JP6075230B2 - Luminescent printed matter - Google Patents

Description

  The present invention is an image that can be observed under visible light in the field of valuable printed materials such as banknotes, passports, securities, identification cards, cards, and passports, which are security printed materials that require anti-counterfeiting effects. However, it relates to a luminescent printed matter that changes to a completely different image when irradiated with ultraviolet rays.

  A so-called ultraviolet-excited illuminant typified by a phosphor, a phosphor, a phosphorescent substance, and the like has a characteristic of being excited to emit light when irradiated with ultraviolet rays. This phenomenon of light emission can be easily visually confirmed, and it is difficult to reproduce it with a copy produced by a copying machine or an output produced by a home printer, so it is a genuine product for security printed matter such as banknotes and securities. Conventionally, it has been widely used as one of the authenticity determination elements for distinguishing between counterfeits and counterfeit products.

  The superiority of illuminant printing as authenticity authentication technology used to depend on the difficulty of obtaining the material itself, where only a limited number of specialists or special printing personnel can obtain the illuminant. . However, recently, light emitters are sold at a relatively low price in general merchandise stores, etc., and even ordinary people who are not engaged in special printing can easily obtain various types of light emitters. Therefore, the value of a technique for forming a simple light-emitting image, which has only the effect of causing a light-emitting image to appear by irradiating ultraviolet rays, has been greatly reduced.

  In view of these circumstances, a more unique visual effect is realized by using a complex image structure and special functional materials instead of the conventional simple light-emitting image in which a light-emitting image simply appears when irradiated with ultraviolet rays. A light-emitting image and a method for forming the same are disclosed. An example of those techniques is shown.

  The present applicant has already formed a curve pattern, a portion where the latent image is not applied is a continuous line, and a portion where the latent image is applied is formed by a branched dividing line. The printed matter has an anti-copying pattern characterized by being printed with, and when viewed under visible light, it is recognized as a simple curved aggregate pattern. Has been filed for a printed matter that emits intense light (see, for example, Patent Document 1).

  In addition, the present applicant has already provided an image display body that causes a different image to appear by using a functional image display material whose visible color changes depending on conditions, and is adjacent to one first region and the first region. A plurality of sets of one second region are arranged, and the periphery of each second region is surrounded by the plurality of first regions, and the first region constituting the first image is included in the first region. And a first background area other than the first dot area, and the second area includes a second dot area constituting the second image, and a second dot area other than the second dot area. The first background area and the second background area using the functional image display material, and the first dot area provided with the functional image display material. It is characterized by the use of an image display material of the same color as the color, and an image that can be seen with the naked eye and a specific visual recognition under normal light Filed an image display that has a different image change effect than the images that can be seen under the conditions (including when irradiated with ultraviolet light), that is, the images observed when irradiated with normal light and ultraviolet light are completely uncorrelated. (For example, refer to Patent Document 2).

  In addition, the present applicant has already used a luminescent material having excitation characteristics with significantly different emission intensities in different wavelength ranges of the ultraviolet region, and has a luminescence image that appears when the first ultraviolet ray in a certain wavelength region is irradiated. And a luminescent image that appears when the second ultraviolet ray in a wavelength region different from that of the first ultraviolet ray is irradiated, each printed with a different configuration with a difference in predetermined dot area ratio, image line pitch, and the like, An image forming body has been filed in which an ultraviolet absorber is printed thereon to change the light emission image between ultraviolet rays having a first wavelength and ultraviolet rays having a second wavelength (see, for example, Patent Document 3).

Japanese Patent No. 4085175 JP 2008-126474 A Japanese Patent No. 4635170

  Although the technique described in Patent Document 1 is formed with only one type of colored fluorescent ink, it is visually recognized as a collection of curves by constructing only a latent image with extremely fine pixels. Among the images, the latent image has an excellent feature that it emits light stronger than the surroundings. However, since the latent image is composed of fine pixels that are close to the limit of the size that can be reproduced by printing, it is difficult to control the dot gain, and the luminescent image does not produce the desired effect depending on the degree of dot gain generation. There was a problem that manufacturing difficulty was high. In addition, although the latent image appears in the set of curves due to the irradiation of ultraviolet rays, there is no effect of making the set of curves invisible, and the image itself changes from one image to a different image. There was a problem that there was no change effect and change was scarce.

