JP2017145314A - Afterglow luminophor and authenticity discriminating method of printed matter using afterglow luminophor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an afterglow luminophor inhibiting imitation of light-emission characteristics due to mixture of phosphor and fluophor (without phosphorescence) as a plurality of phosphorescence peaks exits in wavelength region different from fluophor peaks.SOLUTION: There is provided an afterglow luminophor represented by the following chemical formula, where M is absence or Ca and α, β and γ are in following ranges, having a plurality of phosphorescence peaks in a wavelength region different from fluophor peaks. (Ba M)MgSiO;EuTbMn, 0.025≤α≤0.05, 0.05≤β≤0.2, 0.005≤γ≤0.05.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an afterglow illuminant suitable for authenticity determination, a printed matter using the same, and a method for determining authenticity using this characteristic.

  For printed matter that requires security, such as securities, forgery prevention and tampering and the identification of tampering and tampering identification are indispensable and it is essential to add anti-counterfeiting elements. Yes.

  As one of effective means for preventing the counterfeiting of securities and for determining the authenticity, it is proposed that a specific light emitter such as fluorescent light or phosphorescent light is applied to a part or the entire surface.

  Some securities, such as stamps, use light emission detection for the purpose of identification, identification, identification, etc.

  The authenticity determination method for security printed matter to which these luminescent ink compositions are applied includes the light emission of the light emitting element by irradiation of electromagnetic waves such as light containing energy capable of exciting the luminescent material, radiation, electric field application or chemical reaction. In a phenomenon and / or a phosphor, a method is generally used in which a sensor detects an afterglow phenomenon that is emitted while decaying after the application of excitation energy is stopped.

  Among the illuminants, the visible illuminant uses a simple tool such as black light as an excitation source to authenticate the luminescence with the human eye and mechanically performs the excitation and detection of the illuminant. And an authentication method using the afterglow time as a discrimination factor.

  In recent years, since phosphors, fluorescent inks, etc. are relatively easily available, features that differ from readily available phosphors for applications that require more advanced detection and discrimination, such as security prints. Therefore, it is necessary to use a luminescent material having the above luminescent characteristics. Examples of such illuminants having characteristic luminescence characteristics include illuminants whose emission color changes according to the excitation wavelength to be irradiated, such as electromagnetic waves, and illuminants having a distribution whose emission intensity varies greatly depending on the observation wavelength. As mentioned. In addition, a phosphor having phosphorescence as well as fluorescence and having characteristic characteristics in phosphorescence is more effective.

Examples of emitters having the above characteristics, the present applicant has the chemical formula _{(M k Ba a-x Eu} x) (a + k) O · (Mg b-y Mn y) bO · c (SiO 2) shows Where M is the alkaline earth metal Ca (calcium), Sr (strontium), Ba (barium), and the fluorescence emission color upon excitation light irradiation and the phosphorescence emission color after excitation light stop. , And an afterglow illuminant characterized in that the afterglow time after the excitation light is stopped is 2 ms to 5 s, a method for producing the afterglow illuminant, and a luminescent printed material (see Patent Document 1 and Patent Document 2). .

The present applicant has the _{formula: M x-y Mg 1-} z Si 2 O 5 + x + y; Ce y Mn z ( where M in the formula one or more selected from the group consisting of Ca, Sr and Ba, x is 1 ≦ x ≦ 3, y is in the range of 0.01 ≦ y ≦ 1.0, and z is in the range of 0.01 ≦ z ≦ 1.0.) The afterglow illuminant has an emission spectrum at the time of excitation light irradiation from 230 nm to 380 nm, a first peak wavelength in a wavelength range from 400 nm to 430 nm, and a wavelength range from 620 nm to 695 nm. There is a predetermined wavelength region having the second peak wavelength and no light emission between the first peak wavelength and the second peak wavelength, and the phosphorescence spectrum after stopping the excitation light is from 620 nm to 700 nm. Different from the second peak wavelength in the wavelength range An afterglow illuminant having an optical wavelength and having an afterglow time of 2 ms to 1 s after the afterglow of excitation light is stopped, its manufacturing method, and luminescent printed matter are presented (Patent Document) 3).

The present applicant has the formula: p (SrO) · q ( BaO) · r (MgO) · m (Al 2 O 3): Eu x, multifunction emitters and chemical formula represented by Mn _y: p ( _{BaO) · q (MgO) ·} r (Al 2 O 3): Eu x, be made by fixing the ink containing these and afterglow luminescent material represented by Mn _y and / or Nd _z to the substrate (See Patent Document 4 and Patent Document 5).

Japanese Patent No. 5610122 Patent 5799434 JP 2013-185022 A Japanese Patent No. 5186687 Japanese Patent No. 5186686

  The light emitters of Patent Document 1 to Patent Document 5 are different in fluorescence emission color and phosphorescence emission color after the excitation light is stopped, and have light emission characteristics with good machine readability and visual authentication. Since one of the peaks of the fluorescence spectrum is the same as the phosphorescence peak, there is a possibility that the same emission characteristics may be imitated by mixing the phosphor and the phosphor (no phosphorescence).

  The present invention has been made to solve the above-described problems, and has a plurality of phosphorescence peaks in a wavelength region different from the fluorescence peak, thereby providing emission characteristics by mixing phosphor and phosphor (no phosphorescence). An afterglow illuminator that prevents imitation of the light is provided.

The present invention is a phosphor represented by the following chemical formula, wherein M in the chemical formula does not exist or is Ca, and α, β, and γ are in the following ranges, and there are a plurality in a wavelength region different from the fluorescence peak. It is an afterglow luminescent material characterized by having a phosphorescent peak.
(Ba · M) _3-α-β Mg _1-γ Si ₂ O ₈ ; Eu _α Tb _β Mn _γ
0.025 ≦ α ≦ 0.05
0.05 ≦ β ≦ 0.2
0.005 ≦ γ ≦ 0.05

  The present invention relates to an afterglow luminescent material, wherein M is Ca, α = 0.05, 0.05 ≦ β ≦ 0.1, 0.009 ≦ γ <0.02. is there.

  The present invention has a fluorescence peak in the wavelength region 455 (nm) when irradiated with light having a wavelength centered on the wavelength region 254 nm or the wavelength region 365 nm, and the wavelength region 500 (nm) and the wavelength region 553 (nm). And an afterglow luminescent material characterized by having a phosphorescence peak in the wavelength region 624 (nm).

  The present invention is a luminescent ink comprising an afterglow luminescent material.

  The present invention is a true / false discrimination printed matter having a printed image formed of luminescent ink on at least a part of a substrate.

    The present invention is a true / false discrimination printed matter authenticity determination method, the step of irradiating the true / false discrimination printed matter with a first wavelength range, excitation light of a second wavelength range, and a first wavelength range The first detection wavelength range at the first detection time of each of the first phosphorescence characteristics after stopping the excitation light of the first and the second phosphorescence characteristics after stopping the excitation light of the second wavelength range A phosphorescence detection step for detecting each phosphorescence intensity from the first phosphorescence intensity to the fourth phosphorescence intensity, which is the value of the emission intensity in each detection wavelength area from the first to the fourth detection wavelength area, and both phosphorescences The calculation process for performing a numerical process for calculating the relative ratio of each phosphorescence intensity in each detection wavelength region in the first detection time in the characteristics, the relative ratio calculated in the calculation process, and a predetermined reference value are collated. Characterized in that it comprises a determination step of determining authenticity when it is within a predetermined reference value range. Is that authenticity discrimination method.

