The use of halogen-containing benzophenone derivatives as curing catalysts activated by ultraviolet light, to syrehærdnende resins and resin blends.

摘要

1304725 UV-hardened resin compositions BAYER AG 10 Sept 1970 [18 Sept 1969] 43368/70 Heading C3R [Also in Division G2] An acid-hardening resin composition contains, as UV-activated hardening catalyst, at least one halogenated benzophenone wherein R 1 represents -CH 2 X, -CHX 2 or -CX 3 and R 2 represents -H, -CH 3 , -CH 2 X, -CHX 2 or -CX 3 , X being a halogen atom. Suitable halogenated benzophenones are pbenzoyl- -benzyl chloride, -benzal chloride, and -benzotrichloride, 4 : 4SP1/SP-bis-(chloromethyl, dichloromethyl, or trichloromethyl) benzophenone, the corresponding bromocompounds, and o-benzoylbenzotrichloride, preferably used in amounts of 0À1-10% by weight of the resin. Suitable resins are phenolic, urea-formaldehyde, melamine-formaldehyde and epoxy resins. In Example 1 a 40 : 60 mixture of a urea-formaldehyde resin and an alkyd resin (from castor oil, soya bean oil, trimethylolpropane, pentaerythritol, benzoic acid and phthalic anhydride) dissolved in butanol/ethoxyethanol/ethanol, with 1% of silicone oil in xylene, is coated on to glass and hardened by exposure to UV light, after the addition of 1À6-2À3% of 4 : 4SP1/SP-bisbromomethyl - benzophenone, p - benzoylbenzyl bromide, p-benzoyl-benzal bromide or chloride, or p-benzoyl-benzotrichloride. In Example 2 a 12 : 88 solution of hexamethoxymethylmelamine and a polyester (from terephthalic acid and bisphenol A bis-hydroxyethyl ether and glycerol) in methylene chloride, with 3% of p-benzoyl-benzotrichloride is coated on to a metal plate and exposed after drying to UV light through a negative; after heating the unexposed portions are removed with CH 2 Cl 2 .