  The technique described in Patent Document 2 is a technique having a so-called image change effect in which, when an image A is visible under visible light, A disappears and an image B appears when irradiated with ultraviolet rays. Therefore, compared with the conventional technique, it has the characteristics that it is excellent in the change of the image and the visibility of the luminescent image can be kept high. However, in order to keep the image change effect high, three types of ink (one functional display material and two colored inks) are required, and in addition, three images composed of three types of inks Since the most difficult printing called so-called “tweeping”, which is completely adjacent to each other without overlapping areas, requires extremely high technology for stable and continuous production. In addition, in order to cause the image of A to disappear and the image of B to appear at the time of ultraviolet irradiation, it was necessary to change the colors of the two regions that were non-isochromatic under visible light to the same color at the time of light emission. . In order to produce a pair of inks that have the same reflected color but have the same color at the time of light emission, specialized knowledge about the illuminant and the ink is necessary, and even if it can be produced, observing the printed matter that emits light, Due to the difference in emission color or emission intensity, the color was usually different enough to be perceived by the observer. As described above, the technique described in Patent Document 2 has a problem that the difficulty of ink production and printed matter production is extremely high.

  In the technique described in Patent Document 3, if an image A is visible under visible light, for example, when ultraviolet longwave is irradiated, A disappears and an image B appears, for example, when ultraviolet shortwave is irradiated. Is a technology that has a more advanced image change effect, in which an image called C appears. Compared with the conventional technology, three images can be visually recognized according to the wavelength of light used for observation. Have. However, similarly to the technique described in Patent Document 2, the technique described in Patent Document 3 must strictly match the positional relationship between the two images, and requires high printing accuracy. Moreover, it is necessary to adjust the luminescence intensity of the luminescent ink in accordance with each wavelength, and it is difficult to produce the ink. In addition, the visible image and the light-emitting image are limited to relatively simple binary images, and there is a problem that design restrictions are large.

  The present invention aims to solve the above-described problems, and an image observed under visible light, an image that appears by irradiating ultraviolet long waves, and an image that appears by irradiating ultraviolet short waves are completely present. A light-emitting printed material with excellent image change effect, characterized by different uncorrelated images, low manufacturing difficulty, stable continuous manufacturing, and very few design restrictions The present invention relates to a luminescent printed material.

  The present invention provides a first image formed by halftone dots on at least a part of a substrate having a characteristic that the reflectance of ultraviolet long waves when irradiated with ultraviolet rays is greater than the reflectance of ultraviolet short waves. The second image and the third image are provided with a printed image laminated in order from the base material, and the first image is formed of a first colorant having the same color as a transparent or base material having ultraviolet longwave absorption ability, The second image is a second color material having a color different from that of the base material having ultraviolet light emission ability throughout the region, and the difference between the maximum halftone dot area ratio and the minimum halftone dot area ratio is 10% or more and 60% or less. The third image has an ultraviolet shortwave absorption ability and does not have ultraviolet emission ability and ultraviolet longwave absorption ability, or emits light in a color different from that of the second image. Transparent and does not have ultraviolet long-wave emission ability and ultraviolet long-wave absorption ability. 3. It is formed of the coloring material 3, and only the second image, the first image, or the third image can be visually recognized by observation under visible light, observation by ultraviolet long wave irradiation, or observation by ultraviolet short wave irradiation, respectively. Is a luminescent printed matter characterized by

  In the luminescent printed matter of the present invention, when the substrate is white, the second colorant is characterized in that the color of the colored pigment and the luminescent color of the luminescent pigment have a complementary relationship.

