Verfahren zur Herstellung von Hydrolyseprodukten von AEthylen/Alkenylester-Copolymeren

摘要

Copolymers of (1) ethylene, (2) at least one vinyl- and/or 1-alkyl vinyl ester of a carboxylic acid whose alpha-carbon atom is primary or saturated secondary (3) at least one vinyl- and/or 1-alkyl vinyl ester of a carboxylic acid, in which at least one of the carbon atoms bound directly to the carboxylic group is branched, and (4) optionally one or more other ethylenically unsaturated monomers, in which copolymers (2) and (3) may be identical, are partially or completely hydrolysed. Suitable components (3) are esters of pivalic acid, 1,1,3,3-tetramethylbutanecarboxylic acid, 1,2-dimethyl - 1 - isopropylpropane carboxylic acid, and 1,1,4-trimethyl pentane carboxylic acid. Suitable components (2) are esters of acetic and oleic acids. Isopropenyl acetate may be used alone, in which case (2) and (3) are identical. The hydrolysis may be effected by alkalis e.g. NaOH, KOH, LiOH, (CH3)4.N.OH, acids e.g. H2SO4, H3PO4, p-toluene sulphonic acid, HCl, while partial hydrolysis may be effected by using H2SO4 together with CH3.OH or C2H5OH. The polymer to be hydrolysed may be obtained by conventional techniques. The new polymers resulting from this process contain units of formula -[-CH2-CH2-]- and units of formula where R5 represents an alkyl group and X an hydroxyl or metal alcoholate group, optionally with units of formula where R3 is alkyl, and R4 an hydrocarbyl group whose carbon atom bound to the C=O group is primary or secondary. Other new polymers have units of formula -[-CH2-CH2-]-, units of formula and units of formula where R1, R15 are hydrogen or alkyl, X is hydroxyl or metal alcoholate group, and R2 is a hydrocarbyl group whose carbon atom bound to the C=O group is quaternary or tertiary, optionally with units of formula in which R31 is hydrogen or alkyl, and R4 is a hydrocarbyl group whose carbon bound to the C=O group is primary or secondary. Units from other monomers may be incorporated, and if such groups have an acid group it may be reacted with metal compounds to give the corresponding salts. Numerous after-treatments of the hydrolysis products are also specified. The new polymers may be compounded with pigments, plasticizers, waxes, dyes, resins and fillers, and may be vulcanized. In the examples, details of various copolymerizations in an autoclave are given, there being successive addition of ethylene and rotation of the autoclave. In examples (1), (3) and (4) vinyl pivalate/vinyl acetate/ethylene copolymers are formed; (2) vinyl pivalate/vinyl acetate/ethylene/norbornadiene are copolymerized; and (5) ethylene/isopropenyl acetate copolymers are formed. The copolymers are then hydrolysed by saponifying solutions of the copolymers in toluene with solutions of KOH in CH3.OH. Finally the copolymers are vulcanized using a standard recipe with triallyl cyanurate as vulcanizing agent and dicumyl peroxide as an activator.