JP2010275452A - Gloss ink and laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gloss ink reflecting a circularly polarized light beam which can be verified by a circularly polarized light film and having bright and high luminance. <P>SOLUTION: The gloss ink contains a first pigment reflecting one circularly polarized light beam between left and right circularly polarized light beams and transmitting the other and a second pigment having specular reflectivity, or contains the first pigment reflecting one circularly polarized light beam between left and right circularly polarized light beams and transmitting the other, a second pigment having a color tone different from that of the first pigment and a polarization direction reverse to that of the first pigment and a third pigment having specular reflectivity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink composition capable of authenticating with a circularly polarizing film and a security device using the same.

  In recent years, as a measure to prevent counterfeiting of banknotes, gift certificates, credit cards, etc., and as proof of authenticity such as brand products and luxury products, changes in colors and images depending on the viewing angle of holograms, diffraction gratings, multilayer thin films, etc. OVD (Optically Variable Device) is often used. Alternatively, these OVDs are stacked or combined with a pearl pigment to improve design properties.

  These OVDs require advanced manufacturing technology, have a unique visual effect, and can be judged at a glance as authenticity, so they can be formed on credit cards, securities, certificates, etc. as part of or on the entire surface as an effective counterfeit measure. Is being used. Recently, in addition to securities, it is affixed to sports equipment, computer parts and other electrical products and software, etc., and authentication stickers that prove the authenticity of those products, and seal stickers that are affixed to the packages of those products Has come to be widely used.

  However, in recent years, with the widespread use of hologram production technology, rudimentary hologram images have been easily forged. On the other hand, the multilayer type OVD has become widely available in the field of packaging materials other than anti-counterfeiting applications, and thus has become easy to obtain, and its anti-counterfeiting effect has been lost.

  Therefore, there is a need for a new anti-counterfeiting technology capable of discriminating authenticity from the appearance of holograms and multilayer thin-film OVDs, and the present applicant discloses an example of a technology related to an anti-counterfeiting structure that can be easily visually identified (For example, refer to Patent Document 1).

  By the way, the structure having a helical structure such as a cholesteric liquid crystal also exhibits a metallic color, transmits circularly polarized light that rotates in the same direction as the direction of the spiral, and reflects circularly polarized light that rotates in the opposite direction. Have different optical properties. Therefore, the films coated with different cholesteric liquid crystals with different helical directions look the same in appearance, but cholesteric regions with different helical directions can be identified by observing with a circular polarizing film.

  That is, regions having different directions of spiral cannot be distinguished from each other in appearance, and can be identified by observing them through a circularly polarizing film, so that they can be used as security members for judging authenticity.

  However, the circularly polarizing ink containing the cholesteric liquid crystal polymer is visible by the circularly polarizing film and can be verified in that sense, but it is generally dark because it reflects only light polarized in either the left or right direction. Even if it is used for confirmation, there is a problem that the luminance is low.

  On the other hand, an ink containing a pigment (aluminum paste, pearl, OVI) having ordinary optical properties that reflects specularly has a feature of high brightness, although the hue changes depending on the viewing direction. However, it does not have an optical verification function like a cholesteric liquid crystal.

Japanese Patent Application No. 2007-272409

  Accordingly, an object of the present invention is to provide a glossy ink having an optical property of returning circularly polarized light that can be verified by a circularly polarizing film, and having high design properties and high reflection luminance.

  In order to achieve the above object, the invention according to claim 1 includes a first pigment that reflects one circularly polarized light of the left and right circularly polarized light and transmits the other circularly polarized light, and a second mirror having specular reflectivity. And a gloss ink characterized by containing a pigment.

  By setting it as the ink of this structure, high brightness | luminance is realizable, leaving the authenticity determination function by a circularly-polarizing film.

  According to a second aspect of the present invention, the first pigment that reflects one circularly polarized light of the left and right circularly polarized light and transmits the other circularly polarized light, and the second pigment having a color tone different from that of the pigment and having a polarization direction opposite to that of the first pigment. It is a gloss ink characterized by containing a pigment and a third pigment having specular reflectivity.

  By setting it as this structure, since the grade of circularly polarized light can be changed, it becomes an ink which can control the visibility by a circularly-polarizing film.

  The invention described in claim 3 is a laminate comprising an ink layer made of the ink of claim 1 or claim 2 on a part of the support.

  The invention according to claim 4 is the laminate according to claim 3, wherein a light absorbing layer is laminated on a part of the ink layer.

  By adopting such a configuration, it is possible to reduce the reflection from the base, and thus the luminance can be increased.

  The invention according to claim 5 is the laminate according to claim 4, wherein the light absorption layer is composed of a plurality of light absorption layer regions having different absorption characteristics in a non-visible wavelength region. .

  With such a configuration, the pattern is indistinguishable with the naked eye, but the pattern can appear with a scope capable of detecting infrared / ultraviolet rays.

  The invention according to claim 6 is the laminate according to any one of claims 3 to 5, further comprising an adhesive layer.

  The invention according to claim 7 is characterized in that at least a substrate, a release layer, the ink layer, a colored layer, and an adhesive layer are formed in this order. It is set as the laminated body of description.

  According to the present invention, it is possible to obtain bright and bright glossy ink while maintaining the authenticity determination function by the circularly polarizing filter. The laminated body which apply | coated this gloss ink also has the same effect.

It is sectional drawing explaining an example of a structure of the transfer foil which concerns on this invention.

