JP2011218740A - Light-emitting printed matter - Google Patents

Abstract

The present invention relates to a luminescent printed matter in which a luminescent image that is visually recognized during irradiation with excitation light and a luminescent image that is visually recognized after the irradiation of excitation light are changed to completely different images.
The present invention relates to a luminescent printed matter having a printed image on at least a part of a substrate, wherein the printed image includes a background element group formed by arranging a plurality of background elements at a certain area ratio, and a background. An information element group in which a plurality of information elements are arranged at positions that do not overlap with the element, and the background element group includes a first print element group in which a plurality of first elements are arranged, and a second element Is divided into a second printing element group, and the printed image is visually recognized during excitation light irradiation, and only the first printing element group is visually recognized in the first time from the end of excitation light irradiation. It is the light emission printed matter characterized by being made.
[Selection] Figure 1

Description

The present invention relates to anti-counterfeiting technology using a light-emitting material used in the field of security printed matter such as banknotes, passports, securities, identification cards, cards, and passports that require anti-counterfeiting effects. The image that can be observed during the irradiation of the image and the image that can be observed after the irradiation of the excitation light are related to the luminescent printed matter that changes to a different image having no correlation.

With recent developments in digital devices such as scanners, printers, and color copiers, it has become possible to easily produce elaborate copies of precious printed matter. As one of anti-counterfeiting techniques for preventing such duplication and counterfeiting, there is a technique for forming a luminescent image using a special luminescent ink in which a fluorescent material, a phosphorescent material, a phosphorescent material, or the like is contained in the ink.

As a technique for forming a luminescent image, a technique using a so-called ultraviolet-excited visible light-emitting material in which a part of an image is visible when irradiated with ultraviolet rays is generally used. This technology uses a black light to illuminate the printed material and visually confirms that a specific part of the printed image emits light, and uses it as a standard for authenticity determination. Since simple forgery used cannot reproduce light emission, it has been widely used as one of anti-counterfeiting techniques in the field of anti-counterfeit printing.

Among these technologies for forming luminescent images, there is a technology that uses phosphorescent ink containing a phosphorescent material. Phosphorescent ink emits light in a specific color when irradiated with excitation light like fluorescent ink containing fluorescent material, but unlike fluorescent ink, it continues to emit light for a while after stopping irradiation of excitation light. The so-called afterglow has a feature. This effect can be easily observed if there is an inexpensive black light that can irradiate a single wavelength of excitation light, and it is impossible to produce this effect without using a phosphorescent material. Excellent authenticity and anti-counterfeiting effect. There are several anti-counterfeiting techniques that utilize such characteristics of phosphorescent materials to form a luminescent image having a unique effect.

For example, in Patent Document 1, there is a description of a printed matter in which an ink layer is formed by an ink material in which a phosphor having little afterglow and a phosphorescent material that has long afterglow are mixed. In this printed matter, when the emission color of the phosphor and the phosphor are different, the emission image emits a mixed color that includes the emission color of the phosphor and the phosphor when irradiated with excitation light, and the phosphor emits light for a few seconds after the excitation light irradiation. Changes to color only. Therefore, the printed matter formed by this technique has a feature that the emission color changes during and after excitation light irradiation, and has high security.

In addition, the applicant previously mixed a plurality of light emitting materials having different light emission colors with the time until the light emission intensity reaches a saturated state, so that the time elapsed from the start of excitation light irradiation can be reduced. In response to this, a printed matter in which the emission color of the ink changes is proposed (see, for example, Patent Document 2). This technology also uses the effect unique to the phosphorescent material as in Patent Document 1, and it is difficult to reproduce the characteristic that the emission color changes in a simple emission image formed using a general fluorescent ink. Therefore, it is considered to have high security.

JP 2005-67043 A JP 2007-277281 A

  However, what characterizes the techniques of Patent Document 1 and Patent Document 2 are the unique light emission characteristics of the ink. Conversely, when forming a printed image, there is no special contrivance in the configuration of the image. Each light-emitting image is simply a binary image formed by the presence or absence of halftone dots, or a gradation image formed by changing the halftone dot area ratio or the density of halftone dots. In other words, a light-emitting image that appears when an excitation light is irradiated to a certain area in a printed image causes a unique color change due to the light-emitting ink, but the image itself changes from one image to a different image. There was a problem that there was no change effect.

