JPWO2004032099A1 - Liquid crystal label, liquid crystal label continuous body, and method for producing liquid crystal label continuous body - Google Patents

Abstract

A liquid crystal label, a liquid crystal label continuous body, and a method for producing the same, which are flexible and easy to stick along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery I will provide a. The liquid crystal label (10) of the present invention comprises a transparent or translucent substrate (12), a liquid crystal layer (14) formed on the back side of the substrate (12), and a base of the liquid crystal layer (14). A background layer (16) formed on the surface opposite to the material (12) and an adhesive layer (18) formed on the surface of the background layer (16) opposite to the liquid crystal layer (14). Become. The method for producing a liquid crystal label according to the present invention comprises a step of forming a liquid crystal layer on the back side of a transparent or translucent substrate, and a step of forming a background layer on the surface of the liquid crystal layer opposite to the substrate. And a step of forming an adhesive layer on the surface of the background layer opposite to the liquid crystal layer.

Description

  The present invention relates to a liquid crystal label, a liquid crystal label continuum, and a method for manufacturing a liquid crystal label, and more particularly to a liquid crystal label suitable for use as a label that can prevent forgery, a liquid crystal label continuum, and a method for manufacturing the same.

Conventionally, the recording layer of the label has been formed by thermal recording, thermal color development, printing, etc., so it is relatively easy to make a fake label. I have. In addition, a label using a material that emits light when irradiated with ultraviolet rays, infrared rays, or the like can be recognized as a fake only by irradiating ultraviolet rays or infrared rays, and it is difficult to determine authenticity only by visual observation.
In view of this, there has been proposed a label capable of authenticity identification, such as an authenticity identification label disclosed in JP-A-2002-205471.
This conventional authenticity distinguishable label uses a display material containing a cholesteric liquid crystal pigment, which is rarely used as a display material of the conventional label. Therefore, if there is no knowledge of these materials, the function of the material is exhibited. For this reason, it is suitable as an anti-counterfeit label because it is difficult to forge.
However, since it is difficult to realize the object of the invention, the cost of the label increases, and for example, it is not suitable for use as an anti-counterfeit label for a low-priced part, and is not flexible. That is, on a layer such as a liquid crystal layer, a microsphere transparent bead having a diameter of 10 to 100 μm, preferably 50 μm or less, preferably a glass (hard) bead, while the layer still does not lose its adhesiveness. It is difficult to control because it must be formed in a single layer so that it does not overlap evenly, preferably two or more layers, so there is a problem in the reproducibility of manufacturing, and the yield must be reduced. Costs are rising and flexibility is insufficient.
Therefore, those that do not employ the operation of aligning the microbeads or the operation of laminating other layers with the liquid crystal layer having a sticky state can produce a label with the same performance with high reproducibility, good yield, and relatively It is easy to manufacture an anti-counterfeit label that can be manufactured at a low cost and that can be immediately distinguished from a general-purpose label only by changing the viewing direction and observing the label.
Therefore, the main object of the present invention is to provide a liquid crystal that is flexible, easy to stick along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. It is to provide a label, a liquid crystal label continuous body, and a production method thereof.

The liquid crystal label according to claim 1 of the present invention is a transparent or translucent base material, a liquid crystal layer formed on the back surface side of the base material, and a surface of the liquid crystal layer opposite to the base material. The liquid crystal label includes a formed background layer and an adhesive layer formed on a surface of the background layer opposite to the liquid crystal layer.
A liquid crystal label according to a second aspect of the present invention is the liquid crystal label according to the first aspect, wherein the liquid crystal layer contains a liquid crystal composition comprising a cholesteric phase.
The liquid crystal label according to claim 3 according to the present invention is the liquid crystal label according to claim 1 or 2, wherein the liquid crystal layer is partially formed on the back surface of the substrate.
The liquid crystal label according to claim 4 according to the present invention is such that a concealing layer is partially formed on the back surface of the base material, and a liquid crystal layer is formed on the back surface of the base material so as to cover the concealing layer. The liquid crystal label according to claim 1 or claim 2.
A liquid crystal label according to a fifth aspect of the present invention is the liquid crystal label according to any one of the first to fourth aspects, wherein the background layer has a portion having a difference in infrared absorption rate.
The liquid crystal label according to claim 6 according to the present invention is the liquid crystal label according to claim 5, wherein a portion provided with a difference in infrared absorption rate in the background layer is configured not to be identified under visible light. is there.
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.
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 weaker than the adhesive strength between the liquid crystal layer and the background layer, and is weaker than the adhesive strength between the background layer and the adhesive 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 of the layer, the background layer, and the adhesive layer.
According to a ninth aspect of the present invention, in the liquid crystal label, the cohesive failure strength of the liquid crystal layer and / or the background layer of the liquid crystal layer, the background layer and the adhesive layer is Less than the cohesive fracture 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.
According to a tenth aspect of the present invention, there is provided the liquid crystal label according to the present invention, wherein 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, the cohesive failure strength of the liquid crystal layer, and The liquid crystal label according to claim 7, wherein at least one of the cohesive failure strength of the background layer is weaker than the cohesive failure strength of the adhesive layer.
The liquid crystal label continuous body according to claim 11 according to the present invention has transparency or translucency, and a surface thereof has a peelability, a liquid crystal layer formed on the back side of the substrate, It includes a background layer formed on the surface of the liquid crystal layer opposite to the substrate and an adhesive layer formed on the surface of the background layer opposite to the liquid crystal layer, with the surface of the substrate facing outside and bonding It is a liquid crystal label continuous body wound with the agent layer inside.
The liquid crystal label continuous body according to claim 12 according to the present invention includes: a base material having a transparent or translucent label; a liquid crystal layer formed on the back side of the base material; and a base material of the liquid crystal layer. A background layer formed on an opposite surface and an adhesive layer formed on a surface opposite to the liquid crystal layer of the background layer, and the label is formed on the surface of the adhesive layer opposite to the background layer. The liquid crystal label continuous body temporarily attached to the separator.
According to a thirteenth aspect of the present invention, there is provided a method for producing a liquid crystal label, comprising: forming a liquid crystal layer on the back side of a transparent or translucent substrate; and forming a liquid crystal layer on a surface opposite to the substrate. A method for producing a liquid crystal label, comprising: forming a background layer; and forming an adhesive layer on a surface of the background layer opposite to the liquid crystal layer.
In the method for producing a liquid crystal label according to claim 14 of the present invention, the step of forming the liquid crystal layer is performed by heating the cholesteric phase to a temperature at which the cholesteric phase can be formed by applying the liquid crystal layer forming coating liquid. The method for producing a liquid crystal label according to claim 13, comprising the step of forming and fixing the cholesteric phase by UV irradiation and UV crosslinking.
The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the embodiments of the present invention with reference to the drawings.

FIG. 1 is a cross-sectional schematic 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 producing a label continuum.
FIG. 4 is an illustrative sectional view of a liquid crystal label according to another embodiment of the present invention.
FIG. 5 is a cross-sectional schematic view of a liquid crystal label according to still another embodiment of the present invention.
FIG. 6 is an illustrative 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 the reflected light from the surface side of the liquid crystal label is captured by a CCD camera.

（表１の注）表１の相転移温度の欄において、Ｃは結晶性固体、Ｓはスメクチック相、Ｓｃ^＊はキラルスメクチックＣ相、Ｃｈはコレステリック相、Ｎ^＊はキラルネマチック相、Ｉは等方性液体を表す。
また、表２に示す単独でネマチック相を示す化合物に、表３に示すキラル化合物を加えてもキラルネマチック相を形成する（以下、コレステリック相、キラルネマチック相の区別をせずに、コレステリック相と総称する）。

（表２の注）表２の相転移温度の柵において、Ｃは結晶性固体、Ｎはネマチック相、Ｉは等方性液体を表す。

（表３の注）ネマチック相を示す液晶にキラル分子を添加すると、キラルネマチック相（Ｎ^＊）が得られる。この場合、その混合液晶のピッチの逆数１／ｐは、キラル分子のモル濃度ｘ_Ｂが小さい領域では、ｘ_Ｂに比例する。それゆえ、１／ｐｘ_Ｂのことを、キラルのねじり力という。
この発明にかかる液晶層１４は、コレステリック相が固定されたものであり、その固定の方法としては、たとえば、液晶分子の両末端にアクリル基を有さしめ、これを基材１２に塗工し、この塗工物をコレステリック相を形成し得る温度まで加熱し、コレステリック相を形成し、紫外線照射をすることにより、ＵＶ架橋してコレステリック相を固定する。
そのため、温度等、環境が変化しても、コレステリック相は安定して存在する。
あるいは、液晶分子と一般的に用いられるバインダーの混合物を塗工し、コレステリック相を形成し得る温度に加熱し、コレステリック相を形成し、乾燥し、バインダーでコレステリック相を固定してもよい。
液晶層形成用塗液は、溶剤系でも非溶剤系でもよい。
溶剤系では、溶剤としてＭＥＫ，ＭＩＢＫ等のケトン類、トルエン、酢酸エチル等が好ましい。また、固形分濃度は、特に制限はないが、２５〜６７％が好ましい。２５％を下回ると、画線を鮮明に形成できなくなるおそれがあり、乾燥に要する時間が長くなる。６７％を超えると塗液を加熱しないと固体が析出するおそれがある。特に好ましい濃度範囲は、５０〜６５％である。塗液からの溶剤の蒸発等による固体の析出のおそれをなくすために、塗液を加熱しながら塗工することも行われる。
非溶剤系では、塗工組成物をコレステリック相を形成する最低温度以上、好ましくはコレステリック相を形成する温度領域の温度に加熱しながら塗工を行う。
溶剤系でも、非溶剤系でも、塗工物に形成されているコレステリック相の固定を行うため、コレステリック相を形成する温度範囲に液晶層形成用塗工物を保ったまま、架橋等を行う。これによって、コレステリック相は、温度環境等が変わっても、たとえば常温においても安定的に維持される。
コレステリック相からなる液晶層１４は、光輝性を示し、見る方向によって連続的に色調が変化する。たとえば、上から垂直に見たときにはグリーンに見え、水平に近い方向に見たときにはブルーに見えるといった如くである。
このコレステリック相を示す液晶層１４は、広いスペクトル領域で入射する光の一部の波長領域のみが反射し、これ以外の領域の波長は、すべて透過するという特徴を有する。
この液晶層１４は、基材１２の裏面に全面にわたって形成されるのではなく、文字、絵等からなる画線が、液晶層１４を形成する液晶層形成用塗液を塗工して凸文字や抜き文字が形成されることによって、画線を構成するように形成されている。
なお、螺旋のピッチＰ（第２図図示）が大きくなると、長波長側の色が現われ、螺旋のピッチＰが小さくなると、短波長側の色が現われる。このピッチを変えるには、キラル化合物を添加した系においては、キラル化合物の添加量を変更すればよい。
背景層１６は、墨インキや赤、青等の着色インキ等を印刷・塗工することによって形成される。背景層１６は、液晶層１４の光輝性を際立たせるために形成されたもので、液晶層１４を覆うように基材１２の裏面全面にわたって形成されている。特に、背景層１６としては、墨インキ等で形成された黒色が、液晶層１４の光輝性を際立たせるために優れている。
また、背景層１６の色彩によって、液晶層１４の目視での色調が変化するので、背景層１６を形成するインキの組成や色が重要である。たとえば、背景層１６の色が黒のときは、液晶層１４を目視すると、グリーンからブルーの光輝性を示すのに対し、背景層１６が赤のときは、液晶層１４を目視すると、オレンジから紫の光輝性を示し、また、背景層１６が白に近い着色のときには、液晶層１４は、乳白色またはパール調を示す。
したがって、背景層１６を形成する色を２以上に区分けして形成すると、液晶層１４を目視したとき、背景層１６の色彩の変化に対応した彩り鮮やかな液晶ラベルとなる。
接着剤層１８は、アクリル系、ゴム系等の一般的な粘着剤が塗布されて形成されている。
接着剤層１８の表面には、紙等の表面にシリコーン等の剥離剤が塗工されてなるセパレータ２０が仮着されている。
被貼着体に貼付けられた液晶ラベル１０を被貼着体から剥がそうとしたとき、液晶ラベル１０が破壊して偽物のラベルに貼り替えられないようにするために、たとえば、次のような構成としてもよい。
基材１２と液晶層１４の接着強度を、他の層間の接着強度、すなわち第１図の場合は液晶層１４と背景層１６間および背景層１６と接着剤層１８間の接着強度、および各層の凝集破壊強度より弱く構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、基材１２と液晶層１４との接着強度を調整する方法がある。
また、背景層１６および／または液晶層１４の凝集破壊強度を、他の層の凝集破壊強度および各層間の接着強度より弱く構成してもよい。
このようにすれば、基材１２と液晶層１４との間で層間剥離をしたり、背景層１６および／または液晶層１４において、凝集破壊し、液晶ラベル１０を被貼着体から剥がそうとしたとき、液晶ラベル１０が破壊して、他の偽物の品物にラベルを貼り替え、偽物を真正品と見せかけることができなくなる。FIG. 1 is a cross-sectional schematic view of a liquid crystal label according to an embodiment of the present invention.
The liquid crystal label 10 is a liquid crystal in which a base 12 made of a synthetic resin sheet or film such as a transparent or translucent polyester film or the like, and a cholesteric liquid crystal formed on the back side of the base 12 are fixed. A layer 14, a background layer 16 formed on the surface of the liquid crystal layer 14 opposite to the substrate 12, and formed to highlight the glitter of the liquid crystal layer 14, and the liquid crystal layer of the background layer 16 It consists of an adhesive layer 18 formed by applying an adhesive or the like formed on the surface opposite to the 14 side.
As the base material 12, it is suitable to use a plastic film such as transparent PET, a sheet or the like. In particular, the surface of the base material 12 on the side on which the liquid crystal layer 14 is formed (that is, the surface of the base material 12) is transparent. In addition, when the liquid crystal label 10 is to be peeled off from the adherend, it is desirable that the liquid crystal layer 14 is excellent in smoothness so that the liquid crystal layer 14 can be easily delaminated. Furthermore, in order to facilitate delamination between the substrate 12 and the liquid crystal layer 14, it is desirable that the surface side on which the liquid crystal layer is formed is not subjected to surface treatment. Sometimes, fine linear marks may be 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 alignment of liquid crystal molecules constituting the liquid crystal layer 14.
A cholesteric liquid crystal is selected as the liquid crystal composition constituting the liquid crystal layer 14, and the cholesteric liquid crystal is formed by coating a compound having a helical cholesteric phase or a chiral nematic phase (see FIG. 2).
Examples of compounds exhibiting a cholesteric phase or a chiral nematic phase include those shown in Table 1 in addition to cholesteryl nonanoate, cholesteryl myristate, and the like.

