JP5799434B2 - Afterglow luminescent material and method for producing the same, afterglow luminescent ink composition, and authenticity printed matter - Google Patents

Description

  The present invention relates to an afterglow illuminant suitable for authenticity determination and to an afterglow illuminant that can be manufactured in a single process.

  For printed materials that require security, such as securities, forgery prevention and falsification are essential to prevent counterfeiting and tampering and to distinguish counterfeit products from new products. ing.

  Providing a specific light emitter such as fluorescent light or phosphorescent light partially or entirely as one of the anti-counterfeiting and authenticity determination elements of securities has been proposed as an effective means.

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

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

  In recent years, since phosphors and fluorescent inks are relatively easily available, for applications that require more accurate detection and discrimination, such as security prints, It is desirable to use light emitters having different characteristics of light emission. Examples of light emitters having such characteristic light emission characteristics include light emitters whose emission color changes according to the excitation wavelength irradiated with electromagnetic waves, etc., and light emitters whose emission intensity distribution is extremely different depending on the observation wavelength. As mentioned. Further, not only fluorescent light emission but also a light emitter that has afterglow and has characteristic characteristics in the afterglow is more effective.

As an example of the light emitter having the above-described characteristics, the applicant of the present invention sets the composition of the base material to p (BaO) · q (MgO) · r (Al ₂ O ₃ ), Eu, Mn and An afterglow phosphor using a Nd co-activated alkaline earth aluminate phosphor, a method for producing the phosphor, 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 composition to pSrO · qBaO · rMgO · m (Al ₂ O ₃ ), and as an activator, Eu, Mn and / or Dy co-activated alkaline earth aluminate phosphor. 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 can authenticate the authenticity by confirming the change in emission color or emission image caused by the difference in afterglow time. An ink material, an image forming method, and a printed material are shown (for example, see Patent Document 3).

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

  However, since the afterglow characteristics of the light emitters of Patent Document 1 and Patent Document 2 are intended to be discriminated by machine reading, there remains a problem that there is little change in emitted color according to the excitation wavelength.

  In addition, Patent Document 3 assumes that the emission color or emission image after stopping the excitation light irradiation is visually confirmed although the emission colors of fluorescence and phosphorescence are different. There was a fear that it was easily understood that the phosphor was used.

  The present invention is intended to solve the above-described problems, and exhibits different emission colors depending on the excitation wavelength, has different characteristics of emission colors of fluorescence and phosphorescence, and the phosphorescence afterglow time is visually observed. The present invention relates to an afterglow luminescent material that is as short as possible.

The present invention has the _formula: represented by _{(M k Ba a-x Eu} x) (a + k) O · (Mg b-y Mn y) bO · c (SiO 2), ( wherein, M is an alkaline earth Metals Ca (calcium), Sr (strontium), k is 0 or 0.3, a real number in the range of 2 ≦ a ≦ 3.5, and in a range of 0.75 ≦ b ≦ 3 A real number, a real number in the range of 1.5 ≦ c ≦ 3, a real number in the range of 0.01 ≦ x ≦ 0.2, and a range of 0.02 ≦ y ≦ 0.4 It is an afterglow illuminant represented by the following formula: and the emission color of the fluorescence after excitation light irradiation is different from the emission color of the afterglow after the excitation light is stopped, and the afterglow time after the excitation light is stopped Is an afterglow illuminant characterized in that it is 2 ms to 5 s.

In the present invention, k = 0 or 3, a = 3, b = 1, c = 2, 0.05 ≦ x ≦ 0.1, 0.05 ≦ y ≦ It is an afterglow light-emitting body characterized by being 0.25.

  In addition, the present invention provides the afterglow light emitter, wherein the afterglow wavelength has a peak wavelength centered at least at 620 nm, and the afterglow time is from 10 ms to 1 s.

The present invention also includes a blending step of blending a matrix material containing chemical formulas Ba, Mg, and SiO ₂ , and raw materials of an activator that is Eu and Mn, a mixing step of mixing the blended raw materials, and a mixing step After the completion, the dried mixture is fired in a reducing atmosphere at a firing temperature of 1200 ° C. to 1480 ° C. for 0.5 hours to 5 hours, and the post-treatment step of pulverizing and classifying after washing the mixture after the firing step It is a manufacturing method of the afterglow light-emitting body characterized by comprising.

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

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

  The present invention is the use of an afterglow ink composition for producing authenticity printed matter.

  The afterglow illuminant of the present invention can be used in a wide range of security products because it increases the machine discrimination accuracy of security printed matter using the afterglow illuminant and widens the authentication range using simple tools. There is an effect that can be done.

  Moreover, since the afterglow light-emitting body of the present invention can impart light emission characteristics with high secrecy, it has the effect of being able to provide an authenticity determination element with a high security level.

