HK1194331A - Substrate with a modified liquid crystal polymer marking - Google Patents

Description

Substrates with modified liquid crystalline polymer marking

Background

1. Field of the invention

The present invention relates to a marking on an article or substrate, said marking being based on a chiral nematic (also called cholesteric) liquid crystal precursor composition. Before curing the chiral liquid crystal precursor composition in the chiral liquid crystal state, at least one optical property exhibited by the composition is modified in at least one region of the article or substrate by two different types of modifiers.

2. Discussion of background information

Counterfeiting is no longer a national or regional issue, but rather a worldwide issue, which has an impact not only on the manufacturer, but also on the consumer. Counterfeiting is an important problem for goods such as clothing and watches, but becomes even more serious as it affects medicine and pharmaceuticals. Thousands of people die of counterfeit drugs every year around the world. Counterfeiting also has an impact on government revenue, i.e., it affects taxes, such as cigarette and wine, because of the existence of the black market, where it is not possible to track and track counterfeit (smuggled, diverted, etc.) products that do not have valid tax labels.

Many solutions have been proposed to make counterfeiting impossible or at least very difficult and/or expensive, such as RFID solutions or the use of invisible inks.

More recently, security features have emerged and are used to authenticate genuine products such as pharmaceuticals and to avoid counterfeiting. This technique is based on optically variable inks. The principle is based on the observable difference in color of a marking made with optically variable ink from different angles when marking packaging, security documents, etc. (the "viewing angle dependent color").

Optically variable inks provide not only first line identification of humans, but also promote machine readability. A number of patents describe such security products, their compositions and their applications. One example of many types of optically variable inks is a class of compounds called cholesteric liquid crystals. When illuminated with white light, the cholesteric liquid crystal structure reflects light of a color that depends on the material and that generally varies with viewing angle and temperature. The cholesteric material itself is colorless and the color observed is a result of the physical reflection effect at a given temperature of the cholesteric helix structure employed in the chiral liquid crystal precursor composition. See, e.g., j.l. fergason, Molecular Crystals, volume 1, page 293-307 (1966), the entire disclosure of which is incorporated herein by reference.

EP-A-1381520 and EP-A-1681586, the entire disclosures of which are incorporated herein by reference, disclose birefringence markers and methods of applying them in the form of ｃA liquid crystal layer having ｃA non-uniform pattern of regions of different thickness. The applied liquid crystal coating or layer can provide a hidden image on the reflective substrate that is not visible when viewed under unpolarized light but is made visible under polarized light or with the aid of a polarizing filter.

U.S. patent No.5,678,863, the entire disclosure of which is incorporated herein by reference, discloses a method of authenticating a value document comprising a paper or polymeric region having transparent and translucent characteristics. Liquid crystal material is applied to this region to produce different optical effects when viewed in transmitted and reflected light. The liquid crystal material is in liquid form at room temperature and must be encapsulated in a container such as a microcapsule to be suitable for use in a printing process such as gravure, rubber roller, spray or ink jet printing.

The ordered liquid crystalline state depends on the presence of the chiral dopant. Nematic liquid crystals without chiral dopants exhibit a molecular arrangement characterized by its birefringence. Nematic polymers are known, for example, from EP-A-O216712, EP-A-O847432 and U.S. Pat. No.6,589,445, the entire disclosures of which are incorporated herein by reference.

As noted above, liquid crystal-based security features provide first line recognizability by consumers as well as retailers and manufacturers of food and products. As with many other security features used in the marketplace, there is always an incentive for counterfeiting to duplicate these security features and thus mislead consumers and retailers. In view of the above, there is still a need to improve the safety of liquid crystalline polymer materials based on liquid crystalline precursors.

One possibility to enhance the security level of chiral liquid crystal polymer films seems to be to superimpose a code on the liquid crystal polymer film in the form of a pattern, a mark, a barcode, etc. However, there is always this risk: the counterfeiter tampers with the code and manually applies it to the liquid crystal polymer film.

A second possibility to overcome this problem is to insert a code into the liquid crystal polymer film. For example, U.S. Pat. No.6,207,240, the entire disclosure of which is incorporated herein by reference, describes effect coatings of Cholesteric Liquid Crystal Polymers (CLCP) having a viewing-angle dependent color of reflection, further comprising an absorptive pigment having a specific absorptive color. Markings such as symbols or text are produced in the CLCP coating by laser radiation. The laser radiation carbonizes the CLCP material in the irradiated area. Thus, the color of the CLCP-coated substrate, or the color of the absorbing pigment incorporated in the CLCP, becomes visible in the irradiated area. However, this method requires a high power laser to carbonize the material and make the logo visible.

Another possibility is described in US2006/0257633A1, the entire disclosure of which is incorporated herein by reference, which applies not only to liquid crystal polymers, but also to polymers in general. The method comprises the following steps: the osmotic agent is applied to a predetermined area on the surface of the polymeric substrate and the supercritical fluid is contacted with the surface of the polymeric substrate to which the osmotic agent has been applied to cause the osmotic agent to penetrate into the polymeric substrate. The process allows to selectively (partially) modify a portion of the surface of the polymer. However, for industrial processes, where high marking speeds are required for a large number of articles, the process is complex and expensive to perform.

One of the drawbacks of the above-mentioned methods is the lack of ability to modify the chiral liquid crystalline polymer layer in a selective and controllable manner and to produce strong and reliable markings or codes that are difficult to reproduce and compatible with the production line (preparing articles such as passports, packaging, etc.).

Summary of The Invention

The present invention provides indicia on an article or substrate. The marking comprises a (continuous or discontinuous) layer or pattern of a chiral liquid crystal polymer composition, said layer or pattern exhibiting an initial set of optical properties and being prepared by curing a chiral liquid crystal precursor composition in a chiral liquid crystal state. The layer or pattern comprises:

(1) one or more areas having a first modified set of optical properties, the first modified set of optical properties being different from the initial set of optical properties and being obtainable by contacting the chiral liquid crystal precursor composition in the one or more first areas with a first modifying agent;

(2) one or more second areas having a second modified set of optical properties, different from the initial set of optical properties and different from the first modified set of optical properties, and obtainable by contacting the chiral liquid crystal precursor composition in the one or more second areas with a second modifying agent, the second modifying agent being of a different type than the first modifying agent.

In one aspect of the identification, at least one of the one or more first areas may partially or completely overlap with the at least one second area and/or at least one of the one or more second areas may partially or completely overlap with the at least one first area.

In another aspect of the identification, at least one of the one or more first areas may not overlap any second areas and/or at least one of the one or more second areas may not overlap any first areas.

In yet another aspect identified herein, the initial and first and second sets of modified optical properties differ in at least one property of light reflected by the chiral liquid crystal polymer composition. For example, the at least one property may be selected from the spectrum, polarization, and λ of the reflected light_maxOne or more of the above.

In yet another aspect of the identification, the initial and first and second sets of modified optical properties can include at least one property exhibiting an optically anisotropic state of the chiral liquid crystal polymer composition.

In another aspect, a chiral liquid crystal precursor composition can comprise (i) one or more nematic compounds a, (ii) one or more chiral dopant compounds B capable of producing a cholesteric state of the chiral liquid crystal precursor composition, and (iii) at least one salt that changes the maximum wavelength of the selective reflection band exhibited by the polymer composition as compared to the maximum wavelength of the selective reflection band exhibited by the polymer composition without the at least one salt.

In one aspect, the one or more nematic compounds a and the one or more chiral dopant compounds B may comprise at least one compound comprising at least one polymerizable group. At least one polymerizable group can comprise, for example, an unsaturated carbon-carbon bond, such as of the formula H₂C = CH-C (o) -group.

In another aspect, the one or more nematic compounds a and all of the one or more chiral dopant compounds B may comprise at least one polymerizable group.

In yet another aspect, a chiral liquid crystal precursor composition can comprise at least one chiral dopant compound B of formula (I):

wherein:

R₁、R₂、R₃、R₄、R₅、R₆、R₇and R₈Each independently represents C₁-C₆Alkyl and C₁-C₆An alkoxy group;

A₁and A₂Each independently represents a group of formulae (i) - (iii):

(i)-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(ii)-C(O)-D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(iii)-C(O)-D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

D₁a group represented by the formula:

D₂a group represented by the formula:

m, n, o, p, q, r, s and t each independently represent 0, 1 or 2;

y represents 0, 1, 2,3, 4, 5 or 6;

if y is equal to 0, then z is equal to 0, and if y is equal to 1-6, then z is equal to 1.

In another aspect, the at least one salt may be selected from metal salts and ammonium salts. For example, the at least one salt may comprise at least one of: lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium bromide, lithium chloride, tetrabutylammonium perchlorate, tetrabutylammonium chloride, tetrabutylammonium tetrafluoroborate, tetrabutylammonium bromide, sodium carbonate, sodium chloride and sodium nitrate. In another aspect, the at least one salt may comprise lithium perchlorate.

In another aspect identified herein, the chiral liquid crystal precursor composition can be in an initial optically anisotropic state, and in one or more first areas, the initial optically anisotropic state can change to a first modified optically anisotropic state, and in one or more second areas, the initial optically anisotropic state can change to a second modified optically anisotropic state or convert to an optically isotropic state.

On the other hand, the chiral liquid crystal precursor composition may be in an initial chiral liquid crystal state, and in one or more first areas, the initial chiral liquid crystal state may be changed to a first modified chiral liquid crystal state by a first modifier, and in one or more second areas, the initial chiral liquid crystal state may be changed to a second modified chiral liquid crystal state or to an achiral liquid crystal state by a second modifier.

In yet another aspect identified herein, the first modifying agent can be a solid and/or semi-solid and the second modifying agent can be a fluid, and/or the first modifying agent can be substantially impermeable to the chiral liquid crystal precursor composition and the second modifying agent can be at least partially permeable to the precursor composition. A semi-solid is capable of supporting its own weight and retaining its shape while having the ability to flow, for example, under pressure.

In another aspect, the first modifying agent may be or may comprise a resin composed of one or more polymerizable monomers. Additionally, at least one of the one or more polymerizable monomers may comprise at least two unsaturated carbon-carbon bonds and/or may comprise at least one heteroatom selected from O, N and S. Merely by way of example, at least one of the one or more polymerizable monomers may comprise at least one monomer of formula H₂C = CH-C (O) -or H₂C=C(CH₃) The group of-C (O) -. Alternatively, the resin may comprise a radiation curable resin such as a UV curable resin and/or the resin may comprise an aqueous resin after drying.

In another aspect, the second modifier may be a fluid and selected from one or more of the following: (a) a modified composition comprising at least one compound selected from the group consisting of ketones having 3 to about 6 carbon atoms, alkyl esters and dialkylamides of carboxylic acids containing a total of 2 to about 6 carbon atoms, dihydrocarbyl sulfoxides containing a total of 2 to about 4 carbon atoms, and optionally substituted nitrobenzene, (b) a modified composition comprising at least one chiral liquid crystal precursor composition, and (c) a modified composition comprising at least one chiral dopant composition.

In yet another aspect of the present disclosure, the first modifying agent canA solid or semi-solid cured and/or dried resin selected from the group consisting of one or more polymerizable monomers, and both the first modifying agent and the second modifying agent alter the initial maximum wavelength (λ) of the selective reflection band exhibited by the chiral liquid crystal precursor composition in the chiral liquid crystal state_max)。

In yet another aspect, the first modifier and the second modifier act from opposite sides of a layer or pattern of the chiral liquid crystal precursor composition. For example, a first modifier may be placed between the substrate and the layer or pattern in one or more first areas, and a second modifier may be acted upon by the side opposite the substrate in one or more second areas.

In another aspect of the identification, the one or more first areas and/or the one or more second areas may be in the form of at least one of: images, pictures, logos, indicia, and patterns representing a code selected from one or more of: the 1-dimensional barcode, stacked 1-dimensional barcode, 2-dimensional barcode, 3-dimensional barcode, cloud of dots, network of lines and data matrix, and/or at least a portion of the layer or pattern may be in the form of at least one of: images, pictures, logos, indicia, and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, and data matrix.

In another aspect, the article or substrate may be or may comprise at least one of: a label, package, cassette, container or capsule comprising a food product, nutraceutical product, pharmaceutical product or beverage, a banknote, a credit card, a stamp, a tax label, a security seal, a security document, a passport, an identification card, a driver's license, an access card, a transportation ticket, an admission ticket, a voucher, an ink transfer film, a reflective film, an aluminium foil and a commercial product.

