WO2004032099A1

WO2004032099A1 - Liquid crystal label, liquid crystal continuous body, and method of producing the liquid crystal label

Info

Publication number: WO2004032099A1
Application number: PCT/JP2003/012384
Authority: WO
Inventors: Misao Nakamura; Shin'ichi Ono
Original assignee: Osaka Sealing Printing Co., Ltd.
Priority date: 2002-09-30
Filing date: 2003-09-29
Publication date: 2004-04-15
Also published as: JP4593602B2; JPWO2004032099A1; JP4033864B2; JP2007334363A; AU2003266665A1

Abstract

A liquid crystal label, a liquid crystal label continuous body, and a method of producing the liquid crystal label. The liquid crystal label is pliable, easily adhered to a surface where the label is to be adhered, can be produced at relatively low cost, and can be used as an anti-counterfeit label. A liquid crystal label (10) comprises a base material (12) with transparency or semi-transparency, a liquid crystal layer (14) formed on the rear face side of the base material (12), a background layer (16) formed on a face of the liquid crystal layer (14) with the face being on the opposite side of the base material (12), and an adhesive agent layer (18) formed on a face of the background layer (16) with the face being on the opposite side of the liquid crystal layer (14). A method of producing the liquid crystal label comprises a step of forming a liquid crystal layer on the rear face side of a base material with transparency or semi-transparency, a step of forming a background layer on a face of the liquid crystal layer with the face being on the opposite side of the base material, and a step of forming an adhesive agent layer on a face of the background layer with the face being on the opposite side of the liquid crystal layer.

Description

Description Liquid crystal label, liquid crystal label continuum and liquid crystal label manufacturing method

The present invention relates to a liquid crystal label, a liquid crystal label continuum, and a method for producing a liquid crystal label, and more particularly to, for example, a liquid crystal label, a liquid crystal label continuum suitable for use as a label capable of preventing forgery, and a method for producing the same. Background art

Conventionally, the label recording layer is formed by thermal recording, thermal coloring, printing, etc., so it is relatively easy to create a fake label, and the difference between the fake and the real one is difficult to see. Have. In addition, a label using a material that emits light when irradiated with ultraviolet light or infrared light can be identified as a fake only by irradiating ultraviolet light or infrared light, and it is difficult to determine the authenticity only by visual inspection. .

Therefore, a label that can identify authenticity has been proposed, such as an authenticity identification label disclosed in Japanese Patent Application Laid-Open No. 2002-205471.

This conventional authenticity identification label uses a display material containing a cholesteric liquid crystal pigment, which is rarely used as a display material for a conventional label. Since it cannot be demonstrated, it is suitable as a forgery prevention label because its forgery is difficult.

However, because the configuration is difficult to achieve the object of the invention, the cost of the label also increases, for example, to prevent forgery of low unit price parts. Not suitable for use as a label and poor in flexibility. That is, a microsphere transparent bead having a diameter of 10 to 100 ^ m, preferably 50 m or less, is preferably formed on a layer such as a liquid crystal layer while the layer still does not lose its tackiness. Involves a difficult-to-control operation in which glass (hard) beads must be formed in a single layer, preferably with no more than two layers, so there is a problem with the reproducibility of production. However, the yield must be reduced, manufacturing costs rise, and the flexibility is insufficient.

Therefore, those who do not use the operation of aligning the microbeads or the operation of laminating other layers with the liquid crystal layer having adhesiveness are more reproducible for labels with the same performance, It is easy to manufacture counterfeit prevention labels that can be manufactured at a high yield and at a relatively low cost, and that can be distinguished from general-purpose labels immediately by simply observing the label while changing the viewing direction. Therefore, a main object of the present invention is to provide a liquid crystal which is flexible, can be easily attached along the surface of an adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. An object of the present invention is to provide a label, a liquid crystal label continuum, and a method for producing the same. Disclosure of the invention

The liquid crystal label according to claim 1 of the present invention includes a transparent or translucent base material, a liquid crystal layer formed on the back surface side of the base material, and a liquid crystal layer on a surface opposite to the base material. A liquid crystal label including a background layer formed and an adhesive layer formed on a surface of the background layer opposite to the liquid crystal layer.

The liquid crystal label according to claim 2 of the present invention is the liquid crystal label according to claim 1, wherein the liquid crystal layer contains a liquid crystal composition comprising a cholesteric phase.

In the liquid crystal label according to claim 3 of the present invention, the liquid crystal layer is 3. The liquid crystal label according to claim 1, which is partially formed on a back surface.

The liquid crystal label according to claim 4 of the present invention, wherein the concealing layer is formed partially on the back surface of the base material, and the liquid crystal layer is formed on the back surface of the base material so as to cover the concealing layer. A liquid crystal label according to claim 1 or claim 2.

The liquid crystal label according to claim 5 according to the present invention is the liquid crystal label according to any one of claims 1 to 4, wherein the background layer has a portion having a difference in the absorptivity of infrared rays.

The liquid crystal label according to claim 6 according to the present invention, wherein a portion provided with a difference in absorptivity of infrared rays in the background layer is configured not to be identified under visible light. It is.