Moreover, the special light emission color change of the technique of patent document 1 and patent document 2 is dependent on the light emission characteristic of light emitting materials, such as a fluorescent material and a phosphorescent material. At present, it is easy for ordinary people who are not involved in special printing through general stores or the Internet to obtain light emitting materials such as various fluorescent materials and phosphorescent materials. It is possible to mimic the effect of changing color as well as the genuine product. Therefore, in order to maintain a high anti-counterfeit effect using this technique, a light emitting material that cannot be easily imitated even if a commercially available material is used is indispensable. From the above, in order to maintain a high anti-counterfeit effect in this technique, a light-emitting material with a high degree of availability is essential.

The present invention is intended to solve the above-described problems, and is a luminescent printed matter in which an image is formed by a complex pixel and / or image line structure formed by a set of special luminescent ink and halftone dots. The luminescent image visually recognized by the observer while irradiating the excitation light on the image and the luminescent image visually recognized by the observer after the irradiation of the excitation light are changed into different images having no correlation. In addition, the present invention relates to a light-emitting printed matter excellent in authenticity determination and anti-counterfeiting effects.

The present invention provides a light-emitting printed material having a printed image on at least a part of a substrate, wherein the printed image is a background element group formed with a certain area ratio formed by arranging a plurality of background elements, and the background element. An information element group in which a plurality of information elements are arranged at positions that do not overlap, and the background element group includes a first print element group in which a plurality of first elements are arranged, and a second element Are divided into a second print element group, and the first element and the second element have the same shape, and the second print element group and the information element group are: The first printing element group is formed of a second ink, and the first ink and the second ink have the same wavelength of excitation light, and , The color emitted by the excitation light is visually recognized as the same color, and the first ink The afterglow is not visible after the excitation light irradiation is finished, and the second ink is visible after the excitation light irradiation is finished, and the printing is performed during the excitation light irradiation. In the light-emitting printed matter, only the first printing element group is visually recognized while an image is visually recognized and a first time elapses from the end of the excitation light irradiation.

The present invention is the light-emitting printed matter, wherein the second ink has a hue different from the emission color during excitation light irradiation and the emission color of afterglow.

The present invention is the light-emitting printed material, wherein the first time is 5 ms or longer and 30 seconds or shorter.

The present invention is a light-emitting printed matter in which the background element is an image line or a pixel.

The present invention is the luminescent printed matter, wherein the information element is an image line or a pixel.

The present invention is the light-emitting printed matter in which the first ink and the second ink are transparent ink, ink of the same color as the base material, or light-colored ink.

The present invention is the luminescent printed matter, wherein the first ink and / or the second ink contains at least one of an infrared absorbing pigment, a glittering material, a photochromic pigment, and a thermochromic material.

  In the luminescent printed matter of the present invention, the luminescent image visually recognized by the observer while the print area is irradiated with the excitation light and the luminescent image visually recognized by the observer after stopping the excitation light irradiation are completely correlated. Since the image is changed to a different image having no image, it has an excellent image change effect.

The luminescent printed material of the present invention can be produced by using two paired inks having different luminescent properties, such as those commercially available as a luminescent material. However, unless a complicated pixel and / or image line configuration is used, it is impossible to develop the image change effect of the present invention. Therefore, the anti-counterfeit effect in the present invention is caused not by a special light emitting material but by its complicated pixel and / or image line configuration. From the above, in order to maintain a high anti-counterfeit effect in this technique, a light-emitting material with a high degree of availability is not essential.

