JP5476818B2 - Transfer sheet for authenticity identification - Google Patents

Description

The present invention relates to a transfer sheet for authenticity identification that makes it possible to distinguish between a sheet obtained by forgery or falsification based on an unauthorized intention and a genuine sheet .

(Main use) The main use of the authenticity identifier of the present invention is an authenticity identifier used in the field of anti-counterfeiting, specifically, when it is used by being counterfeited such as a credit card. Can cause damage to cardholders and card companies, driver's licenses, employee ID cards, ID cards such as membership cards, entrance examinations for entrance examinations, passports, banknotes, gift certificates, point cards, stock certificates, There are securities, lottery tickets, horse betting tickets, bankbooks, boarding tickets, pass tickets, air tickets, admission tickets for various events, play tickets, prepaid cards for transportation and public telephones.
Each of these is an information recording body that holds information having economic or social value, and it is desirable to have a function that can identify the authenticity of the recording body for the purpose of preventing damage caused by forgery. .

In addition to these information recording media, expensive products such as luxury watches, luxury leather products, precious metal products, jewelry, etc., often referred to as luxury brand products, or storage of such expensive products. Boxes and cases can also be forged. In addition, mass-produced products of famous brands, such as audio products, electrical appliances, etc., or tags that are hung on them are also subject to forgery.
Furthermore, a storage body in which music software, video software, computer software, game software, or the like, which is a copyrighted work, or cases thereof can also be forged. In addition, it is desirable that products such as printer toner, paper, and the like in which supplies to be replaced are limited to genuine materials have a function of identifying their authenticity for the purpose of preventing damage caused by forgery.

(Background technology)
Conventionally, for the purpose of preventing counterfeiting of information recording bodies and various articles described above (collectively referred to as authenticity identification objects), it is said that they have manufacturing difficulties due to the precision of their structures. In many cases, holograms are applied as authenticity distinguishable. However, since the hologram manufacturing method itself is known and can be precisely processed by that method, when the hologram is merely for visual judgment, there is no difference between a genuine hologram and a forged hologram. It is difficult to distinguish.
These authentic identification objects, in particular, articles that have been subjected to hologram images in a label form or transfer form, are not only used for authentic identification of visual confirmation of hologram images, but also by using a new authenticity identification method. There is a need to identify the authenticity of.

(Prior art)
In order to meet these requirements, an authenticity identifier having a light selective reflection layer that reflects only one of the left-handed polarized light and the right-handed polarized light in the incident light, and the light selective reflective layer thereof. And an authenticity discriminator in which holograms are laminated. As this light selective reflection layer, cholesteric liquid crystal is used, and the anti-counterfeiting property is enhanced by a method of confirming using a polarizing plate or the like.
(For example, see Patent Document 1 and Patent Document 2.)
However, even if the anti-counterfeiting property by the hologram and the authenticity determination by the cholesteric liquid crystal are laminated and a visual effect of color change and reproduction of the hologram image is obtained, the authenticity determination is performed by using a special polarizing plate. An authenticity determination device is necessary, and the determination work is complicated, such as providing the device in a scene where determination is performed, and taking out and using the device in that scene.

JP 2000-25373 A JP 2007-90538 A

Accordingly, the present invention has been made to solve such problems. Its purpose is
It is an object to provide an authenticity identification body that does not require a special authenticity determination instrument or the like for authenticity determination and that can easily and accurately identify authenticity visually.

In order to solve the above-described problems, the first aspect of the authenticity identification transfer sheet of the present invention is an authenticity comprising an authenticity identifier (also referred to as an authenticity identification medium) including at least a cholesteric liquid crystal layer and a colored layer. A transfer sheet for identification,
A release layer, a cholesteric liquid crystal layer, a colored layer, and an adhesive layer are laminated on one surface of the transparent substrate,
Color changes according to the angle of the cholesteric liquid crystal layer is observed, and the colored layer is different from a color tone, a plurality of regions that are not contact, each of the color tone, its spectral characteristics, A region that is the same as the spectral characteristics of light reflected from the cholesteric liquid crystal layer at different predetermined observation angles, and is visible at the observation angle when the color tone of the cholesteric liquid crystal layer changes according to the observation angle. it is characterized in that it has two patterns or shapes pattern formed by.
The cholesteric liquid crystal layer changes its color tone from “red” to “green” and further to “blue” depending on the viewing angle. (This means that the selectively reflected light changes.) This change is “continuous” in the sense that the spectral characteristics change continuously, and gradually changes as the observation angle is gradually changed.
When a colored layer is partially provided on this cholesteric liquid crystal layer, the spectral characteristics of the colored layer are the same as the light reflected from the cholesteric liquid crystal layer (the spectral distribution of reflected light expressed by the wavelength distribution of reflected light and its intensity). If the characteristic is the same), the “boundary” of the “pattern displayed by the colored layer” (the end of the colored layer forming portion) cannot be visually recognized, and only a cholesteric liquid crystal layer having a single color tone. Recognize that there is.

