atom or a difunctional or polyfunctional group. Examples of this type are ethylphosphonic acid diisocyanate, CpH ₁ -P (O) (NCO) ₂ , phenylphosphonic acid diisocyanate, CgHcP (NCO) ₂ , compounds with a group of the formula = Si-NCG, isocyanates derived from sulfonamides (RSOpNCO) , Cyanic acid and thiocyanic acid.

Substances with two or more can be determined by the Zerewitino ff method active hydrogen atoms which can be used according to the invention are those organic compounds which. two or more reactive hydrogen atoms that react with organic polyfunctional isocyanates to form Urethane polymers react. The amount of isocyanate is generally in the range of 1 to 7 equivalents, preferably 2 to 6 equivalents, per equivalent of polyether.

The reaction of excess diisocyanate with a polyoxypropylene glycol results in a polymer with terminal isocyanate groups. When it is desired to form a foam, the mixture of isocyanate-modified polyether reacts

5098447

through these isocyanate groups with a chain extender that contains active hydrogen, such as water. This includes various reactions that take place simultaneously, such as the reaction between the isocyanate groups and water, whereby urylene groups (-NHCONH-) and carbon dioxide arise, as well as the reaction of the so formed Urylene groups with unreacted isocyanate groups, whereby biuret crosslinking groups are formed. Depending on the desired density of the urethane foam and the amount of crosslinking agent should be the total isocyanate equivalent to Be active hydrogen equivalent such that a ratio from 0.8 to 1.2, preferably 0.9 to 1.1 equivalents of isocyanate is present per equivalent of active hydrogen.

Cell modifiers such as silicones, for example trimethyl-terminated DimethylpοIysiloxane, can according to of the invention can also be used.

Other generally known additives can be added to the polyurethane, such as clay, talc, TiO ₂ , silicon dioxide and hydrated silicon dioxide, CaCO 2, metal chromates, barytes, phthalocyanine green or phthalocyanine blue pigments, red iron oxide, customary stabilizers, carbon black, dyes, clays, epoxidized soybean oil (Paraplex G-62), epoxy (Epon828), tricresyl phosphate, antioxidants, fungicides, bacteriostats, etc. These ingredients can be added in various amounts so that the elastomers or foams obtained have the desired properties.

The polyurethane elastomers and foams according to the invention can be produced by what is known in the art as a "one-shot" process or by a two-step process. In the latter process, the first stage is production a prepolymer. Modifications are the "semi-prepolymer process" or "quasi-prepolymer process". It will the total amount or only part of the polyol reacted with the total amount of the organic polyisocyanate, with a react

- 15 509844/1020

tion product arises that has a high proportion of free isocyanate groups contains and then with the remaining part of the hydroxyl-capped polyol or a crosslinker and with Water, catalysts and metal oxides are reacted to produce a rubbery, cellular, elastic product.

In the method according to the invention, the gel analyzer and the blowing catalyst in a ratio of 0.01 to 5 parts by weight, for example 1 part by weight of the former per part by weight of the latter may be present. In a preferred embodiment in which tin (II) -2-ethylhexoate is used as the blowing catalyst is used as a gel catalyst, the ratio is approximately 1.

The catalyst mixture is preferably in catalytic amounts corresponding to 0.01 to 5 parts by weight, for example 0.6 Parts by weight, per 100 parts by weight of polyol present. Preferably is the propellant catalyst in a catalytic amount corresponding to 0.005 to 4.95 parts by weight, for example 0.3 parts by weight, 100 parts by weight each of the polyol and the gel catalyst present in catalytic amounts corresponding to 0.005 to 4.2 parts by weight, for example 0.3 parts by weight, per 100 parts by weight of polyol.

