Patent ID: 11945911
Assignee: MITSUI CHEMICALS, INC.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C  B | IPC C

Claim 0:
1. A polymer film comprising a polyimide that is a polymer of a diamine component and a tetracarboxylic dianhydride component, wherein
the diamine component includes t-diaminocyclohexane,
the tetracarboxylic dianhydride component includes
a tetracarboxylic dianhydride A represented by general formula (a) or general formula (b):, wherein, in general formulae (a) and (b), R1, R2, R3, and R4 each independently represent an alkyl group having 1 to 4 carbon atoms, and a, b, c, and d each represent an integer of 0 to 3 (provided that a+b is 3 or less, and c+d is 3 or less),
a tetracarboxylic dianhydride B represented by general formula (c) or general formula (d):, wherein, in general formulae (c) and (d), R5, R6, R7, and R8 each independently represent an alkyl group having 1 to 4 carbon atoms, and e, f, g, and h each represent an integer of 0 to 3 (provided that e+f is 3 or less, and g+h is 3 or less), and
a tetracarboxylic dianhydride C represented by general formula (e):, wherein, in general formula (e), R9 and R10 each independently represent an alkyl group having 1 to 4 carbon atoms, and m and n each represent an integer of 0 to 3 (provided that m+n is 3 or less);
t-diaminocyclohexane is included in an amount of 90 mol % to 100 mol % based on the total amount of the diamine component; and
the polymer film satisfies all requirements (i) to (vi):
(i) to have an average coefficient of thermal expansion in a range of 100° C. to 200° C. of 35 ppm/K or less;
(ii) to have a thickness-direction retardation whose absolute value is 200 nm or less per 10 μm thickness;
(iii) to have a glass transition temperature of 340° C. or higher;
(iv) to have a total light transmittance of 85% or more;
(v) to have a b* value in the L*a*b* color system of 5 or less; and
(vi) to have a tensile elongation of 10% or more.