Patent GB-1339988-A (GB)
Title: Acrylic resinous composition
IPC: C08L51/00
Filed: 1971-04-19
Abstract: 1339988 Acrylic resinous compositions MITSUBISHI RAYON CO Ltd 19 April 1971 [18 March 1970 3 April 1970 28 Dec 1970] 24477/71 Heading C3P An acrylic resinous composition consists essentially of (A) 5 to 35% by weight, based on the weight of the composition, of a component containing in polymerized form 60 to 100% by weight of at least one C 1-8  alkyl acrylate and 0 to 40% by weight of at least one copolymerizable monofunctional vinyl or vinylidene monomer, and being cross-linked with a cross-linking agent to the extent of exhibiting a swelling degree of 3 to 15 and a gel content of no less than 80%, (B) 1 to 70% by weight of a component prepared by polymerizing, in the presence of component (A), 10 to 60% by weight of at least one C 1-8  alkyl acrylate, 40 to 90% by weight of at least one C 1-4  alkyl methacrylate, and 0 to 20% by weight of at least one copolymerizable vinyl or vinylidene monomer, and (c) the remainder of a component prepared by polymerizing, in the presence of (A) and (B), 60 to 100% by weight of at least one C 1-4  alkyl methacrylate, and 0 to 40% by weight of at least one copolymerizable monofunctional vinyl or vinylidene monomer. The cross-linking agent may be at least one peroxide and/or at least one polyfunctional monomer having two or more non-conjugated carbon-carbon double bonds in the molecule, preferably an oil-soluble organic peroxide used in an amount of 0À3 to 3À0 parts by weight per 100 parts of (A), or at least one of triallyl phosphate, trimethylol propane trimethacrylate, allyl acrylate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, allyl methacrylate, tetraethylene glycol dimethacrylate and ethylene glycol dimethacrylate, used in amounts of 0À2 to 15 parts by weight per 100 parts of (A). The copolymerizable monomer used to prepare (A) may be methacrylic acid, a C 1-12  alkyl methacrylate, a di(C 1-10 ) alkyl) itaconate, acrylonitrile, methacrylonitrile, vinylidene chloride, vinyl chloride, styrene or an alkylsubstituted styrene. The copolymerizable monomer used to prepare (C) may be acrylic acid, a C 1-12  alkyl acrylate, a di(C 1-10  alkyl) itaconate, acrylonitrile, methacrylonitrile, vinylidene chloride, vinyl chloride, styrene or an alkylsubstituted styrene. The polymerization of components (B) and/or (C) may be carried out in aqueous emulsion in the presence of 0À01 to 2 parts by weight per 100 parts of monomer or monomer mixture of at least one chain transfer agent, such as a C 2-20  alkyl mercaptan, a mercaptocarboxylic acid, a C 2-12  alkyl mercaptocarboxylate, benzyl mercaptan or thiophenol. An acrylic resinous composition may comprise 60 to 99À9% by weight of an acrylic resinous composition of the invention and 0À1 to 40% by weight of a vinylidene fluoride polymer. Suitable vinylidene fluoride polymers are homopolymers of vinylidene fluoride, and copolymers containing up to 10% by weight of a copolymerizable monomer such as sym-dichlorofluoroethylene, 1,1,2-trifluoro-2-chloroethylene, tetrafluoroethylene, vinyl fluoride, vinyl chloride and other ethylene halides. In the examples polymer (A) is a cross-linked polybutyl acrylate, copolymer of butyl acrylate with methyl methacrylate, styrene, acrylonitrile or butyl methacrylate, or 2-ethylhexyl acrylate/methyl methaerylate copolymer; polymer (B) is a butyl acrylate/methyl methacrylate copolymer; and polymer (C) is a butyl acrylate/methyl methacrylate copolymer or a butyl acrylate/ methyl methacrylate/methacrylic acid terpolymer.