Patent GB-581473-A (GB)
Title: Improvements relating to synthetic resins
IPC: C08F222/16
Filed: 1944-07-21
Abstract: Isopropenyl acetate is copolymerized with one or more esters of maleic or fumaric acids.  The maleic or fumaric esters are represented by the formula ROOC-CH=CH-COOR1, where R is alkyl, substituted alkyl, or an unsaturated or cyclic hydrocarbon group and R1 is alkyl, substituted alkyl, an unsaturated or cyclic hydrocarbon group or a hydrogen atom.  Specified as R or R1 are methyl, ethyl, n-propyl, iso-propyl, benzyl and sec-butyl.  Specified esters are di-(p-chloroethyl), di-(b -ethoxyethyl), di-(b -cyanoethyl), diallyl, dicyclohexyl, diethyl and diisopropyl fumarates and dimethyl maleate. More than one ester can be used simultaneously in the copolymerization while another unsaturated compound, e.g. vinyl acetate, styrene, methyl a -methacrylate or methyl isopropenyl ketone may also be present. Copolymerization is preferably carried out by heating with a catalyst such as benzoyl acetyl, lauryl or hydrogen peroxide, a perborate or a persulphate (such as an alkali metal perborate or persulphate).  A solvent or diluent may be present and the copolymerization may take place in aqueous or other emulsion. The resin may be modified by incorporation of a plasticiser, e.g. benzyl phthalate or succinate, butoxyethyl tetrahydrofuroate, cyclohexyl acetate, diethylene glycol monobutyl ether, diethylene glycol dibutyrate, ethoxyethyl adipate or sebacate, ethylene glycol monobenzyl ether, methoxyethyl phthalate, tetrahydrofurfuryl adipate, triacetin, tripropionin, triamyl, tributyl or triphenyl phosphate, triethyleneglycoldiacetate, camphor and tribromophenol, or of other agents, e.g. non-drying oils, drying oils, semi-drying oils, natural resins, other synthetic resins, waxes, cellulose acetate and other cellulose derivatives, pigments, fillers or dyes.  The products are suitable for moulding by compression or injection and they may be extruded as wires, fibres or threads, they can also be used as laminated material for safety glass.  After incomplete copolymerization the syrupy mass is useful as an impregnating agent for porous substances such as paper and textiles or as a cement for glass surfaces of lenses.  In examples, isopropenyl acetate is copolymerized with (1) dimethyl maleate; (2) diethyl maleate; (3) di-n-propyl maleate; (4) di-n-butyl maleate; (5) di-(b -chloroallyl) maleate; (6) dimethyl fumarate; (7), (8), (9), (10), (12), (13) and (21) diethyl fumarate; (11) diisopropyl fumarate; (14) diethyl fumarate and dimethyl fumarate; (15) di-n-butyl fumarate; (16) di-n-benzyl fumarate; (17) di-(b -chloroethyl) fumarate; (18) dibenzyl fumarate; (19) di-(b -cyanoethyl) fumarate; (20) monomethyl fumarate; (22) ethyl-n-butyl fumarate; (23) dicyclohexyl fumarate; (24) di-(b -ethoxyethyl) fumarate; (25) di-(2-ethylhexyl) fumarate; (26) di-(b -chloroally) fumarate; and (27) di-(b -cyanoethyl) fumarate.  The isopropenyl acetate is prepared by the action of ketene on acetone.  Examples show the preparation of di-(b -chloroalkyl), ethyl butyl, dicyclohexyl, dihexyl, b -ethoxy ethyl, di-n-butyl, and di-(2-ethylhexyl) fumarates from maleic anhydride and the corresponding alcohols by heating with p-toluene sulphonic acid, while di-(b -cyanoethyl) fumarate is prepared from maleic anhydride and b -hydroxy-propionitrile by heating with p-toluene sulphonic acid.