| abstract |
(57) [Summary] [PROBLEMS] To provide excellent productivity without using a reinforcing agent. A branched polyoxymethylene that significantly improves stiffness and creep, improves thermal stability, and has excellent dimensional accuracy. To provide a copolymer and a resin composition thereof. SOLUTION: 100 parts by mass of trioxane (a), 0.001 to 20 parts by mass of a monofunctional glycidyl compound (b), and 0 to 10 parts by mass of a cyclic ether and / or cyclic formal (c) are used together using a cationic polymerization catalyst. In a polyoxymethylene copolymer having a branch composed of an oxymethylene unit (—CH 2 O—) obtained by polymerization and an oxyalkylene unit represented by the following general formula (1), A branched polyoxymethylene copolymer, wherein the ratio of n = 1 is 95 mol% or more of the whole oxyalkylene units, and the ratio of n ≧ 2 is less than 5 mol% of the whole oxyalkylene units. Embedded image (In the formula, n ≧ 1, R 0 is hydrogen or a molecular weight of 15 to 2,0. Represents an organic group of 00. ) |