This “pattern to be displayed (also referred to as a display pattern)” means characters, figures, symbols, and the like expressed by the “formed shape” of the colored layer.
When the above observation angle is slightly shifted, the spectral characteristics of the reflected light of the cholesteric liquid crystal layer change (a different color tone), which is different from the spectral characteristics of the colored layer. A contrast such as a color difference is generated between the cholesteric liquid crystal and the “displayed pattern” of the colored layer can be easily recognized visually.
For example, when the color tone of the cholesteric liquid crystal layer is “red”, the “red colored layer” having the same color tone as the “red” exhibits the phenomenon described above.
Conversely, “green” and “blue”, which are contrasting colors (complementary colors, etc.) to “red” of the cholesteric liquid crystal layer, or a mixed color thereof (“blue-green”. Complementary colors) are used. When the layer is formed, the pattern displayed on the colored layer can be clearly recognized visually.
That is, when the selectively reflected light of the cholesteric liquid crystal layer is “red”, the “display of one character, figure, etc. (first display pattern)” by the “green” and “blue” coloring patterns. When the selectively reflected light of the cholesteric liquid crystal is “green”, the “red” and “blue” coloring patterns indicate “display of another character, figure, etc. (second display pattern) In addition, when the selectively reflected light of the cholesteric liquid crystal layer exhibits “blue”, the “red” and “green” coloring patterns indicate that “ another character, figure, etc. 3 display pattern) ”, the display is switched to (first display pattern), (second display pattern), and (third display pattern) as the observation angle is gradually changed. That is, each display pattern becomes “a pattern combined with green and blue”, “a pattern combined with red and blue” and “a pattern combined with red and green”. The “blue” and “red” patterns are common, and three different patterns are displayed by three combinations of two of them.

This switching occurs only when the above-described spectral characteristic of each colored layer matches the spectral characteristic of the selectively reflected light of the underlying cholesteric liquid crystal layer (that is, the boundary line of one color portion is completely Only when it disappears.) When viewed from the observation angle, it becomes a very narrow range (within 10 degrees as the observation angle).
At other observation angles, the display from the first display to the third display is mixed, and it is difficult to recognize individual displays.
In order to perform authenticity determination, it is necessary that two predetermined display patterns appear at at least two predetermined observation angles. Of course, as described above, three predetermined display patterns may appear at three predetermined observation angles.
When the switching display pattern is 3 or more, the combination of the display patterns (the entire display pattern) becomes complicated, and each switching pattern (one of the three display patterns is “(green) + (blue ) ”And“ (red) + (blue) ”, which form a different display pattern, etc.) are difficult to infer from among the complicated ones. However, if the number of display patterns exceeds six, the angle difference between the display pattern and the display pattern is about 10 degrees, so that the contrast is small and the sharpness is lost. Inconvenience such as too much information to be generated.
In order to improve anti-counterfeiting, the switching screens are set one by one in the “vertical direction (0 degree)” and “20 degrees” directions, and are further spaced at an angle of “80 degrees”. Introducing unexpectedness such as setting the third one is also desirable from the viewpoint of preventing counterfeiting.

Since it is necessary to clearly and surely confirm these displays, it is also preferable to form a plurality of cholesteric liquid crystals having selective reflectivity “close” to the spectral characteristics of each colored layer. That is, when the cholesteric liquid crystal layer in which the selective reflected light with respect to a predetermined observation angle is shifted by about 10 nm to 50 nm as the “wavelength” is laminated, the width of the spectral characteristic curve of the selectively reflected light of the laminate can be expanded. Since the observation angle range showing the same color tone can be expanded, stable authenticity determination can be performed.
A cholesteric liquid crystal layer that reflects certain selectively reflected light strongly reflects light of a specific wavelength and transmits light having a wavelength shifted by several tens of nanometers or more from that wavelength. When the second cholesteric liquid crystal layer with the reflected light wavelength shifted by several tens of nanometers is formed, the reflected light with the shifted wavelength is selectively reflected from this layer (through the upper layer). When observed as a two-layer laminate, it is recognized as if the spectral characteristics of the selectively reflected light were summed, that is, the width of the reflected wavelength was widened in the reflected light intensity-wavelength curve. From such a principle, even if the wavelength of the selective reflection layer of the cholesteric liquid crystal layer is gradually shifted (for example, 20 nm) as a multilayer (for example, 5 layers) and the width is set to 100 nm or more, the selection of the lowermost layer is selected. The intensity of the reflected light can be observed without attenuation.

