JP4528935B2 - Printed material for authenticity determination using ink composition - Google Patents

Description

  The present invention relates to an ink composition comprising a single or a plurality of infrared light absorbing materials having at least two absorption bands and at least one reflection band in an infrared light absorption spectrum.

  Valuables such as banknotes, passports, securities, cards, stamps, and product tags are required to be difficult to counterfeit or tamper by nature. In order to prevent counterfeiting, an infrared light absorbing material is blended into the ink, and valuables are printed using the blended ink. Or using an infrared visualization device or an infrared detector equipped with a visible light spectrum cut filter.

An infrared absorbing material having an absorption peak near 975 nm, for example, ytterbium sulfate or ytterbium acetate is disclosed. By containing this material in the ink vehicle, a strong absorption peak is obtained in the vicinity of 975 nm, so that invisible non-information patterns such as detection marks and code patterns can be formed (see Patent Document 1).
JP-A-8-143853 (first page, FIGS. 1, 3)

Furthermore, an ink containing an infrared absorbing material that absorbs in the infrared region and does not absorb in the visible light region and has good absorption characteristics in the near infrared region, particularly in the wavelength region of 900 to 1000 nm, and An invisible pattern is disclosed (see Patent Document 2).
JP-A-9-104857 (first page, FIG. 1)

Further, in the printed matter provided with a desired design, at least a part of the design is printed using at least two types of inks having different near-infrared reflection absorption characteristics that cannot be easily identified visually. A printable matter that can be determined is disclosed (see Patent Document 3).
JP 63-144075 A (1st page, FIG. 1)

  However, Japanese Patent Laid-Open Nos. 8-143853, 9-104857, 63-144075, and known infrared light absorbing materials exhibit one absorption band or one reflection band. . For this reason, there existed a possibility that it might forge with the infrared-light absorption material in which one absorption zone or one reflection zone is similar. In addition, conventional infrared light absorbing materials are easily affected by the optical characteristics of the base material such as the base material, and no peak appears depending on the base material. I could not. For this reason, an ink composition that is less affected by the optical properties of the base such as a substrate, has a higher anti-counterfeit effect, and can be used for detection patterns such as barcodes, detection marks, and the like is required.

  In view of the above, the present invention aims to solve the above-mentioned problems, and is an ink composition that has little absorption in the visible wavelength region and contains a single or plural infrared light absorbing materials. An ink composition comprising an infrared light absorbing material having at least two absorption bands and at least one reflection band in the infrared light absorption spectrum of the infrared light absorbing material, The present invention proposes an ink composition that is hardly affected by the optical characteristics of the base, has a higher anti-counterfeit effect, and can be used for detection patterns such as barcodes, detection marks, and the like.

  The present invention is an ink composition containing a single or a plurality of infrared light absorbing materials, wherein the infrared light absorption spectrum of the infrared light absorbing material includes at least two absorption bands and at least one reflection band. An ink composition comprising an infrared light absorbing material having

  Moreover, this invention is an ink composition in which the said single or several infrared light absorption material contains at least 1 metal oxide.

  Moreover, this invention is an ink composition whose said metal oxide is nickel titanate, nickel tungstate, neodymium oxide, or samarium oxide.

  The present invention is the nickel titanate, having a first absorption band near 760 nm to 900 nm, a second absorption band near 1300 nm to 1500 nm, and a first reflection band 950 nm to 1120 nm. This is an ink composition in the vicinity.

  The present invention is the nickel tungstate, having a first absorption band in the vicinity of 760 nm to 900 nm, a second absorption band in the vicinity of 1400 nm to 1500 nm, and a first reflection band in the range of 980 nm to 1130 nm. This is an ink composition in the vicinity.

  Further, the present invention is the neodymium oxide, having a first absorption band in the vicinity of 760 nm to 765 nm, a second absorption band in the vicinity of 805 nm to 825 nm, and a first reflection band in the vicinity of 770 nm to 800 nm. And an ink composition having a second reflection band in the vicinity of 835 nm to 900 nm.

