| 摘要 |
1,178,304. Heat-sensitive latices; polyethersiloxane reaction product. FARBENFABRIKEN BAYER A.G. 25 Jan.. 1967 [9 March, 1966], No. 3724/67. Headings C3P, C3R and C3T. A mixture of 50-85 parts by weight of butadiene, 14-49 parts by weight of acrylonitrile and/or styrene, and 1-8 parts by weight of methacrylic acid is polymerized in aqueous emulsion in the presence of an emulsifier comprising, per 100 parts by weight of monomer: (a) 2-8 parts by weight of a C 12-18 alkali sulphate or sulphonate; (b) 0-4 parts by weight of a non-ionic emulsifier with a turbidity point above 75‹ C. ; and (c) 0-4 parts by weight of a non-ionic emulsifier with a turbidity point below 75‹ C., the quantities (b) and (c) being not below 0-5 parts by weight. The emulsion produced can then be heat-sensitized by polyoxyalkylene siloxanes. Suitable emulsifiers (b) are oxyethylated stearyl and oleyl alcohols with 15 or more ethylene oxide units and oxyethylated nonylphenol with 12 or more ethylene oxide units. Emulsifiers (c) include oxyethylated benzyl phenol with 12-20 ethylene oxide units and oxyethylated nonyl phenol with 8-10 ethylene oxide units. The reaction product of an oil of composition with a slight excess of a copolymer of equal parts of ethylene oxide and propylene oxide in the presence of boron trifluoride is used as the heat-sensitizing agent for the latex.
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