JP6520927B2 - Luminescent paper, anti-counterfeit medium and packaging container - Google Patents

Description

  Embodiments of the present invention relate to luminescent paper, anti-counterfeit media and packaging containers.

  The stress luminescent material which emits light due to stress has been variously developed for practical use (see Patent Documents 1 and 2). In particular, application of the stress-luminescent material to anti-counterfeit media such as banknotes and securities which are required to prevent forgery is under consideration.

  In addition, in the United States, it is planned that the provision of anti-counterfeit functions in drug packages be legalized, and similar functions may be legalized in other countries.

JP 2007-55144 A Unexamined-Japanese-Patent No. 2003-253261

  Aside from public anti-counterfeit media such as banknotes, it is desirable to be able to correctly determine authenticity at as low cost as possible when providing paper sheets used in the private sector with anti-counterfeit functions.

  When producing paper containing stress luminescent material, it is necessary to mix the stress luminescent material into the paper pulp fiber, but even if the stress luminescent material emits light due to stress, the luminous intensity of the paper is It may be weak. In addition, the stress light emitting material needs to store light energy from the outside before light emission due to stress. Also in this case, if there are paper pulp fibers around the stress luminescent material, sufficient light energy may not be accumulated in the stress luminescent material. When the stored light energy is low, the light emission intensity of the stress light emitting material is weakened.

  Further, from the viewpoint of preventing forgery, it is desirable that the paper does not visually indicate that the stress light emitting material is contained.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a light-emitting sheet, a forgery-preventing medium, and a packaging container which have high light-emitting intensity and which do not cause an unpleasant appearance.

According to an embodiment of the present invention, comprising paper pulp fibers and stress luminescent material,
The paper pulp fibers and the stress-stimulated luminescent material are arranged to be in contact at least in part,
The stress light emitting material is provided with a light emitting paper which emits light of a predetermined wavelength with a light emission intensity corresponding to the deformation stress when a deformation stress which deforms the paper pulp fiber is generated by an external load.

The light emitting paper may have at least two areas where the density of the paper pulp fibers is different,
Of the two regions, the region with the lower density of the paper pulp fibers emits light at a higher emission intensity for the same deformation stress as compared with the region with the higher density of the paper pulp fibers. Good.

  The external shape of the area where the density of the paper pulp fibers is lower may be a shape that represents arbitrary information.

In a part of the surface of the light emitting paper, a region to which visible light transmitting ink for suppressing irregular reflection of the surface is attached may be provided.
The region may emit light with higher emission intensity to the same deformation stress as compared to the other surfaces.

The light-emitting sheet may be provided with at least two regions having different sheet thicknesses.
Of the two regions, a region with a thinner paper thickness may emit light with higher emission intensity for the same deformation stress as compared with a region with a thicker paper thickness.

  The outer shape of the area with the thinner paper thickness may be a shape that represents arbitrary information.

  The light-emitting sheet may include a first region not including the stress light-emitting material but including the paper pulp fibers, and a second region including the stress light-emitting material and the paper pulp fibers.

  The paper thickness of the first area may be larger than the paper thickness of the second area.

  The outer shape of the second region may be a shape representing arbitrary information.

Containing sizing agents,
The color difference between the color tone of the sizing agent and the color tone of the stress-stimulated luminescent material may be 0.5 or less.

  The stress-stimulated luminescent material has a needle-like or strip-like shape, has a length of 1/10 to 1/2 of the paper pulp fibers, and is disposed to intersect with the paper pulp fibers. Good.

  The stress luminescent material may be laminated to the paper pulp fibers.

  The stress luminescent material may coat the paper pulp fibers.

  The stress-stimulated luminescent material may have a portion where the stress concentration factor α is 2 or more with respect to the external load on the luminescent sheet.

Another aspect of the invention is a forgery resistant medium comprising paper pulp fibers and a stress luminescent material,
The anti-counterfeit medium comprises at least two areas,
The stress light-emitting material emits light with higher emission intensity to the same deformation stress in one of the two regions than the other in one of the two regions when a deformation stress that deforms the paper pulp fiber is generated by an external load. An anti-counterfeit medium is provided.

Another aspect of the invention is a packaging container comprising paper pulp fibers and a stress luminescent material, the packaging container comprising:
Equipped with perforations or sealing members for opening;
The stress-stimulated luminescent material in the perforations or the seal member is deformed when the perforations are broken or a deformation stress that deforms the paper pulp fibers is generated due to an external load when peeling the seal member. A packaging container is provided which emits light with an emission intensity corresponding to a stress.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing of the light emission paper 1 by the 1st Embodiment of this invention. FIG. 2 is a process diagram showing a papermaking process of the light-emitting paper 1 according to the first embodiment. Sectional drawing of the light emission paper 1 by the 2nd Embodiment of this invention. Sectional drawing of the light emission paper 1 by the 3rd Embodiment of this invention. FIG. 13 is a process chart showing the papermaking process of the luminescent paper 1 according to the third embodiment. The figure explaining a 1st method. The figure explaining a 1st method. The top view of the paper pulp fiber 2 which printed watermark ink. 7A is a cross-sectional view taken along line A-A of FIG. 7A. The top view at the time of forming a recessed part in a paper pulp fiber layer. The AA sectional view taken on the line of FIG. 8A. The top view which formed the opening in the place which stuck the tape. FIG. 9B is a plan view showing a process following FIG. 9A. The top view which shows the process of following FIG. 9B. The top view which shows the process of following FIG. 9C. The figure which shows an example of a packaging container.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1 is a cross-sectional view of a light-emitting paper 1 according to a first embodiment of the present invention. The light emitting paper 1 of FIG. 1 contains a paper pulp fiber 2 and a stress light emitting material 3. More specifically, the stress-stimulated luminescent material 3 has a needle-like or band-like shape. Below, the stress luminescent material 3 which has such a shape is called the ML fiber 5. FIG. ML is an abbreviation of mechanical luminescence (Mechanical Luminescence).

  The ML fibers 5 typically have a length of 1/10 to 1/2 of the paper pulp fibers 2. In the case of softwood pulp fibers typical as the paper pulp fibers 2, they have a length of 1.0 to 6.0 mm, and the length of the ML fibers 5 is about 0.1 mm to 3.0 mm.

  The ML fiber 5 contains, for example, strontium aluminate to which europium is added as a luminescent center, and in this case, it emits green light due to stress. Alternatively, it contains zinc sulfide added with manganese as a luminescent center, and in this case, yellow orange light is emitted due to stress.

  As shown in FIG. 1, at least a part of the paper pulp fibers 2 and the ML fibers 5 are in contact with each other in the light emitting paper 1. In FIG. 1, the contact portion between the paper pulp fiber 2 and the ML fiber 5 is indicated by reference numeral 4. The external force load applied to the light emitting paper 1 is transmitted to the paper pulp fibers 2 in the light emitting paper 1, and the paper pulp fibers 2 are deformed by being pulled or bent each other. When the paper pulp fiber 2 is deformed, the ML fiber 5 in contact with the paper pulp fiber 2 is also deformed, and the ML fiber 5 emits light of a predetermined wavelength with a luminous intensity corresponding to the deformation stress.

