GB1002343A - Process for hydroxyalkylating polymers containing carboxyl groups - Google Patents

Abstract

A hydroxyalkylation process comprises reacting an ethylenic homopolymer or copolymer containing free carboxylic groups with an aliphatic or alicyclic oxide in the presence of a basic ion-exchange resin catalyst, the carboxylic groups thereby being converted to hydroxy-ester groups. The polymer may be a homopolymer of acrylic, methacrylic, crotonic, itaconic, maleic or fumaric acid or a copolymer of one or more such acids with one or more comonomers such as styrene and alkyl styrenes, alkyl acrylates and methacrylates, and amide derivatives of acrylic, methacrylic or itaconic acid. Suitable oxide reactants are ethylene oxide, propylene oxide, 1,2-butylene oxide, epichlorohydrin, glycidol and cyclohexene oxide. Suitable catalysts are styrene-divinylbenzene copolymers containing a plurality of amine functional groups or quaternary ammonium functional groups. Preferably, one equivalent of the oxide compound is used for each free carboxylic group in the polymer. The reaction is suitably effected at 80-100 DEG C. in an inert solvent such as xylene. The esterified products may be cross-linked with aminoplast or epoxy resins or with acid catalysts to form protective coatings. Examples illustrate the hydroxy alkylation of a styrene/ethyl/acrylate/acrylic acid copolymer with (a) 1,2-butylene oxide and (b) cyclohexene oxide, and methyl methacrylate/ethyl acrylate/methacrylic acid copolymer with ethylene oxide. Specifications 844,978 and 940,766 are referred to.