example 1

According to a specific embodiment, a typical one-shot flexible polyether foam is made by (a) 200 g of polymeric polyether polyol (the polyether triol obtained by the condensation of glycerol and propylene oxide, has a molecular weight of about 3,000, a hydroxyl number of approximately 32-33 and sold under the trademark Niax Polyol 32-33); (b) 3.0 grams of silicone cell modifier (Union Carbide Chemical Co. L-540, designation for a trimethyl-capped dimethylpolysiloxane); (c) 42 g of a mixture of 60 % tolylene diisocyanate (80 % 2,4- and 20 % 2,6-isomer) and 40 % polymethylene-polyphenyl-

- 16 ^; 509844/1020

isocyanate (d) 0.8 g of bis (dimethylaminoethyl) ether; (e) 5.0 g Bis (o-aminophenylthio) methane crosslinking agents; (f) 0.2 g cyclic triethylenediamine; and (g) 2.6 grams of deionized water mixes.

In all examples, the components of the batch were vigorously agitated while mixing. The reaction started immediately, which was indicated by foaming. The cellular polyurethane product foamed and gelled promptly. The rise time and also the time it took for the foam to rise to its maximum height was recorded. The exothermic reaction was measured by placing a thermometer in the foam and measuring the highest temperature. Immediately after the mass had foamed, the surface was scratched with a spatula. This happened at intervals of 5 seconds. The gel time was the time at which the material no longer flowed into one another after scratching. The gel and rise times obtained by these experiments agree well with those obtained in commercial practice. The results were that a superior work-hardened foam was obtained .

- 17 - 509844/102 0 '

Example 2

The procedure of the above example was used except that the composition was made from a mixture of the following components:

(a) 100 parts of polyalkylene polyol (the polyether triol that is produced by Condensation of glycerin and propylene oxide is formed, a molecular weight of approximately 3,000, a hydroxyl number of approximately 56 and under the trademark NIAX TRIOL LG-56 from Union Carbide Chemicals Company or as GP 3030 sold by Wyandotte Chemical Company);

(b) 1.5 parts silicone cell modifier (Union Carbide Chemical Co. L-540, designation for a trimethyl-capped dimethylpolysiloxane);

(c) 45.0 parts of tolylene diisocyanate (80 % 2,4- and 20 % 2,6-isomer);

(d) 3.5 parts deionized water;

(e) 0.3 part of N-ethylmorpholine as a foaming agent or blowing catalyst in the specified amount;

(f) 0.3 part of tin (II) octoate as a gel catalyst; and

(g) 0.2 part of bis (o-aminophenylthio) methane as a crosslinking agent.

All parts given in the examples are by weight.

In all examples, all components were stirred vigorously after mixing. The reaction started immediately, which is what expressed in a foaming. After foaming, the compression load deviation became (C.L.D. = compression load deflection)

measured.

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Example 3

An elastic polyurethane foam was made from the following composition:

Components parts

Polyether * .100.0

Silicone ** 1.5

Water 3.5 foaming catalyst as indicated

Tin (II) octoate 0.3

N-ethylmorpholine ■ 0.3

Tolylene diisocyanate 45.0 (80 % 2,4-isomer and 20 % 2,6-isomer)

Organotin gel catalyst 0.6

* Polyether triol made from glycerine and propylene oxide with a molecular weight of approximately 3,000 and a hydroxyl number of about 56, sold under the trademark NIAX TRIOL LG-56.

** Trimethylol-capped dimethylpolysiloxane available under the trademark Union Carbide L-540 is distributed.

In each case the polyether, the polyisocyanate and the other components were mixed at the same time. The mixtures were allowed to react without external heating. The rise time, i.e. the time it took for the foam to reach its maximum Height was determined and recorded. The gel time, i.e. the time it took to mix was no longer flowable was also arrested.

The first catalyst used for comparison was the foaming catalyst triethylenediamine (distributed as Dabco 33-LV by Houdry).