  Further, the present invention is the samarium oxide, having a first absorption band near 1090 nm, a second absorption band near 1250 nm, a third absorption band near 1400 nm to 1600 nm, The ink composition has a first reflection band around 1000 nm, a second reflection band around 1150 nm, and a third reflection band around 1300 nm.

  The present invention is an ink composition containing a single or a plurality of infrared light absorbing materials having low absorption in the visible wavelength region and excellent in ink properties, weather resistance, light resistance, chemical resistance, printability and the like. An ink composition comprising an infrared light absorbing material having at least two absorption bands and at least one reflection band in the infrared light absorption spectrum of the infrared light absorbing material, for example, a detection pattern When printing a detection mark, authenticity can be determined by at least two absorption bands, or at least two absorption bands and at least one reflection band. Excellent. Moreover, since it is hard to be influenced by the optical characteristics of the base such as the base material, the color of the base such as the base material is not limited. Furthermore, since there is little absorption in the visible wavelength region, when an ink composition is formed by adding an infrared light absorbing material to the vehicle, it can be used as a transparent ink composition that is nearly colorless, and confidential information such as Detection patterns such as codes, detection marks, and the like can be used as invisible information that is difficult to recognize with the naked eye. Therefore, the ink composition is most suitable for authenticity determination.

  The best mode for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the best mode for carrying out the invention described below, and includes various other embodiments within the scope of the technical idea described in the scope of claims.

  The present invention relates to an ink composition that has low absorption in the visible wavelength region and contains a single or a plurality of infrared light absorbing materials, and has at least two absorptions in the infrared light absorption spectrum of the infrared light absorbing material. An ink composition comprising an infrared light absorbing material having a band and at least one reflection band. The infrared light absorbing material preferably has at least two absorption bands and at least one reflection band in the near infrared region of about 760 nm to 3000 nm. The single or plural infrared light absorbing materials are composed of an inorganic compound or a mixture, and an inorganic composite oxide or an inorganic oxide is preferable. The single or plural infrared light absorbing materials referred to here will be described. The single infrared light absorbing material is a metal oxide such as nickel titanate, nickel tungstate, neodymium oxide, or samarium oxide, and the plurality of infrared light absorbing materials are nickel titanate or tungstic acid described above. Among metal oxides such as nickel, neodymium oxide, or samarium oxide, and two infrared light absorbing materials having one absorption band or one reflection band (for example, α-iron oxide, dysprosium oxide, etc.), two More than one type is selected. Two or more types of infrared light absorbing materials need to have absorption bands showing different absorption bands or reflection bands.

  Nickel titanate has a spectral reflectance of about 40% or less and a first absorption band in the vicinity of 760 nm to 900 nm, and further has a spectral reflectance of about 40% or less and a second absorption band in the vicinity of 1300 nm to 1500 nm. . More specifically, the spectral reflectance is about 40% or less and the first absorption band is in the vicinity of 760 nm to 900 nm, and the spectral reflectance is about 40% or less and the second absorption band is in the vicinity of 1300 nm to 1500 nm. The spectral reflectance is about 70% or more, and the first reflection band has a peak in the vicinity of a wavelength of 950 nm to 1120 nm and is in the vicinity. In this case,% is when the spectral reflectance of barium sulfate or aluminum oxide is 100% in the infrared region of 760 nm to 3000 nm.

  Nickel tungstate has a spectral reflectance of about 40% or less and a first absorption band near 760 nm to 900 nm, and a spectral reflectance of about 40% or less and a second absorption band around 1400 nm to 1500 nm. . More specifically, the spectral reflectance is about 40% or less and the first absorption band is in the vicinity of 760 nm to 900 nm, and the spectral reflectance is about 40% or less and the second absorption band is in the vicinity of 1400 nm to 1500 nm. The spectral reflectance is about 70% or more and the first reflection band is in the vicinity of 980 nm to 1130 nm. In this case,% is when the spectral reflectance of barium sulfate or aluminum oxide is 100% in the infrared region of 760 nm to 3000 nm.