An example figure which shows the manufacturing process of the afterglow light-emitting body of this invention. The figure which shows the emission spectrum of the afterglow light-emitting body in excitation wavelength 365nm as one embodiment of this invention. The excitation spectrum of light emission in one embodiment of the present invention. The figure which shows the emission spectrum of the afterglow light-emitting body in excitation wavelength 437nm as one embodiment of this invention. The figure which shows the phosphorescence spectrum acquired after light irradiation stop number ms and 5 s of the afterglow light-emitting body in excitation wavelength 254nm as one embodiment of this invention. The figure which shows the measuring method of afterglow time. The figure which shows an example of the machine discrimination | determination method in the afterglow light-emitting body of this invention. The figure which shows an example of the machine discrimination | determination method in the afterglow light-emitting body of this invention. The figure which shows an example of the machine discrimination | determination method in the afterglow light-emitting body of this invention. The emission spectrum in the afterglow light-emitting body 1- (1) of Example 1 when the excitation wavelength is 365 nm. The X-ray diffraction chart in the afterglow light-emitting body 1- (1) of Example 1. FIG. The emission spectrum in the afterglow light-emitting body 2- (1) of Example 2 when the excitation wavelength is 365 nm. The emission spectrum in the afterglow light-emitting body 3- (3) of Example 3 when the excitation wavelength is 365 nm. The emission spectrum in the authenticity discrimination printed matter of Example 4 when the excitation wavelength is 365 nm. The emission spectrum in the authenticity determination printed matter of Example 5 when the excitation wavelength is 365 nm. Example 6 Fluorescence spectrum at an excitation wavelength of 365 nm in the authenticity discrimination printed matter. The emission spectrum at the excitation wavelength 365nm in the light-emitting body of the comparative example 1. The emission spectrum at the excitation wavelength of 365 nm of the printed matter of 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. The composition of afterglow luminescent material of the present invention, the chemical formula: (MkBa-xEux) (a + k) is indicated by O · (Mgb-yMny) bO · c (SiO 2), M in the formula is an alkaline earth metal Ca (calcium), Sr (strontium), k is 0 or 0.3, a is 2 ≦ a ≦ 3.5, b is 0.75 ≦ b ≦ 3, c is 1.5 ≦ c ≦ 3, x is 0.01 ≦ x ≦ 0.2, and y is in the range of 0.02 ≦ y ≦ 0.4.

Further, k = 0 or 3, a = 3, b = 1, c = 2, 0.05 ≦ x ≦ 0.1, and 0.05 ≦ y ≦ 0.25. It is an afterglow illuminant.

  Next, the manufacturing process of the afterglow light-emitting body of the present invention will be described. As shown in FIG. 1, 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 mixture obtained by drying after completion of the mixing process in a reducing atmosphere. It comprises a firing step for firing at the bottom and a post-treatment step for washing, pulverizing and classifying the mixture after the firing step.

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 the chemical formulas Ba, Mg and SiO ₂ and raw materials of activators which are Eu and Mn are blended. In the production of the afterglow phosphor of the present invention, the raw material of the metal serving as the emission center and the compound serving as the host material may be any material that can be converted into an oxide after high-temperature firing. A thing, an oxide, etc. can be used.

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

  In the firing step, the mixture dried after completion of the mixing step is fired in a reducing atmosphere at a firing temperature of 1200 ° C. to 1480 ° C. for 0.5 hours to 5 hours. Specifically, the raw material mixture is put in a heat-resistant container such as an alumina crucible and the like in a reducing atmosphere such as nitrogen gas or argon gas containing hydrogen gas at a high temperature of 1200 ° C. to 1480 ° C. for 0.5 hour or more, preferably 1 It can be produced by baking for more than an hour. In particular, when fired at a high temperature of 1400 ° C. or higher and lower than the melting temperature, an afterglow luminescent material having high emission intensity of both fluorescence and phosphorescence can be obtained with a single material. Further, when firing the above-mentioned afterglow illuminant, a compound containing fluorine or boron may be added for the purpose of controlling particle growth. It can be used within the range not to become.

  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. The body can be made.

  In addition, since the firing temperature affects the light emission characteristics of the generated afterglow phosphor, it must be as high as possible within the range in which the raw material mixture does not melt. For example, when firing at 1480 ° C., the fluorescence emission color Since an afterglow illuminant having a large color difference between the phosphorescent color and the phosphorescent color is obtained, it is useful for visual authentication. When fired at a lower temperature of 1400 ° C. or lower, an afterglow illuminant having two or more large peaks in the fluorescence spectrum is obtained, which is useful for machine authentication.

  In the post-treatment step, the produced afterglow phosphor is washed, pulverized, and classified by a known method according to the use. As a printing ink, when an afterglow illuminant is applied to a substrate by printing, 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 by a printing method so that it is not too fine.

  FIG. 2 is a diagram showing a fluorescence and phosphorescence spectrum of an afterglow luminescent material according to an embodiment of the present invention when the excitation wavelength is 365 nm. As shown in FIG. 2, the afterglow illuminant of the present invention has different dominant wavelengths in the emission spectra of fluorescence and phosphorescence. That is, the observed emission colors are different.

  FIG. 3 is a diagram showing an excitation spectrum of the afterglow luminescent material in the embodiment of the present invention when the fluorescence wavelength is 510 nm. The intensity increases from a short wavelength to a long wavelength, and has a peak in the visible light region of 400 nm or more. That is, it has been shown that the afterglow luminescent material of the present invention can induce fluorescence emission not only with ultraviolet light but also with blue light. FIG. 4 shows a fluorescence spectrum at an excitation wavelength of 437 nm. When excited at 437 nm in the visible light region, only a single peak at 511 nm appeared.