The liquid crystal label according to claim 7 of the present invention is configured such that at least one of the adhesive strength between the layers and the cohesive failure strength of each layer excluding the adhesive layer is weaker than the cohesive failure strength of the adhesive layer. A liquid crystal label according to any one of claims 1 to 6, wherein

In the liquid crystal label according to claim 8 of the present invention, the adhesive strength between the substrate and the liquid crystal layer is lower than the adhesive strength between the liquid crystal layer and the background eyebrows, lower than the adhesive strength between the background layer and the adhesive layer, and The liquid crystal label according to claim 7, wherein the liquid crystal label is configured to be weaker than the cohesive failure strength of each of the liquid crystal layer, the background layer, and the adhesive layer.

In the liquid crystal label according to claim 9 of the present invention, the cohesive failure strength of the liquid crystal layer, the background layer, and the adhesive layer among the liquid crystal layer, the background layer, and the adhesive layer is such that: Weaker than the cohesive failure strength of the other layers, weaker than the adhesive strength between the substrate and the liquid crystal layer, weaker than the adhesive strength between the liquid crystal layer and the background layer, and weaker than the adhesive strength between the background layer and the adhesive layer A liquid crystal label according to claim 7, wherein The liquid crystal label according to claim 10 of the present invention has an adhesive strength between the substrate and the liquid crystal layer, an adhesive strength between the liquid crystal layer and the background layer, an adhesive strength between the background layer and the adhesive layer, and cohesive failure of the liquid crystal layer. 8. The liquid crystal label according to claim 7, wherein at least one of the cohesive failure strength of the adhesive layer and the background layer is weaker than the cohesive fracture strength of the adhesive layer.

The liquid crystal label continuum according to claim 11 of the present invention has a transparent or translucent substrate, the surface of which has a peeling property, and a liquid crystal layer formed on the back side of the substrate. And a background layer formed on the surface of the liquid crystal layer opposite to the base material, and an adhesive layer formed on the surface of the background layer opposite to the liquid crystal layer, with the surface of the base material facing outward. The liquid crystal label string is wound with the adhesive layer inside. .

In the liquid crystal label continuum according to claim 12 of the present invention, the label is

A transparent or translucent substrate, a liquid crystal layer formed on the back side of the substrate, a background layer formed on the surface of the liquid crystal layer opposite to the substrate, and a liquid crystal layer of the background layer The label is a liquid crystal label continuum temporarily attached to the separator on the side opposite to the background layer of the adhesive layer.

A method for producing a liquid crystal label according to claim 13 according to the present invention, comprising: a step of forming a liquid crystal layer on the back surface side of a transparent or translucent substrate; and a surface of the liquid crystal layer opposite to the substrate. Forming a background layer, and forming an adhesive layer on the surface of the background layer opposite to the liquid crystal layer.

The method for producing a liquid crystal label according to claim 14 of the present invention is characterized in that the step of forming the liquid crystal layer comprises applying a coating liquid for forming a liquid crystal layer and heating to a temperature at which a cholesteric phase can be formed. Forming a cholesteric phase by UV irradiation and UV crosslinking to fix the cholesteric phase. Item 14. A method for producing a liquid crystal label according to Item 13.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an illustrative sectional view of a liquid crystal label according to an embodiment of the present invention.

FIG. 2 is an illustrative view showing a molecular arrangement of a cholesteric phase.

FIG. 3 is an illustrative plan view showing a method for manufacturing a label continuous body.

FIG. 4 is an illustrative sectional view of a liquid crystal label according to another embodiment of the present invention.

FIG. 5 is an illustrative sectional view of a liquid crystal label according to still another embodiment of the present invention.

FIG. 6 is a schematic plan view of the liquid crystal label shown in FIG. 5 when viewed under visible light.

FIG. 7 is an illustrative view showing an image in which the surface of the liquid crystal label shown in FIG. 5 is irradiated with infrared rays in the dark and reflected light from the surface side of the liquid crystal label is captured by a CCD camera. BEST MODE FOR CARRYING OUT THE INVENTION ''

The liquid crystal label 10 includes a substrate 12 made of a synthetic resin sheet or film such as a transparent or translucent polyester film, and a cholesteric liquid crystal formed on the back surface of the substrate 12. Will be fixed A liquid crystal layer 14; a background layer 16 formed on the surface of the liquid crystal layer 14 opposite to the base material 12 to enhance the glitter of the liquid crystal layer 14; An adhesive layer 18 formed by applying an adhesive or the like formed on the surface of the background layer 16 opposite to the liquid crystal layer 14 side.

The substrate 12 is preferably made of a plastic film such as PET or a sheet made of transparent PET or the like. In particular, the surface of the substrate 12 on which the liquid crystal layer 14 is formed (ie, the surface of the substrate 12) ) Increases the transparency, and when the liquid crystal label 10 is to be peeled off from the adherend, the liquid crystal layer 14 has a smoothness to facilitate delamination between the liquid crystal layer 14 and the liquid crystal layer 14. It is desirable that the surface side on which the liquid crystal layer is formed is not surface-treated in order to facilitate delamination between the base material 12 and the liquid crystal layer 14. . Occasionally, fine linear traces are formed in the longitudinal direction of the base material 12 on the surface of the base material 12 on which the liquid crystal layer 14 is formed in order to promote the orientation of the liquid crystal molecules constituting the liquid crystal layer 14. Is also good.

A cholesteric liquid crystal is selected as a liquid crystal composition constituting the liquid crystal layer 14. The cholesteric liquid crystal is formed by applying a compound having a cholesteric phase having a helical structure or a chiral nematic phase (see FIG. 2).