  Neodymium oxide has a spectral reflectance of about 50% or less and a first absorption band in the vicinity of 760 nm to 765 nm, and further has a spectral reflectance of about 50% or less and a second absorption band in the vicinity of 805 nm to 825 nm. More specifically, the spectral reflectance is about 50% or less and the first absorption band is in the vicinity of 760 nm to 765 nm, and the spectral reflectance is about 50% or less and the second absorption band is in the vicinity of 805 nm to 825 nm. The spectral reflectance is about 80% or more and the first reflection band is in the vicinity of 770 nm to 800 nm, and the spectral reflectance is about 80% or more and the second reflection band is in the vicinity of 835 nm to 900 nm. In this case,% is when the spectral reflectance of barium sulfate or aluminum oxide is 100% in the infrared region of 760 nm to 3000 nm.

  Samarium oxide has a spectral reflectance of about 70% or less and a first absorption band near 1090 nm, a spectral reflectance of about 70% or less and a second absorption band near 1250 nm, and further has a spectral reflectance. Has a third absorption band in the vicinity of 1400 nm to 1600 nm. More specifically, the spectral reflectance is about 70% or less and the first absorption band is around 1090 nm, the spectral reflectance is about 70% or less and the second absorption band is around 1250 nm, and the spectral reflectance is Is about 70% or less, has a third absorption band near 1400 nm to 1600 nm, has a spectral reflectance of about 80% or more, has a first reflection band near 1000 nm, and has a spectral reflectance of about 80% or more. The second reflection band is in the vicinity of 1150 nm, the spectral reflectance is about 80% or more, and the third reflection band is in the vicinity of 1300 nm. In this case,% is when the spectral reflectance of barium sulfate or aluminum oxide is 100% in the infrared region of 760 nm to 3000 nm.

  The spectral reflectance of nickel titanate, nickel tungstate, neodymium oxide, or samarium oxide described above was blended with about 15 parts by weight of an infrared light absorbing material in 100 parts by weight of an ink composition having infrared light absorption characteristics. An ink composition having infrared light absorption characteristics was measured on a white paper on a white paper with an ink film thickness of about 12.5 μm. Therefore, the numerical values of the absorption band and the reflection band described above are not limited, and the visible light and the infrared region depend on the blending ratio of the infrared light absorbing material, the spectral reflectance of the base material, and the thickness of the ink film thickness. The spectral reflectances of are different.

  The absorption band or reflection band as used herein refers to a sharp peak curve due to absorption and reflection in the spectral reflectance curve, and infrared light is contained in 100 parts by weight of an ink composition having infrared light absorption characteristics. When an ink composition having about 15 parts by weight of an absorbent material and having infrared light absorption characteristics is coated on white paper with an ink film thickness of about 12.5 μm and the spectral reflectance of barium sulfate or aluminum oxide is 100%, The difference between the peak absorption band and the reflection band is about 20% or more, preferably about 40% or more. For example, about 100 parts by weight of an ink composition having infrared light absorption characteristics is blended with about 60 parts by weight of an infrared light absorption material. An ink composition having infrared light absorption characteristics is formed on black paper at an ink film thickness of about 10 μm. When the spectral reflectance of barium sulfate or aluminum oxide is 100%, the difference between the absorption band and the reflection band of each peak is about 10%. When the spectral reflectance of the substrate is low, the ink film thickness is thin, or the content of the infrared light absorbing material is small, the difference between the absorption band and the reflection band is small.

  Infrared light absorbing material consisting of metal oxides such as nickel titanate, nickel tungstate, neodymium oxide and samarium oxide having at least two absorption bands and at least one reflection band and one absorption band or one reflection It is possible to prepare an ink composition by mixing at least one infrared absorbing material made of α-iron oxide, dysprosium oxide or the like having a band into a vehicle or the like. It can also be contained in a coating composition used for coated paper or the like. Since the ink composition of the present invention is optimally used for authenticity determination, it is preferably applied to valuable items such as banknotes, passports, securities, cards, stamps, and product tags. When an infrared light absorbing material is used for the ink composition or the like, the particle diameter of the infrared light absorbing material is preferably about 0.001 μm to 10 μm.