  In the phosphorescence detection step, the present invention further includes a first phosphorescence characteristic after stopping the excitation light in the first wavelength region and a second phosphorescence property after stopping the excitation light in the second wavelength region. Each phosphorescence intensity in each detection wavelength region at each second detection time of the light characteristics is detected, and in the calculation step, each detection wavelength of the first detection time and the second detection time in both the phosphorescence characteristics is detected. This is a true / false discrimination method characterized by performing numerical processing for calculating the relative ratio of each phosphorescence intensity in the region.

  The present invention is an authenticity determination method for authenticity determination printed matter, wherein the authenticity determination printed matter is irradiated with at least one excitation light in a first wavelength range and a second wavelength range, First detection time of at least one phosphorescence characteristic of the first phosphorescence characteristic after stopping the excitation light in the wavelength range or the second phosphorescence characteristic after stopping the excitation light in the second wavelength range The first phosphorescence intensity from the first phosphorescence intensity to the fourth phosphorescence intensity, which is the value of the emission intensity in each detection wavelength band from the first detection wavelength band to the fourth detection wavelength band in the second detection time. A phosphorescence detection step for detecting the light, an arithmetic step for performing a numerical process for calculating a relative ratio of the values of the respective phosphorescence intensities of the first detection time and the second detection time in at least one of the phosphorescence characteristics, and an arithmetic step The relative ratio calculated by the above and the reference value set in advance are collated. A authenticity discrimination method characterized by comprising a determination step of determining the authenticity if it is within the range of standard value.

  In the present invention, since a plurality of phosphorescent peaks appear in a wavelength region that cannot be predicted from the fluorescence spectrum, it is difficult to imitate a phosphorescent peak having the same characteristics as those of the present invention even when known materials are mixed.

Further, according to the present invention, in machine reading, the afterglow characteristic is detected by changing the excitation wavelength, and the afterglow characteristic detection time (timing) is set to plural (T ₁ , T ₂ ). It becomes possible to perform flexible fluorescent light detection, and the accuracy of authenticity determination is further improved.

The fluorescence spectrum and phosphorescence spectrum at the time of the excitation wavelength of 365 nm of one afterglow light-emitting body in one Example of this invention. The excitation spectrum of the afterglow light-emitting body in one Example of this invention. The figure which shows the time change of the emitted light intensity in specific light emission wavelength of the afterglow light-emitting body in one Example of this invention. The figure which shows the phosphorescence spectrum of the afterglow light-emitting body in one Example of this invention 2 ms after excitation light extinction, and 10 ms after. Process drawing which shows an example of the authenticity discrimination method. Process drawing which shows an example of the authenticity discrimination method. The fluorescence and phosphorescence spectrum of the afterglow light-emitting body in Example 1 of this invention. The X-ray-diffraction pattern of the afterglow light-emitting body in Example 1 of this invention. The fluorescence and phosphorescence spectrum of the afterglow light-emitting body in Example 2 of this invention. The X-ray-diffraction pattern of the afterglow light-emitting body in Example 2 of this invention. Fluorescence and phosphorescence spectra of authenticity printed materials. The figure which shows the time change of the emission spectrum of the authenticity discrimination | determination printed matter in Example 1 of this invention. The emission spectrum of the comparative printed matter in Comparative Example 1. The figure which shows the difference in the emission spectrum by the difference in the excitation wavelength of the comparative printed matter in the comparative example 1. FIG. The emission spectrum of the comparative printed material in Comparative Example 2.

  Although the form for implementing this invention is demonstrated, this invention is not limited to this, Other embodiments are also included if it is the range of the technical idea in description of a claim.

  The composition of the afterglow light-emitting body of the present invention and the process for producing it will be described.

(Composition of afterglow phosphor)
The present invention has a chemical formula: (Ba · M) _3-α-β Mg _1-γ Si ₂ O ₈ ; Eu _α Tb _β Mn _γ (wherein M is none or Ca, and α is 0.025 ≦ α ≦ 0.05, β is in the range of 0.05 ≦ β ≦ 0.2, and γ is in the range of 0.005 ≦ γ ≦ 0.05.) It is a luminous body.

  In the above chemical formula, Eu (europium), Tb (terbium), and Mn (manganese), which are activators, when α <0.025, the amount of activator is so small that the light emission becomes weak, and α> 0 In the case of .05, light emission is weak due to concentration quenching. Further, when β <0.05, the amount of activator is too small, and thus the light emission is weak. When β> 0.2, the light emission is weak due to concentration quenching. When γ> 0.05, the emission intensity in the 620 nm range increases and a peak begins to appear. In the case of γ <0.005, the phosphorescence intensity becomes small and the visual recognition becomes difficult.

(Raw-emitting phosphor material)
As an example of a raw material for Ca (calcium) and Ba (barium) represented by M, calcium carbonate (CaCO ₃ ), barium carbonate (BaCO ₃ ), barium oxide (BaO), and the like can be used.

As an example of the raw material of Mg (magnesium), SiO ₂ can be used as it is for nSiO ₂ such as magnesium carbonate (MgCO ₃ ) and magnesium oxide (MgO).

Eu (Europium), Tb (Terbium) and Mn (Manganese) which are activators include, as raw materials, Europium oxide (Eu ₂ O ₃ ), Terbium oxide (Tb ₂ O ₃ ), Manganese dioxide (MnO ₂ ), Manganese carbonate (MnCO ₃ ) or the like can be used.

  Next, the manufacturing process of the afterglow light-emitting body of the present invention will be described. The afterglow luminous body manufacturing process of the present invention includes a blending process for blending raw materials, a mixing process for mixing blended raw materials, and a firing process for firing a mixture dried after the mixing process in a reducing atmosphere. And a post-treatment step in which the mixture after the firing step is washed and then pulverized and classified.

(Mixing process)
In the blending step, each raw material of the afterglow phosphor is accurately weighed so as to obtain a target chemical composition, and sufficiently mixed so that the whole becomes uniform. In this case, wet mixing can be performed using a solvent or the like. Specifically, a base material containing chemical formulas Ba, Ca, Mg and SiO ₂ and raw materials for activators which are Eu, Tb and Mn are blended. In the production of the afterglow luminescent material of the present invention, the raw material of the metal serving as the luminescent center and the compound serving as the host material may be any material that can be converted into an oxide after high-temperature firing. Oxides, oxides, and the like can be used.

(Mixing process)
In the mixing step, the raw materials after the blending step are stirred and mixed with an alcohol such as ethanol or methanol having a relatively low boiling point. The reason why alcohols such as ethanol and methanol having a relatively low boiling point are used is to volatilize the solvent quickly after mixing.

