GB853886A - Improvements relating to methacrylate polymers - Google Patents

Abstract

Copolymers of methyl methacrylate are prepared having a relative viscosity of 1,117 to 1,196 and containing in the polymer chain the radical: <FORM:0853886/IV(a)/1> wherein in one R is a hydroxyl group and the other R is an amino residue of ammonia or a monoamine bonded through amino nitrogen, the radical, exclusive of amino residue, constituting 0,2% to 3% by weight of the polymer. The copolymers may be prepared either (1) by copolymerizing methyl methacrylate, glycidyl methacrylate and if desired another ethylenically unsaturated monomer inert towards the above radical, e.g. methyl acrylate, ethyl, propyl and butyl acrylates and methacrylates, lauryl methacrylate, acrylonitrile, vinyl acetate and styrene, and reacting the resulting copolymer with ammonia or a monoamine, or (2) reacting the glycidyl methacrylate with ammonia or a monoamine before the copolymerization and omitting the subsequent amination. The copolymerization and amination take place for a time and under conditions such that a polymer of the desired viscosity is produced, e.g. as described in Specifications 763,158 and 807,895. The examples describe the preparation of copolymers by a solution polymerization process employing benzoyl peroxide or azobisisobutyronitrile as a catalyst. Monoamines specified are dimethylamine, methylethylamine, ethylamine, ethanolamine, diethanolamine, t-butylamine and t-octylamine. The copolymers are used for coating purposes in the form of solutions in solvents such as toluene, toluene-methyl ethyl ketone-butanol, toluene-isopropyl alcohol and toluene-acetone-isopropyl alcohol. Specification 853,885 also is referred to.ALSO:Amino-hydroxypropyl methacrylates are made by reacting ammonia or a monoamine with glycidyl methacrylate, amines specified being ethylamine, t-butylamine, t-octylamine, ethanolamine, diethanolamine, dimethylamine and methylethylamine. In an example (7) 3-t-butylamino-2-hydroxypropyl methacrylate is prepared by adding glycidyl methacrylate to a solution of t-butylamine in water, followed by the removal of water and unreacted amine and distillation and recrystallisation of the ester product. Specifications 763,158, 807,895 and 853,885 are referred to.ALSO:Substrates of steel, tin plate, aluminium or glass are coated with copolymers of methyl, methacrylate having a relative viscosity of 1.117 to 1.196 and containing in the polymer chain the radical: <FORM:0853886/III/1> wherein one R is a hydroxyl group and the other R is an amino residue of ammonia or a monoamine bonded through nitrogen (see Group IV(a)). In examples: (1) the side seams of food cans are coated, shortly after soldering, with a toluene-isopropyl alcohol solution of a methyl methacrylate copolymer in which the amino group in the above radical is derived from ammonia; and (2) steel panels prime coated with a pigmented soya bean oilmodified glycerol phthalate alkyd resin ore coated with a toluene-methyl ethyl ketonebutanol solution of a methyl methacrylate copolymer in which the amino group in the above radical is derived from ethanolamine, followed by baking at 93 DEG C. for 30 minutes. Specifications 763,158, 807,895 and 853,885 are referred to.