  When an ink composition is formed, the vehicle must contain the infrared light absorbing material of the present invention. The vehicle is mainly composed of an oil component, a resin, a solvent that imparts appropriate viscosity and flow characteristics, and the like. . The vehicle containing the infrared light absorbing material is not particularly limited. For example, oils and fats such as linseed oil, olive oil, castor oil, sunflower oil, natural waxes such as whale wax, beeswax, lanolin, carnauba wax, canderia wax, montan wax, paraffin wax, microcrystalline wax, oxidized wax, Synthetic waxes such as ester wax, low molecular weight polyethylene, higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, flamenic acid and hebenic acid, higher alcohols such as stearyl alcohol and hebenyl alcohol, petrolatum, glycerin Soaps such as, hydrocarbons such as glucose, ethylene glucose and amylose, esters such as fatty acid esters, amides such as stearamide and oleinamide, polyamide resins, polyester resins Epoxy resin, polyurethane resin, acrylic resin, vinyl chloride resin, cellulose resin, polyvinyl resin, petroleum resin, ethylene-vinyl acetate copolymer resin, phenol resin, styrene resin, rosin modified resin, Resin such as terbin resin, elastomers such as natural rubber, styrene butadiene rubber, isoprene rubber, chloroprene rubber, tackifiers such as hydrogenated petroleum resin, silicone, liquid paraffin, fluororesin, etc. Can do. Furthermore, if necessary, pigments, dyes, surfactants, fillers, antioxidants, desiccants and the like may be added to the dispersion medium.

  In addition, functional pigments such as fluorescent pigments, pearl pigments, glass flakes, cholesteric liquid crystal pigments, and phosphorescent pigments may be contained in the ink containing the infrared light absorbing material of the present invention in the vehicle.

  The ink composition having infrared light absorption characteristics is prepared by mixing at least one infrared light absorption material described above in a vehicle with a composition having infrared light absorption characteristics. That is, as a material for absorbing the infrared region, an absorption peak can be arbitrarily set by combining a single material or a plurality of materials. It is also possible to disperse the nickel titanium oxide fired product as an infrared light absorber, either alone or using a nickel titanium oxide fired product, a metal complex, an infrared absorber, ITO, or the like.

  As an ink composition having infrared light absorption characteristics, a general ultraviolet curable ink, an oxidation polymerization type ink, a solvent type ink used for an offset ink, a gravure ink, a screen ink, an intaglio ink, etc. It is possible to use a normal drying method used for water-evaporating ink and the like, and it is not particularly limited. It is more preferable to use it for gravure ink, screen ink, and intaglio ink that can form an ink pile.

  The printing substrate can be used for paper, plastics, etc., which are usually used as a printing substrate, and is not particularly limited.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, the content of this invention is not limited to the range of these Examples.

(Example 1)
15 parts by weight of fine nickel titanate, 5 parts by weight of calcium carbonate as an extender pigment, 25.6 parts by weight of rosin-modified phenolic resin as a synthetic resin, 41.5 parts by weight of tung oil and linseed oil as vegetable oils, 12.8 parts of petroleum solvent An ink composition having infrared light absorption characteristics was prepared by mixing 0.1 part by weight of a desiccant as an additive and 0.1 part by weight of an auxiliary agent.

  Using the ink composition having the above infrared light absorption characteristics, a color developed product of Example 1 was produced using an applicator on white paper. FIG. 1 shows a spectral reflection graph of visible light and infrared region of the color-extended product of Example 1. As shown in FIG. 1, when the spectral reflectance of barium sulfate or aluminum oxide is 100%, the spectral reflectance is about 40% or less, and the first absorption band (1) shows a peak in the vicinity of 760 nm to 900 nm. When the spectral reflectance is about 40% or less, the second absorption band (2) has a peak near the wavelength of 1300 nm to 1500 nm, and when the spectral reflectance is about 70% or more, the first reflection band (4) has the wavelength of 950 nm to 1120 nm. A peak was shown in the vicinity.

