GB976304A - Production of acrylates and methacrylates - Google Patents

Abstract

Esters of acrylic or methacrylic acids are prepared by a transesterification process which comprises (A) heating a mixture of (1) a primary or secondary alcohol (2) an ester of acrylic or methacrylic acid with an alcohol boiling lower than the desired ester product (3) at least one phenate of sodium, potassium, or lithium and if necessary (4) a polymerization inhibitor other than the phenate catalyst and (B) distilling an azeotrope of the ester reactant and alcohol liberated, wherein the amount of phenate present in the reaction is from 0.2 to 8 mole per cent of the alcohol reactant and the alkali metal content of the reaction mixture is no more than stoichiometric with respect to the amount of free phenol which corresponds to the phenate present. Methyl, ethyl, propyl and butyl acrylate and methacrylates may be used and unsubstituted or substituted phenate catalysts, e.g. with C1-C12 alkyl or alkoxy, amino, C1-C8 alkylamino, phenylamino, or phenyl substituents may be used and may be prepared by reaction of phenol with the alkoxide separately or in situ. Inhibitors such as hydroquinone, diphenylene diamine, and p-hydroxy diphenylamine may also be present. Suitable alcohols are C2-C18 alkanols; alkoxy-alkanols; alkenyloxy-alkanols; alkenols; phenoxyalkanols; phenoxyalkoxyalkanols or phenoxypolyalkoxy alkanols; phenoxyalkoxyalkanols and phenoxypolyalkoxyalkanols with alkyl substituents; cycloalkanols; phenylalkanols; alkynols; dialkylaminoalkanols; t-alkylaminoalkanols; glycols and glycerols and other polyhydric alcohols and examples are listed. Examples describe the preparation of 1,3-butanediol dimethacrylate, methylcyclohexyl acrylate, phenylethyl and octadecyl methacrylates the dimethacrylate of triethylene glycol, glycerol trimethacrylate, 2-ethylhexyl, benzyl, and octylphenoxyethyl acrylates, 2-vinoxyethyl and methoxybutyl methacrylates, octenyl acrylate, phenoxyethyl methacrylate, 2,2-dimethyl-3-dimethylaminopropyl, 2-dimethylaminoethyl and 2-dimethylamino-2-methylpropyl methacrylates, cyclohexyl methacrylate, octylphenoxypolyethoxyethyl acrylate, and t-octylaminoethyl methacrylate.