The cholesteric liquid crystal layer may itself be formed in a pattern that represents characters, figures, symbols, and the like.
For the colored layer, natural inorganic pigments: brown pigments such as amber and senna, calcium carbonate, kaolin, pearl pigments, etc., synthetic inorganic pigments: white pigments (zinc white, lead white, titanium dioxide), red pigments (lead red) , Iron oxide red), yellow pigment (yellow lead, chrome yellow, zinc yellow), blue pigment (ultramarine blue, prussian blue), etc., ceramic pigment, azo pigment, polycyclic pigment: quinancridon, perinone, quinophthalone , Phthalocyanine, indanthrene, quinacridone, and the like, lake pigments: lake red C, woochueng red, etc., natural dyes: akane, eye, turmeric, etc., synthetic dyes: alizanin, indigo and the like. The concentration of the colored layer is preferably adjusted to be uniform according to the intensity of the reflected light from the cholesteric liquid crystal layer.

A pigment having color variability, such as a pearl pigment, has an effect of changing the spectral characteristics of the reflected light of the colored layer (for example, the reflected light wavelength can be widened to increase the angle at which the color tone is synchronized). It is suitable for adjusting the screen switching performance.
As a method for forming the colored pattern layer, an appropriate method can be used for the formation pattern, such as an offset printing method, a gravure printing method, and a screen printing.
However, in order to form a fine pattern such as a halftone dot having a size of several tens of μm to several mm, a stainless screen printing method that has high printing position accuracy and does not cause bleeding of the printing pattern is desirable. The thickness to be formed depends on the pigment content of the colored ink and the like, but is preferably determined in synchronism with the selectively reflected light.

The situation in which the “display pattern” is switched will be described in the case of three display patterns. The cholesteric liquid crystal layer is represented by CL, the red colored layer is represented by “red”, the green colored layer is represented by “green”, and the blue colored layer is represented by “blue”. Sometimes, the color layers of each color are arranged in a “bar shape”, and when the color can be recognized as “ CL / red / CL / green / CL / blue / CL / red / CL ” from the observation side, the color tone of CL changes. Then, it is visually recognized as a “wide bar” (wide red, wide blue, etc.) or “narrow bar” (narrow red, narrow blue, etc.) exhibiting each color.
(1) When CL is red,
“/ Red / Red / Red / Green / Red / Blue / Red / Red / Red /”
That is,
"/ Wide red / Narrow green / Narrow red / Narrow blue / Wide red /"
(2) When CL is green,
“/ Green / Red / Green / Green / Green / Blue / Green / Red / Green / ”
That is,
"/ Narrow green / Narrow red / Wide green / Narrow blue / Narrow green / Narrow red / Narrow green /"
(3) When CL is blue,
"/ Blue / Red / Blue / Green / Blue / Blue / Blue / Red / Blue / "
That is,
"/ Narrow blue / Narrow red / Narrow blue / Narrow green / Wide blue / Narrow red / Narrow blue /"
It becomes. If these are so-called barcode patterns, the data that can be read differs depending on the observation angle. Of course, it can be used for any other optical recognition method such as a two-dimensional barcode.
Further, when the colored layer is observed through the cholesteric liquid crystal layer, the situation is slightly different from the above. That is, a part of the light from the white light source is first reflected by the cholesteric liquid crystal layer, and the remaining light is transmitted to reach the colored layer. The colored layer is usually “subtractive color mixing” (of course not pearl pigments, etc.), partially absorbing the observation light and reflecting the rest of the light, and the color tone of the reflected light is that of the colored layer. It becomes a color tone. Therefore, in order for the color tone of the cholesteric liquid crystal at a certain observation angle and the color tone of the colored layer behind it to be “same”, the right circularly polarized light or the left circularly polarized light that has passed through the cholesteric liquid crystal (same as the reflected light) The colored layer reflects the reflected light and the circularly polarized light), and the colored layer needs to absorb all other light. Accordingly, the brightness of the colored layer is halved by being positioned below the cholesteric liquid crystal layer, and is more easily tuned.
Of course, the cholesteric liquid crystal layer and the colored layer can be formed in parallel without overlapping, but in that case, the boundary between the cholesteric liquid crystal layer and the colored layer, that is, the boundary line portion is processed by processing. Since the line becomes easy to see, special processing such as “blurring processing” (processing such as reducing the thickness of each layer in the boundary line region or forming the layers alternately and finely), “halftone processing” ( Only the boundary part makes each layer inconspicuous as a halftone dot.) Or, “high-precision alignment” at the submicron level is performed as in a photoresist system.
In any case, how the cholesteric liquid crystal having viewing angle dependency and the colored layer having omnidirectionality appear at a predetermined viewing angle (meaning not only color tone but also color, density, etc.). In order to approach “same”, not only superimposition of the spectral characteristics for each observation angle of the cholesteric liquid crystal and the spectral characteristics of the colored layer, but also various measures such as adjusting the thickness and density of each layer are implemented.
In particular, when observation light such as a “three-wavelength tube” that is generally used as an illumination light source is observed in a discrete manner, the present invention is based on the combined effect of the discreteness and the spectral characteristics of reflected light. The effect of can be made more effective.