The invention also provides a method of providing a marking on an article or substrate and an article or substrate produced by the method. The method comprises the following steps:

a) applying to the surface of the article or substrate bearing the first modifying agent in one or more first areas a curable chiral liquid crystal precursor composition which assumes an initial chiral liquid crystal state upon heating it in such a way that the composition covers at least a portion of the one or more first areas, wherein the first modifying agent is capable of modifying the initial chiral liquid crystal state of the composition;

b) heating the applied composition to produce a first modified chiral liquid crystal state in one or more first areas and an initial chiral liquid crystal state, if any, in all other areas of the applied composition;

c) applying to one or more second areas of the applied composition at least one second modifying agent, which is of a different type than the first modifying agent and which (1) is capable of locally modifying the initial and/or first modified chiral liquid crystal state provided by b), or (2) is capable of locally modifying the initial and/or first modified chiral liquid crystal state provided by b) upon heating of the composition;

d) in the case of (2), heating the composition in at least the one or more second areas; and

e) curing/polymerizing the chiral liquid crystal precursor composition fully thus modified to produce a liquid crystal polymer marking on an article or substrate.

In one aspect of the method, at least one of the one or more first areas may partially or completely overlap with the at least one second area, and/or at least one of the one or more second areas may partially or completely overlap with the at least one first area.

In another aspect of the method, at least one of the one or more first areas may not overlap any second areas, and/or at least one of the one or more second areas may not overlap any first areas.

In another aspect of the method of identifying of the present invention, the initial and first and second sets of modified optical properties can differ in at least one property of light reflected by the chiral liquid crystal polymer composition. For example,at least one property selected from the spectrum, polarization and λ of the reflected light_maxOne or more of (a).

In yet another aspect of the method, the initial and first and second sets of modified optical properties can comprise at least one property that exhibits an optically anisotropic state of the chiral liquid crystal polymer composition and/or exhibits a conversion of the optically anisotropic state of the composition to an optically isotropic state.

In another aspect, a chiral liquid crystal precursor composition can comprise: (i) one or more nematic compounds a, (ii) one or more chiral dopant compounds B in a cholesteric state capable of giving rise to a chiral liquid crystal precursor composition, and (iii) at least one salt which exhibits, with a polymer composition which does not contain at least one salt, a maximum wavelength (λ) of the selective reflection band_max) In contrast, the maximum wavelength (λ) of the selective reflection band exhibited by the polymer composition was varied_max)。

In one aspect, the one or more nematic compounds a and the one or more chiral dopant compounds B may comprise at least one compound comprising at least one polymerizable group. At least one polymerizable group can comprise, for example, an unsaturated carbon-carbon bond, such as of the formula H₂C = CH-C (O) -.

In another aspect, the one or more nematic compounds a and all of the one or more chiral dopant compounds B may comprise at least one polymerizable group.

In yet another aspect, a chiral liquid crystal precursor composition can comprise at least one chiral dopant compound B of formula (I):

wherein:

R₁、R₂、R₃、R₄、R₅、R₆、R₇and R₈Each independently represents C₁-C₆Alkyl and C₁-C₆An alkoxy group;

A₁and A₂Each independently represents a group of formulae (i) - (iii):

(i)-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(ii)-C(O)-D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(iii)-C(O)-D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

D₁a group represented by the formula:

D₂a group represented by the formula:

m, n, o, p, q, r, s and t each independently represent 0, 1 or 2;

y represents 0, 1, 2,3, 4, 5 or 6;

if y is equal to 0, then z is equal to 0, and if y is equal to 1-6, then z is equal to 1.

In another aspect, the at least one salt may be selected from metal salts and ammonium salts. For example, the at least one salt may comprise at least one of: lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium bromide, lithium chloride, tetrabutylammonium perchlorate, tetrabutylammonium chloride, tetrabutylammonium tetrafluoroborate, tetrabutylammonium bromide, sodium carbonate, sodium chloride and sodium nitrate. In another aspect, the at least one salt may comprise lithium perchlorate and/or lithium bromide.

In another aspect of the invention, the chiral liquid crystal precursor composition can be in an initial optically anisotropic state, and in one or more first areas, the initial optically anisotropic state can change to a first modified optically anisotropic state, and in one or more second areas, the initial optically anisotropic state can change to a second modified optically anisotropic state or convert to an optically isotropic state (depending on the nature of the second modifier, as described below).

In yet another aspect of the method of the present invention, the first modifying agent may be a solid and/or semi-solid and the second modifying agent may be a fluid, and/or the first modifying agent may be substantially impermeable to the chiral liquid crystal precursor composition and the second modifying agent may be at least partially permeable to the precursor composition.

In another aspect, the first modifying agent may be or may comprise a resin composed of one or more polymerizable monomers. Additionally, at least one of the one or more polymerizable monomers may comprise at least two unsaturated carbon-carbon bonds and/or may comprise at least one heteroatom selected from O, N and S. Merely by way of example, at least one of the one or more polymerizable monomers may comprise at least one monomer of formula H₂C = CH-C (O) -or H₂C=C(CH₃) The group of-C (O) -. Alternatively, the resin may comprise a radiation curable resin such as a UV curable resin and/or the resin may comprise an aqueous resin after drying.

In another aspect, the second modifier may be a fluid and selected from one or more of the following: (a) a modified composition comprising at least one compound selected from the group consisting of ketones having 3 to about 6 carbon atoms, alkyl esters and dialkylamides of carboxylic acids containing a total of 2 to about 6 carbon atoms, dihydrocarbyl sulfoxides containing a total of 2 to about 4 carbon atoms, and optionally substituted nitrobenzene, (b) a modified composition comprising at least one chiral liquid crystal precursor composition, and (c) a modified composition comprising at least one chiral dopant composition.

In yet another aspect of the method of the present inventionThe first modifying agent may be selected from a solid or semi-solid cured and/or dried resin prepared from one or more polymerizable monomers, and both the first modifying agent and the second modifying agent may alter the initial maximum wavelength (λ) of the selective reflection band exhibited by the chiral liquid crystal precursor composition in the chiral liquid crystal state_max)。

In yet another aspect of the method, step b) and/or step d) may comprise heating the chiral liquid crystal precursor composition to a temperature of about 55 ℃ to about 150 ℃.

In another aspect, the chiral liquid crystal precursor composition can be applied by at least one of: spray coating, knife coating, roll coating, screen coating, curtain coating, gravure printing, flexographic printing, screen printing, pad printing, continuous ink jet printing, drop-on-demand ink jet printing, and valve jet printing, and/or the chiral liquid crystal precursor composition can be applied in at least one of the following forms: (continuous or discontinuous) layers, images, pictures, logos, indicia and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

In another aspect of the method of the present invention, the first modification agent may be provided on the article or substrate in one or more first areas by at least one of: spray coating, knife coating, roll coating, screen coating, curtain coating, gravure printing, flexographic printing, offset printing, dry offset printing, letterpress printing, screen printing, pad printing, continuous inkjet printing, drop-on-demand inkjet printing, and valve jet printing, and/or the first modifier can be present in one or more first areas on the article or substrate in the form of at least one of: images, pictures, logos, indicia and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

In yet another aspect, the second modifier may be applied to the one or more second areas by at least one of: continuous ink jet printing, drop on demand ink jet printing, spray coating, and valve jet printing, and/or the second modifier may be applied to the one or more second areas in at least one of the following forms: images, pictures, logos, indicia and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

In yet another aspect, the article or substrate may be or may comprise at least one of: a label, package, cassette, container or capsule comprising a food, beverage, nutraceutical or pharmaceutical product, a banknote, a credit card, a stamp, a tax label, a security seal, a security document, a passport, an identification card, a driver's license, an access card, a transportation ticket, an admission ticket, a voucher, an ink transfer film, a reflective film, an aluminium foil and a commercial good.

Brief Description of Drawings

The invention is described in further detail in the following detailed description, with reference to the various figures as non-limiting examples of exemplary embodiments of the invention, and wherein:

FIG. 1 is a schematic diagram illustrating the procedure described in examples 1 and 2; and

figures 2 and 3 show different patterns that can be obtained by placing the first and second areas on the substrate in different ways.

Detailed Description

The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show structural details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.

The substrate or article used in the present invention is not particularly limited and may have various types. The substrate or article may for example (essentially) consist of or comprise one or more of the following: metal (for example in the form of a container for holding various items such as health food, pharmaceuticals, beverages or foodstuffs, for example a can, capsule or closed cassette), fabric, coating, glass (for example in the form of a container for holding various items such as health food, pharmaceuticals, beverages or foodstuffs, for example a bottle), cardboard (for example in the form of a package), paper and polymeric materials such as PET (polyethylene terephthalate) or polyethylene (for example in the form of a container or as part of a security document). It should be noted that these matrix materials are given by way of example only and do not limit the scope of the present invention. Generally, any substrate or article (which may not necessarily be flat and may be non-flat) whose surface is insoluble or only slightly soluble in the chiral liquid polymer chiral liquid crystal precursor composition is a suitable substrate for use in the present invention.

The matrix may advantageously have a dark or black surface or background at least in those areas to which the chiral liquid crystal precursor composition is applied. Without wishing to be bound by any theory, it is speculated that in the case of a dark or black background, the light transmitted by the cholesteric liquid crystal material is mainly absorbed by the background, whereby any residual backscattering from the background does not interfere with the visual perception of the reflection of the cholesteric liquid crystal material itself. In contrast, on a substrate with a light or white surface or background, the reflected color of the cholesteric liquid crystal material is less visible when compared to a black or dark background because of strong backscattering from the background. However, even in the case of a light or white background, the cholesteric liquid crystal material can be identified by means of a circular polarizing filter, since it selectively reflects only one of the two possible circularly polarized light components, depending on its chiral helical structure. In addition, even with a light or white background, the optical properties of chiral liquid-crystalline polymers can be measured with physical means, for example λ_max. The substrates of the invention may further comprise other security elements, such as organic and/or inorganic pigments, dyes, flakesOptical color-changing elements, magnetic pigments, and the like.

The present invention identifies a (continuous or discontinuous) layer or pattern comprising a cured chiral liquid crystal precursor composition (= chiral liquid crystal polymer composition) exhibiting an initial set of optical properties in a chiral liquid crystal state. In addition to the one or more areas showing the initial set of optical properties (i.e. where no modifier is applied), the layer or pattern optionally (and preferably) comprises (1) one or more areas (e.g. 1, 2,3, 4, 5,6, 10, 15 or 20 first areas, which in the case of a data matrix may be 256 areas when constituting a 16 x 16 data matrix) comprising a first set of modified optical properties which is different from the initial set of optical properties and which may be obtained by contacting the chiral liquid crystal precursor composition in the uncured state in the one or more first areas with the first modifier, and (2) one or more second areas (e.g. 1, 2,3, 4, 5,6, 10, 15 or 20 second areas) having a second set of modified optical properties, in the case of a data matrix, when constituting a 16 x 16 data matrix, this may be 256 areas) different from the initial set of optical properties and different from the first set of modified optical properties and obtainable by contacting the chiral liquid crystal precursor composition in the uncured state in one or more second areas with a second modifying agent of a type different from the first modifying agent. In this regard, it is understood that the first and second sets of modified optical properties are different, it being sufficient for these sets to differ in at least one and only one optical property. In other words, the first and second modified optical property sets may comprise the same optical property, provided that the (at least) one optical property comprised therein is different.

The layer or pattern may comprise more than two different areas (i.e. in addition to one or more first areas, one or more second areas, and optionally one or more areas having an initial set of optical properties), wherein the initial set of optical properties has been modified by more than two different modifying agents, provided that there are at least two areas, wherein the two different types of modifying agents change the initial set of optical properties separately or together. For example, the layer may comprise 3,4, 5, etc. different areas, wherein 3,4, 5, etc. different modifiers alter the initial set of optical properties to produce 3,4, 5, etc. different sets of modified optical properties. In the following, for the sake of simplicity, usually only two modifiers, in particular two modifiers of different types, are used. However, it should be understood that the present invention is not limited to the use of only two modifiers of different types, nor to the use of only one modifier of a certain type. By way of example only, three modifiers of different types may be used, or one first modifier and two different second modifiers may be used.