Tin (II) -2-ethylhexoate and tin (II) oleate are typical gelling catalysts, which are usually prepared by neutralizing an aqueous solution of a tin (II) salt

- 19 509844/1020

with a soap of the desired acid, RCOOH. Typically, an aqueous solution of stannous chloride is combined with a solution reacted by sodium octoate to produce the compound stannous octoate, a typical example of such materials, which should have the formula Sn (OCOR) ρ.

Similarly, selected reactions were carried out using other polyols, e.g. special using a polyester of adipic acid having a hydroxyl number of 52, which is available under the trademark FOAMREZ-50 sold by Witco Chemical Company. '

Comparative polyurethane foams were made using only N-ethylmorpholine as the blowing or foaming catalyst manufactured. The foams produced according to the invention have exceptional physical properties and an exceptional grip, a fact attributed at least in part to the excellent balance that prevails between the competing gelation and foaming reactions. Because of the surprisingly high effectiveness of the mixed diorganotin ester catalysts, the foams may contain minor amounts of catalyst residue. The stability in dry heat and the aging properties are better than known foams. Consequently the foams according to the invention have a wide range of applications. The foam made according to the invention has extraordinary physical properties - such as freedom from splits and closed cells. Similar Results can be obtained when using mixed organotin ester catalysts of the invention can be used.

The compositions of the invention which are suitable for use as crosslinking catalysts in the manufacture of polyurethane foams suitable, being a substance with by the Zerewitinoff method determinable active hydrogen atoms, such as a polyalkylene polyol, water and an organic

- 20 509844/1020

polyfunctional isocyanates are reacted with one another, can be a gel catalyst, a blowing catalyst and at least one compound of the formula

S-R-S

contain, wherein R is hydrocarbon and 'R' is Is hydrogen, halogen or hydrocarbon.

The new compositions are odorless, complete catalysts for polyurethane production. The new polyurethane foams, obtained by the process of the present invention are more widely used than before known polyurethane foams.

The new cellular polyurethane compositions, which according to the Invention are produced, for example, cellular polyurethanes, which is a gelling agent and, as a synergistic propellant combination, 0.004-4.5 parts by weight per 100 parts by weight Polyurethane composition of at least one compound of the formula

NH ₂ NH ₂

S-R-S

contain, wherein R stands for hydrocarbon and R ^{f stands} for hydrogen, halogen or hydrocarbon.

The new cellular polyurethane compositions can be easily molded into foamed cellular polyurethane articles, which are used in the manufacture of upholstery, insulation and other objects where cellular polyurethane

. - 21 -

509844/1020

settings have been used so far.

The curing agent can be mixed with a polyisocyanate prepolymer and the composition can be used at room temperature or are cured slightly elevated temperature, whereby an elastic, tough, rubber-like elastomer is formed.

The one used with the new hardener as described above liquid polyisocyanate prepolymer consisted of the reaction product of (1) polytetramethylene ether glycol (PTMEG, manufactured by Quaker Oats Company) and (2) an 80:20 mixture of 2,4- and 2,6-tolylene diisocyanate, with the molar ratios 1: 2 were.

The polymeric polyols used to make the isocyanate-capped Prepolymers can be used, for example, polyalkylene ether glycols, polyalkylene / arylene ether glycols, hydroxy-terminated polyesters such as polyethylene adipate, Polyethylene sebacate, etc. The polyol can be represented by the formula HO (RO) H, where R is either an alkylene radical with up to 10 carbon atoms or a molecule containing an alkylene-arylene-ester group and η a sufficiently high integer that the molecular weight of the polymeric polyol is about 400 to 6,000.

A wide variety of organic diisocyanates can be used to make the polyisocyanate prepolymer. Suitable compounds are: 2,4-tolylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, 3,3'-dimethyl-4,4-biphenylene diisocyanate, 4,4'-methylene bis (phenyl isocyanate) and the like.

Comparative physical properties of urethane elastomers, those with hardeners and MOCA (4,4'-methylene-bis (2-chi or ο-aniline)) are cured are given in Table I.

