| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the crack of a penetration part made of a polyacetal type resin by allowing a hard member to penetrate into a molded product made of a polyacetal type resin based on a polyacetal resin having a specific m.p. SOLUTION: A hard member is allowed to penetrate into a molded product made of a polyacetal type resin based on a polyacetal resin with a m.p. of 150-161 deg.C. As the hard member allowed to penetrate, there are a gear, a roller, a grooved roller, a cam roll, a shaft, a pulley, a disc, an axle arm and a composite part of them. When a mixed compsn. of a polyacetal resin and other resin is used, the content of the polyacetal resin is pref. 70wt.% or more. The pref. polyacetal resin is a polyacetal resin of a copolymer containing predetermined mol % of an oxyethylene group derived from 1,3-dioxolan to an oxymethylene group and has a melt index within a predetermined range.</p> |
