Salt-free composite marking based on chiral liquid crystal precursors comprising chiral acrylate dopants

Patent metadata

Field	Value
Publication number	US-2016264792-A1
Application number	US-201415034885-A
Country	US
Kind code	A1
Filing date	Nov 6, 2014
Priority date	Nov 8, 2013
Publication date	Sep 15, 2016
Grant date	—

Abstract

Disclosed is a substrate which has thereon a marking or layer comprising a salt-free cured chiral liquid crystal precursor composition which comprises one or more nematic compounds A and one or more chiral dopant compounds B which are capable of giving rise to a cholesteric state of the chiral liquid crystal precursor composition and are of formula (I) as set forth herein. A modifying resin made from one or more polymerizable monomers comprising an average of at least one ether functionality per polymerizable group is disposed between the substrate and the marking or layer and in contact with the marking or layer in one or more areas thereof. The modifying resin changes the position of a selective reflection band exhibited by the cured chiral liquid crystal precursor composition on the substrate in the one or more areas.

First claim

1 . A substrate having thereon a marking or layer comprising a cured chiral liquid crystal precursor composition, wherein the chiral liquid crystal precursor composition is salt-free and comprises (i) one or more nematic compounds A and (ii) one or more chiral dopant compounds B which are capable of giving rise to a cholesteric state of the chiral liquid crystal precursor composition and are of formula (I):

wherein:
R 1 , R 2 , R 3 , and R 4 each independently denote C 1 -C 6 alkyl and C 1 -C 6 alkoxy;
A 1 and A 2 each independently denote a group of formula —[(CH 2 ) y —O] z —C(O)—CH═CH 2 ;
m, n, o, and p each independently denote 0, 1, or 2;
y denotes 0, 1, 2, 3, 4, 5, or 6; and
z equals 0 if y equals 0 and z equals 1 if y equals 1 to 6;
and wherein a modifying resin made from one or more polymerizable monomers comprising an average of at least one ether functionality (—C—O—C—) per polymerizable group is disposed between the substrate and the marking or layer and in contact with the marking or layer in one or more areas thereof, the modifying resin changing a position of a selective reflection band exhibited by the cured chiral liquid crystal precursor composition on the substrate in the one or more areas.

2 . The substrate of claim 1 , wherein the one or more nematic compounds A comprise at least one compound that comprises at least one polymerizable group.

3 . The substrate of claim 2 , wherein the at least one polymerizable group comprises a group of formula H 2 C═CH—C(O)—.

4 . The substrate of claim 1 , wherein y in formula (I) equals 0.

5 . The substrate of claim 1 , wherein in formula (I) the total number of carbon atoms in R 1 , R 2 , R 3 , and R 4 does not exceed 8.

6 . The substrate of claim 1 , wherein in formula (I) at least two of m, n, o, and p denote 0.

7 . The substrate of claim 1 , wherein in formula (I) R 1 , R 2 , R 3 , and R 4 each independently denote C 1 -C 3 alkyl and C 1 -C 3 alkoxy.

8 . The substrate of claim 1 , wherein at least one of the one or more polymerizable monomers for providing the modifying resin comprises at least two polymerizable groups having an unsaturated carbon-carbon bond.

9 . The substrate of claim 1 , wherein at least one of the one or more polymerizable monomers for providing the modifying resin comprises at least one polymerizable group of formula H 2 C═CH—C(O)— or H 2 C═C(CH 3 )—C(O)—.

10 . The substrate of claim 1 , wherein the one or more polymerizable monomers comprise an average of at least two ether functionalities per polymerizable group.

11 . The substrate of claim 1 , wherein the ether functionalities are provided by alkyleneoxy units having from 2 to 4 carbon atoms.

12 . The substrate of claim 1 , wherein at least a part of the ether functionalities is provided by ethyleneoxy groups.

13 . The substrate of claim 1 , wherein at least 80 mole-% of the one or more polymerizable monomers comprise at least one ether functionality.