- 22 - 50984 4/1020

TABLE I.

CD NJI

Hardening agents Φ CU working time φ φ ίο
• Η
W OvI
Φ Θ ι
O)
TJ * ι
CQ I
• Η tO
Φ · Η hO ίπ-Ρ <Η · Ρ ϋ CQ ttO U-P-P BO O U • Η Ö β W-H O) O CO ffi 3 Φ W) Φ 3
ttJ ö • Η Φ Φ Bis (o-aminophenylthio) - 21.5 20 min at 25 ° C 75 557 570 380 1,2-propane Bis (o-aminophenylthio) - 38.6 60 min at 25 ° C 75 (D) 318 230 930 1,2-propane Bis (o-aminophenylthio) - 22nd 25 min at 25 ° C 83 324 340 490 1,2-propane Bi s (o-aminophenylthio) - 21.6 20 min at 25 ° C _— 266 570 190 1,2-propane Bis (o-aminophenylthio) - 11.6 20 min at 25 ° C __ 312 570 180 1,2-propane Bi s (o-aminophenylthio) -
ethane 20.5 25 min at 25 ° C 75 comparable to example 2 Bis (o-aminophenylthio) - 19.4 30 min at 25 ° C 85 comparable mil methane : Example 2

Example 4

A 500 ml three-necked flask equipped with a mechanical stirrer and a reflux condenser was charged with 125 g (1 mole) of 2-aminobenzenethiol (2-ABT). With good stirring and cooling, a solution of 40 g (1 mole) sodium hydroxide in 60 g water was slowly added over a period of 5 to 20 minutes. The addition was adjusted so that the reaction temperature did not exceed ⁰ 95-10O C. 50 g (0.9O6 mol) of ethylene dichloride were added to the above sodium 2-aminobenzenethiol solution (Na-2-ABT) over a period of 3 hours at a pot temperature of 90-95 ° C. After the addition had ended, the mixture was kept at 100-105 ° C. for a further 4 hours. 200 ml of water were then added with stirring over a period of a few minutes, whereupon phase separation took place. The aqueous salt solution was discarded and the organic layer was washed 2 times with 100 ml of water and under reduced pressure of 25 mm up to a pot temperature of 130 ⁰ C is distilled. The distillation residue was filtered while hot to remove the residual salt. The filtrate, which weighed 274.7 g (99 % of the theoretical yield) was a yellowish white solid which was recrystallized 3 times from methanol, a white solid with a mp of 75.5-76.5 ° C. being obtained.

analysis

C. % C. 14 ^H. 16 ^N 2 ^S 2 % S. (by difference) 60 , 86 H % N , 10 23, 21 calculated 60 , 62 5 , 79 10 , 99 23, 57 found 5 , 82 9 Example 3

Following the procedure of Example 4, using 1,4-dichlorobutane (64.5 g, 0.507 mol) in place of ethylene dichloride a product having a light brown color was obtained as a low viscosity liquid. The yield

- 24 509844/1 020

was more than 95 % of theory. If this hardener was cured with an equivalent weight of polyisocyanate prepolymer with an amine equivalent weight of 650, then a product with a Shore hardness of 73 and a working time of more than 20 minutes was obtained.

Example 6

Following the procedure of Example 4, using 1,4-dichlorobutene-2 instead of ethylene dichloride, a product having a melting point of 64 ° -68 ° C. (theoretical yield 98.5 %) was obtained.

analysis

C. % C. 16 ^H. 18 ^N 2 ^S 2 % S. (by difference) 63, 57 H % N , 24 21 , 21 calculated 65, 41 5 , 98 9 , 76 19th , 77 found 6th , 06 8th

23 parts of this hardener were carefully mixed with 100 parts of polyisocyanate prepolymer (Amine equivalent weight 650) mixed. A polyurethane elastomer with excellent physical properties was used Properties preserved.