The top view which shows the luminescent printed material (1) of this invention. The top view which shows the background element group (4) and information element group (5) which form a print image (3). The top view which shows the positional relationship of the background element (6) which forms a background element group (4), and the information element (7) which forms an information element group (5). The top view which shows the 1st printing element group (8) which comprises a background element group (4), and the 2nd printing element group (9). The top view which shows the 2nd printing element group (9) and information element group which are formed with the 1st ink, and the 1st printing element group (8) which is formed with the 2nd ink. The figure which shows the emission spectrum in the excitation light irradiation of the 1st ink and the 2nd ink, and the emission spectrum after completion | finish of ultraviolet irradiation. The observation figure at the time of the ultraviolet irradiation of the luminescent printed matter (1) of this invention, and after completion | finish of ultraviolet irradiation. The top view which shows the light emission printed matter (1-1) in this invention. The top view which shows the background element group (4-1) and information element group (5-1) which form a printing image (3-1). The top view which shows the positional relationship of the background element (6-1) which forms a background element group (4-1), and the information element (7-1) which forms an information element group (5-1). The top view which shows the 1st printing element group (8-1) which comprises a background element group (4-1), and a 2nd printing element group (9-1). The top view which shows the 2nd printing element group (9-1) and information element group which are formed with the 1st ink, and the 1st printing element group (8-1) which is formed with the 2nd ink. The observation figure at the time of ultraviolet irradiation of the luminescent printed matter (1-1) of this invention, and after ultraviolet irradiation. The top view which shows the light emission printed matter (1-2) in this invention. The top view which shows the background element group (4-2) and information element group (5-2) which form a printing image (3-2). The top view which shows the positional relationship of the background element (6-2) which forms a background element group (4-2), and an information element group (5-2). The top view which shows the 1st printing element group (8-2) and the 2nd printing element group (9-2) which comprise a background element group (4-2). The top view which shows the 2nd printing element group (9-2) and information element group which are formed with the 1st ink, and the 1st printing element group (8-2) which is formed with the 2nd ink. The observation figure at the time of the ultraviolet irradiation of the luminescent printed material (1-2) of this invention, and after the ultraviolet irradiation completion.

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

FIG. 1A shows a luminescent printed material (1) according to the present invention. In the luminescent printed material (1), the printed image (3) is formed on the base material (2). The printed image (3) includes the background element group (4) shown in FIG. It is composed of an information element group (5) shown in (c). In the drawing, characters of “printing station” formed in the printed image (3) with an area ratio different from that of the background element group (4) can be recognized by the gradation difference, but irradiated with ultraviolet rays. If not, the “printing station” of the print image (3) cannot actually be recognized.

FIG. 2 shows a background element group (4) and an information element group (5) that form the print image (3). The background element group (4) shown in FIG. 2 (a) is formed by regularly arranging a plurality of background elements (6) having a fixed shape, as shown in the enlarged view. As shown in the enlarged view, the information element group (5) shown in FIG. 2 (b) regularly arranges a plurality of information elements (7) having a certain shape so that the character “printing station” can be displayed. Forming.

FIG. 3 shows the positional relationship between the background element (6) forming the background element group (4) and the information element (7) forming the information element group (5). As shown in FIG. 3, a plurality of information elements (7) are regularly arranged at positions that do not overlap with the background element (6), and the character “printing station” of the Chinese character is formed in the printed image (3). In other words, the print image (3) has information in a position that does not overlap the background element (6) in the flat gradation created by the background element group (4) formed by arranging a plurality of background elements (6). A configuration in which a plurality of elements (7) are regularly arranged to form the information element group (5), thereby allowing the observer to visually recognize characters of “printing station” having a gradation different from that of the background element group (4); It has become.

The background element (6) and the information element (7) in the present invention are formed by pixels or image lines. The “pixel” referred to here is a block of image elements formed by collecting a plurality of halftone dots, which are the minimum units for forming the print image (3). The shape may be a circle, polygon, star, or the like. Well, other special characters and symbols are also included. An “image line” is an image element formed by continuously arranging halftone dots in a certain direction without a gap, and is a broken line, broken line, straight line, curved line, or wavy line. Even a linear configuration is included in the technical idea of the present invention.

In the present invention, the background element (6) forming the background element group (4) is composed of pixels and / or image lines. One information element group (5) may be formed by arranging a plurality of information elements (7) that are pixels or image lines, and conversely, it does not form pixels or image lines that are information elements (7). It may be composed of binary images such as characters and symbols formed depending on the presence or absence of dots, or may be composed of a gradation image such as a photograph formed by the size of halftone dots or density (described later in Example 2). . What is important in the formation of the information element group (5) is to form the information element group (5) with a plurality of information elements (7) as long as the information element group (5) is satisfied. There is no problem even if the binary image or the gradation image is used as the information element group (5) as it is. The meaning of forming in a position that does not overlap is to create a gradation difference by forming a region having a different area ratio from the background element group (4) in the printed image (3), and to make the observer visually recognize significant information. That is.