In the present invention identification, there may further be at least one first area that does not overlap any second area, and/or there may be at least one second area that does not overlap the first area. In addition, there may be at least one first area that completely or partially overlaps the second area and/or there may be at least one second area that completely or partially overlaps the first area. This includes the case where the first area is larger than the second area and completely surrounds/covers the second area, and the case where the second area is larger than the first area and completely surrounds/covers the first area (see fig. 2). This also includes the case where the first and second areas are of the same size and completely coincide. Complete or partial overlap of the first and second areas results in a third area, i.e., an overlap area, resulting in a third set of modified optical properties (due to the combined action of the first and second modifiers). Of course, if more than two modifiers are used, the possible number of areas with different sets of optical properties increases exponentially, thereby further increasing the difficulty of counterfeiting the identification of the present invention. By way of example only, with three different modifiers, there may be one or more areas where only the first modifier is used, one or more areas where only the second modifier is used, one or more areas where only the third modifier is used, one or more areas where the first modifier and the second modifier are used, one or more areas where the first modifier and the third modifier are used, one or more areas where the second modifier and the third modifier are used, one or more areas where all three modifiers are used. It should be further understood that while the present identifiers generally comprise at least one area having an initial set of optical properties (i.e., not modified by any modifier), the presence of a corresponding area is not required. For example, the present invention also contemplates an indication wherein the entire area occupied by the chiral liquid crystal precursor composition in the chiral liquid crystal state is occupied (and modified) by the first modifier and wherein the (second) area (but not the entire area thereof) of one or more chiral liquid crystal precursor compositions is additionally modified by the second modifier (thereby producing an indication having one or more first areas modified by only the first modifier, the remainder being one or more third areas modified by both the first modifier and the second modifier).

The first and second modifiers used in the present invention are of different types. By way of example only, modifiers are of different types if they differ in their consistency (e.g., solid and/or semi-solid in one instance, and fluid (e.g., liquid) in another instance), and/or if they differ in their chemical structure (e.g., monomeric in one instance, and polymeric in another instance, or substantially organic in one instance, and substantially inorganic in another instance), and/or if they alter/modify the optical properties of the composition by different mechanisms, and/or if they alter/modify different light properties of the composition, and/or if they are capable of partially penetrating the uncured chiral liquid crystal precursor composition in one instance and substantially not penetrating the uncured chiral liquid crystal precursor composition in another instance.

The initial set and the first and second (and optionally third, fourth, etc.) sets of modified optical properties identified herein can differ in at least one property of light reflected by the chiral liquid crystal polymer composition in the chiral liquid crystal state. For example, the at least one property may be the spectrum (e.g., in the visible, infrared and/or UV range), polarization or λ of the reflected light_max(e.g., in the visible, infrared, and/or UV ranges). Lambda [ alpha ]_maxAnalysis can be used, for example, to measure the reflectance of a sample in the infrared-near infrared-visible-UV range of the spectrumSpectroscopic Devices such as LabSpec Pro Devices manufactured by Analytical Spectral Devices Inc., Boulder, Colorado.

In another aspect of the identification, the initial set and the first and second (and optionally third, fourth, etc.) sets of modified optical properties can comprise at least one property exhibiting an optically anisotropic or optically isotropic state of the liquid crystalline polymer composition. An example of a corresponding property is the reflection of circularly polarized light. In this regard, see, for example, the explanations provided in Y.Jiang et al, "Novel Pigment approach in Optical variable Security Inks incorporating Polarizing Liquid Crystal (CLC) Polymers," Optical Security and Counterfeit Deterference technical request IV, SPIE4677,2002, the entire disclosure of which is incorporated herein by reference.

Chiral liquid crystal precursor compositions useful for preparing the indicia of the present invention and which can be applied (e.g., deposited) on at least a portion of at least one surface of a substrate (in preferred embodiments, on at least a portion of a first modifying agent provided on at least one surface of a substrate) preferably comprise a mixture of: (i) one or more nematic compounds a and (ii) one or more cholesteric (i.e. chiral dopant) compounds B (including cholesterol) capable of giving rise to a cholesteric state of the composition. The pitch of the cholesteric state that can be achieved depends on the relative ratio of nematic to cholesteric compounds and the helical kink force of the cholesteric compounds. Typically, the (total) concentration of the one or more nematic compounds a in the chiral liquid crystal precursor composition used in the present invention is about 4 to about 50 times the (total) concentration of the one or more cholesteric compounds B. Generally, chiral liquid crystal precursor compositions having a high concentration of cholesteric compounds are not desirable (although possible in many cases) because one or more cholesteric compounds tend to crystallize, thereby making it impossible to obtain the desired liquid crystal state having particular optical properties.

Nematic compounds a suitable for use in chiral liquid crystal precursor compositions are known in the art; when used alone (without the cholesteric compounds), they place themselves in a state characterized by their birefringence. Non-limiting examples of nematic compounds A suitable for use in the present invention are described, for example, in WO93/22397, WO95/22586, EP-B-0847432, U.S. Pat. No.6,589,445, US2007/0224341A1 and JP 2009-300662A. The entire contents of these documents are incorporated herein by reference.

One preferred class of nematic compounds for use in the present invention comprises one or more (e.g. 1, 2 or 3) polymerizable groups per molecule which are the same or different from each other. Examples of polymerizable groups include groups capable of participating in free radical polymerization, and in particular groups comprising carbon-carbon double or triple bonds, such as acrylate moieties, vinyl moieties, or acetylene moieties. Acrylate moieties are particularly preferred as the polymerizable group.

The nematic compounds for use in the present invention may further comprise one or more (e.g. 1, 2,3, 4, 5 or 6) optionally substituted aromatic groups, preferably phenyl groups. Examples of optional substituents for the aromatic group include those described herein as examples of substituents on the phenyl ring of chiral dopant compounds of formula (I), e.g., (C)₁-C₆) Alkyl and/or (C)₁-C₆) An alkoxy group.

Examples of groups that may optionally be present in the nematic compound a to link the polymerizable group and the aryl group (e.g. phenyl) include those exemplified herein with respect to chiral dopant compounds B of formula (I), including those of formula (IA) and formula (IB) described below. For example, the nematic compound A may comprise one or more of A as described above in relation to formula (I) (and formulae (IA) and (IB))₁And A₂The meanings of (a) to (b) describe the radicals of the formulae (i) to (iii) which are generally bonded to optionally substituted phenyl. Specific non-limiting examples of nematic compounds suitable for use in the present invention include:

2-methoxybenzene-1, 4-diylbis [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) benzoate ];

4- { [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) benzoyl ] oxy } -2-methoxyphenyl 4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -2-methylbenzoate;

2-methoxybenzene-1, 4-diylbis [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -2-methyl-benzoate ];

2-methylbenzene-1, 4-diylbis [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -2-methyl-benzoate ];

4- { [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) benzoyl ] oxy } -2-methylphenyl 4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3-methoxybenzoate;

2-methylbenzene-1, 4-diylbis [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) benzoate ];

2-methylbenzene-1, 4-diylbis [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3-methoxy-benzoate ];

4- { [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3-methoxybenzoyl ] oxy } -2-methylphenyl 4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3, 5-dimethoxybenzoate;

2-methylbenzene-1, 4-diylbis [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3, 5-dimethoxy-benzoate ]; and

2-methoxybenzene-1, 4-diylbis [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3, 5-di-methoxy-benzoate ]; and

4- { [4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3-methoxybenzoyl ] oxy } -2-methoxyphenyl 4- ({ [4- (acryloyloxy) butoxy ] carbonyl } oxy) -3, 5-dimethoxybenzoate;

4- ({4- [4- (acryloyloxy) butoxy ] benzoyl } oxy) -3-methylphenyl 4- [4- (acryloyloxy) butoxy ] -2-methylbenzoate;

4- ({4- [4- (acryloyloxy) butoxy ] benzoyl } oxy) -3-methylphenyl 4- [4- (acryloyloxy) butoxy ] -3-methylbenzoate;

2-methylbenzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -2-methylbenzoate };

4- ({4- [4- (acryloyloxy) butoxy ] -2-methylbenzoyl } oxy) -3-methylphenyl 4- [4- (acryloyloxy) -butoxy ] -2, 5-dimethylbenzoate;

2-methylbenzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -2, 5-dimethylbenzoate } 2-methylbenzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] benzoate };

4- ({4- [4- (acryloyloxy) butoxy ] -3, 5-dimethylbenzoyl } oxy) -3-methylphenyl 4- [4- (acryloyloxy) butoxy ] -2, 5-dimethylbenzoate;

2-methylbenzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -3, 5-dimethylbenzoate };

2-methoxybenzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -3, 5-dimethylbenzoate };

4- ({4- [4- (acryloyloxy) butoxy ] -3-methylbenzoyl } oxy) -2-methoxyphenyl 4- [4- (acryloyloxy) -butoxy ] -3, 5-dimethylbenzoate;

2-methoxybenz-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -3-methylbenzoate };

4- ({4- [4- (acryloyloxy) butoxy ] benzoyl } oxy) -3-methoxyphenyl 4- [4- (acryloyloxy) -butoxy ] -3-methylbenzoate;

4- ({4- [4- (acryloyloxy) butoxy ] benzoyl } oxy) -3-methoxyphenyl 4- [4- (acryloyloxy) -butoxy ] -2, 5-dimethylbenzoate;

2-methoxybenz-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -2-methoxybenzoate };

2-methoxybenz-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -3, 5-dimethoxybenzoate };

2-methoxybenz-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -3-methoxybenzoate };

2-ethoxybenzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] benzoate };

2-ethoxybenzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -2-methylbenzoate };

2- (prop-2-yloxy) benzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] benzoate };

4- ({4- [4- (acryloyloxy) butoxy ] benzoyl } oxy) -2- (prop-2-yloxy) phenyl 4- [4- (acryloyloxy) butoxy ] -2-methylbenzoate;

2- (prop-2-yloxy) benzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -2-methylbenzoate };

2- (prop-2-yloxy) benzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -2, 5-dimethyl-benzoate };

2- (prop-2-yloxy) benzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -3, 5-dimethyl-benzoate }; and

2- (prop-2-yloxy) benzene-1, 4-diylbis {4- [4- (acryloyloxy) butoxy ] -3, 5-dimethoxy-benzoate }.

The one or more cholesteric (i.e., chiral dopant) compounds B for use in the present invention preferably comprise at least one polymerizable group.

As noted above, suitable examples of one or more chiral dopant compounds B include those of formula (I):

wherein:

R₁、R₂、R₃、R₄、R₅、R₆、R₇and R₈Each independently represents C₁-C₆Alkyl and C₁-C₆An alkoxy group;

A₁and A₂Each independently represents a group of formulae (i) - (iii):

(i)-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(ii)-C(O)-D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(iii)-C(O)-D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

D₁a group represented by the formula:

D₂a group represented by the formula:

m, n, o, p, q, r, s and t each independently represent 0, 1 or 2;

y represents 0, 1, 2,3, 4, 5 or 6;

if y is equal to 0, then z is equal to 0, and if y is equal to 1-6, then z is equal to 1.

In one aspect, the one or more chiral dopant compounds B may comprise one or more isomannide derivatives of formula (IA):

wherein:

R₁、R₂、R₃、R₄、R₅、R₆、R₇and R₈Each independently represents C₁-C₆Alkyl and C₁-C₆An alkoxy group;

A₁and A₂Each independently represents a group of formulae (i) - (iii):

(i)-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(ii)-C(O)-D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(iii)-C(O)-D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

D₁a group represented by the formula:

D₂a group represented by the formula:

m, n, o, p, q, r, s and t each independently represent 0, 1 or 2;

y represents 0, 1, 2,3, 4, 5 or 6;

if y is equal to 0, then z is equal to 0, and if y is equal to 1-6, then z is equal to 1.

In one embodiment of the compounds of formula (IA) (and compounds of formula (I)), R₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkyl group. In alternative embodiments, R in formula (IA) (and in formula (I)) is₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkoxy group.

In another embodiment of the compounds of formula (I) and formula (IA), A₁And A₂Each independently of the other, of the formula- [ (CH)₂)_y-O]_z-C(O)-CH=CH₂A group of (a); r₁、R₂、R₃And R₄Each independently represents C₁-C₆An alkyl group; and m, n, o and p each independently represent 0, 1 or 2. In yet another embodiment, A in formula (I) and formula (IA)₁And A₂Each independently of the other, of the formula- [ (CH)₂)_y-O]_z-C(O)-CH=CH₂A group of (a); r₁、R₂、R₃And R₄Each independently represents C₁-C₆An alkoxy group; and m, n, o and p each independently represent 0, 1 or 2.

