GB2197657A - Polyurethane sealant compositions employing low molecular weight graft polymer dispersions - Google Patents

Abstract

Polyurethane sealant compositions are prepared by reacting (a) a low molecular weight graft polymer dispersion, (b) a polyether polyol, optionally pigment, catalyst and inorganic filler, and an organic polyisocyanate. The compositions are useful as thermal break sealants and in the manufacture of bowling balls. The graft polymer dispersion is prepared by polymerizing in the presence of a free radical initiator from 25 to 70% wt based on the total weight of the dispersion, an ethylenically unsaturated monomer(s) in a polyol mixture comprising (1) 25 to 99% wt of a polyol having 2 to 8 hydroxyl groups and an equivalent weight of 30 to 200, and (2) 1 to 75% wt of a macromer comprising the reaction product of a polyether polyol having an equivalent weight of 100 to 10,000 and a compound having both ethylenic unsaturation and a group selected from hydroxyl, caboxyl, anhydride, isocyanate and epoxy groups or mixtures thereof.

Description

POLYURETHANE SEALANT COMPOSITIONS EMPLOYING LOW MOLECULAR WEIGHT GRAFT POLYMER DISPERSIONS Background of the Invention 1. Field of the Invention This invention pertains to the preparation of noncellular polyurethane sealant compositions containing low molecular weight graft polymer dispersions.

2. Description of the Prior Art Those skilled in the art know that polyurethane sealant compositions can be prepared by mixing a polyol with an inorganic filler and reacting the mixture with a polyisocyanate. U. S. Patents 3,450,653 and 3,484,517 are two examples of patents which disclose this teaching. The sealants disclosed in the prior art, however, have limited utility because their physical properties, such as tensile strength, hardness, brittleness, heat distortion, impact strength, and shrinkage resistance, have values which, although desirable for some uses, make them undesirable for other uses.

U.S. Patents 4,588,803 and 4,605,725 disclose the use of alkylene oxide adducts of toluenediamine and monoethanolamine for the preparation of sealant compositions.

U.S. Patents 4,568,705 and 4,522,976 disclose the preparation of low molecular weight graft polymer dispersions and products prepared therefrom. There are no teachings that low molecular weight graft polymer dispersions would result in sealant compositions exhibiting increased Shore D hardness and tensile strength.

Summary of the Invention Polyurethane sealants disclosed in the prior art have limited utility because one or more of their properties, such as tensile strength, hardness, brittleness, heat distortion, impact strength, and shrinkaqe have values which, although desirable for some uses, make them undesirable for other uses. This problem was solved by developing a polyurethane sealant composition prepared by (a) reacting a low molecular weight graft polymer dispersion,(b) a polyoxyalkylene polyether polyol, (c) optionally pigment, catalyst, and inorganic filler, and (d) an organic polyisocyanate.

The polyurethane sealants thus prepared have good impact and high tensile strength characteristics.

They can be used for patching floors and roads, to make castings of wheels and rollers, as heat barriers in the manufacture of metal windows and door frames, and in the manufacture of bowling balls.

Description of the Preferred Embodiments The polyurethane sealants which are the subject matter of this invention are prepared by reacting a mixture of (a) a graft polymer dispersion prepared by polymerizing in the presence of a free radical initiator from about 25 to about 70 weight percent based on the total weight of the dispersion, an ethylenically unsaturated monomer or mixture of monomers, in a polyol mixture comprising (1) from about 25 to about 90 weight percent of a polyol containing from 2 to 8 hydroxyl groups and having an equivalent weight from 30 to about 200, and 0 (2) from about 1 to about 75 weight percent of a macromer containing induced unsaturation, said macromer comprising the reaction product of a polyether polyol having an equivalent weight from 100 to 10,000 with a compound having both ethylenic unsaturation and a group selected from the group consisting of a hydroxyl, carboxyl, anhydride, isocyanate, and epoxy group or mixtures thereof, (b) a polyoxyalkylene polyether polyol selected from the group consisting of an ethylene oxide adduct of toluenediamine having a molecular weight range from about 300 to about 700, an ethylene oxide propylene oxide adduct of monoethanolamine having a molecular weight range from about 200 to about 500, and a polyoxyalkylene polyether polyol other than one derived from an amine, having an equivalent weight from about 100 to about 750, and mixtures thereof, (c) optionally pigment, catalyst, and inorganic filler, and (d) an organic polyisocyanate.

In accordance with the subject invention, a low viscosity, stable graft polymer dispersion is prepared by polymerizing in the presence of a free radical initiator, from about 25 to about 70 weight percent based on the total weight of the dispersion, an ethylenically unsaturated monomer or mixture of monomers, in a polyol mixture comprising (1) from about 25 to about 99 weight percent of a polyol containing from 2 to 8 hydroxyl groups and having an equivalent weight from 30 to about 200, (2) from about 1 to about 75 weight percent of a macromer containing induced unsaturation, said macromer comprising the reaction product of a polyether polyol having an equivalent weight from 100 to 10,000 with a compound having both ethylenic unsaturation and a group selected from the group consisting of a hydroxyl, carboxyl, anhydride, isocyanate and epoxy or mixtures thereof.

