To obtain a high-molecular-weight polyester by reacting equimolar amounts of a cyclic acid anhydride with an epoxide and a specified amount of an ethylenically unsaturated monomer in the presence of a basic compound catalyst.
A reactor is charged with 1 mol. of a cyclic acid anhydride having one acid anhydride group, 1 mol. of an epoxide having one epoxy group (e.g. glycidyl methacrylate), below 0.05 mol. of a catalyst comprising a basic compound (e.g. triethylamine), 0.001-0.03 mol. of a polymerization inhibitor (e.g. hydroquinone) and 5-50 wt.%, based on the total weight, ethylenically unsaturated compound (e.g. methyl (meth)acrylate). Next, the atmosphere in the reactor is replaced by an inorganic mixed gas atmosphere (e.g. nitrogen gas) having an oxygen concentration of 3-21 wt.%. The contents are reacted under agitation at a reaction temperature of 100°C or below to obtain a polyester having a number-average molecular weight of 5,000 or above. If required, the polyester is mixed with a photoreaction initiator to obtain a photocurable material.
WATANABE NORIBUMI
UNO MINORU
TAKANO MASUMI
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