14 . The substrate of claim 1 , wherein at least 90 mole-% of the one or more polymerizable monomers comprise at least four ether functionalities.

15 . The substrate of claim 1 , wherein the modifying resin comprises a dried aqueous resin.

16 . The substrate of claim 1 , wherein the modifying resin shifts a position of the selective reflection band exhibited by the salt-free cured chiral liquid crystal precursor composition by at least 5 nm.

17 . The substrate of claim 1 , wherein at least a part of the selective reflection band exhibited by the cured chiral liquid crystal precursor composition that has been shifted by the modifying resin is in the visible range.

18 . A method of providing a marking on a substrate, wherein the method comprises:
a) applying onto a surface of a substrate which carries a modifying resin made from one or more polymerizable monomers comprising an average of at least one ether functionality (—C—O—C—) per polymerizable group in one or more areas of the surface of the substrate a salt-free curable chiral liquid crystal precursor composition comprising (i) one or more nematic compounds A and (ii) one or more chiral dopant compounds B which are capable of giving rise to a cholesteric state of the chiral liquid crystal precursor composition and are of formula (I):

wherein:
R 1 , R 2 , R 3 , and R 4 each independently denote C 1 -C 6 alkyl and C 1 -C 6 alkoxy;
A 1 and A 2 each independently denote a group of formula —[(CH 2 ) y —O] z —C(O)—CH═CH 2 ;
m, n, o, and p each independently denote 0, 1, or 2;
y denotes 0, 1, 2, 3, 4, 5, or 6; and
z equals 0 if y equals 0 and z equals 1 if y equals 1 to 6;
in such a way that the composition covers at least a part of the one or more areas carrying the modifying resin and also covers at least one area of the surface that does not carry the modifying resin,

b) heating the applied composition to bring same to a chiral liquid crystal state; and
c) curing the composition in the chiral liquid crystal state;

and wherein the modifying resin shifts the position of the selective reflection band exhibited by the cured chiral liquid crystal precursor composition on the substrate in the one or more areas in which it is present.

19 . A substrate obtainable by the method of claim 18 .

20 . A method of changing a position of a selective reflection band exhibited by a cured chiral liquid crystal precursor composition, wherein the composition is salt-free and comprises (i) one or more nematic compounds A and (ii) one or more chiral dopant compounds B which are capable of giving rise to a cholesteric state of the chiral liquid crystal precursor composition and are of formula (I):

wherein:
R 1 , R 2 , R 3 , and R 4 each independently denote C 1 -C 6 alkyl and C 1 -C 6 alkoxy;
A 1 and A 2 each independently denote a group of formula —[(CH 2 ) y —O] z —C(O)—CH═CH 2 ;
m, n, o, and p each independently denote 0, 1, or 2;
y denotes 0, 1, 2, 3, 4, 5, or 6; and
z equals 0 if y equals 0 and z equals 1 if y equals 1 to 6;
and wherein the method comprises contacting the composition with a modifying resin which is made from one or more polymerizable monomers comprising an average of at least one ether functionality (—C—O—C—) per polymerizable group and is capable of changing a position of a selective reflection band exhibited by the salt-free cured chiral liquid crystal precursor composition.

21 . The method of claim 20 , wherein a position of the selective reflection band is shifted by the modifying resin by at least 5 nm.

22 . The method of claim 20 , wherein the cured chiral liquid crystal precursor composition is adapted to form part of a marking on a substrate.

Assignees

• Sicpa Holding Sa

Inventors

• Jauzein Tristan
• Mayade Sabine

Classifications

• C09D4/06

  {Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond} in combination with a macromolecular compound other than an unsaturated polymer of groups C09D159/00 - C09D187/00 · CPC title

• C09K2019/0448

  the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate · CPC title

• C09K19/3809

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

• C09K19/588

  Heterocyclic compounds · CPC title

• C09K19/38

  Polymers · CPC title