DE1694790

1,152,125. Unsaturated polyesters. PPG INDUSTRIES Inc. 17 May, 1967 [30 June, 1966], No. 22805/67. Headings C3P and C3R. An unsaturated polyester is made by reacting (a) an ethylenically unsaturated dicarboxylic acid (e.g. maleic, fumaric acid, itaconic or citraconic acid), (b) a neopentyl-type glycol of formula where R 1 and R 2 are hydrogen atoms or lower alkyl radicals and R 3 and R 4 are lower alkyl radicals, and (c) a cycloaliphatic glycol of formula where R is a cyclohexane ring which may be alkyl substituted, R is an alkylidene radical and n is 0 or 1. Up to 60 mol per cent of the unsaturated dicarboxylic acid may be replaced by a saturated dicarboxylic acid (e.g. sebacic, adipic, suberic, phthalic, isophthalic or terephthalic acid). Up to 30 mol per cent of the glycol component (b) + (c) may be replaced by a different glycol (e.g. ethylene-, propylene- or 1: 4-butylene glycol). Up to 15 mol per cent of the dicarboxylic acid may be replaced by a higher polycarboxylic acid (e.g. hemimellitic or trimellitic acids). Examples describe the manufacture of polyesters by reacting (a) maleic anhydride, (b) 4,41-isopropylidene dicyclohexanol, (c) neopentyl glycol and (d) phthalic anhydride or isophthalic acid. Ingredient (a) may be added after reaction of the other three. The unsaturated polyesters may be mixed with unsaturated monomers (e.g. styrene, vinyl toluene, divinyl benzene, methyl acrylate, methyl methacrylate, acrylonitrile or diallyl phthalate) to form polymerizable compositions. Such compositions may also contain (i) inhibitors (e.g. phenylic compounds, quinonic compounds, quaternary ammonium salts or tertiary amine hydrochlorides); (ii) polymerization catalysts (e.g. benzoyl peroxide, tent.-butyl perbenzoate, tert.-butyl hydroperoxide, cumene hydroperoxide or azo-bis (isobutyronitrile)); or (iii) accelerators (e.g. cobalt salts or tertiary amines). Uses.-Coating and linings.