Examples of the compound having a cholesteric phase or a chiral nematic phase include cholesteryl nonanoate, cholesteryl myristate, and the like, as shown in Table 1.

(Hereinafter the margin) I A.

. ◦ P Π

OO P

o

o ί

CO

oO. Re

▼

¾. . . 09

〇

(Note in Table 1) In the column of phase transition temperature in Table 1, C is a crystalline solid, S is a smectic phase, S c * is a chiral smectic C phase, Ch is a cholesteric phase, and N * is a chiral nematic phase. , I represent an isotropic liquid. In addition, a chiral nematic phase can be formed by adding the chiral compound shown in Table 3 to the compound having a nematic phase alone shown in Table 2 (hereinafter, cholesteric phase and chiral nematic phase are not distinguished from each other. Phase).

(Hereinafter the margin)

Table 2

υ

(Note of Table 2) In Table 2, 檷 in the phase transition temperature, C indicates a crystalline solid, N indicates a nematic phase, and I indicates an isotropic liquid. Table 3

(Note in Table 3) When a chiral molecule is added to a liquid crystal that exhibits a nematic phase, a chiral nematic phase (Ν *) is obtained. In this case, the pitch of the mixed liquid crystal Reciprocal l / p of the molar concentration chi _beta chiral molecules in a small area, is proportional to the chi _beta. Therefore, l Zp x _B is called chiral torsional force.

The liquid crystal layer 14 according to the present invention has a fixed cholesteric phase. For example, a method for fixing the liquid crystal layer is to have an acryl group at both ends of the liquid crystal molecule, and use this as a base material 12. The cholesteric phase is heated to a temperature at which a cholesteric phase can be formed, a cholesteric phase is formed, and UV irradiation is performed to fix the cholesteric phase by UV crosslinking. Therefore, the cholesteric phase exists stably even when the environment such as temperature changes.

Alternatively, a mixture of liquid crystal molecules and a commonly used binder may be applied, heated to a temperature at which a cholesteric phase can be formed, a cholesteric phase is formed, dried, and the cholesteric phase is fixed with the binder. The coating liquid for forming a liquid crystal layer may be solvent-based or non-solvent-based.

In the solvent system, ketones such as ΜΕΚ and 、, toluene, and ethyl acetate are preferred as the solvent. The solid content is not particularly limited, but is preferably 25 to 67%. If the amount is less than 25%, the image may not be clearly formed, and the time required for drying becomes longer. If it exceeds 67%, solids may precipitate unless the coating liquid is heated. A particularly preferred concentration range is 50-65%. In order to eliminate the risk of solid deposition due to evaporation of the solvent from the coating liquid, coating is performed while heating the coating liquid. In the case of a non-solvent system, coating is performed while heating the coating composition to a temperature equal to or higher than the lowest temperature at which a cholesteric phase is formed, and preferably to a temperature in a temperature range where a cholesteric phase is formed.

In order to fix the cholesteric phase formed in the coating material, whether solvent-based or non-solvent-based, crosslink, etc., while maintaining the liquid crystal layer forming coating material within the temperature range where the cholesteric phase is formed . As a result, cholesteric The phase is maintained stably even when the temperature environment changes, for example, at room temperature.

The liquid crystal layer 14 composed of a cholesteric phase exhibits brilliancy, and the color tone changes continuously depending on the viewing direction. For example, when viewed vertically from above, it looks green, and when viewed near horizontal, it looks blue.

The liquid crystal layer 14 exhibiting the cholesteric phase is characterized in that only a part of the wavelength region of light incident in a wide spectral region is reflected, and all wavelengths in other regions are transmitted.

The liquid crystal layer 14 is not formed on the entire back surface of the base material 12, but is formed by applying an image composed of characters, pictures, and the like to a liquid crystal layer forming coating liquid for forming the liquid crystal layer 14. It is formed so as to compose an object by forming convex characters and blank characters.

When the spiral pitch P (shown in Fig. 2) increases, colors on the long wavelength side appear, and when the spiral pitch P decreases, colors on the short wavelength side appear. To change the pitch, in a system to which a chiral compound has been added, the amount of the chiral compound added may be changed.

The background layer 16 is formed by printing and applying black ink or coloring ink such as red or blue. The background layer 16 is formed to enhance the glitter of the liquid crystal layer 14, and is formed over the entire back surface of the substrate 12 so as to cover the liquid crystal layer 14. In particular, as the background layer 16, the black color formed with black ink or the like is excellent for enhancing the glitter of the liquid crystal layer 14.

The color tone of the background layer 16 changes the visual color tone of the liquid crystal layer 14, so the composition and color of the ink forming the background layer 16 is important. For example, when the color of the background layer 16 is black, when the liquid crystal layer 14 is visually inspected, When the background layer 16 is red, the liquid crystal layer 14 shows orange to purple glitter when the background layer 16 is red, and the background layer 16 is colored near white. In this case, the liquid crystal layer 14 has a milky white or pearly tone.

Therefore, if the color forming the background layer 16 is divided into two or more colors, when the liquid crystal layer 14 is visually observed, a colorful liquid crystal label corresponding to the change in the color of the background layer 16 is obtained.

The adhesive layer 18 is formed by applying a general acrylic or rubber-based adhesive.

