Patent GB-818041-A (GB)
Title: Process for the production of sheet-like structures from polymer emulsions
IPC: C08L19/00
Filed: 1956-03-05
Abstract: Coatings are produced from polymer emulsions which are made by mixing (1) an aqueous emulsion of a copolymer derived from ethylenically unsaturated monomers, 0.5 to 25 per cent by weight of which contain a keto, a carboxyl, an aldehyde or carbonamide group, the copolymer being devoid of halogen atoms and being other than a copolymer as defined in Claim 1 of Specification 761,423, [Group IV (a)], with (2) a water-soluble resin-forming formaldehyde condensation product which is used in an amount of 1 to 50 parts by weight to 100 parts by weight of copolymer, the coatings produced from these emulsions being subjected to thermal after-treatment, e.g. at between 100 DEG  and 200 DEG  C., whereby cross-linking is effected.  The coatings may be applied by brushing, spraying, dipping or casting or by means of applicator rolls or a doctor.  In an Example (2) a latex of a butadiene/styrene/acrylonitrile/methacrylic acid copolymer is mixed with a water-soluble phenolformaldehyde condensation product and the resulting emulsion is applied to a sheet of glass and stored at 145 DEG  C.ALSO:Sheet-like structures such as films, coatings, impregnations and laminated products are produced by admixing (1) an aqueous emulsion of a copolymer, other than a copolymer as defined in Claim 1 of Specification 761,423, derived from ethylenically-unsaturated monomers, 0.5 to 25 per cent by weight of which contain a keto, an aldehyde, a carboxyl or a carbonamide group, the copolymer being devoid of halogen atoms, with (2) a water-soluble resin-forming formaldehyde condensation product, such as the condensation products of formaldehyde with urea, phenol, dicyandiamide, melamine and phenyl sulphonamide, which is used in an amount of 1 to 50 parts by weight to 100 parts by weight of copolymer, and subjecting sheetlike structures produced from these emulsions to thermal after-treatment.  Monomers specified containing the above-mentioned groups are acrylic and methacrylic acids, half-esters of maleic and fumaric acids, e.g. monobutyl and monocyclohexyl maleates, acrylamide, methyl acrylamide, monobutyl acrylamide, methyl acrolein and vinyl methyl ketone; monomers copolymerizable therewith are butadiene, isoprene, dimethyl butadiene, chloroprene, styrene, vinyl and vinylidene chlorides, vinyl acetate and butyrate, acrylic and methacrylic esters, e.g. butyl acrylate, allyl acrylate and glycol diacrylate, acrylonitrile, methacrylonitrile and divinyl ether. Specific copolymers mentioned are butadiene/styrene/methacrylic acid, butadiene/acrylonitrile/styrene/methacrylic acid and styrene/butyl acrylate/methyl acrolein.  The copolymers are preferably prepared by emulsion polymerization in the presence, as catalysts, of reducing compounds of sulphur having emulsifying properties, e.g. sodium C10-C18 alkyl sulphinates, dialkylnaphthalene sulphinic acids in which the alkyl groups have at least 4 carbon atoms and C10-C18 alkylformamidine sulphinic acids.  In the examples the monomers are copolymerized in aqueous emulsion containing the sodium salt of a long-chain paraffin, the sodium salt of C12-C18 alkyl sulphinic acid and diisopropyl-xanthogen disulphide as a modifier.  The mixture of the copolymer and the formaldehyde condensation product may also contain catalysts for the final condensation of the latter, e.g. ammonia or ammonium phosphate.