| 摘要 |
<p>An aqueous copolymer emulsion, for dressing leather, comprises a copolymer of (a) 25-60% of a conjugated aliphatic diene of 4 to 6 carbon atoms, (b) 2 to 20% of acrylamide and/or an alpha-substitution product thereof and (c) 73-20% of at least one other copolymerizable monoethylenically unsaturated monomer. Specified dienes are butadene, isoprene, 2-3-dimethylbutadiene, 2-chlorobutadiene, 2-3-dichlorobutadiene, and 2-cyanobutadiene while, meth-, alpha-ethyl, alpha-dodecyl, alpha-chloro and alpha-carboxy-, acrylamides and acrylonitrile, alpha-chloroacrylonitrile, styrene, alpha-methylstyrene, acrylic acid, methacrylic acid, alphaalyloroacrylic acid, an alkyl ester of acrylic acid, an alpha-alkylacrylic acid, an N-alkyl or N,N-dialkylamide of acrylic or of an alphaalkyl-acrylic acid, an ester or semi-ester of maleic or fumaric acid, a vinyl ester of a carboxylic acid, an unsaturated halogenated hydrocarbon, vinylpyridine and isobutylene are specified other components. The polymerization may take place in aqueous emulsion by the addition of a free-radical forming substance or of a redox system, in the presence of anionic, cationic or non-ionic emulsifiers and protective colloids. Regulators such as alkyl mercaptans may be added during polymerization. Stabilizers, e.g. the condensation products of cresols with camphene, 2-6-di-t-butyl-p-cresol, aralkylation products of diphenylamine, and 2 2,21-methylene-bis-(4-methyl-6-cyclohexylphenol and the additives customary for dressing leather may be added to the aqueous copolymer emulsion. Specifications 678,614 and 777,293 are referred to</p> |