On the surface of the adhesive layer 18, a separator 20 made of a paper or the like coated with a release agent such as silicone is temporarily attached.

To prevent the liquid crystal label 10 from being broken and replaced with a fake label when the LCD label 10 attached to the adherend is to be peeled off from the adherend, for example, It is good also as a structure.

The adhesive strength between the substrate 12 and the liquid crystal layer 14 is the adhesive strength between the other layers, that is, in the case of FIG. 1, between the liquid crystal layer 14 and the background layer 16 and between the background layer 16 and the adhesive layer 18. The adhesive strength of each layer and the cohesive failure strength of each layer are configured to be weaker. As a method therefor, for example, there is a method of adjusting the adhesive strength between the base material 12 and the liquid crystal layer 14 without using any binder in the coating liquid for forming the liquid crystal layer or suppressing the amount of the binder.

Further, the cohesive fracture strength of the background layer 16 and / or the liquid crystal layer 14 may be configured to be weaker than the cohesive fracture strength of the other layers and the adhesive strength between the layers.

In this way, delamination is caused between the base material 12 and the liquid crystal layer 14, or cohesive failure occurs in the background layer 16 and the liquid crystal layer 14 and the liquid crystal label 10 is applied. If you try to remove it from your body, the LCD label 10 will be broken and you will be able to replace the label with another fake product and make the fake look genuine. And can not do.

(Example 1)

As a base material, a PET film (E_500, manufactured by Toyobo Co., Ltd.) with a width of 160 mm and a thickness of 50 m, which has not been subjected to any special surface treatment, is prepared. A coating liquid that is applied and forms a liquid crystal layer is prepared.

The following mixed coating liquid is used as the liquid crystal layer forming coating liquid.

Nematic liquid crystal having acrylyl groups at both ends (Paliocolor LC242 of BASF) · · · 55.3% by weight

Chiral compound (Paliocolor LC756 of BASF) 2.9% by weight UV polymerization initiator (Irgacure 369 of Ciba Specialty Chemicals) 1.8% by weight

Methyl ethyl ketone (MEK) as a solvent---40.0% by weight With this liquid crystal forming coating liquid, using a gravure plate, the thickness after drying including the pattern is adjusted so that the thickness after drying becomes 3 m. Coating is applied to form characters and blank characters, and pass through a drying zone (110 to 120 ° C) for 15 seconds to dry, forming a cholesteric phase. Immediately thereafter, UV irradiation is performed, UV curing is performed, and the cholesteric phase is fixed. The temperature at which a nematic liquid crystal is formed is not less than 59 ° C. and not more than 120 to 124. Thus, a liquid crystal layer composed of a stable cholesteric phase is formed on the base material (step of forming a liquid crystal layer).

Next, a black ink coating solution (PANN ECO, manufactured by Toyo Ink Manufacturing Co., Ltd.) for forming the background layer was prepared, and the black ink coating solution was gravure coated on the back surface of the base material so as to cover the liquid crystal layer. Apply with a stencil so that the average thickness after drying is 3 m. After that, the ink passes through the drying zone (70 to 80 ° C) for 3 seconds to dry the black ink coating liquid.

Thus, a background layer covering the liquid crystal layer is formed on the back surface of the base material. Steps to perform).

Next, separately prepare an adhesive coated on the surface of Separete, which is a paper on which the release agent such as silicone is coated on the surface of the paper, and a background layer formed on the back of the base material. The back surface of the side and the surface of the adhesive layer formed on the surface of the separator are opposed to each other, and both are laminated by passing between the laminating rollers (step of forming an adhesive layer).

Further, a laminate obtained by laminating the laminate comprising the base material, the liquid crystal layer and the background layer, the adhesive layer, and the laminate of the separator is formed into a label (20 × 70 mm) of an appropriate size. For this purpose, die-cutting is performed from the surface side of the base material to the surface of the adhesive layer side of the separator. In this way, after forming a predetermined label shape, unnecessary scraps other than the label are removed from the separation surface.

As shown in Fig. 3, these labels are formed in six rows at regular intervals (6 mm intervals) in the width direction of the separator, and the labels in each row are the length of the separator. They are arranged at regular intervals (3 mm intervals) in the direction. Therefore, the separators are slit at equal intervals between the labels arranged in six rows in the width direction, the separators are divided into six, and the labels are arranged on the surface of each separator at predetermined intervals. And created a label continuum that was continuously arranged.

The shapes of the labels and the intervals between the labels may be changed as appropriate. When viewed from the substrate side, the liquid crystal label of this example exhibited a vivid brilliancy that changed from green to blue-violet depending on the viewing direction.

Further, in this embodiment, since the liquid crystal layer is formed without using any binder in the liquid crystal layer forming coating liquid constituting the liquid crystal layer, the adhesive strength at the interface between the base material and the liquid crystal layer is reduced. Affixed to adherend (made of polypropylene) because it is weaker than adhesive strength between layers and cohesive failure strength of each layer An attempt was made to peel off the liquid crystal label attached to the adherend without destroying it.However, the label was peeled off between the base material and the liquid crystal layer, and the label was peeled off from the adherend without being destroyed. Could not.

In this example, the binder was not used in the liquid crystal layer forming coating liquid. However, even if a small amount of the binder was added, the amount of the binder was suppressed, as described above. Can be designed to be weaker than the adhesive strength of the interface between the other layers and the cohesive failure strength of each layer.