In another embodiment of the compounds of formula (IA) (and formula (I)), A1 and A2 each independently represent a compound of formula-C (O) -D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂And/or of the formula-C (O) -D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂A group of (a); and R is₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkyl group. In alternative embodiments, A1 and A2 in formula (IA) (and in formula (I)) each independently represent a compound of formula-C (O) -D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂And/or a group of the formula-C (O) -D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂A group of (a); and R is₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkoxy group.

In another aspect, the one or more chiral dopant compounds B may comprise one or more isosorbide derivatives represented by formula (IB):

wherein:

R₁、R₂、R₃、R₄、R₅、R₆、R₇and R₈Each independently represents C₁-C₆Alkyl and C₁-C₆An alkoxy group;

A₁and A₂Each independently represents a group of formulae (i) - (iii):

(i)-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(ii)-C(O)-D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(iii)-C(O)-D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

D₁a group represented by the formula:

D₂a group represented by the formula:

m, n, o, p, q, r, s and t each independently represent 0, 1 or 2;

y represents 0, 1, 2,3, 4, 5 or 6;

if y is equal to 0, then z is equal to 0, and if y is equal to 1-6, then z is equal to 1.

In one embodiment of the compounds of formula (IB), R₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkyl group. In alternative embodiments, R in formula (IB)₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkoxy group.

In another embodiment of the compounds of formula (IB), A₁And A₂Each independently of the other, of the formula- [ (CH)₂)_y-O]_z-C(O)-CH=CH₂Group of (A), R₁、R₂、R₃And R₄Each independently represents C₁-C₆An alkyl group; and m, n, o and p each independently represent 0, 1 or 2. In yet another embodiment, A in formula (IB)₁And A₂Each independently of the other, of the formula- [ (CH)₂)_y-O]_z-C(O)-CH=CH₂A group of (a); r₁、R₂、R₃And R₄Each independently represents C₁-C₆An alkoxy group; and m, n, o and p each independently represent 0, 1 or 2.

In another embodiment of the compounds of formula (IB), A₁And A₂Each independently of the other, of the formula-C (O) -D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂And/or of the formula-C (O) -D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂A group of (a); and R is₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkyl group. In alternative embodiments, A in formula (IB)₁And A₂Each independently of the other, of the formula-C (O) -D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂And/or a group of the formula-C (O) -D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂A group of (a); and R is₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈Each independently represents C₁-C₆An alkoxy group.

In a preferred embodiment, R in the formulae (I), (IA) and (IB)₁、R₂、R₃、R₄、R₅、R₆、R₇And R₈The alkyl and alkoxy groups of (a) may contain 3,4, 6 or 7 carbon atoms, in particular 4 or 6 carbon atoms.

Examples of alkyl groups containing 3 or 4 carbon atoms include isopropyl and butyl. Examples of the alkyl group having 6 or 7 carbon atoms include hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2-dimethylpentyl group and 2, 3-dimethylpentyl group.

Examples of the alkoxy group having 3 or 4 carbon atoms include isopropoxy, but-1-oxy, but-2-oxy and tert-butoxy. Examples of the alkoxy group having 6 or 7 carbon atoms include hex-1-oxy, hex-2-oxy, hex-3-oxy, 2-methylpent-1-oxy, 2-methylpent-2-oxy, 2-methylpent-3-oxy, 2-methylpent-4-oxy, 4-methylpent-1-oxy, 3-methylpent-2-oxy, 3-methylpent-3-oxy, 2-dimethylpent-1-oxy, 2-dimethylpent-3-oxy, 2-dimethylpent-4-oxy, 4-dimethylpent-1-oxy, 2-dimethylpent-4-oxy, 2-dimethylpent-1-oxy, 2-dimethylpent, 2, 3-dimethylpent-1-oxy, 2, 3-dimethylpent-2-oxy, 2, 3-dimethylpent-3-oxy, 2, 3-dimethylpent-4-oxy and 3, 4-dimethylpent-1-oxy.

Non-limiting specific examples of chiral dopant compounds B of formula (I) for use in the present invention include: (3R,3aR,6R,6aR) -hexahydrofuro [3,2-b ] furan-3, 6-diylbis (4- (4- (acryloyloxy) -3-methoxybenzoyl-oxy) -3-methoxybenzoate);

(3R,3aR,6R,6aR) -6- (4- (4- (acryloyloxy) -3-methoxybenzoyloxy) -hexahydrofuro [3,2-b ] -furan-3-yl 4- (4- (acryloyloxy) benzoyloxy) -3-methoxy-benzoate;

(3R,3aR,6R,6aR) -hexahydrofuro [3,2-b ] furan-3, 6-diylbis (4- (4 (acryloyloxy) benzoyloxy) -benzoate);

(3R,3aR,6R,6aR) -hexahydrofuro [3,2-b ] furan-3, 6-diylbis (4- (4- (acryloyloxy) butoxy) -benzoate);

(3R,3aR,6R,6aR) -hexahydrofuro [3,2-b ] furan-3, 6-diylbis (4- (acryloyloxy) -2-methyl-benzoate);

(3R,3aR,6S,6aR) -hexahydrofuro [3,2-b ] furan-3, 6-diylbis (4- (4- (acryloyloxy) benzoyloxy) -3-methoxybenzoate);

(3R,3aR,6R,6aR) -hexahydrofuro [3,2-b ] furan-3, 6-diylbis (4- (4- (acryloyloxy) -3-methoxy-benzoyloxy) benzoate);

(3R,3aR,6R,6aR) -hexahydrofuro [3,2-b ] furan-3, 6-diylbis (4- (4 (acryloyloxy) benzoyloxy) -3-methoxybenzoate);

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -benzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -2-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxy-5-methylbenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } benzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-mannitol; 2, 5-bis-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2, 5-dimethylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxy-5-methylbenzoyl ] oxy } -2-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -5-methoxy-2-methylbenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-ethoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-ethoxybenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-mannitol; 2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-ethoxy-5-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-ethoxybenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-ethoxy-5-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -5-ethoxy-2-methylbenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -3-ethoxybenzoyl ] oxy } benzoyl) -5-O- (4- { [4- (acryloyloxy) -2-methylbenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-ethoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -2-methylbenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-mannitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -benzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -2-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxy-5-methylbenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methylbenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-methoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } benzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2, 5-dimethylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-methoxybenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2-methoxy-5-methylbenzoyl ] oxy } -2-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -5-methoxy-2-methylbenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-ethoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-ethoxybenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-ethoxy-5-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -3-ethoxybenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) benzoyl ] oxy } -2-ethoxy-5-methylbenzoyl) -5-O- (4- { [4- (acryloyloxy) -5-ethoxy-2-methylbenzoyl ] oxy } benzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -3-ethoxybenzoyl ] oxy } benzoyl) -5-O- (4- { [4- (acryloyloxy) -2-methylbenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-ethoxybenzoyl) -5-O- (4- { [4- (acryloyloxy) -2-methylbenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2, 5-dimethylbenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-methoxybenzoyl ] oxy } -2-ethoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -2-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol;

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -3-methylbenzoyl) -1,4:3, 6-dianhydro-D-glucitol; and

2, 5-bis-O- (4- { [4- (acryloyloxy) -2-ethoxybenzoyl ] oxy } -3-methoxybenzoyl) -1,4:3, 6-dianhydro-D-glucitol.

The one or more chiral dopant compounds B are typically present in a total concentration of about 0.1 to about 30 weight percent, for example about 0.1 to about 25 percent or about 0.1 to about 20 weight percent, based on the total weight of the composition. For example, in the case of ink jet printing, best results are generally obtained at concentrations of from 3 to 10% by weight, for example from 5 to 8% by weight, based on the total weight of the composition. The one or more nematic compounds a are present in a concentration of about 30 to about 50% by weight, based on the total weight of the composition.

Another component of the chiral liquid crystal precursor composition for use in the present invention is a salt, especially in the case where the first modifier is capable of altering the position of the selective reflection band exhibited by a cured chiral liquid crystal precursor composition comprising a salt, especially a salt capable of altering the position of the selective reflection band exhibited by a cured chiral liquid crystal precursor composition (in the chiral liquid crystal state) as compared to the position of the selective reflection band exhibited by a cured composition without a salt. In this regard, reference may be made to the explanations in U.S. provisional patent application nos. 61/420,580 and 61/420,582 filed on 12/7/2010, the entire disclosures of which are expressly incorporated herein by reference. As regards the selective reflection bands exhibited by the chiral liquid crystal polymer composition, reference may be made, for example, to the explanations in US patent No.7,742,136 or US2010/0025641, the entire disclosures of which are expressly incorporated herein by reference.

The extent to which the position of the selective reflection band exhibited by a given cured chiral liquid crystal precursor composition can be shifted by the presence of a salt depends on various factors such as, inter alia, the cation of the salt, the anion of the salt, and the salt concentration per gram of dry extract. Generally, it is preferred that the salt is present in a given chiral liquid crystal precursor composition at a concentration at which the position of the selective reflection band exhibited by the cured chiral liquid crystal precursor composition is shifted by at least about 5nm, such as at least about 10nm, at least about 20nm, at least about 30nm, at least about 40nm, or at least about 50 nm. Suitable (total) salt concentrations are generally from about 0.01 to about 10 wt%, for example from about 0.1 to about 5 wt%, based on the solids content of the chiral liquid crystal precursor composition. Salt concentrations above the range are often difficult to achieve because of the limited solubility of the salt in the chiral liquid crystal precursor composition.

Non-limiting examples of suitable salts include salts comprising metal cations (main group metals, transition metals, lanthanides, and actinides). For example, the metal may be an alkali or alkaline earth metal such as Li, Na. Li salts are particularly preferred. Other non-limiting examples of suitable salts include quaternary ammonium salts such as tetraalkylammonium salts. Examples of suitable anions include "regular" ions, such as halides (e.g., fluorine, chlorine, bromine, iodine), perchlorate, nitrate, nitrite, sulfate, sulfonate, sulfite, carbonate, bicarbonate, cyanide, cyanate, and thiocyanate, and complex ions, such as tetrafluoroborate. Specific but non-limiting examples of suitable salts include lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium bromide, lithium chloride, tetrabutylammonium perchlorate, tetrabutylammonium chloride, tetrabutylammonium tetrafluoroborate, tetrabutylammonium bromide, sodium carbonate, sodium chloride, and sodium nitrate. Of course, mixtures of two or more salts (e.g., 2,3, 4, or more salts) can also be used. If two or more salts are present, they may or may not contain the same cation and/or anion. In another aspect, the at least one salt may comprise lithium perchlorate and/or lithium bromide.

Non-limiting examples of first modifiers useful in the present invention include materials and particularly resins capable of altering the position of the selective reflection band exhibited by a cured chiral liquid crystal precursor composition containing a salt capable of altering the position of the selective reflection band exhibited by a cured chiral liquid crystal precursor composition (in the chiral liquid crystal state) as compared to the position of the selective reflection band exhibited by a cured composition not having the salt. Such resins are hereinafter referred to as "modified resins". In this regard, reference is again made to the detailed explanations in U.S. provisional patent application nos. 61/420,580 and 61/420,582.

The modifying resin used as the first modifier in the present invention is typically placed between (and in direct contact with) the matrix and the chiral liquid crystal precursor composition. The modified resin used in the present invention is not particularly limited, provided that it is capable of altering to a significant extent at least one optical property exhibited by the cured chiral liquid crystal precursor composition on the substrate. In this regard, it is preferred that the modified resin is capable of changing at least the position of the selective reflection band, such as λ_maxShown, in particular, is capable of varying λ_maxAt least about 5nm, such as at least about 10nm, at least about 20nm, at least about 30nm, at least about 40nm, or at least about 50 nm. This ability depends on various factors, such as, inter alia, the components of the chiral liquid crystal precursor composition, such as the salts and chiral dopants contained therein, and in the modified resin (toAnd thus on the surface thereof) the presence (or absence) of functional groups.

