| abstract |
A polyester having excellent properties for use in a photo solder resist, capable of forming a cured product having particularly excellent flexibility, and being suitably used for a photo solder resist for a flexible printed wiring board. Provide resin. A compound (a) having two epoxy groups in one molecule is reacted with a monocarboxylic acid (b) having one or more ethylenically unsaturated groups in one molecule to obtain an unsaturated compound. A group-containing polyol compound (c) is obtained. Then, a polyol compound (d) other than the unsaturated group-containing polyol compound (c) is reacted with a compound (e) having two acid anhydride groups in one molecule. A polyester resin is obtained by reacting a monoepoxy compound (f) with some carboxyl groups in the obtained compound. [Selection diagram] None |