(Note to Table 1) In the column of phase transition temperature in Table 1, C is a crystalline solid, S is a smectic phase, Sc ^* is a chiral smectic C phase, Ch is a cholesteric phase, N ^* is a chiral nematic phase, I is etc. Represents an isotropic liquid.
Further, a chiral nematic phase can be formed by adding a chiral compound shown in Table 3 to a compound showing a nematic phase alone shown in Table 2 (hereinafter, without distinguishing between a cholesteric phase and a chiral nematic phase, Generically).

(Note to Table 2) In the fence of the phase transition temperature shown in Table 2, C represents a crystalline solid, N represents a nematic phase, and I represents an isotropic liquid.

(Note to Table 3) When a chiral molecule is added to a liquid crystal showing a nematic phase, a chiral nematic phase (N ^* ) is obtained. In this case, the reciprocal 1 / p the pitch of the mixed liquid crystals, the molar concentration x _B of chiral molecules in a small area, is proportional to x _B. Therefore, 1 / px _B is called chiral torsional force.
The liquid crystal layer 14 according to the present invention has a cholesteric phase fixed. As a fixing method, for example, an acrylic group is provided at both ends of liquid crystal molecules, and this is applied to the substrate 12. The coated product is heated to a temperature at which a cholesteric phase can be formed, a cholesteric phase is formed, and UV irradiation is performed by UV irradiation to fix the cholesteric phase.
Therefore, the cholesteric phase exists stably even if 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 formed, dried, and the cholesteric phase fixed with a binder.
The liquid crystal layer forming coating solution may be solvent-based or non-solvent-based.
In the solvent system, ketones such as MEK and MIBK, toluene, ethyl acetate and the like are preferable as the solvent. The solid content concentration is not particularly limited, but is preferably 25 to 67%. If it is less than 25%, the image line may not be formed clearly, and the time required for drying becomes longer. If it exceeds 67%, solids may be deposited unless the coating liquid is heated. A particularly preferred concentration range is 50 to 65%. In order to eliminate the possibility of solid precipitation due to evaporation of the solvent from the coating liquid, coating is also performed while heating the coating liquid.
In the non-solvent system, coating is performed while heating the coating composition to a temperature above the minimum temperature at which the cholesteric phase is formed, preferably at a temperature in the temperature range where the cholesteric phase is formed.
In order to fix the cholesteric phase formed in the coated product, both in the solvent system and in the non-solvent system, crosslinking or the like is performed while keeping the liquid crystal layer-forming coated product in the temperature range in which the cholesteric phase is formed. Thus, the cholesteric phase is stably maintained even at a normal temperature, for example, even if the temperature environment changes.
The liquid crystal layer 14 composed of a cholesteric phase exhibits glitter, and the color tone changes continuously depending on the viewing direction. For example, it looks green when viewed vertically from above, and appears blue when viewed in a horizontal direction.
The liquid crystal layer 14 exhibiting the cholesteric phase has a characteristic that only a part of the wavelength region of light incident in a wide spectral region is reflected and all the wavelengths in other regions are transmitted.
The liquid crystal layer 14 is not formed on the entire back surface of the substrate 12, but an image line composed of characters, pictures, etc. is applied by applying a liquid crystal layer forming coating liquid to form the liquid crystal layer 14. By forming a blank character, the image line is formed.
When the spiral pitch P (shown in FIG. 2) is increased, the color on the long wavelength side appears, and when the spiral pitch P is decreased, the color on the short wavelength side appears. In order to change this pitch, the addition amount of the chiral compound may be changed in the system to which the chiral compound is added.
The background layer 16 is formed by printing / coating with black ink or colored ink such as red and blue. The background layer 16 is formed to make the glitter of the liquid crystal layer 14 stand out, 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, black formed with black ink or the like is excellent for making the glitter of the liquid crystal layer 14 stand out.
Further, since the visual color tone of the liquid crystal layer 14 changes depending on the color of the background layer 16, the composition and color of the ink forming the background layer 16 are important. For example, when the color of the background layer 16 is black, when the liquid crystal layer 14 is visually observed, green to blue glitter is exhibited, whereas when the background layer 16 is red, the liquid crystal layer 14 is visually observed from orange. When the background layer 16 is colored near white, the liquid crystal layer 14 is milky white or pearly.
Therefore, when the colors forming the background layer 16 are divided into two or more, when the liquid crystal layer 14 is viewed, a colorful liquid crystal label corresponding to the color change of the background layer 16 is obtained.
The adhesive layer 18 is formed by applying a general adhesive such as acrylic or rubber.
On the surface of the adhesive layer 18 is temporarily attached a separator 20 formed by coating a release agent such as silicone on the surface of paper or the like.
In order to prevent the liquid crystal label 10 from being broken and replaced with a fake label when the liquid crystal 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 other layers, that is, the adhesive strength between the liquid crystal layer 14 and the background layer 16 and between the background layer 16 and the adhesive layer 18 in the case of FIG. The composition is weaker than the cohesive fracture strength. As the method, for example, there is a method of adjusting the adhesive strength between the substrate 12 and the liquid crystal layer 14 without using any binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
Further, the cohesive failure strength of the background layer 16 and / or the liquid crystal layer 14 may be configured to be weaker than the cohesive failure strength of other layers and the adhesive strength between the layers.
If it does in this way, delamination between the base material 12 and the liquid-crystal layer 14 will be carried out, the cohesive failure will be carried out in the background layer 16 and / or the liquid-crystal layer 14, and it will try to peel off the liquid-crystal label 10 from a to-be-adhered body. In this case, the liquid crystal label 10 is destroyed, and the label is pasted on another counterfeit item, making it impossible to make the counterfeit item appear to be a genuine item.