Examples of the modified resin suitable for use as the first modifier in the present invention include those composed of one or more (e.g., 1, 2,3 or 4) polymerizable monomers containing one or more (e.g., 1, 2 or 3) hetero atoms selected from, for example, O, N or S. In this regard, it is to be understood that the polymerizable monomers are not limited to those that can be polymerized by free radical polymerization. Rather, these monomers also include monomers which can be polymerized, for example, by cationic and/or anionic polymerization and/or by polycondensation. Thus, non-limiting examples of resins suitable for use in the present invention include organic resins such as polyacrylates, polymethacrylates, polyvinyl ethers, polyvinyl esters, polyesters, polyethers, polyamides, polyurethanes, polycarbonates, polysulfones, phenolic resins, epoxy resins, and mixed versions of these resins. Hybrid inorganic/organic resins such as siloxanes (e.g., polyorganosiloxanes) are also suitable. One particular class of resins useful in the present invention are aqueous resins such as polyamide resins (e.g., CAS No175893-71-7, CAS No303013-12-9, CAS No393802-62-5, CAS No122380-38-5, CAS No 9003-39-8).

Non-limiting examples of modified resins for use as the first modifier in the present invention further include those composed of one or more monomers selected from the group consisting of polyether acrylates, modified polyether acrylates (e.g., amine-modified polyether acrylates), polyester acrylates, modified polyester acrylates (e.g., amine-modified polyester acrylates), hexafunctional polyester acrylates, tetrafunctional polyester acrylates, aromatic difunctional urethane acrylates, aliphatic trifunctional urethane acrylates, aliphatic hexafunctional urethane acrylates, urethane monoacrylates, aliphatic diacrylates, bisphenol a epoxyacrylates, modified bisphenol a epoxyacrylates, modified epoxyacrylates (e.g., fatty acid-modified epoxyacrylates), Acrylic oligomers, hydrocarbon acrylate oligomers, ethoxylated phenol acrylates, polyethylene glycol diacrylates, propoxylated neopentyl glycol diacrylates, diacrylated bisphenol a derivatives, dipropylene glycol diacrylates, hexanediol diacrylates, tripropylene glycol diacrylates, polyether tetraacrylates, di-trimethylolpropane tetraacrylates, dipentaerythritol hexaacrylates, mixtures of pentaerythritol tri-and tetraacrylates, dipropylene glycol diacrylates, hexanediol diacrylates, ethoxylated trimethylolpropane triacrylates and tripropylene glycol diacrylates (optionally in combination with one or more monomers other than the above monomers).

It is to be understood that the modified resin used in the present invention is not necessarily fully cured (polymerized) or dried before it is contacted with the chiral liquid crystal precursor composition, provided that it is able to withstand the components and especially solvents that may (and typically will) be present in the (uncured) chiral liquid crystal precursor composition (e.g. the modified resin is thus not optionally dissolved to a significant extent). The curing of the only partially cured modified resin may for example be done together with the curing of the chiral liquid crystal precursor (e.g. by UV radiation).

One of the advantages of the present invention over the prior art (as described for example in WO2001/024106, WO2008/127950, the entire disclosure of which is incorporated herein by reference) is the ability to produce perfect recordings without the use of masking techniques. Perfect recording means that a single layer of liquid crystal polymer can be present in very few steps and/or process steps, where there are two or more zones with different color shifting properties and/or different selective reflection band positions at the same time, and these zones can be perfectly adjacent without gaps or overlaps between them. This advantage derives from the fact that: the chiral liquid crystal precursor composition is applied in one step and its properties are locally modified by the modifying resin. To achieve similar results without the present method, the skilled person must apply and cure two or more chiral liquid crystal precursor compositions in successive steps with too high precision so that they cover adjacent areas without gaps or overlaps. The method allows the direct production of labels, logos, codes, bar codes, patterns, data matrices, etc., which simultaneously contain different information and/or colors. The possibilities offered by the present method include the use of a mixture of modified resins (e.g. a mixture of 2,3, 4 or more modified resins) in the form of a cured physical mixture of two or more modified resins and in the form of two or more different modified resins (respectively) present at different locations on the surface of the substrate.

Alternatively or additionally, two or more different chiral liquid crystal precursor compositions may also be used, which differ and/or differ in the concentration of the salts contained therein by the different salts contained therein. This alone yields a large number of possible combinations of chiral liquid crystal precursor compositions with modified resins that may be present on a single substrate surface. This large number of possible combinations allows in particular the possibility of producing special codes and/or logos which are difficult to counterfeit, since anyone who wants to reproduce it must know the exact composition of the chiral liquid crystal precursor composition, the type, amount and concentration of the salt contained therein and the nature of the modified resin. The large number of possible combinations can be further (significantly) enhanced by using more than one second modifier in combination with one or more (or each) chiral liquid crystal precursor composition and the first modifier. The incorporation of other special security elements such as near infrared, infrared and/or UV security elements, magnetic particles, pigments of at least two different particle size ranges and pigments such as "normal" particle size and nano-sized pigments (known only to the identified manufacturers) into the chiral liquid crystal precursor composition and/or the modified resin makes counterfeiting even more difficult. Thus, the present invention also contemplates and includes the use of chiral liquid crystal precursor compositions and modified resins that contain other specific security elements.

It should also be understood that the present invention is not limited to the visible region of the electromagnetic spectrum. For example, the modifying resin used in the present invention may shift all or a portion of the selective reflection band exhibited by the cured chiral liquid crystal precursor composition from the IR region to the visible region, or from the visible region to the UV region, or from the IR region to the UV region, or vice versa, e.g., from the UV region to the visible region.

The chiral liquid crystal precursor composition and the composition for preparing the modified resin or other first modifier may be applied to the surface of the substrate or article by any suitable method, such as spraying, knife coating, roll coating, screen coating, curtain coating, gravure printing, flexographic printing, offset printing, dry offset printing, letterpress printing, screen printing, pad printing, and ink jet printing (e.g., continuous ink jet printing, drop-on-demand ink-jet printing), and valve-jet printing). In one embodiment of the present invention, the application (e.g., deposition) of the composition for preparing the layer or pattern and/or the composition for preparing the modified resin is carried out with printing techniques such as ink jet printing (continuous, drop on demand, etc.), flexographic printing, pad printing, rotogravure printing, screen printing, and the like. Of course, other printing techniques known to those skilled in the art of printing may also be used. In a preferred embodiment of the invention, the modified resin is applied and the chiral liquid crystal precursor composition is applied using flexography. In another preferred embodiment of the invention, the modified resin is applied and the chiral liquid crystal precursor composition is applied using ink jet printing techniques. It is also contemplated that two different techniques may be used to apply the modified resin and the chiral liquid crystal precursor composition, respectively. Industrial inkjet printers that are commonly used for numbering, coding and marking applications on conditioning lines and printers are particularly suitable. Preferred ink jet printers include single nozzle continuous ink jet printers (also known as raster or multi level deflected printers) and drop on demand ink jet printers, particularly valve jet printers. The liquid crystalline polymer composition applied according to the application techniques described above typically has a thickness after curing of at least about 1 μm, such as at least about 2 μm, or at least about 3 μm or at least about 4 μm, and typically no greater than about 20 μm, such as no greater than about 15 μm, no greater than about 10 μm, or no greater than about 6 μm. The thickness of the modifying resin applied according to the application techniques described above after curing is typically at least about 1 μm, for example at least about 2 μm or at least about 3 μm, or at least about 5 μm, but is typically no greater than about 10 μm.

In particular, if the composition used in the present invention (i.e. the composition for preparing the chiral liquid crystal precursor or the composition for preparing the modified resin) is applied by the above-mentioned printing technique, the composition usually comprises a solvent to adjust its viscosity to a value suitable for the application (printing) technique used. Typical viscosity values for flexographic printing of the compositions used in the present invention are from about 10 to about 120 seconds, preferably from 10 to 100 seconds, more preferably from 10 to 60 seconds, even more preferably from 10 to 40 seconds, for example as measured using DIN4 cup at 25 ℃. Suitable solvents are known to those skilled in the art. Non-limiting examples thereof include low viscosity, slightly polar and aprotic organic solvents such as Methyl Ethyl Ketone (MEK), acetone, cyclohexanone, ethyl acetate, ethyl 3-ethoxypropionate, and mixtures of two or more thereof.

In addition, in particular if the composition used in the present invention (i.e. the composition for preparing the chiral liquid crystal precursor or the composition for preparing the modified resin) is applied by (continuous) ink-jet printing, the composition usually also comprises at least one conductive agent known to the person skilled in the art.

If the chiral liquid crystal precursor composition used in the present invention and/or the composition used for preparing the modified resin is cured/polymerized by UV radiation, the composition further comprises at least one photoinitiator. Non-limiting examples of many suitable photoinitiators include alpha-hydroxy ketones, such as 1-hydroxy-cyclohexyl-phenyl-ketone, and mixtures of 1-hydroxy-cyclohexyl-phenyl-ketone with one or more of the following (e.g., about 1: 1): benzophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl ] -2-methyl-1-propanone; phenyl glyoxylates, such as methylbenzoyl formate and mixtures of oxy-phenyl-acetic acid 2- [ 2-oxo-2-phenyl-acetoxy-ethoxy ] -ethyl ester and oxy-phenyl-acetic acid 2- [ 2-hydroxy-ethoxy ] -ethyl ester; benzyl dimethyl acetal acetophenones, such as α, α -dimethoxy- α -phenylacetophenone; α -aminoketones such as 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl ] -1-butanone and 2-methyl-1- [4- (methylthio) phenyl ] -2- (4-morpholinyl) -1-propanone; with the above-described photoinitiators, the composition may further comprise co-initiators, such as phosphine oxides and phosphine oxide derivatives, for example diphenyl (2,4, 6-trimethylbenzoyl) -phosphine oxide; phenylbis (2,4, 6-trimethylbenzoyl) from Ciba; and thioxanthone derivatives such as Speedcure ITX (CAS142770-42-1), Speedcure DETX (CAS82799-44-8), Speedcure CPTX (CAS5495-84-1-2 or CAS83846-86-O) supplied by Lambson.

If the composition used in the present invention (i.e., the composition for preparing the chiral liquid crystal precursor or the composition for preparing the modified resin) is cured by a method other than irradiation with UV light, for example, by high-energy particles (e.g., electron beam), X-rays, gamma-rays, etc., the use of a photoinitiator can of course be omitted.

It is also possible or even desirable to thermally cure, in particular, the composition used to prepare the modified resin. In this case, the composition generally contains at least one thermal polymerization initiator, such as a peroxide or an azo compound. Other examples of thermal polymerization initiators are well known to those skilled in the art.

The chiral liquid crystal precursor compositions and compositions for providing modified resins for use in the present invention may also comprise a variety of other optional components suitable and/or desirable for achieving the particular desired properties of the composition, and generally may include any component/material that does not adversely affect the desired properties of the composition to any significant extent. Non-limiting examples of such optional components are resins, silane compounds, adhesion promoters, sensitizers for photoinitiators (if present), and the like. For example, the chiral liquid crystal precursor composition for use in the present invention may comprise, inter alia, one or more silane compounds. Non-limiting examples of suitable silane compounds include optionally polymerizable silanes, such as of the formula R₁R₂R₃-Si-R₄Wherein R is₁、R₂And R₃Independently represent alkoxy and alkoxyalkoxy having a total of from 1 to about 6 carbon atoms, and R₄Represents a vinyl group, an allyl group, or (C)_1-10) Alkyl, (meth) acryloyloxy (C)_1-6) Alkyl and glycidoxy (C)_1-6) Alkyl radicals, e.g. from EvonikVinyl triethoxysilane and vinyl trimethoxy siliconAlkyl, vinyltris (2-methoxyethoxy) silane, 3-methacryloxypropyl-trimethoxysilane, octyltriethoxysilane, and 3-glycidoxypropyltriethoxysilane.

The concentration of the one or more silane compounds in the chiral liquid crystal precursor composition, if present, is typically from about 0.5 to about 5 weight percent based on the total weight of the composition.

To enhance the security of the marking of the present invention, the composition used in the present invention for the preparation of the modified resin and/or the composition used in the preparation of the chiral liquid crystal precursor may further comprise one or more pigments and/or dyes absorbing in the visible or invisible region of the electromagnetic spectrum, and/or one or more luminescent pigments and/or dyes, and/or one or more magnetic particles and/or one or more pigments of different particle size ranges (e.g. "normal" particle size and nanoscale pigments). Non-limiting examples of suitable pigments and/or dyes that absorb in the visible or invisible region of the electromagnetic spectrum include phthalocyanine derivatives. Non-limiting examples of suitable luminescent pigments and/or dyes include lanthanide derivatives. Non-limiting examples of suitable magnetic pigments include particles of transition metal oxides such as iron and chromium oxides. The presence of pigments and/or dyes enhances and strengthens the security of the identification against counterfeiting.

