Polyimide film and process for producing the same
AssigneeKaneka Corporation
InventorsMasaru Nishinaka, Takashi Itoh
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Abstract
The polyimide film of the present invention is produced in the following manner: polyamic acid made of a combination of a specific acid anhydride constituent and a specific diamine constituent are heated under a low-pressure circumstance for heat imidation, and the obtained imide is dissolved again in a solvent to be polyimide solution, then the polyimide solution is formed to be a film. In this manner, it is possible to provide a polyimide film essentially transparent and colorless, and has sufficient toughness to prevent occurrences of a crack or a break when the film is folded and creased by hand.
Claims2
A polyimide film, which uses a soluble polyimide resin obtained by diamine constituent and acid dianhydride constituent, wherein the diamine constituent is a compound denoted by a following chemical formula (1), wherein the acid dianhydride constituent is denoted by a following chemical formula (2),
- H2N—A—R—B—R—A—NH2 (1)
- A. A SINGLE BOND OR A BIVALENT HYDROCARBON GROUP HAVING 1 TO 3 CARBON ATOMS
- OR A SINGLE BOND
- A SINGLE BOND OR A BIVALENT HYDROCARBON GROUP HAVING 1 TO 10 CARBON ATOMS
- THE Zs ARE INDEPENDENT IN THE FORMULA.
- OR DENOTES A SINGLE BOND,
- Y DENOTES,
- OR DENOTES A SINGLE BOND (n IS IN A RANGE FROM 1 TO 10)
- wherein the polyimide film has a transparency of not less than 70% with respect to light with a wavelength of 440 nm and has a tearing strength of not less than 2N/mm when it is 75 μm thick.
Dependencies are inferred from the claim text.