In this embodiment, a liquid crystal layer may be formed on the entire back surface of the base material. When the liquid crystal layer is formed on the entire back surface of the base material in this manner, an image-free liquid crystal label having almost the same brightness on the entire surface can be obtained.

FIG. 4 is an illustrative sectional view showing another embodiment of the liquid crystal label of the present invention.

The liquid crystal label 110 includes a transparent or translucent base material 112, a liquid crystal layer 114 formed on the back side of the base material 112, and a base material of the liquid crystal layer 114. A background layer 1 16 formed on the surface opposite to the material 1 12, and an adhesive layer 1 1 formed on the back surface of the background layer 1 16 opposite to the liquid crystal layer 114 side. 8 and a concealing layer 122 partially formed on the back surface of the substrate 112.

On the surface of the adhesive layer 118, a separator 120 formed by applying a release agent such as silicone to the surface of paper or the like is temporarily attached.

The liquid crystal label 110 of this embodiment has substantially the same configuration as the liquid crystal label 10 of the above embodiment, but has a concealing layer 122, and the concealing layer 122 is It is formed by the same ink as the ink forming the background layer 116. The concealing layer 122 may be translucent as long as it has a concealing property and does not allow the liquid crystal layer 114 to be seen through from the substrate 112. In order to form the liquid crystal layer 114 composed of the cholesteric phase, it is necessary to heat to a temperature range in which the cholesteric phase is formed. However, it does not form a cholesteric phase. When the temperature of the liquid crystal layer forming coating film after coating is once heated to a temperature higher than the temperature range where the cholesteric phase is formed, that is, the temperature at which the cholesteric phase is formed after being heated to the liquefaction temperature, the brilliancy is reduced. It is preferable that the drying after coating is not heated to the liquefaction temperature, since there is a possibility of lowering the sharpness of the image as well as the sharpness of the image. In addition, in the temperature range where a cholesteric phase is formed, setting the temperature as high as possible is advantageous in glitter and the like. This is the orientation of the cholesteric phase

It is supposed that (formation) is performed promptly and reliably.

After the cholesteric phase has been formed, it is necessary to fix the cholesteric phase by performing crosslinking at a temperature in the cholesteric phase formation temperature range in order to maintain the cholesteric phase stably.

Therefore, a concealing layer 122 that forms an object with black ink that does not have such a restriction or a concealable ink such as red and blue is formed, and the concealing layer 122 and the background layer 166 are formed. The configuration in which the liquid crystal layer 114 is formed on the entire surface in between increases the number of steps by one, but makes it easier to form a clearer image than the liquid crystal label 10 of the above embodiment.

Further, in this embodiment in which the liquid crystal layer is formed on the entire surface, the surface of the liquid crystal layer forming coating material applied on the base material 112 with, for example, a smoothing bar is used. Also, by applying a shear to the coating, it is possible to perform a cholesteric phase formation acceleration treatment for promoting the formation of a more reliably oriented cholesteric phase.

The thickness and material of the base material 112 are not particularly limited. However, when the base material 112 is too thin, it is difficult to apply a liquid crystal layer forming coating liquid or a background layer forming coating liquid. The thickness of the base material is more preferably about 25 or more, and conversely, if it is too thick, it will be stiff and small. When sticking to a surface having a curved surface or the like as described above, sticking becomes difficult, and therefore it is more preferably about ΙδΟ ^ πι or less. The background layer 116 and the concealing layer 122 need only have a thickness not less than the thickness at which the concealing effect is obtained. For example, the thickness is preferably 1 m or more, and more preferably about 2 to 5 m.

The liquid crystal layer 114 may be any thickness as long as the brightness is more than a visible thickness, and is preferably about 2 to 5 m, and if it is less than lzm, its concentration may be reduced. .

Desirably, when the liquid crystal label 110 is to be peeled off from the adherend, the base material 112 is peeled off from the liquid crystal layer 114, etc., or the liquid crystal layer 114, etc. is cohesively broken. For example, the liquid crystal label 110 may be configured to be broken. That is, if the user tries to remove the liquid crystal label 110 so as to prevent the label attached to the adherend from being peeled off and adhered to another fake adherend, the liquid crystal label 1 1 1 The structure is such that 0 is destroyed. For example, the following configuration may be used.

The adhesive strength between the base material 112 and the liquid crystal layer 114 is weaker than the adhesive strength between other layers and the cohesive failure strength of each layer. For example, there is a method of adjusting the adhesive strength between the base material 112 and the liquid crystal layer 114 without using a binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder. Also, the cohesive failure strength of the background layers 1 16 and Z or the liquid crystal layer 1 14 may be configured to be weaker than the cohesive failure strength of the other layers and the adhesive strength between the respective layers. Delamination between 1 1 2 and liquid crystal layer 1 1 4 In the background layer 1 16 and / or the liquid crystal layer 1 14, cohesive failure occurs, and when the liquid crystal label 110 is to be peeled off from the adherend, the liquid crystal label 110 is broken and You will not be able to relabel fake goods.