  FIG. 5 is a diagram showing phosphorescence spectra of the afterglow luminescent material according to one embodiment of the present invention, acquired from 2 ms to 10.2 ms and several tens of seconds after stopping the light irradiation at the excitation wavelength of 254 nm. The spectrum acquired after 2 ms to 10.2 ms was red with a peak wavelength of 620 nm, and the spectrum acquired after 5 s showed a green emission color with a peak wavelength of 511 nm. The emission characteristics of the afterglow luminescent material of the present invention are shown in Table 1 with the excitation wavelength and measurement timing as parameters. In addition, the numerical value shown in Table 1 is a typical one, and varies depending on each afterglow light emitter.

The afterglow time (lifetime) of the afterglow illuminant and the measuring method thereof in one embodiment of the present invention will be described. 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 were controlled by a pulse generator, and as shown in FIG. 6A, the irradiation time was 400 ms, and the subsequent stop time was 5 s at maximum. The signal converted to the electrical signal through the silicon photodiode detector is AD converted by the AD converter, and the time when the excitation light signal becomes 0 V is set to 0 s, and the time after which the afterglow light emitter signal becomes 0 V Is the afterglow time (lifetime). The afterglow phosphor in one embodiment of the present invention has an afterglow time (life) of 91 ms with an irradiation time of 400 ms and a wavelength of 600 nm as the central wavelength in excitation at 365 nm, and the afterglow after 50 ms after stopping the excitation light irradiation. Light detection was possible. The afterglow is 2 ms to 5 s, the visible afterglow is 10 ms or more, and more preferably, it has an afterglow time of 20 ms or more from the viewpoint of visibility. Furthermore, in consideration of confidentiality, 5 s or less is preferable, and 1 s or less is more preferable.

  The preparation of the afterglow luminescent ink composition will be described. Depending on the method for applying the produced afterglow luminescent material, the mixture is sufficiently mixed with a binder, an auxiliary agent, and the like, and the viscosity and the like are adjusted so as to have characteristics suitable for the application, and the ink is formed or pasted. Although it depends on the application method of the afterglow luminescent ink composition, the blending ratio of the afterglow luminescent material may be about 1 to 60% by weight, and from the viewpoint of emission intensity and economy, it is 10 to 40% by weight. % Is more desirable.

  The afterglow 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, and is previously stacked on a base provided on a substrate. May be given.

  As a method for applying the afterglow luminescent ink composition to a substrate by printing or coating, generally known printing or coating methods such as intaglio, letterpress, offset, screen, gravure, flexo or ink jet are used. It may be provided by a combination of these printing methods. The printed matter coated with the afterglow luminescent ink composition thus prepared is defined as a true / false discrimination printed matter.

  Further, examples of the method for discriminating the produced authenticity discrimination printed material include a method for visually discriminating using a simple instrument and a method using a machine.

  First, a method for visual discrimination using a simple instrument will be described. A hand-held ultraviolet lamp such as black light is irradiated to the authenticity printed matter, and the fluorescence emission is visually observed. The irradiation conditions at this time are referred to as static irradiation conditions. Next, turn off the UV lamp instantaneously, or quickly scan the printed matter surface to the distance where the afterglow illuminant is not excited, and visually check the phosphorescence of a color different from the fluorescent color. To do. The irradiation conditions at this time are referred to as dynamic irradiation conditions. In addition, when the ultraviolet lamp irradiated on the authenticity determination printed material surface is scanned up and down or left and right, different colors of emission colors having a complementary color depending on the scanning direction can be visually recognized. For example, if the lamp is first moved to the right side so that it passes over the printing surface, red phosphorescence can be visually recognized, and when returning to the left side so that the UV lamp scanned on the right side passes over the printing surface, the green color should be changed. It can be visually recognized.

  As a general authenticity determination method using a machine, there is a method of irradiating an authenticity determination printed matter with ultraviolet light, detecting light emission during irradiation and presence / absence of afterglow after irradiation stop. The discrimination accuracy is improved by comparing with the output of a predetermined threshold range according to the light emission intensity of the authenticity discrimination printed matter. For detecting afterglow, an afterglow detection device or the like can be used.

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 range, and radiates excitation light (T ₀ ) and excitation light in different wavelength ranges (λ ₁ , λ ₂ and λ ₃ ) by three light receiving sections, respectively. Light is received several tens of ms after the stop of irradiation (T ₁ ), and the emission intensities of T ₀ λ ₁ , T ₀ λ ₂ , T ₀ λ ₃ , T ₁ λ ₁ , T ₁ λ ₂ and T ₁ λ ₃ are determined in advance. This is a method of discriminating by comparing with a specified emission intensity value. In the case of the afterglow luminescent material of the present invention, as shown in FIG. 7, for example, the center wavelength of the excitation light can be measured as 365 nm, λ ₁ = 620 nm, λ ₂ = 510 nm, and λ ₃ = 450 nm.

