| 摘要 |
1,271,282. Coating. DOVERSTRAND Ltd. 16 July, 1970 [23 July, 1969], No. 37073/69. Heading B2E. [Also in Division C3] Aqueous coating compositions comprise a blend of latices of copolymers A and B, A comprising 80-99 wt% and B comprising correspondingly 1-20 wt% of total copolymer, the polymers being as follows:- A) a film-forming copolymer of (a) 45-- 70 wt% styrene and/or methyl methacrylate, (b) 0-5 wt% ethylenically unsaturated acid and (c) the remainder butadiene, said copolymer being insoluble and not swellable to any substantial extent in aqueous alkali at pH 10 at 20‹C; B) a cross-linked copolymer of (a) 35- 50 wt% butadiene and 50-65 wt% ethylenically unsaturated acid, said copolymer being substantially swellable and at least 50 wt% insoluble in aqueous alkali at pH 10 at 20‹C, the degree of cross-linking being sufficient to impart the required insolubility but not so great as to hinder swelling. The compositions may contain a pigment, e.g. china clay, TiO 2 , satin white, blanc fixe or CaCO 3 , and may be rendered more viscous by addition of alkali, particularly aqueous ammonia. The compositions may be applied to paper or to the backs of carpets or upholstery fabric, and may be added to leather finishes and to latex dispersions used for coating films of cellulose, polyester or polyolefins. |