After the chiral liquid crystal precursor composition is applied in a layer or pattern on the surface of the one or more first areas of the substrate or article bearing the one or more first modifiers, the composition can produce a chiral liquid crystal state having an initial set of optical properties (and a first set of modified optical properties in the one or more first areas). To this end, the chiral liquid crystal precursor composition is heated, whereby the solvent contained in the composition, if present, evaporates and promotion of the desired chiral liquid crystal state occurs. The temperature used to evaporate the solvent and promote the formation of the liquid crystal state depends on the components of the chiral liquid crystal precursor composition and in many cases is from about 55 to about 150 c, for example from about 55 to about 100 c, preferably from about 60 to about 100 c. Examples of suitable heating sources include conventional heating means such as hot tables, ovens, hot air streams and in particular radiation sources such as IR lamps. The required heating time depends on several factors, such as the components of the chiral liquid crystal precursor composition, the type of heating device and the intensity of heating (energy output of the heating device). In many cases, a heating time of about 0.1 seconds, about 0.5 seconds, or about 1 to about 30 seconds, such as not greater than about 20 seconds, not greater than about 10 seconds, or not greater than about 5 seconds, is sufficient.

After the chiral liquid crystal state is formed, a second modifier may be applied to one or more of the second areas of the composition in the initial chiral liquid crystal state (optionally also to one or more of its one or more first areas or portions). The second modifier is capable of changing the initial chiral liquid crystal state (optionally upon heating, depending on the type of second modifier) and the first modified chiral liquid crystal state (if applied to the first area or a portion thereof). The second modifier may be applied while the chiral liquid crystal precursor composition is still in a heated state (e.g., immediately after the heating operation is complete) or may be applied after the chiral liquid crystal precursor composition has cooled to at least some extent (e.g., at substantially room temperature). If desired, the cooling of the chiral liquid crystal precursor composition can be accelerated by methods known to those skilled in the art, for example by blowing ambient air over the previously heated composition. Applying a second modifier to the chiral liquid crystal precursor composition in the cooled state can improve the resolution of the marking. On the other hand, if the entire process for preparing the marking is carried out in as simple and rapid a manner as possible, it may be desirable to apply the second modifier immediately after the heating operation is completed.

The second modifier used in the present invention does not extract any compounds that form the initial or first modified chiral liquid crystal state, nor does it alter the chemical structure of these compounds to any significant extent, preferably not at all. Without wishing to be bound by any theory, it is speculated that at least some of the second modifiers that may be used induce a very local and controllable recombination of the chiral liquid crystal state.

In the present invention identification, depending on its nature, the second modifier changes the initial (unmodified) chiral liquid crystal state (and also the first modified chiral liquid crystal state if applied in one or a portion of one or more of the first areas) from a (predominantly or essentially) anisotropic state characterized by specific optical properties to:

(i) (predominantly or substantially) isotropic liquid crystalline state in which the colourshifting properties of the chiral liquid crystalline state are substantially absent and/or no longer detectable to the naked eye (as provided, for example, by the substance I modifier described below), or

(ii) (second) modified chiral liquid crystal state exhibiting a second set of modified optical properties having at least one optical property different from the corresponding optical property of the initial chiral liquid crystal state (as provided by, e.g., a substance II or substance III modifier described below).

The second modifier can be, for example, a "species I" modifier. The substance I modifier generally comprises one or more aprotic organic compounds that are liquid at room temperature and preferably have a relatively high dipole moment and a relatively high dielectric constant. Non-limiting examples thereof include ketones having 3 to about 6 carbon atoms, alkyl esters and dialkylamides of carboxylic acids containing a total of 2 to about 6 carbon atoms, dialkyl sulfoxides containing a total of 2 to about 4 carbon atoms, and optionally substituted (e.g., alkyl substituted) nitrobenzenes such as dimethyl ketone, methyl ethyl ketone, ethyl acetate, dimethyl formamide, dimethyl sulfoxide, nitrobenzene, and mixtures of two or more thereof. Preferred compounds for or as modifiers of substance I include acetone, methyl ethyl ketone and ethyl acetate.

The material I modifier used in the present invention may further comprise one or more resins to adjust its viscosity. Of course, the resin must be the same as the application (e.g., printing) technique to be used. Non-limiting examples of resins that may be suitable, depending on the particular circumstances, include polyester resins, such as from EvonikL1203、L205、L206、L208、L210、L411、L651、L658、L850、L912、L952、LH530、LH538、LH727、LH744、LH773、LH775、LH818、LH820、LH822、LH912、LH952、LH530、LH538, LH727, LH744, LH773, LH775, LH818, LH820, LH822, LH823, LH826, LH828, LH830, LH831, LH832, LH833, LH838, LH898, LH908, LS436, LS615, P1500, S1218, S1227, S1247, S1249, S1252, S1272, S1401, S1402, S1426, S1450, S1510, S1606, S1611, S243, S320, S341, S361, S394, and S EP 1408. Other suitable resins known to those skilled in the art may also be used. In a preferred embodiment, the one or more resins are selected from the group consisting of those from EvonikL1203, L205, L206, L208, L210, L411, L651, L658, L850, L912, L952, LH530, LH538, LH727, LH 744. Typical concentrations of the one or more resins are from about 3 to about 15 weight percent based on the total weight of the material I modifier.

The material I modifier may further comprise one or more conductive agents, such as a salt that imparts sufficient conductivity to the material I modifier to allow it to be used in combination with a printer, such as a continuous ink jet printer. Examples of suitable conductive agents include those described above as examples of conductive agents for use in the chiral liquid crystal precursor compositions of the present invention, such as tetrabutylammonium nitrate, tetrabutylammonium perchlorate, tetrabutylammonium hexafluorophosphate, potassium thiocyanate, lithium perchlorate, and other conductive agents known in the art.

When the substance I modifier comprises a solvent or solvent mixture, the initial chiral liquid crystal state (and, if applicable, the first modified chiral liquid crystal state) changes locally (in one or more second areas) from a (predominantly or substantially) optically anisotropic state to a (predominantly or substantially) optically isotropic state upon evaporation of the solvent.

The second modifier may further be a "substance II" modifier, i.e. a (second) chiral liquid crystal precursor composition. The chiral liquid crystal precursor composition applied to the one or more second areas of the chiral liquid precursor composition is the same as or different from the base chiral liquid precursor composition to be modified. In addition, everything that has been described above with respect to the base chiral liquid precursor composition (e.g., components, application method, etc.) applies equally and without exception to the chiral liquid precursor composition used as the second modifier (substance II modifier). For example, as in the case of the base chiral liquid crystal precursor composition, the one or more chiral dopant compounds B are typically present in the material II modifier at a total concentration of about 0.1 to about 30 weight percent, such as about 0.1 to about 25 percent, or about 0.1 to about 20 weight percent, based on the total weight of the material II modifier. Furthermore, the one or more nematic compounds A are generally present in the substance II modifier in a concentration of from about 30 to about 50% by weight, based on the total weight of the substance II modifier.

If the substance II modifier is different from the base chiral liquid crystal precursor composition to be modified, one or more of the differences may relate to, for example, one or more of the compounds A and B and/or as above "the substance I modifier may further comprise one or more conductive agents … … other conductive agents known in the art" salts present in these compositions as described in the opening paragraph, and/or the concentration of one or more of these compounds. For example, the difference or the only difference between these compositions may be that one or more (or all) chiral dopant compounds B are present in the substance II modifier at a concentration different from the corresponding concentration in the base composition. Additionally, the difference or the only difference in these compositions may be that one or more chiral dopant compounds B in the base composition have formula (I) and/or a related formula above, and that at least one of the one or more chiral dopant compounds B in the substance II modifier is different from formula (I) and/or a related formula. For example, at least one of the one or more chiral dopant compounds B in the substance II modifier may be an isosorbide or isomannide derivative as described, for example, in EP-B-0847432, GB-A-2330139, and U.S. Pat. No.6,589,445, the entire disclosure of which is incorporated herein by reference.

It is to be understood here that if the substance II modifier is different from the base chiral liquid crystal precursor composition, it may also be applied to one or more areas on the surface of the substrate or article without the base composition (but optionally with the first modifier). In this way, it is possible to create a further variant of the marking according to the invention, namely one or more areas of the substance II modifier having a chiral liquid-crystalline state (obtained after renewed heating) and/or one or more areas of the substance II modifier having its chiral liquid-crystalline state (formed after heating) modified by the first modifier.

After applying (e.g., depositing) the substance II modifier onto one or more second areas of the base chiral liquid crystal precursor composition in the chiral liquid crystal state, the system produces a second modified chiral liquid crystal state to yield a second set of modified optical properties in the one or more second areas. To this end, at least the second area or areas are heated, whereby the solvent contained in the substance II modifier, if present, is evaporated and promotion of the desired second modified chiral liquid crystal state in the second area or areas takes place. The temperature used to evaporate the solvent and promote the formation of the second modified chiral liquid crystal state depends on the components of the material II modifier, and in many cases is from about 55 to about 150 ℃, e.g., from about 55 to about 100 ℃, preferably from about 60 to about 100 ℃. Examples of suitable heating sources include conventional heating methods and in particular radiation sources such as IR lamps.

It is to be understood here that in case a substance II modifier, i.e. a (second) chiral liquid crystal precursor composition, is used as second modifier, the simple overlap of the inventive identification with two chiral nematic liquid crystal layers is different or comparable. This constitutes a significant difference compared to the prior art. In particular, when the base chiral liquid crystal precursor composition is deposited on a substrate and an initial chiral liquid crystal state is produced, the state is characterized by a pitch p 1. Likewise, when a second chiral liquid crystal precursor composition (species II modifier) is deposited on one or more second areas of the base composition and produces a second modified chiral liquid crystal state, the second modified state is characterized by a pitch p2 (which may be the same as or different from p 1). In this regard, in the process of the present invention, the product obtained after curing/polymerization is not a superposition of a first chiral liquid crystal state having a pitch p1 and a second chiral liquid crystal state having a pitch p 2. Instead, the area with the first chiral liquid crystal precursor composition, once the second modified chiral liquid crystal state is produced, has p 2' which differs from p1 and p2 but depends slightly on the properties of p 1.

In yet another embodiment of the present invention, the second modifier may be a "species III" modifier, i.e., a chiral dopant composition. The chiral dopant composition preferably comprises one or more (e.g. 1, 2,3 or 4) chiral dopant compounds C of formula (I) and/or related formulae as described above. In a more preferred embodiment, the chiral dopant composition comprises at least one chiral dopant compound C and at least one other chiral dopant compound D different from the compounds of formula (I) and related formulae. The at least one chiral dopant compound D may, for example, be selected from isosorbide and isomannide, which are disclosed, for example, in EP-B-0847432, GB-a-2330139 and U.S. Pat. No.6,589,445, the entire disclosures of which are incorporated herein by reference.

As chiral dopant compound C, which is preferably present in the chiral dopant composition (substance III modifier), the above-mentioned chiral dopant compound B can be used, for example. Thus, everything described above with respect to compound B is the same and applies without exception to compound C. Furthermore, it is to be understood that the chiral dopant compound C present in (or only in) the chiral dopant composition may be the same as the chiral dopant compound B present in (or only in) the chiral liquid crystal precursor composition.

The chiral dopant composition typically comprises a total concentration of one or more chiral dopant compounds of about 0.1 to about 30 weight percent, for example about 0.1 to about 25%, or about 0.1 to about 20 weight percent, based on the total weight of the composition. Typically, the total concentration is from 3 to 10 weight percent, such as from 5 to 8 weight percent, based on the total weight of the chiral liquid crystal precursor composition.

Additional information concerning substance I, II and the III second modifier may be found in U.S. patent application No.12/783,068 filed 5/19/2010; 12/783,078, respectively; 12/783,081 and 12/783,088, the entire disclosures of which are expressly incorporated herein by reference.

In particular, if the chiral dopant composition is applied by the above-described printing techniques, e.g. by inkjet printing, the composition typically comprises a solvent to adjust its viscosity to a value suitable for the application (printing) technique. Typical viscosity values for ink jet printing inks are from about 4 to about 30mpa.s at 25 ℃. Suitable solvents are known to those skilled in the art. Non-limiting examples thereof include low viscosity, slightly polar and aprotic organic solvents such as Methyl Ethyl Ketone (MEK), acetone, ethyl acetate, ethyl 3-ethoxypropionate, toluene and mixtures of two or more thereof. Other suitable components (resins, salts, etc.) required by the printing techniques used in the context of the present invention may also be present and are known to the person skilled in the art. For example, the chiral dopant composition may comprise one or more conductive agents, such as a salt that imparts sufficient conductivity to the chiral dopant composition to allow it to be used in combination with a printer, such as a continuous ink jet printer. Examples of suitable conductive agents include those described above as examples of conductive agents for use in the chiral liquid crystal precursor compositions of the present invention, such as tetrabutylammonium nitrate, tetrabutylammonium perchlorate, tetrabutylammonium hexafluorophosphate, potassium thiocyanate, lithium perchlorate, and other conductive agents known in the art.

