LAMINATE OPTICAL BODY, OPTICAL FILM, LIQUID CRYSTAL DISPLAY APPARATUS USING SAID OPTICAL FILM, AND METHOD FOR PRODUCING LAMINATE OPTICAL BODY

• US 20120003400A1
• Filed: 02/08/2010
• Published: 01/05/2012
• Est. Priority Date: 02/13/2009
• Status: Abandoned Application

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Nishimura, Akinori, Yaginuma, Hironori, Yoshimi, Hiroyuki, Takeda, Kentarou, Inagaki, Junichi, Kinoshita, Ryoji, Kitagawa, Takeharu
• Application Number:
  US13/201,580
• Publication Number:
  US 20120003400A1
• Time in Patent Office: Days
• US Class Current: 428/1.1
• CPC Class Codes: B32B 2307/412 Transparent
• CPC Class Codes: B32B 2307/418 Refractive
• CPC Class Codes: B32B 2307/42 Polarizing, birefringent, filtering
• CPC Class Codes: B32B 2307/516 mono-axially
• CPC Class Codes: B32B 2307/728 Hydrophilic
• CPC Class Codes: B32B 2307/732 Dimensional properties
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/281 comprising polyimides
• CPC Class Codes: B32B 27/288 comprising polyketones
• CPC Class Codes: B32B 27/306 comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

The present invention provides a laminate optical body, which is excellent in production efficiency, shows an extremely small axis shift and can realize a liquid crystal display apparatus showing small display unevenness. The laminate optical body of the present invention includes an elongated polarizing film having an absorption axis in a short direction thereof, and including a base material layer and a hydrophilic polymer layer to which a dichromatic substance adsorbs; and an elongated retardation film having a slow axis in a lengthwise direction thereof. The polarizing film is a laminate including the base material layer and the hydrophilic polymer layer to which a dichromatic substance adsorbs. The laminate optical body is elongated. Preferably, the hydrophilic polymer layer has a thickness of 1 μm to 10 μm.

Claims

1. An elongated laminate optical body, comprising:

an elongated polarizing film having an absorption axis in a short direction thereof, and including a base material layer and a hydrophilic polymer layer to which a dichromatic substance adsorbs; and

an elongated retardation film having a slow axis in a lengthwise direction thereof.

2. An laminate optical body according to claim 1, wherein the hydrophilic polymer layer has a thickness of 1 μ

m to 10 μ

m.

3. An laminate optical body according to claim 1, wherein the base material layer serves also as a protective layer for the hydrophilic polymer layer.

4. An laminate optical body according to claim 1, wherein the retardation film contains tilt-aligned molecules.

5. An laminate optical body according to claim 4, wherein:

the molecules in the retardation film are continuously or intermittently tilted along a thickness direction of the retardation film; and

when a tilt angle in a case where the molecules are arranged to be parallel to a plane is set to 0°

, a tilt angle on a side of the hydrophilic polymer layer is larger than a tilt angle on a side opposite to the hydrophilic polymer layer by 20°

to 70°

.

6. An laminate optical body according to claim 4, wherein the tilt-aligned molecules have an average tilt angle of 10°

to 40°

.

7. An laminate optical body according to claim 4, wherein a refractive index ellipsoid of each of the molecules in the retardation film has a relationship of nx>

ny=nz.

8. An laminate optical body according to claim 7, further comprising, on a side opposite to the hydrophilic polymer layer of the retardation film, a second elongated retardation film which has a slow axis in a short direction thereof and a refractive index ellipsoid of which has a relationship of nx>

ny>

nz.

9. An laminate optical body according to claim 8, wherein the second retardation film has an in-plane retardation value Re_2[590] of 80 to 160 nm and an Nz coefficient of 1.1 to 1.8.

10. An laminate optical body according to claim 4, wherein a refractive index ellipsoid of each of the molecules in the retardation film has a relationship of nx=ny>

nz.

11. An laminate optical body according to claim 10, wherein the retardation film has an in-plane retardation value Re_1[590] of 100 nm or less and a thickness direction retardation value Rth_1[590] of 50 nm to 200 nm.

12. An laminate optical body according to claim 10, further comprising a second elongated retardation film, wherein the second retardation film has an in-plane retardation value Re_2[590] of less than 100 nm and a thickness direction retardation value Rth_2[590] of less than 200 nm.

13. An laminate optical body according to claim 12, wherein the retardation film and the second retardation film have a total in-plane retardation value Re_1+2[590] of 10 nm or more and less than 200 nm, and a total thickness direction retardation value Rth_1+2[590] of 50 nm to 300 nm.

16. An optical film, which is obtained by cutting or punching the laminate optical body according to claim 1.

17. A liquid crystal display apparatus, comprising:

the optical film according to claim 16; and

a liquid crystal cell.

14. A method of producing an elongated laminate optical body, comprising:

applying a composition containing a hydrophilic polymer to an elongated base material to form a thin film;

stretching the thin film together with the base material;

dyeing the stretched thin film to provide an elongated polarizing film including a base material layer and a hydrophilic polymer layer; and

continuously attaching the polarizing film and an elongated retardation film to each other while aligning lengthwise directions of the films.

15. A method according to claim 14, wherein the stretching of the thin film is carried out in a short direction thereof together with the base material.