  Generally, as the lengths of the pulp and paper fibers 2 and the ML fibers 5 are longer, they are more likely to cross or entangle and be more susceptible to stress. Further, as the paper pulp fiber 2 is longer, light due to stress is more likely to propagate in the longitudinal direction of the paper pulp fiber 2, so that the light intensity is higher, but the light intensity in the short direction is weaker. On the contrary, when the paper pulp fibers 2 are short, the difference in light intensity between the longitudinal direction and the short direction of the paper pulp fibers 2 becomes small.

  FIG. 2 is a process diagram showing the papermaking process of the light-emitting paper 1 according to the first embodiment. First, a pulping process is performed (step S1). In this process, for example, bark is removed from wood and crushed into chips, and high temperature heat treatment is performed in an aqueous solution of sodium hydroxide or sodium chloride to chemically pulp wood.

  Next, a pulp bleaching step is performed (step S2). In this step, the pulp prepared in step S1 is bleached with a bleaching agent such as chlorine dioxide.

  Next, the pulp selection and dewatering process is performed (step S3). In this step, undigested fibers and dust contained in the pulp are removed by a cleaner or the like and then dewatered to form a pulp sheet.

  Next, melting and beating are performed as a first raw material adjusting step (step S4). In this process, the pulp sheet is melted again into water using a pulper or the like, and the pulp melt is passed between the two metal blades in a state where the pulp is uniformly mixed with a sufficient amount of water. For example, cut the pulp to an appropriate size, fluff it (fibrillation), and make it easy to connect the fibers.

  Through the steps S1 to S4 described above, a suspension containing the paper pulp fibers 2 is obtained.

  Next, in the second raw material adjusting step, the stress light emitting material 3 and the sizing agent are added to the suspension containing the paper pulp fiber 2 (step S5).

  The ratio of the stress luminescent material 3 to the paper pulp fiber 2 is, for example, 10 to 300% with respect to 100% of the paper pulp fiber 2, and the specific ratio is set according to the purpose of use of the light emitting paper 1 of the present invention . If the ratio of the stress light emitting material 3 is less than 10%, sufficient light emission for visual recognition can not be obtained when the predetermined external load is applied to the light emitting paper 1, and if it exceeds 300%, the rigidity of the light emitting paper 1 Is too strong, or the specific gravity of the light emitting paper 1 is too large.

  Of course, the stress light emitting material 3 may be included at a ratio of 300% or more for use in which the rigidity of the light emitting paper 1 is increased intentionally, but the deformation pressure transmitted to the paper pulp fiber 2 is a stress light emitting material The efficiency of transmission to 3 is reduced.

  The stress light emitting material 3 has, for example, a basic structure in which an alkali metal ion and / or an alkaline earth metal ion is inserted in a space of a host crystal formed by a plurality of molecules of a polyhedral structure. Good. As a light emission center of the stress light emitting material 3, rare earth metal ions such as europium (Eu) can be used. In addition, the stress light-emitting material 3 should just be a material light-emitted by stress, and the specific material is not limited to what was mentioned above.

  The stress concentration factor of the stress-stimulated luminescent material 3 is preferably as large as possible, and is preferably at least two or more. In order to make the stress concentration factor of the “stress light emitting material” be 2 or more, for example, a recess or a cut having a depth of 1/10 to 1/5 of its diameter in a part of the stress light emitting material having a fiber shape It is obtained by providing a notch.

  Moreover, in order to improve the water resistance of the stress light emitting material 3, it is also preferable to apply a surface treatment to the stress light emitting material 3. In this surface treatment, an appropriate amount of the surface treatment agent is dissolved in an appropriate organic solvent (organic solvent) at room temperature or by heating, and the solution is subjected to an appropriate amount of the above according to the purpose. The stress-stimulated luminescent material 3 is added, and after stirring for an appropriate period of time using an appropriate stirring device such as a dissolver or a mixer, the resultant is obtained by drying under appropriate conditions. At this time, it is necessary to set conditions so as to maintain the shape of the stress light emitting material 3 without breaking it. Further, it is more preferable to adjust the water content of the organic solvent, and the water content is less than 0.5%. When the water content is 0.5% or more, the light emission characteristics of the stress-stimulated luminescent material 3 are degraded by the water in the solution.

  Furthermore, in order to further improve the water resistance, it is also preferable to cover the surface of the stress-stimulated luminescent material 3 to be added to the above-described solution in advance with a waterproof silica layer or the like. The thickness of this film is set to be 0.1 μm to 10 μm.

  The sizing agent is used to improve the printability as a paper, smoothness, abrasion resistance, barrier property, folding strength, burst strength, oil resistance, chemical resistance, etc. at the stage of making the light-emitting paper 1 Is a generic term for materials used for Sizing agents include retention agents, drainage improvers, paper strength agents, thickeners, sizing agents, bulking agents, fillers, and coating chemicals. Among them, the sizing agent is a material that suppresses the penetration of the ink solvent into the paper when the printing ink is attached to the paper, prevents the offset and the bleeding, and gives a certain degree of water resistance. The filler is a mineral powder formulated or applied to make the paper opaque to prevent strike-through, or to have whiteness and smoothness.

  In the process of step S5 described above, various sizing agents such as a sizing agent and a filler are added in appropriate amounts according to the application of the light-emitting paper 1.

  Since the sizing agent affects the color tone of the light emitting paper 1, the color difference between the color tone of the sizing agent and the color tone of the stress light emitting material 3 is, for example, 0.5 or less. 3 becomes inconspicuous.

  By the process of step S5 of FIG. 2 mentioned above, the pulp suspension containing paper pulp fiber 2, a stress generating material, a sizing agent, etc. is obtained. Next, as the first paper making process, a wiring and water squeezing process is performed (step S6). Thereby, a wet paper containing water is obtained. In this step, the above-described pulp suspension is applied at a predetermined concentration and speed onto a belt-like continuous meshed wire (wire) made of PET (polyethylene terephthalate) fiber or bronze fiber, etc. And at an angle, the film is uniformly supplied in the width direction of the net to form a coating of a predetermined thickness on the wire. Next, water is squeezed on the wire to form a wet paper for the light emitting paper 1. As described later, when the light-emitting paper 1 is to be watermarked, the uneven roller is pressed against the wet paper, and the fiber of the portion pressed by the convex part of the roller is released to the periphery, thereby the surface of the wet paper. Make the surface uneven.

  Next, drying and pressing are performed as a second paper making process (step S7). In this process, the wet paper web is peeled off from the wire and moved to a felt, and pressure is applied with a few rolls using a press machine to perform a roll press process to further squeeze water. Thereby, a high density wet paper can be obtained.

  Thereafter, the wet paper web is moved while being wound around a number of cylinder drums heated by steam and dried.