Authenticity identification transfer sheet of the present invention, as a layer structure, a transparent substrate / release layer / colored layer / cholesteric liquid crystal layer / adhesive layer, the release layer and, by providing the adhesive layer, and the transcription sheet form can do. Of course, it can also be set as transparent substrate / release layer / cholesteric liquid crystal layer / colored layer / adhesive layer.
That is, in the second aspect of the authenticity identification transfer sheet of the present invention, the layer configuration is transparent substrate / peeling layer / colored layer / cholesteric liquid crystal layer / adhesive layer.
For the release layer and the adhesive layer described in the first and second aspects, a release agent and an adhesive used for a normal transfer sheet can be used. When the display pattern is observed through each layer, It is preferable to use a material having high optical transparency.
When the transfer sheet for authenticity identification of the present invention is in the form of a transfer sheet, it can be easily applied to an authenticity identification object.

According to the transfer sheet for authenticity identification of the present invention, the anti-counterfeiting property is superior to a simple laminate of cholesteric liquid crystal layers, the design is improved, the authenticity can be easily identified by visual observation , and the authenticity identification is performed. Application to an object becomes easy.

It is a cross-sectional view of the authenticity identifying objects A1 showing an embodiment of the authenticity identifying objects. It is a cross-sectional view of the authenticity identifying objects A2 showing another embodiment of the authenticity identifying objects (labeled form). Real施例of the present invention (transfer sheet form) is a sectional view of the authenticity identifying objects A3 shown.

(Transparent substrate)
The transparent substrate 1 used in the present invention can be made thin, and has mechanical strength and solvent resistance and heat resistance that can withstand processing when manufacturing the authenticity identifier A1 to A3. Those are preferred. Since it depends on the purpose of use, it is not limited, but a film-like or sheet-like plastic is preferable.
For example, various plastic films such as polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose (TAC), diacetyl cellulose, and polyethylene / vinyl alcohol can be exemplified. .
The thickness of the transparent substrate 1 is usually 5 to 250 μm, but in the case of a label form or a transfer sheet form, it should be 5 to 100 μm, particularly 10 to 50 μm, taking into account its processing suitability. desirable.

(Cholesteric liquid crystal)
The cholesteric liquid crystal layer 2 used in the present invention only needs to have light selective reflectivity, and further, light selection that reflects either left circularly polarized light or right circularly polarized light with respect to incident light from the observation side. It may be reflective. Also, by applying these in combination, the determination method can be complicated, and a more sophisticated authenticity identifier can be obtained.
Cholesteric liquid crystals include cholesterol halides, monocarboxylic acid cholesterol esters, monocarboxylic acid sitosterol esters, benzoic acid derivative cholestanol esters, dibasic acid dicholesteryl esters, main chain liquid crystal polymer compounds, side chain liquid crystal polymers Examples thereof include molecular compounds and rigid main chain type liquid crystal polymer compounds.

