| abstract |
An unsaturated polyester resin composition which comprises an unsaturated polyester, a polymerizable monomer, a shrinkage-reducing agent, and aluminum hydroxide. The unsaturated polyester is a product of polymerization of one or more polybasic acids with one or more polyhydric alcohols. The polybasic acids comprise an unsaturated polybasic acid, the proportion of the unsaturated polybasic acid being 80 mol% or higher per 100 mol% the polybasic acids. The shrinkage-reducing agent comprises poly(vinyl acetate), and the poly(vinyl acetate) is contained in an amount of 3-10 parts by mass per 100 parts by mass of the sum of the unsaturated polyester, the polymerizable monomer, and the shrinkage-reducing agent. The aluminum hydroxide is contained in an amount of 150-300 parts by mass per 100 parts by mass of the sum of the unsaturated polyester, the polymerizable monomer, and the shrinkage-reducing agent. |