Patent GB-1113602-A (GB)
Title: Elastomeric materials and process therefor
IPC: D01F6/38
Filed: 1965-05-25
Abstract: An elastomeric composition comprises (A) from 50 to 90% by weight of a cross-linked base elastomer containing at least 75% by weight of units of one or more (C2-C8)-alkyl acrylates or a mixture thereof with at most an equimolar amount of ethylene, propylene and/or isobutylene and (B) from 50 to 10% of reinforcing polymer dispersed throughout the base elastomer, the reinforcing polymer containing (1) units of one or more of the following monomers: vinylidene chloride, fluoride or fluorochloride and vinyl chloride or fluoride, and, if required to reduce the crystallinity of the reinforcing polymer, (2) up to 12% by weight of one or more other alpha, beta-monoethylenically unsaturated monomers.  The composition may be prepared by physical admixture of separate dispersions of polymers (A) and (B) or, preferably, by a sequential polymerization in which the monomer charge of polymer (B) is emulsion polymerized in an aqueous dispersion of elastomer (A).  0.5 to 25% of a monomer effective to cross-link elastomer (A) may be contained in said elastomer, e.g. monomers containing hydroxyl, amide, ureido, imide, carboxylic or epoxy groups or polyunsaturated monomers. Additional monomers may be included to increase the glass transition temperature of the elastomer, preferably acrylonitrile. In the examples, sequential emulsion polymerization processes employing redox catalysts are used to produce compositions in which elastomer (A) and reinforcing polymer (B), respectively, are as follows:  (1) ethyl acrylate/acrylamide/N-methylol acrylamide copolymer and vinylidene chloride/methyl methacrylate copolymer, (2) n-butylacrylate/acrylonitrile/acrylamide /N-methylolmethacrylamide copolymer and vinylidene chloride/ethyl acrylate copolymer, (3) 2-ethylhexylacrylate /acrylic acid / vinylidene chloride/glycidyl methacrylate copolymer and vinylidene chloride methyl methacrylate copolymer, (4) n-butyl acrylate/methacrylic acid / 4 - pentenamide/N-methyl-4-pentenamide copolymer and vinylidene chloride/acrylic acid/n-butyl acrylate copolymer, (5) n-butyl acrylate/methyl methacrylate/acrylamide/N-methylol-acrylamide copolymer and vinylidene chloride/ethyl acrylate copolymer, (6) n-butyl acrylate/acrylonitrile /methacrylamide/N-methylolmethacrylamide copolymer and vinylidene chloride/n-butyl acrylate copolymer, (7) n-butyl acrylate/acrylonitrile /methacrylamide copolymer and vinylidene chloride/ethyl acrylate copolymer, (11) and (15) as (6) except that acrylic acid is also included in polymer (B), (12) n-butyl acrylate/vinylidene chloride/methacrylamide/acrylic acid/N-methylol methacrylamide copolymer and copolymer (B) as in (11) and (13) n - butyl acrylate / acrylonitrile / methacrylamide /N- methylolmethacrylamide copolymer and copolymer (B) as in (11). In other examples, polymers (A) and (B) are produced separately and mechanically mixed, the polymers being as follows: (16) n-butyl acrylate/acrylonitrile /methacrylamide / N - methylol methacrylamide copolymer and vinylidene chloride / n - butyl acrylate / acrylic acid copolymer, (17) and (18) elastomer as in (16) plus vinyl chloride/diethyl maleate copolymer or polyvinyl chloride, (19) to (21) elastomer as in (16) plus a vinylidene chloride/ethyl acrylate copolymer.  The fibres produced from the compositions prepared are cured by heating, the composition produced in Example 7 being treated with formaldehyde prior to being spun. The latices produced in Examples 3 and 6 are sprayed on to substrates (see Division B2).ALSO:Wood, metal, paper, leather, textiles are coated, and in Example 3, a cotton pile fabric is sprayed with a latex of a graft polymer produced by grafting vinylidene chloride and methyl methacrylate on to a copolymer of 2-ethylhexyl acrylate, acrylic acid, vinylidene chloride and glycidyl methacrylate to provide on the fabric an elastic backing, which is cured by heating.  In Example 6, a latex of a graft polymer of vinylidene chloride and n-butyl acrylate on a copolymer of n-butyl acrylate, acrylonitrile, methacrylamide and N-methylolmethacrylamide is sprayed on to steel panels and the coating is cured.