Cellulose Acylate Film, Method for Producing Cellulose Acylate Film, Polarizing Plate and Liquid Crystal Display Device
AssigneeFUJIFILM Corporation
InventorsNobutaka Fukagawa, Tadashi Omatsu, Yutaka Nozoe, Takuya Inoue, Naoki Hayashi
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Abstract
A method for producing a cellulose acylate film containing an additive comprising an aliphatic compound, the method contains a process of thermal shrinkage treatment at an atmospheric temperature higher than the glass transition temperature (Tg) in the state where at least one of the transverse direction and the machine direction of the film is free, and a cellulose acylate film obtained by the above method.
Claims15
A cellulose acylate film, which has an in-plane retardation Re and a retardation in a thickness direction Rth at 25° C., 60% RH satisfying relationships of equations (A) and (B),
- wherein an amount of an elution of an additive per 100 g of the cellulose acylate film is 100 mg or less when the cellulose acylate film is immersed in 1 liter of 1.5 mol/liter of sodium hydroxide solution at 55° C. for 10 minutes:
- 0 nm≦Re(λ)≦10 nm (A)
- −25 nm≦Rth(λ)≦25 nm (B)
- wherein Re (λ) and Rth (λ) represent Re and Rth measured at a wavelength of λ nm respectively;
- and
- λ is from 400 to 700 nm.
A cellulose acylate film, which has an in-plane retardation Re and a retardation in a thickness direction Rth at 25° C., 60% RH satisfying relationships of equations (A) and (B),
- wherein variations in the retardations Re and Rth at 25° C., 60% RH before and after immersion of the cellulose acylate film in 1.5 mol/liter of sodium hydroxide solution at 55° C. for 10 minutes satisfy relationships of equations (C) and (D):
- 0 nm≦Re(590)≦10 nm (A)
- −25 nm≦Rth(590)≦25 nm (B)
- 2 nm≦[(Re before immersion treatment)−(Re after immersion treatment)]≦2 nm (C)
- −3 nm≦[(Rth before immersion treatment)−(Rth after immersion treatment)]≦3 nm (D)
- wherein in the equations (A) and (B), Re (590) and Rth (590) represent Re and Rth measured at a wavelength of 590 nm, respectively;
- and
- in equations (C) and (D), Re and Rth are values at a wavelength of 590 nm.
A cellulose acylate film, which has an in-plane retardation Re and a retardation in a thickness direction Rth at 25° C., 60% RH satisfying relationships of equations (A) and (B),
- wherein a residual rate of an additive in the cellulose acylate film after aging at 140° C. for 10 hours is 98% or more:
- 0 nm≦Re(λ)≦10 nm (A)
- −25 nm≦Rth(λ)≦25 nm (B)
- wherein Re (λ) and Rth (λ) represent Re and Rth measured at a wavelength of λ nm, respectively;
- and
- λ is from 400 to 700 nm.
A cellulose acylate film, which has an in-plane retardation Re and a retardation in a thickness direction Rth at 25° C., 60% RH satisfying relationships of equations (A) and (B),
- wherein orientation coefficients of a main chain and a carbonyl group in the cellulose acylate film satisfy relationships of equations (E) to (H):
- 0 nm≦Re(λ)≦10 nm (A)
- −25 nm≦Rth(λ)≦25 nm (B)
- 0.02≦an orientation coefficient of a main chain in a thickness direction≦0.20 (E)
- −0.04≦an orientation coefficient of a main chain in an in-plane direction≦0.10 (F)
- −0.10≦an orientation coefficient of a carbonyl group in a thickness direction≦−0.02 (G)
- −0.10≦an orientation coefficient of a carbonyl group in an in-plane direction≦0.02 (H)
- wherein in equations (A) and (B), Re (λ) and Rth (λ) represent Re and Rth measured at a wavelength of λ nm, respectively;
- and
- λ is from 400 to 700 nm.
A method for producing a cellulose acylate film comprising:
- a process of subjecting a cellulose acylate film that comprises an additive comprising an aliphatic compound to thermal shrinkage treatment at an atmospheric temperature higher than a glass transition temperature Tg in a state where at least one of a transverse direction and a machine direction of the cellulose acylate film is free.
Dependencies are inferred from the claim text.