Dual cured abrasive articles

#The invention relates to an abrasive article, and a method of making and using the abrasive article. Abrasive articles have been utilized to abrade and finish workpiece surfaces for well over a hundred years. These applications have ranged from high stock removal, and high pressure metal grinding processes to fine polishing of ophthalmic lenses and primed surfaces. In general, abrasive articles comprise a plurality of abrasive particles bonded either together (e.g., a bonded abrasive or grinding wheel) or to a backing (e.g., a coated abrasive). For a coated abrasive there is typically a single, or sometimes two layers of abrasive particles. Once these abrasive particles are worn, the coated abrasive is essentially worn out and is typically discarded.

#One way to extend the life of a coated abrasive has been to use a three-dimensional coating. A three-dimensional coating of abrasive particles is exemplified in U.S. Pat. No. 5,152,917 (Pieper et al.). Pieper reports a three-dimensional structured abrasive that results in a relatively high rate of cut and a relatively fine surface finish on the workpiece surface. The abrasive comprises non-random, precisely shaped abrasive composites that are bonded to a backing.

#One method of providing a three-dimensional, textured, fixed abrasive article is generally as follows. A slurry containing a mixture of a binder precursor and a plurality of abrasive particles is coated onto a production tool having cavities that are the negative of the desired shape of the textured surface. A backing is brought into contact with the exposed, coated surface of the production tool such that the slurry wets the surface of the backing. Then, the binder may be first at least partially solidified, cured, or gelled. The abrasive article is then removed from the production tool and subsequently fully cured if it was not fully cured in the previous first cure. Alternatively, the slurry may be applied onto the surface of the backing and then the production tool may be brought into contact with the slurry coated on the backing. The abrasive layer thus comprises a plurality of abrasive “composites” on a backing.

#The present invention provides a three-dimensional fixed abrasive article having a consistent cure throughout the thickness of the abrasive layer. This provides an erodible abrasive article throughout the worklife.

#Abrasive Article

#In general, abrasive particles are dispersed in a binder precursor to form an abrasive layer and/or abrasive composites bonded to a backing. The abrasive article comprises a backing having a front surface. The abrasive layer is attached on the front surface of the backing. The abrasive layer is three-dimensional and comprises a plurality of abrasive composites. In some embodiments, abrasive composites are shaped as pyramids. There are recesses or valleys between adjacent abrasive composites. There may be more than one row of pyramidal abrasive composites, and the second row of abrasive composites may be offset from the first row. The abrasive composites comprise a plurality of abrasive particles dispersed in a binder. Optionally, the abrasive article does not have to have a separate backing.