COATING POLISHING MATERIAL

摘要

This invention relates to coated abrasive products, and, in particular, to coated abrasive products having a radiation-curable binder. Radiation-curable coated abrasives heretofore known exhibit the shortcoming of poor adhesion of abrasive granules to the backing because the binder does not cure in areas where the granules screen out radiation, unless high dosages of ionizing radiation are employed. High dosages of radiation can adversely affect the backing. The poor adhesion of the abrasive granules results in a large loss of abrasive granules, i.e. "shelling", from the backing upon flexing and grinding. Attempts to improve the adhesion of the abrasive granules by curing by ionizing radiation, e.g., electron beam, through the backside of the backing often leads to degradation of the backing. This invention provides a coated abrasive product and a process for producing same. The coated abrasive product comprises a backing, a make coat, and a size coat, and may contain an optional backsize coat, or any combination of said optional coats, in which at least one coat is formed from a composition curable by electromagnetic radiation comprising: (A) a curable portion containing both ethylenically unsaturated groups and 1,2-epoxide groups, which groups can be in the same compound or in different compounds, and (b) a photoinitiator portion. The photoinitiator portion activates both free-radical and cationic curing mechanisms. The use of the radiation curable composition of this invention overcomes the problem of poor adhesion of abrasive granules resulting from incomplete cure of the binder by combining a cationic curing mechanism with a free-radical curing mechanism.