| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous cleaning agent composition for substrates for perpendicular magnetic recording hard disk having a high cleaning capability, a cleaning method performed by using the same, and a method for manufacturing a perpendicular magnetic recording hard disk. SOLUTION: The aqueous cleaning agent composition for substrates for perpendicular magnetic recording hard disk having an Ni-P-containing layer contains one surfactant or more selected from the group consisting of surfactants represented by formulae (1) and (2)-(6)(unillustrated), and having a pH of not more than 5 at 25°C. In formula (1), R<SP>1</SP>represents an alkyl group having 10-16 carbon atoms, and X represents a halogen atom. COPYRIGHT: (C)2009,JPO&INPIT |
