Patent GB-496892-A (GB)
Title: Manufacture of acryloxy carboxylic acids and their esters
IPC: C08F20/62
Filed: 1937-06-07
Abstract: Acryloxycarboxylic acids and their esters, of the general formula CH2 : CR.COOR1COOR2, where R is hydrogen or a monovalent hydrocarbon radicle, R1 is a divalent hydrocarbon radicle and R2 is hydrogen or a monovalent hydrocarbon radicle, are manufactured by reacting an ester of a monomeric halogenated aliphatic carboxylic acid, or an aromatic or hydroaromatic ester having a halogenated aliphatic side chain, with an alkali metal salt of an acid of the acrylic series, or by reacting a monomeric or polymeric hydroxycarboxylic acid, or an ester thereof, with an anhydride or acid chloride of an acid of the acrylic series, the reaction being carried out in the presence or absence of a polymerization inhibitor.  Suitable starting materials are, on the one hand salicylic, hexahydrosalicylic, p-hydroxybenzoic, hydroxynaphthoic, and partially hydrogenated hydroxynaphthoic acids, their esters with monohydric or polyhydric alcohols, e.g. methyl, ethyl, propyl, butyl, octyl, dodecyl, c tyl, 9 : 10-octadecenyl, octadecyl, allyl, cyclohexyl or benzyl alcohols, ethylene, propylene or other polymethylene glycols, glycerol, sorbitol and homologues thereof, also esters of glycollic, b -hydroxypropionic, a -, b - and g -hydroxybutyric, tartronic, malic, citric, glyceric and tartaric acids and corresponding acids having halogen atoms in place of the hydroxyl groups, also esters of mandelic, tropic and o-hydroxymethylbenzoic acids and of the corresponding acids having a halogen atom in place of one or more of the hydroxyl groups in the side chain, also polymeric (e.g. polyvinyl) esters of hydroxyaliphatic carboxylic acids, and on the other hand the salts, anhydrides and chlorides of acrylic acid, a -alkyl (e.g. methyl, ethyl, propyl or higher alkyl), a -aryl (e.g. phenyl or naphthyl) or a -aralkyl (e.g. benzyl) derivatives thereof, and also salts of polymeric acids of the acrylic series.  The products may be polymerized, by means of heat or light in the presence or absence of a polymerization catalyst, if desired in admixture with other polymerizable compounds, e.g. vinyl chloracetate, acetate or chloride, alkyl (e.g. methyl or ethyl) vinyl ketones, styrene, acrylic and methacrylic acids and their esters such as methyl acrylate, methyl or ethyl methacrylate, acrylic and methacrylic amides and nitriles, butadiene, isoprene, chlorobutadiene, itaconic and fumaric acids and their esters, amides and nitriles. The products, in monomeric or partially or completely polymerized form, may be used as coating compositions, alone or modified with natural or synthetic resins, especially other methacrylate-type resins, or with cellulose derivatives, oils, waxes, plasticizers, pigments or fillers, also in moulding compositions, as safety glass adhesive or other interlayer compositions, as adhesives in general, for sizing, coating or impregnating fabrics, cloth, paper or regenerated cellulose sheet material, or as rubber substitutes, polymerization being effected in situ where necessary.  In examples: (1) methyl chloracetate is heated with potassium methacrylate in methanol solution in the presence of hydroquinone to produce methyl methacryloxyacetate; the product is polymerized by heating with benzoyl peroxide; (2) methyl a -bromobutyrate similarly yields methyl a -methacryloxybutyrate, which is interpolymerized with methyl methacrylate by heating with benzoyl peroxide; (3) ethyl bromomalonate is heated with potassium methacrylate in absolute alcoholic solution in the presence of hydroquinone, producing ethyl methacryloxymalonate; the product is polymerized, or interpolymerized with methyl acrylate, by heating with benzoyl peroxide; (4) glycol dilactate is heated with methacrylic anhydride in toluene solution in the presence of potassium methacrylate to yield glycol a -methacryloxypropionate; the product may be polymerized; (5) castor oil is heated with methacrylyl chloride, benzene and calcium carbonate to produce glyceryl methacrylricinoleate; the product may be polymerized by heating with benzoyl peroxide; (6) potassium acrylate is used in place of the methacrylate in (2), yielding methyl acryloxybutyrate.  Samples have been furnished under Sect. 2 (5) of: (a) ethyl a -phenylacryloxyacetate, prepared by neutralizing atropic acid with alcoholic caustic potash and refluxing the solution with ethyl chloracetate; (b) methyl o-methacryloxybenzoate, prepared by refluxing methyl salicylate with methacrylyl chloride; (c) methacryloxyacetic acid, prepared by refluxing a mixture of glycollic acid, methacrylyl chloride and benzene.  The Specification as open to inspection under Sect. 91 comprises also the reaction of various proportions of salts of monomeric acids of the acrylic series with polymers of halogenated aliphatic carboxylic esters other than vinyl chloracetate, and the reaction of alkali metal salts, chlorides or anhydrides of acids of the acrylic series with interpolymers of vinyl esters of halogen- or hydroxyaliphatic carboxylic acids, e.g. vinyl chloracetate or glycollate, with other polymerizable substances, e.g. ethyl acrylate, butadiene or vinyl chloride.  This subject-matter does not appear in the Specification as accepted.