The combination of the background element (6) forming the background element group (4) and the information element (7) forming the information element group (5) is the present invention in all combinations of pixels and / or image lines. Can be produced. In the embodiment for carrying out the present invention, the element (6) forming the background element group (4) and the element (7) forming the information element group (5) are circular pixels. I will explain it.

In this embodiment, the background element group (4) is formed from a plurality of background elements (6) made up of pixels of a certain size, and the information element group (5) forms the background element group (4). However, it is not necessary to be limited to this form, and the present invention is not limited to a flat type of the information element (7). The area ratio may be varied depending on the information element group (5) so as to produce a gradation difference with respect to the background element group (4) having gradation.

  The background element (6) and the information element (7) need to be formed so as not to overlap. This is because if the background element (6) and the information element (7) are formed overlappingly, the light emission of the overlapping part becomes a composite light emission color of the first ink and the second ink, which is stronger than the surroundings. This is because an unclear light emission image with uneven light emission is obtained. The detailed description of the first ink and the second ink will be described later.

  FIG. 4 shows two elements constituting the background element group (4). FIG. 4B shows the first printing element group (8), and FIG. 4C shows the second printing element group (9). In the drawing, although “NPB” of the first printing element group (8) can be recognized, the characters “NPB” of the first printing element group (8) are changed before or during the irradiation with ultraviolet rays. I can't recognize it. In the first printing element group (8) shown in FIG. 4 (b), a plurality of first elements (10) having a fixed shape are regularly arranged to constitute the letters “NPB” of the alphabet. . The second printing element group (9) shown in FIG. 4C is configured by regularly arranging a plurality of second elements (11) having the same area ratio as the first element (10). In this configuration, the characters “NPB” of the first print element group (8) are removed from the background element group (4).

Therefore, the background element (6) is either the first element (10) or the second element (11), and the background element group (4) is the first printing element group and the second element (4). A group of printing elements is composed. As described above, the first print element group (8) and the second print element group (9) form a pair image, and characters, symbols, and the like included in the first print element group (8). The meaningful image is camouflaged by the second printing element group (9) as a pair, and is hidden in the background element group (4) having a certain gradation.

  In order to obtain an effect in which the first printing element group (8) is camouflaged by the second printing element group (9) and hidden in the background element group (4) having a certain gradation, The first element (10) and the second element (11) need to have the same area ratio, and even when the first element (10) and the second element (11) are enlarged and displayed with a magnifying glass or the like. Therefore, it is most desirable that the first element (10) and the second element (11) have the same shape.

  FIG. 5A shows a second printing element group and an information element group formed with the first ink in the present invention, and FIG. 5B shows a first printing element formed with the second ink in the present invention. Show groups. FIG. 5A shows an image formed with the first ink, and has a configuration in which the information element group (6) and the second printing element group (9) are combined. FIG. 5B is an image formed with the second ink, and is composed of only the first printing element group (8). As described above, the second printing element group (8) formed with the first ink and the first printing element group (9) formed with the second ink are combined to form the background element group (4). And the information element group (5) formed with the first ink is added to the background element group (4), thereby forming the printed image (3) formed on the light-emitting printed matter of the present invention. .

Next, the first ink and the second ink used in the present invention will be described. FIG. 6A shows the emission spectra of the first ink and the second ink during irradiation with excitation light, and FIG. 6B shows the emission after the excitation light irradiation of the first ink and second ink. The spectrum is shown. The first ink and the second ink are excited by light of the same wavelength. In addition, the first ink and the second ink that are being irradiated with the excitation light are visually recognized as the same color, and the second ink is used while the excitation light irradiation ends and the first time elapses. Only the light emission due to the afterglow is visible, and the light emission of the first ink is not visible.

