JP5610121B2 - Afterglow luminescent composition, afterglow ink composition, and authenticity printed matter - Google Patents

Description

  The present invention is an afterglow luminescence having a feature that a person who has been informed of the features of the assigned anti-counterfeiting technology can determine authenticity with a simple instrument but is not easily noticed by those who are not informed of the information. The present invention relates to a composition, an afterglow ink composition, and a true / false discrimination printed matter.

  For printed matter that requires security, such as securities, forgery prevention and falsification are required to prevent counterfeiting and tampering, or to distinguish counterfeit products from genuine products. .

  As one of the elements for preventing forgery of securities and authenticity determination, it has been proposed as an effective means to provide a specific light emitter such as fluorescent light or phosphorescent light partially or entirely.

  As a method for determining the authenticity of security printed matter to which these luminescent inks are applied, electromagnetic waves such as light containing energy that can excite the luminescent material on the printed matter, irradiation of radiation or electric field application, chemical reaction In a light emitting phenomenon of a light emitting element and / or a phosphor, a method is generally used in which a sensor detects an afterglow phenomenon that is emitted while being attenuated after application of excitation energy is stopped.

  Among the illuminants, the visible illuminant emits light by using a simple tool such as black light as an excitation source to authenticate the luminescence with the human eye and mechanically performing excitation and detection of the illuminant. An authentication method using strength and time as discriminating factors can be taken.

  In recent years, since light emitters and fluorescent inks can be obtained relatively easily, they can be easily obtained for applications that require more accurate detection and discrimination, such as security prints. It is desirable to use a light emitter having a light emission characteristic that is different from that of the light emitter that can be formed. Examples of light emitters having such characteristic light emission characteristics include a light emitter whose emission color changes according to an excitation wavelength irradiated with electromagnetic waves, etc., and a light emitter whose distribution of emission intensity is extremely different depending on the observation wavelength. Can be mentioned. In addition, a phosphor that has not only fluorescent light emission but also afterglow and has characteristic characteristics in the afterglow and can mechanically detect this afterglow characteristic is more effective.

As an example of a light emitter having the above characteristics, the applicant of the present invention uses p (BaO) · q (MgO) · r (Al ₂ O ₃ ) as a base material composition, Eu, Mn and / or Nd as an activator. An afterglow luminescent composition using a co-activated alkaline earth aluminate luminescent material, a method for producing the same, and a luminescent printed material are presented (for example, see Patent Document 1).

In addition, the applicant of the present invention sets the matrix material to pSrO · qBaO · rMgO · m (Al ₂ O ₃ ), and activates an alkaline earth aluminate phosphor that is co-activated with Eu, Mn and / or Dy. And a light-emitting printed matter using the composite light-emitting material using the same (see, for example, Patent Document 2).

  Patent Document 3 uses a fluorescent colorant and a phosphor that have different afterglow times, and verifies authenticity by confirming a change in emission color or a change in emission image caused by a difference in afterglow time. Ink materials, image forming methods, and printed materials that can be printed are disclosed (for example, see Patent Document 3).

JP 2009-102497 A JP 2009-102496 A JP 2005-67043 A

  However, in the inventions of Patent Document 1 and Patent Document 2, since the detection of the afterglow characteristics of the light emitter is suitable for machine reading, there is a problem that it is difficult to detect the afterglow characteristics without specific equipment. It was left.

  Patent Document 3 aims to visually check the emission color or emission image after stopping the excitation light irradiation by using a phosphor having a long afterglow time, although the emission colors of fluorescence and phosphorescence are different. Therefore, there is a possibility that it can be easily reproduced by a combination of known materials.

  The present invention is intended to solve the above-described problems, and has phosphorescent and phosphorescent light emission colors having different characteristics, and afterglow due to phosphorescence when a general observer visually recognizes the light emission characteristics. Although it is not easy to visually recognize that the time is different, a person who is informed of the light emission characteristics in advance has a remaining time that can be visually recognized by performing a specific confirmation method using a simple instrument. The present invention relates to a light-emitting composition, an afterglow ink composition, and a true / false discrimination printed matter.

