Abstract: A release process film which comprises a base material film and an adhesive layer disposed on one face of the base material film and is used by attaching to a flexible printed circuit board, wherein the adhesive layer is formed with an adhesive comprising an acrylate-based copolymer at least comprising 40 to 99% by mass of a butyl acrylate unit and 1 to 20% by mass of a monomer unit having a crosslinking functional group and a crosslinking agent and the film has specific properties. The film can effectively suppress contamination of the surface of a printed circuit board with solvents and foreign substances and formation of flaws on the surface in the process using the flexible printed circuit board for producing electronic and electric instruments.

Abstract: A release process film which comprises a base material film and an adhesive layer disposed on one face of the base material film and is used by attaching to a flexible printed circuit board, wherein the adhesive layer is formed with an adhesive comprising an acrylate-based copolymer at least comprising 40 to 99% by mass of a butyl acrylate unit and 1 to 20% by mass of a monomer unit having a crosslinking functional group and a crosslinking agent and the film has specific properties. The film can effectively suppress contamination of the surface of a printed circuit board with solvents and foreign substances and formation of flaws on the surface in the process using the flexible printed circuit board for producing electronic and electric instruments.