An example of specific optical characteristics required for the pair ink used for the first ink and the second ink will be described. The emission spectrum during excitation light irradiation of the print sample formed with the first ink and the print sample formed with the second ink on the substrate (2) is shown in the graph of FIG. The later emission spectrum is shown in FIG. The sample for measuring the emission spectrum is obtained by using a general white fine paper as the base material (2) and printing the first ink and the second ink at 100%. Further, a spectrofluorophotometer F-4500 (manufactured by Hitachi High-Technologies Corporation) was used for the measurement of the emission spectrum.

  Hereinafter, for the sake of clarity, the “printed sample formed with the first ink on the substrate (2)” will be referred to as the “first sample” and the “printed sample on the substrate (2)”. The “printed sample formed with the second ink” is referred to as “second sample”.

  FIG. 6A shows the emission spectrum (12) of the first sample during excitation light irradiation and the emission spectrum (13) of the second sample during excitation light irradiation. From the graph of FIG. 6A, it can be seen that the emission spectra of the first sample and the second sample are substantially the same and are observed as equal colors. In FIG.6 (b), the emission spectrum (14) of the 2nd sample after completion | finish of excitation light irradiation is shown. In addition, since the 1st sample is not light-emitted after excitation light irradiation completion | finish, an emission spectrum does not exist in a graph. From this graph, it can be seen that the first sample does not emit light after the excitation light irradiation ends, but the second sample emits light.

  From the above results, if the area ratio of the image formed on the substrate (2) with the first ink and the image formed on the substrate (2) with the second ink is equal, It is observed that the same color is observed during the excitation light irradiation, but only the image formed with the second ink is visible during the first time after the excitation light irradiation.

  Based on the above results, the effect of the luminescent printed material (1) of the present invention will be described. Fig.7 (a) shows the image visually recognized by an observer in the middle of irradiating excitation light with respect to the luminescent printed material in this invention. FIG.7 (b) shows the image visually recognized after irradiating excitation light with respect to the luminescent printed material in this invention. As shown in FIG. 7A, when the luminescent printed material (1) of the present invention is observed during irradiation with excitation light, the second printing element group (9) formed with the first ink, Since the first printing element group (8) formed of the two inks has the same shape of the first element (10) and the second element (11) constituting each, the same color The character “NPB” indicated by the first print element group (8) is completely camouflaged by the second print element group. The observer has the area ratio of the background element group (4) having a flat gradation formed by combining the first printing element group (8) and the second printing element group (9). The information element group (5) composed of the characters “printing office” formed by the difference is observed with a stronger light emission than the background element group (4). Therefore, the printed image (3) shown in FIG.

Further, as shown in FIG. 7B, when the light emitting printed material (1) of the present invention is stopped from being irradiated with excitation light and observed during the first time, it is formed with the first ink. Since the second printing element group (9) and the information element group (5) do not emit light, only the first printing element group (8) formed of the second ink emits light. , Only the first print element group (8) consisting of the characters “NPB” is lit and viewed.

  As described above, while irradiating the luminescent printed matter (1) of the present invention with excitation light, the printed image (3) is observed, and during the first time elapses from the end of excitation light irradiation, The first print element group (8) is visible. In this way, since different images having no correlation are visually recognized during excitation light irradiation and after excitation light irradiation, the authenticity discrimination is excellent.

  In the embodiment for carrying out the present invention, skin-colored high-quality paper was used as the base material (2), but the color of the base material is not limited to the skin color. You may use the base material of the color. Moreover, there is no problem even if it is coated paper or plastic as well as high-quality paper.

  Further, the first ink and the second ink may be transparent or colored. If it is transparent, the printed image (3) appears only when the excitation light is irradiated, but if it is colored, the printed image (3) is visible even if the excitation light is not irradiated. . However, when coloring, it is desirable to keep it in light colors, such as yellow and yellowish green. When colored with a dark color such as black or brown, information colored on the background of the first print element group (8) that appears during the first time after the end of excitation light irradiation This is because the element (5) and the second printing element group (9) are visually recognized in an overlapping manner, and in some cases, the change effect is unclear. In addition, when colored with a dark color, there is a concern that the emission color of the ink may be absorbed and the emission luminance itself may decrease, so it is desirable to keep the color light when colored.

