| 摘要 |
A heat curable composition, comprising: A. a blocked polyurethane obtainable by reaction of a hydroxyl functional hydrogenated polydiene or polyolefin intermediate with at least 1.8 equivalents of a polyisocyanate for each equivalent of said hydroxyl functional intermediate, and blocking with a blocking agent, the equivalent ratio of said polyisocyanate to said blocking agent being from about 0.5 to about 2.0, said hydroxyl functional intermediate having on average at least 1.5 hydroxyl groups per molecule and a number average molecular weight of from about 500 to about 15,000; B. a crosslinking agent having -NH2, -NHR<6> (where R<6> is an alkyl having from 1 to 4 carbon atoms), -OH, or -SH curing groups, the amount of crosslinking agent being such that the ratio of blocked isocyanate groups to curing groups is from about 0.8 to about 4.0, and C. from about 1 to about 100 parts by weight of silicone oil per 100 parts by weight of blocked polyurethane. Also, methods of preparation of the compositions, and their use as low-friction abrasion-resistant coatings, particularly on EPDM glass run channels for automobiles. |