(Baking process)
In the firing step, the mixture dried after the mixing step is fired in a reducing atmosphere at a firing temperature of 1200 ° C. to 1450 ° C. for 0.5 to 5 hours. Specifically, the raw material mixture is put in a heat-resistant container such as an alumina crucible, and is reduced in a reducing atmosphere such as nitrogen gas containing hydrogen gas or argon gas at a high temperature of 1250 ° C. to 1450 ° C. for 0.5 hour or more, preferably 1 hour. It can produce by the above baking. In particular, an afterglow luminescent material having high emission intensity of both fluorescence and phosphorescence is obtained when baked at a high temperature lower than the melting temperature of the raw material. In addition, when firing the afterglow phosphor, a compound containing fluorine or boron may be added for the purpose of controlling particle growth, which may be effective for improving the luminance of the present invention or preventing the production of a luminescent printed material. It can be used within the range not to be. In this case, the firing temperature can be adjusted according to the characteristics of the particle growth agent.

  In addition, before baking in a reducing atmosphere, a step of baking at 600 ° C. to 1200 ° C. for 0.5 hours or more in a natural oxidation atmosphere may be included. Can be produced.

(Post-processing process)
In the post-treatment step, the produced afterglow phosphor is washed, pulverized, and classified by a known method according to the use. When applying to a base material by printing as printing ink, it is desirable that the afterglow illuminant has an average particle diameter of 20 μm or less. However, since the pulverization of the inorganic luminescent material decreases the luminescence intensity, it is necessary to adjust the particle size according to the printing method so that it does not become too fine.

  FIG. 1 is a diagram showing a fluorescence spectrum at an excitation wavelength of 365 nm and a phosphorescence spectrum after 2 ms of extinction of excitation light at excitation wavelengths of 365 nm and 254 nm of an afterglow luminescent material in one example of the present invention. As shown in FIG. 1, the afterglow luminescent material of the present invention shows a broad spectrum shape of a single peak having a peak at 458 nm in the fluorescence spectrum. The phosphorescence spectrum at an excitation wavelength of 365 nm shows a spectrum shape having three peaks having peaks at 500 nm, 552 nm, and 622 nm, and the phosphorescence spectrum at an excitation wavelength of 254 nm has peaks at 501 nm, 553 nm, and 624 nm. A spectral shape having three peaks with In the phosphorescence spectrum, the ratio of the intensity of each peak wavelength differs depending on the excitation wavelength, the peak intensity at 622 nm is relatively high at the excitation wavelength 365 nm, and the peak at 624 nm is relatively high at the excitation wavelength 254 nm. The strength is low.

  The fluorescence peak in the present invention means the maximum value of emission intensity in the fluorescence spectrum and its emission wavelength range, and the phosphorescence peak means that the emission intensity decreases from an increase in the phosphorescence spectrum as seen from the low wavelength region. It is an inflection point that changes to.

  FIG. 2 is a diagram showing an excitation spectrum of an afterglow luminescent material in one example of the present invention. As shown in FIG. 2, the fluorescence has a shape in which the intensity distribution in the ultraviolet light region is close to a trapezoid at an emission wavelength of 458 nm. Phosphorescence showed a peak at about 250 nm at emission wavelengths of 499 nm and 552 nm, and showed a flat spectrum shape with low intensity in a wavelength region of about 280 nm or more. When the emission wavelength was 624 nm, the same tendency as the fluorescence excitation spectrum was observed. In FIG. 1, it can be explained from the excitation spectrum of FIG. 2 that the intensity ratio of each peak wavelength is different between excitation wavelengths 365 nm and 254 nm.

  FIG. 3 shows the time variation of the emission intensity of the afterglow luminescent material in one example of the present invention at a specific emission wavelength. The time on the x-axis in the graph of FIG. 3 shows the passage of time when the excitation light lighting time is 0 ms. The light is turned off at 400 ms after the light source is turned on, but after the light is turned off, the afterglow of light emission wavelength 541 nm is fast and the decay is slow at 625 nm. Although not shown, the light emission wavelength of 488 nm showed the same tendency as that of 541 nm. Although the emission peak wavelength is different from that in FIG. 1, it is a known fact that the peak wavelength is different when the measuring instrument and measurement conditions are different.

  Since the decay time of afterglow varies depending on the emission wavelength, the phosphorescence spectrum shape varies depending on the measurement time (timing), and the phosphorescence spectra after 2 ms and 10 ms of excitation light extinction are shown in FIG. At excitation wavelengths of 254 nm and 365 nm, a spectrum shape having three peaks was shown after 2 ms of extinguishing of the excitation light, whereas a spectrum shape of a single peak having only the longest wavelength peak of 625 nm was shown after 10 ms.

  The afterglow phosphor in one embodiment of the present invention has a slow decay of afterglow at 625 nm, and this characteristic contributes to visual authentication of afterglow. The requirement for visual authentication of afterglow is that the afterglow time is longer than a certain length, but if the afterglow time is less than a second, there is also a requirement that there is a hue difference between the fluorescent color and the afterglow color. The higher the hue difference, the higher the authenticity. The condition of the afterglow time for visual authentication is 10 ms or more (see Patent Document 5610121 for the definition of the afterglow time). However, since 625 nm is 10 ms or more, visual authentication is possible, and 500 nm and 541 nm are less than 10 ms. I can't authenticate. Therefore, the afterglow color is observed red by visual observation.

(Luminescent ink composition)
The production of the luminescent ink composition will be described. Depending on the method for applying the produced afterglow luminescent material, the viscosity and the like are adjusted by mixing well with a binder, an auxiliary agent, and the like so as to have characteristics suitable for application, and are converted into an ink or a paste. Although it depends on the application method, the blending ratio of the afterglow phosphor may be about 1 to 60% by weight. From the viewpoint of light emission intensity and economy, it is more desirable that the content be 10 to 40% by weight.

  The binder used in the luminescent ink composition 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 and low molecular weight polyethylene, higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, furomenic acid and hebenic acid, higher alcohols such as stearyl alcohol and hebenyl alcohol, glucose and ethylene Hydrocarbons such as glucose and amylose, esters such as fatty acid esters, amides such as stearamide and oleinamide, polyamide resins, polyester resins, epoxy resins, polyurethane resins, acrylic resins , Vinyl chloride resin, cellulose resin, polyvinyl resin, petroleum resin, ethylene / vinyl acetate copolymer resin, phenol resin, styrene resin, rosin modified resin, terbin resin, natural rubber, styrene Elastomers such as butadiene rubber, isoprene rubber, and chloroprene rubber, UV curable resins composed of oligomers and monomers of acrylate, methacrylate, tackifiers such as hydrogenated petroleum resins, silicone, liquid paraffin, and fluororesin are contained alone or contained. A binder made of a product can be used.

  The luminescent ink composition may be made into an ink or paste by mixing other color materials or functional materials within a range that does not interfere with light emission, or may be applied in a layered manner on a base previously provided on a substrate. Good.

  As a method of applying the luminescent ink composition to the substrate by printing, coating, etc., generally known methods such as intaglio, letterpress, offset, screen, gravure, flexographic printing or ink jet printing, coating, etc. can be used. Moreover, you may provide by the combination of these printing systems. A product obtained by printing or coating the luminescent ink composition or the coating composition thus prepared on a substrate is referred to as a true / false discrimination printed material.