After the chiral dopant composition is applied to one or more second areas (and optionally to one or more first areas or a portion thereof) of the initial chiral liquid crystal state chiral liquid crystal precursor composition having the initial set of optical properties, the one or more second areas produce a second modified chiral liquid crystal state having a second set of modified optical properties. To this end, at least the second area or areas to which the chiral dopant composition has been applied are heated, whereby the solvent contained in the composition, if present, is evaporated and promotion of the desired second modified chiral liquid crystal state takes place. The temperature used to evaporate the solvent and promote the formation of the second modified chiral liquid crystal state depends, for example, on the components of the chiral dopant composition, and in many cases is from about 55 ℃ to about 150 ℃, e.g., from about 55 ℃ to about 100 ℃, preferably from about 60 ℃ to about 100 ℃. Examples of suitable heating sources include conventional heating methods and in particular radiation sources such as IR lamps.

In the present identification, the deposition of the one or more second modifiers (substance I modifier and/or substance II modifier and/or substance III modifier) may be on one or more second areas of the chiral liquid crystal precursor composition in the initial chiral liquid crystal state (which may comprise or be only one or more first areas or portions thereof where the composition is in the first modified chiral liquid crystal state), preferably with a printing technique, in particular a technique selected from continuous ink jet printing, drop-on-demand ink jet printing, valve ink jet printing and spray coating. Advantages, particularly the speed and ease of formation of a marking that is generated in near real time, as compared to the prior art using lasers or extractants on polymerized or partially polymerized liquid crystals. Another advantage of using the above printing techniques is the accuracy and stability of the marking generated internally in the chiral liquid crystal state. Another advantage of using this printing technique is the almost limitless possibility of a marking that can be generated and changed in almost real time. In a preferred embodiment, inkjet technology is used to apply the modifying composition. Industrial inkjet printers, which are commonly used for regulating numbering and coding and marking applications on lines and printers, are particularly suitable. Preferred ink jet printers include single nozzle continuous ink jet printers (also known as raster or multi-level deflection printers) and drop on demand ink jet printers, particularly valve jet printers.

To enhance the resolution of the application indicia, it is generally advantageous to pass a stream of air over the surface of the applied chiral liquid crystal precursor composition, preferably (substantially) parallel thereto, immediately after applying the second modifier to one or more second areas of the applied chiral liquid crystal precursor composition. The air stream may be generated by any method, such as with an industrial air dryer. The air flow is preferably not intense and/or has a high velocity. The temperature of the air is typically ambient (e.g., about 20 ℃), but may be somewhat lower or higher, such as up to about 60 ℃, up to about 40 ℃, or up to about 30 ℃. The phrase "immediately after application of the second modifier" means without doubt, for example, a period of time within not greater than about 10 seconds, such as not greater than about 5 seconds, not greater than about 3 seconds, not greater than about 2 seconds, or not greater than about 1 second after application of the second modifier is complete.

The area of the applied chiral liquid crystal precursor composition to which each of the first and second (and any other) modifiers is applied is typically from about 0.1 to about 99.9% of the total area of the applied chiral liquid crystal precursor composition. The area is typically at least about 1%, such as at least about 5% or at least about 10% and not greater than about 99%, such as not greater than about 95% or not greater than about 90% of the total area of the applied chiral liquid crystal precursor composition.

As in the case of the first modifier, it is of course possible to use more than one second modifier (for example 2,3 or more different second modifiers) and apply them simultaneously and/or sequentially on the applied chiral liquid crystal precursor composition (for example in different areas of the applied chiral liquid crystal precursor composition). By way of example only, the different second modifiers may comprise two different species III modifiers, or they may comprise a species I modifier, a species II modifier, and a species III modifier, or they may comprise two different species II modifiers and a species I modifier, and the like. It is also possible, for example, to apply a first second modifier, followed by applying a different second modifier to at least a portion of the area in which the first second modifier has first been applied (and optionally also in one or more areas in which the first second modifier has not been applied). In this regard, it should be further understood that, particularly in the case of the use of a substance I modifier and a substance II modifier and/or a substance III modifier, it may be desirable, for convenience, to also perform the required heating of the substance II or substance III modifier in the case of the substance I modifier. In other words, although not necessarily, after application of the substance I modifier (and optionally air passing over the surface of the chiral liquid crystal precursor composition), the chiral liquid crystal precursor composition may be (re) heated to further modify the chiral liquid crystal state and/or to remove any residual solvent present in the substance I modifier. In most cases, however, no (additional) heating operation is required after application of the substance I modifier. If used, in many cases the temperature for this (optional) heating operation is from about 55 to about 150 ℃, e.g., from about 55 to about 100 ℃, or from about 60 to about 100 ℃. Examples of suitable heating sources include conventional heating methods and in particular radiation sources such as IR lamps.

Especially when two or more different second modifiers are used, the printing process can be carried out with a multi-head system (having, for example, 2,3, 4, 5 or more heads), wherein each head contains a different modifier. The advantage of this configuration is that during the printing process, a sequentially different modification of the initial chiral liquid crystal state and thus a large number of unique identifiers can be obtained. With a multi-head system, it is also possible to obtain different regions with different optical properties on the same mark, which itself constitutes a unique mark (especially when it is in the form of a data matrix). Examples of such data matrices with various multi-color data matrices are described, for example, in WO2008/127950 and WO01/24106, the entire disclosures of which are incorporated herein by reference.

To enhance the security of the markings of the present invention, the second modifier may further comprise one or more pigments and/or dyes that absorb in the visible or invisible region of the electromagnetic spectrum, and/or may further comprise one or more luminescent pigments and/or dyes. Non-limiting examples of suitable pigments and/or dyes that absorb in the visible or invisible region of the electromagnetic spectrum include phthalocyanine derivatives. Non-limiting examples of suitable luminescent pigments and/or dyes include lanthanide derivatives. The presence of pigments and/or dyes enhances and strengthens the security of the identification against counterfeiting. Of course, in addition to the components described above, the modifying composition used in the present invention may comprise any other components/materials that do not adversely affect the desired properties of the modifying composition to any significant extent.

The present invention identifies compositions that are ultimately obtained by curing and/or polymerizing compositions that are locally modified (in one or more areas) by the action of the first and second modifiers (and any other modifiers if desired). The immobilization (fixing) or hardening is preferably performed by irradiation with UV light which initiates the polymerization of the polymerizable groups present in the chiral liquid crystal precursor composition (and optionally in the modifier).

Thus, the overall process for preparing the inventive logo may comprise the following steps (using one first modifier and one second modifier):

-providing a functionalized substrate comprising a first modifier on the surface of the substrate or article;

-at least partially, e.g. fully curing and/or drying, the applied modifying resin;

-applying a (salt-containing) chiral liquid crystal precursor composition onto a portion of the substrate having the modified resin thereon such that the chiral liquid crystal precursor composition covers the modified resin in one or more first areas of the applied composition;

-heating the applied chiral liquid crystal precursor composition to bring it to a chiral liquid crystal state;

-applying a second modifier to one or more second areas of the chiral liquid crystal precursor composition in a chiral liquid crystal state;

-heating the chiral liquid crystal precursor composition to which the second modifier (for the substance II and the substance III modifiers) has been applied;

-curing/polymerizing (and optionally completing curing and/or drying of the modified resin) the liquid crystal precursor composition in the chiral liquid crystal polymer state to obtain the marking of the invention.

It is indicated here that sufficient curing/polymerization of the chiral liquid crystal precursor composition does not occur until the end of the production process.

By functionalized matrix is meant a matrix as described above (e.g. at least one cured and/or dried resin as described above, see fig. 1) comprising the first modifier of the invention.

The following examples are intended to illustrate the invention without limiting it.

Example 1

The PET substrate (thickness 50 μm) was functionalized with a UV-curable resin used as a first modifier. The first modifier is deposited on the substrate in one or more first areas using a flexographic printing process and cured with a UV dryer. The functionalized substrate was placed on a conveyor belt and passed through a first continuous inkjet nozzle (head 1; CLJ printer from Domino, uk; jet pressure 2500-. Head 1a layer of composition 1 (thickness 5 μm) was applied to the functionalized substrate. The thus coated substrate was thereafter heated with an IR lamp (Strip IR, PCS Inc. & Research Inc., usa; lamp intensity 15 cm; 500W max) for about 1 second, thereby promoting the chiral liquid crystal state of composition 1. At this stage, the chiral liquid crystal layer on the functionalized substrate comprises one or more first areas having a first modified set of optical properties (located in the area where the resin has been deposited) that is different from the initial set of optical properties resulting from the application of composition 1 directly to the substrate (i.e. in the absence of the first modifying agent). In a subsequent step, the substrate having the chiral liquid crystal layer thereon is passed through a second continuous inkjet nozzle (head 2) which applies a second modifier (see composition 2 below) to the substrate in one or more areas where the first modifier is not applied. The resulting product was subjected to a flow of ambient air. It was observed that in the areas where the second modifier had been deposited, a second modified set of optical properties appeared. The second set of properties is different from the initial set of optical properties and different from the first set of optical properties. The matrix with three different areas (initial, first and second areas) was then subjected to curing with a UV dryer (see above) to fix the liquid crystalline polymer state and to obtain the inventive marking with at least three sets of different optical properties.

Composition 1

Components	%
		Cholesteric Compound B	6.80
Nematic compounds A1	18.00
		Nematic compounds A2	18.00
TBAClO4	0.60
		LiClO4	0.40
Irgacure907	1.25
		DETX	0.70
Silane	1.00
		Acetone (II)	53.25

TBAClO₄= tert-butyl ammonium perchlorate

DETX =2, 4-diethylthioxanthone

Composition 2:

components	%
		Chlorinated polyolefins	5.00
Polyvinyl butyral	5.00
		KPF6	0.60
Fluorescent labeling agent	4.00
		MIBK	10.00
MEK	75.40

MIBK = methyl isobutyl ketone

MEK = methyl ethyl ketone

Example 2

Example 1 was repeated, but composition 2 was replaced with composition 3 described below. In contrast to example 1, after application of composition 3, the resulting product was not only subjected to a stream of ambient air, but also heated with an IR lamp for about 1 second to promote the chiral liquid crystal state of composition 3.

The procedures described in examples 1 and 2 are illustrated in figure 1.

Composition 3:

components	%
		Cholesteric Compound B	7.50
Nematic compounds A1	17.65
		Nematic compounds A2	17.65
TBAClO4	0.60
		LiClO4	0.40
Irgacure907	1.25
		DETX	0.70
Silane	1.00
		Acetone (II)	53.25

Examples 3 and 4

Examples 1 and 2 were repeated except that head 2 applied composition 2 (example 1) or composition 3 (example 2) to one or more second areas that either completely or partially overlapped or were within one or more first areas, thereby producing one or more areas having a (third) modified set of optical properties that was different from the initial, first and second modified sets of properties. Corresponding patterns, including those obtained according to examples 1 and 2, are illustrated in fig. 2. This allows, for example, to generate a data matrix that is a sum of points with different optical properties (e.g., different colors) within a limited area, thereby enhancing the security level (if, for example, the second modifier comprises a fluorescent dye). The identification of the data matrix code form as generated in the embodiment is shown in fig. 3 as follows: the first modifier is rectangular in shape, where it is superimposed in the form of a data matrix with a layer of liquid crystalline polymer that has been further modified by the second modifier.

It should be noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the invention has been described with reference to exemplary embodiments, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes in their aspects may be made within the purview of the appended claims as described and modified herein without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein; rather, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.