As a base material, a surface-treated PET film having a width of 160 mm and a thickness of 50 μm (E-5000 manufactured by Toyobo Co., Ltd.) is prepared and separately applied to the back surface of the base material to form a liquid crystal layer. Prepare the coating solution.
As the liquid crystal layer forming coating solution, the following mixed coating solution is used.
Nematic liquid crystal having acrylic groups at both ends (PALIOcolor LC242 from BASF) ... 55.3% by weight
Chiral compound (PALIOcolor LC756 from BASF) ... 2.9% by weight
UV polymerization initiator (Irgacure 369 from Ciba Specialty Chemicals) ... 1.8% by weight
Methyl ethyl ketone (MEK) as solvent: 40.0% by weight
With this liquid crystal forming coating liquid, a gravure plate is applied so that the thickness after drying is 3 μm so as to form an image line of convex letters and blank letters including a pattern, and a drying zone ( 110-120 ° C) for 15 seconds to dry and form a cholesteric phase. Immediately thereafter, ultraviolet irradiation is performed to perform ultraviolet UV curing to fix the cholesteric phase. The temperature for forming the nematic liquid crystal is 59 ° C. or higher and 120 to 124 ° C. or lower.
Thereby, a liquid crystal layer composed of a stable cholesteric phase is formed on the substrate (step of forming a liquid crystal layer).
Next, a black ink coating liquid (PANE ECO manufactured by Toyo Ink Manufacturing Co., Ltd.) for forming the background layer is prepared, and this black ink coating liquid is coated on the back surface of the substrate with a gravure plate so as to cover the liquid crystal layer. It coats so that it may become the average thickness of 3 micrometers after drying. Thereafter, the black ink coating liquid is dried by passing through a drying zone (70 to 80 ° C.) for 3 seconds.
Thus, a background layer covering the liquid crystal layer is formed on the back surface of the substrate (step of forming the background layer).
Next, the surface of the separator coated with a release agent such as silicone on the surface of the paper, separately prepared by applying a pressure-sensitive adhesive, and the back side of the background layer formed on the back side of the substrate The surface of the adhesive layer formed on the surface of the separator is opposed to each other, and the two are passed between the lamination rollers to be laminated (step of forming the adhesive layer).
Furthermore, in order to form a laminate in which a laminate comprising the substrate, the liquid crystal layer and the background layer and a laminate of an adhesive layer and a separator are laminated into an appropriately sized label (20 × 70 mm), The die is cut so as to reach the adhesive layer side surface of the separator from the surface side. In this manner, after forming a predetermined label shape, the residue is removed by removing unnecessary residue other than the label from the separator surface.
As shown in FIG. 3, the labels are formed in six rows at a constant interval (6 mm interval) in the width direction of the separator, and the labels in each column are fixed intervals (in the longitudinal direction of the separator ( Are arranged at intervals of 3 mm). Therefore, between the labels arranged in six rows in the width direction, the separators are slit at equal intervals, the separators are divided into six, and the labels are continuously provided at predetermined intervals on the surface of each separator. An ordered label continuum was created.
In addition, you may change suitably the shape of this label and the space | interval between labels.
When viewed from the base material side, the liquid crystal label of this example showed vivid luster that changed from green to blue-violet depending on the viewing direction.
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 substrate and the liquid crystal layer is Because it is weaker than the adhesive strength between layers and the cohesive failure strength of each layer, it can be attached to an adherend (made of polypropylene) and peeled off without destroying the liquid crystal label attached to the adherend However, it was not possible to peel off the label without destroying it from the substrate and breaking the label from the adherend.
In this example, a binder was not used in the liquid crystal layer forming coating solution. However, even when a small amount of the binder was added, the amount of the binder was suppressed, as described above. The adhesive strength of the interface can be designed to be weaker than the adhesive strength of the interface between other layers and the cohesive failure strength of each layer.
In this embodiment, the liquid crystal layer may be formed on the entire back surface of the substrate. If the liquid crystal layer is formed on the entire back surface of the base material in this way, a liquid crystal label without image lines showing almost uniform glitter can be obtained.
FIG. 4 is an illustrative sectional view showing another embodiment of the liquid crystal label of the present invention.
This liquid crystal label 110 is formed on a substrate 112 having transparency or translucency, a liquid crystal layer 114 formed on the back side of the substrate 112, and a surface of the liquid crystal layer 114 opposite to the substrate 112. Background layer 116, adhesive layer 118 formed on the back surface of background layer 116 opposite to the liquid crystal layer 114 side, and concealing layer 122 partially formed on the back surface of substrate 112. Become.
On the surface of the adhesive layer 118, a separator 120 formed by coating a release agent such as silicone on 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 is provided with a concealing layer 122, and the concealing layer 122 is an ink that forms the background layer 116. It is formed by the same ink. The concealing layer 122 may be translucent as long as it has concealability and the liquid crystal layer 114 cannot be seen through even when viewed from the base material 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, and the cholesteric phase is formed even when the temperature at which the liquid crystal layer 114 is formed is higher or lower. do not do. When the coating film for forming a liquid crystal layer after coating is once heated to a temperature higher than the temperature range in which the cholesteric phase is formed, that is, to the temperature range in which the cholesteric phase is formed after being heated to the liquefaction temperature, the glittering property decreases. In addition, it is preferable that the drying after coating is not heated to the liquefaction temperature. Moreover, in the temperature region where the cholesteric phase is formed, it is advantageous in terms of brightness and the like when the temperature is set as high as possible. This is presumably due to the fact that the orientation (formation) of the cholesteric phase is performed promptly and reliably.
After the cholesteric phase is formed, it is necessary to fix the cholesteric phase by performing crosslinking at a temperature in the cholesteric phase formation temperature region in order to stably maintain the cholesteric phase as it is.
Therefore, the concealing layer 122 that forms the image line is formed with such a black ink without limitation and concealing ink such as red and blue, and the liquid crystal layer 114 is formed between the concealing layer 122 and the background layer 116. The structure formed over the entire surface increases the number of processes by one process compared with the liquid crystal label 10 of the above-described embodiment, but it is easy to form the image line more clearly.
Further, in this embodiment in which the liquid crystal layer is formed on the entire surface, the surface of the liquid crystal layer forming coated material coated on the base material 112 is scratched with, for example, a smoothing bar to apply the coated material. It is also possible to perform a cholesteric phase formation promoting treatment that promotes the formation of a more reliably oriented cholesteric phase by, for example, applying a share to.
Further, the thickness and material of the base material 112 are not particularly limited. However, if the thickness is too thin, it becomes difficult to apply the liquid crystal layer forming coating liquid or the background layer forming coating liquid, and the base material 112 is wrinkled. It is more preferable to have a thickness of about 25 μm or more because it easily enters and deforms. On the contrary, if it becomes too thick, it will be confused, and if it is attached to the surface of a curved surface such as a small part, Since it becomes difficult to wear, about 150 micrometers or less are more preferable.
Further, the background layer 116 and the masking layer 122 only have to be thicker than the thickness at which the masking effect is obtained, for example, preferably 1 μm or more, and more preferably about 2 to 5 μm.
The liquid crystal layer 114 only needs to have a thickness that allows the brightness to be visually recognized, and is preferably about 2 to 5 μm. If the thickness is less than 1 μm, the concentration may be reduced, which is not preferable.
Desirably, when the liquid crystal label 110 is to be peeled off from the adherend, the liquid crystal label 110 is destroyed such that the substrate 112 is peeled off from the liquid crystal layer 114 or the liquid crystal layer 114 is agglomerated. Configure.
That is, when the liquid crystal label 110 is peeled off so as to prevent the label attached to the adherend from being peeled off and attached to another fake adherend, the liquid crystal label 110 is destroyed. The configuration is as follows. Therefore, for example, the following configuration may be used.
The adhesive strength between the substrate 112 and the liquid crystal layer 114 is configured to be weaker than the adhesive strength between other layers and the cohesive failure strength of each layer. As the method, for example, there is a method of adjusting the adhesive strength between the substrate 112 and the liquid crystal layer 114 without using any binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
Further, the cohesive failure strength of the background layer 116 and / or the liquid crystal layer 114 may be configured to be weaker than the cohesive failure strength of the other layers and the adhesive strength between the layers.
In this way, delamination between the base material 112 and the liquid crystal layer 114 or cohesive failure occurs in the background layer 116 and / or the liquid crystal layer 114, and the liquid crystal label 110 is peeled off from the adherend. In this case, the liquid crystal label 110 is destroyed and the label cannot be attached to another fake article.
As described above, the liquid crystal label 110 has a background layer 116 formed on the back surface of the liquid crystal layer 114, so that a label that is close to authenticity cannot be produced by a normal printing technique or copying technique. Even if you have technology, if you do not have knowledge about liquid crystals, especially liquid crystals consisting of cholesteric phase, you can not obtain a stable liquid crystal layer with highly oriented cholesteric phase, so it is very difficult to forge labels, In addition, if the label is to be replaced, the label is destroyed, so it is difficult to replace the label with a fake and make the fake adherend appear to be real.

As a substrate, a surface-treated PET film having a width of 160 mm and a thickness of 50 μm (E-5000 manufactured by Toyobo Co., Ltd.) was prepared, and then a black ink coating liquid (Toyo Ink Manufacturing Co., Ltd. PANN ECO) is prepared.
Then, a black ink coating liquid is applied on the substrate by a gravure plate so that the thickness after drying becomes 2.5 μm, and a convex character and a blank character are provided to form a concealing layer (concealing layer) Forming step).
Separately, a coating liquid is prepared which is applied to the back surface of the base material to constitute the liquid crystal layer.
As the liquid crystal layer forming coating solution, the following mixed coating solution is used.
Nematic liquid crystal having acrylic groups at both ends (PALIOcolor LC242 from BASF) ... 55.3% by weight
Chiral compound (PALIOcolor LC756 from BASF) ... 2.9% by weight
UV polymerization initiator (Irgacure 369 from Ciba Specialty Chemicals) ... 1.8% by weight
Methyl ethyl ketone (MEK) as solvent: 40.0% by weight
Next, a liquid crystal layer forming coating solution is applied by a gravure plate over the entire back surface of the substrate so as to cover the concealing layer, thereby forming a liquid crystal layer having an average thickness of 3 μm after coating. Other than this, that is, the step of forming the background layer and the step of forming the adhesive layer were the same as in Example 1 to prepare a liquid crystal label.
The liquid crystal label obtained as a result exhibited the same effects as in Example 1.
FIG. 5 is a cross-sectional schematic 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 similar to the liquid crystal labels 10 and 110 described above, and includes a base material 212 having transparency or translucency, a liquid crystal layer 214 formed on the back side of the base material 212, and a liquid crystal layer. 214 includes a background layer 216 formed on the surface opposite to the base material 212 and an adhesive layer 218 formed on the back surface of the background layer 216 opposite to the liquid crystal layer 214 side. A separator 220 is temporarily attached to the surface.
Therefore, the liquid crystal label 210 has the same effect as the effects of the liquid crystal labels 10 and 110 described above.
Further, in the liquid crystal label 210, the liquid crystal layer 214 is formed on the back surface side of the base material 212, for example, in a portion excluding the ring-shaped portion.
Further, in the liquid crystal label 210, the background layer 216 is formed on the back surface side of the base material 212 so as to cover the liquid crystal layer 214. The background layer 216 includes a main portion 216a and image line portions 216b and 216c.
The image line portion 216b of the background layer 216 is linearly formed on the surface of the liquid crystal layer 214 opposite to the substrate 212. In addition, the image line portion 216 c of the background layer 216 is formed linearly across the surface of the liquid crystal layer 214 opposite to the substrate 212 and the back surface of the substrate 212. Further, the main portion 216a of the background layer 216 is formed on the back surface side of the base material 212 so as to cover the liquid crystal layer 214 and the image line portions 216b and 216c.
The background layer 216 is formed so that the infrared absorption rate of the image portions 216b and 216c is larger than the infrared absorption rate of the main portion 216a.
Further, the background layer 216 has a small color difference E ^* ab in the visible range between the main portion 216a and the image line portions 216b and 216c, and it is difficult to distinguish the main portion 216a from the image line portions 216b and 216c under visible light. The image portions 216b and 216c are configured not to be identified under visible light.
As a material for the main portion 216a of the background layer 216, for example, non-carbon ink is used. As the non-carbon ink, for example, the following UV curable ink is used.
UV KST SL FL resistant black ink from T & K TOKA Co. Further, as the material of the image portions 216b and 216c of the background layer 216, for example, ink containing carbon black is used. As the carbon black ink, for example, the following UV curable ink is used.
No. of T & K TOKA. 5 BF ink OS
Note that, as described above, in order to configure the image portions 216b and 216c of the background layer 216 so as not to be identified under visible light, in the visible region between the main portion 216a and the image portions 216b and 216c of the background layer 216. it is preferred that the color difference E ^* ab 6 or less, it is more preferable to the color difference E ^* ab in 3 below.
In the liquid crystal label 210 shown in FIG. 5, a plan view of the liquid crystal label 210 when viewed under visible light is seen through the base material 212 as shown in FIG. The background layer 216 looks like a black ring in the portion where the liquid crystal layer 214 does not exist.
Further, in the liquid crystal label 210 shown in FIG. 5, the surface of the liquid crystal label 210 is irradiated with infrared rays in the dark, and the reflected light from the surface side of the liquid crystal label 210 is converted into a CCD camera (the Sony video camera DCR-PC120 is in the night shot mode). As shown in FIG. 7, the image lines 216b and 216c of the background layer 216 appear dark and the other parts appear bright.
Therefore, the liquid crystal label 210 can further improve the accuracy of label authenticity discrimination as compared with the liquid crystal labels 10 and 110 described above.
In this liquid crystal label 210, the image line portions 216b and 216c of the background layer 216 are formed in three straight lines, but the number of the image line portions of the background layer can be arbitrarily changed to 1, 2 or 4 or more. The shape of the image portion of the background layer may be arbitrarily changed to a character shape, a figure shape, a symbol shape, or the like.
The liquid crystal label 210 is formed so that the infrared absorption rate of the image line portions 216b and 216c is larger than the infrared absorption rate of the main portion 216a of the background layer 216. The line portion 216b and 216c may be formed so that the infrared absorption rate of the main portion 216a is larger than the infrared absorption rate of the line portions 216b and 216c. In this case, in the above-described image of the CCD camera, the main portion 216a of the background layer 216 becomes dark, and the image line portions 216b and 216c of the background layer 216 become bright.
In the liquid crystal label 210, the main portion 216 a of the background layer 216 may not be formed on the surface opposite to the base material 212 in the image line portions 216 b and 216 c. Thus, even if the main portion 216a of the background layer 216 is not formed on the image line portions 216b and 216c, the same effect can be obtained.
In the liquid crystal label 210, the entire main surface portion 216a of the background layer 216 may be formed of carbon black ink or non-carbon ink without forming the image line portions 216b and 216c of the background layer 216. Thus, if the entire main surface portion 216a of the background layer 216 is formed of carbon black ink, the entire image of the CCD camera described above becomes dark, and if the entire main surface portion 216a of the background layer 216 is formed of non-carbon ink, The entire image from the above-described CCD camera becomes brighter.
Further, in the liquid crystal label 210, a part of the background layer 216 may be formed of non-carbon ink, and the remaining part may be formed of carbon ink. For example, if the right half of the background layer 216 of the liquid crystal label 210 is made of non-carbon ink and the left half is made of carbon ink, the right half of the image on the above-mentioned CCD camera becomes bright and the left half becomes dark. .
Further, in the liquid crystal label 210, the color difference E ^* ab in the visible region between the main portion 216a of the background layer 216 and the image portions 216b and 216c may exceed 6. In this way, the image line portions 216b and 216c of the background layer 216 are easily identified under visible light. However, when the infrared light is irradiated and the reflected light is received by a CCD camera or the like, the main portion of the background layer 216 is obtained. Since the difference in infrared absorptance between 216a and the image line portions 216b and 216c can be clearly seen, the accuracy of label authenticity discrimination can be improved as compared with the liquid crystal labels 10 and 110 described above.
The liquid crystal label 210 is also peeled between layers when it is peeled off from the adherend after being attached to the adherend that is a genuine product, like the liquid crystal labels 10 and 110 described above. In order to prevent a part of the layers from being broken and replaced with a fake, the following structure may be adopted.
That is, in each of the liquid crystal labels described above, the adhesive strength between the base material and the liquid crystal layer is weaker than the adhesive strength between the liquid crystal layer and the background layer, weaker than the adhesive strength between the background layer and the adhesive layer, and the liquid crystal layer, the background layer, and It is preferable that the adhesive layer is weaker than the cohesive fracture strength of each layer. If comprised in this way, when a liquid crystal label is peeled, it will peel between a base material and a liquid crystal layer, and it can prevent resticking without the whole peeling well.
Alternatively, in each liquid crystal label described above, the cohesive failure strength of the liquid crystal layer and / or the background layer of the liquid crystal layer, the background layer, and the adhesive layer is the same as that of the other layers of the liquid crystal layer, the background layer, and the adhesive layer. It is preferably configured to be weaker than the cohesive fracture 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. If comprised in this way, when a liquid crystal label is peeled, a liquid crystal layer and / or a background layer will be destroyed and the whole will not peel well, but it can prevent resticking.
Alternatively, in each liquid crystal label described above, 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 adhesive layer It is preferable that at least one of the cohesive failure strength of each of the layers excluding the cohesive failure strength of the liquid crystal layer and the cohesive failure strength of the background layer is configured to be weaker than the cohesive failure strength of the adhesive layer. If comprised in this way, when a liquid crystal label is peeled off, it will peel off between layers and / or a liquid crystal layer and / or a background layer will be destroyed, and the whole will not peel off well, but it will prevent reattachment be able to. In this case, the adhesive strength between each layer, 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 strength of each layer excluding the adhesive layer For example, two or more of the cohesive failure strength of the liquid crystal layer and the cohesive failure strength of the background layer may be formed equally.
Convex characters and blank characters in each of the liquid crystal labels described above can be formed using gravure printing, flexographic printing, letterpress printing, screen printing, etc. It is preferable because it is easy to form clearly, and more preferably, it is formed by gravure printing.
Further, the image portions 216b and 216c of the background layer 216 in the liquid crystal label 210 shown in FIG. 5 can also be formed by using gravure printing, flexographic printing, letterpress printing, screen printing, etc. Printing and flexographic printing are preferable because they can easily form a clear line, and more preferably, gravure printing.
Further, the entire surface coating (solid) may be formed by any of the above-described printing methods, and can also be performed by a method such as a knife coater or a bar coater.
In the description of the embodiment, the label continuous body in which a plurality of labels are formed on the separator has been described. However, the separator is not temporarily attached to the surface of the adhesive layer made of an adhesive, and the liquid crystal layer side of the substrate is On the opposite surface, a material with excellent releasability such as silicone is applied to form a release layer, the adhesive layer is the inside, and the surface on which the release layer of the base material is formed is the outside. It is good also as a label continuous body which can be returned and used.