  The color-extended product of Example 1 has absorption characteristics when irradiated with irradiation light or infrared laser light having passed through bandpass filters with center wavelengths of 800 nm and 1400 nm, and passed through a bandpass filter with a center wavelength of 1030 nm. When irradiated with irradiated light or infrared laser light, reflection characteristics were exhibited.

(Example 2)
15 parts by weight of fine nickel tungstate, 5 parts by weight of calcium carbonate as an extender pigment, 25.6 parts by weight of rosin-modified phenolic resin as a synthetic resin, 41.5 parts by weight of paulownia oil and linseed oil as vegetable oils, 12.8 parts of petroleum solvents An ink composition having infrared light absorption characteristics was prepared by mixing 0.1 part by weight of a desiccant as an additive and 0.1 part by weight of an auxiliary agent.

  Using the ink composition having the above infrared light absorption characteristics, a color developed product of Example 2 was produced using an applicator on white paper. FIG. 2 shows a spectral reflection graph in the visible light and infrared region of the color-extended product of Example 2. As shown in FIG. 2, when the spectral reflectance of barium sulfate or aluminum oxide is 100%, the spectral reflectance is about 40% or less, and the first absorption band (1) has a peak in the vicinity of 760 nm to 900 nm. When the spectral reflectance is about 40% or less, the second absorption band (2) has a peak near the wavelength of 1400 nm to 1500 nm, and when the spectral reflectance is about 70% or more, the first reflection band (4) has the wavelength of 980 nm to 1130 nm. A peak was shown in the vicinity.

  The color-exposed product of Example 2 has absorption characteristics when irradiated with irradiation light or infrared laser light having passed through bandpass filters with center wavelengths of 820 nm and 1450 nm, and passed through a bandpass filter with center wavelength of 1050 nm. When irradiated with irradiated light or infrared laser light, reflection characteristics were exhibited.

Example 3
15 parts by weight of neodymium oxide (made by Rare Metallic), 5 parts by weight of calcium carbonate as an extender pigment, 25.6 parts by weight of rosin-modified phenolic resin as a synthetic resin, 41.5 parts by weight of paulownia oil and linseed oil as vegetable oils, petroleum-based An ink composition having infrared light absorption characteristics was prepared by mixing 12.8 parts by weight of a solvent and 0.1 part by weight of a drying agent as an auxiliary agent.

  Using the ink composition having the infrared light absorption characteristics, a color developed product of Example 3 was prepared using an applicator on white paper. FIG. 3 shows a spectral reflection graph of visible light and infrared region of the color-extended product of Example 3. As shown in FIG. 3, when the spectral reflectance of barium sulfate or aluminum oxide is 100%, the spectral reflectance is about 50% or less, and the first absorption band (1) shows a peak in the vicinity of 760 nm to 765 nm. When the spectral reflectance is about 50% or less, the second absorption band (2) has a peak in the vicinity of 805 nm to 825 nm, and when the spectral reflectance is about 80% or more, the first reflection band (4) has a wavelength of about 770 nm to 800 nm. The spectral reflectance was about 80% or more, and the second reflection band (5) showed a peak near the wavelength of 835 nm to 900 nm.

  The color-extended product of Example 3 has absorption characteristics when irradiated with irradiation light or infrared laser light through bandpass filters with center wavelengths of 760 nm and 815 nm, and bandpass filters with center wavelengths of 780 nm and 850 nm. When irradiated with irradiation light or infrared laser light, reflection characteristics were exhibited.

Example 4
15 parts by weight of samarium oxide (manufactured by Kokusei Kagaku Kenkyusha), 5 parts by weight of calcium carbonate as an extender, 25.6 parts by weight of rosin-modified phenolic resin as a synthetic resin, and 41.5 parts by weight of paulownia oil and linseed oil as vegetable oils An ink composition having infrared light absorption characteristics was prepared by mixing 12.8 parts by weight of a petroleum solvent and 0.1 part by weight of a drying agent as an auxiliary agent.

