01-08-2013 дата публикации
Номер: US20130196134A1
The present disclosure is directed to a base film having a thickness from 8 to 152 microns, a 60 degree gloss value from 2 to 35, an optical density greater than or equal to 2 and a dielectric strength greater than 1400 V/mil. The base film comprises a chemically converted (partially or wholly aromatic) polyimide in an amount from 71 to 96 weight percent of the base film. The base film further comprises a pigment and a matting agent. The matting agent is present in an amount from 1.6 to 10 weight percent of the base film, has a median particle size from 1.3 to 10 microns, and has a density from 2 to 4.5 g/cc. The pigment is present in an amount from 2 to 9 weight percent of the base film. The present disclosure is also directed to coverlay films comprising the base film in combination with an adhesive layer. 1. A base film comprising: i. at least 50 mole percent of an aromatic dianhydride, based upon a total dianhydride content of the polyimide, and', 'ii. at least 50 mole percent of an aromatic diamine based upon a total diamine content of the polyimide;, 'A. a chemically converted polyimide in an amount from 40 to 90 weight percent of the base film, the chemically converted polyimide being derived from 'wherein the thickness of the base film is from 8 to 152 microns.', 'B. a filler, excluding low conductivity carbon black and pigments, in an amount from 10 to 60 wt % of the base film; and'}2. The base film in accordance with wherein the chemically converted polyimide is made by the step of mixing a polyamic acid solution with a catalyst or dehydrating agent capable of converting a polyamic acid to a polyimide.3. The base film in accordance with wherein: pyromellitic dianhydride,', '3,3′,4,4′-biphenyl tetracarboxylic dianhydride,', '3,3′,4,4′-benzophenone tetracarboxylic dianhydride;', '4,4′-oxydiphthalic anhydride,', '3,3′,4,4′-diphenyl sulfone tetracarboxylic dianhydride,', '2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane,', 'Bisphenol A dianhydride, and', ' ...
Подробнее