Further, another discrimination method using the apparatus proposed in Japanese Patent Laid-Open No. 2006-266810 will be described. Excitation light of two different wavelength regions is irradiated, and at least two different wavelength regions (λ ₁ and λ ₂ ) are emitted at least two light receiving sections after several tens of milliseconds (T ₁ ) after excitation light irradiation is stopped. Receive light after a few seconds (T ₂ ) after stopping irradiation, and compare the emission intensity of T ₁ λ ₁ , T ₁ λ ₂ , T ₂ λ ₁ and T ₂ λ ₂ with the emission intensity value specified in advance. It is a method to discriminate by. In the case of the afterglow illuminant of the present invention, for example, as shown in FIG. 8, the center wavelength of the excitation light 1 is 365 nm, the center wavelength of the excitation light 2 is 254 nm, λ ₁ = 620 nm, and λ ₂ = 510 nm. be able to.

Another discrimination method using a device similar to the device proposed in Japanese Patent Laid-Open No. 2006-266810 will be described. Excitation light of two different wavelength regions is irradiated, and at least two different wavelength regions (λ ₁ and λ ₂ ) are emitted during excitation light irradiation (T ₀ ) and after excitation light irradiation is stopped by at least two light receiving units, respectively. After 10 ms (T ₁ ), the light is received, and the light emission intensities of T ₀ λ ₁ , T ₀ λ ₂ , T ₁ λ ₁ and T ₁ λ ₂ are compared with the light emission intensity values specified in advance. It is a method to do. As a simple method, it is also possible to discriminate by comparing only the emission intensity value at T ₀ in excitation light irradiation in different wavelength regions. In the case of the afterglow luminescent material of the present invention, for example, as shown in FIG. 9, the center wavelength of the excitation light 1 is 365 nm, the center wavelength of the excitation light 2 is 430 nm, λ ₁ = 620 nm, λ ₂ = 510 nm, and λ _3. = 450 nm can be measured.

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. 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. 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 and discriminated as colorimetric values (x, y, Y or L ^* , a ^* , b ^* ).

  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 2 were accurately weighed, thoroughly mixed in an ethanol solvent, and dried. The sufficiently mixed powder was put in an alumina container and fired at 1420 ° 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 2.95Ba · 0.9Mg · Si 2 O 8: 0.05Eu · 0.062 Mn.

  The afterglow phosphor 1- (1) was roughly pulverized in an agate mortar, and the emission characteristics were measured with a spectrofluorometer (F-4500, manufactured by Hitachi, Ltd.). FIG. 10 shows the fluorescence and phosphorescence spectra. It was. Fluorescence showed the highest fluorescence emission peak at 510 nm and peaks at 447 nm and 621 nm. Comparing the spectra of 365 nm ultraviolet light excitation and 302 nm excitation, the peak intensity at 510 nm is relatively low at the time of 302 nm excitation. This indicates that the emission color varies depending on the excitation wavelength. In fact, the fluorescent color visually observed was yellowish white when excited at 365 nm and pink when excited at 302 nm. In excitation with ultraviolet light at 365 nm, phosphorescence showed a peak at 622 nm and was visually a red phosphorescent color. The phosphorescence spectrum obtained after irradiating with 254 nm ultraviolet light for 2 minutes and after 5 seconds showed a peak at 511 nm. In addition, about the figure which shows the fluorescence and phosphorescence spectrum after FIG. 10, in order to show the position of an emission peak, the fluorescence emission spectrum and the phosphorescence emission spectrum are shown, and as actual emission intensity, fluorescence emission intensity is shown. Is higher.

  Afterglow measurement of the afterglow luminous body 1- (1) was performed. As a result of performing afterglow measurement using an excitation light source as an LED light source having a center wavelength of 365 nm, an irradiation time of 400 ms, and a wavelength of 600 nm as a center wavelength, the afterglow time (lifetime) was 105 ms.

  The afterglow phosphor 1- (1) was pulverized by shaking with zirconia beads for 280 minutes in an ethanol solvent. As a result of measuring the particle size of the powder after pulverization, washing with water several times and drying with a CILAS particle size distribution meter 1064L, the median values were 5.87 μm, 10%, 0.79 μm, 90%, 15.48 μm.

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

Similarly, afterglow phosphors 1- (2) to 1 under the same conditions as afterglow phosphor 1- (1) except that the substitution ratios of Eu and Mn were changed as shown in Table 3. -(17) was prepared, and the emission characteristics were measured. The integral values of the fluorescence and phosphorescence spectra were calculated, and the relative values when the afterglow phosphor 1- (1) is set to 100 are shown in Table 3. From this result, it was found that the composition in which the emission intensity of both fluorescence and phosphorescence increases is the case where 0.05 mol of Eu and 0.062 mol of Mn are substituted for the base composition of Ba3MgSi2O8.

The raw materials having the formulation shown in Table 4 were accurately weighed, thoroughly mixed in an ethanol solvent, and dried. The sufficiently mixed powder was put in an alumina container and fired at 1420 ° C. for 2 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 2.65Ba · 0.3Sr · 0.8Mg · Si 2 O 8: 0.05 Eu · 0.123 Mn.

  Afterglow luminous body 2- (1) was coarsely pulverized with an agate mortar, and the light emission characteristics were measured with a spectrofluorometer (F-4500, manufactured by Hitachi, Ltd.). FIG. 12 shows fluorescence and phosphorescence spectra. Fluorescence showed high intensity fluorescence emission peaks at 448 nm and 513 nm, and also peaks at 631 nm. Phosphorescence showed a peak at 633 nm. The fluorescent color visually observed was pinkish white and the phosphorescent color was red.