  In the luminescent printed matter of the present invention, the three images of the printed image that are visible under visible light, the image that appears when irradiated with ultraviolet long waves, and the image that appears when irradiated with ultraviolet short waves are completely correlated. This is a different image having no image, and has an image change effect according to the wavelength of light to be irradiated. This image change effect does not appear as one image overlaps another image as in the prior art, and three images are completely isolated and displayed according to the wavelength of the irradiated ultraviolet rays. . In addition, since all three appearing images have high visibility, the authenticity discrimination is excellent.

  In the luminescent printed matter of the present invention, the image appearing when irradiated with ultraviolet longwaves and the image appearing when irradiated with ultraviolet shortwaves do not need to be provided with gradation restrictions, and of course binary images such as characters and marks. In addition, it is possible to easily express a multi-tone image such as a person or a landscape having a very wide gradation expression range. In addition, although it is necessary to provide gradation limitation for an image that is visible under visible light in a printed image, the gradation expression range is wider and the limitation on design is smaller than that of the conventional technique. As described above, the degree of freedom in design is high compared to the conventional technology.

  In the luminescent printed material of the present invention, the three types of inks that form a printed image do not need to be the same color under visible light or when irradiated with ultraviolet light, and therefore, color matching between the inks is not necessary and the production is easy. In addition, the three images formed with the respective inks do not require high-precision printing as in the prior art, and the three images may simply overlap each other. In addition, since the changing effect can be achieved without strictly managing the dot gain, the manufacturing difficulty is low and stable continuous manufacturing is possible.

  The luminescent printed matter formed by the above method can be manufactured by offset printing, which is a highly productive printing method, so it has excellent cost performance, and even if the latest digital equipment is used, the luminescent image cannot be reproduced. Therefore, it is excellent in anti-counterfeiting effect.

The luminescent printed material in this invention is shown. The outline | summary of a structure of the light emission printed matter in this invention is shown. The laminated structure of three images of a luminescent printed matter is shown. The image at the time of observing the luminescent printed material in this invention on different observation conditions is shown. The luminescent printed matter in one Example of this invention is shown. The outline | summary of a structure of the light emission printed matter in one Example of this invention is shown. The image at the time of observing the luminescent printed matter of Example 1 in this invention on different observation conditions is shown.

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.
(First embodiment)

  FIG. 1 shows a luminescent printed material (1) in the present invention. The luminescent printed matter (1) is formed by forming a printed image (3) having a color different from that of the substrate (2) on the substrate (2). The substrate (2) may be transparent or opaque and may be colored without any problem. Further, the base material (2) needs to have a characteristic that the reflectance of the ultraviolet long wave is larger than the reflectance of the ultraviolet short wave. However, the quality paper, coated paper, plastic, etc. used for general printing have this characteristic. Therefore, no special consideration is required for the material of the base material (2) unless a special metal or the like is used as the base material (2).

  The “characteristic in which the reflectance of the ultraviolet long wave is greater than the reflectance of the ultraviolet short wave” to be included in the base material (2) in the present specification refers to the integral value of the ultraviolet reflectance in the ultraviolet long wave region (center wavelength 365 nm ± 20 nm). Is 1.3 times or more the integral value of the ultraviolet reflectance in the ultraviolet shortwave region (center wavelength 254 nm ± 20 nm). As an example, in the case of general high-quality paper or coated paper, this value is about 1.5 to 3 times.

  Further, even if the base material (2) in which the reflectance of the ultraviolet long wave is larger than the reflectance of the ultraviolet short wave is not used, the material having the characteristic that the reflectance of the ultraviolet long wave is larger than the reflectance of the ultraviolet short wave (the ultraviolet short wave rather than the ultraviolet long wave). The base material (2) may be imparted with the above-mentioned properties by printing or coating the base material (2) in advance with a material having a property of strongly absorbing the light and forming a base. Since there are a large number of resins having the characteristics as described above, the resin may be selected according to the compatibility with the substrate (2).

