PRE-POLYMER FORMULATIONS FOR LIQUID CRYSTAL DISPLAYS

• US 20080108727A1
• Filed: 11/08/2006
• Published: 05/08/2008
• Est. Priority Date: 11/08/2006
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Lewandowski, Kevin M., Roberts, Ralph R., Stay, Matthew S., Wardhana, Jane K., Hite, Amy J.
• Granted Patent: US 7,648,645 B2
• Time in Patent Office: Days
• US Class Current: 522/172
• CPC Class Codes: C08G 77/14 containing silicon bound to oxygen-containing groups C08G77/045 takes precedence
• CPC Class Codes: C09D 4/00 Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
• CPC Class Codes: C09K 19/406 containing silicon
• CPC Class Codes: C09K 19/54 Additives having no specific mesophase characterised by their chemical composition
• 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 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: C09K 2323/021 Inorganic, e.g. glass or silicon oxide
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/033 Silicon compound, e.g. glass or organosilicon
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals

Abstract

A pre-polymer/liquid crystal composition is disclosed and includes, a liquid crystal component, a photo polymerization initiator, and a polymer precursor component. The polymer precursor component includes at least, a silane monomer, reactive (meth)acryloxy monomer or oligomer, and an ester, urethane, or (meth)acrylate based polymer or oligomer, bearing one or more reactive (meth)acrylate groups. Methods of forming a bistable electro-optical device are also disclosed.

Claims

7-1. A composition according to claim 1, wherein the second monomer is trimethylopropane triacrylate, hexanediol dimethacrylate, hexanediol diacrylate, butanediol dimethacrylate, ethylene glycol diacrylate, or ethylene glycol dimethacryalte.

13. A method of forming a bistable electro-optical device comprising:

providing a first substrate having a first conductive inner surface;

providing a second substrate having a second conductive inner surface, wherein at least one of the first substrate or second substrate is transparent to visible light; and

disposing a composition on the first conductive inner surface, the composition comprising;

(a) a liquid crystal component,

(b) a photo polymerization initiator; and

(c) a polymer precursor component comprising;

(i) 40 to 95% wt of a first monomer of structure (I)

R¹_mR²_pSi(X)_4-m-p 

 

(I)

wherein,

R¹ is a acryloxy, methacryoxy, or (meth)acryloxyalkyl;

R² is independently selected from hydrogen, (C₁-C₁₂)alkyl, (C₆-C₁₂)aryl, or (C₇-C₁₇)arylalkyl;

X is hydrolysable or non-hydrolysable group;

m is an integer from 1 to 3 and (m+p) is an integer from 1 to 3;

(ii) 0.05 to 55% wt of one or more second monomers of structure (II)

R³_n-R⁴

wherein,

R³ is independently selected from acryloxy or methacryloxy,

R⁴ is (C₁-C₂₀)alkyl,

n is an integer from 1 to 4;

(iii)₅ to 65% wt of a ester, urethane, or (meth)acrylate based polymer or oligomer, bearing one or more reactive (meth)acrylate groups;

disposing the second conductive surface on the composition; and

curing the composition to formed a cured composition.

14. The method according to claim 13, wherein the curing step comprises curing the composition to form a cured composition having a thickness in a range from 1 to 15 micrometers.

15. The method according to claim 14, wherein the curing step comprises radiation curing the composition at a range from 0.1 to 10 mW/cm².

16. The method according to claim 14, wherein the curing step comprises radiation curing the composition at a range from 0.2 to 3 mW/cm².

17. The method according to claim 13, wherein the providing the first substrate comprises providing a first flexible transparent polymeric substrate or the providing a second substrate comprises providing a second flexible transparent polymeric substrate.

18. The method according to claim 13, wherein the method is conducted on a roll-to-roll apparatus.

19. The method according to claim 13, wherein the curing step comprises curing the composition to form a cured composition having a disperse liquid crystal phase and a continuous poly(meth)acrylate phase.

20. The method according to claim 13, wherein the providing the first substrate comprises providing a first substrate having a first conductive inner surface being a patterned electrode or the providing the second substrate comprises providing a second substrate having a second conductive inner surface being a patterned electrode.

21. The method according to claim 13, wherein the disposing step comprises disposing the composition comprising a cholesteric liquid crystal material.

22. The method according to claim 13, wherein the disposing step comprises disposing the composition comprising a nematic liquid crystal material.