  The present invention is an afterglow luminescent composition comprising at least one or more illuminants X and at least one or more illuminants Y, and the illuminant X and the illuminant Y have an emission color when irradiated with excitation light, Identical or different, the illuminant Y has an afterglow time after the excitation light stop is shorter than the illuminant X, and the afterglow time of the illuminant X is 10 ms or more and less than 1 s. It is an afterglow luminescent composition characterized by having different afterglow colors after excitation light is stopped.

  The afterglow light-emitting composition of the present invention is an afterglow light-emitting composition characterized in that the emission color when irradiated with excitation light and the afterglow color after excitation light stop have a complementary color relationship.

  The afterglow light-emitting composition of the present invention is an afterglow light-emitting composition characterized in that the light emitter X is a phosphor and the light emitter Y is a phosphor.

  The afterglow light-emitting composition of the present invention is an afterglow light-emitting composition characterized in that excitation light is ultraviolet light.

  In addition, the present invention is an afterglow ink composition comprising an afterglow luminescent composition mixed with a varnish.

  Moreover, this invention is use of the afterglow luminescent composition as a coating material or ink.

  The present invention is an authenticity printed matter having a printed image formed with an ink containing an afterglow luminescent composition on at least a part of a base material, the printed image being a fluorescent image when irradiated with excitation light. The emission color is different from the emission color of the afterglow after the excitation light is stopped, and when the excitation light is irradiated, the fluorescent image of the fluorescence emission is visually recognized. If the excitation light is stopped or the excitation light is moved quickly, the fluorescence image disappears. In addition, the authenticity determination printed matter is characterized in that an afterglow image having an emission color different from that of the fluorescent image is visually recognized.

  The present invention includes a step of visually observing fluorescence while irradiating the authenticity discrimination printed matter with excitation light, a step of quickly moving the excitation light in a direction away from the authenticity discrimination printed matter, and a true state when the excitation light is quickly moved. There is a method of visually observing phosphorescence of a false discrimination printed matter, and a true / false discrimination method for authenticity discrimination printed matter characterized by confirming that fluorescence and phosphorescence are different colors and performing authenticity discrimination.

  Since the afterglow luminescent composition of the present invention is different in fluorescence emission color and phosphorescence afterglow color and has a short afterglow time, it provides a genuineness discrimination printed matter with high secrecy in the authenticity discrimination element. be able to.

  Further, the afterglow luminescent composition of the present invention is short enough to allow the observer to visually recognize the afterglow time of phosphorescence, and by performing a specific confirmation method using a simple tool. In addition, since it is possible to detect a change in luminescent color in the afterglow luminescent composition, it is possible to provide a true / false discrimination method with good authenticity.

The figure which shows the definition method of afterglow time. The top view which shows authenticity determination printed material. The top view which shows the time of excitation light irradiation of authenticity determination printed matter. The top view which shows the authenticity discrimination | determination printed matter which kept the excitation light away. The emission spectrum in the authenticity discrimination printed matter of Example 1. The emission spectrum in the authenticity discrimination printed matter of Example 2. The emission spectrum in the authenticity discrimination printed matter of Example 3. The emission spectrum in the authenticity discrimination printed matter of Example 4. FIG. 9 is a plan view showing a genuineness determination printed matter of Example 5. FIG. 10 is a plan view showing when authenticity determination printed matter of Example 5 is irradiated with excitation light. The top view which shows the authenticity discrimination | determination printed matter of Example 5 which kept away excitation light. The emission spectrum of the printed matter of Comparative Example 1.

  The afterglow luminescent composition and the luminescent printed material according to some embodiments of the present invention will be described below, but the present invention is not limited thereto.

(Definition of afterglow time and illuminant X)
Here, the afterglow time (life) and the light emitter X in the present invention are defined. The afterglow time is an elapsed time when emission is not observed from 0 s when excitation is stopped. In the present invention, as shown in FIG. 1, the definition is made with the afterglow time (lifetime) in the means actually measured by the applicants. An LED light source having a central wavelength of 365 nm was used as an excitation light source, and a silicon photodiode detector was used for light emission detection. The excitation light turn-on time and turn-off time are controlled by a pulse generator, and as shown in FIG. 1A, the irradiation time is set to 400 ms, and the subsequent stop time is set to 5 s at maximum. The signal converted into the electric signal through the silicon photodiode detector is collected by the AD converter, and as shown in FIG. 1B, the time when the excitation light signal becomes 0 V is set to 0 s, and the signal of the illuminant. Is the afterglow time (life). Therefore, the luminous body X used in the present invention has an afterglow time (lifetime) of more than 10 ms and less than 1 s.

