| 摘要 |
<p>Compositions comprising wax-free aqueous dispersions of solid particles of (1) copolymers of at least 75% of vinylidene chloride with at least one ethylenically unsaturated monomer, said particles having a size within the range 0.05 to 0.5 micron; and (2) polyvinyl chloride having a size within the range 0.10 to 1.5 microns, the amount of polyvinyl chloride particles being within the range 0.1 to 5% of the total weight of polymer particles in the dispersion, may be used to coat non-fibrous organic sheet material. Specified copolymer are those of vinylidene chloride with butadiene, chloroprene, vinyl acetate, methyl vinyl ketone, styrene, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutylmethacrylate, methoxymethoxyethyl methacrylate, vinyl chloride and dichlorovinylidene fluoride, terpolymers of the above with itaconic acid and copolymers of vinylidene chloride with dimethyl itaconate, diethyl itaconate, dibutyl itaconate, vinyl pyridine and isoprene. Specified sheet materials are of regenerated cellulose, polyvinyl alcohol, polyvinyl acetals, vinyl chloride-vinyl acetate copolymers, polyethylene, polyethylene, terephthalate, polyhexamethylene adipamide, polyhexamethylene sebacamide, polycaproamide, cellulose acetate, cellulose nitrate, cellulose acetate-butyrate and casein. Example I describes the copolymerization in aqueous dispersion of vinylidene chloride, methyl acrylate and itaconic acid in the presence of ammonium persulphate, sodium metabisulphite and the sodium salts of sulphated C10-C18 straight chain alcohols. Specifications 386,775, 461,236, 472,264, 495,349, 523,720, 651,769, 654,342 and U.S.A. Specifications 2,071,250, 2,147,180 and 2,251,752 are referred to.</p> |
