Patent ID: 6242555
Filing Date: 2001-06-05
Classification: C08G

Abstract:
A process for the production of micro-cellular or non-cellular, light stable elastomeric, flexible or semi-flexible polyurethane mouldings having a density of at least 900 kg/m.sup.3 and a flexural modulus according to ASTM D790 of between 5 and 300 Mpa, from a reaction mixture by a reaction injection moulding process, whereinA) an isocyanate component comprising an isophorone diisocyanate (IPDI) timer/monomer mixture having an NCO content of from 24.5 to 34% by weight, is reacted withB) isocyanate-reactive components comprising:b1) a polyol component comprising a polyetherpolyol having terminal OH groups, an average nominal functionality of from 2 to 4, and an average equivalent weight of from 800 to 4000;b2) from about 3 to about 20% by weight, based on the weight of components b1, b2 and 3, of at least one chain extender component having as functional groups only aliphatic or alicyclic OH groups, a functionality of 2, equivalent weight of up to 80, and a primary OH content of at least 50%;b3) from about 2 to about 10% by weigh, based on the weight of components b1, b2 and b3, of at least one amine-initiator component forming a co-catalytic system with catalyst component C and having from 2 to 3 functional aliphatic NH, NH.sub.2 or OH groups, at least one of which is a secondary or primary amino group, and an equivalent weight of up to 150, component b3 including at least 1% by weight of diethanolamine (DEOA), based on the weight of components b1, b2 and b3;in the presence ofC) at least one catalyst component selected from the group consisting of organolead (II), organobismuth (III), and organotin (IV) catalysts, the maximum amount of each of these catalysts being respectively for the organolead catalyst 1.5% by weight, the organobismuth catalyst 1.5% by weight and for the organotin catalyst 3% by weight, based on the weight of components b1, b2 and b3, the organotin catalyst being used either in combination with the organolead and/or the organobismuth catalyst, and/or in combination with a diazobicyclo-alkene catalyst and/or a salt of this latter catalyst with a weak acid;D) at least one pigment component, andE) at least one antioxidant/UV absorber component;wherein said components are processed via a two-component solvent-free polyurethane reaction injection moulding process at an isocyanate index of 90 to 120, in a closed mould preheated to a temperature of 80 to 130.degree. C., wherein the reaction mixture is injected at a temperature of between 30 and 80.degree. C., the polyurethane reaction mixture, being composed to enable a demoulding time of less than 60 seconds, is substantially free of physical blowing agents and containing up to 0.15% by weight, based on the total weight of the reaction mixture, of water.