  Finally, a processing and finishing process is performed (step S8). In this process, depending on the application of the light-emitting paper 1, a size press process, a coating process such as glossing, a calendar process, etc. are performed. The coating process and the calendering process may be performed by another dedicated device.

  The light-emitting paper 1 according to the embodiment of the present invention produced by the above-described process can be produced by a manual making method, but for mass production, a paper machine capable of carrying out the papermaking process shown in FIG. Paper machines of each type such as twin wire type, gap former type, circular net type, and Yankee type are used. You can also add a machine calendar processor.

  The thickness and size of the light-emitting paper 1 according to the embodiment of the present invention are arbitrary, the thickness is, for example, 5 μm to 500 μm, and the size is an arbitrary size such as A series or B series.

  As described above, in the light emitting paper 1 according to the first embodiment, since the paper pulp fiber 2 and the ML fiber 5 made of the stress light emitting material 3 are arranged to be in contact at least in part, When an external load is applied, both the paper pulp fiber 2 and the ML fiber 5 are deformed by an external force, and the ML fiber 5 made of the stress light emitting material 3 emits light of a predetermined wavelength with a light emission intensity corresponding to the deformation stress. .

Second Embodiment
In the second embodiment, the stress light emitting material 3 is formed into fine particles and laminated on the paper pulp fibers 2.

  FIG. 3 is a cross-sectional view of a light-emitting paper 1 according to a second embodiment of the present invention. The light emitting paper 1 of FIG. 3 has the fine particles of the sizing agent 6 laminated on the paper pulp fibers 2 and the fine particles of the stress light emitting material 3 laminated on the paper pulp fibers 2 as well. Hereinafter, the particles of the stress light emitting material 3 are referred to as ML particles 7.

Specific materials of the stress luminescent material 3 and the sizing agent 6 are the same as in the first embodiment. The ML fine particles 7 made of the stress luminescent material 3 have a maximum diameter of 0.1 μm to 50 μm, preferably 5.0 μm to 20 μm. Alternatively, the ML fine particles 7 have an average particle diameter D ₅₀ of 0.05 μm to 20 μm, preferably 0.5 μm to 10 μm. The ML fine particles 7 are, for example, physically crushed and pulverized into a flat plate or a lump of the stress light emitting material 3.

  The luminescent paper 1 according to the second embodiment is manufactured in the same process as that of FIG. However, the contents of the second raw material adjusting step of step S5 are different from those of the first embodiment.

  In the simplest laminating method of laminating fine particles of the stress light emitting material 3 on the paper pulp fibers 2, the stress light emitting material 3 having the above-described predetermined shape is placed on the reticulated paper pulp fibers 2 in step S5 of FIG. A spray solution dispersed in liquefied petroleum gas (stress light emitting material 3 / liquefied petroleum gas weight ratio is 10/100 to 50/100), and the spray solution is sprayed using an electric spray or an air spray to apply stress. The light emitting material 3 is attached to the surface (front and / or back, the same shall apply hereinafter) of the paper pulp fiber 2.

  Surface treatment with fine particles (average particle diameter D50, 0.05 to 5.0 μm) of the stress light emitting material 3, further, an appropriate surfactant or the like to make it easy to float in a spray solution, paper pulp fibers It is also possible to use a stronger bond at the two contact surfaces.

  In any case, the ratio of the weight of the stress-stimulated luminescent material 3 attached to at least the weight of the paper pulp fiber 2 is 100/1 to 100/30, preferably 100/5 to 100/10. .

  As another lamination method, the above-mentioned reticulated paper pulp fiber 2 is once dried and dipped in an immersion solution (dipping solution) prepared in advance, and the immersion solution is applied to the surface of reticulated paper pulp fiber 2 Adhere and dry. At this time, as the immersion solution (dipping solution), a transparent resin containing the stress-luminescent material 3 having a predetermined shape dispersed therein, and further, a transparent resin containing fine particles containing the stress-luminescent material 3 as the composition Can be used by dissolving it in an appropriate solvent to give appropriate fluidity.

  Here, a transparent resin is a resin having a high visible light transmittance, and for example, the transmittance of sodium atom at D line (590 nm) is 50% or more, preferably 80% or more.

  The ML fine particles 7 are dispersed in a transparent resin, and a predetermined solvent is further added to adjust the fluidity. Under the present circumstances, in order to suppress the penetration to a paper pulse fiber, it is considered as a comparatively high viscosity.

  Alternatively, instead of laminating a thin film of a transparent resin in which the ML fine particles 7 are dispersed on the surface of the paper pulp fiber 2, the reticulated paper pulp fiber 2 is once dried, and the ink composition containing the ML fine particles 7 on the surface The object may be printed or coated.

  Also in the second embodiment, as in the first embodiment, the process of improving the water resistance of the stress-stimulated luminescent material 3 is performed as necessary.

  As described above, in the second embodiment, since the particulate stress light emitting material 3 is laminated on the paper pulp fibers 2, the stress light emitting material 3 can be uniformly dispersed in the entire area of the light emitting paper 1. Even when an external load is applied to any part of the light emitting element, light emission can be performed according to the deformation stress.

Third Embodiment
In the third embodiment, the paper pulp fibers 2 are coated with a stress luminescent material 3.

  FIG. 4 is a cross-sectional view of a light-emitting paper 1 according to a third embodiment of the present invention. In the light emitting paper 1 of FIG. 4, the stress light emitting material 3 covers the surface of the paper pulp fiber 2. Hereinafter, the paper pulp fibers 2 coated with the stress luminescent material 3 will be referred to as ML coated paper pulp fibers 8. As shown in FIG. 4, the ML-coated paper pulp fibers 8 cross each other, and more preferably are entangled. Therefore, when an external load is applied to the light-emitting paper 1, the ML-coated paper pulp fibers 8 are deformed, and the ML-coated paper pulp fibers 8 emit light with a luminous intensity corresponding to the deformation stress.

  FIG. 5 is a process diagram showing the papermaking process of the light-emitting paper 1 according to the third embodiment. As for FIG. 5, the coating process of the stress luminescent material 3 is provided between step S4 of FIG. 2, and S5 (step S9). In step S9, the ML coated paper pulp fiber 8 is produced using the fine particles of the stress luminescent material 3 or the fine particles having the stress luminescent material 3 as a composition. At that time, fine particles of the stress light emitting material 3 or fine particles having the composition of the stress light emitting material 3 or these fine particles were dispersed in a transparent resin using a spray method, dipping method, printing method or coating method And coat the paper pulp fibers 2.

  As the simplest coating method, fine particles (average particle diameter D50, 0.05 to 5.0 μm) of stress luminescent material 3 on paper pulp fibers 2 prepared in advance are liquefied petroleum gas (liquefied propane gas Or spray solution dispersed in dimethyl ethane) (weight ratio of particulates / liquefied petroleum gas is 10/100 to 50/100), and spray the spray solution using an electric spray or an air spray. Fine particles of the stress luminescent material 3 are attached to the surface of the paper pulp fiber 2 to form ML coated paper pulp fiber 8.