The first ink and the second ink need to be excited by light of the same wavelength, and the emission spectrum during excitation light irradiation is substantially the same, and the light emission characteristics that the observer can visually recognize with the same color It is necessary to have. In addition, the second ink needs to have an afterglow to the extent that the first ink can be visually observed after the first light irradiation. As an example of selecting such a pair ink, it is easiest to use a pair of the same color fluorescent ink and phosphorescent ink. Further, it is not necessary to prepare an ink using a single luminescent pigment, and there is no problem even if the luminescent color is adjusted by mixing a plurality of luminescent pigments in one ink. In addition, as in the second ink described in Example 2, the emission color during excitation light irradiation is the first color, and the afterglow emission color changes to a second color different from the first color. When using special inks, it is not only possible to add rich expression due to excellent image change effect, but it is also more difficult to imitate such special emission color changes It also leads to improvement of counterfeit resistance.

The first time varies depending on the purpose of use of the printed material, such as confidentiality considering anti-counterfeiting and design properties considering landmarks such as information signs, but it is necessary to determine whether the printed material is the object of the present invention. If intended, the desired time is between 5 ms and 30 s. This is because if the time is shorter than 5 ms, the observer may not be able to detect the change in the light emission image, and if it is 30 s or longer, it takes time to determine the authenticity, which is not preferable. Note that 5 ms to 30 s is the range for the first time intended for authenticity determination, and the effect of the light-emitting printed matter of the present invention itself may continue for 1000 min or more depending on the performance of the phosphorescent material used.

The excitation light of the first ink and the second ink may be any wavelength of ultraviolet light, visible light, and infrared light. Further, there is no problem even if the emission wavelength is any wavelength region of ultraviolet light, visible light, and infrared light. Even if the light emission wavelength is invisible to humans, such as ultraviolet rays and infrared rays, the light emission wavelength is converted into a visible wavelength by performing image processing using a camera equipped with an element that can receive light of each wavelength. Since it is easy to do, even if the emission wavelength is an invisible wavelength, the observer can observe the image change effect of the present invention on the premise of mechanical processing. However, from the viewpoint of facilitating authenticity determination, it is desirable that the emission wavelength is visible light that allows an observer to directly observe the image change.

A special authentication function may be imparted by mixing a functional material other than the light emitting material with the first ink and / or the second ink. For example, it is possible to add an infrared authentication function even under reflected light by mixing an infrared absorbing pigment in any of the inks. In addition, bright materials, photochromic pigments, thermochromic materials, etc. can be added to the ink. By mixing, a printed matter with higher designability and functionality can be formed.

  The printing method of the luminescent printed material in the present invention can be formed by any printing method such as offset printing, flexographic printing, letterpress printing, gravure printing, screen printing, intaglio printing, IJP and the like. In addition, when forming by IJP, what is called variable printing which changes the information of an output thing for every sheet can be implemented.

  Moreover, about the structure of the element for forming the light emission printed matter (1) of this invention, it is not restrict | limited to the structure as described in embodiment. As a configuration of the elements, the first printing element group (8) and the second printing element group (9) are combined to form a fixed background element group (4), and the background element group (4) It is only necessary that the print image is configured by forming the information element group (5) at a position that does not overlap with the image.

  Hereinafter, although the Example of the luminescent printed material produced specifically according to the best form for implementing the above-mentioned invention is described in detail, this invention is not limited to this Example.

A first embodiment of the present invention will be described with reference to FIGS. In Example 1, white quality paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as the base material (2-1).

FIG. 8A shows a luminescent printed material (1-1) in the present invention. In the luminescent printed matter (1-1), the printed image (3-1) is formed on the substrate (2-1), and the printed image (3-1) is a background element shown in FIG. It is composed of a group (4-1) and an information element group (5-1) shown in FIG. In the background element group (4-1) shown in FIG. 9A, a plurality of background elements (6-1) which are image lines having an image line width of 0.25 mm are regularly arranged at a pitch of 0.5 mm. Formed. The information element group (5-1) illustrated in FIG. 9C includes an information element (7-1) that is an image line having the same line width of 0.25 mm as the background element (6-1), and the background element group (5-1). 4-1) Regularly arranged at a pitch of 0.5 mm so as not to overlap with each other, thereby forming a “printing station” character in Chinese characters. FIG. 10 shows the positional relationship between the background element (6-1) forming the background element group (4-1) and the information element (7) forming the information element group (5-1). The printed image (3-1) includes a background element (6-1) and a flat gradation generated by a background element group (4-1) formed by arranging a plurality of background elements (6-1). By arranging a plurality of information elements (7-1) regularly at positions where they do not overlap to form an information element group (5-1), "printing" with a gradation different from that of the background element group (4-1) It is the structure which makes an observer visually recognize the character of "station".