  For example, since the luminescent ink composition of the present invention emits visible light when irradiated with specific ultraviolet rays, the first image line and the second image line are arranged at different angles using the ink composition. This is used for printed matter (for example, Japanese Patent No. 4374446) that forms a background portion and a latent image portion, and the latent image can be visually recognized by tilting the printed matter. Irradiation makes it possible to visually determine the presence or absence of visible light emission and afterglow, or to make good discrimination by machine reading, so that a printed matter with excellent authenticity discrimination can be produced.

  Further, when a bright pigment is blended in the luminescent ink composition of the present invention, the first image line and the second image line are arranged at different angles using the ink, and the background portion and the latent image portion. Is used for printed matter (for example, WO2003 / 013871) where a latent image of an arbitrary gradation can be visually recognized by tilting the printed matter, and the forgery prevention effect by the latent image and specific ultraviolet rays are irradiated. As a result, the visual discrimination of the presence or absence of visible light emission and phosphorescence or the discrimination by machine reading becomes good, so that a printed matter excellent in authenticity discrimination can be produced.

(Authentication method)
The visual discrimination method for authenticity determination printed matter of the present invention will be described. A hand-held ultraviolet lamp such as a black light is irradiated on the authenticity printed matter, and the fluorescence emission is first observed visually. In one embodiment of the present invention, the fluorescent color is observed as bluish white. Next, the ultraviolet lamp is turned off instantaneously or the printed matter for authenticity determination is quickly scanned in the lighting state. When the ultraviolet lamp is turned off instantaneously, phosphorescence having a color different from the fluorescent color, such as an afterimage, is observed instantaneously. When the authenticity determination printed material is scanned quickly with the ultraviolet lamp turned on, phosphorescence of a color different from the fluorescent color is instantaneously observed after the lamp has passed. In one embodiment of the present invention, the phosphorescent color is red.

  The machine discrimination method for authenticity determination printed matter of the present invention will be described. As a general authenticity determination method using a machine, there is light emission during irradiation and detection of presence / absence of afterglow after irradiation by irradiating the authenticity determination printed matter with ultraviolet light. The accuracy of discrimination is improved by detecting an output within a predetermined threshold range according to the emission intensity of the authenticity discrimination printed matter. For detecting afterglow, an afterglow detection device or the like can be used. As an example of the presence / absence detection of afterglow, it is possible to make a determination using a stamp detection device as disclosed in Japanese Patent Application Laid-Open No. 8-3785.

  As a method of using the afterglow illuminant of the present invention, for example, a method of using it as a fluorescent mark in an automatic processing system for a postage stamp is conceivable. Of course, it can be distinguished from the fluorescent brightening agent by reading the afterglow, but since the hue is red, the hue is greatly different from that of blue, which is the emission color of the brightening agent, so that the separation is easy. Furthermore, since the afterglow illuminant of the present invention is longer than the afterglow lifetime of the afterglow illuminator normally used for machine detection, it is later than the detection timing (5 to 30 ms) at which normal detection is performed. It is possible to detect at the timing, and even by delaying the detection timing, it can be differentiated from the existing light emitting mark and used for authenticity determination.

Although it is a more accurate machine discrimination method, for example, an apparatus and method proposed in Japanese Patent Application Laid-Open No. 2006-266810 may be used as a method capable of performing machine discrimination with high accuracy in a short time with an inexpensive device. it can. The discrimination method by this apparatus irradiates excitation light of one wavelength region, and irradiates excitation light with different wavelength regions (λ ₁ , λ ₂ , λ _3, and λ ₄ ) by four light receiving units (T ₀ ). Then, the light is received several tens of ms after stopping the irradiation of the excitation light (T ₁ ), and T ₀ λ ₁ , T ₀ λ ₂ , T ₀ λ ₃ , T ₀ λ ₄ , T ₁ λ ₁ , T ₁ λ ₂ , T ₁ A method can be used in which the light emission intensity of λ ₃ and T ₁ λ ₄ is compared with a light emission intensity value designated in advance.

As another example of a more accurate machine discrimination method, it can be discriminated by, for example, an apparatus and method proposed in Japanese Patent Laid-Open No. 2006-275578. The discrimination method by this apparatus irradiates excitation light in one wavelength region, receives light during excitation light irradiation (T ₀ ) and after several ms (T ₁ ) after stopping the excitation light irradiation, and obtains a spectrum S _{0 of} T _0. in which to determine confirmed the spectral shape of the spectrum S ₁ of T _1. In addition, the spectrum is measured according to the elapsed time (T ₀₁ , T ₀₂ , T ₀₃ ,...) After stopping the excitation light irradiation, and the output intensity changes at the peak wavelengths λ ₁ , λ ₂ , λ ₃ and λ ₄ are followed. Good. Note that the spectral distribution of the obtained spectrum can be further calculated by a computer and compared as color values (x, y, Y or L ^* , a ^* , b ^* ) for discrimination.

An authenticity determination method that effectively utilizes the characteristics of the light emitter of the present invention will be described. In order to explain the authenticity determination method, the definition of symbols will be described with reference to FIGS. The elapsed time after the excitation light turns off, and T ₂ a first detection time T ₁ and the second detection time. The phosphorescent properties at the wavelength EX ₁ of the excitation light and the first phosphorescent properties P _1, the phosphorescent properties at the wavelength EX ₂ of the excitation light and the second phosphorescent properties P _2. Let the detection wavelength range be λ ₁ , λ ₂ , λ ₃ , and λ ₄ from the short wavelength side. lambda ₁ is the emission peak wavelength range of the fluorescence spectrum, the detection order that there is no phosphorescence peak in the same wavelength range as the fluorescent becomes authenticity discrimination element. λ ₂ , λ ₃ , and λ ₄ are phosphorescence peak wavelength regions.

The emission intensity of λ ₁ at the first phosphorescence characteristic P ₁ and the first detection time T ₁ is I ₁₁ , the emission intensity of λ ₂ is I ₁₂ , the emission intensity of λ ₃ is I ₁₃ , and the emission intensity is λ ₄ . strength and _{I 14.} The light emission intensity of λ ₁ at the first phosphorescence characteristic P ₁ and the second detection time T ₂ is I ′ ₁₁ , the light emission intensity of λ ₂ is I ′ ₁₂ , the light emission intensity of λ ₃ is I ′ ₁₃ , λ the emission intensity of ₄ and I _'14. The emission intensity of λ ₁ at the second phosphorescence characteristic P ₂ and the first detection time T ₁ is I ₂₁ , the emission intensity of λ ₂ is I ₂₂ , the emission intensity of λ ₃ is I ₂₃ , and the emission intensity is λ ₄ . strength and _{I 24.} The emission intensity of λ ₁ at the second phosphorescence characteristic P ₂ and the second detection time T ₂ is I ′ ₂₁ , the emission intensity of λ ₂ is I ′ ₂₂ , the emission intensity of λ ₃ is I ′ ₂₃ , λ the emission intensity of ₄ and I _'24.

