Konica Minolta, Inc.

Yuuki Nagai

Atsushi Takahashi

Akihiro Maezawa

Chie Inui

Natsumi Hirayama

Hideaki Wakamatsu

Natsuki Ito

Keisuke Mizoguchi

An object of the present invention is to provide an abrasive slurry regeneration method capable of efficiently regenerating an abrasive slurry having a high polishing rate. The abrasive slurry regeneration method is an abrasive slurry regeneration method for polishing a polishing target containing silicon oxide as a main component using an abrasive slurry containing abrasive particles and a plurality of kinds of additives and then regenerating a collected abrasive slurry, characterized by including a regeneration step of collecting an additive having a molecular weight of 500 or more and an additive adsorbed by the abrasive particles among additives contained in the collected abrasive slurry together with the abrasive particles while an abrasive concentration (% by mass) is maintained within a range of 0.2 to 3000% with respect to an abrasive concentration (% by mass) of an unused abrasive slurry when being used for polishing a polishing target.

Abrasive slurry regeneration method

A method for collecting an abrasive from an abrasive slurry which has been used for polishing an object including silicon as a main component includes: (i) adding a solvent to the abrasive slurry; (ii) dissolving particles of the polished object among components of the polished object contained in the abrasive slurry; and (iii) filtering the abrasive slurry to collect the abrasive, in which the steps (i) to (iii) are carried out without a pH adjuster to remove components of the polished object to collect the abrasive.

Recovery method for abrasive

A method for preparing a recycled abrasive slurry includes: polishing a material to be polished, which includes silicon as a main component, with an abrasive slurry including a plurality of kinds of additives added for different purposes; and preparing a recycled abrasive slurry from a collected abrasive slurry collected after the polishing, wherein the recycled abrasive slurry is prepared through: step 1 of removing, from the collected abrasive slurry, at least an additive B capable of decreasing a polishing rate among the plurality of additives, and step 2 of replenishing at least an additive A capable of increasing a polishing rate among the plurality of additives, to the abrasive slurry from which an additive has been removed, which has been prepared in step 1.

Method for preparing recycled abrasive slurry

Method for separating a polishing material, which is capable of separating and recovering cerium oxide from a used polishing material that is mainly composed of cerium oxide and a regenerated polishing material which can be obtained by the separation method. This method for separating a polishing material is characterized in that a divalent alkaline earth metal salt is added into the slurry of the used polishing material, while controlling the temperature of the slurry within the range of 10-70 DEG C., thereby causing the polishing material to aggregate under such conditions that the mother liquor has a pH of less than 10.0 as the pH is converted to one at 25 DEG C. so that the polishing material is separated from the mother liquor.

Method for separating polishing material and regenerated polishing material

A diamond abrasive recovery method in which diamond abrasive is recovered from polishing material slurry including diamond abrasive used for polishing a polishing target mainly composed of silicon. The method comprises (1) recovering polishing material slurry including the used diamond abrasive; (2) adding inorganic salt including a metallic element which is to be a divalent or trivalent cation to the recovered polishing material slurry to aggregate the diamond abrasive and separating a supernatant liquid from a diamond abrasive included dispersion medium; and (3) extracting diamond abrasive from the separated diamond abrasive included dispersion medium using a low polarity dispersion medium.

Diamond abrasive recovery method

Disclosed are polishing material particles which have polishing performance suitable for precision polishing and also have a high polishing speed and high monodispersibility; a polishing material containing the polishing material particles; and a polishing processing method using the polishing material. The polishing material particles are spherical particles having an average aspect ratio of 1.00 to 1.15, wherein the particle diameter (D(nm)) of the polishing material particles as determined from a particle diameter cumulative distribution curve falls within the range from 50 to 1500 nm. The average content of cerium or the total content of cerium and at least one element selected from lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm) and europium (Eu) in the polishing material particles is 81 mol % or more relative to the total content of all of rare earth elements that constitute the polishing material particles.

Polishing material particles, method for producing polishing material, and polishing processing method

Technique to provide an abrasive regeneration method which, from a used abrasive, can recover an abrasive by an efficient method and can thereafter obtain a high-purity regenerated abrasive by a simple method. This abrasive regeneration method uses an abrasive comprising at least one type of abrasive selected from diamond, boron nitride, silicon carbide, alumina, alumina zirconia, zirconium oxide and cerium oxide. The abrasive regeneration involves a slurry recovery step (A) for recovering an abrasive slurry discharged from a polishing machine, a separation and concentration step (B) for adding an alkaline earth metal salt as an inorganic salt to the recovered abrasive slurry to aggregate the abrasive, and separating and concentrating the abrasive from a mother liquor, an abrasive recovery step (C) for recovering the separated and concentrated abrasive, and a second concentration step (D) for filter-treating the concentrated abrasive.

Abrasive regeneration method

Abrasive material regeneration method regenerates a cerium oxide abrasive material from a used abrasive material slurry containing the cerium oxide abrasive material and resulting from grinding a grinding subject having silicon as the primary component, characterized by regenerating the abrasive material containing cerium oxide through: a slurry recovery step (A) for recovering an abrasive material slurry discharged from a grinder; an isolation/concentration step (B) for adding a magnesium salt as an inorganic salt to the recovered abrasive material slurry, aggregating the abrasive material under the condition that the pH value of the mother liquor converted to 25 DEG C is at least 6.5 and less than 10.0, and thus isolating and concentrating the abrasive material from the mother liquor; and an abrasive material recovery step (C) for recovering the isolated and concentrated abrasive material.

Abrasive material regeneration method and regenerated abrasive material

Technique to provide an abrasive regeneration method which, from a used abrasive slurry, can recover an abrasive by an efficient method and can thereafter obtain a high-purity regenerated abrasive by a simple method. This abrasive regeneration method uses an abrasive comprising at least one type of abrasive selected from diamond, boron nitride, silicon carbide, alumina, alumina zirconia and zirconium oxide. The abrasive regeneration involves a slurry recovery step (A) for recovering an abrasive slurry discharged from a polishing machine, a separation and concentration step (B) for adding an alkaline earth metal salt as an inorganic salt to the recovered abrasive slurry to aggregate the abrasive, and separating and concentrating the abrasive from a mother liquor, and an abrasive recovery step (C) for recovering the separated and concentrated abrasive.

Provided are fine abrasive particles which have a high rate of polishing and generate few polishing flaws. A process for producing then abrasive particles is also provided in which the fine abrasive particles have a reduced coefficient of fluctuation in particle diameter, the production steps are simple, and the production cost is low. The fine abrasive particles comprise cerium oxide, at least one element selected from La, Pr, Nd, Sm, and Eu, and one or more element selected from Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and are characterized in that the cerium oxide has a Ce content of 20 mol % or higher and that the sum (mol %) of the content of the at least one element selected from La, Pr, Nd, Sm, Nd Eu and the content of Ce in the cerium oxide is greater than the sum (mol %) of the contents of the one or more elements selected from Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

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Tachikawa, Japan

Yuuki Nagai