(Definition of luminous body Y)
Next, the light emitter Y in the present invention will be defined. The illuminant Y of the present invention is a phosphor having the same or different emission color as the illuminant X, and having a shorter afterglow time than the illuminant X, or an afterglow cannot be detected. (Reference: Iwanami Rikagaku 5th edition states that “it may be called a phosphor, including fluorescence and phosphorescence, but in general it is often a phosphor in the sense of including both emissions”.) Therefore, it can be defined including general light emitters.

  The composition of the present invention is expressed as “afterglow luminescent composition”. In the present invention, for the sake of convenience, light emission after the excitation light of the light emitter X is stopped is expressed as phosphorescence, and light emission of the light emitter Y is expressed as fluorescence. Further, the light emission during the excitation light irradiation of the afterglow luminescent composition and the authenticity discrimination printed material is expressed as fluorescence, and the light emission after the excitation light stop is expressed as phosphorescence or afterglow. Similarly, a material when used to develop the function as the light emitter X is expressed as a phosphor, and a material used when the function as the light emitter Y is expressed as a phosphor. To do.

  The illuminant X and the illuminant Y, which are materials for forming the afterglow luminescent composition of the present invention, are different as long as the luminescent color of the luminescent material Y and the luminescent color of the phosphor of the luminescent material X are different. Not only the light emitter X and one kind of light emitter Y, but also at least two kinds of light emitters X and two or more kinds of light emitters Y can be used. In this case, from the viewpoint of visibility, it is most preferable that the emission color of phosphorescence and the emission color of fluorescence have a complementary color relationship. This is because the visibility is the highest when both are complementary colors. Here, the complementary color includes a combination of two colors according to Herring's opposite color theory described in “Colorology Hideaki Chisiwa Fukumura Publishing 1983” P46.

  Moreover, in the afterglow light emitting composition in which the fluorescence emission color and the phosphorescence emission color are different, the afterglow time of the phosphor is desirably 10 ms or more and less than 1 s. If the afterglow time is less than 10 ms, the phosphorescence is difficult to see and the change in emission color cannot be recognized. In addition, when the afterglow time is 1 s or longer, the afterglow can be viewed for a long time, so that it is easily understood that some long afterglow luminescent composition is contained.

For example, the afterglow luminescent composition A ₁ having different emission colors of fluorescence and phosphorescence is formed by mixing the luminescent material X ₁ having the first luminescent color and the luminescent material Y ₁ having the second luminescent color. be able to. Note that the afterglow time of the light emitter X ₁ having the first emission color is longer than that of the light emitter Y ₁ having the second emission color.

Further, the afterglow luminescent composition A ₂ is prepared by mixing the luminescent material X ₁ having the first luminescent color, the luminescent material Y ₂ having the second luminescent color, and the luminescent material Y ₃ having the third luminescent color. Can be formed. The light-emitting body X ₁ having a first emission color, afterglow time is longer than the light-emitting element Y ₃ having a light emitter Y ₁ and the third emission color having a second emission color. There are many mixing methods, and a light emitter to be mixed may be selected according to the purpose.

Moreover, as the light emitter X and the light emitter Y constituting the afterglow light emitting composition, the afterglow time after the excitation light of the light emitter Y is stopped is shorter than that of the light emitter X, and the afterglow time of the light emitter X. Is not particularly limited as long as the material is 10 ms or more and less than 1 s, and Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu, CaMgSi ₂ O ₆ : Eu, Y (P, V) O ₄ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Mn, Zn ₂ SiO ₄ : Mn, (Ba, Sr, Mg) O · aAl ₂ O ₃ : Mn, LaPO ₄ : Ce, Tb, (Y, Gd) BO ₃ : Eu, Y ₂ O ₂ S: Eu, (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn, _3.5 MgO · _0.5 MgF ₂ · GeO ₂ : Mn, Y ₂ O ₂ S: Eu, ZnS _{: Ag, MgWO 4, ZnS:} Cu, A _{, BaMgAl 10 O 17: Eu,} Mn, SrBaMgAl 10 O 17: Eu, can be appropriately selected and used materials such as Mn. Further, as other light emitters, organic light emitters, fluorescent dyes, and the like can be used. Examples of the material that can be used as the light emitter X ₁ include BaMgAl ₁₀ O ₁₇ : Eu, Mn. The material that can be used as the light emitter Y ₁ is Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu. ^{2+ and the} like.