  According to the present invention, a liquid crystal label and a liquid crystal label that are flexible, easy to stick along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. A continuum and a method for producing the same can be provided.

[0002]
It is not suitable for use as a label and is not very flexible. That is, on a layer such as a liquid crystal layer, a microsphere transparent bead having a diameter of 10 to 100 μm, preferably 50 μm or less, preferably a glass (hard) bead, while the layer still does not lose its adhesiveness. It is difficult to control because it must be formed in a single layer so that it does not overlap evenly, preferably two or more layers, so there is a problem in the reproducibility of manufacturing, and the yield must be reduced. Costs are rising and flexibility is insufficient.
Therefore, those that do not employ the operation of aligning the microbeads or the operation of laminating other layers with the liquid crystal layer having a sticky state can produce a label with the same performance with high reproducibility, good yield, and relatively It is easy to manufacture an anti-counterfeit label that can be manufactured at a low cost and that can be immediately distinguished from a general-purpose label only by changing the viewing direction and observing the label.
Therefore, the main object of the present invention is to provide a liquid crystal that is flexible, easy to stick along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. It is to provide a label, a liquid crystal label continuous body, and a production method thereof.
DISCLOSURE OF THE INVENTION A liquid crystal label according to claim 1 according to the present invention includes a transparent or translucent substrate, a liquid crystal layer formed on the back side of the substrate and containing a liquid crystal composition comprising a cholesteric phase. The liquid crystal label includes a background layer formed on the entire surface of the liquid crystal layer opposite to the substrate and an adhesive layer formed on the surface of the background layer opposite to the liquid crystal layer.
The liquid crystal label according to claim 3 according to the present invention is the liquid crystal label according to claim 1, wherein the liquid crystal layer is partially formed on the back surface of the substrate.
According to a fourth aspect of the present invention, in the liquid crystal label, the back surface of the substrate is partially

[0003]
The liquid crystal label according to claim 1, wherein a concealing layer is formed and a liquid crystal layer is formed on the back surface of the substrate so as to cover the concealing layer.
The liquid crystal label according to claim 5 according to the present invention is the liquid crystal label according to claim 1, claim 3, or claim 4, wherein the background layer has a portion having a difference in infrared absorption rate.
The liquid crystal label according to claim 6 according to the present invention is the liquid crystal label according to claim 5, wherein a portion provided with a difference in infrared absorption rate in the background layer is configured not to be identified under visible light. is there.
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. The liquid crystal label according to claim 1, claim 3, claim 4, claim 5, or claim 6.
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 weaker than the adhesive strength between the liquid crystal layer and the background layer, and is weaker than the adhesive strength between the background layer and the adhesive 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 of the layer, the background layer, and the adhesive layer.
According to a ninth aspect of the present invention, in the liquid crystal label, the cohesive failure strength of the liquid crystal layer and / or the background layer of the liquid crystal layer, the background layer and the adhesive layer is It was weaker than the cohesive fracture strength of 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 The liquid crystal label according to claim 7.
According to a tenth aspect of the present invention, there is provided the liquid crystal label according to the present invention, wherein 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, the cohesive failure strength of the liquid crystal layer, and Cohesive fracture strength of the background layer

[0004]
The liquid crystal label according to claim 7, wherein the strength of at least one of the degrees is configured to be weaker than the cohesive failure strength of the adhesive layer.
The liquid crystal label continuous body according to claim 11 according to the present invention has a transparent or translucent surface, a surface provided with a peelable surface, and a cholesteric phase formed on the back side of the substrate. A liquid crystal layer containing a liquid crystal composition, a background layer formed on the entire surface of the liquid crystal layer opposite to the substrate, and an adhesive layer formed on the surface of the background layer opposite to the liquid crystal layer It is a liquid crystal label continuous body that is wound with the surface of the substrate as the outside and the adhesive layer as the inside.
The liquid crystal label continuous body according to claim 12 of the present invention is a liquid crystal containing a base material having a transparent or semi-transparent label, and a liquid crystal composition comprising a cholesteric phase formed on the back side of the base material. A layer, a background layer formed on the entire surface of the liquid crystal layer opposite to the substrate, and an adhesive layer formed on the surface of the background layer opposite to the liquid crystal layer. It is the liquid crystal label continuous body temporarily attached to the separator on the surface of the layer opposite to the background layer.
According to a thirteenth aspect of the present invention, there is provided a liquid crystal label manufacturing method comprising: forming a liquid crystal layer containing a liquid crystal composition composed of a cholesteric phase on the back side of a transparent or translucent substrate; A method for producing a liquid crystal label, comprising: forming a background layer on the entire surface of the layer opposite to the base material; and forming an adhesive layer on the surface of the background layer opposite to the liquid crystal layer. .
In the method for producing a liquid crystal label according to claim 14, according to the present invention, the step of forming the liquid crystal layer comprises applying a liquid crystal layer forming coating solution and heating the coated material to a temperature at which a cholesteric phase can be formed. Forming a cholesteric phase and immobilizing the cholesteric phase by UV crosslinking by ultraviolet irradiation.

（表１の注）表１の相転移温度の欄において、Ｃは結晶性固体、Ｓはスメクチック相、Ｓｃ^*はキラルスメクチックＣ相、Ｃｈはコレステリック相、Ｎ^*はキラルネマチック相、Ｉは等方性液体を表す。
【００１３】
また、表２に示す単独でネマチック相を示す化合物に、表３に示すキラル化合物を加えてもキラルネマチック相を形成する（以下、コレステリック相、キラルネマチック相の区別をせずに、コレステリック相と総称する）。
【００１４】
【表２】

