Liquid crystal composition, patterned phase delay film and preparation method thereof, and display device

Patent metadata

Field	Value
Publication number	US-2016355733-A1
Application number	US-201514894798-A
Country	US
Kind code	A1
Filing date	Jun 18, 2015
Priority date	Dec 15, 2014
Publication date	Dec 8, 2016
Grant date	—

Abstract

A liquid crystal composition is disclosed, which comprises a photo-polymerizable liquid crystal mixture and a heat-polymerizable liquid crystal mixture, and the two mixtures have opposite rotatory directions. A patterned phase delay film prepared from the liquid crystal mixtures and preparation method thereof, as well as a display device comprising the phase delay film are also disclosed. The preparation of the patterned phase-delay film can be implemented by a two-step polymerization process including UV-polymerization and photo-polymerization. The process is simple and the costs are low.

First claim

1 . A liquid crystal composition comprising a photo-polymerizable liquid crystal mixture and a heat-polymerizable liquid crystal mixture, wherein the photo-polymerizable liquid crystal mixture and heat-polymerizable liquid crystal mixture have opposite rotatory directions.

2 . The liquid crystal composition according to claim 1 wherein a mass ratio of the photo-polymerizable liquid crystal mixture to the heat-polymerizable liquid crystal mixture is 1:(0.4-3).

3 . The liquid crystal composition according to claim 1 wherein the photo-polymerizable liquid crystal mixture comprises a small molecule nematic liquid crystal, a photo-polymerizable monomer, a UV-absorbing dye, a chiral additive and a photoinitiator; or
wherein the heat-polymerizable liquid crystal mixture comprises a small molecule nematic liquid crystal, a heat-polymerizable monomer, a curing agent and a chiral additive.

4 . The liquid crystal composition according to claim 3 wherein the photo-polymerizable liquid crystal mixture comprises, by mass percentage, 28-69.5% of small molecule nematic liquid crystal, 15-40% of photo-polymerizable monomer, 2-15% of UV-absorbing dye, 0-25% of chiral additive and 0.5-5% of photoinitiator.

5 . The liquid crystal composition according to claim 4 wherein the photo-polymerizable monomer includes any one of the following substances:

6 . The liquid crystal composition according to claim 4 wherein the UV-absorbing dye includes:

7 . The liquid crystal composition according to claim 4 wherein the photoinitiator includes:

8 . (canceled)

9 . The liquid crystal composition according to claim 3 wherein the heat-polymerizable liquid crystal mixture comprises, by mass percentage, 35-73% of small molecule nematic liquid crystal, 10-20% of heat-polymerizable monomer, 12-20% of curing agent and 5-25% of chiral additive.

10 . The liquid crystal composition according to claim 3 wherein the heat-polymerizable monomer includes:
a bisphenol F epoxy resin which has the following molecular formula:

or
a polyethylene glycol bisglycidyl ether which has the following molecular formula:

11 . The liquid crystal composition according to claim 3 wherein the curing agent includes:
1,8-diamino-3,6-dioxaoctane which has the following molecular formula:

or
4,4′-diaminodicyclohexylmethane which has the following molecular formula:

12 . The liquid crystal composition according to claim 3 wherein the chiral additive includes any one of the following substances:

13 . A patterned phase delay film, wherein the patterned phase delay film is prepared from the liquid crystal composition according to claim 1 .

14 . A method for preparing a patterned phase delay film comprising the following steps of:
injecting the liquid crystal composition according to claim 1 into a liquid crystal cell; irradiating the liquid crystal cell partially covered with a photo mask with UV light to complete UV-polymerization; and heating the liquid crystal cell to complete heat-polymerization.

15 . The method according to claim 14 wherein a condition for the UV-polymerization is UV light intensity being 0.001-100 mW/cm 2 and irradiation time being 5-240 min.

16 . The method according to claim 14 wherein a condition for the heat-polymerization is temperature being 30-120° C. and heating time being 20-60 min.

17 . A display device comprising the patterned phase-delay film according to claim 13 .

18 . The patterned phase delay film according to claim 13 wherein a mass ratio of the photo-polymerizable liquid crystal mixture to the heat-polymerizable liquid crystal mixture is 1:(0.4-3) in the liquid crystal composition.

19 . The patterned phase delay film according to claim 18 wherein the photo-polymerizable liquid crystal mixture comprises a small molecule nematic liquid crystal, a photo-polymerizable monomer, a UV-absorbing dye, a chiral additive and a photoinitiator; or
wherein the heat-polymerizable liquid crystal mixture comprises a small molecule nematic liquid crystal, a heat-polymerizable monomer, a curing agent and a chiral additive.

20 . The patterned phase delay film according to claim 19 wherein the photo-polymerizable liquid crystal mixture comprises, by mass percentage, 28-69.5% of small molecule nematic liquid crystal, 15-40% of photo-polymerizable monomer, 2-15% of UV-absorbing dye, 0-25% of chiral additive and 0.5-5% of photoinitiator.

21 . The patterned phase delay film according to claim 19 wherein the heat-polymerizable liquid crystal mixture comprises, by mass percentage, 35-73% of small molecule nematic liquid crystal, 10-20% of heat-polymerizable monomer, 12-20% of curing agent and 5-25% of chiral additive.

Assignees

• Beijing Boe Display Tech Co
• Boe Technology Group Co Ltd

Inventors

• Wang Feifei
• Shao Xibin
• Wang Dan
• Lee Seungmin
• Zhang Honglin
• Zhao Hebin
• Dong Ting
• Qu Yingying

Classifications

• C09K19/586 Primary

  Optically active dopants; chiral dopants · CPC title

• C09K19/3809

  Polyesters; Polyester derivatives, e.g. polyamides · CPC title

• G02B5/3016

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

• G02F1/1341

  Filling or closing of cells · CPC title

• G02F1/133382

  Heating or cooling of liquid crystal cells other than for activation, e.g. circuits or arrangements for temperature control, stabilisation or uniform distribution over the cell · CPC title