| 摘要 |
A method of preparing elastomeric nonporous plastics comprises reacting an excess of an organic polyisocyanate with a first organic compound of molecular weight at least 800, and containing active hydrogen-containing groups, which groups are capable of reacting with isocyanate groups, to form a reaction product with terminal isocyanate groups, reacting this reaction product with a second organic compound having a molecular weight of less than 800, and containing active hydrogen-containing groups, which groups are capable of reacting with isocyanate groups, the quantity of the second organic compound being insufficient to react with all the isocyanate groups present, at least one of the active hydrogen-containing compounds or the polyisocyanate containing ethylenic unsaturation, the reaction between the second organic compound and the reaction product containing terminal isocyanate groups occurring in the presence of an organic peroxide. In a modification acetylenic unsaturation is present in place of or in addition to the ethylenic unsaturation. As the first organic compound there can be used polyhydric polyalkylene ethers, hydroxy-polyesters, polyhydric polythioethers, polyacetals and polyesteramides, examples of which are listed. (Polyalkylene polyethers suitable include reaction products of alkylene oxides with water or polyols). Unsaturation in the organic compound of molecular weight above 800 can be introduced by preparing it from such compounds as fumaric acid diglycol ester, allyl monoglycerine ether, or maleic, fumaric, itaconic or citraconic acids. Specified polyisocyanates are toluylene, diphenyl-methane, phenylene, naphthylene, diphenyl, azobenzene, diphenyl-sulphone, isopropylbenzene, dicyclohexyl-methane, tetramethylene and hexamethylene diisocyanates, bis-(3-isocyanatobenzoic acid)-diethylene glycol ester, and reaction products of one mol of butanediol, propene diol or pentene diol with two mols of a diisocyanate such as 2, 3-butenyl-1, 4-diisocyanate. Compounds of molecular weight less than 800 suitable are butane diol, quintol, hydroquinone or 1, 5-naphthylene di-hydroxyethyl ether, N, N-dihydroxyethyl aniline, 3, 31-dichlorobenzidine, 3, 31-dichloro-4, 41-diaminodiphenyl methane, 2, 5-dichloro-p-phenylene diamine, N-methylethanolamine, di- or tri-ethanolamine and N, N, N1, N1-tetrakis-(2-hydroxypropyl) ethylene diamine; 1, 4-butenediol, 1, 4-butynediol, fumaric acid diglycol ester, allyl monoglycerol ether and the reaction product of 2 mols hydroquinone di-hydroxyethyl ether with one mol of fumaric acid. Dicumene, di-ter. butyl, dibenzoyl, methyl ethyl ketone, diacetyl and succinyl peroxides, cumene and cyclohexanone hydroperoxides and ter. butyl perbenzoate are suitable peroxides. In examples (1) a glycol/adipic acid polyester is reacted with excess naphthylene diisocyanate. To the product at 120 DEG C. butenediol and dicumene peroxide are added. The mixture is poured into moulds and heated at 100 DEG C. for 24 hours; (3) a mixture of saturated and unsaturated polyesters is used in a similar process. The products can be used to make accumulator bladders, circular rings, gears, diaphragms, bellows, convex cups, check valve buttons, valve seats and metal reinforced rollers. |