The polyols which are contemplated in the practice of this invention contain from 2 to 8 hydroxyl groups and have an equivalent weight ranging from about 30 to about 200. These include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, l,4-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7 heptanediol, glycerol, l,l,l-trimethylolpropane, 1,1,1trimethylolethane, l,2,6-hexanetriol, a-methyl glucoside, pentaerythritol, sorbitol and sucrose. Also included within the term polyol are compounds derived from phenol such as 2,2-bis(4-hydroxyphenyl)propane, commonly known as Bisphenol A.

Also included are the halogenated glycols such as mono-, di-, and trichloro-ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol and other halogenated glycols. ln the event that the normally solid polyhydric compounds are not liquid at the reaction temperatures which are contemplated, mixtures of the above may be employed.

As mentioned above, the polyol comprises from about 25 to about 99 weight percent of the polyol mixture comprising the polyol and the macromer.

Representative polyols essentially free from ethylenic unsaturation which may be employed in the preparation of the macromers of the invention are well known to those skilled in the art. They are often prepared by the catalytic condensation of an alkylene oxide or mixture of alkylene oxides either simultaneously or sequentially with an organic compound having at least two active hydrogen atoms, such as evidenced by U.S. Patent Nos. 1,922,459, 3,190,927, and 3,346,557. Representative polyols include polyhydroxyl-containing polyesters, polyoxyalkylene polyether polyols1 polyhydroxy-terminated polyurethane polymers, polyhydroxyl-containing phosphorus compounds, and alkylene oxide adducts of polyhydric polythioesters, polyacetals, aliphatic polyols and thiols, ammonia and amines including aromatic, aliphatic, and heterocyclic amines, as well as mixtures thereof.Alkylene oxide adducts of compounds which contain two or more different groups within the abovedefined classes may also be used, for example, amino alcohols which contain an amino group and a hydroxyl group. Also, alkylene oxide adducts of compounds which contain one SH group and one OM group as well as those which contain an amino group and an SH group may be used.

Generally, the equivalent weight of the polyols will vary from 100 to 10,000, preferably from 1000 to 3000.

Any suitable hydroxy-terminated polyester may be used such as are prepared, for example, from polycarboxylic acids and polyhydric alcohols. Any suitable polycarboxylic acid may be used such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid, thapsic acid, maleic acid, fumaric acid, glutaconic acid, a-hydromuconic acid, B-hydromuconic acid, a-butyl-a-ethyl-glutaric acid, a,B-dicthylsuccinic acid, isophthalic acid, terephthalic acid, hemimellitic acid, and 1,4-cyclohexanedi carboxylic acid.Any suitable polyhydric alcohol, includinq both aliphatic and aromatic, may be used such as ethylene glycol, propylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,4pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, glycerol, l,l,l-trimethylolpropane, l,l,l-trimethylol- ethane, l,2,6-hexanetriol, a-methyl glucoside, pentaerythritol, and sorbitol. Also included within the term "polyhydric alcohol" are compounds derived from phenol such as 2,2-bis(4-hydroxyphenyl)propane, commonly known as Bisphenol A.

The hydroxyl-containing polyester may also be a polyester amide such as is obtained by including some amine or amino alcohol in the reactants for the preparation of the polyesters. Thus, polyester amides may be obtained by condensing an amino alcohol such as ethanolamine with the polycarboxylic acids set forth above or they may be made using the same components that make up the hydroxylcontaining polyester with only a portion of the components being a diamine such as ethylene diamine.

Any suitable polyoxyalkylene polyether polyol may be used such as the polymerization product of an alkylene oxide or a mixture of alkylene oxides with a polyhydric compound. Any suitable alkylene oxide may be used such as ethylene oxide, propylene oxide, butylene oxide, amylene oxide, and mixtures of these oxides. The polyoxyalkylene polyether polyols may be prepared from other starting materials such as tetrahydrofuran and alkylene oxide tetrahydrofuran mixtures epihalohydrins such as epichlorohydrin as well as aralkylene oxides such as styrene oxide.The polyoxyalkylene polyether polyols may have either primary or secondary hydroxyl groups. lncluded among the polyether polyols are polyoxyethylene glycol, polyoxypropylene glycol, polyoxybutylene glycol, polytetramethylene glycol, block copolymera, for example, combinations of polyoxypropylene and polyoxyethylene glycols, poly-l,2- oxybutylene and polyoxyethylene glycols, poly-l,4-oxy- butylene and polyoxyethylene glycols, and random copolymer glycols prepared from blends of two or more alkylene oxides or by the sequential addition of two or more alkylene oxides.The polyoxyalkylene polyether polyols may be prepared by any known process such as, for example, the process disclosed by Wurtz in 1859 and Encyclopedia of Chemical Technology Vol. 7, pp. 257-262, published by Interscience Publishers, Inc. (1951) or in U.S. Patent No.

1,922,459. Polyethers which are preferred include the alkylene oxide addition products of trimethylolpropane, glycerine, pentaerythritol, sucrose, sorbitol, propylene glycol, and 2,2'-(4,4'-hydroxyphenylpropane and blends thereof having equivalent weights of from 100 to 10,000.

Suitable polyhydric polythioethers which may be condensed with alkylene oxides include the condensation product of thiodiglycol or the reaction product of a dicarboxylic acid such as is disclosed above for the preparation of the hydroxyl-containing polyesters with any other suitable thioether glycol.

Polyhydroxyl-containing phosphorus compounds which may be used include those compounds disclosed in U.S. Patent No. 3,639,542. Preferred polyhydroxyl-containing phosphorus compounds are prepared from alkylene oxides and acids of phosphorus having a P205 equivalency of from about 72 percent to about 95 percent.

