| 摘要 |
45916 CAN 1A This invention relates to abrasive products having a resinous binder. The abrasive products can be bonded abrasives, coated abrasives, or nonwoven abrasives. In the manufacture of coated abrasives, the make coat and abrasive grains are first applied to the backing, then the size coat is applied, and finally, the construction is fully cured. Generally, thermally curable binders provide coated abrasives with excellent properties, e.g., heat resistance. In order to obtain the proper coating viscosities, solvent is commonly added to these resins. When polyester or cellulosic backings are used, curing temperature is limited to about 130.degree.C. At this temperature, cure times are long. The long cure time along with the solvent removal necessitates the use of festoon curing areas. Disadvantages of festoon curing areas include the formation of defects at the suspension rods, inconsistent cure due to temperature variations in the large festoon ovens, sagging of the binder, wrinkling of very flexible webs, and shifting of abrasive grains. Furthermore, festoon curing areas require large amounts of space and enormous amounts of energy. Radiation curing processes have been used in an attempt to avoid the disadvantages of festoon ovens. This invention provides abrasive products comprising abrasive grains bonded together or bonded to a backing by means of a binder comprising an oligomeric aminoplast resin having on average at least one pendant .alpha.,.beta.-unsaturated carbonyl group per oligomeric unit. The oligomeric aminoplast resins polymerize via free radical polymerization at the site of the .alpha.,.beta.-unsaturation. Polymerization is initiated by a source of free radicals. The source of free radicals can be generated by electron beam radiation or by an appropriate curing agent or initiator upon exposure to heat or radiation energy. The coated abrasive of this invention demonstrates improved grinding performance under severe conditions as compared with coated abrasives comprising radiation curable resins heretofore known.
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