More specifically, for example, cholesteryl chloride, cholesteryl acetate, cholesteryl nonanoate, methyl carbonate, ethyl cholesterol, cholesteryl p-methoxybenzoate, sitosteroyl benzoate, sitosteroyl p-methyl benzoate, cholestanyl benzoate, 10, 12- Docosadiin dicarboxylic acid dicholesteryl ester, 8,12-eicosadicarboxylic acid dicholesteryl ester, 10,12-pentacosadiin dicarboxylic acid dicholesteryl ester, dodecadicarboxylic acid dicholesteryl ester, 12,14-hexacosadiin dicarboxylic acid Dicholesteryl ester, 4- (7-cholesteryloxycarbonylheptyloxy) phenoxyoctanoic acid cholesteryl ester, L-glu Min acid -γ- benzyl / L-glutamate -γ- dodecyl copolymers and the like.
Further, cholesteryl formate, cholesteryl acetate, cholesteryl propionate, cholesteryl butyrate, cholesteryl pentanate, cholesteryl hexanate, cholesteryl heptanoate, cholesteryl octanate, cholesteryl nonanoate, cholesteryl decanate, cholesteryl decanate (cholesteryl laurate) Cholesteryl myristate, cholesteryl palmitate, cholesteryl stearate, cholesteryl oleate, cholesteryl oleyl carbonate, cholesteryl linoleate, cholesteryl 12-hydroxystearate, cholesteryl mercaptan, cholesterol chloride, cholesteryl fluoride, cholesteryl bromide, cholesteryl iodide, etc. Can be mentioned.

Preferably, a mixture of three kinds of alkyl cholesterol (for example, cholesterol nanoate) and cholesteryl halide (for example, cholesterol chloride) cholesteryl oleyl carbonate is used, and these three types of liquid crystals are used so as to be used at room temperature. Is common.
In addition, it is not limited to the compound shown here, Moreover, these cholesteric liquid crystal compounds can be used 1 type or in mixture of 2 or more types.
As a liquid crystal compound in which a chiral compound is added to a nematic liquid crystal compound, 4-substituted benzoic acid 4′-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4′-substituted phenyl ester, 4-substituted cyclohexane Carboxylic acid 4′-substituted biphenyl ester, 4- (4-substituted cyclohexanecarbonyloxy) benzoic acid 4′-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4′-substituted phenyl ester, 4- (4- Substituted cyclohexyl) benzoic acid 4'-substituted cyclohexyl ester, 4-substituted 4'-substituted biphenyl, 4-substituted phenyl 4'-substituted cyclohexane, 4'-substituted cyclohexane, 2- (4-substituted phenyl) -5-substituted pyridine For example, “Palio Color LC242” (manufactured by BASF And the like can be used.
Particularly preferably, a liquid crystal compound having a cyano group or a fluorine atom at least at one end of the molecule is used, and various suitable chiral agents are added to these liquid crystal compounds. As the chiral compound, “CB-15”, “C-15” (manufactured by BDH), “CM-21”, “CM-22”, “CM-19”, “CM-20”, “CM” (Above, manufactured by Chisso Corporation), "S1082", "S-811", "R-811" (above, manufactured by Merck), "Palio Color LC756" (produced by BASF), and the like.
Further, a cholesteric liquid crystal having no cholesterol group in which a group having an asymmetric carbon is introduced into a terminal group of a nematic liquid crystal obtained by organic synthesis, or a mixed liquid crystal in which a Schiff nematic liquid crystal is added to a cholesterol derivative is also used. Furthermore, halogen substitution products and esterified products of natural cholesterol (cholesteryl benzoate, cholesteryl chloride, cholesteryl oleate, cholesteryl nonanoate, and the like are also suitable.

As a method for providing these cholesteric liquid crystals, they can be formed using a normal printing method or coating method as a solvent-based, water-based, or solvent-free system. More preferably, the synchronism of the formation position can be enhanced by using the same means as the colored pattern layer forming method. When the same pattern is formed, the plate making method can be the same. In particular, after the colored pattern layer is provided on the transparent substrate, this position can be used as a timing mark (print positioning mark) to form a liquid crystal layer.
Alternatively, the liquid crystal may be formed using an ink encapsulated with a resin film such as gelatin. The encapsulated product has excellent physical properties (toughness, wear resistance, heat resistance, etc.) as well as workability at the time of manufacture, and prevents problems such as liquid seepage, and is used in the present invention. It is particularly suitable for the required hygiene.
The shape and thickness of the cholesteric liquid crystal layer 2 need to be appropriately optimized according to the purpose of use of the authenticity identifier. Furthermore, since it can be set to several tens of μm as a hidden character like a micro character, the thickness corresponding to each individual, that is, from several μm to 50 μm, while maintaining selective reflectivity, It shall be optimal.

