Liquid crystal composition, color filter and liquid crystal display device

• US 20020150698A1
• Filed: 04/10/2002
• Published: 10/17/2002
• Est. Priority Date: 04/13/2001
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kawabata, Kouya
• Granted Patent: US 6,818,261 B2
• Time in Patent Office: Days
• US Class Current: 428/1.1
• CPC Class Codes: C09K 19/38 Polymers
• CPC Class Codes: C09K 19/586 Optically active dopants; chiral dopants
• 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: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: G02B 5/201 in the form of arrays

Abstract

The present invention discloses a liquid crystal composition comprising at least a liquid crystal compound including at least one polymerizing group, a chiral agent and a polymerization initiator, and being filtered using a filter having a pore size of 1 μm or less; a liquid crystal composition comprising the components of the above-described liquid crystal composition, an air-interface orientation agent and a solvent, and having a viscosity ranging from 1 to 100 cP; a color filter produced using one of these compositions; and a liquid crystal display device employing the color filter.

Claims

1. A liquid crystal composition comprising:

a liquid crystal compound, which includes at least one polymerizing group;

a chiral agent; and

a polymerization initiator;

wherein the liquid crystal composition is filtered using a filter having a pore size of not more than 1 μ

m.

2. A liquid crystal composition according to claim 1, wherein the filtration is carried out while the liquid crystal composition is being heated.

3. A liquid crystal composition according to claim 1, wherein the chiral agent is photo-reactive.

4. A liquid crystal composition according to claim 1, wherein the liquid crystal composition has a viscosity of not more than 100 cP.

5. A liquid crystal composition according to claim 1, further comprising a surfactant.

6. A liquid crystal composition comprising:

a liquid crystal compound, which includes at least one polymerizing group;

a chiral agent;

a polymerization initiator;

an air-interface orientation agent; and

a solvent;

wherein the liquid crystal composition has a viscosity from 1 to 100 cP.

7. A liquid crystal composition according to claim 6, wherein a surface tension of the liquid crystal composition is not more than 50 mN/m.

8. A liquid crystal composition according to claim 6, wherein the chiral agent is photo-reactive.

9. A color filter produced using a liquid crystal composition comprising:

a liquid crystal compound including at least one polymerizing group;

a chiral agent; and

a polymerization initiator;

wherein the liquid crystal composition is filtered using a filter having a pore size of not more than 1 μ

m, and a rate of pixel defects in the color filter is not more than 100/m².

10. A color filter according to claim 9, wherein the pixel defects are protrusions with heights of at least 2 μ

m.

11. A color filter according to claim 9, wherein the pixel defects are white dots in a colored area having sizes of at least 30 μ

m diameter.

12. A color filter according to claim 9, wherein the pixel defects are black defects having sizes of at least 30 μ

m diameter.

13. A color filter according to claim 9, wherein the pixel defects are foreign substances having sizes of at least 3 μ

m diameter.

14. A color filter according to claim 9, wherein the color filter is produced by a method comprising the steps of:

disposing, on a substrate, a color filter forming layer, which includes the liquid crystal composition; and

irradiating ultraviolet light onto the color filter forming layer.

16. A color filter according to claim 15, wherein the color filter forming layer is formed by being coated using at least one of bar coating, spin coating and slit coating.

17. A color filter according to claim 15, wherein a thickness of the color filter forming layer from 1.5 to 4 μ

m.

15. A color filter for use in a liquid crystal display device, produced by a method comprising at least the steps of:

forming an orientation film on a substrate;

disposing, on the orientation film, a color filter comprising a liquid crystal composition; and

irradiating ultraviolet light onto the color filter forming layer;

wherein the liquid crystal composition has a viscosity from 1 to 100 cP and comprises;

a liquid crystal compound including at least one polymerizing group;

a chiral agent;

a polymerization initiator;

an air-interface orientation agent; and

a solvent.

18. A liquid crystal display device comprising:

a pair of substrates, at least one of which transmits light;

a color filter, a liquid crystal layer and a liquid crystal driving electrode disposed between the substrates;

wherein the color filter is produced using a liquid crystal composition comprising a liquid crystal compound including at least one polymerizing group;

a chiral agent; and

a polymerization initiator, the liquid crystal composition being filtered using a filter having a pore size of not more than 1 μ

m, and a rate of pixel defects in the color filter is not more than 100/m².

19. A liquid crystal display device comprising a color filter produced by a method comprising the steps of:

forming an orientation film on a substrate;

disposing, on the orientation film, a color filter forming layer comprising a liquid crystal composition; and

irradiating ultraviolet light onto the color filter forming layer;

wherein the liquid crystal composition includes at least one polymerizing group;

a chiral agent;

a polymerization initiator;

an air-interface orientation agent; and

a solvent, and the liquid crystal composition has a viscosity from 1 to 100 cP.