（表２の注）表２の相転移温度の欄において、Ｃは結晶性固体、Ｎはネマチック相、Ｉは等方性液体を表す。
【００１５】
【表３】

（表３の注）ネマチック相を示す液晶にキラル分子を添加すると、キラルネマチック相（Ｎ^*）が得られる。この場合、その混合液晶のピッチの逆数１／ｐは、キラル分子のモル濃度ｘ_B が小さい領域では、ｘ_B に比例する。それゆえ、１／ｐｘ_B のことを、キラルのねじり力という。
【００１６】
この発明にかかる液晶層１４は、コレステリック相が固定されたものであり、その固定の方法としては、たとえば、液晶分子の両末端にアクリル基を有さしめ、これを基材１２に塗工し、この塗工物をコレステリック相を形成し得る温度まで加熱し、コレステリック相を形成し、紫外線照射をすることにより、ＵＶ架橋してコレステリック相を固定する。
そのため、温度等、環境が変化しても、コレステリック相は安定して存在する。
あるいは、液晶分子と一般的に用いられるバインダーの混合物を塗工し、コレステリック相を形成し得る温度に加熱し、コレステリック相を形成し、乾燥し、バインダーでコレステリック相を固定してもよい。
【００１７】
液晶層形成用塗液は、溶剤系でも非溶剤系でもよい。
溶剤系では、溶剤としてＭＥＫ，ＭＩＢＫ等のケトン類、トルエン、酢酸エチル等が好ましい。また、固形分濃度は、特に制限はないが、２５〜６７％が好ましい。２５％を下回ると、画線を鮮明に形成できなくなるおそれがあり、乾燥に要する時間が長くなる。６７％を超えると塗液を加熱しないと固体が析出するおそれがある。特に好ましい濃度範囲は、５０〜６５％である。塗液からの溶剤の蒸発等による固体の析出のおそれをなくすために、塗液を加熱しながら塗工することも行われる。
非溶剤系では、塗工組成物をコレステリック相を形成する最低温度以上、好ましくはコレステリック相を形成する温度領域の温度に加熱しながら塗工を行う。
溶剤系でも、非溶剤系でも、コレステリック相の固定を行うため、コレステリック相を形成する温度範囲に液晶層形成用塗工物を保ったまま、架橋等を行う。これによって、コレステリック相は、温度環境等が変わっても、たとえば常温においても安定的に維持される。
【００１８】
コレステリック相からなる液晶層１４は、光輝性を示し、見る方向によって連続的に色調が変化する。たとえば、上から垂直に見たときにはグリーンに見え、水平に近い方向に見たときにはブルーに見えるといった如くである。
このコレステリック相を示す液晶層１４は、広いスペクトル領域で入射する光の一部の波長領域のみが反射し、これ以外の領域の波長は、すべて透過するという特徴を有する。
【００１９】
この液晶層１４は、基材１２の裏面に全面にわたって形成されるのではなく、文字、絵等からなる画線が、液晶層１４を形成する液晶層形成用塗液を塗工して凸文字や抜き文字が形成されることによって、画線を構成するように形成されている。
なお、螺旋のピッチＰ（図２図示）が大きくなると、長波長側の色が現われ、螺旋のピッチＰが小さくなると、短波長側の色が現われる。このピッチを変えるには、キラル化合物を添加した系においては、キラル化合物の添加量を変更すればよい。
【００２０】
背景層１６は、墨インキや赤、青等の着色インキ等を印刷・塗工することによって形成される。背景層１６は、液晶層１４の光輝性を際立たせるために形成されたもので、液晶層１４を覆うように基材１２の裏面全面にわたって形成されている。特に、背景層１６としては、墨インキ等で形成された黒色が、液晶層１４の光輝性を際立たせるために優れている。
また、背景層１６の色彩によって、液晶層１４の目視での色調が変化するので、背景層１６を形成するインキの組成や色が重要である。たとえば、背景層１６の色が黒のときは、液晶層１４を目視すると、グリーンからブルーの光輝性を示すのに対し、背景層１６が赤のときは、液晶層１４を目視すると、オレンジから紫の光輝性を示し、また、背景層１６が白に近い着色のときには、液晶層１４は、乳白色またはパール調を示す。
したがって、背景層１６を形成する色を２以上に区分けして形成すると、液晶層１４を目視したとき、背景層１６の色彩の変化に対応した彩り鮮やかな液晶ラベルとなる。
【００２１】
接着剤層１８は、アクリル系、ゴム系等の一般的な粘着剤が塗布されて形成されている。
接着剤層１８の表面には、紙等の表面にシリコーン等の剥離剤が塗工されてなるセパレータ２０が仮着されている。
【００２２】
被貼着体に貼付けられた液晶ラベル１０を被貼着体から剥がそうとしたとき、液晶ラベル１０が破壊して偽物のラベルに貼り替えられないようにするために、たとえば、次のような構成としてもよい。
基材１２と液晶層１４の接着強度を、他の層間の接着強度、すなわち図１の場合は液晶層１４と背景層１６間および背景層１６と接着剤層１８間の接着強度、および各層の凝集破壊強度より弱く構成する。その方法としては、たとえば、液晶層形成用塗液にバインダーを全く用いずまたはバインダーの量を抑制して、基材１２と液晶層１４との接着強度を調整する方法がある。
また、背景層１６および／または液晶層１４の凝集破壊強度を、他の層の凝集破壊強度および各層間の接着強度より弱く構成してもよい。
このようにすれば、基材１２と液晶層１４との間で層間剥離をしたり、背景層１６および／または液晶層１４において、凝集破壊し、液晶ラベル１０を被貼着体から剥がそうとしたとき、液晶ラベル１０が破壊して、他の偽物の品物にラベルを貼り替え、偽物を真正品と見せかけることができなくなる。
【００２３】
【実施例１】
基材として、特に表面処理が施されていない、幅１６０ｍｍ、厚さ５０μｍのＰＥＴフィルム（株式会社東洋紡製Ｅ−５０００）を準備し、別途、基材の裏面に塗工されて液晶層を構成する塗液を準備する。
液晶層形成用塗液としては、次の混合塗液を用いる。
両末端にアクリル基を有するネマチック液晶（ＢＡＳＦ社のPaliocolor LC242）・・・５５．３重量％
キラル化合物（ＢＡＳＦ社のPaliocolor LC756）・・・２．９重量％
紫外線重合開始剤（チバスペシャリティ−ケミカルズ社のIrgacure 369）・・・１．８重量％
溶媒としてのメチルエチルケトン（ＭＥＫ）・・・４０．０重量％
この液晶形成用塗液をもって、グラビア版により、乾燥後の厚さが３μｍとなるように、絵柄を含めて、凸文字、抜き文字の画線を形成するように塗工して、乾燥ゾーン（１１０〜１２０℃）を１５秒間通過させて乾燥させ、コレステリック相を形成する。その後直ちに、紫外線照射をして、紫外線ＵＶ硬化を行い、コレステリック相を固定する。ネマチック液晶を形成する温度は、５９℃以上１２０〜１２４℃以下である。
これによって、基材上に、安定的なコレステリック相からなる液晶層を形成する（液晶層を形成するステップ）。
次に、背景層を形成するための墨インキ塗液（東洋インキ製造株式会社製ＰＡＮＮ ＥＣＯ）を準備し、この墨インキ塗液を基材の裏面に、液晶層を覆うように、グラビア版により乾燥後の平均厚さ３μｍとなるよう塗工する。その後、乾燥ゾーン（７０〜８０℃）を３秒間通過させて、墨インキ塗液を乾燥する。
而して、液晶層を覆う背景層が基材の裏面に形成される（背景層を形成するステップ）。
【００２４】
次に、紙の表面にシリコーン等の剥離剤が塗工されたセパレータの表面に、粘着剤が塗工されたものを別途準備し、前記基材の裏面に形成された背景層側の裏面とセパレータの表面に形成された接着剤層の表面とを対向させ、両者を積層ローラ間を通過させることにより積層する（接着剤層を形成するステップ）。
【００２５】
さらに、前記基材、液晶層および背景層からなる積層体と接着剤層およびセパレータの積層体とを積層した積層体を適宜な大きさのラベル（２０×７０ｍｍ）に成形するために、基材の表面側よりセパレータの接着剤層側表面に至るようにダイカットを施す。このように、所定のラベル形状を成形した後、ラベル以外の不要なカス部分をセパレータ表面より取り除くカス上げを行う。
なお、このラベルは、図３に示すように、セパレータの幅方向に一定の間隔（６ｍｍ間隔）をおいて、６列形成され、各列のラベルは、セパレータの長手方向に一定の間隔（３ｍｍ間隔）をおいて配列して設けられている。そこで、幅方向において６列に並列されたラベル間において、等間隔にセパレータをスリットし、セパレータを６本に分断して、それぞれのセパレータの表面にラベルが所定の間隔をおいて、連続して配列されたラベル連続体を作成した。
なお、このラベルの形状やラベル間の間隔は、適宜変更してもよい。
【００２６】
この実施例の液晶ラベルは、基材側から見ると、見る方向によって、緑ないし青紫に変化する鮮やかな光輝性を示した。
また、この実施例においては、液晶層を構成する液晶層形成用塗液に、バインダーを全く用いずに液晶層を形成しているので、基材と液晶層の界面の接着強度が、他の層間の接着強度や各層の凝集破壊強度より弱くなっているために、被貼着体（ポリプロピレンからなる）に貼り付けし、被貼着体に貼り付けられた液晶ラベルを破壊することなく剥がそうと試みたが、基材と液晶層との間で剥離し、ラベルを被貼着体から破壊することなく剥がすことはできなかった。
なお、この実施例においては、液晶層形成用塗液にバインダーを用いなかったが、バインダーの量を少量加えても、その量を抑制することによって、前記したように、基材と液晶層の界面の接着強度を他の層間の界面の接着強度や各層の凝集破壊強度より弱く設計することができる。
【００２７】
図４は、この発明の別の実施の形態である液晶ラベルの断面図解図である。
図４に示す液晶ラベル２１０は、上述の液晶ラベル１０と同様に、透明または半透明性を有する基材２１２と、基材２１２の裏面側に形成された液晶層２１４と、液晶層２１４の基材２１２とは反対側の面に形成された背景層２１６と、背景層２１６の液晶層２１４側とは反対側の裏面に形成された接着剤層２１８とからなり、接着剤層２１８の表面にはセパレータ２２０が仮着されている。
そのため、この液晶ラベル２１０は、上述の液晶ラベル１０が奏する効果と同様の効果を奏する。
【００２８】
また、この液晶ラベル２１０では、液晶層２１４は、基材２１２の裏面側において、たとえばリング状の部分を除いた部分に形成される。
さらに、この液晶ラベル２１０では、背景層２１６は、基材２１２の裏面側に液晶層２１４を覆うようにして形成される。この背景層２１６は、主部分２１６ａと画線部分２１６ｂおよび２１６ｃとからなる。
背景層２１６の画線部分２１６ｂは、液晶層２１４において基材２１２とは反対側の面に直線状に形成される。また、背景層２１６の画線部分２１６ｃは、液晶層２１４において基材２１２とは反対側の面と基材２１２の裏面とにわたって直線状に形成される。さらに、背景層２１６の主部分２１６ａは、基材２１２の裏面側において、液晶層２１４と画線部分２１６ｂおよび２１６ｃとを覆うようにして形成される。
また、背景層２１６は、主部分２１６ａの赤外線の吸収率に対して画線部分２１６ｂおよび２１６ｃの赤外線の吸収率が大きくなるように形成される。
さらに、この背景層２１６は、主部分２１６ａと画線部分２１６ｂおよび２１６ｃとの可視域での色差Ｅ^*ａｂが小さく、可視光下で主部分２１６ａと画線部分２１６ｂおよび２１６ｃとが区別しにくく、画線部分２１６ｂおよび２１６ｃが可視光下で識別されないように構成される。
【００２９】
この背景層２１６の主部分２１６ａの材料としては、たとえばノンカーボンインキが使用される。ノンカーボンインキとしては、たとえばＵＶ硬化型の次のインキが使用される。
Ｔ＆Ｋ ＴＯＫＡ社のＵＶ ＫＳＴ ＳＬ ＦＬ 耐性墨
また、この背景層２１６の画線部分２１６ｂおよび２１６ｃの材料としては、たとえばカーボンブラック入りインキが使用される。カーボンブラックインキとしては、たとえばＵＶ硬化型の次のインキが使用される。
Ｔ＆Ｋ ＴＯＫＡ社のＮｏ．５ ＢＦ 墨 ＯＳ
【００３０】
なお、上述のように背景層２１６の画線部分２１６ｂおよび２１６ｃを可視光下で識別されないように構成するためには、背景層２１６の主部分２１６ａと画線部分２１６ｂおよび２１６ｃとの可視域での色差Ｅ^*ａｂを６以下にすることが好ましく、その色差Ｅ^*ａｂを３以下にすることがさらに好ましい。
【００３１】
図４に示す液晶ラベル２１０では、それを可視光下で見たときの平面図解図を図５に示すように、基材２１２を透して、光輝性を有する液晶層２１４が見えるとともに、液晶層２１４の存在しない部分において背景層２１６が黒いリング状に見える。
また、図４に示す液晶ラベル２１０では、暗闇の中でその表面に赤外線を照射してその液晶ラベル２１０の表面側からの反射光をＣＣＤカメラ（ソニー社のビデオカメラＤＣＲ−ＰＣ１２０をナイトショットモードで使用）で捉えた映像を図６に示すように、背景層２１６の画線部分２１６ｂおよび２１６ｃが暗く見え、その他の部分が明るく見える。
したがって、この液晶ラベル２１０では、上述の液晶ラベル１０と比べて、ラベル真正性の判別の確度をさらに向上することができる。
【００３２】
なお、この液晶ラベル２１０では、背景層２１６の画線部分２１６ｂおよび２１６ｃが３本の直線状に形成されているが、背景層の画線部分の数は１、２または４以上に任意に変更されてもよく、また、背景層の画線部分の形状は文字状、図形状、記号状などに任意に変更されてもよい。
【００３３】
また、この液晶ラベル２１０では、背景層２１６の主部分２１６ａの赤外線の吸収率に対して画線部分２１６ｂおよび２１６ｃの赤外線の吸収率が大きくなるように形成されているが、背景層２１６の画線部分２１６ｂおよび２１６ｃの赤外線の吸収率に対して主部分２１６ａの赤外線の吸収率が大きくなるように形成されてもよい。この場合、上述のＣＣＤカメラの映像において、背景層２１６の主部分２１６ａが暗くなり、背景層２１６の画線部分２１６ｂおよび２１６ｃが明るくなる。
【００３４】
なお、この液晶ラベル２１０において、背景層２１６の主部分２１６ａは、画線部分２１６ｂおよび２１６ｃにおいて基材２１２とは反対側の面上には形成されなくてもよい。このように画線部分２１６ｂおよび２１６ｃ上に背景層２１６の主部分２１６ａが形成されなくても、同様の効果を奏する。
【００３５】
また、この液晶ラベル２１０において、背景層２１６の画線部分２１６ｂおよび２１６ｃを形成せずに、背景層２１６の全体がカーボンブラックインキまたはノンカーボンインキで形成されてもよい。このように背景層２１６の全体をカーボンブラックインキで形成すれば、上述のＣＣＤカメラでの映像の全体が暗くなり、背景層２１６の全体をノンカーボンインキで形成すれば、上述のＣＣＤカメラでの映像の全体が明るくなる。
【００３６】
また、液晶ラベル２１０において、背景層２１６の一部分がノンカーボンインキで形成され、残りの部分がカーボンインキで形成されてもよい。たとえば、液晶ラベル２１０の背景層２１６の右半分がノンカーボンインキで形成され、左半分がカーボンインキで形成されると、上述のＣＣＤカメラでの映像は右半分が明るくなり、左半分が暗くなる。
【００３７】
さらに、この液晶ラベル２１０において、背景層２１６の主部分２１６ａと画線部分２１６ｂおよび２１６ｃとの可視域での色差Ｅ^*ａｂが６を超えるようにしてもよい。このようにすると、背景層２１６の画線部分２１６ｂおよび２１６ｃが可視光下で識別されやすくなってしまうが、赤外線を照射してその反射光をＣＣＤカメラなどで受光すると、背景層２１６の主部分２１６ａと画線部分２１６ｂおよび２１６ｃとの赤外線の吸収率の違いが明瞭に分かるので、上述の液晶ラベル１０と比べて、ラベル真正性の判別の確度を向上することができる。
【００３８】
なお、この液晶ラベル２１０も、上述の液晶ラベル１０と同様に、真正品である被貼着体に貼付けられた後に、その被貼着体から剥離された場合に、層間で剥離しまたは一部の層が破壊して偽物に張り替えられないようにするために、次のように構成されてもよい。
すなわち、上述の各液晶ラベルにおいて、基材および液晶層間の接着強度は、液晶層および背景層間の接着強度より弱く、背景層および接着剤層間の接着強度より弱く、かつ、液晶層、背景層および接着剤層の各層の凝集破壊強度より弱く構成されることが好ましい。このように構成すれば、液晶ラベルを剥離した場合に、基材および液晶層間で剥離して、全体がうまく剥離せずに、再貼着を防止することができる。
あるいは、上述の各液晶ラベルにおいて、液晶層、背景層および接着剤層のうちの液晶層および／または背景層の凝集破壊強度は、液晶層、背景層および接着剤層のうちの他の層の凝集破壊強度より弱く、基材および液晶層間の接着強度より弱く、液晶層および背景層間の接着強度より弱く、かつ、背景層および接着剤層間の接着強度より弱く構成されることが好ましい。このように構成すれば、液晶ラベルを剥離した場合に、液晶層および／または背景層が破壊して、全体がうまく剥離せずに、再貼着を防止することができる。
あるいは、上述の各液晶ラベルにおいて、各層間の接着強度、たとえば、基材および液晶層間の接着強度、液晶層および背景層間の接着強度、背景層および接着剤層間の接着強度、および接着剤層を除く各層の凝集破壊強度、たとえば、液晶層の凝集破壊強度、背景層の凝集破壊強度のうちの少なくとも１つの強度が、接着剤層の凝集破壊強度より弱く構成されることが好ましい。このように構成すれば、液晶ラベルを剥離した場合に、層間で剥離し、および／または、液晶層および／または背景層が破壊して、全体がうまく剥離せずに、再貼着を防止することができる。この場合、各層間の接着強度、たとえば、基材および液晶層間の接着強度、液晶層および背景層間の接着強度、背景層および接着剤層間の接着強度、および接着剤層を除く各層の凝集破壊強度、たとえば、液晶層の凝集破壊強度、背景層の凝集破壊強度のうちの２以上の強度が、同等に形成されてもよい。
【００３９】
なお、上述の各液晶ラベルにおける凸文字、抜き文字は、グラビア印刷、フレキソ印刷、凸版印刷、スクリーン印刷等を用いて形成することができるが、その中でも、グラビア印刷、フレキソ印刷が、画線をクリアに形成し易い等のため好ましく、より好ましくは、グラビア印刷によって形成することである。
【００４０】
また、図４に示す液晶ラベル２１０における背景層２１６の画線部分２１６ｂおよび２１６ｃについても、グラビア印刷、フレキソ印刷、凸版印刷、スクリーン印刷等を用いて形成することができるが、その中でも、グラビア印刷、フレキソ印刷が、画線をクリアに形成し易い等のため好ましく、より好ましくは、グラビア印刷によって形成することである。
また、全面塗工（ベタ）は、前記したいずれの印刷方法によって形成してもよく、さらに、ナイフコーター、バーコータ等の方法によって塗工することもできる。
【００４１】
なお、前記実施の形態の説明において、セパレータ上に複数のラベルを形成したラベル連続体について説明したが、セパレータを粘着剤からなる接着剤層表面に仮着せず、基材の液晶層側とは反対側の表面に、シリコーン等の剥離性に優れた材料を塗布して剥離層を形成し、接着剤層を内側とし、基材の剥離層を形成した表面を外側として巻回し、使用時に巻き戻して使用することができるラベル連続体としてもよい。
【００４２】
また、背景層は、隠蔽効果が出る厚み以上であればよく、たとえば、１μｍ以上が好ましく、さらには、２〜５μｍ程度が、より好ましい。
【産業上の利用可能性】
【００４３】
この発明によれば、しなやかで、被貼着体の面に沿って貼着し易く、比較的低コストで製造することができ、偽造防止用ラベルとして用いることが可能な、液晶ラベル、液晶ラベル連続体およびその製造方法を提供することができる。
【図面の簡単な説明】
【００４４】
【図１】この発明の一実施の形態である液晶ラベルの断面図解図である。
【図２】コレステリック相の分子配列を示す図解図である。
【図３】ラベル連続体の製造方法を示す平面図解図である。
【図４】この発明の別の実施の形態である液晶ラベルの断面図解図である。
【図５】図４に示す液晶ラベルを可視光下で見たときの平面図解図である。
【図６】暗闇の中で図４に示す液晶ラベルの表面に赤外線を照射してその液晶ラベルの表面側からの反射光をＣＣＤカメラで捉えた映像を示す図解図である。
【符号の説明】
【００４５】
１０、２１０ 液晶ラベル
１２、２１２ 基材
１４、２１４ 液晶層
１６、２１６ 背景層
１８、２１８ 接着剤層
２０、２２０ セパレータ [Document Name] Description [Technical Field]
[0001]
The present invention relates to a liquid crystal label, a liquid crystal label continuous body, and a liquid crystal label continuous body, and more particularly, to a liquid crystal label suitable for use as a label capable of preventing forgery, a liquid crystal label continuous body, and a method for manufacturing the same.
[Background]
[0002]
Conventionally, the recording layer of the label has been formed by thermal recording, thermal color development, printing, etc., so it is relatively easy to make a fake label. I have. In addition, a label using a material that emits light when irradiated with ultraviolet rays, infrared rays, or the like can be recognized as a fake only by irradiating ultraviolet rays or infrared rays, and it is difficult to determine authenticity only by visual observation.
In view of this, there has been proposed a label capable of authenticity identification, such as an authenticity identification label disclosed in JP-A-2002-205471.
[0003]
[Patent Document 1] Japanese Patent Laid-Open No. 2002-205471
DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
[0004]
This conventional authenticity distinguishable label uses a display material containing a cholesteric liquid crystal pigment, which is rarely used as a display material of the conventional label. Therefore, if there is no knowledge of these materials, the function of the material is exhibited. For this reason, it is suitable as an anti-counterfeit label because it is difficult to forge.