When the cholesteric liquid crystal layer 2 is provided, an alignment process such as providing the following alignment film may be performed in advance. Any alignment film may be used as long as it can be generally used as an alignment film, such as polyvinyl alcohol resin (PVA) or polyimide resin. The alignment film is formed by applying a solvent solution of these resins to the surface of the layer forming the cholesteric liquid crystal layer 2 by an appropriate application method and drying, followed by rubbing with a cloth, a brush, or the like. To do.
The color tone of the cholesteric liquid crystal layer 2 changes depending on the viewing angle, but since the state of the change is theoretically determined, the viewing angle that is the same as that of the colored layer 3 of the present invention is considerably narrow.
There are the following two methods for enlarging the same range with respect to the observation angle.
One is a method of changing the spectral characteristics of the cholesteric liquid crystal layer. When the cholesteric liquid crystal layers with slightly different peak values of selective reflected light are overlapped and the observation angle is changed, the top layer and the next layer are changed. Furthermore, by designing the next layer to exhibit the same color tone as that of the colored layer 3, the reflected light from the cholesteric liquid crystal layer can maintain its peak value.

This can be realized by laminating a cholesteric liquid crystal layer having a shift of about 10 nm to 50 nm in the peak value. Specifically, 10 μm each of the cholesteric liquid crystal layer having a reflected light of 650 nm and the same 670 nm is laminated on a cholesteric liquid crystal layer having a viewing angle of 0 degree and a red color of reflected light of 630 nm.
When this laminate is observed at an observation angle of 0 degrees, red reflected light of 600 nm to 690 nm is observed. Even if the observation angle is shifted by 10 degrees, the color tone of the colored layer 3 is still maintained, and the first display pattern Continue to be displayed.
The same device can be devised for other color tones, and the display pattern can be reliably recognized.
Another method is a method of changing the spectral characteristics of the colored layer 3, and the pigment used for the colored layer 3 is composed of a plurality of pigments close to the peak wavelength, or depending on the reflection angle like a pearl pigment. There is a method of adding a pigment that changes the color tone to follow the color tone change of the cholesteric liquid crystal layer.
In any case, in order to widen the angle range in which each display pattern can be recognized, it is necessary to widen the range in which the reflected light wavelength observed from the cholesteric liquid crystal layer 2 and the reflected light from the colored layer 3 are the same. is there.
Furthermore, in the above description, the specific example is described using the word “same” as “the spectral characteristics of reflected light etc. are the same”. The effect of the present invention can be sufficiently achieved even when the permissible range is expanded to “a degree that cannot be discriminated by“, ”or“ a degree that each display pattern can be recognized ”.

(Colored layer)
In the present invention, the colored layer 3 is formed on the cholesteric liquid crystal layer 2 or the like, or in the form of a transfer sheet, on the release layer 5 or the like.
As a pigment used in the colored layer,
Organic pigments such as quinacridone red / magenta, anthraquinone red / yellow, polyazo yellow, benzimidazolone yellow / orange, phthalocyanine pigments such as copper phthalocyanine blue (α type, β type), copper phthalocyanine green, different types Metal phthalocyanine blue, selenium blue, and azo pigments include soluble azo pigments (Carmine 6B, permanent red 2B, etc.) and insoluble azo pigments (disazo, monoazo, etc.).
Examples of inorganic pigments include complex oxide pigments, fine particle complex oxide pigments, bitumen, and hybrid pigments. In addition, petals, molybdenum red, cadmium red, red lead (and above, red), and yellow lead. (Red mouth), molybdenum orange (orange), cadmium orange (orange), ultramarine blue, ultramarine blue, bitumen, cobalt blue, cerulean manganese blue (above, blue), amber (brown) , Yellow lead, cadmium yellow, titanium yellow, yellow iron oxide (above, yellow), chromium oxide, cobalt green, viridian, peacock (above, green.), Mars purple, cobalt violet, manganese violet (above, purple.) In addition, extender pigments, metal powder pigments and the like are used.

The particle diameter of the pigment is usually 0.01 μm to 10 μm, but 0.01 to 0.1 μm is also transparent and has a property of partially transmitting the color tone of the cholesteric liquid crystal layer 2. Show. However, those having this particle size are liable to agglomerate and need to be redispersed. The addition amount is determined by the balance with the thickness formed by an appropriate formation pattern formation method such as an offset printing method, a gravure printing method, etc., but usually 10% to 50% addition is preferable, dissolved in an appropriate solvent, It is formed to a thickness of 2 to 20 μm.
Since the dye is also partially transparent, it is affected by the color tone of the cholesteric liquid crystal layer 2, and therefore it is desirable to design it including the influence. In any case, those excellent in dispersibility and solubility with the resin used can be used.
After the colored layer 3 is formed, the surface of the colored layer 3 can be roughened by heating and pressing with a metal stamper having irregularities with a surface roughness of 1.0 μm or more. In addition to this colored pigment, the colored pattern layer can also be roughened by using extender pigments such as calcium carbonate and titanium dioxide having a particle size of 1.0 μm or more. By this roughening, the characteristics of the reflected light of the colored layer 3 can be changed and adjusted.
The resin used for the colored layer 3 is acrylic resin, polyester resin, polyurethane resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, melamine resin, phenol. Examples thereof include resins, and those having good adhesion to the cholesteric liquid crystal layer 2 and the release layer 5 and those having good dispersibility of pigments and dyes can be used. Other additives are used as appropriate.

