Matte finish polyimide films and methods relating thereto
View Patent ↗The present disclosure is directed to a base film having a chemically converted polyimide, a particulate polyimide matting agent and a low conductivity carbon black. The particulate polyimide matting agent is present in an amount from 1.6 to 20 weight percent of the base film.
1. A base film comprising:
A. a chemically converted polyimide present in an amount from 75 to 96 weight percent of the base film, the chemically converted polyimide being derived from:
a. 100 mole percent pyromellitic dianhydride, based upon a total dianhydride content of the chemically converted polyimide, and
b. 100 mole percent 4,4′-oxydianiline based upon a total diamine content of the chemically converted polyimide;
B. a low conductivity carbon black present in an amount from 2 to 9 weight percent of the base film; and
C. a particulate polyimide matting agent present in an amount from 1.6 to 9 weight percent of the base film and having a median particle size from 1.3 to 10 microns.
2. The base film in accordance with claim 1 wherein the particulate polyimide matting agent has a refractive index from 1.65 to 1.85.
3. The base film in accordance with claim 1 , wherein the particulate polyimide matting agent and the chemically converted polyimide have a refractive index within and including 0.1 unit of each other.
4. The base film in accordance with claim 1 wherein the particulate polyimide matting agent is derived from at least 50 mole percent of an aromatic dianhydride and at least 50 mole percent of an aromatic diamine.
5. A multilayer film comprising the base film of claim 1 and an adhesive layer.
6. The multilayer film in accordance with claim 5 , wherein the adhesive layer is an epoxy resin selected from the group consisting of: bisphenol A type epoxy resin, cresol novolac type epoxy resin, phosphorus containing epoxy resin, and mixtures thereof.
7. The base film in accordance with claim 1 additionally comprising a dye present in an amount from 0.1 to 10 weight percent.
8. A base film comprising:
A. a chemically converted polyimide present in an amount from 75 to 96 weight percent of the base film, the chemically converted polyimide being derived from:
a. 100 mole percent pyromellitic dianhydride, based upon a total dianhydride content of the chemically converted polyimide, and
b. 100 mole percent 4,4′-oxydianiline based upon a total diamine content of the chemically converted polyimide;
B. a low conductivity carbon black present in an amount from 2 to 9 weight percent of the base film; and
C. a particulate polyimide matting agent present in an amount from 1.6 to 9 weight percent of the base film, having a median particle size from 1.3 to 10 microns and having a refractive index from 1.65 to 1.85; and
wherein the base film has a 60 degree gloss value from 2 to 35 on both sides.
9. A base film comprising:
A. a chemically converted polyimide present in an amount from 75 to 96 weight percent of the base film, the chemically converted polyimide being derived from:
a. 100 mole percent pyromellitic dianhydride, based upon a total dianhydride content of the chemically converted polyimide, and
b. 100 mole percent 4,4′-oxydianiline based upon a total diamine content of the chemically converted polyimide;
B. a low conductivity carbon black present in an amount from 2 to 9 weight percent of the base film; and
C. a particulate polyimide matting agent present in an amount from 1.6 to 9 weight percent of the base film and having a median particle size from 1.3 to 10 microns, the particulate polyimide matting agent and the chemically converted polyimide have a refractive index within and including 0.1 unit of each other; and wherein the base film has a 60 degree gloss value from 2 to 35 on both sides.