  The printed image (3) may be a color different from the base material other than transparent, and the size is not limited as long as it fits in the base material (2). In addition, in the printed image (3) of the luminescent printed matter (1) in FIG. 1, there are images in which three letters “A”, “B”, and “C” of the alphabet can be seen. When the actual print image (3) is observed under visible light, only the letters “A” of the alphabet can be observed, and the letters “B” and “C” of the alphabet Cannot be observed.

  First, the configuration of the print image (3) of the present invention is shown in FIG. The printed image (3) includes a second image (5) that is a visible image having the first significant information (5A), a first image (4) representing the second significant information, and a third significant image. And a third image (6) representing information. In the present embodiment, a description will be given of a mode in which the images represented by the respective images described above are simple binary images. The second image (5) is composed of a plurality of halftone dots and is formed of a second color material having a color different from that of the base material, and the difference between the maximum halftone dot area ratio and the minimum halftone dot area ratio in the image. Is formed within 60%. In the present invention, the “area ratio” is a ratio of the area of halftone dots arranged in a certain area of the base material (2), and is constant in the halftone dots constituting each image. The difference between the maximum area ratio and the minimum area ratio of the halftone dots arranged in the area is within 60%.

  The first image (4) is composed of a plurality of halftone dots and needs to be formed of the first color material having the same color as the base material (2) or a transparent color. Subsequently, the third image (6) is composed of a plurality of halftone dots and needs to be formed of a third color material having a transparent color. In the embodiment, the first significant information is the letter “A” of the alphabet, the second significant information is the letter “B” of the alphabet, and the third significant information is “C” of the alphabet. Is the character.

  Further, the second color material that forms the second image (5) has a so-called ultraviolet light emission ability that emits light when irradiated with ultraviolet rays, and the first image (4) absorbs ultraviolet long waves. It is necessary to have a so-called ultraviolet long wave absorption ability. The third color material that forms the third image (6) has a so-called ultraviolet shortwave absorption ability that absorbs ultraviolet shortwaves, or emits ultraviolet shortwaves to emit light of the second image (5). It is necessary to have a so-called ultraviolet short-wave light emitting ability that emits light with a color different from that of the ultraviolet light. In the first embodiment, the third color material forming the third image (6) will be described by taking as an example a form having ultraviolet shortwave absorbing ability to absorb ultraviolet shortwave.

  There are no particular restrictions on the configuration of the halftone dots that make up the second image (5), the first image (4), and the third image (6), and shades can be expressed by their size and density. As long as there is only an AM screen or FM screen. Further, there is no problem even if the second image (5), the first image (4), and the third image (6) are configured using image lines formed by collecting halftone dots, pixels, and the like. . In addition, there is no restriction on the positional relationship between the halftone dots. The above is the outline of the configuration of the print image (3) of the present invention.

  The “halftone dot” in the present invention is a small point having a minimum unit for forming the print image (3). These are dotted lines, broken lines, broken lines, straight lines, curved lines, and broken lines arranged continuously at a certain distance in a specific direction, and at least one printing halftone dot or a plurality of printing halftone dots are collected into a lump. Pixels include various figures such as a triangle, a polygon including a quadrangle, and a star, or letters, symbols, and numbers. That is, in the present invention, an image line, a pixel, and the like are considered as one of variations of the halftone dot configuration.

  FIG. 3 shows the layer structure of the printed image (3). In the printed image (3) of the present invention, first, the first image (4) is formed immediately above the base material (2) with the first color material having ultraviolet long-wave absorption ability. ) To form a second image (5) with a second colorant having ultraviolet light emission ability, and on the second image (5), a third image having ultraviolet shortwave absorption ability or ultraviolet shortwave emission ability. The third image (6) is formed with the color material. This laminated structure needs to be superposed in this order, and the intended effect of the present invention is lost regardless of which image layer is replaced.

