Unsaturated polyester resin composition, molding material, molded article, and battery pack casing for electric vehicle

An unsaturated polyester resin composition comprising:

• an unsaturated polyester, a polymerizable monomer, a low shrinkage agent, aluminum hydroxide, and an electrically conductive filler, wherein
• the unsaturated polyester is a polymerization product of a polybasic acid and a polyhydric alcohol;
• the polybasic acid includes a polybasic acid having an ethylenically unsaturated double bond;
• a mixing ratio of the polybasic acid having an ethylenically unsaturated double bond is 80 mol % or more with respect to 100 mol % of the polybasic acid;
• the low shrinkage agent includes polyvinyl acetate;
• a mixing ratio of the polyvinyl acetate is 3 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total amount of the unsaturated polyester, the polymerizable monomer, and the low shrinkage agent;
• and
• a mixing ratio of the aluminum hydroxide is 50 parts by mass or more and 300 parts by mass or less with respect to 100 parts by mass of the total amount of the unsaturated polyester, the polymerizable monomer, and the low shrinkage agent.