As described above, the liquid crystal label 110 is formed with the background layer 116 on the back surface of the liquid crystal layer 114, so that it is impossible to produce a label that is close to genuine by ordinary printing and copying techniques. Also, even if they have advanced printing technology, if they do not have knowledge of liquid crystals, especially liquid crystals composed of cholesteric phases, a stable liquid crystal layer in which the cholesteric phases are highly oriented cannot be obtained. It becomes extremely difficult, and when trying to replace a label, it becomes difficult to replace the label with a fake one and to make the fake adherent look genuine because the label is destroyed.

(Example 2)

As a substrate, a PET film (E-500, manufactured by Toyobo Co., Ltd.) with a width of 160 mm and a thickness of 50 xm, which has not been subjected to any surface treatment, is prepared, and then a concealing layer is formed. Ink coating liquid (PANNECO, manufactured by Toyo Ink Manufacturing Co., Ltd.) for preparation.

Then, a black ink coating liquid is applied on the substrate by a gravure plate so as to have a thickness of 2.5 m after drying, and a convex character and a blank character are provided to form a masking layer (masking). Step of forming a layer).

Separately, a coating liquid that is applied to the back surface of the base material to form the liquid crystal layer is prepared. The following mixed coating liquid is used as the liquid crystal layer forming coating liquid.

Nematic liquid crystal having acrylyl groups at both terminals (Paliocolor LC242 from BASF) 55.3% by weight

Chiral compound (Paliocolor LC756 from BASF) · · · 2.9% by weight UV polymerization initiator (Cibas Specialty-Irgacure 3 from Chemicals) 69) · · · 1.8% by weight

Methyl ethyl ketone (MEK) as a solvent---40.0% by weight Then, a coating liquid for forming a liquid crystal layer is applied with a gravure plate over the entire back surface of the base material so as to cover the concealing layer. A liquid crystal layer having an average thickness of 3 after coating is formed. Other than the above, that is, the steps of forming the background layer and forming the adhesive layer were performed in the same manner as in Example 1 to form a liquid crystal label.

The resulting liquid crystal label exhibited the same effects as in Example 1. FIG. 5 is an illustrative sectional view of a liquid crystal label according to still another embodiment of the present invention.

The liquid crystal label 210 shown in FIG. 5 is formed on the transparent or translucent base material 212 and the back side of the base material 212 similarly to the liquid crystal labels 10 and 110 described above. Liquid crystal layer 2 14, a background layer 2 16 formed on the surface of the liquid crystal layer 2 14 opposite to the substrate 2 12, and a liquid crystal layer 2 14 side of the background layer 2 16 Consists of an adhesive layer 218 formed on the back surface on the opposite side, and a separation layer 220 is temporarily attached to the surface of the adhesive layer 218.

Therefore, the liquid crystal label 210 has the same effect as the liquid crystal labels 10 and 110 described above.

In the liquid crystal label 210, the liquid crystal layer 214 is formed on the back side of the base member 212, for example, at a portion excluding a ring-shaped portion.

Further, in the liquid crystal label 210, the background layer 216 is formed on the back side of the base member 212 so as to cover the liquid crystal layer 214. The background layer 2 16 includes a main portion 2 16 a and image portions 2 16 b and 2 16 c. The image portion 2 16 b of the background layer 2 16 is formed linearly on the surface of the liquid crystal layer 2 14 opposite to the substrate 2 12. In addition, the image portion 2 16 c of the background layer 2 16 corresponds to the surface of the liquid crystal layer 2 14 opposite to the surface opposite to the substrate 2 12. It is formed linearly across the back surface of 2 12. Further, the main portion 2 16 a of the background layer 2 16 is formed so as to cover the liquid crystal layer 2 14 and the image portions 2 16 b and 2 16 c on the back side of the substrate 2 12. It is formed.

The background layer 2 16 is formed such that the infrared absorption of the image portions 2 16 b and 2 16 c is larger than the infrared absorption of the main portion 2 16 a.

Further, the background layer 2 16 has a small color difference E * ab in the visible region between the main portion 2 16 a and the image portions 2 16 b and 2 16 c, and the main portion 2 16 a under visible light. It is difficult to distinguish between 16a and the image parts 2 16b and 2 16c, and the image parts 2 16b and 2 16c are configured so that they cannot be identified under visible light. As the material of the main portion 211a of the 216, for example, non-carbon ink is used. As the non-strength ink, for example, the following UV curing type ink is used.

T & K 丁〇 Eight companies' 1; ¥ KS T S L F L resistant ink

Further, as the material of the image portions 2 16 b and 2 16 c of the background layer 2 16, for example, ink containing carbon black is used. As the carbon black ink, for example, the following UV curable ink is used.

T & K TOKA No. 5 B F Ink O S

As described above, in order to configure the image portions 2 16 b and 2 16 c of the background layer 2 16 so as not to be identified under visible light, the main portion 2 16 of the background layer 2 16 It is preferable that the color difference E * ab in the visible region between a and the image portions 2 16 b and 2 16 c be 6 or less, and it is more preferable that the color difference E * ab be 3 or less.

The liquid crystal label 210 shown in Fig. 5 has a flat surface when viewed under visible light. As shown in the schematic view of FIG. 6, the liquid crystal layer 214 having glitter can be seen through the base material 212, and the background layer 212 can be seen in a portion where the liquid crystal layer 214 does not exist. 6 looks like a black ring.