Suitable polyacetals which may be condensed with alkylene oxides include the reaction product of formaldehyde or other suitable aldehyde with a dihydric alcohol or an alkylene oxide such as those disclosed above.

Suitable aliphatic thiols which may be condensed with alkylene oxides include alkanethiols containing one or two -SH groups such as 2-mercaptoethanol, 1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, and 1,6-hexanedi thiol alkene thiols such as 2-butene-1,4-dithiol and alkyne thiols such as 3-hexyne-1,6-dithiol.

Suitable amines which may be condensed with alkylene oxides include aromatic amines such as aniline, ochloroaniline, p-aminoaniline, 1,5-diaminonaphthalene, methylene dianiline, the condensation products of aniline and formaldehyde, and 2,3- 2,6-, 3,4-, 2,5-, and 2,4 diaminotoluene, aliphatic amines such as methylamine, triisopropanolamine, ethylenediamine, 1,3-diaminopropane, 1,3-diaminobutane, 1,4-diaminobutane, and ammonia.

Also, polyols containing ester groups can be employed in the subject invention. These polyols are prepared by the reaction of an alkylene oxide with an organic dicarboxylic acid anhydride and a compound containing reactive hydrogen atoms. A more comprehensive discussion of these polyols and their method of preparation can be found in U.S. Patents Nos. 3,585,185 3,639,541 and 3,639,542.

The unsaturated polyols or macromers which are employed in the present invention may be prepared by the reaction of any conventional polyol such as those described above with an organic compound havinq both ethylenic unsaturation and a hydroxyl, carboxyl, anhydride, isocyanate or epoxy group or they may be prepared by employing an organic compound having both ethylenic unsaturation and a hydroxyl, carboxyl, anhydride, isocyanate or epoxy group as a reactant in the preparation of the conventional polyol.

Representative of such organic compounds include unsaturated mono- and polycarboxylic acids and anhydrides such as maleic acid and anhydride, fumaric acid, crotonic acid and anhy dride, propenyl succinic anhydride, acrylic acid, acryoyl chloride, hydroxy ethyl acrylate or methacrylate and halogenated maleic acids and anhydrides, unsaturated polyhydric alcohols such as 2-butene-1,4-diol, glycerol allyl ether, trimethylolpropane allyl ether, pentaerythritol allyl ether, pentaerythritol vinyl ether, pentaerythritol diallyl ether, and l-butene-3,4-diol, unsaturated epoxides such as l-vinylcyclohexene-3,4-epoxide, butadiene monoxide, vinyl glycidyl ether(l-vinyloxy-2,3-epoxy propane), glycidyl methacrylate and 3-allyloxypropylene oxide (allyl glycidyl ether). If a polycarboxylic acid or anhydride is employed to incorporate unsaturation into the polyols, it is preferable to react the unsaturated polyol with an alkylene oxide, preferably ethylene or propylene oxide, to replace the carboxyl groups with hydroxyl groups prior to employment in the present invention. The amount of alkylene oxide employed is such as to reduce the acid number of the unsaturated polyol to about 5 or less.

The alkylene oxides which may be employed for the preparation of the polyetherester polyols include ethylene oxide, propylene oxide, butylene oxide, amylene oxide and mixtures of these oxides, preferably ethylene and propylene oxide.

Chain transfer agents may be employed as reaction moderators and more particularly at temperatures below 105"C. The polymerization reaction may be carried out at temperatures between 250C and 1800C, preferably between 800C and 1350C. The mixture contains from about 0.001 to 1.0 mole of unsaturation per mole of mixture.

The reaction moderators agents employed will depend on the particular monomers or mixtures of monomers employed and the molar ratios of such mixtures. The concentration of the reaction moderator employed is that amount which is effective and may range from 0.1 to 10 percent by weight based on the weight of monomer, preferably from 0.5 to 2.0 weight percent based on the weight of monomer.

Among those reaction moderators which may be employed are as follows: acetic acid, bromoacetic acid, chloroacetic acid, ethyl dibromoacetate, iodoacetic acid, tribromoacetic acid, ethyl tribromoacetate, trichloroacetic acid, ethyl trichloroacetate, acetone, p-bromophenylacetonitrile, p-nitrophenylacetylene, allyl alcohol, 2,4,6trinitroaniline, p-ethynylanisole, 2,4,6-trinitroanisole, azobenzene, benzaldehyde, p-cyanobenzaldehyde, 2-butylbenzene, bromobenzene, l,3,5-trinitrobenzene, benzochrysene, ethyl trinitrobenzoate, benzoin, benzonitrile, benzopyrene, tributylborane, 1,4-butanediol, 3,4-epoxy-2-methyl-l-butene, t-butyl ether, t-butyl isocyanide, l-phenylbutyne, p-cresol, p-bromocumene, dibenzonaphthacene, p-dioxane, pentaphenyl ethane, ethanol, l,l-diphenylethylene, ethylene glycol, ethyl ether, fluorene, N,N-dimethylformamide, 2-heptene, 2hexene, isobutyraldehyde, diethyl bromomalonate, bromotrichloromethane, dibromoethane, diiodomethane, naphthalene, 1naphthol, 2-naphthol, methyl oleate, 2,4,4-triphenyl-lpentene, 4-methyl-2-pentene, 2,6-diisopropylphenol, phenyl ether, phenylphosphine, diethylphosphine, dibutylphosphine, phosphorus trichloride, l,l,l-tribromopropane, dialkyl phthalate, 3-phosphinopropionitrile, l-propanol, pyrocatechol, pyrogallol, methyl stearate, tetraethylsilane, triethylsilane, dibromostilbene, a-bromostyrene, -methyl- styrene, tetraphenyl succinonitrile, 2,4,6-trinitrotoluene, p-toluidine, N,N-dimethyl-p-toluidine, -cyano-p-tolu- nitrile, a, '-dibromo-p-xylene, 2,6-xylenol, diethyl zinc, dithiodiacetic acid, ethyl dithiodiacetic acid, 4,4'-dithiobisanthranilic acid, benzenethiol, o-ethoxybenzenethiol, 2,2'-dithiobisbenzothiazole, benzyl sulfide, l-dodecanethiol, ethanethiol, l-hexanethiol, l-naphthalenethiol, 2naphthalenethiol, l-octanethiol, l-heptanethiol, 2-octanethiol, l-tetradecanethiol, a-toluenethiol, isopropanol, 2butanol, toluene, bromochloromethane, l-butanol, carbon tetrachloride, 2-mercaptoethanol, octadecyl mercaptan, carbon tetrabromide and tertiary dodecyl mercaptan.