  FIG. 11 shows two elements constituting the background element group (4-1). FIG. 11B shows the first printing element group (8-1), and FIG. 11C shows the second printing element group (9-1). The first printing element group (8-1) shown in (b) is a configuration showing the letters “NPB” of the alphabet. In the second printing element group (9-1) shown in FIG. 11C, the characters “NPB” of the first printing element group (8-1) are extracted from the background element group (4-1). It becomes the composition.

  FIG. 12 shows respective images formed by the first ink and the second ink. FIG. 12A shows an image formed with the first ink, and has a configuration in which the information element group (5-1) and the second printing element group (9-1) are combined. The image shown to Fig.12 (a) was printed on the base material (2-1) by screen printing using the 1st ink produced with the mixing | blending shown in Table 1. FIG. FIG. 12B is an image formed with the second ink, and is composed of only the first printing element group (8-1). The image shown in FIG. 12B was printed on the substrate (2-1) by printing using the second ink having the composition shown in Table 2.

  When the first ink and the second ink are printed on the substrate with the same area ratio, when the excitation light of 365 nm is irradiated, the first ink and the second ink are observed in green having an emission peak in the vicinity of 520 nm which is visually equal, and the second ink The ink has visible afterglow even after 60 minutes from the irradiation of excitation light, and the first ink has no afterglow. Both the emission and afterglow of the first ink are green emission colors having an emission peak in the vicinity of 520 nm. The green phosphorescent pigment mixed with the second ink was N long-lasting phosphor (manufactured by Nemoto Special Chemical), a long persistence phosphorescent material.

  The effect in Example 1 of this invention is demonstrated using FIG. When 365 nm ultraviolet rays were irradiated to the luminescent printed material (1-1) of the present invention, the printed image (3-1) appeared in a green luminescent color as shown in FIG. 13 (a). Further, as shown in FIG. 13B, when the ultraviolet irradiation was stopped and the observation was made 1 second after the ultraviolet irradiation was completed, the first printing element group (8-1) was also found to have a green afterglow. It was confirmed that it appeared. Thus, it was confirmed that different images having no correlation appeared during observation during excitation light irradiation and after irradiation with excitation light.

A second embodiment of the present invention will be described with reference to FIGS. In Example 2, skin-colored high-quality paper (manufactured by Nippon Paper Industries Co., Ltd.) was used as the base material (2-2).

FIG. 14A shows a luminescent printed material (1-2) in the present invention. As shown to Fig.14 (a), as for the luminescent printed matter (1-2), the printed image (3-2) is formed on the base material (2-2), and the printed image (3-2) is FIG. 14B includes a background element group (4-2) and an information element group (5-2) illustrated in FIG. 14C. The background element group (4-2) shown in FIG. 15A was formed by regularly arranging a plurality of background elements (6-2), which are pixels having a diameter of 0.25 mm, at a pitch of 0.5 mm. The information element group (5-2) shown in FIG. 15 (b) is not an aggregate of a plurality of elements, but only a region that is formed by a single element and overlaps the background element (6-2) is outlined. By doing so, the characters “printing station” were formed so as not to overlap with the background element (6-2). In this example, since the information element group (5-2) directly forms a binary image depending on the presence or absence of a halftone dot, unlike the embodiment and Example 1, there is no information element.

FIG. 16 shows a background element (6-2) that forms a background element group (4-2) and an information element group (5-2). The information element (5-2) shown in FIG. 16 forms the characters “printing station” so as not to overlap with the background element (6-2). The print image (3-2) includes the background element (6-2) and the flat gradation generated by the background element group (4-2) formed by arranging a plurality of background elements (6-2). By forming the information element group (5-2) at a position that does not overlap, the viewer is able to visually recognize the characters of the “printing station” having a different gradation from the background element group (4-2). .