In addition, the liquid crystal label 210 shown in Fig. 5 irradiates the surface of the liquid crystal label 210 with infrared rays in the dark and reflects the light reflected from the surface side of the liquid crystal label 210 into a CCD camera. As shown in Fig. 7, the image portions of the background layer 2 16b and 2 16c are dark as shown in Fig. 7 when the image captured in the power camera DCR-PC120 is used in night shot mode. Visible, other parts appear bright.

Therefore, in the liquid crystal label 210, the accuracy of the determination of the label authenticity can be further improved as compared with the liquid crystal labels 10 and 110 described above.

In addition, in the liquid crystal label 210, the image portions 2 16b and 2 16c of the background layer 2 16 are formed in three straight lines, but the number of image portions of the background layer is The shape may be arbitrarily changed to 1, 2 or 4 or more, and the shape of the object portion of the background layer may be arbitrarily changed to a character shape, a figure shape, a symbol shape, or the like.

Also, in the liquid crystal label 210, the infrared absorption of the image portions 216b and 216c is larger than the infrared absorption of the main portion 216a of the background layer 216. However, the infrared absorption of the main part 216a is larger than the infrared absorption of the image parts 216b and 216c of the background layer 216. May be formed. In this case, in the above-mentioned image of the CCD camera, the main portion 2 16 a of the background layer 2 16 becomes dark, and the image portions 2 16 b and 2 16 c of the background layer 2 16 become bright.

In the liquid crystal label 210, the main portion 211a of the background layer 216 is positioned on the surface opposite to the substrate 212 in the image portions 216b and 216c. May not be formed. Thus, the strokes 2 1 6 b and The same effect can be obtained even if the main portion 2 16 a of the background layer 2 16 is not formed on 2 16 c.

Also, in this liquid crystal label 210, the entire main surface portion 2 16a of the background layer 2 16 is made of carbon black without forming the image portions 2 16 b and 2 16 c of the background layer 2 16 It may be formed of ink or non-carbon ink. If the entire surface portion 2 16a of the background layer 2 16 is made of carbon black in this way, the entire image obtained by the CCD camera described above becomes dark, and the main surface portion 2 16 a of the background layer 2 16 If the whole is formed with non-power, the whole image with the above-mentioned CCD camera becomes bright.

Further, in the liquid crystal label 210, a part of the background layer 216 may be formed of non-inking, and the remaining part may be formed of carbon-ink. For example, if the right half of the background layer 2 16 of the liquid crystal label 210 is made of non-carbon, and the left half is made of carbon, the above-mentioned image from the CCD camera will be bright on the right half and left half on the CCD camera. Becomes longer.

Further, in this liquid crystal label 210, the color difference E * ab in the visible range between the main part 2 16a of the background layer 2 16 and the image parts 2 16b and 2 16c is set to exceed 6. It may be. In this case, the image portions 2 16 b and 2 16 c of the background layer 2 16 can be easily identified under visible light. When the light is received, the difference in the absorptivity of infrared rays between the main part 2 16a of the background layer 2 16 and the image parts 2 16b and 2 16c can be clearly seen. , 110, the accuracy of label authenticity determination can be improved.

Note that, similarly to the above-described liquid crystal labels 10 and 110, this liquid crystal label 210 is also attached to a genuine product and then peeled off from the product. In addition, in order to prevent peeling between the layers or destruction of some layers and replacement with a fake, the following configuration may be adopted. That is, in each of the above-described liquid crystal labels, the adhesive strength between the base material and the liquid crystal layer is lower than the adhesive strength between the liquid crystal layer and the background layer, lower than the adhesive strength between the background layer and the adhesive layer, and It is preferable that the adhesive layer is configured to be weaker than the cohesive failure strength of each layer. With this configuration, when the liquid crystal label is peeled off, the liquid crystal label is peeled off between the base material and the liquid crystal layer, so that the whole is not peeled off well and reattachment can be prevented.

Alternatively, in each of the above-described liquid crystal labels, the cohesive failure strength of the liquid crystal layer, the background layer, and the adhesive layer of the liquid crystal layer and the Z or the background layer is determined by the other layers of the liquid crystal layer, the background layer, and the adhesive layer. It is preferable to be configured to be weaker than the cohesive failure strength, weaker than the adhesive strength between the substrate and the liquid crystal layer, weaker than the adhesive strength between the liquid crystal layer and the background layer, and weaker than the adhesive strength between the background layer and the adhesive layer. With this configuration, when the liquid crystal label is peeled off, the liquid crystal layer and Z or the background layer are broken, and the whole is not peeled off properly, so that re-sticking can be prevented.

Alternatively, in each of the above-mentioned liquid crystal labels, the adhesive strength between the respective layers, for example, the adhesive strength between the base material and the liquid crystal layer, the adhesive strength between the liquid crystal layer and the background layer, the adhesive strength between the background layer and the adhesive layer, and the adhesive layer It is preferable that at least one of the cohesive fracture strength of each layer except for the cohesive fracture strength of the liquid crystal layer and the cohesive fracture strength of the background layer is weaker than that of the adhesive layer. With this configuration, when the liquid crystal label is peeled off, it peels between the layers and / or the liquid crystal layer and / or the background layer is broken, preventing the whole from being peeled off properly and preventing re-sticking. can do. In this case, the adhesive strength between the layers, for example, the adhesive strength between the substrate and the liquid crystal layer, the adhesive strength between the liquid crystal layer and the background layer, the adhesive strength between the background layer and the adhesive layer, and the cohesive failure of each layer except the adhesive layer Strength, for example, two or more of the cohesive fracture strength of the liquid crystal layer and the cohesive fracture strength of the background layer Etc. may be formed.

