Laqua

Example 1

(Preparation of Composition for Surface Treatment A-1)

0.5 parts by mass of an aqueous maleic acid solution at a concentration of 30% by mass (0.18 parts by mass of maleic acid) as an organic acid, 0.05 parts by mass of sodium polystyrene sulfonate (manufactured by Tosoh Organic Chemical Co., Ltd., Product name: Poly NaSS (registered trademark) PS-1, weight average molecular weight: 20,000, pKa value: 1.0) (0.01 parts by mass of sodium polystyrene sulfonate) as a polymer compound, 0.02 parts by mass of sodium polyoxyethylene (POE) alkyl ether phosphate (n=1) (C₁₈H₃₇O(POE))₂—PO₂Na) as an anionic surfactant, and an amount to be 100 parts by mass in total of water (deionized water) were mixed, thereby preparing composition for surface treatment A-1. When the pH of composition for surface treatment A-1 (liquid temperature: 25° C.) was confirmed by a pH meter (manufactured by HORIBA, Ltd., product name: LAQUA (registered trademark)), pH was 2.1.

Example 1

As an abrasive grain, cation-modified colloidal silica in which an amino group is immobilized on the surface (average primary particle size of 35 nm, average secondary particle size of 70 nm, average association degree of 2.0) was added to water so as to have a concentration of 0.5% by mass with respect to 100% by mass of the total mass of the polishing composition. In addition, 1,2,3,4-butanetetracarboxylic acid was added to the mixture of the abrasive grain and water in such an amount that a pH of the polishing composition was 4.5. Thereafter, the mixture was stirred and mixed at room temperature (25° C.) for 30 minutes to prepare a polishing composition.

The average primary particle size of the abrasive grains was calculated from the specific surface area of the abrasive grains measured by a BET method using “Flow Sorb II 2300” manufactured by Micromeritics and the density of the abrasive grains. Further, the average secondary particle size of the abrasive grains was measured by a dynamic light scattering particle diameter and particle size distribution device UPA-UTI 151 manufactured by Nikkiso Co., Ltd. Furthermore, the pH of the polishing composition (liquid temperature: 25° C.) was confirmed with a pH meter (model: LAQUA manufactured by Horiba, Ltd.).

Example 2

A composition for surface treatment A-2 was prepared by mixing 0.5 parts by mass of an aqueous solution of maleic acid (0.18 parts by mass of maleic acid) with a concentration of 30% by mass as an organic acid, 0.066 parts by mass of sodium polystyrenesulfonate (Product name: POLINAS® PS-1 manufactured by Tosoh Organic Chemical Co., Ltd.; weight average molecular weight of 10,000 to 30,000), and 0.1 parts by mass of ethylenediamine tetra(methylenephosphonic acid) 5-Na salt (DEQUEST® 2046), with water (deionized water) so that the total amount of the composition was 100 parts by mass. The pH confirmed by a pH meter (Product name: LAQUA® manufactured by HORIBA, Ltd.) was 2 for the composition for surface treatment A-2 (liquid temperature: 25° C.).

Example 3

Each composition for surface treatment was prepared in the same manner as in Example 2 except that each component was changed to the kind shown in Table 1 below. In addition, “-” in Table indicates that the corresponding component was not used. Further, the pH of each composition for surface treatment is also shown in Table 1 below.