When the macromer is prepared employing either maleic acid and/or maleic anhydride, the maleated macromer is isomerized at temperatures ranging from 800C to 1200C for one-half hour to three hours in the presence of an effective amount of an isomerization catalyst. The catalyst is employed at concentrations greater than 0.01 weight percent based on the weight of the macromer and may be as high as 5.0 weight percent.

The maleate containing polyetherester polyol may be prepared employing the catalyst selected from the group consisting of salts and oxides of divalent metals, the concentration of catalyst which may be employed ranges from 0.01 to 0.5 weight percent based on the weight of polyol mixture. The temperatures employed range from 750C to 1750C. The equivalent weight of the polyol employed to prepare the macromer may vary from 1000 to 10,000, preferably from 2000 to 6000.

Among the diva lent metals which may be employed are: zinc acetate, zinc chloride, zinc oxide, zinc neodecanoate, tin chloride, calcium naphthenate, calcium chloride, calcium oxide, calcium acetate, copper naphthenate, cadmium acetate, cadmium chloride, nickel chloride, manganese chloride, and manganese acetate.

Certain of the above-mentioned catalysts such as calcium naphthenate promote the isomerization of the maleate to the fumarate structure during the preparation of the ma cromer.

The macromer unsaturation ranges from 0.1 mole to 1.5 mole of unsaturation per mole of polyol and, preferably, from 0.5 to 1.0 mole of unsaturation per mole of polyol.

As mentioned above, the graft polymer dispersions of the invention are prepared by the in situ polymerization, in the above-described mixtures of an ethylenically unsaturated monomer or a mixture of ethylenically unsaturated monomers. Representative ethylenically unsaturated monomers which may be employed in the present invention include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, norbornadiene, 1,7-octadiene, styrene, a-methylstyrene, 2methylstyrene, 3-methylstyrene and 4-methylstyrene, 2,4dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene, benzylstyrene, and the like, substituted styrenes such as cyanostyrene, nitrostyrene, N,N-dimethylaminostyrene, acetoxystyrene, methyl 4-vinylbenzoate, phenoxystyrene, p-vinylphenyl oxide, and the like, the acrylic and substituted acrylic monomers such as acrylonitrile, acrylic acid, methacrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, methyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, isopropyl methacrylate, octyl methacrylate, methacrylonitrile, ethyl a-ethoxyacrylate, methyl a-acetaminoacrylate, butyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, phenyl methacrylate, N,N-dimethylacrylamide, N,N-dibenzyl acrylamide, N-butylacrylamide, methacrylyl formamide, and the like' the vinyl esters, vinyl ethers, vinyl ketones, etc., such as vinyl acetate, vinyl butyrate, isopropenyl acetate, vinyl formate, vinyl acrylate, vinyl methacrylate, vinyl methoxyacetate, vinyl benzoate, vinyltoluene, vinyl naphthalene, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ethers, vinyl butyl ethers, vinyl 2=ethylhexyl ether, vinyl phenyl ether, vinyl 2-methoxyethyl ether, methoxybutadiene, vinyl 2-butoxyethyl ether, 3,4-dihydro-1,2-pyran, 2butoxy-2'-vinyloxy diethyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl phosphonates such as vinyl phenyl ketone, n-vinyl carbazole, vinyl ethyl sulfone, N-methyl-Nvinyl acetamide, N-vinylpyrrolidone, vinyl imidazole, divinyl benzene, divinyl sulfoxide, divinyl sulfone, sodium vinylsulfonate, methyl vinylsulfonate, N-vinyl pyrrole, and the like: dimethyl fumarate, dimethyl maleate, maleic acid, crotonic acid, fumaric acid, itaconic acid, monomethyl i taconate, t-butylaminoethyl methacrylate, dimethylaminoethyl methacrylate, glycidyl acrylate, allyl alcohol, glycol monoesters of itaconic acid, vinyl pyridine, and the like, Any of the known polymerizable monomers can be used and the compounds listed above are illustrative and not restrictive of the monomers suitable for use in this invention.