5 and 6 are examples of the authenticity determination method for authenticity determination printed matter according to the present invention. An irradiation step (S1) for irradiating the printed image of the authenticity discrimination printed matter with excitation light, and a phosphorescence detection step for detecting phosphorescence after stopping the excitation light in the detection wavelength ranges λ ₁ , λ ₂ , λ ₃ , λ ₄ ( S2) and the detection value detected in the phosphorescence detection step (S2) are used as a calculation step (S3) for calculation, and a determination step (S4) for determining authenticity from the calculation step result.

Figure 5 shows in a first detection time T _1, a determination example by the emission intensity ratio of the detection wavelength ranges of the first phosphorescent characteristics P ₁ and the second phosphorescent properties P _2. In the irradiation step (S1), and irradiated with an excitation light of the excitation wavelength EX _1, in phosphorescence detection step (S2), the first phosphorescent properties _{P 1} in the first detection time _{T 1,} the wavelength region lambda _1, The phosphorescence at λ ₂ , λ ₃ , and λ ₄ is detected. Next, in the irradiation step (S1 ′), the excitation light of the excitation wavelength EX ₂ is irradiated, and in the phosphorescence detection step (S2 ′), the second phosphorescence characteristic P ₂ at the first detection time T ₁ is Phosphorescence in the wavelength bands λ ₁ , λ ₂ , λ ₃ , λ ₄ is detected. In addition, the detection value detected by the phosphorescence detection process (S2 and S2 ') is calculated by relative ratio calculation in the calculation process (S3). In the determination step (S4), the authenticity determination of the authenticity determination printed matter is performed based on the calculation result in the calculation step (S3).

FIG. 6 shows a discrimination example based on the emission intensity ratio in each detection wavelength region of the first detection time T ₁ and the second detection time T ₂ in the first phosphorescence characteristic P ₁ . In the irradiation step (S1), excitation wavelength EX ₁ and / or excitation wavelength EX ₂ of irradiated with excitation light, phosphorescence detection step in (S2), the first phosphorescent properties _{P 1} in the first detection time _{T 1} And / or phosphorescence in the wavelength regions λ ₁ , λ ₂ , λ ₃ , λ ₄ of the second phosphorescence characteristic P ₂ is detected, and the second detection time T ₂ is detected in the phosphorescence detection step (S2 ′). The phosphorescence in the wavelength range λ ₁ , λ ₂ , λ ₃ , λ ₄ of the first phosphorescence characteristic P ₁ and / or the second phosphorescence characteristic P ₂ is detected. The detection value detected in the phosphorescence detection step (S2 and S2 ′) is calculated in the calculation step (S3). Based on the calculation result in the calculation step (S3), the authenticity determination of the authenticity determination printed matter is performed in the determination step (S4). In the present embodiment, only one excitation wavelength is used. However, both excitation wavelengths may be used for more accurate inspection.

Examples of excitation light sources in the irradiation process (S1 and S1 ′) include LED light sources, low-pressure light source lamps, xenon lamps, deuterium light sources, etc. Limits the irradiation wavelength with a band-pass filter, a high-pass filter, a low-pass filter, or the like. As the excitation wavelengths EX ₁ and EX ₂ , any wavelength range of 230 nm to 420 nm can be selected, but either EX ₁ or EX ₂ is from the wavelength range of 230 nm to 255 nm, and the other is from the wavelength range of 255 nm to 420 nm. Select a specific wavelength. As an example, EX ₁ is 254 nm and EX ₂ is 365 nm.

Examples of the detector in the phosphorescence detection step (S2 and S2 ′) include a silicon photodiode detector and a photomultiplier. Even if a sharp-cut filter or a band-pass filter is attached to detect the emission (phosphorescence) after stopping the excitation light irradiation in the detection wavelength ranges λ ₁ , λ ₂ , λ ₃ and λ ₄ , each detector can detect it. Alternatively, a linear sensor or an image sensor having a plurality of detectors may be used. An amplifier may be used in combination to improve sensitivity. Moreover, you may acquire spectral characteristics using a spectroscope together.

  In the phosphorescence detection step (S2 and S2 '), the emission characteristic (phosphorescence) after the excitation light is stopped is acquired by controlling the time factor. The phosphorescence acquisition timing is controlled by intermittently irradiating the excitation light while detecting the phosphorescence when the light is extinguished, or by irradiating the excitation light continuously and determining the authenticity according to the time timing you want to acquire. There is a method of detecting by moving the printed material from the position of the excitation light source.

In the calculation step (S3), data necessary for determination is selected from the detection values acquired in the phosphorescence detection step (S2 and S2 ′), and calculation based on the determination criterion is performed. For example, the emission peak values of EX ₁ and EX ₂ or T ₁ and T _{2 in} the detection wavelength ranges λ ₁ , λ ₂ , λ _3, and λ ₄ are picked up, and the relative ratios are calculated. When calculating from the acquired spectral characteristics, the wavelength ranges λ ₁ , λ ₂ , λ ₃ and λ ₄ are selected, and the emission peak values of EX ₁ and EX ₂ or T ₁ and T ₂ in these wavelength ranges are picked up. Calculate the relative ratio.

As for the relative ratio calculation, in the discrimination example based on the emission intensity ratio of each detection wavelength region of the first phosphorescence characteristic P ₁ and the second phosphorescence characteristic P ₂ at the first detection time T ₁ shown in FIG. Is the ratio of the emission intensity of P ₁ and P ₂ for each wavelength range of λ ₁ , λ ₂ , λ ₃ , λ ₄ (I ₁₁ / I ₂₁ , I ₁₂ / I ₂₂ , I ₁₃ / I ₂₃ , I ₁₄ / I ₂₄ ) is calculated.

Regarding the relative ratio calculation, in the discrimination example based on the emission intensity ratio in each detection wavelength region of the first detection time T ₁ and the second detection time T ₂ in the first phosphorescence characteristic P ₁ shown in FIG. , Λ ₁ , λ ₂ , λ ₃ , λ ₄ for each wavelength region, the ratio of the emission intensity at T ₁ and T ₂ (I ₁₁ / I ′ ₁₁ , I ₁₂ / I ′ ₁₂ , I ₁₃ / I ′ ₁₃ , I ₁₄ / I ′ ₁₄ ). Alternatively, in the discrimination example based on the emission intensity ratio in each detection wavelength region of the first detection time T ₁ and the second detection time T ₂ in the second phosphorescence characteristic P ₂ , λ ₁ , λ ₂ , λ ₃ , The ratio of the emission intensity at T ₁ and T ₂ (I ₂₁ / I ′ ₂₁ , I ₂₂ / I ′ ₂₂ , I ₂₃ / I ′ ₂₃ , I ₂₄ / I ′ ₂₄ ) is calculated for each wavelength region of λ _4. .

  Depending on the determination method, the detection value used for the determination may be regarded as 0 for a detection value less than a certain value, or may be processed outside the determination criterion so that an output due to noise or a very weak output is not used for the determination. Good. Further, when the output waveform in the selected wavelength range is unstable, a process of calculating an average value within a predetermined wavelength range may be performed.

  In the determination step (S4), the relative ratio calculated in the calculation step is compared with a reference value of a predetermined relative ratio, and is determined to be authentic when it is within a predetermined reference value range.