However, since it is difficult to realize the object of the invention, the cost of the label increases, and for example, it is not suitable for use as an anti-counterfeit label for a low-priced part, and is not flexible. That is, on a layer such as a liquid crystal layer, a microsphere transparent bead having a diameter of 10 to 100 μm, preferably 50 μm or less, preferably a glass (hard) bead, while the layer still does not lose its adhesiveness. It is difficult to control because it must be formed in a single layer so that it does not overlap evenly, preferably two or more layers, so there is a problem in the reproducibility of manufacturing, and the yield must be reduced. Costs are rising and flexibility is insufficient.
Therefore, those that do not employ the operation of aligning the microbeads or the operation of laminating other layers with the liquid crystal layer having a sticky state can produce a label with the same performance with high reproducibility, good yield, and relatively It can be manufactured at low cost and is easy to manufacture.
[0005]
Therefore, the main object of the present invention is to provide a liquid crystal that is flexible, easy to stick along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. It is to provide a label, a liquid crystal label continuous body, and a production method thereof.
[Means for Solving the Problems]
[0006]
The liquid crystal label according to claim 1 of the present invention includes a base material having transparency or translucency, and a liquid crystal layer that is partially formed on the back side of the base material and contains a liquid crystal composition composed of a cholesteric phase. A background layer having a concealing property formed so as to cover the liquid crystal layer over the entire back surface side of the substrate, and an adhesive layer formed on the back surface side of the substrate having the liquid crystal layer and the background layer, A liquid crystal label in which an image line is expressed by the color tone of the background layer seen through visible light and the color tone of the liquid crystal layer highlighted by the background layer.
This liquid crystal label can be used as an anti-counterfeit label that can immediately identify the difference from a general-purpose label simply by changing the viewing direction and observing the label.
According to a second aspect of the present invention, in the liquid crystal label according to the first aspect, the background layer has a portion having a difference in the infrared absorption rate, and the portion is configured so as not to be identified under visible light. It is a liquid-crystal label as described in.
The liquid crystal label according to claim 3 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. The liquid crystal label according to claim 1 or claim 2.
According to a fourth aspect of the present invention, in the liquid crystal label, the adhesive strength between the substrate and the liquid crystal layer is weaker than the adhesive strength between the liquid crystal layer and the background layer, and is weaker than the adhesive strength between the background layer and the adhesive layer. The liquid crystal label according to claim 3, wherein the liquid crystal label is configured to be weaker than the cohesive failure strength of each of the layer, the background layer, and the adhesive layer.
According to a fifth aspect of the present invention, in the liquid crystal label, the cohesive failure strength of the liquid crystal layer and / or the background layer of the liquid crystal layer, the background layer and the adhesive layer is the same among the liquid crystal layer, the background layer and the adhesive layer. Less than the cohesive fracture 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 3.
The liquid crystal label according to claim 6 according to the present invention includes an adhesive strength between the base material 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, a cohesive failure strength of the liquid crystal layer, and The liquid crystal label according to claim 3, wherein at least one of the cohesive failure strengths of the background layer is configured to be weaker than the cohesive failure strength of the adhesive layer.
According to a seventh aspect of the present invention, there is provided a liquid crystal label continuous body having transparency or translucency, a base material having a peelable surface, and a partially formed cholesteric surface on the back side of the base material. A liquid crystal layer containing a liquid crystal composition comprising a phase; a concealing background layer formed to cover the liquid crystal layer over the entire back surface side of the substrate; and a back surface side of the substrate having the liquid crystal layer and the background layer And the adhesive layer formed, and an image line is represented by the color tone of the background layer visible under visible light through the base material and the glittering color tone of the liquid crystal layer highlighted by the background layer. It is a liquid crystal label continuous body wound with the surface of the outer side being the outer side and the adhesive layer being the inner side.
The continuous liquid crystal label according to claim 8 of the present invention is a liquid crystal composition comprising a base material having a transparent or translucent label and a cholesteric phase formed partially on the back side of the base material. A liquid crystal layer containing, a concealing background layer formed so as to cover the liquid crystal layer over the entire back surface side of the substrate, and an adhesive layer formed on the back surface side of the substrate having the liquid crystal layer and the background layer; A line is represented by the color tone of the background layer that is visible under visible light through the substrate and the glittering color tone of the liquid crystal layer that is highlighted by the background layer, and the label is the background layer of the adhesive layer It is the liquid crystal label continuous body temporarily attached to the separator in the surface on the opposite side.
According to a ninth aspect of the present invention, there is provided a method for producing a liquid crystal label continuum according to the eighth aspect, wherein the liquid crystal label continuum is produced on the back side of a transparent or translucent substrate. Applying a coating liquid for forming a liquid crystal layer, heating the coating to a temperature at which a cholesteric phase can be formed to form a cholesteric phase, and UV-crosslinking by UV irradiation to fix the cholesteric phase. The step of forming a liquid crystal layer containing a liquid crystal composition comprising a cholesteric phase and the coating of the background layer forming coating solution so as to cover the liquid crystal layer over the entire back surface side of the base material, A substrate having a liquid crystal layer and a background layer, the step of forming a background layer having the liquid crystal layer and the background layer facing each other, and the back surface side of the substrate having the liquid crystal layer and the background layer facing each other Forming an adhesive layer so that the adhesive layer is formed on the back side of the substrate having the liquid crystal layer and the background layer in a state where the adhesive layer is temporarily attached to the separator. It is a manufacturing method of a body.
【The invention's effect】
[0007]
According to the present invention, a liquid crystal label and a liquid crystal label that are flexible, easy to stick along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. A continuum and a method for producing the same can be provided.
[0008]
The above object, other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the embodiments of the present invention with reference to the drawings.
BEST MODE FOR CARRYING OUT THE INVENTION
[0009]
FIG. 1 is an illustrative sectional view of a liquid crystal label according to an embodiment of the present invention.
The liquid crystal label 10 is a liquid crystal in which a base 12 made of a synthetic resin sheet or film such as a transparent or translucent polyester film or the like, and a cholesteric liquid crystal formed on the back side of the base 12 are fixed. A layer 14, a background layer 16 formed on the surface of the liquid crystal layer 14 opposite to the substrate 12, and formed to highlight the glitter of the liquid crystal layer 14, and the liquid crystal layer of the background layer 16 It consists of an adhesive layer 18 formed by applying an adhesive or the like formed on the surface opposite to the 14 side.
[0010]
As the base material 12, it is suitable to use a plastic film such as transparent PET, a sheet or the like. In particular, the surface of the base material 12 on the side on which the liquid crystal layer 14 is formed (that is, the surface of the base material 12) is transparent. In addition, when the liquid crystal label 10 is to be peeled off from the adherend, it is desirable that the liquid crystal layer 14 is excellent in smoothness so that the liquid crystal layer 14 can be easily delaminated. Furthermore, in order to facilitate delamination between the substrate 12 and the liquid crystal layer 14, it is desirable that the surface side on which the liquid crystal layer is formed is not subjected to surface treatment. Sometimes, fine linear marks may be 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 alignment of liquid crystal molecules constituting the liquid crystal layer 14.
[0011]
A cholesteric liquid crystal is selected as the liquid crystal composition constituting the liquid crystal layer 14, and the cholesteric liquid crystal is formed by coating a compound having a helical cholesteric phase or a chiral nematic phase (see FIG. 2).
Examples of compounds exhibiting a cholesteric phase or a chiral nematic phase include those shown in Table 1 in addition to cholesteryl nonanoate, cholesteryl myristate, and the like.
[0012]
[Table 1]

