Verfahren zur Herstellung von mit Schwefel vulkanisierbaren Polyurethanelastomeren

摘要

1,183,366. Polyurethane elastomers. MICHELIN & CIE (Compagnie Generale des Etabs Michelin). 20 April, 1967 [21 April, 1966], No. 18323/67. Heading C3R. Polyurethane elastomers of M.W. 20,000 to 200,000 and one or more ethylenic unsaturations at each end of the molecular chain and ethylenic unsaturations at intervals along the molecule either in the molecular chain itself or in branches from the molecular chain such that the mean interval between adjacent unsaturations is 1000 to 8000 units of molecular weight are prepared by reacting (a) n moles of a dihydroxylated polymer of M.W. 800 to 6000; (b) 2 moles of a compound which is monofunctional relative to diisocyanates and which contains at least one ethylenic double bond; (c) m moles of a low M.W. ethylenically unsaturated compound which is bifunctional with respect to diisocyanates and which is of the type R-CH=CH-R1, wherein either R represents a hydrogen atom or an aliphatic or aromatic radical and R1 represents an organic radical having two functions reactive with regard to isocyanates, or R and R1 represent two.radicals each having a function which is reactive with regard to diisocyanates, in either case the interval between double bonds and the or each reactive function containing at least one C, O or S atom; and (d) m + n + 1 moles of a diisocyanate, m and n being chosen to satisfy the M.W. conditions. The polymer (a) may be a conventional dihydroxylated polyester, polyether, polyesteramide or polyetherester. Suitable monofunctional unsaturated compounds (b) are dialloxy propanol, allylpropenyl-carbinol, allylvinylcarbinol, diallyl - carbinol, alpha - diallylamine, allylamino - 4 - phenyl - 4 - but - 1- ene, allyl - alcohol, allylamine and allyloxypropanol. The unsaturated compounds (c) may be allyloxypropanediol, a monoallyl ether of trimethylolpropane, an allyl diether of pentaerythritol, N - allyldiethanolamine, allyl - dipropane - 1,3 - diol, 1,1 - dimethanolcyclohex - 3 - ene, 1,1 - dimethanol - 4 - methyl - cyclohex - 3 - ene, hexa - 1,5 - diene - 3,4 - diol, pent - 1 - ene - 4,5 - diol, octa - 2,6 - diene - 4,5 - diol and allyl thioethers of diols. Conventional diisocyanates may be used. Saturated compounds which are bifunctional relative to diisocyanates may also be included in the reaction mixture to form allophanate or biuret structures. The polyurethanes containing unsaturated groups may be vulcanized using a sytem comprising sulphur, mercaptobenzothiazole, mercaptobenzothiazole di- or poly-sulphide and an activator which is a complex of zinc or cadmium halides with mercaptobenzthiazole di- or poly-sulphide, mercaptobenzothiazolmorpholinosulphenamide, triethylene diamine or tri (1,3,5-mercaptobenzothiazoletriazine).