  Using the ink composition having the above infrared light absorption characteristics, a color developed product of Example 4 was produced using an applicator on white paper. FIG. 4 shows a spectral reflection graph of visible light and infrared region of the color-extended product of Example 4. As shown in FIG. 4, when the spectral reflectance of barium sulfate or aluminum oxide is 100%, the spectral reflectance is about 70% or less, and the first absorption band (1) shows a peak in the vicinity of 1090 nm. Is about 70% or less, the second absorption band (2) has a peak in the vicinity of 1250 nm, the spectral reflectance is about 70% or less, and the third absorption band (3) has a peak in the vicinity of 1400 nm to 1600 nm. When the reflectance is about 80% or more, the first reflection band (4) shows a peak around 1000 nm, the spectral reflectance is about 80% or more, and the second reflection band (5) shows a peak around 1150 nm. The reflectance was about 80% or more, and the third reflection band (6) showed a peak in the vicinity of 1300 nm.

  The color-exposed product of Example 4 has absorption characteristics when irradiated with irradiation light or infrared laser light having passed through bandpass filters with center wavelengths of 1090 nm, 1250 nm, and 1500 nm, and has center wavelengths of 1000 nm, 1050 nm, and 1300 nm. When irradiated with irradiation light or infrared laser light through a band-pass filter, reflection characteristics were shown.

(Example 5)
10 parts by weight of neodymium oxide, 5 parts by weight of dysprosium oxide, 5 parts by weight of calcium carbonate as an extender, 25.6 parts by weight of rosin-modified phenolic resin as a synthetic resin, 41.5 parts by weight of paulownia oil and linseed oil as vegetable oils, petroleum-based An ink composition having infrared light absorption characteristics was prepared by mixing 12.8 parts by weight of a solvent and 0.1 part by weight of a drying agent as an auxiliary agent.

  Using the ink composition having the infrared light absorption characteristics, a color-extended product of Example 5 was produced using an applicator on white paper. FIG. 5 shows a spectral reflection graph in the visible light and infrared region of the color-extended product of Example 5. As shown in FIG. 5, when the spectral reflectance of barium sulfate or aluminum oxide is 100%, the spectral reflectance is about 70% or less, and the first absorption band (1) shows a peak near 760 nm. Is about 70% or less, the second absorption band (2) has a peak in the vicinity of 810 nm, and the spectral reflectance is about 70% or less, the third absorption band (3) has a peak in the vicinity of 1250 nm. Is about 90% or more, the first reflection band (4) shows a peak in the vicinity of 780 nm, the spectral reflectance is about 90% or more, and the second reflection band (5) shows a peak in the vicinity of 850 nm. Was about 90% or more, and the third reflection band (6) showed a peak near 1300 nm.

  The color-extended product of Example 5 has absorption characteristics when irradiated with irradiation light or infrared laser light through bandpass filters with center wavelengths of 760 nm, 810 nm, and 1250 nm, and has center wavelengths of 780 nm, 850 nm, and 1300 nm. In the case of irradiation with irradiation light or infrared laser light through a bandpass filter, reflection characteristics were shown.

Example 6
10 parts by weight of α-iron oxide, 5 parts by weight of dysprosium oxide, 5 parts by weight of calcium carbonate as an extender pigment, 25.6 parts by weight of rosin-modified phenol resin as a synthetic resin, 41.5 parts by weight of paulownia oil and linseed oil as vegetable oils, An ink composition having infrared light absorption characteristics was prepared by mixing 12.8 parts by weight of a petroleum solvent and 0.1 parts by weight of a drying agent as an auxiliary agent.

  Using the ink composition having the above infrared light absorption characteristics, a color developed product of Example 6 was produced using an applicator on white paper. FIG. 6 shows a spectral reflection graph in the visible light and infrared region of the color-extended product of Example 6. As shown in FIG. 6, when the spectral reflectance of barium sulfate or aluminum oxide is 100%, the spectral reflectance is about 40% or less, and the first absorption band (1) shows a peak in the vicinity of 780 nm to 940 nm. When the reflectance is about 60% or less, the second absorption band (2) shows a peak around 1250 nm, and when the spectral reflectance is about 80% or more, the first reflection band (4) shows a peak around 1050 nm to 1200 nm. When the spectral reflectance was about 80% or more, the second reflection band (5) showed a peak in the vicinity of 1280 nm to 1400 nm.