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited to these examples. First, a method for manufacturing an afterglow light emitter will be described.

The raw materials having the composition shown in Table 1 were accurately weighed, thoroughly mixed in an ethanol solvent, and dried. The sufficiently mixed powder was put in an alumina container and fired at 1400 ° C. for 2 hours in a reducing atmosphere (N ₂ + H ₂ (4%)). The fired product obtained by this reaction is referred to as afterglow phosphor 1- (1). The afterglow phosphor 1- (1) is represented by a molar ratio of 2.65Ba · 0.2Ca · 0.983Mg · Si ₂ O ₈ : 0.05Eu · 0.1Tb · 0.017Mn.

  The afterglow phosphor 1- (1) was coarsely pulverized in an agate mortar, and the emission characteristics were measured with a spectrofluorimeter (F-4500, manufactured by Hitachi High-Technologies Corporation). FIG. 7 shows fluorescence and phosphorescence spectra when excited with ultraviolet light. Fluorescence showed a single emission peak at 456 nm. Phosphorescence showed emission peaks at 500 nm, 552 nm, and 622 nm. Visually, the fluorescent color was observed in dark blue and the phosphorescent color was observed in red.

  The hue of the fluorescent color was x = 0.225 and y = 0.365 as a result of measurement with a UV352 nm light source and Minolta color difference meter CS-100.

  Afterglow measurement of the afterglow luminous body 1- (1) was performed. The afterglow time (lifetime) was 81.4 ms as a result of performing afterglow measurement using an excitation light source as an LED light source having a central wavelength of 365 nm and an irradiation time of 400 ms.

The X-ray diffraction pattern of the afterglow phosphor 1- (1) is shown in FIG. From the measurement results, it was found that the crystal structure was mainly composed of Ba ₃ MgSi ₂ O ₈ .

Similarly, the chemical _{formula: (Ba · M) 3-} α-β Mg 1-γ Si 2 O 8; Eu α Tb β Mn except that the values were changed as shown in Table 2 in _gamma is afterglow luminescent material Afterglow light emitters 1- (2) to 1- (10) were produced under the same conditions as 1- (1).

The raw materials having the composition shown in Table 3 were accurately weighed, thoroughly mixed in an ethanol solvent, and dried. The sufficiently mixed powder was put in an alumina container and fired at 1350 ° C. for 3 hours in a reducing atmosphere (N ₂ + H ₂ (4%)). The fired product obtained by this reaction is referred to as an afterglow phosphor 2- (1). The afterglow phosphor 2- (1) is represented by a molar ratio of 2.9Ba0.995Mg · Si ₂ O ₈ : 0.05Eu · 0.05Tb · 0.005Mn.

  Afterglow luminous body 2- (1) was coarsely pulverized in an agate mortar, and the luminescence characteristics were measured with a spectrofluorimeter (F-4500, manufactured by Hitachi High-Technologies Corporation). FIG. 9 shows fluorescence and phosphorescence spectra. Fluorescence showed a single emission peak at 446 nm. In the phosphorescence spectrum at an excitation wavelength of 254 nm, emission peaks were shown at 500 nm, 552 nm, and 622 nm. Visually, the fluorescent color was observed in dark blue and the phosphorescent color was observed in red. In the phosphorescence spectrum at an excitation wavelength of 365 nm, emission peaks were shown at 502 nm, 552 nm, and 625 nm. Visually, the fluorescent color was observed in dark blue and the phosphorescent color was observed in red.

  The hue of the fluorescent color was x = 0.183 and y = 0.181 as a result of measurement with a UV352 nm light source and Minolta color difference meter CS-100.

  Afterglow measurement of the afterglow luminous body 2- (1) was performed. The afterglow time (lifetime) was 90.0 ms as a result of performing afterglow measurement using an excitation light source as an LED light source having a central wavelength of 365 nm and an irradiation time of 400 ms.

The X-ray diffraction pattern of the afterglow luminescent material 2- (1) is shown in FIG. From the measurement results, it was found that it was composed of a mixed phase of a plurality of crystal phases containing Ba ₃ MgSi ₂ O ₈ .

Similarly, afterglow emission except that each value in the chemical formula: (Ba · M) _3-α-β Mg _1-γ Si ₂ O ₈ ; Eu _α Tb _β Mn _γ was changed as shown in Table 4. Afterglow light emitters 2- (2) to 2- (3) were produced under the same conditions as for the body 2- (1).

  Next, the adjustment method of the luminescent ink composition using the afterglow luminescent material of the present invention and the authenticity printed matter preparation method will be described.

(Luminescent ink composition 1)
Using the afterglow luminescent material 1- (1) of Example 1, a luminescent screen ink composition 1 was prepared by a planetary ball mill (manufactured by Fritsch) with the composition shown in Table 5.

(Luminescent ink composition 2)
Using the afterglow luminescent material 1- (1) of Example 1, a luminescent flexo ink composition 2 was prepared with a planetary ball mill (manufactured by Fritsch) with the formulation shown in Table 6.

(Production of authenticity discrimination printed matter 1)
Using screen printing method, using 200-mesh printing plate, applying luminous screen composition 1 to high-quality paper that is not whitened with solid and wrinkle patterns, and then drying the ink to produce authenticity printed matter 1 did. FIG. 11 shows an emission spectrum obtained by measuring the portion to which the luminescent screen composition 1 is applied with a spectrofluorometer. The fluorescence showed a spectral shape with a single emission peak at 456 nm, and the phosphorescence spectrum at an excitation wavelength of 365 nm showed a spectral shape with three peaks at 500 nm, 552 nm, and 622 nm. Since a UV varnish is used, the emission intensity at 254 nm excitation is extremely low, but the spectral shape is the same as in the case of powder.

(Preparation of authenticity printed matter 2)
After applying the flexographic composition 2 to high-quality paper that has not been fluorescently whitened with solid and wrinkle patterns at anilox roller 140 lines / inch using the flexographic printing method, the ink is dried to produce a true / false discrimination printed matter 2 did. The emission spectrum obtained by measuring the portion to which the light-emitting flexo composition 2 was applied with a spectrofluorometer was the same as that shown in FIG. The fluorescence showed a spectral shape with a single emission peak at 456 nm, and the phosphorescence spectrum at an excitation wavelength of 365 nm showed a spectral shape with three peaks at 500 nm, 552 nm, and 622 nm. Since a UV varnish is used, the emission intensity at 254 nm excitation is extremely low, but the spectral shape is the same as in the case of powder.

  Next, the authenticity determination method of the authenticity determination printed matter using the afterglow illuminant of the present invention will be described.

(Visual discrimination of authenticity printed matter)
The true / false discrimination printed matter 1 and the authenticity discrimination printed matter 2 were irradiated with 365 nm ultraviolet light with a handy type ultraviolet lamp, and bluish white fluorescence was observed. An ultraviolet lamp irradiating with 365 nm ultraviolet light was moved so as to scan on the printed matter, and it was visually confirmed that the luminescent ink composition application portion changed to red instantaneously.