  Here, the performance required for the second image (5) will be specifically described. In the second image (5), the first significant information (5A) is represented by shades of an arbitrary color under visible light, while the entire image emits light evenly when irradiated with ultraviolet rays, and the first significant information ( 5A) needs to be a flat luminescent image that cannot be visually recognized. The excitation wavelength of the second image (5) needs to include at least the long wave (central wavelength 365 nm) to the short wave (central wavelength 254 nm) of ultraviolet rays. The form of light emission may be any of fluorescence, phosphorescence, and phosphorescence, and the emission wavelength may be in the visible region or invisible region such as the infrared region. However, in consideration of authenticity, those having an emission wavelength in the visible region are desirable.

  In order to eliminate a certain shading in the second image (5) visually recognized under visible light visually upon irradiation with ultraviolet light, the color under visible light of the second image (5) and when irradiated with ultraviolet light It is necessary to balance the emission intensity. For example, when the second image (5) is formed in a dark color, the light intensity of the second image (5) needs to be high, while the second image (5) has a light color. If formed, the light emission intensity of the second image (5) needs to be low. If the second image (5) is formed in a dark color but the light emission intensity is low, the first significant information (5A) is not completely lost even when irradiated with ultraviolet rays, and the density is slightly higher. When the emission intensity is high despite the fact that the second image (5) is formed in a pale color while being observed in a pale color, the first significant information (5A ) Is emitted too strongly and the negative / positive state is reversed.

  The color of the second image (5) is basically determined by the kind of color pigment contained in the image line of the second image (5) formed of the second color material and its blending ratio, and the emission intensity. Is basically determined by the type of light-emitting pigment contained in the image line forming the second image (5) and its blending ratio. If the mixing ratio of the coloring pigment and the luminescent pigment is not balanced, the disappearance effect of the first significant information (5A) at the time of ultraviolet irradiation will be lost. In each case, it is necessary to find an appropriate blending ratio. As a simple way of distinguishing the proper blending ratio, when the first significant information (5A) in the second image (5) is visually recognized at the time of ultraviolet irradiation, the blending ratio of the luminescent pigment is relative. On the contrary, when the first significant information (5A) in the second image (5) is visually recognized as a negative, it is considered that the blending ratio of the coloring pigment is relatively insufficient. Good. When the substrate (2) is white, it is preferable that the color of the color pigment and the emission color of the luminescent pigment are basically in a complementary color relationship. This is to make the color of the second image (5) at the time of ultraviolet irradiation closer to the color of the base material and enhance the image disappearance effect by making the composite color of the object color and emission color of the two pigments white. is there.

  In addition, in order to eliminate a certain shading in the second image (5) visually recognized under visible light visually upon irradiation with ultraviolet rays, the gradation expression area of the second image (5), that is, the second The difference between the minimum halftone dot area ratio and the maximum halftone dot area ratio in the image (5) is also important. Even if the image is formed by appropriately adjusting the color pigment and the luminescent pigment, if the gradation expression area is 100% (the dark area has an area ratio of 100% and the light area has an area ratio of 0%) The first significant information (5A) in the second image (5) does not disappear visually when irradiated with ultraviolet rays. In order to visually disappear the first significant information (5A) when irradiated with ultraviolet rays, it is necessary to always provide a certain gradation limit for the second image (5).

  When the gradation representation area of the second image (5) is widened, the visibility of the first significant information (5A) under visible light is increased, but the first significant information (5A) is irradiated during ultraviolet irradiation. ) Is difficult to lose, and conversely, if the gradation representation area of the second image (5) is narrowed, it is easy to lose the first significant information (5A) during UV irradiation. The visibility of the first significant information (5A) under visible light is low. Therefore, the second image (5) is displayed in a gradation expression range that can achieve both the visibility of the first significant information (5A) under visible light and the disappearance effect of the first significant information (5A) during ultraviolet irradiation. ) Must be formed.

  Specifically, when the gradation representation area of the second image (5) is lower than 10%, the visibility of the first significant information (5A) under visible light is too low, and the second image (5) If the gradation representation area of the second image (5) exceeds 60%, the effect of disappearance of the first significant information (5A) at the time of ultraviolet irradiation cannot be obtained, so the gradation representation area of the second image (5) is 10% or more. Therefore, it is necessary to reset an appropriate gradation expression range every time the color pigment or the luminescent pigment contained in the image forming the second image (5) changes.

