| 摘要 |
1,147,527. Photopolymerization of acrylic or methacrylic esters. JAPAN GAS-CHEMICAL CO. Inc. 21 July, 1966 [21 July, 1965; 20 Nov., 1965], No. 32779/66. Heading C3P. Esters of the formula where R is hydrogen or methyl, X is hydroxyl or bromine, and n is 1 to 12, optionally in the presence of other vinyl or vinylidene monomers and a photosensitizer, are photopolymerized by subjecting them to irradiation of light of 3800Š or less in wavelength, at a temperature not above 20‹ C. Photosensitizers mentioned are benzoin, benzoin methyl ether, and azobisisobutyronitrile. Suitable types of irradiation are ultraviolet, Schumann, X-ray,γ-ray, and radiation from a mercury arc lamp. The polymerization may be carried out in bulk or in a solvent e.g. ethyl acetate. A two-stage process in which an initial thermal polymerization at 60‹ C. to 50% conversion is followed by a photopolymerization at room temperature of the polymer/monomer mixture, the latter having been coated on glass or metal, is described in Examples 7 and 14. Polymerization of the following monomers is exemplified:-the monomethacrylates and bromohydrin methacrylates of ethylene-, tetraethylene- and polyethyleneglycol (M.W. 300), and of butanediol, the monoacrylates and bromohydrin acrylates of ethylene-, propylene- and polyethylene glycol (M.W. 600), triethylene glycol monoacrylate, diethylene glycol bromohydrin acrylate and propylene glycol monomethacrylate, while comonomers exemplified are methyl methacrylate, styrene, and n-butyl methacrylate.
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