(Machine identification of printed matter for authenticity discrimination)
(Irradiation process / phosphorescence detection process)
Irradiation of the authenticity printed matter 1 with excitation light having a wavelength of 254 nm (excitation wavelength EX ₁ ), and detection wavelength range λ ₁ = 456 nm (center wavelength) 2 ms after the excitation light stops (first detection time T ₁ ), Phosphorescence of λ ₂ = 500 nm (center wavelength), λ ₃ = 552 nm (center wavelength), and λ ₄ = 622 nm (center wavelength) was detected by a silicon photodiode detector. Next, irradiation with excitation light having a wavelength of 365 nm (excitation wavelength EX ₂ ) is performed, and after 2 ms (first detection time T ₁ ) after the excitation light is stopped, a detection wavelength region λ ₁ = 456 nm (center wavelength), λ ₂ = Phosphorescence of 500 nm (center wavelength), λ ₃ = 552 nm (center wavelength), and λ ₄ = 622 nm (center wavelength) was detected with a silicon photodiode detector.

(Calculation process)
At excitation wavelength EX ₁ and 254 nm, the phosphorescence intensity at λ ₁ is I ₁₁ , the phosphorescence intensity at λ ₂ is I ₁₂ , the phosphorescence intensity at λ ₃ is I ₁₃ , and the phosphorescence intensity at λ ₄ is I ₁₄ . I ₁₁ = 0 mV (estimated value), I ₁₂ = 19.2 mV, I ₁₃ = 57.9 mV, I ₁₄ = 157.5 mV. At an excitation wavelength EX ₂ of 365 nm, I ₂₁ = 0 mV, I ₂₂ = 112 mV, I ₂₃ = 340 mV, and I ₂₄ = 5100 mV. When the determination reference value is set as shown in Table 7 and the error allowed in the determination is ± 10%, the true / false determination result is “true” as shown in Table 7.

(Example of measurement timing differences)
(Irradiation process / phosphorescence detection process)
The authenticity printed matter 1 was subjected to authenticity determination using a spectrophotometric device PMA-11 multichannel detector. The excitation light source was a 375 nm LED light source, and the spectroscopic measurement was performed in 1 ms steps with a pulse frequency of 1 Hz and an excitation light irradiation time of 400 ms. FIG. 12 shows fluorescence spectra at 1 ms and 76 ms, and phosphorescence spectra at 401 ms and 405 ms when the excitation light irradiation start time is 0 ms.

(Calculation process)
The phosphorescence peak wavelength region λ ₁ = 446 nm (center wavelength), λ ₂ = 496 nm (center wavelength), λ ₃ = 551 nm (center wavelength), λ ₄ = 623 nm (center wavelength), and the first detection time T ₁ = lambda ₁ phosphorescent intensity _{I 21} at the time of 401ms, λ ₂ of the phosphorescence intensity _{I 22,} lambda ₃ of phosphorescence intensity _{I 23,} reads the phosphorescence intensity _{I 24} of the lambda ₄ from _{measurements,} I 21 = _0counts , I ₂₂ = 449 counts, I ₂₃ = 969 counts, I ₂₄ = 3584 counts. Second detection time _T 2 = _{λ 1} phosphorescent intensity I _'21, lambda ₂ of phosphorescence intensity I' of the time of 405ms _22, λ ₃ of phosphorescence intensity I _'23, lambda ₄ phosphorescence intensity I' _{When 24} was read from the measured values, I ′ ₂₁ = 0 counts, I ′ ₂₂ = 104 counts, I ′ ₂₃ = 290 counts, and I ′ ₂₄ = 3208 counts.

(Determination process)
Discrimination based on the phosphorescence intensity ratio of each peak wavelength in the first detection time T ₁ and the second detection time T ₂ is I ₂₁ / I ′ ₂₁ = 0, I ₂₂ / I ′ ₂₂ = 4.3, and I _23. / I ′ ₂₃ = 3.3 and I ₂₄ / I ′ ₂₄ = 1.1. When the determination reference value was determined as shown in Table 8, the true / false discrimination result was “true” as shown in Table 8.

(Comparative Example 1)
Next, in order to compare with the example of the afterglow light-emitting body of the present invention, the light-emitting body of the comparative example will be described. The raw materials having the composition shown in Table 9 were accurately weighed, thoroughly mixed in an ethanol solvent, and dried. The sufficiently mixed powder was put in an alumina container and baked at 1400 ° C. for 2 hours in a reducing atmosphere (N ₂ + H ₂ (4%)) to produce the phosphor of Comparative Example 1. The luminous body of Comparative Example 1 mainly contains a compound represented by a molar ratio of 2.65Ba · 0.3Ca · 0.985Mg · Si ₂ O ₈ : 0.05Eu · 0.015Mn.

  The fired phosphor of Comparative Example 1 was coarsely pulverized in an agate mortar, and the emission characteristics were measured with a spectrofluorometer (F-4500, manufactured by Hitachi High-Technologies Corporation). FIG. 13 shows fluorescence and phosphorescence spectra upon excitation with ultraviolet light at 365 nm. The fluorescence showed a single emission peak at 458 nm. Phosphorescence showed an emission peak at 622 nm. Visually, the fluorescent color was observed in dark blue and the phosphorescent color was observed in red.

  The afterglow measurement of the light emitter of Comparative Example 1 was performed. The afterglow time (lifetime) was 75.5 ms as a result of performing afterglow measurement using an excitation light source as an LED light source having a central wavelength of 365 nm and an irradiation time of 400 ms.

  The phosphor of Comparative Example 1 was pulverized by shaking and stirring with zirconia beads for 240 minutes in an ethanol solvent. After pulverization, the particle size of the powder after being washed with water a plurality of times and dried was measured with a CILAS particle size distribution meter 1064L, and the median value was 2.77 μm.

(Production and evaluation of comparative printed matter)
Using the phosphor of Comparative Example 1, a comparative screen ink composition 1 was prepared with a planetary ball mill (manufactured by Fritsch) with the formulation shown in Table 10.

  In the screen printing method, a 200-mesh printing plate was used, and after applying the comparative screen ink composition 1 of Comparative Example 1 to fine paper that was not fluorescently whitened with a solid image line, the ink was dried and Comparative Example 1 was dried. Comparative print 1 was produced.

  The comparative printed matter 1 of Comparative Example 1 was irradiated with 365 nm ultraviolet light, and blue fluorescence was observed. Further, when the ultraviolet light source was moved on the comparative printed matter 1, a portion where the light source was separated was observed as red phosphorescence. However, the visibility of phosphorescence was lower than the printed matter of Example 1 and Example 2.

  The phosphorescence spectrum of the comparative printed material 1 of Comparative Example 1 at excitation wavelengths of 254 nm and 365 nm is shown in FIG. Although the emission intensity was different when the excitation wavelength was different, the spectrum shape was similar and showed a single emission peak. Since the emission spectrum shape does not change at the excitation wavelengths of 254 nm and 365 nm, the discrimination method as shown in Example 1 cannot be taken.

Table 11 shows the authenticity determination results of the authenticity printed matter 1 and the printed matter of Comparative Example 1. If the reference value is determined as shown in Table 11 and the allowable error in determination is ± 10%, the intensity ratio in each wavelength region is within the reference value only for I ₁₁ / I ₂₁ and I ₁₄ / I _24. , I ₁₂ / I ₂₂ and I ₁₃ / I ₂₃ deviate from the standard values, and therefore the printed matter of the comparative example was determined to be “false”.

