| 摘要 |
A process for the manufacture of plastics which have a high resistance to saponification and chemicals comprises reacting a polyisocyanate with a polythioether produced by condensing glycols which contain thioether groups and are hydroxyalkylated once or several times with one another or together with non- hydroxyalkylated glycols containing thioether groups, or by condensing non-hydroxy-alkylated glycols containing thioether groups with glycols which are hydroxyalkylated once or twice, the glycol component thereof having at least three carbon atoms before hydroxyalkylation. The preparation of the condensation products is the subject of Specification 819,384. They may be employed in admixture with polyesters or further polyethers. Aliphatic cycloaliphatic and aromatic di- and tri-isocyanates are specified. The polythioethers can be reacted with excess diisocyanate to give a product which is cross-linked with glycols, diamines or water, or the product with free isocyanate groups can be reacted with a diamine, glycol and/or aminoalcohol to give a storable intermediate having free amino or hydroxyl groups which can be cured with further diisocyanate. In making foamed materials the polythioether is reacted in one or two stages with polyisocyanates and water in the presence preferably of tertiary amines, advantageously those of the formula HO-R-NR1-R-OH in which R is an alkylene group and R1 is a hydrocarbon or hydroxyethyl group. Salts of fatty acids, sodium phenolate and iron acetonylacetate can also be added. The products can be used as coatings, foils or adhesives by preparing a solution of the polythioether and a polyisocyanate (which may be masked). Moulding compositions can be prepared by mixing the reactants together with a filler, such as sawdust, chalk, carbon black, iron oxide or colloidal silica, and moulding under heat and pressure. In examples (1) a glycol HO(CH2)2S(CH2)2S(CH2)2 S(CH2)2OH is condensed with butane dihydroxyethyl glycol. The polythioether obtained is reacted with toluylene diisocvanate and Nmethyl diethanolamine, the material obtained (of OH number 50.5) being converted to a foam by adding a mixture of water, the adipic acid ester of N-diethyl ethanolamine, diethylammonium oleate and castor oil sulphate followed by toluene 2,4- and 2,6-diisocyanates; (2) monohydroxyethyl thiodiglycol (HO(CH2)2-O(CH2)2S(CH2)2OH is condensed to give a polythioether, which is reacted with excess 1,5-naphthylene diisocyanate and the product is reacted with 1,4-butylene glycol and cured by heating. Specifications 791,854, and 818,359 also are referred to.ALSO:A process for the manufacture of plastics which have a high resistance to saponification and chemicals comprises reacting a polyisocyanate with a polythioether produced by condensing glycols which contain thioether groups and are hydroxy-alkylated once or several times with one another or together with non-hydroxyalkylated glycols containing thioether groups, or by condensing non-hydroxyalkylated glycols containing thioether groups with glycols which are hydroxyalkylated once or twice, the glycol component thereof having at least three carbon atoms before hydroxy alkylation. The preparation of the condensation products is the subject of Specification 819,384. They may be employed in admixture with polyesters or further polyethers. In making foamed materials the polythioether is reacted in one or two stages with polyisocyanates and water, preferably in the presence of tertiary amines, advantageously those of the formula HO-R-NR1-R-OH in which R is an alkylene group and R1 is a hydrocarbon or hydroxyethyl group. In example (1) a glycol HO(CH2)2 S(CH2)2. S(CH2)2. S(CH2)2 OH is condensed with butane dihydroxyethyl glycol. The resulting polythioether is reacted with toluene diisocyanate and N-methyl-diethanolamine, the material obtained (of OH number 50,5) being converted to a foam by adding a mixture of water, the adipic acid ester of N-diethyl ethanolamine, diethylammonium oleate and castor oil sulphate, followed by toluene 2, 4 and 2, 6- diisocyanates. Specifications 791,854 and 818,359 also are referred to. |