Example 7

Following the procedure of Example 4, using bis (2-chloroethyl) ether instead of ethylene dichloride Product obtained in 80.5% yield. It was a brown liquid of low viscosity. 23 parts of this hardener were carefully mixed with 100 parts of polyisocyanate prepolymer (amine equivalent weight 650), being a polyurethane elastomer with excellent physical properties.

Example 8

Following the procedure described in Example 4 were

- 25 509844/102 0,

75 g of 1j2,3-trichloropropane (0.508 mol) were added to a solution of Na-2-ABT (1.5 mol) over a period of 1.5 hours at a pot temperature of 80-85 ° C. The mixture was further reacted at 16 st 100-110 ⁰ C. 187 g (90.5 % yield) of a brown, low viscosity liquid was obtained after cleaning. If this hardener was hardened with polyisocyanate prepolymer (equivalent weight 650), then a product with a Shore Α hardness of 55-60 was obtained. The working time was approximately 30 minutes at room temperature.

Example 9

When 140 g (0.502 moles) of chloromethylated diphenyl oxide (Dow Chemical's CMDPO-25) was substituted for ethylene dichloride following the procedure of Example 4, 215.5 g (97 % yield) of a soft yellow solid composition was obtained. A hard urethane elastomer having excellent physical properties could also be obtained therefrom.

Example 10

An adduct with the following structure was made:

OH

Il I Cl CHa - CHa - 0 - C - N-

NC-OCH ₂ CH ₂ Cl

I I -

H 0

by adding 67 g (0.83 mol) of distilled ethylene chlorohydrin to 69 g (0.39 mol) of 2,4-tolylene diisocyanate and reacting the mixture at 85-90 ° C. for 1.5 hours. The crude product (100 % yield) was crystallized once from benzene to give crystals with a mp of 93-95 ° C.

50.3 g (0.15 mol) of that prepared according to the above procedure

- 26 509844/1020

Adducts were reacted with 0.316 mol of Na-2-ABT solution at a temperature of 110-114 ° C. for 3 hours, 74.5 g (97 % yield) of a viscous hardener being obtained. The amine equivalent weight was 268 (theory 256). 27 parts of this compound were carefully mixed with 65 parts of polyisocyanate prepolymer (650 equivalent weight). The product obtained had a Shore Α hardness of 85 and a working time of more than 50 minutes.

Example 11

An adduct of the following structure was made:

η it 'HO

Un im

fi I '"

ClCH ₂ -CH ₂ -OCN HO. OH NCO-CH ₂ -CH ₂ Cl

(-CH ₂ -CH ₂ -CH ₂ -C

by 130 g (0.2 mol) of polyisocyanate prepolymer and 19 g (0.223 equivalents) of ethylene chlorohydrin were reacted at 85-90 ⁰ C for 4 st. A solution of Na-2-ABT (0.106 mol) was mixed with a solution of 73 g (0.05 mol) of the above product in 50 ml of toluene and refluxed for 3 hours at 94-98 ° C. The product obtained was a light brown, viscous, resinous composition weighing 75.5 g (92.5 % yield). It had an amine equivalent weight of 1015. If this hardener was cured with an equivalent weight of polyisocyanate prepolymer (amine equivalent weight 650), then a product with a Shore Α hardness of 55 was obtained. The working time was better than 1 hour.

Example 12

Following the procedure of Example 4, using 200 g (1.07 mol) of 1,2-bis (2-chloroethoxy) ethane instead of ethylene dichloride, a dark brown liquid was obtained in a yield of 363 g (99 % of theory). The fluid had a Brookfield viscosity of 750 cps at 25 ° C 20 parts

- 27 509844/1020

of this hardener were carefully mixed with 100 parts of polyisocyanate prepolymer (amine equivalent 650). A mixture was obtained that had a pourable consistency and was at 23 ° C
had a working time of 25 minutes. This is to be compared with an equivalent evaluation obtained when mixing powdered MOCA (4,4'-methylene-bis (2-chloroaniline)). The working time is 10 minutes at 65 ° C both
Products showed comparable tensile properties, but with
the curing agent of Example 12 above was found to have an elongation at break of 560 % compared to that of 350 %
obtained with MOCA.

