Optically anisotropic sheet

Patent metadata

Field	Value
Publication number	US-9442232-B2
Application number	US-201414454379-A
Country	US
Kind code	B2
Filing date	Aug 7, 2014
Priority date	Aug 9, 2013
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

Provided is an optically anisotropic sheet that gives a thin optically anisotropic film that can be transferred to a display device. The optically anisotropic sheet includes a substrate, a liquid crystal cured film, and a sticky adhesive layer in this order. The liquid crystal cured film is a film that has a thickness of 5 μm or less and is cured with a polymerizable liquid crystal compound aligned. The sticking force (F1) between the liquid crystal cured film and the sticky adhesive layer is greater than the substrate sticking force (F4).

First claim

What is claimed is:

1. An optically anisotropic sheet comprising a substrate, an alignment film, a liquid crystal cured film, and a sticky adhesive layer in this order, wherein
the alignment film is a film that has a thickness of 500 nm or less and is made of a polymer compound,
the liquid crystal cured film is a film that has a thickness of 3 μm or less and is cured with a polymerizable liquid crystal compound aligned in the direction horizontal to the plane of the substrate, and
the sticking force (F1) between the liquid crystal cured film and the sticky adhesive layer is greater than the sticking force (F2) between the substrate and the alignment film or the sticking force (F3) between the alignment film and the liquid crystal cured film,
F2 and F3 being 0.02 N/25 mm or more, F2 or F3 being less than 1 N/25 mm, wherein the liquid crystal cured film has wavelength dispersion characteristics that satisfy the following equations (1), (2), and (3):
Re (450)/ Re (550)≦1.00  (1)

1.00≦ Re (650)/ Re (550)  (2)

100< Re (550)<150  (3)

wherein Re(450), Re(550), and Re(650) represent retardation at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

2. The optically anisotropic sheet according to claim 1 , wherein the alignment film is a photoalignment film.

3. An optically anisotropic sheet comprising a substrate, a liquid crystal cured film, and a sticky adhesive layer in this order, wherein
the liquid crystal cured film is a film that has a thickness of 5 μm or less and is cured with a polymerizable liquid crystal compound aligned, and
the sticking force (F1) between the liquid crystal cured film and the sticky adhesive layer is greater than a substrate sticking force (F4), F4 being 0.02 N/25 mm or more and less than 1 N/25 mm,
wherein the liquid crystal cured film has wavelength dispersion characteristics that satisfy the following equations (1), (2), and (3):
Re (450)/ Re (550)≦1.00  (1)

1.00≦ Re (650)/ Re (550)  (2)

100< Re (550)<150  (3)

wherein Re(450), Re(550), and Re(650) represent retardation at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

4. An optically anisotropic film comprising the optically anisotropic sheet of claim 3 with the substrate removed.

5. A method for producing a display device equipped with an optically anisotropic film, comprising attaching the optically anisotropic sheet of claim 3 to a display surface of a display device via the sticky adhesive layer, and then removing the substrate of the optically anisotropic sheet.

6. An optically anisotropic sheet comprising a substrate, a liquid crystal cured film, and a sticky adhesive layer in this order, wherein
the liquid crystal cured film is a film that has a thickness of 5 μm or less and is cured with a polymerizable liquid crystal compound aligned, and
the sticking force (F1) between the liquid crystal cured film and the sticky adhesive layer is greater than a substrate sticking force (F4), F4 being 0.02 N/25 mm or more and less than 1 N/25 mm,
wherein the liquid crystal cured film has a refractive index relation expressed by the following equation (4):
nz>nx≈ny   (4)

wherein nz represents a refractive index in the thickness direction, nx represents a refractive index in the direction that gives the maximum refractive index in the plane, and ny represents a refractive index in the direction that is perpendicular to the direction of nx in the plane.