(Note to Table 1) In the column of phase transition temperature in Table 1, C is a crystalline solid, S is a smectic phase, Sc ^* is a chiral smectic C phase, Ch is a cholesteric phase, N ^* is a chiral nematic phase, I is etc. Represents an isotropic liquid.
[0013]
Further, a chiral nematic phase can be formed by adding a chiral compound shown in Table 3 to a compound showing a nematic phase alone shown in Table 2 (hereinafter, without distinguishing between a cholesteric phase and a chiral nematic phase, Generically).
[0014]
[Table 2]

(Note to Table 2) In the column of the phase transition temperature in Table 2, C represents a crystalline solid, N represents a nematic phase, and I represents an isotropic liquid.
[0015]
[Table 3]

(Note to Table 3) When a chiral molecule is added to a liquid crystal showing a nematic phase, a chiral nematic phase (N ^* ) is obtained. In this case, the reciprocal 1 / p of the pitch of the mixed liquid crystal is proportional to x _B in a region where the molar concentration x _B of the chiral molecule is small. Therefore, 1 / px _B is called chiral torsional force.
[0016]
The liquid crystal layer 14 according to the present invention has a cholesteric phase fixed. As a fixing method, for example, an acrylic group is provided at both ends of liquid crystal molecules, and this is applied to the substrate 12. The coated product is heated to a temperature at which a cholesteric phase can be formed, a cholesteric phase is formed, and UV irradiation is performed by UV irradiation to fix the cholesteric phase.
Therefore, the cholesteric phase exists stably even if 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 formed, dried, and the cholesteric phase fixed with a binder.
[0017]
The liquid crystal layer forming coating solution may be solvent-based or non-solvent-based.
In the solvent system, ketones such as MEK and MIBK, toluene, ethyl acetate and the like are preferable as the solvent. The solid content concentration is not particularly limited, but is preferably 25 to 67%. If it is less than 25%, the image line may not be formed clearly, and the time required for drying becomes longer. If it exceeds 67%, solids may be deposited unless the coating liquid is heated. A particularly preferred concentration range is 50 to 65%. In order to eliminate the possibility of solid precipitation due to evaporation of the solvent from the coating liquid, coating is also performed while heating the coating liquid.
In the non-solvent system, coating is performed while heating the coating composition to a temperature above the minimum temperature at which the cholesteric phase is formed, preferably at a temperature in the temperature range where the cholesteric phase is formed.
In order to fix the cholesteric phase in both the solvent system and the non-solvent system, crosslinking or the like is performed while keeping the liquid crystal layer-forming coating material in the temperature range for forming the cholesteric phase. Thus, the cholesteric phase is stably maintained even at a normal temperature, for example, even if the temperature environment changes.
[0018]
The liquid crystal layer 14 composed of a cholesteric phase exhibits glitter, and the color tone changes continuously depending on the viewing direction. For example, it looks green when viewed vertically from above, and appears blue when viewed in a horizontal direction.
The liquid crystal layer 14 exhibiting the cholesteric phase has a characteristic that only a part of the wavelength region of light incident in a wide spectral region is reflected and all the wavelengths in other regions are transmitted.
[0019]
The liquid crystal layer 14 is not formed on the entire back surface of the substrate 12, but an image line composed of characters, pictures, etc. is applied by applying a liquid crystal layer forming coating liquid to form the liquid crystal layer 14. By forming a blank character, the image line is formed.
When the spiral pitch P (shown in FIG. 2) is increased, the color on the long wavelength side appears, and when the spiral pitch P is decreased, the color on the short wavelength side appears. In order to change this pitch, the addition amount of the chiral compound may be changed in the system to which the chiral compound is added.
[0020]
The background layer 16 is formed by printing / coating with black ink or colored ink such as red and blue. The background layer 16 is formed to make the glitter of the liquid crystal layer 14 stand out, 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, black formed with black ink or the like is excellent for making the glitter of the liquid crystal layer 14 stand out.
Further, since the visual color tone of the liquid crystal layer 14 changes depending on the color of the background layer 16, the composition and color of the ink forming the background layer 16 are important. For example, when the color of the background layer 16 is black, when the liquid crystal layer 14 is visually observed, green to blue glitter is exhibited, whereas when the background layer 16 is red, the liquid crystal layer 14 is visually observed from orange. When the background layer 16 is colored near white, the liquid crystal layer 14 is milky white or pearly.
Therefore, when the colors forming the background layer 16 are divided into two or more, when the liquid crystal layer 14 is viewed, a colorful liquid crystal label corresponding to the color change of the background layer 16 is obtained.
[0021]
The adhesive layer 18 is formed by applying a general adhesive such as acrylic or rubber.
On the surface of the adhesive layer 18 is temporarily attached a separator 20 formed by coating a release agent such as silicone on the surface of paper or the like.
[0022]
In order to prevent the liquid crystal label 10 from being broken and replaced with a fake label when the liquid crystal 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 other layers, that is, the adhesive strength between the liquid crystal layer 14 and the background layer 16 and between the background layer 16 and the adhesive layer 18 in the case of FIG. The composition is weaker than the cohesive fracture strength. As the method, for example, there is a method of adjusting the adhesive strength between the substrate 12 and the liquid crystal layer 14 without using any binder in the liquid crystal layer forming coating liquid or suppressing the amount of the binder.
Further, the cohesive failure strength of the background layer 16 and / or the liquid crystal layer 14 may be configured to be weaker than the cohesive failure strength of other layers and the adhesive strength between the layers.
If it does in this way, delamination between the base material 12 and the liquid-crystal layer 14 will be carried out, the cohesive failure will be carried out in the background layer 16 and / or the liquid-crystal layer 14, and it will try to peel off the liquid-crystal label 10 from a to-be-adhered body. In this case, the liquid crystal label 10 is destroyed, and the label is pasted on another counterfeit item, making it impossible to make the counterfeit item appear to be a genuine item.
[0023]
[Example 1]
As a base material, a surface-treated PET film having a width of 160 mm and a thickness of 50 μm (E-5000 manufactured by Toyobo Co., Ltd.) is prepared and separately applied to the back surface of the base material to form a liquid crystal layer. Prepare the coating solution.
As the liquid crystal layer forming coating solution, the following mixed coating solution is used.
Nematic liquid crystal with acrylic groups at both ends (Paliocolor LC242 from BASF) ... 55.3% by weight
Chiral compound (Paliocolor LC756 from BASF) 2.9% by weight
UV polymerization initiator (Irgacure 369 from Ciba Specialty Chemicals) ... 1.8% by weight
Methyl ethyl ketone (MEK) as solvent: 40.0% by weight
With this liquid crystal forming coating liquid, a gravure plate is applied so that the thickness after drying is 3 μm so as to form an image line of convex letters and blank letters including a pattern, and a drying zone ( 110-120 ° C) for 15 seconds to dry and form a cholesteric phase. Immediately thereafter, ultraviolet irradiation is performed to perform ultraviolet UV curing to fix the cholesteric phase. The temperature for forming the nematic liquid crystal is 59 ° C. or higher and 120 to 124 ° C. or lower.
Thereby, a liquid crystal layer composed of a stable cholesteric phase is formed on the substrate (step of forming a liquid crystal layer).
Next, a black ink coating liquid (PANE ECO manufactured by Toyo Ink Manufacturing Co., Ltd.) for forming the background layer is prepared, and this black ink coating liquid is coated on the back surface of the substrate with a gravure plate so as to cover the liquid crystal layer. It coats so that it may become the average thickness of 3 micrometers after drying. Thereafter, the black ink coating liquid is dried by passing through a drying zone (70 to 80 ° C.) for 3 seconds.
Thus, a background layer covering the liquid crystal layer is formed on the back surface of the substrate (step of forming the background layer).
[0024]
Next, the surface of the separator coated with a release agent such as silicone on the surface of the paper, separately prepared by applying a pressure-sensitive adhesive, and the back side of the background layer formed on the back side of the substrate The surface of the adhesive layer formed on the surface of the separator is opposed to each other, and the two are passed between the lamination rollers to be laminated (step of forming the adhesive layer).
[0025]
Furthermore, in order to form a laminate in which a laminate comprising the substrate, the liquid crystal layer and the background layer and a laminate of an adhesive layer and a separator are laminated into an appropriately sized label (20 × 70 mm), The die is cut so as to reach the adhesive layer side surface of the separator from the surface side. In this manner, after forming a predetermined label shape, the residue is removed by removing unnecessary residue other than the label from the separator surface.
As shown in FIG. 3, the labels are formed in six rows with a constant interval (6 mm interval) in the width direction of the separator, and the labels in each column are fixed intervals (3 mm in the longitudinal direction of the separator). Are arranged at intervals. Therefore, between the labels arranged in six rows in the width direction, the separators are slit at equal intervals, the separators are divided into six, and the labels are continuously provided at predetermined intervals on the surface of each separator. An ordered label continuum was created.
In addition, you may change suitably the shape of this label and the space | interval between labels.
[0026]
When viewed from the base material side, the liquid crystal label of this example showed vivid luster that changed from green to blue-violet depending on the viewing direction.
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 substrate and the liquid crystal layer is Because it is weaker than the adhesive strength between layers and the cohesive failure strength of each layer, it can be attached to an adherend (made of polypropylene) and peeled off without destroying the liquid crystal label attached to the adherend However, it was not possible to peel off the label without destroying it from the substrate and breaking the label from the adherend.
In this example, a binder was not used in the liquid crystal layer forming coating solution. However, even when a small amount of the binder was added, the amount of the binder was suppressed, as described above. The adhesive strength of the interface can be designed to be weaker than the adhesive strength of the interface between other layers and the cohesive failure strength of each layer.
[0027]
FIG. 4 is an illustrative sectional view of a liquid crystal label according to another embodiment of the present invention.
A liquid crystal label 210 illustrated in FIG. 4 is similar to the liquid crystal label 10 described above, and includes a base 212 having transparency or translucency, a liquid crystal layer 214 formed on the back side of the base 212, and a base of the liquid crystal layer 214. A background layer 216 formed on the surface opposite to the material 212, and an adhesive layer 218 formed on the back surface of the background layer 216 opposite to the liquid crystal layer 214, and on the surface of the adhesive layer 218 The separator 220 is temporarily attached.
Therefore, the liquid crystal label 210 has the same effect as that of the liquid crystal label 10 described above.
[0028]
Further, in the liquid crystal label 210, the liquid crystal layer 214 is formed on the back surface side of the base material 212, for example, in a portion excluding the ring-shaped portion.
Further, in the liquid crystal label 210, the background layer 216 is formed on the back surface side of the base material 212 so as to cover the liquid crystal layer 214. The background layer 216 includes a main portion 216a and image line portions 216b and 216c.
The image line portion 216b of the background layer 216 is linearly formed on the surface of the liquid crystal layer 214 opposite to the substrate 212. In addition, the image line portion 216 c of the background layer 216 is formed linearly across the surface of the liquid crystal layer 214 opposite to the substrate 212 and the back surface of the substrate 212. Further, the main portion 216a of the background layer 216 is formed on the back surface side of the base material 212 so as to cover the liquid crystal layer 214 and the image line portions 216b and 216c.
The background layer 216 is formed so that the infrared absorption rate of the image portions 216b and 216c is larger than the infrared absorption rate of the main portion 216a.
Further, the background layer 216 has a small color difference E ^* ab in the visible range between the main portion 216a and the image line portions 216b and 216c, and it is difficult to distinguish the main portion 216a and the image line portions 216b and 216c under visible light. The image portions 216b and 216c are configured not to be identified under visible light.