  As the paper pulp fibers 2, the state of the paper pulp fibers 2 at the stage after the first raw material adjustment step in the paper making process shown in FIG. 5, that is, the thickness and length of each paper pulp fiber 2 are determined A state in which they contain a large amount of water and are called a wet paper, or a state in which the wet paper is once dried and in a so-called mesh shape is used. Both are mesh-like and sheet-like paper pulp fibers 2 (hereinafter referred to as reticulated paper pulp fibers 2). At this time, it is also preferable to surface-treat the fine particles of the stress light-emitting material 3 with an appropriate surfactant or the like to make it easy to float in the spray solution or to make it easy to adhere to the surface of the paper pulp fiber 2.

  The spray solution may be sprayed onto the entire surface of the paper pulp fibers 2 or a portion thereof, but at least particles of the stress-stimulated luminescent material 3 attached to the weight of the paper pulp fibers 2 The weight ratio of 100/5 to 100/20.

  Then, when the ML-coated paper pulp fibers 8 cross each other, the fine particles of the stress light-emitting material 3 on the outermost surface of these portions in the intersecting portion (predetermined portion) mutually strengthen the deformation stress. It will emit light strongly.

  As another coating method, the above-mentioned reticulated paper pulp fiber 2 is once dried and dipped in an immersion solution (dipping solution) prepared in advance, and the immersion solution is applied to the surface of reticulated paper pulp fiber 2 Deposit and dry to make ML coated paper pulp fibers 8.

  As an immersion solution (dipping solution) at this time, fine particles (average particle diameter D50, 0.05 to 5.0 .mu.m) of the stress light emitting material 3 are made of a predetermined solvent, that is, higher alcohol, toluene, xylene, cyclohexanone, etc. , Boiling point is as high as 100 degrees or more, and the weight ratio of particles / solvent to 10/100 to 50/100 is a solvent (meaning that the normal temperature vapor pressure is very small) or non-volatile solvent It is possible to use a thing or a transparent resin in which fine particles having the composition of the stress light emitting material 3 dispersed are dissolved in an appropriate solvent to give fluidity.

  As described above, in the third embodiment, since the paper pulp fibers 2 are coated with the stress light emitting material 3, when the paper pulp fibers 2 are deformed when an external load is applied to the light emitting paper 1, the stress light emission is matched accordingly. The material 3 also becomes deformed, and the entire paper pulp fiber 2 can be evenly lit.

Fourth Embodiment
The stress light emitting material 3 emits light when stressed using the stored light energy. Therefore, in order to improve the light emission intensity of the stress light emitting material 3, it is necessary to irradiate the light having a sufficient light amount to the stress light emitting material 3 in advance to store the light energy. In order to improve the luminous performance of the stress light emitting material 3 contained in the light emitting paper 1, it is necessary to increase the transmittance of the light emitting paper 1. When the transmittance of the light emitting paper 1 is increased, the amount of light reaching the inside of the light emitting paper 1 is increased, and the accumulated light amount of the stress light emitting material 3 is increased.

  As a method of improving the transmittance of the light emitting paper 1, it is effective to put a watermark on a part of the light emitting paper 1. The area of the light-emitting paper 1 containing the watermark (hereinafter referred to as a watermark area) has a density of the paper pulp fibers 2 smaller than that of the area not containing the watermark. That is, since the amount of paper pulp fibers 2 per unit area is small in the watermark area, the external light is easily transmitted, the external light easily reaches the stress light emitting material 3 in the watermark area, and the area in which the watermark is not entered Rather, the luminous capacity of the stress light emitting material 3 is improved. Thus, the stress-stimulated luminescent material 3 in the watermark region can obtain higher emission intensity than the stress-stimulated luminescent material 3 in the region not having the watermark.

  In addition, when the stress light emitting material 3 in the watermark area emits light when an external load is applied to the light emitting paper 1, the density of the paper pulp fiber 2 is small, and thus the emitted light is less likely to be blocked by the paper pulp fiber 2. The ratio of light reaching the surface of the light-emitting paper 1 is increased, and the image is viewed more brightly.

  As described above, when the light emitting paper 1 is partially watermarked, the stress light emitting material 3 in the watermark region emits light brighter than the stress light emitting material 3 in the region not having the watermark.

  A plurality of methods can be considered as a method of putting a watermark on the light emitting paper 1. Hereinafter, representative first to fourth methods will be described in order.

  6A and 6B illustrate the first method. In the first method, as shown in FIG. 6A, when a roller having irregularities formed on the roller surface is pressed against the wetted pulp fiber 2, the fiber of the portion pressed by the convex portion of the roller is around the convex portion. The relief 11 is formed on the surface of the paper pulp fiber 2. In addition, the stress luminescent material 3 is previously contained in the paper pulp fiber 2. The shape of the unevenness 11 formed on the surface of the paper pulp fiber 2 may represent some information such as numbers, symbols, and images. Arbitrary information can be transferred to the surface of the paper pulp fiber 2 by forming irregularities on the roller surface in advance according to the contents of the information.

  Next, as shown in FIG. 6B, the uneven surface of the paper pulp fiber 2 is pressed from above to flatten it, whereby the density of the paper pulp fiber 2 becomes higher in the region 12 which was a convex part. That is, in the area 12 which is the convex portion, the density of the paper pulp fibers 2 is higher than in the area 13 which is the concave portion. Thus, high density area 12 and low density area 13 can be simultaneously formed on the sheet of paper pulp fibers 2. Among these, the low density area 13 which was initially a concave portion can be used as a watermark area because the density of the paper pulp fibers 2 is low and the transmittance is high.

  7A and 7B illustrate the second method. In the second method, an arbitrary area on the surface of the paper pulp fiber 2 including the stress luminescent material 3 is set as a watermark area, and the watermark ink 14 is printed on the watermark area. FIG. 7A is a plan view of the paper pulp fiber 2 on which the watermark ink 14 is printed, and FIG. 7B is a sectional view taken along the line AA of FIG. 7A. The watermark ink 14 is an ink that is transparent, that is, has visible light transparency, and has the function of eliminating the micro unevenness formed on the surface of the paper pulp fiber 2 to make it flat. As a result, the irregular reflection on the surface of the paper pulp fiber 2 is less likely to occur, and the area printed with the watermark ink 14 has an improved transmittance and can be seen as a watermark.

  Therefore, the area in which the watermark ink 14 is printed improves the transmittance of external light more than the other areas, and can improve the luminous performance of the stress light emitting material 3 and increase the light emission intensity of the stress light emitting material 3 can do.

  In addition, since the watermark ink 14 can be printed at any place on the surface of the paper pulp fiber 2 as in the case of the ordinary ink, it is more free than the first example described above in terms of the location, shape and size of the watermark area. The degree is higher. Further, since the watermark ink 14 can print arbitrary information, the arbitrary light can be illuminated by the stress light emitting material 3.

