| 摘要 |
1407652 Self-lubricating polymer compositions MINNESOTA MINING & MFG CO 6 Feb 1973 [7 Feb 1972] 5887/73 Heading C3R Self-lubricating polymer compositions comprise 100 parts by weight of a thermoset polyisocyanurate polymer having sufficient isocyanurate cross-linking groups therein such that the polymer retains at least 60% of its room temperature hardness after 1 hour at 350‹ F. and homogeneously dispersed therein, from 1 to 40 parts by weight of an inert lubricant which is a non-volatile liquid in at least part of the temperature range from 100‹ F. to the degradation temperature of the polymer. Preferably the polyisocyanurate polymer also contains urethane groups and is prepared by reacting a polyisocyanate and a polyol in the presence of a catalyst which is capable of trimerizing isocyanate groups. The polyisocyanate and polyol may be prereacted before trimerization takes place. Suitable lubricants are low melting thermoplastic polymers such as polyethylene, petroleum based oils and greases, silicone oils, waxes, particularly paraffin waxes with an inherent coefficient of friction of 0À08 to 0À12, and high molecular weight polyether glycols. The compositions may be used in the production of machine parts, e.g. bearings, cams and gears. |
