| abstract |
PROBLEM TO BE SOLVED: To provide a method for producing an unsaturated polyester having low viscosity, good handleability and high safety, and an unsaturated polyester resin composition using the unsaturated polyester and having excellent hot water resistance. Offer things. SOLUTION: A first step of reacting dicyclopentadiene (C) with a reaction mixture of maleic anhydride (A) and water (B), a reaction mixture of the first step, a polyhydric alcohol or a polyhydric alcohol By reacting the alcohol with the polybasic acid, A second step of obtaining an unsaturated polyester modified with dicyclopentadiene (C), wherein the molar ratio of water (B) to maleic anhydride (A) (B / A) is set to 1 or less, and a resin composition containing the unsaturated polyester. |