7. An optically anisotropic film comprising the optically anisotropic sheet of claim 6 with the substrate removed.

8. A circularly polarizing plate comprising a liquid crystal cured film, a sticky adhesive layer, a retardation film, and a sticky adhesive layer laminated in this order, wherein
the liquid crystal cured film is a film that has a thickness of 3 μm or less, is cured with a polymerizable liquid crystal compound aligned in the direction horizontal to the plane of the substrate, and contains a dichroic pigment.

9. The circularly polarizing plate according to claim 8 , further comprising an alignment film on a surface of the liquid crystal cured film, wherein the alignment film is a film that has a thickness of 500 nm or less and is made of a polymer compound.

10. The circularly polarizing plate according to claim 8 , wherein the sticky adhesive layer is a sticky adhesive layer formed from an active-energy-ray-curable adhesive.

11. An optically anisotropic sheet comprising a substrate, a liquid crystal cured film, and a sticky adhesive layer in this order, wherein
the liquid crystal cured film is a film that has a thickness of 5 μm or less and is cured with a polymerizable liquid crystal compound aligned, and
the sticking force (F1) between the liquid crystal cured film and the sticky adhesive layer is greater than a substrate sticking force (F4), F4 being 0.02 N/25 mm or more and less than 1 N/25 mm,
wherein the liquid crystal cured film shows a Bragg peak in X-ray diffraction measurement.

12. The optically anisotropic sheet according to claim 11 , wherein the liquid crystal cured film further contains a dichroic pigment.

13. The optically anisotropic sheet according to claim 12 , wherein the dichroic pigment contains three or more kinds of azo compounds.

14. An optically anisotropic film comprising the optically anisotropic sheet of claim 11 with the substrate removed.

15. A method for producing a display device equipped with an optically anisotropic film, comprising attaching the optically anisotropic sheet of claim 11 to a display surface of a display device via the sticky adhesive layer, and then removing the substrate of the optically anisotropic sheet.

16. An optically anisotropic sheet comprising a substrate, a liquid crystal cured film, and a sticky adhesive layer in this order, wherein
the liquid crystal cured film is a film that has a thickness of 5 m or less and is cured with a polymerizable liquid crystal compound aligned, and
the sticking force (F1) between the liquid crystal cured film and the sticky adhesive layer is greater than a substrate sticking force (F4), F4 being 0.02 N/25 mm or more and less than 1 N/25 mm,
wherein the sticky adhesive layer is a sticky adhesive layer formed from an active-energy-ray-curable adhesive.

17. A circularly polarizing plate comprising a polarizing plate, a first sticky adhesive layer, a liquid crystal cured film, and a second sticky adhesive layer laminated in this order, wherein
the liquid crystal cured film is a film that has a thickness of 3 μm or less, is cured with a polymerizable liquid crystal compound aligned in the direction horizontal to the plane of the substrate, and has wavelength dispersion characteristics that satisfy the following equations (1), (2), and (3):
Re (450)/ Re (550)≦1.00  (1)

1.00≦ Re (650)/ Re (550)  (2)

100< Re (550)<150  (3)

wherein Re(450), Re(550), and Re(650) represent retardation at wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

18. The circularly polarizing plate according to claim 17 , further comprising an alignment film between the first sticky adhesive layer and the liquid crystal cured film, wherein the alignment film is a film that has a thickness of 500 nm or less and is made of a polymer compound.

19. The circularly polarizing plate according to claim 17 , further comprising an alignment film between the liquid crystal cured film and the second sticky adhesive layer, wherein the alignment film is a film that has a thickness of 500 nm or less and is made of a polymer compound.

20. The circularl

Assignees

• Sumitomo Chemical Co

Inventors

• Hatanaka Nobuyuki
• Kobayashi Tadahiro
• Yokota Akira
• Kasai Tatsuaki

Classifications

• C09J7/0296

  Chemistry & Metallurgy · mapped topic

• G02F2202/28

  Adhesive materials or arrangements · CPC title

• C09J2203/318

  for the production of liquid crystal displays · CPC title

• G02B5/3016 Primary

  involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528) · CPC title

• C09J2201/606

  Chemistry & Metallurgy · mapped topic