Compositions comprising functionalized polyvinyl alcohol and nanocapsules containing a liquid crystalline medium

Patent metadata

Field	Value
Publication number	US-10793776-B2
Application number	US-201816153023-A
Country	US
Kind code	B2
Filing date	Oct 5, 2018
Priority date	Oct 5, 2017
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

The use of functionalized polymerizable polyvinyl alcohol as a binder or matrix for a dispersion of nanoparticles, wherein the nanoparticles respectively comprise a polymeric shell and a core containing a liquid crystalline medium. Composites comprising the functionalized polymer and the nanocapsules, methods for preparing the composites and electro-optical devices containing such composites.

First claim

The invention claimed is:

1. A method for preparing a composite, wherein the method comprises
(i) providing nanocapsules which comprise a polymeric shell and a core containing a liquid crystalline medium, and
(ii) mixing the nanocapsules with a polymer comprising one or more of the repeating units A and/or B

and one or more of the repeating units C and/or D

wherein
Sp 1 and Sp 2 respectively represent a spacer group,
X 11 represents CH 2 , CO, S—CO or NH—CO,
y is, independently in each occurrence, 0 or an integer from 1 to 10,
X 12 represents, independently in each occurrence, 0, S, CO, NH or an ester group,
X 13 represents, independently in each occurrence, 0, S, CO, NH or single bond, and
R 11 is a polymerizable group.

2. The method according to claim 1 , wherein the polymer which is mixed with the nanocapsules in step (ii) has an average molecular weight within the range of 5,000 g/mol to 250,000 g/mol.

3. The method according to claim 1 , wherein
the amount of the repeating unit A in the polymer is in the range from 0 to 90 mol %, and/or
the amount of the repeating unit B in the polymer is in the range from 1 mol % to 98 mol %, and/or
the amount of the repeating unit C in the polymer is in the range from 0 mol % to 80 mol %, and/or
the amount of the repeating unit D in the polymer is in the range from 0 mol % to 80 mol %,

and
wherein the combined amounts of the repeating units A, B, C and D, if respectively present, in the polymer is 100 mol % or less.

4. The method according to claim 1 , wherein R 11 is an acryloyl group or a methacryloyl group.

5. The method according to claim 1 , wherein di- or multireactive monomeric or oligomeric polymerizable compounds are further comprised in the composite.

6. The method according to claim 1 , wherein in step (ii) the nanocapsules are dispersed in the polymer to prepare a dispersion, and wherein subsequently the dispersion is arranged as a layer supported on a substrate or as a layer between two opposing substrates.

7. The method according to claim 1 , wherein the method further comprises polymerization of the polymerizable groups of the prepared composite.

8. A composite obtained by carrying out the method according to claim 1 .

9. A composite, comprising
nanocapsules which comprise a polymeric shell and a core containing a liquid crystalline medium, and
a polymer containing the nanocapsule dispersed therein comprising one or more of the repeating units A and/or B and one or more of the repeating units C and/or D:

wherein
Sp 1 and Sp 2 respectively represent a spacer group,
X 11 represents CH 2 , CO, S—CO or NH—CO,
y is, independently in each occurrence, O or an integer from 1 to 10,
X 12 represents, independently in each occurrence, O, S, CO, NH or an ester group,
X 13 represents, independently in each occurrence, O, S, CO, NH or single bond, and
R 11 is a polymerizable group.