Preferably, the monomers are acrylonitrile and styrene.

The amount of ethylenically unsaturated monomer employed in the polymerization reaction is generally from about 25 percent to about 70 percent, preferably from 30 percent to 50 percent, based on the total weight of the dispersion. The polymerization occurs at a temperature between about 250C and 1800C, preferably from 8O0C to 1350C.

Illustrative polymerization initiators which may be employed are the well-known free radical types of vinyl polymerization initiators such as the peroxides, persulfates, perborates, percarbonates, azo compounds, etc.

These include hydrogen peroxide, dibenzoyl peroxide1 acetyl peroxide, benzoyl hydroperoxide, t-butyl hydroperoxide, dit-butyl peroxide, lauroyl peroxide, butyryl peroxide, diisopropylbenzene hydroperoxide, cumene hydroperoxide, paramenthane hydroperoxide, diacetyl peroxide, di-a-cumyl peroxide, dipropyl peroxide, diisopropyl peroxide, isopropyl-t-butyl peroxide, butyl-t-butyl peroxide, difuroyl peroxide, bis(triphenylmethyl) peroxide, bis(p-methoxybenzoyl) peroxide, p-monomethoxybenzoyl peroxide, rubene peroxide, ascaridol, t-butyl peroxybenzoate, diethyl peroxyterephthalate, propyl hydroperoxide, isopropyl hydroperoxide, n-butyl hydroperoxide, t-butyl hydroperoxide, cyclohexyl hydroperoxide, trans-decalin hydroperoxide, amethylbenzyl hydroperoxide, a-methyl--ethyl benzyl hydroperoxide, tetralin hydroperoxide, triphenylmethyl hydroper oxide, diphenylmethyl hydroperoxide, a,a'-azobis-(2methyl heptonitrile), l,l'-azo-bisfcyclohexane carbonitrile), 4,4'azobis(4-cyanopentanoic acid), 212'-azobis(isobutyroni- trile), 1-t-butylazo-1-cyanocyclohexane, persuccinic acid, diisopropyl peroxy dicarbonate, 212'-azobis(2,4-dimethyl- valeronitrile), 2-t-butylazo-2-cyano-4-methoxy-4-methylpentane,2,2'-azobis-2-methylbutanenitrile, 2-t-butylazo-2cyanobutane, l-t-amylazo-l-cyanocyclohexane, 2, 2'-azobis- (2,4-dimethyl-4-methoxyvaleronitrile), 2-t-butylazo-2-cyano4-methylpentane, 2-t-butylazo-2-isobutyro-nitrile, to butylperoxyisopropyl carbonate and the like: a mixture of initiators may also be used.The preferred initiators are 2,2'-azobis(2-methylbutanenitrile), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2-tbutylazo-2-cyano-4-methoxy-4-methylpentane, 2-t-butylazo-2cyano-4-methylpentane, and 2-t-butylazo-2-cyanobutane.

Generally, from about 0.01 percent to about 5 percent, preferably from about 0.5 percent to about 1,5 percent, by weight of initiator based on the weight of the monomer will be employed in the process of the invention.

The graft polymer dispersions of this invention have useful viscosities of less than 10,000 cps at 250C.

Preferably they have viscosities ranging from 500 to 2000 cps at 25"C.

The alkylene oxide adduct of monoethanolamine is prepared by reacting ethylene oxide and propylene oxide with monoethanolamine, preferably in the presence of an alkaline catalyst. This catalyst may be potassium hydroxide, sodium hydroxide, sodium and potassium methylate and other catalyst well known to those skilled in the art. The quantity of ethylene and propylene oxide employed is such that the molecular weight of the adduct may vary from about 200 to about 500. The ethylene oxide content may range from about 5 percent to about 50 percent based on the total weight of the adduct.

The ethylene oxide adduct of toluenediamine is prepared by reacting ethylene oxide with toluenediamine, preferably in the presence of an alkaline catalyst. This catalyst may be potassium hydroxide, sodium hydroxide, sodium and potassium methylate and other catalyst well known to those skilled in the art. The quantity of ethylene oxide employed is such that the molecular weight of the adduct may vary from about 300 to about 700.

Inorganic fillers may be employed in an amount which is from 0.15 part to 0.7 part by weight per part of polyether polyol. Inorganic mineral fillers which can be used to mix with the polyether polyols are selected from the group consisting of calcium silicate, aluminum silicate, magnesium silicate, calcium carbonate and mixtures thereof. One of the functions served by the mineral filler is to reduce shrinkage of the sealant.

If too much filler is added, however, the viscosity of the mixture will be too high at room temperature. This will make it difficult to mix the polyol-filler component with the isocyanate component. The temperature of the polyol-filler component can be elevated to temperatures of 50"C to decrease its viscosity and to promote better mixing with the isocyanate component. The viscosity of the polyol-filler component is also dependent upon the filler used. Calcium silicate will provide polyol-filler components with lower viscosities while aluminum silicate and magnesium silicate will provide polyol-filler components with higher viscosities.

