GB885840A - Selective monoepoxidation of diunsaturated esters of acrylic and methacrylic acids - Google Patents

Abstract

Epoxy esters of the formula <FORM:0885840/IV (a)/1> where R1 and R2 represent hydrogen or a methyl group, R3 represents hydrogen or a C1-C11 alkyl group and R4 represents a C1-C13 alkylene group, with the proviso that R2 and R3 are such that one is alkyl and the other is hydrogen and that R3 and R4 together contain no more than 20 carbon atoms, may be polymerized or copolymerized with other compounds containing a CH2 = C< group in bulk, in solution or in emulsion at a temperature of from 0 DEG to 100 DEG C., preferably 40 DEG -80 DEG C. in the presence of freeradical catalysts, e.g. a , a 1-bis-azoisobutyronitrile, benzoyl peroxide and stearoyl peroxide, in an amount of 0,01 to 5%, preferably 0,02 to 2%, based on the weight of the polymerizable compound. Suitable copolymerizable materials are alkyl esters of acrylic and methacrylic acids, the alkyl group of which are straight or branched, of one to eight carbon atoms. Illustrative alkyl groups are methyl, ethyl, isopropyl, n-butyl, n-octyl and 2-ethylhexyl. The copolymers are useful in coating compositions, paper-treating and shrink-proofing and felt-proofing of textiles.ALSO:A mono-epoxy ester is made by selective epoxidation of the ethylenic bond in the alkenyl moiety of an ester of the formula <FORM:0885840/IV (b)/1> where R1 and R2 represent hydrogen or a methyl group, R3 represents hydrogen or a C1-C11 alkyl group, and R4 represents a C1-C13 alkylene group, with the proviso that R2 and R3 are such that one is alkyl and the other is hydrogen and that R3 and R4 together contain no more than 20 carbon atoms, which method comprises bringing together and reacting at a temperature in the range from about 30 DEG C. to about 50 DEG C., preferably 40 DEG C. to 50 DEG C., said ester and at least one mole of an epoxidizing peracid per mole of ester and reacting said ester and peracid until monoepoxidation is substantially complete, the reaction being carried out in the presence of a substantially water-soluble basic agent which when present in a 0.1 N concentration in water, imparts thereto a pH of at least 8 at 25 DEG C. The peracid is preferably added gradually, in continuous or portionwise fashion, to the unsaturated ester. Peracids specified are perbenzoic, monoperphthalic and peracetic acid in chloroform, ether and acetic acid respectively. Suitable basic agents are oxides and hydroxides of alkali metals and alkaline earth metals or salts of alkali metals and weak aliphatic carboxylic acids, e.g. sodium acetate. The starting materials are made by acidcatalyzed esterification of unsaturated alcohols with excess glacial methacrylic or acrylic acid in an inert solvent with a polymerization inhibitor, or by base-catalyzed transesterification of monoolefinic alcohols with an ester of acrylic or methacrylic acid using a polymerization inhibitor. The alcohols may also be reacted with the appropriate acid chloride or anhydride. Suitable starting materials are specified. Examples describe the preparation of crotyl methacrylate, methallyl methacrylate and 4-methyl-4-penten-1-yl methacrylate, and the epoxidation of these esters and of 10 - methyl - 10 - undecenyl methacrylate, 3-pentenyl methacrylate, methallyl acrylate, oleyl methacrylate, 8-eicosenyl methacrylate; 13,14-epoxytetracosyl-, 12,13-epoxyeicosyl-, 8,9-epoxy-dodecyl and 4,5-epoxyhexyl methacrylate 13,14-epoxytetracosyl acrylate and 9,10-epoxyoctadecyl acrylate are similarly prepared. The products are readily polymerized or copolymerized (see Group IV(a)).