Patent GB-927791-A (GB)
Title: Polymerization process
IPC: C08F4/12
Filed: 1959-07-23
Abstract: A process for polymerizing esters of acrylic, methacrylic or thiolacrylic acids, the alcohol residues of said esters being free of functional groups reactive in the Zerewitinoff test, or acrylonitrile or methacrylonitrile comprises forming a mixture of (a) monomer, (b) a complex of the monomer with an inorganic halide which is a chloride, bromide or iodide of beryllium, magnesium, calcium, strontium, barium, zinc, cadmium or aluminium, or boron trifluoride, and (c) an organomagnesium compound of formula R-Mg-Y where R is a hydrocarbon group which may contain one or more ether linkages, heterocyclic nitrogen atoms or perfluoroalkyl substituents, and Y is chlorine, bromine, iodine or R, and maintaining the mixture under polymerization conditions. Polymerization is preferably effected in the presence of an inert solvent or diluent, e.g. benzene, toluene, xylene, aromatic naphthas, petroleum ether, n-heptane, n-octane, dichlorethane, trichlorethane, polychloropropanes, methylene chloride, carbon tetrachloride, diethyl ether, dibutyl ether, the dimethyl and diethyl ethers of ethylene glycol, tetrahydrofuran and tetrahydropyran.  The polymer may be recovered by precipitation with methanol and purified by treating with an acid.  Extensive lists of suitable monomers and organomagnesium compounds are given and examples describe the polymerization of methyl methacrylate in toluene in the presence of diphenyl magnesium and (1) magnesium bromide, (2) aluminium chloride, (3) aluminium bromide and iodide, (4) magnesium iodide; (5) dibutyl magnesium with zinc chloride and cadmium bromide; (6) diphenyl magnesium with boron trifluoride and the diethyl etherate thereof; (8) phenyl magnesium bromide and magnesium bromide; (9) n-butyl magnesium chloride and magnesium bromide: (7) the polymerization of methyl methacrylate in n-heptane, diethyl ether and 1,2-dimethoxyethane in the presence of dibutyl magnesium and magnesium bromide: the polymerization in toluene in the presence of diphenyl magnesium and magnesium bromide of (10) isopropyl methacrylate, (11) stearyl methacrylate, (12) benzyl methacrylate, (13) dimethylaminoethyl methacrylate and b -ethoxyethyl methacrylate, and (20) acrylonitrile: (14) the polymerization of n-butyl methacrylate in tetrahydrofuran in the presence of diphenyl magnesium and magnesium bromide: and the polymerisation in toluene of (15) isopropyl acrylate in the presence of diphenyl magnesium and magnesium chloride, bromide and iodide; (16) isopropyl acrylate and t-butyl acrylate in the presence of diphenyl magnesium and aluminium chloride; (17) isopropyl and isobutyl acrylates in the presence of diphenyl magnesium and boron trifluoride; (18) methyl, ethyl and n-propyl acrylates and methyl thiolacrylate in the presence of diphenyl magnesium and magnesium chloride; and (19) cyclohexyl, t-butyl and isobornyl acrylates in the presence of phenyl magnesium bromide and magnesium bromide.  The polymers may be mixed with lubricants, e.g. stearic acid, and light stabilizers, e.g. phenyl salicylate, and moulded.  They may be dissolved in organic solvents to provide lacquers for coating metal, wood, paper, cloth and leather.