Thermostable pigments, films and effect coatings, and mixtures for their production

• US 6,423,246 B1
• Filed: 04/10/2000
• Issued: 07/23/2002
• Est. Priority Date: 04/15/1999
• Status: Expired due to Term

• Current Assignee: Sicpa Holding SA
• Original Assignee: Consortium Fur Elektrochemische Industrie GmbH
• Inventors: Kasch, Michael, Kreuzer, Franz-Heinrich, Küpfer, Jürgen
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US09/546,040
• Time in Patent Office: 834 Days
• Field of Search: 252/299.01, 252/299.4, 252/299.7, 428/1.1, 106/493, 106/494, 106/499, 106/506
• US Class Current: 252/299.01
• CPC Class Codes: C09D 5/36 Pearl essence, e.g. coatings containing platelet-like pigments for pearl lustre
• CPC Class Codes: C09K 19/00 Liquid crystal materials
• CPC Class Codes: C09K 19/38 Polymers

Abstract

A mixture of crosslinkable liquid-crystalline substances having a chiral phase (LC mixture), containing polymerizable groups, where at least 90% of the polymerizable groups are part of molecules containing at least two polymerizable groups (crosslinker molecules), wherein from 3.2 to 15 mmol of polymerizable groups are present per g of LC mixture. The crosslinked pigments show little color shift in the presence of solvents or upon application to substrate different temperatures.

Claims

1. An LC mixture comprising crosslinkable liquid-crystalline substances having a chiral phase and containing polymerizable groups, wherein at least 90% of the polymerizable groups of said crosslinkable liquid-crystalline substances are part of crosslinker molecules containing at least two polymerizable groups, and wherein from 3.2 to 15 mmol of polymerizable groups are present per g of said LC mixture.

2. The LC mixture of claim 1, wherein the substances having a chiral phase containing polymerizable groups are low-molecular-weight, oligomeric or polymeric substances or mixtures of these substances.

3. The LC mixture of claim 1, comprising:

a) a single compound or mixtures of compounds of the general formula Y¹—

A¹—

M¹—

A²—

Y², in which Y¹ and Y² are identical or different polymerizable groups;

A¹ and A² are identical or different radicals of the general formula C_nH_2n, in which n is an integer from 0 to 20, and one or more methylene groups may be replaced by oxygen atoms;

M¹ has the general formula —

R¹—

X¹—

R²—

X²—

R³—

X³—

R⁴—

, where R¹, R², R³ and R⁴ are identical or different divalent radicals selected from the group consisting of —

O—

, —

COO—

, —

CONH—

, —

CO—

, —

S—

, —

C≡

C—

, —

CH═

CH—

, —

N═

N— and

—

N═

N(O)—

, wherein R²—

X²—

R³ or R²—

X² or R²—

X²—

R³—

X³ can be a C—

C bond, and X¹, X² and X³ are identical or different radicals selected from the group consisting of 1,4-phenylenes, 1,4-cyclohexylenes, arylenes, and heteroarylenes having 6 to 10 atoms in a heteroaryl ring containing 1 to 3 heteroatoms from the group consisting of O, N and S, optionally substituted by one or more of B¹, B² or B³, and cycloalkylenes having 3 to 10 carbon atoms which are substituted by one or more of B¹, B², or B³, where B¹, B² and B³ are identical or different substituents selected from the group consisting of —

H, C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, C₁-C₂₀-alkylthio, C₁-C₂₀-alkylcarbonyl, C₁-C₂₀-alkoxycarbonyl, C₁-C₂₀-alkylthiocarbonyl, —

OH, —

F, —

Cl, —

Br, —

I, —

CN, —

NO₂, formyl, acetyl, and alkyl, alkoxy or alkylthio radicals having 1-20 carbon atoms which are optionally interrupted by ether oxygen, thioether sulfur or ester groups, with

b) chiral compounds of the general formula V¹—

A¹—

W¹—

Z—

W²—

A²—

V², in which V¹and V² are identical or different and are an acrylate, methacrylate, epoxide, vinyl ether or vinyl ester radical, an isocyanate radical, C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, C₁-C₂₀-alkylthio, C₁-C₂₀-alkoxycarbonyl, C₁-C₂₀-alkylthiocarbonyl, —

OH, —

F, —

Cl, —

Br, —

I, —

CN, —

NO₂, formyl, acetyl, and alkyl, alkoxy or alkylthio radical having 1-20 carbon atoms which are optionally interrupted by ether oxygen, thioether sulfur or ester groups,

A¹ and A² are as defined above, and

W¹ and W² have the general formula —

R¹—

X¹—

R²—

X²—

R³—

, where

R¹, R² and R³ are as defined above and R² or R²—

X² may alternatively be a C—

C bond, and

X¹and X² are as defined above, and

Z is a divalent chiral radical from the group consisting of dianhydrohexitols, hexoses, pentoses, binaphthyl derivatives, biphenyl derivatives, tartaric acid derivatives and optically active glycols,

wherein the concentration of the polymerizable groups, of which at least 90% are on crosslinker molecules containing at least two polymerizable groups, in the mixture as a whole is from 3.2 to 15 mmol/g.

