Patent GB-998188-A (GB)
Title: Copolymers
Inventor: KINE BENJAMIN BERRYL
IPC: D04H1/64
Filed: 1960-07-26
Abstract: Water-insoluble addition copolymers are made which contain (A) recurring N-methylolamide units of the formula <FORM:0998188/C3/1> and (B) units which contain a group reactive with N-methylolamide groups, the total amount of (A) and (B) being not more than 4.5% by weight of the copolymer, and the balance of the copolymer being constituted by compatible units.  Units (A) are derived from N-methylol acrylamide or methacrylamide or, in a modification, from N-methylolmaleimide.  Units (B) are derived from monomers containing carboxyl, hydroxyl, amide or amine groups.  The compatible units may be derived from unsaturated esters, nitriles, aryl hydrocarbons, and halides. The copolymers are preferably made by copolymerization of the monomers in aqueous emulsion containing ammonium persulphate, sodium hydrosulphite, and an ethylene oxide-t-octylphenol condensate. The resulting dispersions are used in coating and impregnating various substrates, for which purpose there may be added thereto pigments, aminoplast condensates, thickening agents, polyepoxides, and dispersions of other addition polymers.  After application, the copolymer compositions are thermoset by heating at 240-750 DEG  F. The Examples describe the aqueous emulsion polymerization of (1) vinyl toluene, ethyl acrylate, methacrylamide and methylol methacrylamide, (4) ethyl acrylate, acrylamide and methylol acrylamide, (6) methyl methacrylate, methyl acrylate, methacrylic acid, acrylamide and N-methylolacrylamide, (7) ethyl acrylate, acrylonitrile, acrylamide, methacrylic acid and methylol acrylamide, (8) n-butyl acrylate, styrene, acrylamide and methylol methacrylamide, (9) ethyl and 2-ethyl hexyl acrylates, vinylidene chloride methacrylamide and methylol methacrylamide, (10) ethyl acrylate, vinyl acetate, acrylic acid, acrylamide and methylol acrylamide, (12) methyl methacrylate, ethyl acrylate, acrylamide and methylol acrylamide, and (13) ethyl acrylate, acrylonitrile, itaconic acid and methylol acrylamide.  In making coating compositions a dispersion of a copolymer of vinyl toluene, ethyl acrylate and methacrylamide and a titanium dioxide/zinc sulphide/barium sulphate pigment mixture are added to the dispersion of (1), a titanium dioxide/lithopone/mica/silica pigment mixture is added to the dispersions of (6), (7) and (10), zinc oxide is added to the dispersion of (8), and copper phthalocyanine is added to the dispersion of (9).ALSO:Surfaces of chipboard, asbestos-cement, wood, steel, glass, concrete, and paper, are coated by applying thereto by dipping, spraying, brushing, roller-coating or blade application, a copolymer derived from (A) N-methylol acrylamide, methacrylamide or maleimide, (B) a monomer containing a group reactive with N-methylol groups, and (C) a monomer compatible with (A) and (B), the total amount of (A) and (B) not exceeding 4,5% by weight of the copolymer. After application, which is preferably from aqueous dispersion, the copolymer coatings are thermoset by heating at 240-750  DEG F.  In the examples: (2) chipboard and papers are coated with an aqueous dispersion containing a copolymer of vinyl toluene, ethyl acrylate, methacrylamide and N-methylol methacrylamide, and a copolymer of vinyl toluene, ethyl acrylate and methacrylamide, (3) asbestos-cement sheets are coated with a dispersion as in (2), which may also contain a mixture of titanium dioxide, zinc sulphide and barium sulphate, and (10) surfaces of wood, steel, glass, concrete and asbestos-cement are coated with an aqueous dispersion of a copolymer of vinyl acetate, acrylic acid, N-methylol acrylamide, acrylamide and ethyl acrylate containing titanium dioxide, lithopone, mica and silica.ALSO:The examples describe dyeing a fabric and impregnating a paper, as follows:- (9) cotton percale is dyed by padding it with an aqueous dispersion of a copolymer of vinylidene chloride, ethyl acrylate, 2-ethylhexyl acrylate, methacrylamide and or-methylol methacrylamide containing copper phthalocyanine pigment, followed by drying and heating at 300 DEG F, and (11) a paper is impregnated with a dispersion of a copolymer of ethyl acrylate, acrylamide and N-methylol acrylamide, dried, and heated at 300 DEG F. to provide a paper of increased strength.