process for the preparation of compounds, which are suitable for the manufacture of various products formed in the heat with a ge small wrijvingscoefficient,a method for the design of these compositions, and products obtained thereby formed.

摘要

1440550 Polyimides RHONE-POULENC SA 27 Nov 1974 [28 Nov 1973] 51449/74 Heading C3R A mouldable composition comprises (by weight): (a) 40 to 80% of a prepolymer prepared from a bisimide where A is and T is -O-, -CH 2 -, -SO 2 - or and from a diamine H 2 N-B-NH 2 where B is an organic redical as defined for A; (b) 10 to 50% of a filler at least 50% of which is a slip material, and (c) 5 to 25% of a lithium salt of a C 6 -C 25 saturated or ethylenically unsaturated aliphatic monocarboxylic acid, which salt does not melt at below 180‹ C. Specified fillers are as slip agents: graphite, MoS 2 and P.T.F.E. of 0À1 to 50Á; as reinforcing fillers: glass, asbestos, potassium titanate, carbon, P.T.F.E., polyamide and polyamide-imide fibres of 0À5 to 20 mm. length and glass microspheres; and as general fillers Ca, Zn and Fe oxides, Cu, Pb and Ag particles, BaSO 4 , mica, litharge and clay. Specificed lithium salts are the octoate, laurate, palmitate and stearate. Articles moulded from the optionally pelleted composition are useful as transmission bearings, bearings for domestic electrical appliances and as self-lubricating discs for compressors with an eccentric rotor. Reference has been directed by the Comptroller to Specifications 1,342,565, 1,263,234 and 1,190,718.