Abstract: A method of applying a mold-releasing agent to the molding surfaces of a mold after cleaning the surface. This method involves inserting a mold-releasing sheet between said molding surfaces of a mold coating the molding surfaces with the mold releasing agent by heating and pressing the mold-releasing sheet to cure it, and removing the cured sheet from the molding surfaces of the mold. This mold-releasing sheet is composed of (i) uncured rubber, (ii) a curing agent, and (iii) a mold releasing agent. The uncured rubber can be selected from a group consisting of chloroprene rubber, butadiene rubber, nitrile rubber, ethylene-propylene terpolymer rubber, styrene-butadiene rubber, polyisoprene rubber, butyl rubber, silicone rubber, and fluoridated rubber.

Abstract: A mold-cleaning composition and sheet comprising an uncured rubber composition comprising an uncured rubber and a curing agent, and at least one removal aid selected from imidazoles and imidazolines, and a method for cleaning a mold using the mold-cleaning sheet, are disclosed. The mold-cleaining sheet is suitably used to clean molding surfaces of a mold or to remove contaminants such as burr formed at peripheries thereof in the continuous production of semiconductor devices by transfer molding.