The mixture of polyoxyalkylene polyether polyol and graft polymer dispersion is reacted with an organic polyisocyanate such that the ratio of isocyanate groups of the polyisocyanate to the hydroxyl groups of the polyether polyol is from about 1.0:1 to about 1.3::1. Polyisocyanates which may be used include aromatic, aliphatic, and cycloaliphatic polyisocyanates and combinations thereof, Representative examples are diisocyanates such a m-phenylene diisocyanate, 2,4-toluenediisocyanate, 2,6-toluenediisocya- nate, mixtures of 2,4-toluenediisocyanate and 2,6-toluenediisocyanate, hexamethylene diisocyanate, tetrameehylene diisocyanate, 1,4-cyclohexane diisocyanate, hexahydrotoluene diisocyanate, l,5-naphthalene diisocyanatet l-methyoxy-2,4phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, and 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, the triisocyanates such as 4,4'4"-triphenylmethane triisocyanate, polymethylene polyphenylene polyisocyanate and 2,4,6toluene triisocyanatc; and the tetraisocyanates such as 4,4'-dimethyl-2,21,5,5'-diphenylmethane tetraisocyanate.

Especially useful due to their availability and properties are toluene diisocyanate, 4,4'-diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate. Polymethylene polyphenylene polyisocyanate, which is most preferred, is a product which results from the phosgenation of an aniline-formaldehyde condensation product, it is sometimes called "crude or polymeric MDI." As was previously mentioned, catalysts may be used to increase the reaction rate. If catalysts are used, they are added to the mixture of the polyether polyol and graft polymer dispersion and inorganic filler before the reaction of the mixture with the polyisocyanate.

Urethane catalysts which may be employed in the present invention are well known in the art and include the metal or organometallic salts of carboxylic acid and tertiary amines. Representative of such compounds are: dibutyltin dilaurate, dibutyltin diacetate, stannous octoate, lead octoate, cobalt naphthenate, and other metal or organometallic salts of carboxylic acids in which the metal is bismuth, titanium, iron, antimony, uranium, cadmium, aluminum, mercury, zinc, or nickel as well as other organometallic compounds such as are disclosed in U.S, Patent 2,846,408. Tertiary amines such as triethylenediamine, triethylamine, diethylcyclohexylamine, N-ethylmorpholine and diethylethanolamine may also be employed as well as mixtures of any of the above.Generally, the amount of urethane-promoting catalyst employed will be from 0.01 percent to 10 percent by weight based on the weight of the polyether polyol.

Although the polyurethane sealants prepared in accordance with the described process have many uses, they are particularly useful as thermal break barriers when used in the manufacture of metal window and door frames. Other sealants will shrink when they are used for this purpose.

Applicants have found that polyurethane sealants prepared in accordance with this invention are shrink resistant or exhibit very little shrinkage, generally less than 2.5 percent.

Thermal break sealants are utilized as a part of a composite consisting of a sealant, a metal extrusion and window glass. The sealant separates metal sections, one section of which is exposed to the outside of a building and the other section is exposed to indoor conditions. The sealant serves as a less conductive barrier to the transfer of heat from the warm side of the metal composite to the other. Although the sealant was originally used as a gap filler with good insulating properties, the same sealant is now considered as part of the structural component and desirably has good physical properties such as flexural modulus at elevated temperatures and little or no shrinkage.

The compositions of the instant invention have also found applications in the manufacture of bowling balls. In the past, bowling balls have been constructed of one or more natural or synthetic materials. These include such materials as natural rubber, based on cis 1,4-poly- isoprene or synthetic rubber such as neoprene, butadienestyrene, butyl rubber and the like. Other compositions include polyesters prepared from polycarboxylic acid and polyhydric alcohol such as succinic, maleic, fumaric, phthalic, terephthalic and isophthalic acids and polyhydric alcohols such as ethylene glycol, glycerine, butanediol, sorbitol and the like. Mixtures of acrylic polymers and polyester resins may be employed. Other compositions may employ ethylenically unsaturated polyesters reacted with styrene in the presence of an initiator.The composition may contain inorganic fillers such as calcium carbonate, silica, kaolin clays, calcium silicate and the like. Thus, the composition of the bowling ball may comprise the reaction products of the sealant described above It is contemplated that the entire bowling ball may be constructed of the composition described, however, preferably the bowling ball comprises an outer spherical solid body of molded material enclosing a central core of heavier material wherein the outer body comprises the reaction product of the polyether polyol, the graft polymer dispersion and an organic polyisocyanate as previously described.

The properties of the polyurethane sealants in the examples which follow were determined by the following ASTM test methods: Test Method Tensile Strength ASTM D638 Shore D Hardness ASTM D2240 The following abbreviations are employed in the Examples below.

Polyol A is polyoxypropylene glycol having a hydroxyl number of about 110.

Polyol B is a propylene oxide adduct of toluenediamine, 50 percent vicinal isomers of 2,3 and 3,4 having a hydroxyl number of about 450.

Polyol C is polyoxypropylene glycol having a hydroxyl number of about 160.

Polyol D is a ethylene oxide-propylene oxide adduct of trimethylolpropane having a hydroxyl number of 24, an ethylene oxide content of 75 percent and containing about 0.2 moles of fumarate unsatura tion per mole of polyol.

Polyol E is a mixture of Polyol D and propylene glycol in a ratio of about 1:29 Polyol D:propylene glycol reacted with 48 percent 1:2 acrylonitrile:styrene having a hydroxyl number of about 767.

Polyol F is an ethylene oxide-propylene oxide adduct of trimethylolpropane having a hydroxyl number of 25 containing 4.8 percent ethylene oxide which has been reacted with maleic anhydride and capped with propylene oxide and containing about 0.6 moles of fumarate unsaturation per mole of polyol.