  In order to prepare an afterglow ink composition of the present invention, an aqueous varnish, a solvent type varnish, an oxidation polymerizable varnish, a radiation curable varnish, a radiation curable type and an oxidation polymerization hybrid varnish can be used. It can be selected according to the purpose and application. However, when using short-wave excitation light for authentication, the light-emitting effect is unlikely to decrease when an aqueous varnish or the like that absorbs short waves is used.

  In addition, the above-mentioned various varnishes are used, mixed well with an auxiliary agent, etc., adjusted for viscosity and the like so as to have characteristics suitable for application, and converted into an ink or paste. Although it depends on the application method, the blending ratio of the light emitters 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 afterglow ink composition is prepared by sufficiently dispersing the afterglow luminescent composition in the varnish using a three-roll mill, a ball mill, or a beadle. The kneading method and the appropriate viscosity are appropriately selected depending on the method for applying the afterglow ink composition.

  The afterglow ink composition may be made into an ink or paste by mixing other colorants or functional materials within a range that does not interfere with light emission, and is applied in advance on the base applied on the substrate in advance. You may do it. The base material is not limited to paper, and a plastic card or the like can also be used. Further, the base material color is not limited to white.

  As a method for applying the afterglow ink composition to the substrate by printing or coating, generally known printing methods can be used. Printing such as intaglio, letterpress, offset, screen, gravure, flexo, ink jet, etc. A method such as coating can be used, and it may be applied by a combination of these printing methods.

(Authentication printed matter)
Next, the authenticity printed matter using the afterglow ink composition of the present invention will be described. The pattern for applying the afterglow ink composition may constitute one pattern with one type of afterglow ink composition, or by performing combination printing with a plurality of types of afterglow ink compositions, It may be configured. At this time, when the afterglow ink composition has a different fluorescence emission color or phosphorescence emission color, the discrimination effect is enhanced. In addition, a desired pattern may be configured by performing combination printing with an afterglow ink composition and a non-afterglow ink composition. At this time, if the fluorescent color of the afterglow ink composition and the non-afterglow ink composition are the same color, the discrimination effect is enhanced.

  Next, the authenticity determination method using a simple instrument for authenticity determination printed matter will be described. In FIG. 2, an example of the authenticity discrimination printed matter by the afterglow ink composition was shown. A printed image 2 is formed on the authenticity printed matter 1 with an afterglow ink composition.

  As shown in FIG. 3, during irradiation of excitation light from the excitation light source 3, a printed image is emitted, and the fluorescent image 2b can be observed with the eyes of an observer. As shown in FIG. 4, when the authenticity printed matter 1 is left still, and the excitation light source 3 is continuously moved so as to swing in an arbitrary direction at a predetermined speed and irradiated with excitation light, observation is made. The afterglow image 2a by the ink composition is observed by an observer with a color different from the emission color during excitation light irradiation. The predetermined speed of moving the excitation light source 3 is preferably within the afterglow time in the phosphor. By continuously moving the excitation light source, the emission color of the afterglow luminescent composition is fluorescent. It changes continuously from the hue at the time of light emission to the hue at the time of afterglow. Even if the authenticity determination printed matter 1 is moved and observed while the excitation light source 3 is left stationary, the same observation can be made. Further, the moving distance of the excitation light source 3 refers to the distance from the position immediately above where the printed image is most excited until the fluorescence emission color disappears to become the afterglow emission color.

  Since the authenticity determination printed matter 1 of the present invention can detect the presence or absence of light emission during irradiation and afterglow after irradiation stop by irradiating ultraviolet light, it can be determined by a known machine. For example, a known afterglow detection device can be used for detecting afterglow. Further, the discrimination accuracy is improved by detecting an output within a predetermined threshold range according to the emission intensity of the luminescent printed matter.