  As described above, in forming the second image (5), the color under visible light and the emission intensity at the time of ultraviolet irradiation are adjusted in a well-balanced manner, and within the gradation expression range of 10% to 60%. It is necessary to find an appropriate value from

  Next, the performance required for the first image (4) will be specifically described. The first color material for forming the first image (4) is invisible under visible light, and needs to have an ultraviolet long wave absorbing ability to absorb ultraviolet long waves. In addition, it is essential to have an ultraviolet longwave absorbing ability that absorbs ultraviolet longwaves, but most materials having such an ultraviolet longwave absorbing ability have a characteristic of absorbing ultraviolet shortwaves in most cases. For the first image (4) of the present invention, there is no problem even if it has ultraviolet shortwave absorption capability at the same time as long as it has ultraviolet longwave absorption capability.

  Although the first image (4) is formed in the printed image (3), it must not be viewed under visible light. Therefore, the first color material for forming the first image (4) needs to be transparent or the same color as the base material (2).

  Next, the performance required for the third image (6) will be specifically described. The third color material for forming the third image (6) is invisible under visible light and needs to have an ultraviolet shortwave absorbing ability to absorb ultraviolet shortwaves. Note that the third color material for forming the third image (6) must not have an ultraviolet long wave absorbing ability to absorb ultraviolet long waves, and is excited to emit light when irradiated with ultraviolet long waves. , Must not have the ability to emit ultraviolet light.

  The third image (6) is formed on the uppermost layer in the printed image (3) and should not be viewed under visible light. Therefore, the third color material for forming the third image (6) needs to be transparent.

  The ultraviolet absorbing ability can be imparted by using a specific pigment or resin. An example of a material having ultraviolet absorbing ability is given. Typical examples of inorganic ultraviolet absorbers that can be used as pigments include zinc oxide, titanium oxide, cerium oxide, and iron oxide, and these have particularly high ultraviolet absorption characteristics. In addition, all organic compounds containing halogen, carbonyl group, benzene ring, unsaturated group and the like have a characteristic of absorbing ultraviolet rays, but salicylic acid type absorbers, benzophenone type ultraviolet absorbers, benzotriazole type Typical examples include ultraviolet absorbers and cyanoacrylate ultraviolet absorbers.

  In particular, benzotriazole-based ultraviolet absorbers are known to have remarkable absorption characteristics in the ultraviolet long wave region (wavelength 400 nm to 300 nm). The first image (4) can be formed using the above materials.

  Polyurethane resin, polyurea resin, polyamide resin, polyester resin, polycarbonate resin, aminoaldehyde resin, melamine resin, polystyrene resin, acrylic resin, styrene acrylic copolymer, gelatin, polyvinyl alcohol, etc. It is known to have a characteristic of absorbing particularly a short wavelength region of ultraviolet shortwave. The third image (6) can be formed using these materials.

  Utilizing the characteristics of these pigments and resins, an ink having an ultraviolet absorbing ability is prepared to form the first color material and the third image (6) for forming the first image (4). Therefore, printing may be performed using the third color material. However, considering printability, fastness, light resistance, etc., it is considered difficult to ensure that the resin component has long-term UV absorption capability. Most preferred is an ink in a form that ensures the above.

  The effect of the luminescent printed material (1) formed with the above configuration will be described with reference to FIG. As shown to Fig.4 (a), when the luminescent printed matter (1) of this invention is observed by observation under visible light irradiated from common visible light sources (7), such as the sun and a fluorescent lamp, a printed image ( The first image (4) formed with the first color material that is transparent or the same color as the substrate (2) and the third image (6) formed with the third color material in 3) Only the second image (5) formed with the second color material that cannot be visually recognized and has a color different from that of the base material (2) can be visually confirmed, and is specifically included in the second image (5). The first significant information (5A) can be visually recognized by the color shade formed by the difference in area ratio.