  8A and 8B illustrate the third method. According to the third method, a layer (hereinafter referred to as a paper pulp fiber layer) 15 containing a paper pulp fiber 2 containing a stress luminescent material 3 and a coat layer 16 thereon are formed according to the formation location, shape and size of the watermark region. The recess 18 is formed by removing a predetermined amount in the depth direction.

  8A is a plan view of the case where the coat layers 16 and 17 are laminated on both sides of the paper pulp fiber layer 15 and the recess 18 is formed on one coat layer 16 side, and FIG. 8B is a sectional view taken along line AA of FIG. is there.

  In the portion of the paper pulp fiber layer 15 where the recess 18 is formed, the thickness of the paper pulp fiber 2 is small, so the density of the paper pulp fiber 2 is small and the light emission intensity of the stress light emitting material 3 is high. . Although not only the paper pulp fiber 2 but also the stress light emitting material 3 is partially removed at the location where the recess 18 is formed, the transmittance is improved by the effect that the amount of the paper pulp fiber 2 is reduced. The luminous intensity of the stress-stimulated luminescent material 3 can be increased.

  As a specific method of physically scraping the vicinity of the surface of the two layers of paper pulp fibers to form the recess 18, for example, a laser for cutting can be used. If a mechanism for two-dimensionally scanning the irradiation direction of the laser light is provided, the laser light can be irradiated to any place on the surface of the two layers of paper pulp fibers, and the shape of the recess 18 formed in the paper pulp fibers 2 is arbitrary. It can be adjusted. Therefore, it is also possible to make the shape of the recess 18 a shape representing characters, symbols or images.

  9A to 9D illustrate the fourth method. The fourth method is to make the watermark region thinner than the other regions and to provide the stress light-emitting material 3 only in the watermark region. For example, in a cylinder paper machine equipped with two tank cylinders, tape of 1 cm × 1 cm size is pasted at intervals of 1 cm on the same circumferential surface of the first cylinder, and the mesh is closed. In the state, the first paper layer 20 is formed using this circular net cylinder. Thereby, as shown to FIG. 9A, the opening part 21 is formed in the place which stuck the tape.

  Next, as shown in FIG. 9B, the thread 22 including the stress luminescent material 3 is formed in the peripheral portion of the first paper layer 20 with the opening 21 using the unwinding device of the thread 22.

  Next, as shown in FIGS. 9C and 9D, the second web layer 23 is formed on the first paper layer 20 on which the thread 22 is formed, using the second web circular cylinder as it is. FIG. 9C is a plan view of the side on which the second paper layer 23 is formed, and FIG. 9D is a plan view of the opposite side. As shown in FIG. 9D, the thread 22 is exposed from the portion where the opening 21 is formed, and is thinner because the first paper layer 20 is not present, and can be used as a watermark area. Since the first paper layer 20 is not present in the watermark region, the transmittance is high, and the light emitting material 3 has improved luminous performance and high light emission intensity.

  In the example of FIG. 9A, the tapes are attached to the circular mesh cylinder at regular intervals in a row, and finally, the watermark regions are formed in a row, but it is optional by appropriately adjusting the size of the tape and the pasting location. Form a watermark area of the shape and size of Thus, it is also possible to form arbitrary characters, symbols or images in the watermark area.

  Thus, according to the first to fourth methods shown in FIG. 6A, FIG. 6B, FIG. 7A, FIG. 7B, FIG. 8A, FIG. 8B, and FIG. Therefore, for example, for the purpose of forgery prevention, it is possible to form a watermark area having arbitrary code information and the shape of an image. Thus, embodiments of the present invention are applicable to anti-counterfeit media.

Fifth Embodiment
The fifth embodiment is an example applied to a packaging container such as a medicine package. It is desirable that a packaging container for storing objects that may be counterfeit such as medicines be provided with a mechanism that can easily determine whether the product is a genuine product or an imitation product when it is opened. In the future, it may be legalized to provide such a mechanism in packaging containers for medicine and the like.

  FIG. 10 is a view showing an example of a packaging container 30 which can be used, for example, in a package for containing medicine. The packaging container 30 at least partially uses the light-emitting paper 1 described in the first to fourth embodiments described above. In the packaging container 30 of FIG. 10, when the upper lid 31 has a double structure, when the upper lid 31 is first opened, the perforation 32 of the upper lid 31 is broken with human fingers, and then the inner side of the upper lid 31 is The tongue 33 is lifted upward to be opened.

  The perforation 32 portion of the packaging container 30 is the above-described light emitting paper 1. When the perforation 32 is broken, the stress light emitting material 3 emits light by the deformation stress at that time. Therefore, if it is lighted when breaking the perforation 32, it can be recognized that it is the regular medicine put in the regular packaging container 30. For example, even if a third party who manufactured an imitation of a medicine tries to sell the imitation medicine in an imitation packaging container and sell it, unless the perforation portion is the light-emitting paper 1, when the perforation 32 is broken It does not shine. Therefore, according to the present embodiment, it is possible to determine whether the drug is an imitation, depending on whether or not the perforation 32 is illuminated, without analyzing the drug.

  As described above, according to the fifth embodiment, by incorporating the stress light emitting material 3 in the perforation 32 of the packaging container 30, it is easily determined whether or not an item stored in the packaging container 30 is a genuine product. become able to.

  In addition, instead of providing the stress light emitting material 3 at the perforation 32 of the packaging container 30, a seal is attached to the packaging container 30, the stress light emitting material 3 is provided at this seal, and light is emitted when the seal is peeled off. It is also good.

  Examples 1 to 5 described below correspond to the first embodiment.

Example 1
Softwood (a mixture of Nidonmatsu and Todomatsu) chips were disintegrated by a refiner to obtain a first suspension of unbleached mechanical pulp with a freeness of 600 ml. The first suspension is adjusted to pH 4.0 with acetate buffer, and the pulp concentration is adjusted to 3%, and then it is beaten with a single disc refiner (beating machine) until the freeness reaches 300 ml. , And a second suspension containing paper pulp fibers 2. The paper pulp fibers 2 at this time had an average thickness of 30 μm and an average length of 3.0 mm.

Separately from this, 1% of Eu serving as a luminescent center and 1% of boric acid are added to Sr ₃ Al ₂ O _{6 as} a matrix material, and placed in a predetermined forming die, and in a hydrogen-added argon reducing atmosphere, The material is fired at 1300 ° C. for 4 hours, and once made into a very thin plate having a thickness of 100 μm, it is finely pulverized and a stress-stimulated luminescent material 3 having an average diameter of about 50 μm and an average length of 3.0 mm I got

  Then, 60 parts of the stress light-emitting material 3 was mixed with 100 parts of the paper pulp fibers 2 of the above-mentioned second suspension to make a third suspension.