[0029]
As a material for the main portion 216a of the background layer 216, for example, non-carbon ink is used. As the non-carbon ink, for example, the following UV curable ink is used.
UV KST SL FL resistant black ink from T & K TOKA Co. Further, as the material of the image portions 216b and 216c of the background layer 216, for example, ink containing carbon black is used. As the carbon black ink, for example, the following UV curable ink is used.
No. of T & K TOKA. 5 BF ink OS
[0030]
Note that, as described above, in order to configure the image portions 216b and 216c of the background layer 216 so as not to be identified under visible light, in the visible region between the main portion 216a and the image portions 216b and 216c of the background layer 216. it is preferred that the color difference E ^* ab 6 or less, it is more preferable to the color difference E ^* ab in 3 below.
[0031]
In the liquid crystal label 210 shown in FIG. 4, as shown in FIG. 5, a plan view when the liquid crystal label 210 is viewed under visible light, the liquid crystal layer 214 having a glitter property can be seen through the base material 212, and the liquid crystal In the part where the layer 214 does not exist, the background layer 216 appears as a black ring.
Further, in the liquid crystal label 210 shown in FIG. 4, the surface of the liquid crystal label 210 is irradiated with infrared rays in the dark, and the reflected light from the surface side of the liquid crystal label 210 is converted into a CCD camera (Sony video camera DCR-PC120 in the night shot mode). As shown in FIG. 6, the image lines 216b and 216c of the background layer 216 appear dark and the other parts appear bright.
Therefore, the liquid crystal label 210 can further improve the accuracy of label authenticity discrimination as compared with the liquid crystal label 10 described above.
[0032]
In this liquid crystal label 210, the image line portions 216b and 216c of the background layer 216 are formed in three straight lines, but the number of the image line portions of the background layer can be arbitrarily changed to 1, 2 or 4 or more. The shape of the image portion of the background layer may be arbitrarily changed to a character shape, a figure shape, a symbol shape, or the like.
[0033]
The liquid crystal label 210 is formed so that the infrared absorption rate of the image line portions 216b and 216c is larger than the infrared absorption rate of the main portion 216a of the background layer 216. The line portion 216b and 216c may be formed so that the infrared absorption rate of the main portion 216a is larger than the infrared absorption rate of the line portions 216b and 216c. In this case, in the above-described image of the CCD camera, the main portion 216a of the background layer 216 becomes dark, and the image line portions 216b and 216c of the background layer 216 become bright.
[0034]
In the liquid crystal label 210, the main portion 216 a of the background layer 216 may not be formed on the surface opposite to the base material 212 in the image line portions 216 b and 216 c. Thus, even if the main portion 216a of the background layer 216 is not formed on the image line portions 216b and 216c, the same effect can be obtained.
[0035]
Further, in this liquid crystal label 210, the entire background layer 216 may be formed of carbon black ink or non-carbon ink without forming the image portions 216b and 216c of the background layer 216. Thus, if the entire background layer 216 is formed of carbon black ink, the entire image of the CCD camera is darkened, and if the entire background layer 216 is formed of non-carbon ink, The entire image becomes brighter.
[0036]
Further, in the liquid crystal label 210, a part of the background layer 216 may be formed of non-carbon ink, and the remaining part may be formed of carbon ink. For example, if the right half of the background layer 216 of the liquid crystal label 210 is made of non-carbon ink and the left half is made of carbon ink, the right half of the image on the above-mentioned CCD camera becomes bright and the left half becomes dark. .
[0037]
Further, in this liquid crystal label 210, the color difference E ^* ab in the visible region between the main portion 216a of the background layer 216 and the image portions 216b and 216c may exceed 6. In this way, the image line portions 216b and 216c of the background layer 216 are easily identified under visible light. However, when the infrared light is irradiated and the reflected light is received by a CCD camera or the like, the main portion of the background layer 216 is obtained. Since the difference in the infrared absorptance between 216a and the image line portions 216b and 216c can be clearly seen, the accuracy of label authenticity discrimination can be improved as compared with the liquid crystal label 10 described above.
[0038]
In addition, this liquid crystal label 210 is also peeled between layers or partially when it is peeled off from the adherend after being attached to the adherend that is a genuine product, like the liquid crystal label 10 described above. In order to prevent the layer of the material from being broken and replaced with a fake, the following structure may be adopted.
That is, in each of the liquid crystal labels described above, the adhesive strength between the base material and the liquid crystal layer is weaker than the adhesive strength between the liquid crystal layer and the background layer, weaker than the adhesive strength between the background layer and the adhesive layer, and the liquid crystal layer, the background layer, and It is preferable that the adhesive layer is weaker than the cohesive fracture strength of each layer. If comprised in this way, when a liquid crystal label is peeled, it will peel between a base material and a liquid crystal layer, and it can prevent resticking without the whole peeling well.
Alternatively, in each liquid crystal label described above, the cohesive failure strength of the liquid crystal layer and / or the background layer of the liquid crystal layer, the background layer, and the adhesive layer is the same as that of the other layers of the liquid crystal layer, the background layer, and the adhesive layer. It is preferably configured to be weaker than the cohesive fracture 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. If comprised in this way, when a liquid crystal label is peeled, a liquid crystal layer and / or a background layer will be destroyed and the whole will not peel well, but it can prevent resticking.
Alternatively, in each liquid crystal label described above, 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 adhesive layer It is preferable that at least one of the cohesive failure strength of each of the layers excluding the cohesive failure strength of the liquid crystal layer and the cohesive failure strength of the background layer is configured to be weaker than the cohesive failure strength of the adhesive layer. If comprised in this way, when a liquid crystal label is peeled off, it will peel off between layers and / or a liquid crystal layer and / or a background layer will be destroyed, and the whole will not peel off well, but it will prevent reattachment be able to. In this case, the adhesive strength between each layer, 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 strength of each layer excluding the adhesive layer For example, two or more of the cohesive failure strength of the liquid crystal layer and the cohesive failure strength of the background layer may be formed equally.
[0039]
Convex characters and blank characters in each of the liquid crystal labels described above can be formed using gravure printing, flexographic printing, letterpress printing, screen printing, etc. It is preferable because it is easy to form clearly, and more preferably, it is formed by gravure printing.
[0040]
Further, the image portions 216b and 216c of the background layer 216 in the liquid crystal label 210 shown in FIG. 4 can also be formed by using gravure printing, flexographic printing, letterpress printing, screen printing, etc. Flexographic printing is preferable because it is easy to form a clear line, and more preferably, it is formed by gravure printing.
Further, the entire surface coating (solid) may be formed by any of the above-described printing methods, and can also be performed by a method such as a knife coater or a bar coater.
[0041]
In the description of the embodiment, the label continuous body in which a plurality of labels are formed on the separator has been described. However, the separator is not temporarily attached to the surface of the adhesive layer made of an adhesive, and the liquid crystal layer side of the substrate is On the opposite surface, a material with excellent releasability such as silicone is applied to form a release layer, the adhesive layer is the inside, and the surface on which the release layer of the base material is formed is the outside. It is good also as a label continuous body which can be returned and used.
[0042]
Moreover, the background layer should just be the thickness which the concealment effect produces, for example, 1 micrometer or more is preferable, Furthermore, about 2-5 micrometers is more preferable.
[Industrial applicability]
[0043]
According to the present invention, a liquid crystal label and a liquid crystal label that are flexible, easy to stick along the surface of the adherend, can be manufactured at a relatively low cost, and can be used as a label for preventing forgery. A continuum and a method for producing the same can be provided.
[Brief description of the drawings]
[0044]
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 continuum.
FIG. 4 is a cross-sectional view of a liquid crystal label according to another embodiment of the present invention.
5 is an illustrative plan view when the liquid crystal label shown in FIG. 4 is viewed under visible light. FIG.
6 is an illustrative view showing an image obtained by irradiating the surface of the liquid crystal label shown in FIG. 4 with infrared rays in the dark and capturing the reflected light from the surface side of the liquid crystal label with a CCD camera. FIG.
[Explanation of symbols]
[0045]
10, 210 Liquid crystal label 12, 212 Base material 14, 214 Liquid crystal layer 16, 216 Background layer 18, 218 Adhesive layer 20, 220 Separator

Claims (14)

A substrate having transparency or translucency;
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;
A liquid crystal label including an adhesive layer formed on a surface of the background layer opposite to the liquid crystal layer. The liquid crystal label according to claim 1, wherein the liquid crystal layer contains a liquid crystal composition composed of a cholesteric phase. The liquid crystal label according to claim 1, wherein the liquid crystal layer is partially formed on a back surface of the base material. The liquid crystal label according to claim 1, wherein a concealing layer is partially formed 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. . The liquid crystal label according to any one of claims 1 to 4, wherein the background layer has a portion having a difference in infrared absorption rate. 6. The liquid crystal label according to claim 5, wherein a portion provided with a difference in infrared absorption rate in the background layer is configured not to be identified under visible light. The strength of at least one of the adhesive strength between the layers and the cohesive failure strength of each layer excluding the adhesive layer is configured to be weaker than the cohesive failure strength of the adhesive layer. Liquid crystal label as described in. The adhesive strength between the substrate and the liquid crystal layer is weaker than the adhesive strength between the liquid crystal layer and the background layer, weaker than the adhesive strength between the background layer and the adhesive layer, and the liquid crystal layer, the background layer, and the The liquid crystal label according to claim 7, wherein the liquid crystal label is configured to be weaker than the cohesive fracture strength of each layer of the adhesive layer. Among the liquid crystal layer, the background layer, and the adhesive layer, the cohesive failure strength of the liquid crystal layer and / or the background layer is the aggregation of the other layers of the liquid crystal layer, the background layer, and the adhesive layer. Weaker than the breaking 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, The liquid crystal label according to claim 7. Adhesive strength between the substrate 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 cohesive failure strength of the background layer The liquid crystal label according to claim 7, wherein at least one of the strengths is configured to be weaker than the cohesive failure strength of the adhesive layer. A substrate having transparency or translucency, the surface of which has releasability;
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;
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 substrate as the outside and the adhesive layer as the inside. The label is
A substrate having transparency or translucency;
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;
An adhesive layer formed on a surface of the background layer opposite to the liquid crystal layer,
The label is a liquid crystal label continuous body temporarily attached to a separator on the surface of the adhesive layer opposite to the background layer. Forming a liquid crystal layer on the back side of the substrate having transparency or translucency;
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. The step of forming the liquid crystal layer includes
The liquid crystal layer forming coating liquid is applied to heat to a temperature at which a cholesteric phase can be formed to form a cholesteric phase, and UV irradiation is performed to UV-crosslink to fix the cholesteric phase. Liquid crystal label manufacturing method.

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