Tama Chemicals Co., Ltd.

Moses Lake Industries, Inc.

Other

Kabushiki Kaisha Toshiba

Tama Chemical Co., Ltd.

Shumpei Shimizu

Toshitsura Cho

Akiko Saito

Naoaki Sakurai

Hideaki Hirabayashi

Shigeo Iiri

Katsuhiro Kato

Osamu Yagi

Mamoru Yoshizako

The copper-based metal polishing composition causes Cu or Cu alloy not to be dissolved at all in immersing Cu or Cu alloy therein, and makes it possible to polish Cu or Cu alloy at a high rate in polishing treatment. Such a copper-based metal polishing composition comprises a water-soluble first organic acid capable of reaction with copper to produce a copper complex compound which is substantially insoluble in water and has a mechanical strength lower than that of copper, at least one second organic acid selected from an organic acid having a single carboxyl group and a single hydroxyl group and oxalic acid, an abrasive grain, an oxidizing agent, and water.

COPPER-BASED METAL POLISHING COMPOSITION, METHOD FOR MANUFACTURING A SEMICONDUCTOR DEVICE, POLISHING COMPOSITION, ALUMINUM-BASED METAL POLISHING COMPOSITION, AND TUNGSTEN-BASED METAL POLISHING COMPOSITION

The invention is a method of processing a waste liquid containing at least an organic quaternary ammonium hydroxide. The waste liquid is brought into contact with a cation-exchanging material so as to make the organic quaternary ammonium ions adsorbed by the material to thereby remove the ions from the liquid (adsorbing step), and optionally the cation-exchanged water obtained by the contact is again processed to separate and remove resist peelings and surfactants therefrom. The invention is also a method of processing the organic quaternary ammonium hydroxide-containing waste liquid for recovering a valuable substance of the organic quaternary ammonium hydroxide therefrom. The method comprises the adsorbing step and an eluting step of bringing an eluent into contact with the cation-exchanging material that has adsorbed the organic quaternary ammonium ions so as to elute the ions from the material followed by an electrolyzing step of electrolyzing the eluate obtained in the eluting step to recover an aqueous solution of the organic quaternary ammonium hydroxide. The anodic liquid drawn from the electrolytic cell in the electrolyzing step may be re-circulated to the eluting step to be used as an eluent therein. By the invention, an organic quaternary ammonium hydroxide-containing waste liquid may be processed efficiently and inexpensively to give a low-COD, clean processed water, which may be directly discharged into rivers and others. If desired, the valuable substance of the organic quaternary ammonium hydroxide may be recovered efficiently and inexpensively at a high purity level.

Method of processing organic quaternary ammonium hydroxide-containing

A distillable liquid containing non-volatile impurities is freed of those impurities by boiling the liquid to form vapors of the liquid, passing the vapors through a packed column heated to a temperature such that liquid entrained in the vapors is completely vaporized and the non-volatile impurities remain in the packed column, and condensing the vapors from the column.

Method for producing high purity chemicals

This invention provides a process for producing silica from silica sol which comprises preparing an acidic silica sol applied with a hydrogen peroxide treatment from an aqueous solution of alkali silicate, purifying the acidic silica sol by using a cationic exchange resin after pH adjustment and preparing silica from the silica sol obtained by neutralizing the thus purified acidic silica sol, that is, a production process for highly pure silica capable of removing, Ti as much as possible in the same manner as impurities such as Fe and Al.

Process for producing silica of high purity

An aqueous quaternary ammonium hydroxide solution is produced by a method which is characterized by the steps of synthesizing an inorganic acid salt of quaternary ammonium by the reaction of a trialkylamine with a dialkyl carbonate and the electrolyzing the inorganic acid salt with an electrolytic cell using a cation-exchange membrane as a diaphragm thereby producing quaternary ammonium hydroxide.

Method for production of aqueous quaternary ammonium hydroxide solution

A method of manufacturing quarternary ammonium hydroxide by electrolyzing a quarternary ammonium salt in an electrolytic cell whose diaphragm is prepared from a cation exchange membrane, wherein said quarternary ammonium salt is represented by an organic acid salt expressed by the general structural formula: ##STR1## where R.sub.1 to R.sub.4 =methyl radical or ethyl radical (at least R.sub.1 to R.sub.3 denote the same radical; X represents formic acid).

Growing community of inventors

Kawasaki, Japan

Shumpei Shimizu