Polyol G is a mixture of Polyol F and Polyol C in a ratio of 1:100 Polyol F to Polyol C reacted with 48.8 percent 1:2 acrylonitrile:styrene having a hydroxyl number of about 75.

Polyol H is an ethylene oxide-propylene oxide adduct of monoethanolamine containing 26 percent ethylene oxide having a hydroxyl number of about 500.

TIPA is triisopropanolamine.

Filler A is a 50:50 mixture of castor oil and powdered Type 3A molecular sieve.

Catalyst A is 33 percent triethylenediamine in dipropylene glycol.

Isocyanate A is polymethylene-polyphenylene polyisocyanate.

Examples 1-4 The formulations as shown in Table I, without the isocyanate, were blended together in a suitable container with 0.1 pbw of Dow Corning 290 fluid sold by Dow Corning Corporation and allowed to deaerate by placing the blend in an evacuated Bell jar at 0.1 mm pressure. The indicated amounts of Isocyanate A were added, the mixture agitated for 20 to 80 seconds and then poured into suitable metal molds. The cast sealants were subsequently removed from the molds and allowed to cure for at least seven days. Physical properties of the products were then determined.

TABLE I Example 1 2 3 4 Polyol A, pbw 50 50 45 45 Polyol B, pbw 30 30 TIPA, pbw 10 10 Propylene glycol, pbw - 10 Polyol E, pbw 10 - Polyol G, pbw - - - 10 Polyol C, pbw - - 10 Polyol H, pbw - - 45 45 Filler A, pbw 3.0 3.0 3.0 3.0 Catalyst A1 pbw 0.03 0.03 - Isocyanate A, pbw (125 index) 108.6 123.1 85.0 82.9 Mix Time, sec. 35 35 35 35 Cream Time, n - - - Pour Time, " 202 206 136 140 Gel Time, " 212 217 143 146 Physical Properties Tensile Strength, kPa 66950 49871 32751 35736 Yield Strength, " - - 41694 45645 Elongation, % 3.7 1.7 17.7 18.0 Tear Strength, N/M 103x103 66x103 155xlO 154x103 Hardness, Shore D, inst/5 sec. 84/82 75/73 79/76 81/78

Claims (26)

1. A non-cellular polyurethane composition comprising the reaction product of (a) a graft polymer dispersion prepared by polymerizing in the presence of a free radical initiator from about 25 to abou 70 weight percent based on the total weight of the dispersion, an ethylenically unsaturated monomer or mixture of monomers, in a polyol mixture comprising (1) from about 25 to about 90 weight percent of a polyol containing from 2 to 8 hydroxyl groups and having an equivalent weight from 30 to about 200, and (2) from about 1 to about 75 weight percent of a macromer containing induced unsaturation, said macromer comprising the reaction product of a polyether polyol having an equivalent weight from 100 to 10,000 with a compound having both ethylenic unsaturation and a group selected from the group consisting of a hydroxyl, carboxyl, anhydride, isocyanate, and epoxy group or mixtures thereof, (b) a polyoxyalkylene polyether polyol selected from the group consisting of an ethylene oxide adduct of toluenediamine having a molecular weight range from about 300 to about 700, an ethylene oxide propylene oxide adduct of monoethanolamine having a molecular weight range from about 200 to about 500, and a polyoxyalkylene polyether polyol other than one derived from an amine, having an equivalent weight from about 100 to about 750, and mixtures thereof, (c) optionally pigment, catalyst, and inorganic filler, and (d) an organic polyisocyanate.

2. The graft polymer dispersion of claim 1 wherein the amount of induced saturation is from about 0.001 to about 1.0 mole of unsaturation per mole of polyol mixture.

3. The graft polymer dispersion of claim 1 wherein the monomer is selected from the group consisting of styrene, methylstyrene, vinyl toluene, methyl methacrylate, methacrylonitrile, divinylbenzene and acrylonitrile.

4. The graft polymer dispersion of claim 1 wherein the monomer is selected from the group consisting of styrene and acrylonitrile.

5. The polymer dispersion of claim 1 wherein the monomer is styrene.

6. The polymer dispersion of claim 1 wherein the polymerization occurs in the presence of a chain transfer agent.

7. The polymer dispersion of claim 6 wherein the reaction moderator is selected from the group consisting of dodecanethioli bromotrichloromethane, 2-butanol, l-butanol, allyl alcohol, 2-mercaptoethanol and octadecyl mercaptan.

8. The polymer dispersion of claim 6 wherein the concentration of reaction moderator is from about 0.1 weight percent to about 10 weight percent based on the weight of the monomer.

9. A thermal break composition for use in the manufacture of door frames and windows which comprises a composition prepared by reacting (a) a graft polymer dispersion prepared by polymerizing in the presence of a free radical initiator from about 25 to about 70 weight percent based on the total weight of the dispersion, an ethylenically unsaturated monomer or mixture of monomers, in a polyol mixture comprising (1) from about 25 to about 90 weight percent of a polyol containing from 2 to 8 hydroxyl groups and having an equivalent weight from 30 to about 200, and (2) from about 1 to about 75 weight percent of a macromer containing induced unsaturation, said macromer comprising the reaction product of a polyether polyol having an equivalent weight from 100 to 10,000 with a compound having both ethylenic unsaturation and a group selected from the group consisting of a hydroxyl, carboxyl, anhydride, isocyanate, and epoxy group or mixtures thereof, (b) a polyoxyalkylene polyether polyol selected from the group consisting of an ethylene oxide adduct of toluenediamine having a molecular weight range from about 300 to about 700, an ethylene oxide propylene oxide adduct of monoethanolamine having a molecular weight range from about 200 to about 500, and a polyoxyalkylene polyether polyol other than one derived from an amine, having an equivalent weight from about 100 to about 750, and mixtures thereof, (c) optionally pigment, catalyst, and inorganic filler, and (d) an organic polyisocyanate.