FIG. 17 shows two elements constituting the background element group (4-2). FIG. 17B shows the first printing element group (8-2), and FIG. 17C shows the second printing element group (9-2). The first printing element group (8-2) shown in FIG. 17B is a configuration showing the letters “NPB” of the alphabet, and the second printing element group (9-2) shown in FIG. ) Has a configuration in which the characters “NPB” of the first print element group (8-2) are removed from the background element group (4-2).

  FIG. 18 shows respective images formed by the first ink and the second ink. FIG. 18A shows an image formed with the first ink, which is configured by combining the information element group (5-2) and the second printing element group (9-2). The image shown in FIG. 18A was printed on the substrate (2-2) by screen printing using the first ink prepared with the formulation shown in Table 3. FIG. 18B shows an image formed with the second ink, which is composed of only the first printing element group (8-2). The image shown in FIG. 18B was printed on the substrate (2-2) by printing using the second ink having the composition shown in Table 4.

When the first ink and the second ink are printed on the substrate with the same area ratio, when the excitation light of 365 nm is irradiated, the same color is visually observed, and the second ink is irradiated with the excitation light. Even after 0.1 seconds, it has a visible afterglow, and the first ink has no afterglow. The emission of the first ink and the second ink when irradiated with excitation light is a slightly greenish white emission color, the first ink has no afterglow, and the second ink has a red afterglow. Have.

  The effect in Example 2 of this invention is demonstrated using FIG. When the 365-nm ultraviolet light was irradiated to the luminescent printed material (1-2) of the present invention, as shown in FIG. 19B, the ultraviolet light irradiation was stopped and the ultraviolet light irradiation was terminated for 0.1 seconds. Later, the first printing element group (8-2) appeared with a red afterglow color. Thus, it was confirmed that different images having no correlation appeared during observation during excitation light irradiation and after irradiation with excitation light.

1, 1-1, 1-2 Luminous printed matter 2, 2-1, 2-2 Base material 3, 3-1, 3-2 Print image 4, 4-1, 4-2 Background element group 5, 5-1 5-2 Information element group 6, 6-1 and 6-2 Background element 7, 7-1 Information element 8, 8-1 and 8-2 First print element group 9, 9-1 and 9-2 Second printing element group 10, 10-1, 10-2 First element 11, 11-1, 11-2 Second element 12 Emission spectrum 13 during irradiation of excitation light of first ink 13 of second ink Emission spectrum 14 during excitation light irradiation Emission spectrum after second light excitation light irradiation

Claims (7)

In a luminescent printed material provided with a printed image on at least a part on a substrate,
The print image includes a background element group formed by arranging a plurality of background elements at a constant area ratio, and an information element group at a position that does not overlap with the background element. Divided into a first printing element group comprising a plurality of one element and a second printing element group comprising a plurality of second elements,
The first element and the second element have the same shape,
The second printing element group and the information element group are formed of a first ink,
The first printing element group is formed of a second ink,
The first ink and the second ink have the same excitation light wavelength, and the emission color of the excitation light is visually recognized as the same color,
The first ink is invisible afterglow after the excitation light irradiation,
Afterglow of the second ink is visible after the irradiation of the excitation light,
During the irradiation of the excitation light, the printed image is visually recognized,
Only the first print element group is visually recognized while the first time elapses from the end of the excitation light irradiation. The luminescent printed matter according to claim 1, wherein the second ink has a hue in which the emission color during irradiation of the excitation light is different from the emission color of the afterglow. The luminescent printed matter according to claim 1 or 2, wherein the first time is 5 ms or more and 30 s or less. The luminescent printed matter according to any one of claims 1 to 3, wherein the background element is an image line or a pixel. The luminescent printed matter according to any one of claims 1 to 4, wherein the information element group is formed by arranging a plurality of information elements which are image lines or pixels. The luminescent printed matter according to any one of claims 1 to 5, wherein the first ink and the second ink are transparent ink, ink of the same color as the base material, or light-colored ink. . The luminescent printed matter according to claim 1, wherein the first ink and / or the second ink contains at least one of an infrared absorbing pigment, a glittering material, a photochromic pigment, and a thermochromic material. .

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