| abstract |
The present invention provides a carboxylic acid derivative comprising at least one selected from the group consisting of a phthalic acid compound, an isophthalic acid compound, an alkyldicarboxylic acid compound represented by the following general formula (I), and salts and acid anhydrides thereof, and a metal type A polishing agent for polishing a layer containing water and a cobalt element containing water and having a pH of 4.0 or less is provided. In general formula (I), R represents a C4-C10 alkylene group. HOOC-R-COOH... (I) |