Transparent polyimide film
AssigneeTaimide Tech. Inc.
InventorsYi-Hsueh Ho, Yi-Ting Liu
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Abstract
A transparent polyimide film, prepared from a copolymerized polyamide acid according to a chemical cyclization method, is provided. The copolymerized polyamide acid requires at least a semi-aromatic polyamide acid, and the semi-aromatic polyamide acid is formed by reacting cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) and 2,2′-bis(trifluoromethyl)diaminodiphenyl (TFMB). The molar number of dianhydrides of the semi-aromatic polyamide acid is more than 20% of the total molar number of anhydrides of the copolymerized polyamide acid, so that the transparent polyimide film has a light transmittance greater than 80%, a chroma b* less than 5, and a CTE less than 35 ppm/° C.
Claims3
A transparent polyimide film prepared from a copolymerized polyamide acid by a chemical cyclization method, wherein the copolymerized polyamide acid includes a semi-aromatic polyamide acid, and the semi-aromatic polyamide acid is formed by reacting cyclobutane-1,2,3,4-tetracarboxylic dianhydride (CBDA) and 2,2′-bis(trifluoromethyl)diaminodiphenyl (TFMB), wherein the molar number of dianhydrides of the semi-aromatic polyamide acid is more than 20% of the total molar number of anhydrides of the copolymerized polyamide acid, so that the transparent polyimide film has a thickness of 50-80 μm, a chroma b* less than 5, and a CTE less than 35 ppm/° C.;
- wherein the copolymerized polyamide acid further includes 4,4-hexafluoro isopropyl phthalic anhydride (6FDA) with a molar number of more than 50% of the total molar number of anhydrides of the copolymerized polyamide acid.
Dependencies are inferred from the claim text.