10. The composition of claim 9 wherein the organic polyisocyanate is polymethylene polyphenylene polyisocyanate.

11. A process for preparing a low shrinkage polyurethane sealant composition comprising reacting (a) a graft polymer dispersion prepared by polymerizing in the presence of a free radical initiator from about 25 to about 70 weight percent based on the total weight of the dispersion, an ethylenically unsaturated monomer or mixture of monomers, in a polyol mixture comprising (1) from about 25 to about 90 weight percent of a polyol containing from 2 to 8 hydroxyl groups and having an equivalent weight from 30 to about 200, and (2) from about 1 to about 75 weight percent of a macromer containing induced unsaturation, said macromer comprising the reaction product of a polyether polyol having an equivalent weight from 100 to 10,000 with a compound having both ethylenic unsaturation and a group selected from the group consisting of a hydroxyl, carboxyl, anhydride, isocyanate, and epoxy group or mixtures thereof, (b) a polyoxyalkylene polyether polyol selected from the group consisting of an ethylene oxide adduct of toluenediamine having a molecular weight range from about 300 to about 700, an ethylene oxide propylene oxide adduct of monoethanolamine having a molecular weight range from about 200 to about 500, and a polyoxyalkylene polyether polyol other than one derived from an amine, having an equivalent weight from about 100 to about 750, and mixtures thereof, (c) optionally pigment, catalyst, and inorganic filler, and (d) an organic polyisocyanate.

12. The process of claim 11 wherein the amount of induced saturation is from about 0.001 to about 1.0 mole of unsaturation per mole of polyol mixture.

13. The process of claim 1 wherein the monomer is selected from the group consisting of styrene, methylstyrene, vinyl toluene, methyl methacrylate, methacrylonitrile, divinylbenzene and acrylonitrile.

14. The process of claim 1 wherein the monomer is selected from the group consisting of styrene and acrylonitrile.

15. The process of claim 1 wherein the monomer is styrene.

16. The process of claim 1 wherein the polymerization occurs in the presence of a reaction moderator.

17. The process of claim 16 wherein the reaction moderator is selected from the group consisting of dodecanethiol, bromotrichloromethane, 2-butanol, 1-butanol, allyl alcohol, 2-mercaptoethanol and octadecyl mercaptan.

18. The process of claim 16 wherein the concentration of reaction moderator is from about 0.1 weight percent to about 10 weight percent based on the weight of the monomer.

19. A bowling ball composition comprising an outer spherical solid body of molded material enclosing a central case of heavier material wherein the outer body comprises the reaction product of (a) a graft polymer dispersion prepared by polymerizing in the presence of a free radical initiator from about 25 to about 70 weight percent based on the total weight of the dispersion, an ethylenically unsaturated monomer or mixture of monomers, in a polyol mixture comprising (1) from about 25 to about 90 weight percent of a polyol containing from 2 to 8 hydroxyl groups and having an equivalent weight from 30 to about 200, and (2) from about 1 to about 75 weight percent of a macromer containing induced unsaturation, said macromer comprising the reaction product of a polyether polyol having an equivalent weight from 100 to 10,000 with a compound having both ethylenic unsaturation and a group selected from the group consisting of a hydroxyl, carboxyl, anhydride, isocyanate, and epoxy group or mixtures thereof, (b) a polyoxyalkylene polyether polyol selected from the group consisting of an ethylene oxide adduct of toluenediamine having a molecular weight range from about 300 to about 700, an ethylene oxide propylene oxide adduct of monoethanolamine having a molecular weight range from about 200 to about 500, and a polyoxyalkylene polyether polyol other than one derived from an amine, having an equivalent weight from about 100 to about 750, and mixtures thereof, (c) optionally pigment, catalyst, and inorganic filler, and (d) an organic polyisocyanate.

20. The composition of claim 19 wherein the amount of induced saturation is from about 0.001 to about 1.0 mole of unsaturation per mole of polyol mixture.

21. The composition of claim 19 wherein the monomer is selected from the group consisting of styrene, methylstyrene, vinyl toluene, methyl methacrylate, methacrylonitrile, divinylbenzene and acrylonitrile.

22. The composition of claim 19 wherein the monomer is selected from the group consisting of styrene and acrylonitri le.

23. The composition of claim 19 wherein the monomer is styrene.

24. The composition of claim 19 wherein the polymerization occurs in the presence of a reaction moderator.

25. The composition of claim 24 wherein the reaction moderator is selected from the group consisting of dodecanethiol, bromotrichloromethane, 2-butanol, l-butanol, allyl alcohol, 2-mercaptoethanol and octadecyl mercaptan.

26. The composition of claim 24 wherein the concentration of reaction moderator is from about 0.1 weight percent to about 10 weight percent based on the weight of the monomer.