  Similarly, the substitution ratio of Eu and Mn was changed as shown in Table 5, and the afterglow phosphors 2- (2) and 2- (2) and 2- (3) was prepared and the emission characteristics were measured. The integrated values of the fluorescence and phosphorescence spectra were calculated, and the relative values when the afterglow phosphor 1- (1) is 100 are shown in Table 5.

The raw materials having the composition shown in Table 6 were accurately weighed, thoroughly mixed in an ethanol solvent, and dried. The sufficiently mixed powder was put in an alumina container, placed in a reducing atmosphere (N ₂ + H ₂ (4%)), and calcined at 1420 ° C. for 2 hours. The fired product obtained by this reaction is used as an afterglow luminous body 3- (3) . The afterglow luminous body 3- (3) is represented by 2.65Ba · 0.3CaO · 0.8Mg · Si 2 O 8: 0.0 5 Eu · 0.0123 Mn.

  Afterglow luminous body 3- (3) was coarsely pulverized with an agate mortar, and the light emission characteristics were measured with a spectrofluorimeter (F-4500, manufactured by Hitachi, Ltd.). FIG. 13 shows fluorescence and phosphorescence spectra. The fluorescence showed an emission peak at 477 nm and a peak at 624 nm. Phosphorescence showed a peak at 625 nm. The fluorescent color visually observed was pink, and the phosphorescent color was red.

  The afterglow measurement of afterglow light-emitting body 3- (3) was performed. As a result of performing afterglow measurement using an excitation light source as an LED light source having a center wavelength of 365 nm, an irradiation time of 400 ms, and a wavelength of 600 nm as a center wavelength, the afterglow time (lifetime) was 120 ms.

Similarly, the substitution ratio of Eu and Mn was changed as shown in Table 7, and the afterglow phosphor 3- (1) to 3- (3) under the same conditions as the afterglow phosphor 3- (3). 5) was prepared, and the emission characteristics were measured. The integrated values of the fluorescence and phosphorescence spectra were calculated, and the relative values when the afterglow phosphor 1- (1) is 100 are shown in Table 7.

  Next, a method for adjusting an afterglow phosphor ink composition using the afterglow phosphor of the present invention and a method for producing an authenticity printed matter will be described in Example 4. Afterglow luminescent material 1- (1) was used, and an afterglow luminescent material ink composition was prepared so as to finally have the composition shown in Table 8. First, high-concentration dispersion is performed with a three-roll mill, then the varnish is adjusted so that the blending ratios shown in Table 8 are achieved, and the mixture is stirred with a three-one motor (manufactured by Shinto Kagaku) to obtain an afterglow luminescent screen ink. A composition was prepared.

  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. 14 shows the fluorescence spectrum of the true / false discrimination printed material with excitation by 365 nm and 302 nm ultraviolet light, and the phosphorescence spectrum for 10.2 ms after 2 ms after the acquisition timing and 365 nm excitation light irradiation stop.

  Afterglow phosphor 1- (1) was used, and an afterglow phosphor flexo ink composition having the composition shown in Table 9 was produced with a planetary ball mill (manufactured by Fritsch).

  In the flexographic printing method, the number of anilox lines is 80 Line / cm, and after applying the afterglow illuminator flexographic ink composition to fine paper that is not whitened with a line drawing pattern including a solid part, ultraviolet irradiation is performed, The ink was dried to produce a true / false discrimination printed matter. The fluorescence spectrum and phosphorescence spectrum of the authenticity discrimination printed material of Example 5 were the same as the fluorescence spectrum and phosphorescence spectrum of the authenticity discrimination print material of Example 4 shown in FIG. However, in the case of the flexographic printing method, the emission intensity was relatively low due to the small amount of ink transfer.

  Afterglow phosphor 1- (1) was used, and an afterglow phosphor gravure ink composition having the composition shown in Table 10 was produced with a planetary ball mill (manufactured by Fritsch).

  Using a gravure coater, using a plate surface with a line number of 135 Line / cm, coating the non-fluorescent white coated paper with an afterglow phosphor gravure ink composition in a bar shape, and then evaporating and drying the ink. A discrimination printed matter was produced. The fluorescence spectrum and phosphorescence spectrum of the authenticity determination printed material of Example 6 were the same as the fluorescence spectrum and phosphorescence spectrum of the authenticity determination printed material of Example 4 shown in FIG. Compared with the screen print, the light emission intensity was relatively low due to the small amount of ink transfer. However, the UV varnish absorbs UV light at 254 nm, so that the emission intensity is greatly reduced by excitation at 254 nm. However, the water-soluble resin has little absorption, so that the emission intensity is hardly reduced even when the excitation light is 254 nm.

  Afterglow phosphor 1- (1) was used, and an afterglow phosphor flexo ink composition was prepared with a planetary ball mill (manufactured by Fritsch) so as to have the composition shown in Table 11.

  In the flexographic printing method, the number of anilox lines is 80 Line / cm, and after applying the afterglow illuminator flexographic ink composition to fine paper that is not whitened with a line drawing pattern including a solid part, ultraviolet irradiation is performed, The ink was dried to produce a true / false discrimination printed matter. FIG. 15 shows the fluorescence spectrum and phosphorescence spectrum of the authenticity printed matter. Since the green phosphor was mixed with the afterglow phosphor of the present invention, the peak intensity at 535 nm was increased in the fluorescence spectrum, and green fluorescence was visually observed. Since phosphorescence is red, there is a large difference between the hues of fluorescence and phosphorescence.