4. The LC mixture of claim 2, comprising:

a) a single compound or mixtures of compounds of the general formula Y¹—

A¹—

M¹—

A²—

Y², in which Y¹and Y² are identical or different polymerizable groups;

A¹and A² are identical or different radicals of the general formula C_nH_2n, in which n is an integer from 0 to 20, and one or more methylene groups may be replaced by oxygen atoms;

M¹ has the general formula —

R¹—

X¹—

R²—

X²—

R³—

X³—

R⁴—

, where R¹, R², R³ and R⁴ are identical or different divalent radicals selected from the group consisting of —

O—

, —

COO—

, —

CONH—

, —

CO—

, —

S—

, —

C≡

C—

, —

CH═

CH—

, —

N═

N— and

—

N═

N(O)—

, wherein R²—

X²—

R³ or R²—

X² or R²—

X²—

R³—

X³ can be a C—

C bond, and X¹, X² and X³ are identical or different radicals selected from the group consisting of 1,4-phenylenes, 1,4-cyclohexylenes, arylenes, and heteroarylenes having 6 to 10 atoms in a heteroaryl ring containing 1 to 3 heteroatoms from the group consisting of O, N and S, optionally substituted by one or more of B¹, B² or B³, and cycloalkylenes having 3 to 10 carbon atoms which are substituted by one or more of B¹, B², or B³, where B¹, B² and B³ are identical or different substituents selected from the group consisting of —

H, C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, C₁-C₂₀-alkylthio, C₁-C₂₀-alkylcarbonyl, C₁-C₂₀-alkoxycarbonyl, C₁-C₂₀-alkylthiocarbonyl, —

OH, —

F, —

Cl, —

Br, —

I, —

CN, —

NO₂, formyl, acetyl, and alkyl, alkoxy or alkylthio radicals having 1-20 carbon atoms which are optionally interrupted by ether oxygen, thioether sulfur or ester groups, with

b) chiral compounds of the general formula V¹—

A¹—

W¹—

Z—

W²—

A²—

V², in which V¹ and V² are identical or different and are an acrylate, methacrylate, epoxide, vinyl ether or vinyl ester radical, an isocyanate radical, C₁-C₂₀-alkyl, C₁-C₂₀-alkoxy, C₁-C₂₀-alkylthio, C₁-C₂₀-alkoxycarbonyl, C₁-C₂₀-alkylthiocarbonyl, —

OH, —

F, —

Cl, —

Br, —

I, —

CN, —

NO₂, formyl, acetyl, and alkyl, alkoxy or alkylthio radical having 1-20 carbon atoms which are optionally interrupted by ether oxygen, thioether sulfur or ester groups,

A¹ and A² are as defined above, and

W¹ and W² have the general formula —

R¹—

X¹—

R²—

X²—

R³—

, where

R¹, R² and R³ are as defined above and R² or R²—

X² may alternatively be a C—

C bond, and

X¹ and X² are as defined above, and

Z is a divalent chiral radical from the group consisting of dianhydrohexitols, hexoses, pentoses, binaphthyl derivatives, biphenyl derivatives, tartaric acid derivatives and optically active glycols,

wherein the concentration of the polymerizable groups, of which at least 90% are on crosslinker molecules containing at least two polymerizable groups, in the mixture as a whole is from 3.2 to 15 mmol/g.

5. The LC mixture of claim 3 wherein Y¹ and Y² individually are selected from the group consisting of acrylate, methacrylate, epoxide, isocyanate, hydroxyl, vinyl ether, and vinyl ester radicals.

6. The LC mixture of claim 4 wherein Y¹ and Y² individually are selected from the group consisting of acrylate, methacrylate, epoxide, isocyanate, hydroxyl, vinyl ether, and vinyl ester radicals.

7. The LC mixture of claim 3, which comprises from 70 to 99% by weight of compounds of the general formula Y¹—

A¹—

M¹—

A²—

Y² and from 1 to 30% by weight of compounds of the general formula V¹—

A¹—

W¹—

Z—

W²—

A²—

V².

8. The LC mixture of claim 4, which comprises from 70 to 99% by weight of compounds of the general formula Y¹—

A¹—

M¹—

A²—

Y² and from 1 to 30% by weight of compounds of the general formula V¹—

A¹—

W¹—

Z—

W²—

A²—

V².

9. An LC film or LC pigment comprising the crosslinked LC mixture of claim 1.

10. An LC film or LC pigment comprising the crosslinked LC mixture of claim 2.

11. An LC film or LC pigment comprising the crosslinked LC mixture of claim 3.

12. An LC film or LC pigment comprising the crosslinked LC mixture of claim 4.

13. An LC film or LC pigment comprising the crosslinked LC mixture of claim 5.

14. A process for the production of an LC film comprising applying an LC mixture as claimed in claim 1 in the liquid-crystalline state to a smooth substrate, aligning the LC mixture, three-dimensionally crosslinking the LC mixture, and detaching the film from the substrate.

15. A process for the production of an LC film comprising applying an LC mixture as claimed in claim 2 in the liquid-crystalline state to a smooth substrate, aligning the LC mixture, three-dimensionally crosslinking the LC mixture, and detaching the film from the substrate.

16. A process for the production of an LC film comprising applying an LC mixture as claimed in claim 3 in the liquid-crystalline state to a smooth substrate, aligning the LC mixture, three-dimensionally crosslinking the LC mixture, and detaching the film from the substrate.

17. A process for the production of an LC film comprising applying an LC mixture as claimed in claim 4 in the liquid-crystalline state to a smooth substrate, aligning the LC mixture, three-dimensionally crosslinking the LC mixture, and detaching the film from the substrate.

18. A process for the production of LC pigments comprising comminuting an LC film as prepared by the process of claim 14 to give platelet-shaped particles.

19. A process for the production of LC pigments comprising comminuting an LC film as prepared by the process of claim 16 to give platelet-shaped particles.

20. A coating composition comprising LC pigments or LC films of claim 9.