| 摘要 |
PROBLEM TO BE SOLVED: To reduce the depositing amount of oligomer as well as the migration of silicone, and improve transparency by a method wherein the difference of turbidity of a releasing film after and before the heat treatment of a parting layer, provided on one side of a polyethylene terephthalate film and having a specified remaining adhesion rate, is specified. SOLUTION: The remaining adhesion rate of a parting layer, constituting a releasing film consisting of polyethylene terephthalate, is specified to be 80% or more, the difference of turbidity between that of a releasing film after the heat treatment for 30 min at 170 deg.C and that of the parting film at a normal temperature before heat treatment is specified to be 3 or less and the light beam transmittance (%) of the releasing film in the wavelength of 550 nm is specified to be 70 or more. The parting layer, constituting the releasing film, is preferable to contain a curing type silicone resin from the view point of improving the mold releasing property of the same. Either one curing reaction of addition type, condensation type, ultraviolet ray curing type, electron beam curing type and non-solvent type can be employed as the curing type silicone resin. |
