Light control film

• US 9,638,979 B2
• Filed: 12/21/2007
• Issued: 05/02/2017
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Resonac Corp. (Resonac Holdings Corp.)
• Original Assignee: Hitachi Chemical Company Limited (Resonac Holdings Corp.)
• Inventors: Higashida, Osamu, Ogawa, Michio
• Primary Examiner(s): STACHEL, KENNETH J
• Application Number:
  US12/520,315
• Publication Number:
  US 20100047593A1
• Time in Patent Office: 3,420 Days
• Field of Search: None
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/172 based on a suspension of orientable dipolar particles, e.g. suspended particles displays
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]

Abstract

The present invention relates to a light control film, comprising:

two transparent electroconductive substrates; and

a light control layer sandwiched between the two transparent electroconductive substrates,

wherein the light control layer contains a resin matrix and a light control suspension dispersed in the resin matrix, and the concentration of the light control suspension in the vicinity of each of the transparent electroconductive substrates is smaller than that of the light control suspension in the middle in the thickness direction of the light control layer.

Claims

1. A light control film, comprising:

two transparent electroconductive substrates; and

a light control layer sandwiched between the two transparent electroconductive substrates,

wherein the light control layer contains a resin matrix and a light control suspension dispersed in the resin matrix as droplets having light control performance, where the light control suspension comprises a liquid dispersing medium and light control particles having a major axis and a minor axis dispersed in the liquid dispersing medium, where a concentration of the light control suspension, measured by observing a cross section in a thickness direction of the light control film when trisecting the light control layer into three equal thickness parts consisting of a vicinity region to each of the transparent electroconductive substrates, and a middle region of the light control layer to observe the existence of droplets of the light control suspension in each of the regions, in the vicinity region to each of the transparent electroconductive substrates is smaller than that of the light control suspension in the middle region in the thickness direction of the light control layer, and the light control particles are configured to have their major axes arranged in a direction parallel to an electric field when an electric field is applied, whereby light radiated into the light control film penetrates through the light control film, wherein the light control layer contains the resin matrix as an energy cured polymeric medium from each of both major surfaces, where the polymeric medium has a first major surface adjacent one of the two transparent electroconductive substrates and a second major surface adjacent another of the two transparent electroconductive substrates with the light control suspension dispersed in the polymeric medium as droplets, so that for the resin matrix the concentration of the light control suspension in the vicinity region to each of the transparent electroconductive substrates is smaller than that of the light control suspension in the middle region in the thickness direction of the light control layer for color evenness and adhesion with the two transparent electro-conductive substrates.

2. The light control film according to claim 1, wherein the resin matrix has therein no interfacial surface.

3. The light control film according to claim 1, wherein the resin matrix is formed from a polymeric medium comprising:

a silicone resin having a substituent having an ethylenically unsaturated bond; and

a photopolymerization initiator.

4. The light control film according to claim 1, wherein the light control suspension contains an acrylic acid ester oligomer having a fluoro group and a hydroxyl group.

5. The light control film according to claim 1, wherein an aspect ratio of the major axis to the minor axis of the light control particles is from 6 to 15.

6. The light control film according to claim 1, wherein an aspect ratio of the major axis to the minor axis of the light control particles is from 7 and 12.

7. The light control film according to claim 1, wherein an aspect ratio of the major axis to the minor axis of the light control particles is from 7.5 to 11.

8. The light control film according to claim 1, wherein the light control suspension contains the light control particles in an amount of 1 to 70% by weight of the light control suspension.

9. The light control film according to claim 1, wherein the light control suspension contains the light control particles in an amount of 4 to 50% by weight of the light control suspension.

10. The light control film according to claim 1, wherein the light control suspension contains the liquid dispersing medium in an amount of 30 to 99% by weight of the light control suspension.

11. The light control film according to claim 1, wherein the light control suspension contains the liquid dispersing medium in an amount of 50 to 96% by weight of the light control suspension.

12. The light control film according to claim 1, wherein the light control suspension is contained in the resin matrix in an amount of 1 to 100 parts by weight relative to 100 parts by weight of the resin matrix.

13. The light control film according to claim 1, wherein the light control suspension is contained in the resin matrix in an amount of 4 to 70 parts by weight relative to 100 parts by weight of the resin matrix.

14. The light control film according to claim 1, wherein the light control suspension is contained in the resin matrix in an amount of 6 to 60 parts by weight relative to 100 parts by weight of the resin matrix.

15. The light control film according to claim 1, wherein the light control suspension is contained in the resin matrix in an amount of 8 to 50 parts by weight relative to 100 parts by weight of the resin matrix.

16. The light control film according to claim 1, wherein the thickness of the light control layer is from 10 to 500 μ

m.

17. The light control film according to claim 1, wherein the thickness of the light control layer is from 20 to 100 μ

m.

18. The light control film according to claim 1, wherein each of the transparent electroconductive substrates comprises a transparent substrate with a transparent electroconductive film provided thereon, the transparent electroconductive film provided on each of the transparent electroconductive substrates being provided on a side of each transparent substrate adjacent the light control layer.