- 28 509 844/1020

Claims (44)

PATENT CLAIMS: *> Process for the production of a highly elastic cellular polyurethane, characterized in that a polyalkylene polyol with reactive hydrogen atoms which can be determined by the Zerewitinoff process, an organic polyfunctional isocyanate, water and a gel catalyst are reacted with one another, the reaction in the presence of a blowing catalyst and a crosslinking agent the formula ' NH ₂ S-R-S wherein R is hydrocarbon and R ^{1 is} hydrogen, halogen or hydrocarbon. 2. The method according to claim 1, characterized in that R ^{1 represents} hydrogen. 3. The method according to claim 2, characterized in that R is alkyl. 4. The method according to claim 1, characterized in that at least one crosslinking agent from bis (o-aminophenylthio) · methane. 5. The method according to claim 1, characterized in that at least one crosslinking agent from bis (o-aminophenylthio) · Ethane exists. 6. The method according to claim 1, characterized in that at least one crosslinking agent from bis (o-aminophenylthio) · 1,2-propane consists. - 29 509844/1020 7. A method for producing a highly elastic cellular polyurethane according to claim 1, characterized in that that the crosslinking agent is a combination of at least one tertiary amine and at least one compound the formula S-R-S wherein R represents hydrocarbon and R 'represents hydrogen, halogen or hydrocarbon. 8. The method according to claim 7, characterized in that N-ethylmorpholine is used as the tertiary amine. 9. The method according to claim 1, characterized in that a compound of the formula Sn (OCOR) ρ or R ¹ _{SnX b is} used as the gel catalyst, in which R and R ^{1 are} hydrocarbon radicals and X is chloride or the negative radical of an organic carboxylic acid, of a mercaptide, an alcohol or an ester of a mercapto acid and a and b are 1-3 and a plus b is 4. 10. The method according to claim 1, characterized in that a catalytic amount of 0.001-5 %, based on the polyol, is used. 11. A process for the production of a highly elastic cellular polyurethane, characterized in that 100 parts of a substance with determinable by the Zerewitinoff process active hydrogen atoms, 5-300 parts of organic polyfunctional isocyanate, 0.5-10 parts of water, 0.005-4.2 Parts of gel catalyst and, as blowing agent catalyst, 0.005 to 4.95 parts of at least one tertiary amine and a crosslinking agent of the formula ■ · - 30 -509844 / 1020 S-R-S R ¹ R in which R is hydrocarbon and R ^{1 is} hydrogen, halogen or hydrocarbon. 12. Process for the production of a highly elastic cellular Polyurethane, characterized in that 100 parts of a substance by the Zerewitinoff process determinable active hydrogen atoms, 5-300 "parts of a organic polyfunctional isocyanate, 0.5-10 parts water, 0.005-4.2 parts gel catalyst, 0.005-4.95 parts a blowing catalyst and as a crosslinking agent combination 0.005-4.95 parts of a mixture of a tertiary Amine and a compound of the formula NH ₂ S-R-S where R is alkyl and R 'is hydrogen, implements. 13. A method for producing a highly elastic cellular polyurethane, characterized in that a substance with determinable by the Zerewitinoff process active hydrogen atoms, an organic polyfunctional isocyanate, water, a gel catalyst and as a blowing agent 0.005-4.95 parts of a mixture with 40 % at least one compound of the formula NH ₂ S-R-S R » - 31 509844/1 020 where R is hydrocarbon and R ^{1 is} hydrogen, halogen or hydrocarbon. 14. Composition that acts as a curing and crosslinking agent suitable in the production of polyurethane foams, an organic compound with by the Zerewitinoff process determinable reactive · hydrogen atoms, water and a polyfunctional isocyanate implemented is, characterized in that the composition is a compound of the formula JHa S-R-S R ¹ wherein R stands for hydrocarbon and R ^{1 stands} for hydrogen, halogen or hydrocarbon, and contains tin (II) -2-ethyl-hexanoate. 