  The color-extended product of Example 6 has absorption characteristics when irradiated with irradiation light or infrared laser light through bandpass filters with center wavelengths of 850 nm and 1250 nm, and bandpass filters with center wavelengths of 1100 nm and 1350 nm. When irradiated with irradiation light or infrared laser light, reflection characteristics were exhibited.

  The ink composition having infrared light absorption characteristics used in the examples described in Examples 1 to 6 is 15 weight parts of at least one infrared light absorption material in 100 parts by weight of the ink composition having infrared light absorption characteristics. The ink composition having this infrared light absorption characteristic was prepared on a white paper with an ink film thickness of 12.5 μm, and a visible color and infrared spectral reflectance were measured. Therefore, the present invention is not limited to the blending ratio of the examples described in Examples 1 to 6, the spectral reflectance of the substrate, the thickness of the ink film, and the spectral reflectance. Depending on the blending ratio of the infrared light absorbing material, the spectral reflectance of the base material, and the thickness of the ink film thickness, the spectral reflectance in the visible light and the infrared region is different.

  The infrared light absorbing material of the present invention can be used for ink compositions, coating compositions such as coated paper, and the like, and in the past, authenticity was determined with one peak, but authenticity was determined with at least two peaks. Since discrimination can be performed, the ink composition is optimally used as an ink composition for authenticity determination and a coating composition for authenticity determination.

It is a figure which shows the spectrum of the spectral reflectance of the color development thing obtained in Example 1. FIG. It is a figure which shows the spectrum of the spectral reflectance of the color development thing obtained in Example 2. FIG. It is a figure which shows the spectrum of the spectral reflectance of the color development thing obtained in Example 3. FIG. It is a figure which shows the spectrum of the spectral reflectance of the color development thing obtained in Example 4. FIG. It is a figure which shows the spectrum of the spectral reflectance of the color development thing obtained in Example 5. FIG. It is a figure which shows the spectrum of the spectral reflectance of the color development thing obtained in Example 6. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st absorption zone | band 2 2nd absorption zone | band 3 3rd absorption zone | band 4 1st reflection zone 5 2nd reflection zone 6 3rd reflection zone

Claims (7)

A printed material for authenticity determination in which an ink composition containing a single or a plurality of infrared light absorbing materials is printed on a substrate ,
The infrared light absorbing material, the infrared absorption spectrum of the wavelength range of 760Nm～3000nm, at least two absorption bands, Ri name contains an infrared-absorbing material having at least one reflection band,
A printed matter for authenticity determination, wherein authenticity determination is performed based on a spectrum in an absorption band and a reflection band in a region where the ink composition is printed . The printed matter for authenticity determination according to claim 1, wherein the single or plural infrared light absorbing materials include at least one metal oxide. The printed matter for authenticity determination according to claim 2, wherein the metal oxide is nickel titanate, nickel tungstate, neodymium oxide or samarium oxide. 4. The nickel titanate, having a first absorption band near 760 nm to 900 nm, a second absorption band near 1300 nm to 1500 nm, and a first reflection band near 950 nm to 1120 nm. Printed material for authenticity determination . 4. The nickel tungstate, having a first absorption band in the vicinity of 760 nm to 900 nm, a second absorption band in the vicinity of 1400 nm to 1500 nm, and a first reflection band in the vicinity of 980 nm to 1130 nm. Printed material for authenticity determination . The neodymium oxide has a first absorption band near 760 nm to 765 nm, a second absorption band near 805 nm to 825 nm, a first reflection band near 770 nm to 800 nm, The printed matter for authenticity determination according to claim 3, which has a reflection band of approximately 835 nm to 900 nm. The samarium oxide has a first absorption band around 1090 nm, a second absorption band around 1250 nm, a third absorption band around 1400 nm to 1600 nm, and a first reflection band. The printed matter for authenticity determination according to claim 3 , wherein the printed matter has a vicinity of 1000 nm, a second reflection band near 1150 nm, and a third reflection band near 1300 nm.

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