(Adhesive layer, adhesive layer and release layer)
Further, the authenticity identifier of the present invention is further applied with a pressure-sensitive adhesive (pressure-sensitive adhesive layer 4) to form a label, or a release agent and an adhesive (peeling layer 5, adhesive layer 4.) to form a transfer sheet. You can also.
In this case, as the pressure-sensitive adhesive, any conventionally known solvent-based or water-based pressure-sensitive adhesives such as vinyl acetate resin, acrylic resin, vinyl acetate-acrylic copolymer, vinyl acetate-vinyl chloride copolymer, ethylene-acetic acid are used. Examples include vinyl copolymers, polyurethane resins, and rubber resins such as natural rubber and chloroprene rubber.
Natural latex such as natural rubber latex, natural rubber latex obtained by graft polymerization of natural rubber with styrene, especially methacrylic acid methyl, in particular, to make natural material composition What was produced from the raw material may be used and formation thickness, a formation method, etc. are selected suitably.
The release layer preferably has a property of peeling from the transparent substrate, is excellent in adhesion to the colored layer 3 and is excellent in durability, and is selected from an acrylic resin, a polyester resin, a polyurethane resin, and the like. It is also preferable to add silicon resin fine particles having transparency and durability.
Further, since the adhesive is used to ensure the adhesiveness to various articles, an adhesive that has good adhesiveness to the cholesteric liquid crystal layer 2 and the like and can adhere firmly to the adherend is preferable. Specific examples include vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, acrylic resins, polyester resins, polyurethane resins, polyamide resins, and rubber-modified products. Appropriately selected from the above can be used, and these can be used alone or in a mixture of two or more, and if necessary, hard resin, plasticizer, and other additives can be added and used. The formation thickness, the formation method, and the like are appropriately selected.

Example 1
As a transparent substrate 1, a 5 μm thick cholestic liquid crystal layer 2 was formed on the surface of a 25 μm PET film by gravure printing, and then cured with UV rays.
・ <Cholesteric liquid crystal composition>
Bicolor LC242 37 parts by weight Bicolor LC756 2 parts by weight UV polymerization initiator 1 part by weight Toluene 60 parts by weight A colored pattern layer (red) having a thickness of 5 μm is formed on the colored layer 3 having the following composition. The first display pattern “star mark” and the blue second display pattern “moon mark” are respectively formed.), And authenticity determination identifier A1 is obtained.
・ <Coloring pattern composition>
The melamine resin Resin composition 30 parts by mass Petal or ultramarine 10 parts by mass extender pigment 5 parts by mass Toluene 55 parts by mass When the obtained authenticity identifier A1 is viewed from the observation side, at an observation angle of 0 degrees, At the same time that the cholesteric liquid crystal layer 2 of “red” was seen, the second display pattern “moon mark” of “blue” was seen. Further, when the observation angle was 60 degrees, the “blue” cholesteric liquid crystal layer 2 with a ☆ mark was seen, and at the same time, the first display pattern “star mark” with “red” was seen.
From the above, it was possible to easily determine that the authenticity discriminating object A1 as a target is “authentic”.
The spectral characteristics of the cholesteric liquid crystal and each colored layer at an observation angle of 0 ° and an observation angle of 60 ° are similar, and the effect is remarkable under a “three-wave tube” that is generally used as illumination light. .

(Example 2)
Example 2 was obtained in the same manner as Example 1 except that the colored layer 3 was added with a green pigment “cobalt green” forming layer to form first to third display patterns.
Each display pattern was “red”, “green”, and “blue” mosaic alphabet characters, and adjusted to display different alphabet characters in three combinations.
When the obtained authenticity identifier is viewed from the observation side, the “red” cholesteric liquid crystal layer 2 marked with a ☆ mark can be seen at the observation angle of 0 degree, and at the same time, the first displayed with “green” and “blue” mosaics. If the display pattern is visible and the observation angle is changed to 35 degrees, the “green” cholesteric liquid crystal layer 2 with a ☆ mark can be seen, and at the same time, the second display pattern displayed with “red” and “blue” mosaics can be seen. Further, when the observation angle is 45 degrees, a hologram image “star mark” having the same color tone as the observation light can be confirmed, and when the observation angle is 70 degrees, the “blue” cholesteric liquid crystal layer 2 with a ☆ mark can be seen, A third display pattern displayed with “red” and “green” mosaics was seen, and the same effect as in Example 1 was obtained.
From the above, it was possible to determine that the target authenticity discriminator is “authentic” easily and accurately by visual inspection.