  Therefore, even if the composition of Patent Document 1 which is a publicly known technique is adjusted and the fluorescence characteristics are brought close to the light emitting material of the present invention, it becomes only a single peak in the phosphorescence spectrum and has the same light emitting characteristics as the present invention. It turned out that a luminescent material cannot be produced.

(Comparative Example 2)
Next, a comparative screen ink composition 2 was prepared by mixing commercially available light-emitting materials in the proportions shown in Table 12 in order to compare with the examples of afterglow phosphors of the present invention.

  In the screen printing method, a 200-mesh printing plate was used, and after applying the comparative screen ink composition 2 of Comparative Example 2 to fine paper that was not fluorescently whitened with a solid image line, the ink was dried and Comparative Example 2 was dried. Comparative print 2 was produced.

  The comparative printed matter 2 of Comparative Example 2 was irradiated with 365 nm ultraviolet light, and blue fluorescence was observed. Next, an ultraviolet light source was moved on the comparative printed material 2, but red phosphorescence could not be visually recognized.

  FIG. 15 shows the fluorescence spectrum of the comparative printed material 2 of Comparative Example 2 when the excitation wavelength is 365 nm and the phosphorescence spectrum when the excitation wavelengths are 254 nm and 365 nm. Since three peaks appear in the fluorescence spectrum, and one of these peak wavelength regions is the same as the phosphorescent peak wavelength region, the printed image formed by the luminescent ink comprising the afterglow phosphor of the present invention It has a light emission characteristic different from that of.

  In the phosphorescence spectrum of the comparative printed material 2 of Comparative Example 2, when the excitation wavelength was different, the spectrum shape was similar, although the emission intensity was different, and showed a single emission peak. The peak wavelength region showed a peak in the green region of 521 nm, unlike the printed image formed by the luminescent ink comprising the afterglow luminescent material of the present invention.

  Since the phosphorescence spectrum shape does not change at the excitation wavelengths of 254 nm and 365 nm, the discrimination method as shown in the first embodiment cannot be taken. However, a discrimination example in the case where the discrimination method similar to the authenticity discrimination printed matter 1 is taken. Indicates. Table 13 shows the authenticity determination results of the authenticity determination printed matter 1 and the comparative printed matter 2 of Comparative Example 2. Since the emission spectrum shape of the light-emitting screen ink composition 1 of the authenticity discrimination printed matter 1 and the comparison screen ink composition 2 of the comparative example 2 are different from each other, the detection wavelength region defined in the discrimination of the authenticity discrimination printed matter 1 is compared with the comparative example 2. Since the emission peak wavelength region of the comparative screen ink composition 2 does not enter, the detection wavelength region determined in the discrimination of the authenticity discrimination printed matter 1 does not fall within the reference value range. When the reference value is set as shown in Table 13 and the error allowed in the determination is ± 10%, the intensity ratio in each wavelength region of Comparative Example 2 is outside the reference value, and Comparative Print 2 of Comparative Example 2 is “ It was determined to be “false”.

  From these facts, it has been found that even if a light emitting material that is available is mixed and color-adjusted, the same light emission characteristics as in the present invention cannot be realized and imitation can be prevented.

Claims (8)

A phosphor represented by the following chemical formula, wherein M is not present or is Ca, and α, β, and γ are in the following ranges, and a plurality of phosphorescent peaks in a wavelength region different from the fluorescent peak An afterglow light-emitting body characterized by comprising:
(Ba · M) _3-α-β Mg _1-γ Si ₂ O ₈ ; Eu _α Tb _β Mn _γ
0.025 ≦ α ≦ 0.05
0.05 ≦ β ≦ 0.2
0.005 ≦ γ ≦ 0.05   2. The afterglow emission according to claim 1, wherein when M is Ca, α = 0.05, 0.05 ≦ β ≦ 0.1, 0.009 ≦ γ <0.02. body.   When light having a wavelength centered on the wavelength region 254 (nm) or the wavelength region 365 (nm) is irradiated, the fluorescence peak is present in the wavelength regions 446 to 458 (nm), and the wavelength regions 488 to 502 (nm) 3) The afterglow luminescent material according to claim 1 or 2, wherein the phosphorescent peak is present in a wavelength region 541 to 553 (nm) and in a wavelength region 621 to 626 (nm).   A luminescent ink comprising the afterglow luminescent material according to claim 1.   An authenticity printed matter having a printed image formed by the luminescent ink according to claim 4 on at least a part of the substrate. The authenticity determination method for authenticity determination printed matter according to claim 5,
Irradiating excitation light of a first wavelength range and a second wavelength range to the authenticity discrimination printed matter;
First detection time of each of the first phosphorescence characteristics after stopping the excitation light in the first wavelength range and the second phosphorescence characteristics after stopping the excitation light in the second wavelength range Phosphorescence detection for detecting each phosphorescence intensity from the first phosphorescence intensity to the fourth phosphorescence intensity, which is the value of the emission intensity in each detection wavelength band from the first detection wavelength band to the fourth detection wavelength band in Process,
Numerical processing is performed for calculating a relative ratio of the phosphorescence intensities in the detection wavelength ranges of the first detection time in the phosphorescence characteristics of both the first phosphorescence characteristic and the second phosphorescence characteristic. A calculation process;
A true / false discrimination method comprising a discrimination step of collating a relative ratio calculated in the calculation step with a predetermined reference value and determining that the value is within a predetermined reference value range.   In the phosphorescence detection step, the first phosphorescence characteristic after stopping the excitation light in the first wavelength region and the second phosphorescence characteristic after stopping the excitation light in the second wavelength region. Detecting each phosphorescence intensity in each detection wavelength region at each second detection time, and in the calculation step, in the phosphorescence characteristics of both the first phosphorescence characteristics and the second phosphorescence characteristics; The authenticity determination method according to claim 6, wherein numerical processing is performed for calculating a relative ratio of the phosphorescence intensities in the detection wavelength ranges of the first detection time and the second detection time. The authenticity determination method for authenticity determination printed matter according to claim 5,
Irradiating at least one excitation light of a first wavelength range and a second wavelength range to the authenticity discrimination printed matter;
The phosphorescence characteristic of at least one of the first phosphorescence characteristic after stopping the excitation light in the first wavelength range or the second phosphorescence characteristic after stopping the excitation light in the second wavelength range From the first phosphorescence intensity to the fourth phosphorescence, which is the value of the emission intensity in each of the detection wavelength bands from the first detection wavelength band to the fourth detection wavelength band at the first detection time and the second detection time. A phosphorescence detection step for detecting each phosphorescence intensity of the light intensity;
An operation step of performing numerical processing for calculating a relative ratio of the values of the respective phosphorescence intensities of the first detection time and the second detection time in at least one of the phosphorescence characteristics;
A true / false discrimination method comprising a discrimination step of collating a relative ratio calculated in the calculation step with a predetermined reference value and determining that the value is within a predetermined reference value range.

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