Furthermore, 1 part of an appropriate sizing agent 6 is added to this third suspension, and a wet paper is produced with a square hand sheet machine so as to have a basis weight of 60 g / m ^2. The light emission of Example 1 having a basis weight of 60 g / m ² after drying in a drier at 120 ° C. for 2 minutes, humidity control at 20 ° C. and 50% conditions for 24 hours, and then cutting into a 50 mm × 100 mm size Paper 1 was obtained.

  As the external load on the light emitting paper 1, when pressed with a finger of the hand, the light emitting paper 1 is deformed and emits green light, which can be visually recognized, and the authenticity of the light emitting paper 1 can be confirmed .

(Example 2)
The second suspension containing the paper pulp fibers 2 of Example 1 is manually made into a first wet paper, and on this, the stress luminescence of Example 1 is made into a suspension and used as a second wet paper This procedure was repeated three times to obtain a multi-layered wet paper, and a light-emitting paper 1 of Example 2 of the present invention was obtained in the same manner as in Example 1.

  When the light-emitting paper 1 of this Example 2 was evaluated in the same manner as in Example 1, light emission was strongly observed from Example 1.

  This is considered to be the effect that the paper pulp fiber 2 and the stress light emitting material 3 are contained in a state of being crossed each other, and in fact, the cross section of the light emitting paper 1 of the second embodiment is the same as that of the first embodiment. When compared by microscopic observation, many crossed states were observed.

(Example 3)
In Example 2, the shape of the stress-stimulated luminescent material 3 is a strip-shaped stress-stimulated luminescent material 3 having an average thickness of 20 μm, an average width of 30 μm (thickness / width ratio = 1/3), and an average length of 1.0 mm. A light-emitting paper 1 of Example 3 of the present invention was obtained in the same manner as in Example 2 except for the problem.

  When the light-emitting paper 1 of Example 3 was evaluated in the same manner as in Example 2, good results similar to those of Example 2 were obtained.

(Example 4)
Example 3 of the present invention is the same as Example 3 except that in the substantially central portion of the needle-like stress-stimulated luminescent material 3 a cut having a width of 1/2 is made on both sides of the band. A luminescent sheet 1 of Example 4 was obtained. When the light-emitting paper 1 of this Example 4 was evaluated in the same manner as in Example 3, good results similar to those of Example 3 were obtained except that light emission was observed more strongly. At this time, it was clear that the cut portion of the band of the stress light emitting material 3 had a stress concentration coefficient α of 2 or more.

(Example 5)
As sizing agent 6, it is a particle size of 1 to 10 μm, and the color difference with the color tone of the stress light-emitting material 3 of Example 1 is 0.4, and the color difference is 0.4. In the same manner as Example 1, a light-emitting paper 1 of Example 5 of the present invention was obtained.

  When the appearance of this light-emitting paper 1 was observed, it could only be recognized as a mere white paper, and it could not have been imagined that the stress light-emitting material 3 was mixed in this paper, Example 1 The same good results were obtained.

(Comparative example 1)
In Example 1, a sheet was produced without including the stress light emitting material 3 and was referred to as Comparative Example 1. When Comparative Example 1 was evaluated in the same manner as Example 1, no light emission occurred, and it was judged that the sheet was not authentic.

  Examples 6 to 10 described below correspond to the second embodiment.

(Example 6)
Softwood (a mixture of spruce and pine tree) chips were disintegrated by a refiner to obtain a first suspension of unbleached mechanical pulp with a freeness of 600 ml. The first suspension is adjusted to pH 4.0 with acetate buffer, and the pulp concentration is adjusted to 3%, and then it is beaten with a single disc refiner (beating machine) until the freeness reaches 300 ml. An appropriate mixed type sizing agent 6 was added at an appropriate ratio to form a second suspension containing the paper pulp fibers 2. The paper pulp fibers 2 at this time had an average thickness of 30 μm and an average length of 3.0 mm.

Separately from this, 1% of Eu serving as a luminescent center and 1% of boric acid are added to Sr ₃ Al ₂ O _{6 as} a matrix material, and placed in a predetermined forming die, and in a hydrogen-added argon reducing atmosphere, A light emitting material which is fired at 1300 ° C. for 4 hours and once finely divided into a thin plate having a thickness of 100 μm and finely crushed to have an average diameter of about 50 μm in cross section and an average length of 3.0 mm I got three.

  Here, the reason that the forming die is a predetermined forming die is that, even if 100% of the material is filled according to the inner shape (die shape) of the forming die, the material shrinks by the above-mentioned firing, and the forming thereof Since the shape is considerably smaller than the inner shape of the mold (shape of the mold), it means that the inner shape (shape of the mold) of the mold has been determined in anticipation of this shrinkage.

Furthermore, using the second suspension described above, a wet paper web is produced so as to have a basis weight of 60 g / m ² with a square hand-made sheet machine, and the above stress is applied to the wet paper The light emitting material 3 is positioned as the sizing agent 6 of the lamination type, and the ratio of 5 parts of the stress light emitting material 3 to 100 parts of the paper pulp fiber 2 is sprinkled directly and uniformly on the surface of the wet paper. Stacked.

Next, the drum dryer is subjected to 120 ° C. × 2 minutes of drying treatment and roll press treatment, and conditioned at 20 ° C. and 50% conditions for 24 hours, and then cut into a size of 100 mm × 200 mm, The light-emitting paper 1 of Example 6 of the present invention was obtained in an amount of 60 g / m ² .

  When a predetermined external load is applied to the light-emitting paper 1 of the sixth embodiment, the light-emitting paper 1 is deformed to emit green light and can be visually recognized. I was able to confirm the authenticity.

(Example 7)
In addition to the stress-stimulated luminescent material 3 of Example 6, aluminum oxide having the same shape as the stress-stimulated luminescent material 3 was subjected to stress-stimulated luminescence in a ratio of 2 parts of aluminum oxide to 100 parts of the paper pulp fiber 2 The light-emitting paper of Example 7 of the present invention was prepared in the same manner as in Example 6, except that the mixture of the stress light-emitting material 3 and aluminum oxide was sprinkled on wet paper in the same manner as in Example 6. I got one.

  At this time, the bulk modulus of the stress light emitting material 3 and the bulk modulus of aluminum oxide were almost the same, and both were 300 GPa.

  When the light-emitting paper 1 of this Example 7 was evaluated in the same manner as in Example 6, good results similar to those of Example 6 were obtained except that light emission was observed more strongly.

(Example 8)
In Example 6, the shape of the stress-stimulated luminescent material 3 is a strip-shaped stress-stimulated luminescent material 3 having an average thickness of 20 μm, an average width of 30 μm (thickness / width ratio = 1/3), and an average length of 1.0 mm. A light-emitting paper 1 of Example 8 of the present invention was obtained in the same manner as in Example 6 except for the difference.

  The light-emitting paper 1 of Example 8 was evaluated in the same manner as in Example 6. As a result, substantially the same good results as in Example 6 were obtained.

