| 摘要 |
1357461 Fibrous vinylacetate polymer compositions PLASTI-FIBER FORMULATIONS Inc 14 April 1972 [16 April 1971] 17258/72 Heading C3P A roofing composition comprises an aqueous dispersion of (a) a vinyl acetate homopolymer, a copolymer of vinyl acetate and an acrylic acid ester of a C 1-8 alkanol, or a mixture of two or more thereof, (b) a fibrous filler derived from bagasse (extracted sugar cane) which contains an alum, and (c) a finely divided pigment. Component (b) is a new product, the preparation of which is described in Specification 1,357,462. Acrylic acid esters specified are ethylacrylate, butyl acrylate, a mixture of these two, and a mixture of 2-ethyl hexyl acrylate and butyl acrylate. The fibres normally contain 0À1 to 0À4 weight per cent (based on the fibres) of the alum. A free alum may also be present in an amount between 0À5 and 1À5% by weight of total solids. The composition as a whole preferably contains (based on total solids weight) 55-65% of (a), 5-15% of (b) and 15-35% of (c). In the examples, commercially available vinyl acetate homo- or copolymer latexes are used, with pigments selected from one or more of rutile TiO 2 , clay and whiting. Other conventional additives such as mercurial fungicides, cellulosic thickeners and antifoaming agents, are also used. |
