| 摘要 |
Organopolysiloxanes which contain from 1 to 20 units of the formula <FORM:1043697/C3/1> per two units of the formula <FORM:1043697/C3/2> wherein X is a radical of the formula -CH(OR4).CH2(R3), each R1 is H or an alkyl or aryl radical, R2 is an alkylene radical which may contain oxygen, R3 is a polyether radical, R4 is R1 or an acyl radical, m is 1 or 2 and n is 1, 2 or 3, are used as heat-sensitizing agents for polymer latices, and are generally added to the latices in an amount of from 0.01 to 1.0% by weight of the solids content of the latex. The latices can also contain the usual additives. In Example (1) a heat-sensitize latex consists of (by weight): 167 pts. of 60% natural latex (i.e. 100 pts. dry natural rubber). <TABS:1043697/C3/1> <FORM:1043697/C3/3> is added to (2) a 2-chlorobutadiene-methacrylic acid copolymer latex, (4) a butylacrylate methylolether copolymer latex, (5) a butadiene-styrene copolymer latex, (6) a polyvinyl-chloride dispersion, and (7) an emulsion of a rubber-forming siloxane; a similar siloxane is added to (3) a butadiene-acrylonitrile-meth-acrylic acid copolymer latex. Other latices mentioned are those of butadiene, dimethyl-butadiene and isoprene, and copolymers thereof with styrene, a -methylstyrene, acrylonitrile and methacrylonitrile; polymers or copolymers of iso-olefines. In siloxanes A and C of the examples, the secondary -OH groups may be esterified or etherified by reaction with acetic anhydride, dimethylsulphate or benzyl chloride
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