10. The composite according to claim 9 , wherein the liquid crystalline medium comprises one or more compounds of formula I
R-A-Y-A′-R′  I

wherein
R and R′ denote, independently of one another, a group selected from F, CF 3 , OCF 3 , CN, and straight-chain or branched alkyl or alkoxy having 1 to 15 carbon atoms or straight-chain or branched alkenyl having 2 to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF 3 or mono- or polysubstituted by halogen and wherein one or more CH 2 groups may be, in each case independently of one another, replaced by —O—, —S—, —CO—, —COO—, —OCO—, —OCOO— or —C≡C— in such a manner that oxygen atoms are not linked directly to one another,
A and A′ denote, independently of one another, a group selected from -Cyc-, -Phe-, -Cyc-Cyc-, -Cyc-Phe-, -Phe-Phe-, -Cyc-Cyc-Cyc-, -Cyc-Cyc-Phe-, -Cyc-Phe-Cyc-, -Cyc-Phe-Phe-, -Phe-Cyc-Phe-, -Phe-Phe-Phe- and the respective mirror images thereof, wherein Cyc is trans-1,4-cyclohexylene, in which one or two non-adjacent CH 2 groups may be replaced by O,
and wherein Phe is 1,4-phenylene, in which one or two non-adjacent CH groups may be replaced by N and which may be substituted by one or two F, and

Y denotes single bond, —COO— —CH 2 CH 2 —, —CF 2 CF 2 —, —CH 2 O—, —CF 2 O—, —CH═CH—, —CF═CF— or —C≡C—.

11. The composite according to claim 10 , wherein one or more compounds of the formula I are selected from the compounds of formulae Ia, Ib, Ic and Id

wherein
R 1 , R 2 , R 3 , R 4 , R 5 and R 6 denote, independently of one another, straight-chain or branched alkyl or alkoxy having 1 to 15 carbon atoms or straight-chain or branched alkenyl having 2 to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF 3 or mono- or polysubstituted by halogen and wherein one or more CH 2 groups may be, in each case independently of one another, replaced by —O—, —S—, —CO—, —COO—, —OCO—, —OCOO— or —C≡C— in such a manner that oxygen atoms are not linked directly to one another,
X 1 and X 2 denote, independently of one another, F, CF 3 , OCF 3 or CN,
L 1 , L 2 , L 3 , L 4 and L 5 are, independently of one another, H or F,
i is 1 or 2, and
j and k are, independently of one another, 0 or 1.

12. A switching layer, comprising nanocapsules which comprise a polymeric shell and a core containing a liquid crystalline medium, wherein the nanocapsules are dispersed in a polymeric binder which polymeric binder comprises a polymer obtained by polymerizing a polymer comprising one or more of the repeating units A and/or B and one or more of the repeating units C and/or D:

wherein
Sp 1 and Sp 2 respectively represent a spacer group,
X 11 represents CH 2 , CO, S—CO or NH—CO,
y is, independently in each occurrence, O or an integer from 1 to 10,
X 12 represents, independently in each occurrence, O, S, CO, NH or an ester group,
X 13 represents, independently in each occurrence, O, S, CO, NH or single bond, and
R 11 is a polymerizable group.

13. A light-modulation element which comprises a composite according to claim 8 .

14. A light-modulation element which comprises a switching layer according to claim 12 .

15. An electro-optical device, comprising a composite according to claim 8 .

16. An electro-optical device, comprising a switching layer according to claim 12 .

17. The composite of claim 9 , wherein the polymer has an average molecular weight within the range of 5,000 g/mol to 250,000 g/mol.

18. The composite of claim 9 , wherein
the amount of the repeating unit A in the polymer is in the range from 0 to 90 mol %, and/or
the amount of the repeating unit B in the polymer is in the range from 1 mol % to 98 mol %, and/or
the amount of the repeating unit C in the polymer is in the range from 0 mol % to 80 mol %, and/or
the amount of the repeating unit D in

Assignees

• Merck Patent Gmbh

Inventors

• Arasi Hassan
• Namutebi Mariam
• Tuffin Rachel

Classifications

• C09K2219/03

  in the form of films, e.g. films after polymerisation of LC precursor · CPC title

• C09K2019/123

  Ph-Ph-Ph · CPC title

• C09K19/20

  linked by a chain containing carbon and oxygen atoms as chain links, e.g. esters {or ethers} · CPC title

• C09K2019/181

  Ph-C≡C-Ph · CPC title

• C08K9/04

  Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)} · CPC title