(Example 9)
Example 8 of the present invention is the same as Example 8 except that in the substantially central portion of the needle-like stress-stimulated luminescent material 3 a cut having a width of 1/2 is made on both sides of the band. A light-emitting paper 1 of Example 9 was obtained.

  When the light-emitting paper 1 of this Example 9 was evaluated in the same manner as in Example 8, good results similar to those of Example 8 were obtained except that light emission was observed more strongly. At this time, it was clear that the central portion (the cut portion) of the band which is the stress light emitting material 3 was a portion where the stress concentration coefficient α was 2 or more.

(Example 10)
In Example 7, the mixed type sizing agent 6 is not used, and instead of the aluminum oxide of Example 7, the laminated type sizing agent 6 has a particle size of 1 to 10 μm, and Example 6 The light-emitting paper 1 of Example 10 of the present invention was prepared in the same manner as in Example 7, except that kaolin (white clay) having a color difference of 0.4 with the color tone of the stress-stimulated luminescent material 3 was used. I got

  When the appearance of this light-emitting paper 1 was observed, it could only be recognized as a mere white paper, and Example 6 could not be imagined that the stress light-emitting material 3 was mixed in this paper. The same good results were obtained.

(Comparative example 2)
In Example 6, a sheet was produced without including the stress light emitting material 3 and was referred to as Comparative Example 2. When this comparative example 2 was evaluated in the same manner as in Example 6, no light emission occurred, and it was judged that this paper was not authentic.

  Examples 11 to 14 described below correspond to the third embodiment.

(Example 11)
Softwood (a mixture of spruce and pine tree) chips were disintegrated by a refiner to obtain a first suspension of unbleached mechanical pulp with a freeness of 600 ml. The first suspension is adjusted to pH 4.0 with acetate buffer, and the pulp concentration is adjusted to 3%, and then it is beaten with a single disc refiner (beating machine) until the freeness reaches 300 ml. , And a second suspension containing paper pulp fibers 2. The paper pulp fibers 2 at this time had an average thickness of 30 μm and an average length of 3.0 mm.

  Next, in the coating step of step S5 in FIG. 5, the second suspension is uniformly supplied in the width direction of the wire on a PET fiber woven wire (wire) at an appropriate speed and angle. Water on the net, dry at 60 ° C with hot air, and make the paper pulp fiber 2 into a net shape and a sheet shape with a water content of 25% once on the wire. Pulp and paper fibers 2 were obtained.

Separately from this, 1% of Eu serving as a luminescent center and 1% of boric acid are added to Sr ₃ Al ₂ O _{6 as} a matrix material, and placed in a predetermined forming die, and in a hydrogen-added argon reducing atmosphere, After firing at 1300 ° C. for 4 hours, a material having an extremely thin thickness of 100 μm, which is a material of the stress light emitting material 3, is finely pulverized using an impact crusher and classified by a classifier. Thus, fine particles of the stress luminescent material 3 having an average particle diameter D ₅₀ = 1.5 μm are obtained.

  Here, the reason that the forming die is a predetermined forming die is that, even if 100% of the material is filled according to the inner shape (die shape) of the forming die, the material shrinks by the above-mentioned firing, and the forming thereof Since the shape is considerably smaller than the inner shape of the mold (shape of the mold), it means that the inner shape (shape of the mold) of the mold has been determined in anticipation of this shrinkage.

  Next, fine particles of the stress light emitting material 3 were dispersed in liquefied propane gas at 1/10 by weight ratio, and a spray liquid containing fine particles of the stress light emitting material 3 was obtained.

  Then, using a motorized spray gun, the fine particles of the stress luminescent material 3 are placed on the wire on the reticulated paper pulp fiber 2 containing moisture, and a spray solution containing the fine particles of the stress luminescent material 3 is obtained. After fine particles of stress light emitting material 3 are attached to the surface of reticulated paper pulp fiber 2 by spraying, air drying at 40 degrees for 1 hour, hot air drying at 80 degrees is applied, and fine particles of stress light emitting material 3 are obtained. It was fixed to the surface of the reticulated paper pulp fiber 2. This operation was performed from the surface and the back of the reticulated paper pulp fiber 2. At this stage, the adhered fine particles of the stress-stimulated luminescent material 3 become the stress-stimulated luminescent material 3 covering the paper pulp fibers 2.

  At this time, the weight ratio of the paper pulp fibers 2 to the fine particles of the stress light emitting material 3 adhered to the surface is 100/15, and in this state, the paper pulp fibers 2 have a part of the surface emit light. It was reticulated ML coated paper pulp fibers 8 coated with material 3.

The reticulated ML-coated paper pulp fiber 8 is taken out of the wire, returned to the water tank, and demeshed to form a third suspension of the ML-coated paper pulp fiber 8 and then the third suspension thereof. Further, 1 part of an appropriate sizing agent 6 is added to 8100 parts of the ML-coated paper pulp fiber, and a wet paper is prepared with a square hand-made sheet machine so as to have a basis weight of 60 g / m ² , After drying at 120 ° C. for 2 minutes in a drum dryer and conditioning for 24 hours at 20 ° C. and 50% conditions, this is cut to a size of 100 mm × 200 mm and has a basis weight of 60 g / m ^2. A light-emitting paper 1 of Example 11 of the invention was obtained.

  As a predetermined external force load on the light-emitting paper 1 of the eleventh embodiment, when the light-emitting paper 1 is pressed with a finger of the hand, the light-emitting paper 1 is deformed to emit green light and can be visually recognized. I was able to confirm the authenticity.

(Example 12)
The twelfth embodiment differs from the eleventh embodiment in the following points. A stress light emitting material 3 dispersed resin in which fine particles of the stress light emitting material 3 having an average particle diameter D ₅₀ = 1.5 μm are dispersed in an acrylic resin (transmittance 95%) having transparency at a weight ratio of 50/100 A dipping solution was prepared, which was dissolved in a mixture of isobutyl acetate / isobutanol = 1/1. In addition, the pulping step to the second paper making step excluding the covering step of step S9 in the paper making step of FIG. 5: reticulated paper pulp fibers 2 after proceeding to the drying and pressing treatment (steps S1 to S8) The above-mentioned dipping solution is passed at a speed of 1 m / min, subjected to hot-air drying at 80 ° C. for 30 minutes, and the surface of the reticulated paper pulp fiber 2 is a stress-luminescent material 3 dispersion resin with a thickness of 2 μm. The film was coated, and almost the entire surface of the paper pulp fiber 2 was coated with the resin-dispersed stress-stimulated luminescent material 3 to form ML coated paper pulp fiber 8. Except for this point, it is the same as the eleventh embodiment.

Thereafter, a processing and finishing process was performed to obtain Luminous Paper 1 of Example 12 of the present invention having a basis weight of 60 g / m ^{2 and} having a size of 100 mm × 200 mm.

  When the light-emitting paper 1 of this Example 12 was evaluated in the same manner as in Example 11, light emission with higher intensity was obtained, and it was considered that it was considered to be superior by visibility and authenticity judgment. Good results similar to Example 11 were obtained.

