Abstract: A polishing material is provided in which the dispersibility of the abrasive grains of the polishing material having, as a major component, rare earth oxides including cerium oxide is made better and the hardness of abrasive grain precipitates is reduced, and at the same time high efficiency of polishing can be achieved stably. According to the present invention, in a polishing material having, as the major component, rare earth oxides including cerium oxide, any one of crystalline cellulose, calcium secondary phosphate, a condensate of sodium &bgr;-naphthalenesulphonate and formalin, and synthetic silica is contained as an anti-solidification agent capable of softening abrasive grain precipitates of the polishing material when the abrasive grains of the polishing material are dispersed into a dispersion medium, and sodium hexametaphosphate or pyrophosphate is contained as a dispersant capable of dispersing the abrasive grains of the polishing material into the dispersion medium.

Abstract: The present invention provides a method of examining quality of cerium-based abrasives which can simply determine their grinding characteristics. Specifically, the method employs X-ray diffractometry to examine qualities based on, for example, B/A wherein A and B are peak intensities relevant to LnxOy and LnF3, respectively. The present invention further provides: a method of producing a cerium-based abrasive which can give cerium-based abrasive with specific grinding characteristics; and a cerium-based abrasive which has specific grinding characteristics for specific purposes.

Abstract: Regarding a cerium oxide-based abrasive containing cerium oxide as a main component and abrasive particles with an average particle diameter of 0.2 to 3.0 &mgr;m, the present invention provides a cerium-based abrasive containing coarse particles of 10 &mgr;m or larger in a concentration of 1000 ppm or lower (by weight) or magnetic particles in a concentration of 1000 ppm or lower (by weight). The coarse particles or the magnetic particles are particularly preferable to exist in a concentration of 300 ppm or lower (by weight). Further, by controlling an average value of the specific surface area of the abrasive particles to be within 0.5 to 30 m2/g, the resulting abrasive is provided with a high cutting property and is capable of forming a polished face with high precision. The production method of such cerium-based abrasives comprises control being the concentration of the coarse particles and the classification point and repeated classification.

Abstract: A polishing material is provided in which the dispersibility of the abrasive grains of the polishing material having, as a major component, rare earth oxides including cerium oxide is made better and the hardness of abrasive grain precipitates is reduced, and at the same time high efficiency of polishing can be achieved stably. According to the present invention, in a polishing material having, as the major component, rare earth oxides including cerium oxide, any one of crystalline cellulose, calcium secondary phosphate, a condensate of sodium &bgr;-naphthalenesulphonate and formalin, and synthetic silica is contained as an anti-solidification agent capable of softening abrasive grain precipitates of the polishing material when the abrasive grains of the polishing material are dispersed into a dispersion medium, and sodium hexametaphosphate or pyrophosphate is contained as a dispersant capable of dispersing the abrasive grains of the polishing material into the dispersion medium.

Abstract: The present invention provides a method of examining quality of cerium-based abrasives which can simply determine their grinding characteristics. Specifically, the method employs X-ray diffractometry to examine qualities based on, for example, B/A wherein A and B are peak intensities relevant to LnxOy and LnF3, respectively. The present invention further provides: a method of producing a cerium-based abrasive which can give cerium-based abrasive with specific grinding characteristics; and a cerium-based abrasive which has specific grinding characteristics for specific purposes.

Abstract: There is provided a cerium-based abrasive which enables formation of a highly accurate polished surface and has improved grindability. There is also provided a method of evaluating cerium-based abrasives in a relatively easy manner. In order to achieve the above objects, the cerium-based abrasive of this invention is a cerium-based abrasive containing 40% by weight or more of cerium oxide (on the basis of the total weight of rare earth oxides) which is characterized by further containing 0.5 to 10% by weight of fluorine per 100% by weight of the cerium-based abrasive, in terms of atomic weight, and polishing particles consisting of crystals with a lattice constant measured by an X-ray powder diffraction method ranging from 0.544 to 0.560 nm.

Abstract: The present invention provides a stock material for cerium-based abrasives which can be sintered at a relatively low roasting temperature without causing abnormal growth of the particles. More concretely, the stock material for cerium-based abrasives is produced by calcinating the carbonate of rare earth at a given temperature level to partly convert it into the oxide of rare earth in such a way to produce the mixed stock material having a loss on ignition of 0.5 to 25% on a dry basis, determined by heating at 1000° C. for 1 hour.

Abstract: There is provided a cerium-based abrasive which enables formation of a highly accurate polished surface and has improved grindability. There is also provided a method of evaluating cerium-based abrasives in a relatively easy manner. In order to achieve the above objects, the cerium-based abrasive of this invention is a cerium-based abrasive containing 40% by weight or more of cerium oxide (on the basis of the total weight of rare earth oxides) which is characterized by further containing 0.5 to 10% by weight of fluorine per 100% by weight of the cerium-based abrasive, in terms of atomic weight, and polishing particles consisting of crystals with a lattice constant measured by an X-ray powder diffraction method ranging from 0.544 to 0.560 nm.

Abstract: Regarding a cerium oxide-based abrasive containing cerium oxide as a main component and abrasive particles with an average particle diameter of 0.2 to 3.0 &mgr;m, the present invention provides a cerium-based abrasive containing coarse particles of 10 &mgr;m or larger in a concentration of 1000 ppm or lower (by weight) or magnetic particles in a concentration of 1000 ppm or lower (by weight). The coarse particles or the magnetic particles are particularly preferable to exist in a concentration of 300 ppm or lower (by weight) . Further, by controlling an average value of the specific surface area of the abrasive particles to be within 0.5 to 30 m2/g, the resulting abrasive is provided with a high cutting property and is capable of forming a polished face with high precision. The production method of such cerium-based abrasives comprises control being the concentration of the coarse particles and the classification point and repeated classification.