| 摘要 |
Halogen-containing polymers, e.g. chlorinated rubbers, are stabilized by addition of a pyrazole of the general formula:- <FORM:0866936/IV (a)/1> wherein R, R1 and R11 are hydrogen, halogen, cycloalkyl, aralkyl, alkyl (e.g. containing 1-18 C atoms), or aryl radicals, not containing ethylenic unsaturation; the aryl radical may be substituted by, for example, Cl, Br, OH, alkyl or alkoxy. The Specification lists a number of pyrazoles; in Examples, 3 : 5-diphenyl-, 3-phenyl-, 3-methyl-5-phenyl-; 3-phenyl-5-chlorophenyl- and 3-phenyl-5-p-methoxyphenylpyrazole are used. The polymers specified are those of vinyl and/or vinylidene chloride, chlorobutadienes, chlorostyrenes and copolymers thereof with, e.g., vinyl acetate propionate or benzoate, methyl, ethyl, butyl and allyl acrylates and methacrylates, maleic and fumaric acids, styrene, divinylbenzene and alpha-methylstyrene, butadiene and isoprene, acrylonitrile and anides and anilides of acrylic and methacrylic acids, and halogenated resins such as chlorinated natural and synthetic rubbers, chlorinated polyvinyl chloride and chlorinated polystyrene; however a vinylchloride polymer and particularly polyvinylchloride itself is preferred. The following plasticizers, the use of which is optional, are mentioned:-aliphatic and aromatic esters of, e.g. phthalic, adipic, azelaic and sebacic acids, and wholly or partially aromatic esters of phosphoric acid; many such plasticizers are specified. |