15. Composition used as a crosslinking agent in the manufacture of highly resilient cold-curing polyurethane foams suitable, wherein an organic compound with determinable by the Zerewitinoff method reactive Hydrogen atoms, water and an organic polyisocyanate are reacted, characterized in that the composition at least one compound of the formula NH ₂ NH ₂ S ^- -RS R ¹ "R» wherein R stands for hydrocarbon and R ^{1 stands} for hydrogen, halogen or hydrocarbon, and contains at least one tertiary amine. - 32 509844/1020 16. Composition according to claim 15, characterized in that that the tertiary amine consists of N-ethylmorpholine. 17. Composition according to claim 15, characterized in that that the tertiary amine consists of cyclic triethylenediamine. 18. Composition according to claim 15, characterized in that R ^{1 represents} hydrogen. 19. Composition according to claim 18, characterized in that that R stands for alkyl. 20. Composition for use as a crosslinking and curing catalyst in the manufacture of cellular Polyurethane, characterized in that it contains at least one compound of the formula S-R-S R · R « contains, wherein R and R ^{1 are} hydrocarbons selected from alkyl, alkenyl, cycloalkyl, aryl, alkaryl and aralkyl, the composition also containing a compound of the formula Sn (OCOR) ₂ or R ' _{a SnX b as an} auxiliary catalyst, where R and R ^f stand for hydrocarbon radicals and X stands for chloride or the negative radical of an organic carboxylic acid, a mercaptide, an alcohol or an ester of a mercapto acid, a and b stand for 1-3 and a plus b is 4. , _S suitable as a fuel and gel catalyst in the production of polyurethane foams by reaction of a substance determinable by the Zerewitinoff method, active hydrogen atoms, an organic polyfunctional isocyanate and water 21. A catalyst composition -. 33 - 509844/1020 characterized in that it consists of a curing combination of a tertiary amine and a nitrogen-containing one organic compound of the formula R-R-S R ¹
where R is hydrocarbon and R ^{1 is} water substance, halogen or hydrocarbon is. 22. Catalyst composition according to claim 20, characterized in that that the curing catalyst and the blowing catalyst in a ratio of 0.01 to 5 parts of the the former are each part of the latter. 23. Cellular polyurethane composition, characterized in that that it consists of a cellular polyurethane which, as a gelling and hardening agent, is a mixture of at least a tertiary amine and a nitrogen-containing organic compound of the formula S-R-S wherein R is hydrocarbon and R ^{1 is} hydrogen, halogen or hydrocarbon. 24. The composition according to claim 23, characterized in that the nitrogen-containing organic compound consists of bis (o-aminophenylthio) methane consists. ■ 25. The composition according to claim 23, characterized in that the nitrogen-containing organic compound of bis (o-aminophenylthio) ethane consists. - 34 509844/1020 26. The composition according to claim 23, characterized in that the nitrogen-containing organic compound of bis (o-aminophenylthio) -1,2 ~ propane consists. 27. A molded cellular polyurethane article characterized in that that it consists of a cellular polyurethane that contains a gelling agent and a crosslinking agent, -as well as a mixture of a tertiary amine and a nitrogen-containing organic compound of the formula S-R-S wherein R is hydrocarbon and R ^{1 is} hydrogen, halogen or hydrocarbon. 28. Process for the production of an elastomeric polyurethane plastic, characterized in that an organic polyisocyanate with a mixture of an organic Connection with reactive hydrogen atoms determinable by the Zerewitinoff method and with a Molecular weight of at least 500 with at least one compound of the formula NH ₂ S-R-S where R stands for hydrocarbon, mixes, 29. Process for the production of an elastomeric cellular polyurethane, characterized in that one contains a substance with active hydrogen atoms which can be determined by the Zerewitinoff method, an organic polyfunctional isocyanate and at least one curing agent of the formula - 35 509844/1020 SG NH ₂ S-R-S where R is hydrocarbon. 