| 摘要 |
PCT No. PCT/US85/02339 Sec. 371 Date Jul. 25, 1986 Sec. 102(e) Date Jul. 25, 1986 PCT Filed Nov. 22, 1985 PCT Pub. No. WO86/03145 PCT Pub. Date Jun. 5, 1986.A composition and method for removing conforming coatings such as polyurethane or epoxy from printed circuit boards is disclosed. The composition comprises separate base and activator components which are mixed to form the coating remover. The base component comprises methylene chloride or toluene, or a mixture thereof, preferably together with a thickening agent. In general, the activator component comprises (a) from about 75 to about 85 parts methylene chloride or toluene, or a mixture thereof, (b) about 7 to about 25 parts lower alkyl alcohol, and (c) about 2 to about 8 parts acetone or methylethylketone. For epoxy conformal coatings, the activator component preferably comprises 85 parts of (a): about 7 to about 15 parts of (b); and about 2 to about 6 parts of (c). The activator component for removing polyurethane conformal coatings preferably comprises 75 parts of (a), about 15 to about 25 parts of (b); about 2 to about 8 parts of (c). The base component is usually mixed with the activator component in a ratio of from 1:1 to 10:1, depending on the thickness of the coating to be removed. The composition is used by combining the base component with the activator component, treating a conformal coating on a printed circuit board by applying the coating remover thereto, and removing the treated conformal coating. Ultraviolet light accelerates the reaction between the conformal coating and the composition of the present invention.
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