In addition, the convex characters and the blank characters in each of the above liquid crystal labels can be formed by using gravure printing, flexographic printing, letterpress printing, screen printing, etc. Among them, gravure printing and flexographic printing are used in Is preferred because it is easy to form on the clear, and more preferably, it is formed by gravure printing.

In addition, the image portions 2 16 b and 2 16 c of the background layer 2 16 in the liquid crystal label 210 shown in FIG. 5 were also subjected to gravure printing, flexographic printing, letterpress printing, screen printing, and the like. Of these, gravure printing and flexographic printing are preferred among these, because they make it easier to form clear images, and more preferably gravure printing.

Further, the entire surface coating (solid) may be formed by any of the printing methods described above, and may be further applied by a method such as a knife coater or a bar coater.

In the description of the above embodiment, a label continuous body in which a plurality of labels are formed on a separator is described. However, the separator is not temporarily attached to the surface of the adhesive layer made of an adhesive, and the liquid crystal layer of the base material is not attached. On the surface on the side opposite to the side, apply a material with excellent releasability such as silicone to form a release layer, wind it with the adhesive layer inside and the surface with the base material release layer formed outside. It may be a continuous label that can be rewound for use.

Industrial applicability

According to the present invention, a liquid crystal label, a liquid crystal, a liquid crystal label, and a liquid crystal, which can be easily attached along the surface of an adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. A label continuum and a method for producing the same can be provided.

Claims

The scope of the claims

1. a transparent or translucent substrate;

A liquid crystal layer formed on the back side of the base material,

A liquid crystal label, comprising: a background layer formed on a surface of the liquid crystal layer opposite to the base material; and an adhesive layer formed on a surface of the background layer opposite to the liquid crystal layer.

2. The liquid crystal label according to claim 1, wherein the liquid crystal layer contains a liquid crystal composition comprising a cholesteric phase.

3. The liquid crystal label according to claim 1, wherein the liquid crystal layer is partially formed on a back surface of the base material.

3. The concealing layer is formed partially on the back surface of the base material, and the liquid crystal layer is formed on the back surface of the base material so as to cover the concealing layer. LCD label.

5. The liquid crystal label according to any one of claims 1 to 4, wherein the background layer has a portion having a difference in absorptivity of infrared rays.

6. The liquid crystal label according to claim 5, wherein a portion of the background layer having a difference in infrared absorptance is configured not to be identified under visible light.

7. The cohesive failure strength of at least one of the adhesive strength between each layer and the cohesive failure strength of each layer excluding the adhesive layer is smaller than the cohesive failure strength of the adhesive layer. The liquid crystal label described in any of them.

8. The adhesive strength between the base material and the liquid crystal layer is lower than the adhesive strength between the liquid crystal layer and the background layer, the adhesive strength between the background layer and the adhesive layer, and the liquid crystal layer and the background layer. The liquid crystal label according to claim 7, wherein the liquid crystal label is configured to be weaker than the cohesive failure strength of each layer of the adhesive layer.

9. The liquid crystal layer among the liquid crystal layer, the background layer, and the adhesive layer, And Z or the cohesive failure strength of the background layer is weaker than the cohesive fracture strength of the liquid crystal layer, the background layer, and the other layer of the adhesive layer, and is smaller than the adhesive strength between the base material and the liquid crystal layer. 8. The liquid crystal label according to claim 7, wherein the liquid crystal label is weaker than the adhesive strength between the liquid crystal layer and the background layer, and weaker than the adhesive strength between the background layer and the adhesive layer.

10. Adhesive strength between the base material and the liquid crystal layer, adhesive strength between the liquid crystal layer and the background layer, adhesive strength between the background layer and the adhesive layer, cohesive failure strength of the liquid crystal layer, and the background layer The liquid crystal label according to claim 7, wherein at least one of the cohesive failure strengths of the liquid crystal label is configured to be weaker than the cohesive failure strength of the adhesive layer.

1 1. A base material having transparency or translucency, the surface of which has releasability, and a liquid crystal layer formed on the back side of the base material,

A background layer formed on a surface of the liquid crystal layer opposite to the substrate, and an adhesive layer formed on a surface of the background layer opposite to the liquid crystal layer;

A liquid crystal label continuum wound with the surface of the base material outside and the adhesive layer inside.

1 2. The label is

A transparent or translucent substrate,

A liquid crystal layer formed on the back side of the base material,

The liquid crystal label continuum, wherein the label is temporarily attached to a separator on a surface of the adhesive layer opposite to the background layer.

1 3. Form a liquid crystal layer on the back side of a transparent or translucent substrate. And steps

A liquid crystal label comprising: a step of forming a background layer on a surface of the liquid crystal layer opposite to the substrate; and a step of forming an adhesive layer on a surface of the background layer opposite to the liquid crystal layer. Production method.

1 4. The step of forming the liquid crystal layer comprises:

14. A step of applying a liquid crystal layer-forming coating solution and heating to a temperature at which a cholesteric phase can be formed, forming a cholesteric phase, irradiating ultraviolet rays, and UV-crosslinking to fix the cholesteric phase. 3. The method for producing a liquid crystal label according to item 1.