GB896396A - Improvements in or relating to synthetic resins and to processes for the manufacture thereof - Google Patents

Abstract

In a process for the manufacture of a synthetic resin at least one complex polyisocyanate (B-2) and at least one polymerizable, unsaturated monomer (B-1) which is substantially free of hydroxyl groups and is copolymerizable with the hydroxyl ester mixture are reacted with an hydroxyl ester mixture which includes at least one hydroxy-ester (A-1) of a fatty acid and of a multivalent alcohol and at least one high molecular polyester (A-2) of a fatty acid glyceride containing free hydroxyl groups and a multivalent alcohol or an amino alcohol with at least one unsaturated dicarboxylic acid, the polycondensation product containing a plurality of free hydroxyl groups. Preferably a third component (C) of the reaction mixture is employed to accelerate or inhibit the polymerization or polycondensation. These include free radical polymerization and poly addition catalysts, such as phenyl, lauryl, tertiary butyl or dibutyl peroxides, tertiary aromatic or aliphatic amines, for instance, diethyl aniline, dimethyl cyclohexylamine, pyridine and quinoline, metal soaps, for instance cobalt laurinate and lead or manganese naphthenate, and inhibitors, for instance benzo- or naphthoquinone and aldehydeamines. The (A-1) component may be castor oil or, for example, a hydroxyl-containing ester from pentaerythritol and a fatty acid. (A-2) can be synthesized by condensing a glyceride such as castor oil, a multivalent alcohol or an amino-alcohol and an unsaturated dicarboxylic acid, with which some saturated dicarboxylic acid may be mixed. The mixture of (A-1) and (A-2) is preferably pre-treated by reaction with a polyisocyanate before further reaction is effected. As component (B-1) styrene, divinylbenzene, vinylcarbazole, acrylonitrile or an ester of allyl alcohol, acrylic acid or fumaric acid are specified. (B-2) is a complex polyisocyanate obtained by reacting a polyisocyanate with a polyhydroxy compounds, such as a glycol, triol, hydroxy-ester or hydroxy-glyceride. Component B (i.e. B-1 and B-2 mixed) should also contain a content of fat, for example castor oil. It may be obtained by adding the polyisocyanate to component B-1 and a stabilizer and then reacting with the hydroxy compound. Alternatively components (A-1), A-2 and B-2 are reacted to form an unsaturated polyurethane which is cross-linked on addition of component B-1. In a further method the mixed A and B components are first reacted in the presence of an amine and copolymerization is afterwards effected at elevated temperature in the presence of an inhibitor-initiator pair, such as a benzoquinone-benzoyl or ter. butyl peroxide mixture. The resin can be processed with glass fibres, pigments, dyes, other synthetic resins, fats, hydrocarbons, ethers or esters. In the examples component A-1 is a castor oil reacted with 2% tolylene diisocyanate; A-2 is a polyester from diglycol, ethylene glycol, stearic acid mono-glyceride, phthalic anhydride and maleic anhydride, treated with 2% of tolylene diisocyanate. Mixtures of B-1 and B-2 components are products, still containing free NCO groups from the reaction of mixtures of (a) styrene, tolylene diisocyanate and hexanetriol; (b) vinyltoluene, tolylene diisocyanate and hexane-triol; (c) styrene, tolylene diisocyanate and a pentaerythritoldistearic acid ester. Mixtures of these A and B components with catalysts and inhibitors specified above for C are than prepared and used to form soft and hard cast resins, embedding resins for copper coils and a dyed coating resin.