Patent ID: 7918941

Claim:
A cleaning process for a substrate for recording media, a substrate for photomask, or a substrate for flat panel display, a surface of which at least comprises a metallic or glassy substrate moiety, with a cleaning agent composition, comprising the following step (a) or (b): (a) immersing the substrate for recording media, the substrate for photomask, or the substrate for flat panel display in the cleaning agent composition at a temperature of from 20° to 100° C., an immersion time of from 10 seconds to 30 minutes, and a frequency of ultrasonic waves of from 20 to 200 kHz; or (b) ejecting the cleaning agent composition, thereby cleaning a surface of the substrate for recording media, the substrate for photomask, or the substrate for flat panel display, while contacting a cleaning brush with the surface in the presence of the ejected cleaning agent composition, wherein the cleaning agent composition is alkaline and is prepared by blending Component A and Component B, wherein Component A is a copolymer compound satisfying at least the following (i) to (iii): (i) a constituting unit A1 derived from acrylic acid is contained in an amount of 20% by mol or more of the entire constituting units, (ii) the constituting unit A1 derived from acrylic acid and a constituting A2 derived from 2-acrylamide-2-methylpropanesulfonic acid are contained in a total amount of 90% by mol or more of the entire constituting units, and (iii) the constituting unit A1 and the constituting unit A2 of the entire constituting units are in a content ratio [constituting unit A1 (% by mol)/constituting unit A2 (% by mol)] of from 91/9 to 95/5; wherein Component B is C 12-14 O(EO) 5 (PO) 1.5 (EO) 5 H; and wherein Component A and the Component B are contained in a total amount of from 0.001 to 5% by weight.