As a more accurate machine discrimination method, for example, it can be discriminated by an apparatus proposed in Japanese Patent Laid-Open No. 2006-266810. The discrimination method by this apparatus irradiates excitation light of one wavelength region, and irradiates excitation light with different wavelength regions (λ ₀ , λ ₁ ,... Λ _x ) by a plurality of light receiving units (T ₀ ). And after receiving the excitation light irradiation (T ₁ ), the emission intensity of T ₀ λ ₀ , T ₀ λ ₁ , T ₀ λ _x , T ₁ λ ₀ , T ₁ λ _1, and T ₁ λ _x is designated in advance. This is a method of discriminating by comparing with the emission intensity value.

Further, as a determination method using another machine, for example, the determination can be performed by an apparatus proposed in Japanese Patent Application Laid-Open No. 2006-275578. Discriminating method according to this apparatus, irradiated with excitation light of a single wavelength band, in the excitation light irradiation (T ₀₎ and received after the excitation light irradiation stop (T _1), the spectrum S ₀ of T ₀ and T ₁ it is to determine and confirm the spectral shape of the spectrum S _1. Moreover, a spectrum may be 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 and λ ₂ may be followed. The spectral distribution of the obtained spectrum can be further calculated by a computer and compared as colorimetric values (x, y, Y or L ^* , a ^* , b ^* ) for discrimination.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these examples.

An afterglow flexographic ink composition W ₁ was prepared with the composition shown in Table 1 using an afterglow luminescent composition in which the illuminant X ₁ (red phosphor) and the illuminant Y ₁ (blue phosphor) were mixed. did. The kneading was performed with a planetary ball mill (manufactured by Fritsch).

At flexographic printing method, an anilox ruling 55Line / cm, with ultraviolet irradiation After imparting afterglow flexographic ink composition W ₁ on a high-quality paper that has not been optically brightened by the line drawing like symbol comprising a solid portion, The ink was dried to produce a true / false discrimination printed matter. The fluorescence and phosphorescence spectrum of the printed material for authenticity determination is obtained using a spectrofluorometer F-4500 (Hitachi), and the fluorescence spectrum of 365 nm ultraviolet light excitation and the phosphorescence spectrum for 10.2 ms after the acquisition timing is 2 ms. Is shown in FIG.

  Authenticity discrimination was performed on the printed matter using the authenticity determination method using a simple instrument. When a handy type UV light was used for the authenticity printed matter and irradiated with 365 nm ultraviolet light, blue-violet fluorescence was observed. Next, when the UV light irradiated on the printed material for authenticity determination was moved left and right or up and down, red afterglow was visually recognized.

The authenticity determination printed matter was determined using the authenticity determination device and the determination method described in Japanese Patent Application Laid-Open No. 2006-266810. The excitation light of the LED having a central wavelength of 365 nm is irradiated, and a sharp cut filter L39 and bandpass filters BPB-60 and BPB-45 manufactured by Fuji Film Co., Ltd. are inserted on the light receiving side, and 600 nm (λ ₁ ) or 450 nm ( The light emission outputs in two wavelength ranges with λ ₃ ) as the center wavelength were acquired by the two light receiving sections. When the excitation light is irradiated for 400 ms and the acquisition timing is during excitation light irradiation (T ₀ ) and 10 ms after irradiation stop (T ₁ ), output values of 520 mV and 840 mV are obtained at λ ₁ and λ ₃ at T ₀ , respectively. , T ₁ gave an output value of 295 mV only for λ ₁ , and the output value at λ ₃ was almost 0V. From this result, it was confirmed that a phosphor having two fluorescent emission peaks of λ ₁ and λ ₃ and _one phosphorescent peak of λ ₁ was given.

Using an afterglow luminescent composition in which the illuminant X ₁ (red phosphor) and the illuminant Y ₂ (green phosphor) are mixed, the afterglow screen ink composition W ₂ with the composition shown in Table 2 is used as a planet. It was prepared with a mold ball mill (manufactured by Fritsch).

  A screen printing machine (Mino Group) was used to print on fine paper with a patterned pattern using a 200 mesh plate. After printing, ultraviolet rays were irradiated by an ultraviolet irradiation device, and the ink was dried to obtain a true / false discrimination printed matter. FIG. 6 shows a fluorescence spectrum of the true / false discrimination printed matter excited by ultraviolet light at 365 nm and a phosphorescence spectrum of 10.2 ms after the acquisition timing is 2 ms after the irradiation is stopped.