30. The method according to claim 29, characterized in that R stands for alkyl. 31. The method according to claim 29, characterized in that bis (o-aminophenylthio) methane is used as the hardener will. 32. The method according to claim 29, characterized in that a tertiary amine is used as curing agent. 33. The method according to claim 29, characterized in that a cyclic triethylenediamine is used as the hardening agent will. 34. The method according to claim 29, characterized in that a metal soap is used as the hardening agent. 35. The method according to claim 29, characterized in that dibutyltin dilaurate is used as the hardening agent. 36. The method according to claim 29, characterized in that the curing agent consists of an organic compound of the formula R ', SnX', wherein R ^{1 is a} hydrocarbon and X ^{1 is} a negative radical of an organic carboxylic acid, a mercaptan, an alcohol, a Phenol or a halogen acid. 37. Process for the production of an elastomeric polyurethane plastic, characterized in that an organic compound can be determined by the Zerewitinoff method reactive hydrogen atoms and with a molecular weight of at least 500 and an organic poly- - 36 509844/1 020 isocyanate to form a prepolymer and this prepolymer by mixing with at least one Curing catalyst of the formula NH ₂ S-R-S where R is hydrocarbon, cures. 38. Manufacture of an elastomeric polyurethane plastic by a method in which an organic compound can be determined by the Zerewitinoff method reactive hydrogen atoms and an organic Polyisocyanate is reacted, characterized in that at least one compound of the curing agent formula S-R-S wherein R is hydrocarbon is used. 39. Process for the production of an elastomeric polyurethane, characterized in that one has an organic Combination with reactive hydrogen atoms that can be determined by the Zerewitinoff method and an organic one Polyisocyanate in the presence of at least one compound of the formula JH ₂ NH ₂ S-R-S . - 37, -509844 / 1020 where R is hydrocarbon. 40. A method for producing a water-impermeable cellular polyurethane, characterized in that one 100 parts by weight of a substance with determinable by the Zerewitinoff method active hydrogen atoms, 5 to 50 parts by weight of an organic polyfunctional isocyanate and 0.001 to 10 parts by weight of at least one Crosslinking agent of the formula S-R-S where R is hydrocarbon. 41. Composition that can be used in manufacture of water-impermeable polyurethane foams, with a fabric using the Zerewitinoff process determinable active hydrogen atoms, an organic polyfunctional isocyanate and water implemented are, characterized in that they have a blowing catalyst which contains about 1-2 parts by weight of cyclic triethylenediamine and contains approximately 3 parts by weight of N-ethylmorpholine, a gel catalyst and at least one crosslinking agent the formula S-R-S where R is hydrocarbon. 42. Catalytic composition suitable for manufacture of an elastomeric polyurethane, characterized in that it has a substance with through the Zerewiti- - 38 509844/1020 Active hydrogen atoms that can be determined by the noff method, an organic polyfunctional isocyanate and at least one compound of the formula S-R-S where R is hydrocarbon. 43. Composition for use in curing polyurethane by reacting an organic compound with reactive hydrogen atoms that can be determined by the Zerewitinoff method and a polyfunctional isocyanate, characterized in that it contains at least one compound of the formula NH ₈ NH ₂ S-R-S where R is hydrocarbon. 44. Composition for the production of polyurethane foams by reacting a substance with by the Zerewitinoff process determinable active hydrogen atoms, of a polyfunctional isocyanate and water, characterized in that it is 1 part of a blowing catalyst and 0.0001 to 5 parts by weight of a gel catalyst of the formula NH ₂ NH ₂ S-R-S where R is hydrocarbon. - 39 509844/1 020