  The glossy ink adjusting method according to the present invention and an example in which a laminate using the ink is applied to a transfer foil will be described. The present invention has a metallic gloss to a specular reflective ink such as a pearl pigment, and by adding a pigment having a selective reflectivity with respect to circularly polarized light, the brightness is further increased and the gloss and design properties are improved. You get good ink.

  Glossy ink is a specularly reflective first pigment (UV ultra pearl green; T & K TOKA is written to show what this is) 99 parts artificially exhibiting pearly luster, and flakes made of cholesteric liquid crystal polymer as the second pigment The mixture was prepared by mixing 1 part of a pigment, HELICONE HC SLM90120 (manufactured by Wacker Chemical Co.) and 20 parts of MEK as a diluent.

  A pigment made of a cholesteric liquid crystal polymer is a material that is made of a cholesteric liquid crystal structure that is three-dimensionally cross-linked and exhibits a color change depending on the viewing angle. This material is prepared by, for example, arranging a three-dimensional cross-linked polymer such as polyorganosiloxane having a methacryloyloxy group or an acryloyloxy group in the side chain and a liquid crystalline substance in parallel layers with respect to a base material. The thin film layer in which different molecular orientations are stacked in layers by an electric field or a magnetic field so as to have a helical structure is three-dimensionally cross-linked, and then separated from the substrate and pulverized to a desired size.

  Since the above pigment has a helical structure, the wavelength range of the spectrum to be reflected is determined by the pitch of the spiral and the refractive index of the material, and the reflected light of the spectral wavelength in a specific range has a helical structure with a pitch corresponding to the light wavelength. The light component is divided into polarized light components, and becomes a reflection component and a transmission component according to the rotation direction of the spiral. Since the change in the viewing angle facing the spiral structure changes the pitch of the spiral, the dichroism in which the color changes depending on the viewing angle is expressed.

  The weight ratio of the specular reflective first pigment and the circularly polarizing second pigment is appropriately selected within the range of 1:99 to 50:50. In addition to the cholesteric liquid crystal polymer, the circularly polarizing pigment can be prepared by crushing a linear polarizer laminated with a (¼) λ retardation plate.

  The pigment exhibiting circular polarization may be produced by mixing a right circular polarization pigment and a left circular polarization pigment. In this case, it is desirable to mix pigments having different hues of the respective pigments.

  In addition, an anti-settling agent, a leveling agent, a silicone or organic polymer surface conditioner, an ultraviolet absorber, or the like may be added to improve the properties of the ink.

  Next, a method for producing a transfer foil using the above glossy ink will be described. FIG. 1 is a cross-sectional view showing the configuration of the transfer foil.

  An acrylic release layer 2 having a thickness of 2 μm is formed on a PET film substrate 1 having a thickness of 16 μm by a gravure coating method.

  Next, a two-component curing type urethane resin is applied with a thickness of 1 μm by a gravure coating method. Subsequently, the hologram layer 3 is formed by embossing using a hologram plate at 200 ° C. Further, 50 nm of aluminum is deposited from above to form the reflective layer 4.

  Next, a predetermined pattern printing is performed on the mask ink 5 made of a vinyl chloride-vinyl acetate copolymer with a thickness of 1 μm by a gravure printing method.

  Next, the glossy ink layer 6 is formed by applying the above-described glossy ink to a thickness of 1 μm by a gravure coating method. Further, a black colored layer 7 made of a vinyl chloride-vinyl acetate copolymer in which carbon black is dispersed is applied with a thickness of 1 μm by a gravure coating method.

  Finally, an adhesive layer 8 made of a vinyl chloride-vinyl acetate copolymer in which a silica filler is dispersed is applied in a thickness of 2 μm by a gravure coating method.

The transfer foil thus produced was transferred so that the adhesive layer 8 was adhered to the base material, and the PET base material 1 was peeled off and observed by holding the left and right circularly polarizing films. When observed without using a circularly polarizing film, it was a color shift ink with high brightness.
When viewed with the right circular polarizing film, the reflected light from the cholesteric pigment could be confirmed. When observed with the left circularly polarizing film, it looked black because there was no reflected light.

  As an application example of the present ink, besides the transfer foil, the ink w is applied to one surface of a transfer foil having a structure basically the same as the above but having no hologram layer and a reflection layer, or a base film. In addition, a sticker having a simple configuration in which the other surface is subjected to adhesive processing, a paper sheet through which the laminate is transparent, and the like can be given.

DESCRIPTION OF SYMBOLS 1 ... PET base material 2 ... Release layer 3 ... Hologram layer 4 ... Aluminum reflective layer 5 ... Mask layer 6 ... Ink layer 7 ... Colored layer 8 ... Adhesive layer

Claims (7)

  A glossy ink comprising: a first pigment that reflects one circularly polarized light of left and right circularly polarized light and transmits the other circularly polarized light; and a second pigment having specular reflectivity.   A first pigment that reflects one circularly polarized light among the left and right circularly polarized light and transmits the other circularly polarized light, a second pigment that has a color tone different from that of the pigment and has a reverse polarization direction, and a specularly reflective first pigment. 3. A glossy ink comprising 3 pigments.   A laminate comprising an ink layer made of the ink according to claim 1 or 2 on a part of a support.   The laminate according to claim 3, wherein a light absorption layer is laminated on a part of the ink layer.   The laminate according to claim 4, wherein the light absorption layer includes a plurality of light absorption layer regions having different absorption characteristics in a non-visible wavelength region.   The laminate according to any one of claims 3 to 5, further comprising an adhesive layer.   The laminate according to any one of claims 3 to 5, wherein at least a substrate, a release layer, the ink layer, a colored layer, and an adhesive layer are formed in this order.

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