  Authenticity discrimination was performed on the authenticity printed matter using a true / false discrimination method using a simple instrument. When a handy type UV light was used for the authenticity printed matter and irradiated with 365 nm ultraviolet light, green fluorescence was observed. Next, when the UV light irradiated on the authenticity discrimination printed material was moved left and right or up and down, red afterglow was visually recognized. Since the fluorescent color and the phosphorescent color are almost complementary, the afterglow is highly visible.

Using an afterglow luminescent composition in which an illuminant X ₂ (green phosphor) and an illuminant Y ₃ (red phosphor) are mixed, the afterglow screen ink composition W ₃ is a planet with the composition shown in Table 3. It was prepared with a mold ball mill (manufactured by Fritsch).

  Using a gravure coater, a 135 Line / inch plate surface was coated on a coated paper not fluorescently whitened in a bar shape, and then the ink was dried to obtain a true / false discrimination printed matter. FIG. 7 shows the fluorescence spectrum of 365 nm ultraviolet light excitation and the acquisition timing of the printed material for authenticity discrimination, and the phosphorescence spectrum for 10.2 ms after 2 ms from the stop of irradiation.

  Authenticity discrimination was performed on the authenticity printed matter using a true / false discrimination method using a simple instrument. When a handy type UV light was used for the authenticity printed matter and irradiated with 365 nm ultraviolet light, red fluorescence was observed. Next, when the UV light irradiated on the authenticity determination printed matter was moved left and right or up and down at a position closer to the authenticity determination printed matter, green afterglow was visually recognized. Since the fluorescent color and the phosphorescent color are almost complementary, the visibility of the phosphorescent color was high.

Using an afterglow luminescent composition in which an illuminant X ₃ (green phosphor) and an illuminant Y ₄ (red phosphor) are mixed, the afterglow screen ink composition W ₄ is a planet with the composition shown in Table 4. It was prepared with a mold ball mill (manufactured by Fritsch).

  A screen printing machine (Mino Group) was used to print on fine paper with a patterned pattern using a 200 mesh plate. After printing, ultraviolet rays were irradiated by an ultraviolet irradiation device, and the ink was dried to obtain a true / false discrimination printed matter. FIG. 8 shows the fluorescence spectrum of 365 nm ultraviolet light excitation and the acquisition timing of the printed material for authenticity determination, and the phosphorescence spectrum for 10.2 ms after 2 ms from the stop of irradiation.

  Authenticity discrimination was performed on the authenticity printed matter using a true / false discrimination method using a simple instrument. When authenticity printed matter was irradiated with 365 nm ultraviolet light using a handy type UV light, blue-green fluorescence was observed. Next, when the UV light irradiated on the authenticity determination printed matter was moved left and right or up and down at a position closer to the authenticity determination printed matter, green afterglow was visually recognized.

An example in which a pattern is formed by combination printing using an afterglow ink composition and a non-afterglow ink composition will be described. Afterglow flexo ink composition W ₅ and non-afterglow flexo ink composition W ₆ were prepared by mixing the color pigments with the formulation shown in Table 5.

At flexographic printing method, an anilox ruling 55Line / cm, as shown in FIG. 9, petals 2 and petals 2'A by afterglow flexographic ink composition W _5, a non afterglow flexographic ink composition W ₆ Printed image 2 having “B” was printed, and the ink composition was dried by irradiating with ultraviolet rays to produce authenticity printed matter 1 ′.

  When a handy type UV light was used for the authenticity printed matter 1 'and irradiated with ultraviolet rays of 365 nm, as shown in FIG. 10, a fluorescent image 2'b that emitted fluorescence in yellow-green was observed. Next, when the UV light irradiated onto 1 ′ of the authenticity discrimination printed matter is moved left and right or up and down, only the afterglow image 2′a shows orange afterglow as shown in FIG. 'B afterglow was not visible. It was confirmed that the effect of the present invention can be visually confirmed even in a true / false discrimination printed matter using an afterglow ink composition in which a color pigment is mixed within a range that does not interfere with light emission.

(Comparative Example 1)
Using the afterglow no illuminant to produce a screen ink composition Z ₁ in the formulation shown in Table 6. The kneading was performed with a planetary ball mill (manufactured by Fritsch).

