2,2-dimethoxy-1,2-DI[4-(meth)acryloyloxy]phenylethane-1-one, method for producing the same, radical polymerization initiator and photocurable composition

#The present invention relates to a novel compound serving as a radical polymerization initiator, which generates radicals through irradiation with light such as a UV ray, to a production method therefor, to a radical polymerization initiator, and to a photocurable composition.

#In UV-curable ink for lithography, flexography, and silk screening, solder resist, etching resist for production of industrial electronic material or the like, color filter resist, UV powder coating, aqueous UV coating, coating with UV-absorber, wood article finish coating, plastics, metal coating, etc., there has been employed a photocurable composition containing a radical-polymerizable compound (i.e., a radical-polymerizable monomer) and a radical polymerization initiator, which generates radicals through irradiation with light such as a UV ray for initiating polymerization of the radical-polymerizable compound. A typical radical polymerization initiator is an acetophenone-type radical polymerization initiator (see Patent Documents 1 and 2).

#One known acetophenone-type radical polymerization initiator is 2,2-dimethoxy-1,2-diphenylethan-1-one. The compound can generate radicals via self-cleavage through irradiation with light such as a UV ray, to thereby initiate polymerization of a radical-polymerizable compound, and is commercially available as IRGACURE 651 (product of BASF). As compared with other acetophenone-type radical polymerization initiators; e.g., 1-hydroxycyclohexyl phenyl ketone (IRGACURE 184, product of BASF) and 2-hydroxy-1-{4-[4-{2-hydroxy-2-methylpropionyl}-benzyl]-phenyl}-2-methylpropan-1-one (IRGACURE 127, product of BASF), 2,2-dimethoxy-1,2-diphenylethan-1-one has higher absorbance to 365 nm light. This property is advantageous, for the compound can effectively utilize i-line (wavelength: 365 nm), which is a predominant component of high-pressure mercury lamps and other industrially useful light sources.

#Hereinafter, the present invention will be described in detail.

#The novel compound of the present invention is a compound represented by the following formula (A):

#(wherein R1 and R2, which may be identical to or different from each other, each represent a hydrogen atom or a methyl group); i.e., 2,2-dimethoxy-1,2-di-[4-(meth)acryloyloxy]phenylethan-1-one.