| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyacetal resin composition that has excellent mechanical properties, such as rigidity and toughness, and also has excellent performance against discoloration due to retention in a molten state, and a method for producing the same. SOLUTION: The polyacetal resin composition includes: 100 pts.mass of a polyacetal resin (I); 5-50 pts.mass of surface-untreated light calcium carbonate (II) having an average particle diameter of 50-500 nm and pH of 9.2-10.0 according to JIS K5101 test method; a 12-27C monovalent fatty acid (III-I); a 28C or more monovalent fatty acid (III-II), a calcium salt (IV) of a fatty acid, and an ester (V) of an aliphatic alcohol and a fatty acid, wherein a mass ratio [(III-I)+(III-II)/(II)] of the total of the fatty acid (III-I) and the fatty acid (III-II) to the light calcium carbonate (II) is 0.020 to 0.050, a mass ratio [(III-I)+(III-II)/(IV)] of the total of the fatty acid (III-I) and the fatty acid (III-II) to the calcium salt (IV) of a fatty acid is 3 to 15, and a mass ratio (V)/(II) of the ester (V) of an aliphatic alcohol and a fatty acid to the light calcium carbonate (II) is 0.03 to 0.15. COPYRIGHT: (C)2011,JPO&INPIT |