(Example 3)
The authentic identification medium was the same as in Example 1 except that the following composition was coated with a gravure coater so that the coating amount after drying was 20 μm and dried at 70 ° C. to form the adhesive layer 4. A2 was obtained.
・ <Adhesive composition>
Vinyl acetate-acrylic copolymer 30 parts by mass Toluene 40 parts by mass Vinyl acetate 40 parts by mass This authentic identification medium A2 (label form) was attached to a passport.
When the authenticity identifier A2 on the passport was observed, the same effect as in Example 1 was obtained, and it was determined that this passport was “authentic”.
Example 4
On the transparent substrate 1, the following composition was applied with a gravure coater so that the coating amount after drying was 2 μm, and dried at 70 ° C. to form a release layer 5,
・ <Peeling agent composition>
Acrylic resin 20 parts by weight Fine particle microsilica (average particle size 0.016 μm) 0.1 part by weight Toluene 40 parts by weight Vinyl acetate 40 parts by weight On top of that, the colored layer 3, the cholesteric liquid crystal layer 2 and the following composition are gravure An authenticity identification medium A3 was obtained in the same manner as in Example 1 except that the adhesive layer 4 was formed by coating and drying at 70 ° C. so that the coating amount after drying with a coater was 5 μm.
・ <Adhesive composition>
Vinyl chloride-vinyl acetate copolymer 20 parts by mass Acrylic resin 20 parts by mass Extender pigment 10 parts by mass Toluene 20 parts by mass Vinyl acetate 30 parts by mass This authentic identification medium A3 (transfer sheet form) is superimposed on a passport, and 120 ° C. After heating and pressing for 10 minutes, the transparent substrate 1 was peeled off and transferred.
When the authenticity identifier A3 on the passport was observed, the same effect as in Example 1 was obtained, and it was determined that this passport was “authentic”.

(Comparative example)
As the colored layer 3, a comparative example was obtained in the same manner as in Example 1 except that only red printing was used.
When this was observed, the “red” cholesteric liquid crystal layer 2 marked with a ☆ mark was only visible at an observation angle of 0 °. When the observed angle was slightly changed to 10 degrees, the “red” colored layer 3 could be confirmed, and thereafter the colored layer 3 could be confirmed.
From the above, I felt that there was some anxiety in judging that it was “authentic”.

A1 Authenticity identifier A2 Authenticity identifier (label form)
A3 authenticity identifier (transfer sheet form)
1 Transparent substrate 2 Cholesteric liquid crystal layer 3 Colored layer 4 Adhesive layer (or adhesive layer)
5 Release layer

Claims (2)

A transfer sheet for authenticity identification in which a release layer, a cholesteric liquid crystal layer, a colored layer, and an adhesive layer are formed in this order on one surface of a transparent substrate,
The color tone changes according to the angle observed by the cholesteric liquid crystal layer,
and,
The colored layer is different from a color tone, a plurality of regions that are not contact,
Each of the color tones has the same spectral characteristics as the spectral characteristics of light reflected from the cholesteric liquid crystal layer at different predetermined observation angles,
Depending on the viewing angle, the cholesteric when the color tone of the liquid crystal layer is changed, authenticity identification transfer sheet characterized by having a shape pattern formed by visible region in the viewing angle 2 patterns more. A transfer sheet for authenticity identification in which a release layer, a colored layer, a cholesteric liquid crystal layer, and an adhesive layer are formed in this order on one surface of a transparent substrate,
The color tone changes according to the angle observed by the cholesteric liquid crystal layer,
and,
The colored layer is different from a color tone, a plurality of regions that are not contact,
Each of the color tones has the same spectral characteristics as the spectral characteristics of light reflected from the cholesteric liquid crystal layer at different predetermined observation angles,
Depending on the viewing angle, the cholesteric when the color tone of the liquid crystal layer is changed, authenticity identification transfer sheet characterized by having a shape pattern formed by visible region in the viewing angle 2 patterns more.

Images