Claims (50)

1. A marking on an article or substrate, wherein the marking comprises a layer or pattern of a chiral liquid crystal polymer composition, said layer or pattern exhibiting an initial set of optical properties and being prepared by curing a chiral liquid crystal precursor composition in a chiral liquid crystal state, and wherein the layer or pattern comprises:

(1) one or more areas having a first modified set of optical properties, the first modified set of optical properties being different from the initial set of optical properties and being obtainable by contacting the chiral liquid crystal precursor composition in the one or more first areas with a first modifying agent;

(2) one or more second areas having a second modified set of optical properties, different from the initial set of optical properties and different from the first modified set of optical properties, and obtainable by contacting the chiral liquid crystal precursor composition in the one or more second areas with a second modifying agent, the second modifying agent being of a different type than the first modifying agent.

2. The marking of claim 1, wherein at least one first area partially or completely overlaps with a second area and/or at least one second area partially or completely overlaps with a first area.

3. The marking of any one of claims 1 and 2, wherein the at least one first area does not overlap any second area and/or the at least one second area does not overlap any first area.

4. The marking of any one of claims 1 to 3, wherein the initial, first and second sets of modified optical properties differ in at least one property of light reflected by the chiral liquid crystal polymer composition.

5. The marking of claim 4, wherein the at least one property is selected from the group consisting of spectrum, polarization, and λ of the reflected light_max。

6. The marking of any one of claims 1 to 5, wherein the initial, first and second set of optical properties comprises at least one property exhibiting an optically anisotropic state of the chiral liquid crystalline polymer composition and/or exhibiting a conversion of the optically anisotropic state into an optically isotropic state.

7. The marking of anyone of claims 1 to 6, wherein the chiral liquid crystal precursor groupThe compounds comprise (i) one or more nematic compounds A, (ii) one or more chiral dopant compounds B capable of giving rise to a cholesteric state of a chiral liquid crystal precursor composition, and (iii) at least one salt, the maximum wavelength (λ) of the selective reflection band exhibited by the polymer composition in the absence of the at least one salt_max) In contrast, it changes the maximum wavelength (λ) of the selective reflection band exhibited by the polymer composition_max)。

8. The marking of claim 7, wherein the one or more nematic compounds A and the one or more chiral dopant compounds B comprise at least one compound comprising at least one polymerizable group.

9. The marking of claim 8, wherein at least one of the polymerizable groups comprises an unsaturated carbon-carbon bond.

10. The marking of claim 8, wherein at least one polymerizable group comprises the formula H₂C = CH-C (O) -.

11. The marking of any one of claims 7 to 10, wherein all of the one or more nematic compounds a and all of the one or more chiral dopant compounds B comprise at least one polymerizable group.

12. The marking of anyone of claims 7 to 11, wherein the chiral liquid crystal precursor composition comprises at least one chiral dopant compound B of formula (I):

wherein:

R₁、R₂、R₃、R₄、R₅、R₆、R₇and R₈Each independently represents C₁-C₆Alkyl and C₁-C₆An alkoxy group;

A₁and A₂Each independently represents a group of formulae (i) - (iii):

(i)-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(ii)-C(O)-D₁-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

(iii)-C(O)-D₂-O-[(CH₂)_y-O]_z-C(O)-CH=CH₂；

D₁a group represented by the formula:

D₂a group represented by the formula:

m, n, o, p, q, r, s and t each independently represent 0, 1 or 2;

y represents 0, 1, 2,3, 4, 5 or 6;

if y is equal to 0, then z is equal to 0, and if y is equal to 1-6, then z is equal to 1.

13. The marking of any one of claims 7 to 12, wherein the at least one salt is selected from the group consisting of metal salts and ammonium salts.

14. The marking of claim 13, wherein the at least one salt comprises at least one of: lithium perchlorate, lithium nitrate, lithium tetrafluoroborate, lithium bromide, lithium chloride, tetrabutylammonium perchlorate, tetrabutylammonium chloride, tetrabutylammonium tetrafluoroborate, tetrabutylammonium bromide, sodium carbonate, sodium chloride and sodium nitrate.

15. The marking of anyone of claims 1 to 14, wherein the chiral liquid crystal precursor composition is in an optically anisotropic state, and wherein in one or more first areas the optically anisotropic state changes to a first modified optically anisotropic state and/or in one or more second areas the optically anisotropic state changes to a second modified optically anisotropic state or converts to an optically isotropic state.

16. The marking of any one of claims 1 to 15, wherein the chiral liquid crystal precursor composition is in an initial chiral liquid crystal state, and wherein in one or more first areas the initial chiral liquid crystal state is changed to a first modified chiral liquid crystal state by a first modifier, and in one or more second areas the initial chiral liquid crystal state is changed to a second modified chiral liquid crystal state or converted to an achiral liquid crystal state by a second modifier.

17. The marking of any one of claims 1 to 16, wherein the first modifying agent is a solid and/or semi-solid and the second modifying agent is a fluid.

18. The marking of any one of claims 1 to 17, wherein the first modifying agent is substantially impermeable to the composition in the uncured state and the second modifying agent at least partially penetrates the composition in the uncured state.

19. The marking of any one of claims 1 to 18, wherein the first modifying agent is or comprises a resin composed of one or more polymerizable monomers.

20. The marking of claim 19, wherein at least one of the one or more polymerizable monomers comprises at least two unsaturated carbon-carbon bonds.

21. The marking of any one of claims 19 and 20, wherein at least one of the one or more polymerizable monomers comprises at least one heteroatom selected from the group consisting of O, N and S.

22. The marking of any one of claims 19 to 21, wherein at least one of the one or more polymerizable monomers comprises at least one of the formula H₂C = CH-C (O) -or H₂C=C(CH₃) The group of-C (O) -.

23. The marking of any one of claims 19 to 22, wherein the resin comprises a radiation curable resin.

24. The marking of claim 23, wherein the radiation curable resin comprises a UV curable resin.

25. The marking of any one of claims 19 to 24, wherein the resin comprises a dried aqueous resin.

26. The marking of any one of claims 1 to 25, wherein the second modifying agent is a fluid and is selected from one or more of the group consisting of: (a) a modified composition comprising at least one compound selected from the group consisting of ketones having 3 to about 6 carbon atoms, alkyl esters and dialkylamides of carboxylic acids containing a total of 2 to about 6 carbon atoms, dihydrocarbyl sulfoxides containing a total of 2 to about 4 carbon atoms, and optionally substituted nitrobenzene, (b) a modified composition comprising at least one chiral liquid crystal precursor composition, and (c) a modified composition comprising at least one chiral dopant composition.

27. The marking of claim 26, wherein the first modifying agent is selected from the group consisting of solid or semi-solid cured and/or dried resins prepared from one or more polymerizable monomers, and both the first modifying agent and the second modifying agent modify the initial maximum wavelength (λ) of the selective reflection band exhibited by the chiral liquid crystal precursor composition in the chiral liquid crystal state_max)。

28. The marking of any one of claims 1 to 27, wherein the first modifying agent and the second modifying agent act from opposite sides of a layer or pattern of the chiral liquid crystal precursor composition.

29. The marking of any one of claims 1 to 28, wherein the one or more first areas and/or the one or more second areas are in the form of at least one of: images, pictures, logos, indicia, and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

30. The marking of any one of claims 1 to 29, wherein at least a portion of the composition is in the form of at least one of: images, pictures, logos, indicia, and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

31. The marking of any one of claims 1 to 30, wherein the article or substrate is or comprises at least one of: a label, package, cassette, container or capsule comprising a food product, nutraceutical product, pharmaceutical product or beverage, a banknote, a credit card, a stamp, a tax label, a security seal, a security document, a passport, an identification card, a driver's license, an access card, a transportation ticket, an admission ticket, a voucher, an ink transfer film, a reflective film, an aluminium foil and a commercial product.

32. A method of providing a marking on an article or substrate, wherein the method comprises:

a) applying to the surface of the article or substrate bearing the first modifying agent in one or more first areas a curable chiral liquid crystal precursor composition which assumes an initial chiral liquid crystal state upon heating it in such a way that the composition covers at least a portion of the one or more first areas, wherein the first modifying agent is capable of modifying the initial chiral liquid crystal state of the composition;

b) heating the applied composition to produce a first modified chiral liquid crystal state in one or more first areas and an initial chiral liquid crystal state, if any, in all other areas of the applied composition;

c) applying to one or more second areas of the applied composition at least one second modifying agent, which is of a different type than the first modifying agent and which (1) is capable of locally modifying the initial and/or first modified chiral liquid crystal state provided by b), or (2) is capable of locally modifying the initial and/or first modified chiral liquid crystal state provided by b) upon heating of the composition;

d) in the case of (2), heating the composition in at least the one or more second areas; and

e) curing the thus modified chiral liquid crystal precursor composition to produce a chiral liquid crystal polymer marking on the article or substrate.

33. The method according to claim 32, wherein at least one of the one or more first areas partially or completely overlaps at least one of the one or more second areas, or vice versa.

34. The method according to any one of claims 32 and 33, wherein the chiral liquid crystal precursor composition comprises: (i) one or more nematic compounds a, (ii) one or more chiral dopant compounds B in a cholesteric state capable of giving rise to a chiral liquid crystal precursor composition, and (iii) at least one salt which exhibits, with a polymer composition which does not contain at least one salt, a maximum wavelength (λ) of the selective reflection band_max) In contrast, compositions that change the state of a chiral liquid crystal exhibit a maximum wavelength (λ) of the selective reflection band_max)。

35. The method according to claim 34, wherein the composition in which the first modifying agent is capable of modifying the chiral liquid crystal state exhibits a maximum wavelength (λ) of the selective reflection band_max)。

36. The method according to any one of claims 34 and 35, wherein the composition in which the second modifier is capable of altering the chiral liquid crystal state exhibits a maximum wavelength (λ) of the selective reflection band_max)。

37. The method of any one of claims 32-36, wherein the first modifying agent is a solid or semi-solid and the second modifying agent is a fluid.

38. The method of any of claims 32-37, wherein the first modifier is a resin comprised of one or more polymerizable monomers.

39. The method of claim 38, wherein the resin comprises a radiation curable resin.

40. The method of claim 38, wherein the resin comprises a dried aqueous resin.

41. The method of any of claims 32-40, wherein the second modifier is a fluid and is selected from one or more of the following: (a) a modified composition comprising at least one compound selected from the group consisting of ketones having 3 to about 6 carbon atoms, alkyl esters and dialkylamides of carboxylic acids containing a total of 2 to about 6 carbon atoms, dihydrocarbyl sulfoxides containing a total of 2 to about 4 carbon atoms, and optionally substituted nitrobenzene, (b) a modified composition comprising at least one chiral liquid crystal precursor composition, and (c) a modified composition comprising at least one chiral dopant composition.

42. The method of any one of claims 32-41, wherein b) and/or d) comprises heating the composition to a temperature of from about 55 to about 150 ℃.

43. The method of any of claims 32-42, wherein the composition is applied by at least one of: spray coating, knife coating, roll coating, screen coating, curtain coating, gravure printing, flexographic printing, screen printing, pad printing, continuous ink jet printing, drop-on-demand ink jet printing, and valve jet printing.

44. The method of any of claims 32-43, wherein the composition is applied in at least one of the following forms: images, pictures, logos, indicia and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

45. A method according to any one of claims 32 to 44, wherein the first modifier is provided on the article or substrate by at least one of: spray coating, knife coating, roll coating, screen coating, curtain coating, gravure printing, flexographic printing, offset printing, dry offset printing, letterpress printing, screen printing, pad printing, continuous ink jet printing, drop-on-demand ink jet printing, and valve jet printing.

46. The method according to any one of claims 32 to 45, wherein the first modification agent is provided on the article or substrate in one or more first areas in the form of at least one of: images, pictures, logos, indicia and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

47. The method of any of claims 32 and 46, wherein the second modifier is applied by at least one of: continuous ink jet printing, drop on demand ink jet printing, spray coating, and valve jet printing.

48. The method of any of claims 32-48 wherein the second modifier is applied to the one or more second areas in the form of at least one of: images, pictures, logos, indicia and patterns representing a code selected from one or more of: 1-dimensional bar code, stacked 1-dimensional bar code, 2-dimensional bar code, 3-dimensional bar code, cloud of dots, network of lines, and data matrix.

49. A method according to any one of claims 32 to 48, wherein the article or substrate is or comprises at least one of: a label, package, cassette, container or capsule comprising a food, beverage, nutraceutical or pharmaceutical product, a banknote, a credit card, a stamp, a tax label, a security seal, a security document, a passport, an identification card, a driver's license, an access card, a transportation ticket, an admission ticket, a voucher, an ink transfer film, a reflective film, an aluminium foil and a commercial good.

50. An article or substrate obtainable by the method of any one of claims 32 to 49.