  Afterglow luminescent material 3- (3) was used, and a luminescent flexo ink composition was prepared with a planetary ball mill (manufactured by Fritsch) with the formulation shown in Table 12.

  In the flexographic printing method, the number of anilox lines is 40 Line / cm, after applying the afterglow illuminator flexographic ink composition to fine paper that is not fluorescent whitened with a line drawing-like pattern including a solid part, and then irradiating with ultraviolet rays, The ink was dried to produce a true / false discrimination printed matter. FIG. 16 shows fluorescence and acquisition timing of 365 nm ultraviolet light excitation of the authenticity discrimination printed matter, and a phosphorescence spectrum for 10.2 ms after 2 ms after irradiation stop.

  Next, an authentication method for authenticity printed matter using the afterglow illuminant of the present invention will be described in Example 9. The true / false discrimination printed matter of Example 4 and the authenticity discrimination print of Example 5 were irradiated with 365 nm ultraviolet light, and observed to emit yellowish white fluorescence. Next, 302 nm ultraviolet light was irradiated, and pink fluorescence was observed. It was visually confirmed that the afterglow phosphor-imparting portion instantaneously exhibited red and green light emission depending on the direction in which the ultraviolet lamp irradiating the 365 nm ultraviolet light was quickly swung left and right. That is, it was possible to observe light emission of three kinds of colors in the static and dynamic state of the light source.

  The authenticity determination printed matter of Example 6 was irradiated with ultraviolet light of 254 nm, and pink fluorescence was observed. After irradiating ultraviolet light of 254 nm for 10 s, the light was turned off, and weak green afterglow was visually recognized in the dark field.

Next, using the authenticity determination printed matter of Example 4, the determination was performed using the authenticity determination device and the determination method described in JP-A-2006-266810. The excitation light of the LED having a central wavelength of 365 nm is irradiated, and a sharp cut filter L39 and Fujifilm bandpass filters BPB-60, BPB-53 and BPB-45 are inserted on the light receiving side, and 600 nm (λ ₁ ), The light emission outputs in the three wavelength ranges with 530 nm (λ ₂ ) or 450 nm (λ ₃ ) as the center wavelength were acquired by the three light receiving sections. When the excitation light is irradiated for 400 ms and the acquisition timing is during the excitation light irradiation (T ₀ ) and after the irradiation stop 50 ms (T ₁ ), at λ ₁ , λ _2, and λ ₃ at T ₀ , 236 mV, 452 mV, and 326 mV, respectively. An output value was obtained. At T ₁ , an output value of 102 mV was obtained only for λ ₁ , and the output values at λ ₂ and λ ₃ were approximately 0V. From this result, it was confirmed that an afterglow luminescent material having three fluorescence emission peaks of λ ₁ , λ ₂ and λ ₃ and one phosphorescence peak of λ 1 was given. Next, it measured similarly using LED which set the center wavelength of the excitation light source to 430 nm. During the acquisition timing excitation light irradiation (T ₀ ), an output value of 225 mV was obtained under the light receiving condition of 530 nm (λ ₂ ). Further, it was 0 V at λ ₁ and λ ₃ .

Similarly, using the authenticity discrimination device described in Japanese Patent Application Laid-Open No. 2006-266810, the results of measuring the light emission of the authenticity discrimination printed matter of Example 5 and the authenticity discriminating printed matter of Example 8 at an excitation wavelength of 365 nm are shown. It was shown in FIG. In authenticity discrimination printed matter of Example 5, was detected light emission at T ₀ in three wavelength regions, the light emitting only lambda ₁ by T ₁ is detected. In the authenticity determination printed matter of Example 8, light emission was detected in two wavelength regions at T ₀ , and light emission was detected only at λ _{1 at} T ₁ . In determining authenticity, the allowable ranges of T ₀ λ ₁ , T ₀ λ ₂ , T ₀ λ ₃ , T ₁ λ ₁ , T ₁ λ _2, and T ₁ λ ₃ are determined, and all measured values are within that range. Authenticate when entering.

(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 15 were accurately weighed, thoroughly mixed in an ethanol solvent, and dried. The sufficiently mixed powder was put in an alumina container and fired at 1420 ° C. for 2 hours in a reducing atmosphere (N ₂ + H _{2 (} 4%)). The luminous body of Comparative Example 1 mainly contains a compound represented by 2.95Ba · 0.4Mg · Si 2 O 8: 0.05Eu · 0.062 Mn.

  The phosphor of Comparative Example 1 was coarsely pulverized with an agate mortar, and the emission characteristics were measured with a spectrofluorometer (F-4500, manufactured by Hitachi, Ltd.). FIG. 17 shows fluorescence and phosphorescence spectra. In excitation with 365 nm, fluorescence showed a peak at 513 nm, and phosphorescence showed very little light emission with no emission peak detected as shown in FIG. In visual observation, green fluorescence was observed, and phosphorescence could not be visually recognized.

(Comparative Example 2)
Using a blue phosphor, a green phosphor, and a red phosphor, a light-emitting flexo ink was produced with a planetary ball mill (manufactured by Fritsch) with the formulation shown in Table 15.

