Black film
AssigneeKuraray Co., Ltd.
InventorYushi Ozawa
Life of this patent
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Abstract
A black film containing a thermoplastic resin (A) that contains two or more types of dyes other than black, where a thickness T is 45 to 550 μm, a total concentration C of the dyes other than black is 0.4 to 5 mass % with respect to the thermoplastic resin (A), the total concentration C of the dyes and the thickness T satisfy the following expression (1): C×T≥210 (1) where in a L*a*b* color system measurement compliant with JIS Z 8781-4, L* (lightness) is no more than 10, an absolute value of a* is no more than 2.0, and an absolute value of b* is no more than 2.0, and a total light transmittance obtained after the black film is stretched twofold in one axial direction at a temperature higher than a glass transition temperature by 20° C. is no more than 3.0%.
Claims8
A black film comprising:
- a thermoplastic resin (A) comprising two or more types of dyes other than black, wherein
- a thickness T is 45 to 550 μm,
- the thermoplastic resin (A) is a composition containing a methacryl-based polymer (A1) in which the content of a structural unit derived from methyl methacrylate is no less than 90 mass % and the content of a structural unit derived from an acrylic acid alkyl ester having a carbon number of 6 to 12 is less than 5 mass % and an acryl-based copolymer (A2) in which the content of a structural unit derived from an acrylic acid alkyl ester having a carbon number of 6 to 12 is more than 5 mass %,
- a mass ratio of the methacryl-based polymer (A1) to the acryl-based copolymer (A2) is in a range of from 98/2 to 50/50,
- a total concentration C of the dyes other than black is 0.4 to 5 mass % with respect to the thermoplastic resin (A),
- the total concentration C of the dyes and the thickness T satisfy the following expression (1):
- C×T≥210 (1)
- wherein in a L*a*b* color system measurement compliant with JIS Z 8781-4, L* (lightness) is no more than 10, an absolute value of a* is no more than 2.0, and an absolute value of b* is no more than 2.0, and
- a total light transmittance obtained after the black film is stretched twofold in one axial direction at a temperature higher than a glass transition temperature by 20° C. is no more than 3.0%.
Dependencies are inferred from the claim text.