Cholesteric liquid crystal additives

• US 7,153,549 B2
• Filed: 02/09/2006
• Issued: 12/26/2006
• Est. Priority Date: 02/24/2003
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Pokorny, Richard J., Spawn, Terence D., Radcliffe, Marc D.
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US11/351,055
• Publication Number:
  US 20060124898A1
• Time in Patent Office: 320 Days
• Field of Search: 252/299.7, 252/299.01, 252/299.5, 252/299.64, 252/299.65, 252/299.67, 428/1.1, 428/1.31, 349/115
• US Class Current: 428/1.1
• CPC Class Codes: C09K 19/2007 the chain containing -COO- or -OCO- groups
• CPC Class Codes: C09K 19/54 Additives having no specific mesophase characterised by their chemical composition
• CPC Class Codes: C09K 19/56 Aligning agents
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate
• 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: C09K 2323/031 Polarizer or dye

Abstract

The invention provides a cholesteric liquid crystal composition that includes at least one cholesteric liquid crystal precursor, and at least one non-liquid crystalline additive that is a non-liquid crystalline compound of formula I

The invention also provides cholesteric liquid crystal films and optical bodies formed from cholesteric liquid crystal compositions of the invention. The invention further provides an optical display that includes a display medium, and a reflective polarizer including a cholesteric liquid crystal composition in accordance with the invention.

Claims

1. A cholesteric liquid crystal composition comprising:

at least one cholesteric liquid crystal precursor; and

at least one non-liquid crystalline additive of formula I

2. The composition according to claim 1, wherein the cholesteric liquid crystal composition has a transmission that is not greater than that of the cholesteric liquid crystal composition without the additive.

3. The composition according to claim 1, wherein a cholesteric liquid crystal film formed from the cholesteric liquid crystal composition has an extinction that is less than that of a film formed from the cholesteric liquid crystal composition without the additive.

4. The composition according to claim 1, wherein the film formed from the cholesteric liquid crystal composition has an extinction that is at least 5% less than the cholesteric liquid crystal composition without the additive.

5. The composition according to claim 1, wherein the at least one cholesteric liquid crystal precursor comprises a compound of formula II

6. The composition according to claim 5, wherein at least Q is the same in both formula I, and II.

7. The composition according to claim 5, wherein Q, U, V, g, and h are the same in both formula I, and II;

and b and c are both 0 in formula I.

8. The composition according to claim 5, wherein at least Q, U, V, X, N, Z, f, g, and h are the same in both formula I and II;

and b is 0 and c is 1 in formula I.

9. The composition according to claim 5, wherein at least Q, U, V, X, N, Z, W, M, Y, e, f, g, and h are the same in both formula I and II and b and c are 1 in formula I.

10. The composition according to claim 5, wherein the cholesteric liquid crystal precursor is cyanobiphenyl benzoate ethyl acrylate and the additive is 4′

-cyano-1,1′

-biphenyl-4-yl 4-methoxybenzoate, 4′

-cyano-1,1′

-biphenyl-4-yl 4-ethoxybenzoate, 4′

-cyano-1,1′

-biphenyl-4-yl 4-propoxybenzoate, 4′

-cyano-1,1′

-biphenyl-4-yl 4-butoxybenzoate, or a combination thereof.

11. The composition according to claim 5, wherein the amount of the additive of formula I is about 1 to 35% by weight of the total solids content of the composition.

12. The composition according to claim 5, wherein the amount of the additive of formula I is about 10 to 20% by weight of the total solids content of the composition.

13. The composition according to claim 5, wherein the amount of the additive of formula I is about 15% by weight of the total solids content of the composition.

14. The cholesteric liquid crystal composition according to claim 1 further comprising a solvent.

15. The cholesteric liquid crystal composition according to claim 1 further comprising at least one compound that functions as an initiator, a terminator, a curing agent, a crosslinker, an antiozonant, an antioxidant, a plasticizer, a stabilizer, a light absorbing dye, or a pigment.

16. A cholesteric liquid crystal layer formed from a cholesteric liquid crystal composition in accordance with claim 1.

17. An optical body comprising a cholesteric liquid crystal layer in accordance with claim 16.

18. An optical display comprising:

a display medium; and

a reflective polarizer comprising a cholesteric liquid crystal composition according to claim 1.

19. An optical display comprising:

a display medium; and

a reflective polarizer comprising a cholesteric liquid crystal composition according to claim 16.

20. The optical display according to claim 19, wherein at least Q is the same in both formula I, and II.

21. The optical display according to claim 19, wherein Q, U, V, g, and h are the same in both formula I, and II;

and b and c are both 0 in formula I.

22. The optical display according to claim 19, wherein at least Q, U, V, X, N, Z, f, g, and h are the same in both formula I and II;

and b is 0 and c is 1 in formula I.

23. The optical display according to claim 19, wherein at least Q, U, V, X, N, Z, W, M, Y, e, f, g, and h are the same in both formula I and II and b and c are 1 in formula I.