  A screen printing machine (Mino Group) was used to print on fine paper with a patterned pattern using a 200 mesh plate. After printing, ultraviolet rays were irradiated by an ultraviolet irradiation device, and the ink was dried to obtain a comparative printed matter. FIG. 12 shows the fluorescence spectrum of 365 nm ultraviolet light excitation of the comparative printed material, the acquisition timing, and the phosphorescence spectrum for 10.2 ms after 2 ms from the stop of irradiation. As a result, as shown in FIG. 12, almost no phosphorescence could be detected.

  When a handy type UV light was used for the comparative printed matter and irradiated with ultraviolet rays of 365 nm, blue-green fluorescence was observed. Further, afterglow was not visually recognized when the UV light irradiated on the comparative printed material was moved left and right or up and down.

(Comparative Example 2)
Using long emitters afterglow, to prepare a screen ink composition Z ₂ in the formulation shown in Table 7. The kneading was performed with a planetary ball mill (manufactured by Fritsch).

  A screen printing machine (Mino Group) was used to print on fine paper with a patterned pattern using a 200 mesh plate. After printing, ultraviolet rays were irradiated by an ultraviolet irradiation device, and the ink was dried to obtain a comparative printed matter.

  When a handy type UV light was used for the comparative printed matter and irradiated with ultraviolet rays of 365 nm, red fluorescence was observed. Next, when the UV light irradiated on the comparative printed material was moved left and right or up and down, green afterglow could be visually recognized. Thereafter, the UV light was completely turned off and the comparative printed material was observed. As a result, green afterglow was continuously observed. Therefore, it could be easily recognized that some long afterglow luminescent composition was included.

(Comparative Example 3)
Using long emitters afterglow was prepared afterglow screen ink composition Z ₃ in the formulation shown in Table 8. The kneading was performed with a planetary ball mill (manufactured by Fritsch).

  A screen printing machine (Mino Group) was used to print on fine paper with a patterned pattern using a 200 mesh plate. After printing, ultraviolet rays were irradiated by an ultraviolet irradiation device, and the ink was dried to obtain a comparative printed matter.

The comparison printed material was subjected to authenticity determination using an authenticity determination method using a simple instrument. When a handy type UV light was used for the comparative printed matter and irradiated with ultraviolet rays of 365 nm, blue-green fluorescence was observed. Next, comparison when the printed matter UV light was irradiated on the A ₃ moves left and right or up and down, when it could not be visually clear afterglow was observed to completely turn off the UV light, weak orange Afterglow was observed continuously. Therefore, it was recognized that some long afterglow luminescent composition was included.

1, 1 'authenticity determination printed matter 2, 2' printed image 2a, 2'a afterglow image 2b, 2'b fluorescent image 2'A afterglow image 2'B non-afterglow image 3 excitation light source

Claims (6)

An afterglow light-emitting composition comprising at least one light emitter X and at least one light emitter Y,
The luminous body Y has a shorter afterglow time after the excitation light stops than the luminous body X,
The afterglow time of the light emitter X is 10 ms or more and less than 1 s ,
And light emission color at the time of the excitation light irradiation, different afterglow color after stopping the excitation light, and light emission color at the time of the excitation light irradiation, Ri afterglow color complementary relationship near after stopping the excitation light,
An afterglow light-emitting composition, which is used for visually distinguishing between the emission color when irradiated with excitation light and the afterglow color after stopping excitation light .

  The afterglow light-emitting composition according to claim 1, wherein the phosphor X is a phosphor, and the phosphor Y is a phosphor.   The afterglow light-emitting composition according to claim 1, wherein the excitation light is ultraviolet light.   An afterglow ink composition comprising the afterglow luminescent composition according to any one of claims 1 to 3 and a varnish.   Use of the afterglow luminescent composition according to any one of claims 1 to 3 as a paint or ink. An authenticity printed matter having a printed image formed by the afterglow ink composition according to claim 4 on at least a part of the substrate,
The printed image is different in the emission color of fluorescence when irradiated with excitation light and the emission color of afterglow after the excitation light is stopped,
By continuously moving the distance from the printed image that irradiates the printed image to the excitation light at a predetermined speed, the luminescent color due to fluorescence is continuously changed from the luminescent color due to afterglow to be visually recognized. Authenticity discrimination printed matter characterized by authenticity discrimination.

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