  Flexographic printing method with anilox line number of 40 Line / cm, light-emitting flexo ink applied to high-quality paper that is not whitened with a line drawing-like pattern including a solid part, then irradiated with ultraviolet light, dried and compared The printed material of Example 2 was produced. FIG. 18 shows the fluorescence and acquisition timing of the printed matter of Comparative Example 2 excited by ultraviolet light at 365 nm, and the phosphorescence spectrum for 10.2 ms after 2 ms from the stop of irradiation.

  The printed matter of Comparative Example 2 was irradiated with 365 nm ultraviolet light, and yellowish white fluorescence was observed. Next, the comparative printed matter was observed while quickly swinging the ultraviolet lamp irradiating ultraviolet light of 365 nm to the left and right. Under dynamic irradiation conditions, it was impossible to visually recognize a change in emission color.

The printed matter of Comparative Example 2 was determined using the authenticity determination device and the determination method described in Japanese Patent Application Laid-Open No. 2006-266810. Excitation light of an LED having a central wavelength of 365 nm is irradiated, and a sharp cut filter L39 and bandpass filters BPB-60, BPB-53 and BPB-45 made by Fuji Film are inserted on the light receiving side, and 600 nm (λ ₁ ) Light emission outputs in three wavelength regions having a central wavelength of 530 nm (λ ₂ ) or 450 nm (λ ₃ ) were acquired by three light receiving units. When the excitation light is irradiated for 400 ms, and the acquisition timing is during excitation light irradiation (T ₀ ) and after irradiation stop 50 ms (T ₁ ), at T ₀ , λ ₁ , λ _2, and λ ₃ are 600 mV, 600 mV, and 500 mV, respectively. A value was obtained, and at T ₁ , the output values at λ ₁ , λ ₂ and λ ₃ were 0V. Next, it measured similarly using LED which set the center wavelength of the excitation light source to 430 nm. During the acquisition timing excitation light irradiation (T ₀ ), no output value was obtained under the light receiving condition of 530 nm (λ ₂ ).

  In the printed matter of Comparative Example 2, phosphorescence was not detected both visually and by machine detection. Therefore, it was found that there were fewer judgment elements at the time of discrimination than the true / false discrimination printed matter of Examples 4 to 8. Therefore, it can be said that the printed matter of Comparative Example 2 has lower authenticity and discrimination accuracy than the authenticity discrimination printed matter of the example.

Claims (11)

