| 摘要 |
An abrasive article has a web of non-woven fibres interlaced randomly and in crossing contact with each other in which (a) a resilient binder material having a Knoop hardness number of 6 or less is provided joining the fibres together and at the points of contact, the binder comprising a copolymer of an epoxy resin, a polyamide and a long chain polyester resin and in which (b) abrasive grains are resiliently bonded to the fibres by the binder material. Fibres specified are of hog's hair, horse hair, cattle hair, nylon and "Dacron" (Registered Trade Mark) and may be of length 1/2 to 4 inches. The epoxy resin may have an epoxy equivalent of from 170 to 200, the polyamide may be the condensation polymer of dimerized vegetable oils, unsaturated fatty acids and alkyl or aryl polyamines and polyesters have chain lengths of at least 14 members and may be carboxy- or hydroxyl-terminated. The fibres may be curled or crimped before forming into the web and the binder and abrasive grains may be mixed and applied by spraying, dipping or roller coating or the grain added separately by gravity rolling in, or by electrostatic deposition. A second coating of a binder may be applied by spraying, roller coating or dipping. The particles may be applied alternately to both sides followed by a top size coat of binder. The web may then be cured by heating to 325-375 DEG F. for about ten minutes. Reference has been directed by the Comptroller to Specification 1,014,297. |
