GB592400A - Improvements in and relating to the manufacture of synthetic resins - Google Patents

Abstract

1-3 mols. of an unsaturated dicarboxylic acid are reacted with 1 mol. of castor oil to form an ester in which half the carboxyl group of the acid are unesterified, and the unesterified carboxyl groups are removed by heating with pyridine, quinoline, nicotine, or piperidine to yield a viscous resin which is polymerized to a solid resin with the aid of a peroxide catalyst. The decarboxylated product may be copolymerized with styrene or a higher methacrylic ester, e.g. butyl methacrylate. A mixture of the decarboxylated product with castor oil with or without butyl or another methacrylate is also useful. Suitable dicarboxylic acids are maleic, fumaric or itaconic. The compositions are suitable for casting, as filling compounds, or particularly when mixed with siccatives, as coating, impregnating or insulating compositions, with or without fillers such as wood flour, asbestos, glass fibre, sand or paper. In the examples: (1) 1.6 mols. of maleic anhydride and 0.8 mols. of castor oil were heated till the acid value dropped from 200 to 101. A little pyridine was added and heating continued at 110 DEG C. to 200 DEG C. with a further addition of pyridine. A viscous resin with acid value 36.4 was formed. Heated on a steam bath with benzoyl peroxide it set to a solid, flexible state. A solution of the viscous resin in butyl methacrylate also set to an infusible flexible gel when heated at 80 DEG C. with castor oil containing benzoyl peroxide. Examples (2) and (3) are similar, employing different proportions, Example (4) describes the copolymerization of butyl methacrylate with the de-carboxylated castor oil-maleic anhydride esterification product and benzoyl peroxide. Example (5) describes the copolymerization of styrene with a similar esterification product and tertiary butyl peroxide. Heating for 15 hours at 60 DEG C. yielded a flexible gel which became rigid on further heating at higher temperature. The Specification as open to inspection under Sect. 91 covers generally the use of any hydroxylated fatty oil, and refers generally to unsaturated polycarboxylic acids. Aconitic acid is mentioned as suitable. This subject-matter does not appear in the Specification as accepted.