(Example 13)
In Example 12, in the coating step of step s9 in FIG. 5, a star (*) shape of 100 μm in length × 100 μm in width is formed by stainless screen printing using a dispersed resin ink composition of stress light emitting material 3 described later. A print design layer aligned longitudinally and horizontally with a 200 μm cycle is applied on reticulated paper pulp fibers 2 to form a coating layer of a 3 μm thick resin dispersion type stress luminescent material 3 after drying, ML coating Paper pulp fiber 8 was used.

  This means that a printing layer is formed on the mesh (mesh) portion and a printing layer is formed on the mesh (mesh) gap because design printing is applied on the mesh (mesh) -like substrate. Since it does not (meaning that it does not remain), the remaining printing layer becomes a partial design in which the design is divided.

  In the thirteenth embodiment, the design, that is, the star shape is formed separately. In the first place, stress concentrates on the five acute angle parts of the star shape and the five obtuse angle parts in between, but the stress also concentrates on the cross section due to the division described above.

  Accordingly, the shape of the stress-stimulated luminescent material 3 having a height of 3 μm, that is, a so-called deformed pentagonal pillar having divided stars covering the top of the pulp and paper fibers 2 is a stress concentration point Is a shape in which the stress concentration coefficient α is 2 or more, and further 10 or more.

The dispersed resin ink composition of the stress luminescent material 3 contains the following materials. 10 parts of fine particles (average particle diameter D ₅₀ = 2.5 μm) of the stress-stimulated luminescent material 3 20 parts of acrylic resin (transmittance 95%). 20 parts of toluene. Ethyl acetate is 30 parts. 20 parts of ethanol.

  A light-emitting paper 1 of Example 13 of the present invention was obtained in the same manner as Example 12 except for the above.

  The light-emitting paper 1 of this Example 13 was evaluated in the same manner as in Example 12. As a result, light emission with higher intensity was obtained, and except that the visibility and the authenticity judgment were considered to be further excellent. The same good results as in Example 12 were obtained.

(Example 14)
As sizing agent 6, it is a particle size of 1 to 10 μm, and the color difference with the color tone of the stress light-emitting material 3 of Example 1 is 0.4, and the color difference is 0.4. In the same manner as in Example 11, a light-emitting paper 1 of Example 14 of the present invention was obtained.

  When the appearance of the light-emitting paper 1 is observed, it can be recognized as a mere white paper, and the stress-light-emitting material 3 and further, the ML-coated paper pulp fiber 8 are mixed in the paper Good results similar to those of Example 1 were obtained except that one could not imagine.

(Comparative example 3)
In Example 1, a sheet was produced without including the stress light emitting material 3 and was referred to as Comparative Example 3. When Comparative Example 3 was evaluated in the same manner as Example 1, no light emission occurred, and it was judged that this paper was not authentic.

  The aspects of the present invention are not limited to the above-described individual embodiments, but include various modifications that those skilled in the art can conceive, and the effects of the present invention are not limited to the contents described above. That is, various additions, modifications and partial deletions can be made without departing from the conceptual idea and spirit of the present invention derived from the contents defined in the claims and the equivalents thereof.

  1 light-emitting paper, 2 paper pulp fibers, 3 stress light-emitting materials, 5 ML fibers, 6 sizing agents, 7 ML fine particles, 8 ML coated paper pulp fibers, 11 irregularities, 14 watermark inks, 15 paper pulp fiber layers, 16, 17 coats Layers, 18 recesses, 20 first paper layer, 21 openings, 22 threads, 23 second paper layer

Claims (15)

Containing pulp and paper pulp and stress luminescent material,
The paper pulp fibers and the stress-stimulated luminescent material are arranged to be in contact at least in part,
The stress light emitting material emits light of a predetermined wavelength with a light emission intensity corresponding to the deformation stress when a deformation stress causing deformation of the paper pulp fiber is generated by an external load, and a stress concentration factor with respect to the external load light-emitting paper α to have a 2 or more sites. The light-emitting paper has at least two regions where the density of the paper pulp fibers is different,
Among the two regions, a region having a lower density of the paper pulp fibers emits light with higher emission intensity to the same deformation stress as compared with a region having a higher density of the paper pulp fibers. The light-emitting paper described in 1.   The light-emitting paper according to claim 2, wherein the outline shape of the area where the density of paper pulp fibers is lower is a shape that represents arbitrary information. In a part of the surface of the light emitting paper, an area to which visible light transmitting ink for suppressing irregular reflection of the surface is attached is provided.
The light-emitting paper according to claim 1, wherein the area emits light with higher emission intensity to the same deformation stress as compared to the other surfaces. The light-emitting sheet is provided with at least two regions having different sheet thicknesses,
The light-emitting paper according to claim 1, wherein a region having a thinner paper thickness out of the two regions emits light with higher luminous intensity to the same deformation stress as compared with a region having a larger paper thickness.   The light-emitting paper according to claim 5, wherein the outline shape of the area with a thinner paper thickness is a shape that represents arbitrary information.   The light emitting paper according to claim 1, wherein the light emitting paper includes a first region not containing the stress light emitting material but containing the paper pulp fiber, and a second region containing the stress light emitting material and the paper pulp fiber. .   The light emitting sheet according to claim 7, wherein the sheet thickness of the first area is larger than the sheet thickness of the second area.   The light-emitting paper according to claim 7 or 8, wherein the outer shape of the second area is a shape that represents arbitrary information. Containing sizing agents,
The light emitting paper according to any one of claims 1 to 9, wherein a color difference between the color tone of the sizing agent and the color tone of the stress light emitting material is 0.5 or less.   The stress-stimulated luminescent material has a needle-like or strip-like shape, has a length of 1/10 to 1/2 of the paper pulp fibers, and is disposed to intersect the paper pulp fibers. 11. A light-emitting sheet according to any one of items 1 to 10.   The light emitting paper according to any one of claims 1 to 10, wherein the stress light emitting material is laminated on the paper pulp fiber.   The light emitting sheet according to any one of claims 1 to 10, wherein the stress light emitting material coats the paper pulp fiber. An anti-counterfeit medium comprising paper pulp fibers and a stress luminescent material, wherein
The anti-counterfeit medium comprises at least two areas,
The stress light emitting material emits light with higher emission intensity to the same deformation stress in one of the two regions than the other in one of the two regions when a deformation stress causing deformation of the paper pulp fiber is generated by an external load. , the medium for preventing forgery stress concentration factor α is have a 2 or more sites to the external load. A packaging container comprising paper pulp fibers and a stress luminescent material,
Equipped with perforations or sealing members for opening;
The stress-stimulated luminescent material in the perforations or the seal member is deformed when the perforations are broken or a deformation stress that deforms the paper pulp fibers is generated due to an external load when peeling the seal member. packaging container emits light at light emission intensity corresponding to the stress, the stress concentration factor α is have a 2 or more sites to the external load.