The following chemical formula:
  (M _k Ba _a-x Eu _x ) (A + k) O. (Mg _by Mn _y BO · c (SiO ₂ )
Indicated by
In the formula, M is an alkaline earth metal Ca (calcium), Sr (strontium),
  k is 0 or 0.3;
  a is 2 ≦ a ≦ 3.5,
  b is 0.75 ≦ b ≦ 2,
  c is 1.5 <c ≦ 3,
  x is 0.01 ≦ x ≦ 0.2,
  y is an afterglow illuminant where 0.02 ≦ y ≦ 0.4;
  An afterglow luminescent material comprising a mixed phase of a plurality of crystal phases containing the chemical formula,
  The afterglow illuminant is a yellowish white or pinkish white or pink fluorescent color when irradiated with excitation light,
  The phosphorescent color after stopping the excitation light is red,
  The afterglow time after the excitation light is stopped is 2 ms to 5 s.
Chemical formula Ba, Mg and SiO ₂ A blending step of blending a matrix material containing each of the raw materials of the activator being Eu and Mn,
  A mixing step of mixing the blended raw materials;
A baking step of baking the mixture dried after the mixing step in a reducing atmosphere at a baking temperature of 1200 ° C. to 1480 ° C. for 0.5 hour to 5 hours;
A method for producing an afterglow luminescent material, comprising a post-treatment step of washing, pulverizing and classifying the mixture after the firing step. The following chemical formula:
  (M _k Ba _a-x Eu _x ) (A + k) O. (Mg _by Mn _y BO · c (SiO ₂ )
Indicated by
In the formula, M is an alkaline earth metal Ca (calcium), Sr (strontium),
  k is 0 or 0.3;
  a is 2 ≦ a ≦ 3.5,
  b is 0.75 ≦ b ≦ 2,
  c is 1.5 <c ≦ 3,
  x is 0.01 ≦ x ≦ 0.2,
  y is an afterglow illuminant where 0.02 ≦ y ≦ 0.4;
  An afterglow luminescent material comprising a mixed phase of a plurality of crystal phases containing the chemical formula,
  The afterglow illuminant is a yellowish white or pinkish white or pink fluorescent color when irradiated with excitation light,
  The phosphorescent color after stopping the excitation light is red,
  An afterglow luminescent ink composition comprising an afterglow luminescent material having an afterglow time of 2 ms to 5 s after the excitation light is stopped, and a varnish mixed therein. The following chemical formula:
  (M _k Ba _a-x Eu _x ) (A + k) O. (Mg _by Mn _y BO · c (SiO ₂ )
Indicated by
In the formula, M is an alkaline earth metal Ca (calcium), Sr (strontium),
  k is 0 or 0.3;
  a is 2 ≦ a ≦ 3.5,
  b is 0.75 ≦ b ≦ 2,
  c is 1.5 <c ≦ 3,
  x is 0.01 ≦ x ≦ 0.2,
  y is an afterglow illuminant where 0.02 ≦ y ≦ 0.4;
  An afterglow luminescent material comprising a mixed phase of a plurality of crystal phases containing the chemical formula,
  The afterglow illuminant is a yellowish white or pinkish white or pink fluorescent color when irradiated with excitation light,
  The phosphorescent color after stopping the excitation light is red,
  Use of an afterglow illuminant having an afterglow time of 2 ms to 5 s after stopping the excitation light as a paint or ink. The following chemical formula:
  (M _k Ba _a-x Eu _x ) (A + k) O. (Mg _by Mn _y BO · c (SiO ₂ )
Indicated by
In the formula, M is an alkaline earth metal Ca (calcium), Sr (strontium),
  k is 0 or 0.3;
  a is 2 ≦ a ≦ 3.5,
  b is 0.75 ≦ b ≦ 2,
  c is 1.5 <c ≦ 3,
  x is 0.01 ≦ x ≦ 0.2,
  y is an afterglow illuminant where 0.02 ≦ y ≦ 0.4;
  An afterglow luminescent material comprising a mixed phase of a plurality of crystal phases containing the chemical formula,
  The afterglow illuminant is a yellowish white or pinkish white or pink fluorescent color when irradiated with excitation light,
  The phosphorescent color after stopping the excitation light is red,
  An authenticity printed matter having an area including an afterglow illuminant having an afterglow time of 2 ms to 5 s after stopping the excitation light, on at least a part of the substrate,
  The region including the afterglow illuminant in the authenticity determination printed matter is characterized in that the authenticity is determined by a difference in emission color when the excitation light is irradiated and emission color of the afterglow when the excitation light is stopped. True / false discrimination printed matter. The following chemical formula:
  (M _k Ba _a-x Eu _x ) (A + k) O. (Mg _by Mn _y BO · c (SiO ₂ )
Indicated by
In the formula, M is an alkaline earth metal Ca (calcium), Sr (strontium),
  k is 0 or 0.3;
  a is 2 ≦ a ≦ 3.5,
  b is 0.75 ≦ b ≦ 2,
  c is 1.5 <c ≦ 3,
  x is 0.01 ≦ x ≦ 0.2,
  y is an afterglow illuminant where 0.02 ≦ y ≦ 0.4;
  An afterglow luminescent material comprising a mixed phase of a plurality of crystal phases containing the chemical formula,
  The afterglow illuminant is a yellowish white or pinkish white or pink fluorescent color when irradiated with excitation light,
  The phosphorescent color after stopping the excitation light is red,
  In the afterglow light emitter whose afterglow time after stopping the excitation light is 2 ms to 5 s,
The afterglow illuminant has a peak wavelength centered around at least 620 nm, and the afterglow time is 10 ms to 1 s. The following chemical formula:
  (M _k Ba _a-x Eu _x ) (A + k) O. (Mg _by Mn _y BO · c (SiO ₂ )
Indicated by
In the formula, M is an alkaline earth metal Ca (calcium), Sr (strontium),
  k is 0 or 0.3;
  a is 2 ≦ a ≦ 3.5,
  b is 0.75 ≦ b ≦ 2,
  c is 1.5 <c ≦ 3,
  x is 0.01 ≦ x ≦ 0.2,
  y is an afterglow illuminant where 0.02 ≦ y ≦ 0.4;
  An afterglow luminescent material comprising a mixed phase of a plurality of crystal phases containing the chemical formula,
  The afterglow illuminant is a yellowish white or pinkish white or pink fluorescent color when irradiated with excitation light,
  The phosphorescent color after stopping the excitation light is red,
  The afterglow time after stopping the excitation light is 2 ms to 5 s,
  a = 3,
  b = 1,
  c = 2,
  0.05 ≦ x ≦ 0.1,
  An afterglow light-emitting body, wherein 0.05 ≦ y ≦ 0.25.   The afterglow light emission according to claim 6, wherein the afterglow wavelength in the afterglow light emitter has a peak wavelength centered at least at 620 nm, and the afterglow time is 10 ms to 1 s. body. An afterglow luminescent ink composition comprising the afterglow luminescent material according to any one of claims 5 to 7 and a varnish. Use of the afterglow illuminant according to any one of claims 5 to 7 as a paint or ink. The authenticity discrimination printed matter having a region containing the afterglow illuminator according to any one of claims 5 to 7 on at least a part of a substrate,
  The region including the afterglow illuminant in the authenticity determination printed matter is characterized in that the authenticity is determined by a difference in emission color when the excitation light is irradiated and emission color of the afterglow when the excitation light is stopped. True / false discrimination printed matter.   The method for producing an afterglow light emitter according to any one of claims 5 to 7, wherein the chemical formula Ba, Mg, and SiO ₂ A blending step of blending a matrix material containing each of the raw materials of the activator being Eu and Mn,
  A mixing step of mixing the blended raw materials;
A baking step of baking the mixture dried after the mixing step in a reducing atmosphere at a baking temperature of 1200 ° C. to 1480 ° C. for 0.5 hour to 5 hours;
A method for producing an afterglow luminescent material, comprising a post-treatment step of washing, pulverizing and classifying the mixture after the firing step.

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