Base film for photographic film
AssigneeTeijin Limited
InventorsHiroshi Okamoto, Kohtaro Katoh, Hiroshi Tomita, Kenji Suzuki, Kazuyoshi Saitoh
Life of this patent
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Abstract
A base film for a photographic film, wherein (a) the refractive index (nz) in the thickness direction is at least 1.498, (b) the haze value is 2.0% or less, (c) the base film has one direction in which the tan.delta. value, at 80.degree. C. by tensile viscoelasticity at 0.05 Hz, is 0.09 or less, (d) the anti-curling ratio at 70.degree. C. is at least 45%, (e) the thickness is in the range of from 40 to 120 .mu.m, and (f) the base film is formed from polyethylene-2,6-naphthalendedicarboxylate as a substantial raw material. This base film has various performances such as anti-curling properties, transparency and lubricity, suitable for use in a photographic film.
Claims24
A base film for a photographic film wherein
- (a) the refractive index (nz) in the thickness direction is at least 1,498,
- (b) the haze value is 2.0% or less,
- (c) the base film has one direction in which the tan.delta. value, at 80.degree. C. by tensile viscoelasticity at 0.05 Hz, is less than 0.085,
- (d) the anti-curling ratio at 70.degree. C. is at least 45%,
- (e) the thickness is in the range of from 40 to 120 .mu.m, and
- (f) the base film is formed form polyethylene-2,6-napthalenedicarboxylate as a raw material.
A base film for a photographic film, wherein
- (a) the refractive index (nz) in the thickness direction is at least 1.498,
- (b) the haze value is 2.0% or less,
- (c) the base film has one direction in which the tan.delta. value, at 80.degree. C. by tensile viscoelasticity at 0.05 Hz, is 0.09 or less,
- (d) the anti-curling ratio at 70.degree. C. is at least 45%,
- (e) the thickness is in the range of from 40 to 120 .mu.m, and
- (f) the base film is formed of a laminated film formed of a first layer of polyethylene-2,6-naphthalenedicarboxylate containing less than 0.003% by weight of inert fine particles having an average particle diameter of 0.01 to 1.15 .mu.m and a second layer of polyethylene-2,6-naphthalenedicarboxylate containing 0.003 to 0.5% by weight of inert fine particles having a average particle diameter of 0.01 to 1.15 .mu.m, the second layer having a thickness of 10 .mu.m or less.
A photographic film, comprising a photographic emulsion layer and a base film wherein in the base film
- (a) the refractive index (nz) in the thickness direction is 1.498 to 1.510,
- (b) the haze value is 1.5 % or less,
- (c) the base film has one direction in which the tan.delta. value, at 80.degree. C. by tensile viscoelasticity at 0.05 Hz, is 0.06 to 0.08,
- (d) the anti-curling ratio at 70.degree. C. is at least 50%,
- (e) the thickness is in the range of from 40 to 120 .mu.m, and
- (f) the base film contains at least 97 mol % of polyethylene-2,6-naphthalenedicarboxylate,
- and wherein
- the base film has two directions crossing each other at right angles in which the base film has Young's moduli of 400 to 750 kg/mm.sup.2 in each direction and the Young's modulus difference between the two directions is 150 kg/mm.sup.2 or less, and
- the base film has a net ANSI curl value of 10 or less when the base film is heat-treated and core set on a core having an outer diameter of 3 inches at 49.degree. C. at 50% RH for 24 hours.
Dependencies are inferred from the claim text.