| 摘要 |
A latex composition comprises a stable aqueous dispersion of water-insoluble copolymerized monomers comprising from 1 to 10% of the total monomer weight of an a ,b -ethylenically unsaturated carboxylic acid and at least one ethylenically unsaturated ester of the cyclohexyl esters and the C1 to C18 alkyl esters of acrylic acid or methacrylic acid, any balance of monomer being a monovinylidene monomer having the formula <FORM:1012251/C3/1> wherein R is hydrogen or methyl and Q is the radical -CN or an aromatic hydrocarbon having from 6 to 12 carbon atoms, in an aqueous system containing from 0.004 to 0.1 weight per cent, based on monomer weight, of predominantly anionic water-soluble emulsifier. Many monomers are listed, those exemplified areacids-acrylic acid and methacrylic acid; esters-ethylacrylate, butylacrylate, and methyl methacrylate; other monomers-styrene and acrylonitrile. The anionic emulsifier may be an alkyl aryl sulphonate, an alkali metal alkyl sulphate, a sulphonated alkyl ester, or a fatty acid soap. Those exemplified are dioctyl sodium sulphosuccinate and disodium dodecyldiphenyl ether disulphonate. The usual peroxide or peracid free radical catalysts may be used to copolymerize the monomers, optionally activated with reducing agents to form redox systems. The catalyst exemplified is sodium persulphate. After polymerization the latex may be rendered mildly alkaline, preferably by the addition of ammonia. The usual additives may be included in the composition.
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