GB857956A - Improvements relating to methyl methacrylate polymers - Google Patents

Abstract

Copolymers are made which contain, combined in each 100 parts by weight of polymer chain, at least 30 parts of methyl methacrylate, 10 to 50 parts of monocarboxylic acid modified ethylenically unsaturated alkyd resin and 0,2 to 20 parts, exclusive of amino residue of the radical: <FORM:0857956/IV(a)/1> wherein one R is a hydroxyl group or a negatively charged oxygen atom and the other R is an amino residue of ammonia or a monoamine bonded through amino nitrogen. Alkyl resins specified are: (1) the product obtained by reacting coconut oil, ethylene glycol, phthalic anhydride and methacrylic acid, and (ii) the product obtained by reacting ethylene glycol, glycerine, phthalic anhydride, p-t-butyl benzoic acid and methacrylic acid. The copolymers may be made by copolymerizing the modified alkyd resin, methyl methacrylate and glycidyl methacrylate, and, if desired, a small proportion of another ethylenically unsaturated monomer, and reacting the resulting copolymer with ammonia or a monoamine; alternatively the glycidyl methacrylate may be reacted with ammonia or a monoamine before copolymerization. Copolymerizable monomers specified are methyl, butyl and ethylhexyl acrylates, butyl and lauryl methacrylates, acrylonitrile, styrene, vinyl acetate and vinyl chloride. Monoamines specified are ethylamine, t-butylamine, t-octylamine, dimethylamine, methylethylamine, mono - di - and tri - ethanolamines, dimethylbenzylamine, N - methyl morpholine and dimethylpalmitylamine. Polymerization may be carried out in solution with the aid of catalysts such as benzoyl peroxide, di - t - butyl peroxide, cumene hydroperoxide, azobisisobutyronitrile, diacetyl peroxide and dilauroyl peroxide. The resulting copolymers may be used in coating applications in the form of their solutions in solvents such as toluene and mixtures of toluene with xylene or isopropyl alcohol together with other film forming agents such as polymers and copolymers of methyl, ethyl and butyl methacrylates, vinyl acetate, vinyl chloride and acrylonitrile, cellulose acetatebutyrate and alkyd resins and pigments such as metal oxides, e.g. titanium dioxide, hydroxides, chromates, silicates, sulphides, sulphates and carbonates, carbon blacks, metal flake pigments and organic pigments.ALSO:Substrates of wood, metal or glass are coated with copolymers which contain combined in each 100 parts of polymer chain at least 30 parts of methyl methacrylate, 10 to 50 parts of a monocarboxylic acid modified ethylenically unsaturated alkyd resin and 0.2 to 20 parts, exclusive of amino residue, of the radical: <FORM:0857956/III/1> wherein one R is a hydroxyl group or a negatively charged oxygen atom and the other R is an amino residue of ammonia or a monoamine bonded through amino nitrogen (see Group IV(a)). The copolymers are used in the form of solutions in solvents such as toluene, and mixtures of toluene with xylene or isopropyl alcohol. The coating compositions may be applied by conventional methods and dried at room or elevated temperatures. Optional ingredients of the compositions are film forming agents such as polymers and copolymers of methyl, ethyl and butyl methacrylates, vinyl acetate, vinyl chloride and acrylonitrile, cellulose acetate butyrate and alkyd resins, and pigments such as metal oxides, e.g. titanium dioxide, hydroxides, chromates, silicates, sulphides, sulphates and carbonates, carbon blacks, metal flake pigments and organic pigments. The examples describe the application of coatings on steel panels which have been treated with a rust inhibitor and then prime coated.