ENFASIGA FILMBILDANDE FOTOTVERBINDBARA SYSTEM INNEHALLANDE ALLYLESTERHARTS OCH N-MALEINIMIDHALTIG FORENING

1377816 Photo curable, unsaturated monomer-containing coating compositions SIEMENS AG 21 June 1972 [22 June 1971] 29183/72 Headings C3P C3R and C3B [Also in Division G2] A composition which can be dissolved in a solvent to provide a solution for forming photocurable coatings, comprises at least one filmforming resin containing one or more allyl ester groups, and at least one compound containing one or more maleimido groups, the ratio of allyl double bond equivalents to maleimido double bond equivalents being #1. A photo-sensitizer may also be present. The maleimido compound may preferably be an N-aryl maleimide which is alkyl substituted in the 0 position, or an N,N1- arylene bis-maleimide which is o-, or o,o1-alkyl substituted, although other maleimides may also be used. Specific examples are N-cyclohexyl-, N-phenyl- and N-o-tolyl maleimide, and N,N1 - o - tolylidene - bis - maleimide. The maleimide compound acts as comonomer and photo-initiator. Examples of sensitizers are Michler's ketone, 4,41-bis-diethylaminobenzophenone, 2 - t. - butyl - 9,10 - anthraquinone, 1,2 - benz - 9,10 - anthraquinone, 2 - keto - 3- methyl - 1,3 - diazabenzanthrone, and pnitrodiphenyl, these being especially suited to U.V. light. In the examples, the following solutions are coated on to aluminium foils and exposed: diallyl phthalate prepolymer dissolved in chloroform together with: (1) and (2) N- phenyl maleimide and Michler's ketone; (3) and (4) N - o - tolyl maleimide and Michler's ketone; (5) N-o-tolyl maleimide (no sensitizer); (b) N,N1 - p,p '- diphenyl methane - bis - maleimide and Michler's ketone and (7) N-cyclohexyl maleimide and Michler's ketone. Also exemplified are the following solutions which are coated and exposed in the same way: (8) diallyl isophthalate prepolymer, N - o - tolyl maleimide and 2-t.-butyl-9,10-anthraquinone in toluene; (9) allyl methacrylate prepolymer, N-o-tolyl maleimide and Michler's ketone in chloroform. In Examples 10 and 11, an unsaturated polyester is prepared by polycondensing the reaction product of hexahydrophthalic acid mono allyl ester and bisphenol-A-bis-glycidyl ether, with terephthalic acid dichloride. This is dissolved in chloroform with N-phenyl maleimide and Michler's ketone and cured as before. In Example 12 the reaction product of hexahydrophthalic acid monoallyl ester and bisphenol-A-bis-glycidyl ether was polymerized with diphenyl methane-4,41-diisocyanate to obtain a polyurethane containing allyl groups. This is dissolved