  Moreover, as shown in FIG.4 (b), when the ultraviolet-ray long wave (9L) is irradiated and the light-emitting printed matter (1) of this invention is observed, the 1st significant information (5A) in a printed image (3) The third significant information cannot be visually recognized, and only the second significant information represented by the first image (4) can be visually recognized. The principle of this effect is as follows.

  When the ultraviolet long wave (9L) is irradiated, the entire second image (5) having a light emitting ability emits light uniformly, resulting in a flat light emission image in which the first significant information (5A) cannot be visually recognized. The ultraviolet long wave (9L) directly incident on the second image (5) is not used up all at once for the excitation of the second image (5), part of which contributes to the excitation. Most of the ultraviolet long wave (9L) that did not contribute to this excitation without passing through the second image (5) without being reflected is reflected again on the surface of the substrate (2) to the second image (5). And come back. However, since the first image (4) having the ultraviolet long wave (9L) absorption ability exists below the second image (5), the first image (4) is below the second image (5). If there is, the ultraviolet long wave (9L) is absorbed, and if there is no first image (4), a part of the ultraviolet long wave (9L) is absorbed by the base material (2) and partly Is reflected back to the second image (5) after being reflected by the substrate (2). Depending on whether or not the ultraviolet long wave (9L) is re-reflected, the intensity of light emission of the second image (5) is further increased and the second significant information of the first image (4) is visualized. Moreover, since the ultraviolet-ray irradiated at this time is a ultraviolet long wave (9L), the 3rd image (6) which has only ultraviolet short-wave absorption ability passes, and the 3rd significant information remains invisible.

  Next, as shown in FIG.4 (c), when the ultraviolet-ray short wave (9S) is irradiated and the luminescent printed matter (1) of this invention is observed, 1st significant information (5A) and 2nd significant information are Only the third significant information represented by the third image (6) cannot be visually recognized. This is because the second image (5) having light emission emits light, resulting in a flat light emission image in which the first significant information (5A) is not visible, while the third image (6) is an ultraviolet short wave (9S). This is because the third significant information of the third image (6) is visualized against the back of the flat light emission image created by the second image (5). Further, unlike the ultraviolet long wave (9L), the ultraviolet short wave (9S) is energy in a wavelength region that is absorbed by general high-quality paper, coated paper, plastic, or the like, which is the base material (2). Unlike the ultraviolet long wave (9L), the ultraviolet short wave (9S) that has passed through (5) is not selectively absorbed only by the first image (4) but also by the base material (2). Therefore, little re-reflection from the substrate (2) occurs, and the first image (4) is not visualized and remains invisible.

As described above, in the observation under visible light, the first significant information (5A) represented by the second image (5) appears, and the first image (4) when observed by irradiating with ultraviolet long waves. The second significant information represented by ## EQU2 ## appears, and the third significant information represented by the third image (6) appears when observed by irradiating ultraviolet shortwave. This is the effect of the light-emitting printed matter (1) of the present invention. By changing the observation conditions, the first significant information (5A), the second significant information, and the third significant information are not mixed and completely changed. The biggest feature is that it can be observed.
(Second embodiment)

  Subsequently, a mode in which the third image (6) has an ultraviolet shortwave light emission capability, unlike the first embodiment, that is, the mode in which the third image (6) has an ultraviolet shortwave absorption capability will be described. Since the present embodiment is the same as the first embodiment except for the function of the third image (6), the drawings used for the description are the same as FIGS. 1 to 4 used in the first embodiment. We will use it. Further, matters not specifically described are the same as those in the first embodiment.

  The luminescent printed material (1) in the second embodiment is as shown in FIG. The characteristics of the substrate (2) are the same as in the first embodiment. First, the configuration of the print image (3) of the present invention is shown in FIG. The print image (3), like the print image (3) of the first embodiment, represents the second image (5) representing the first significant information (5A) and the second significant information. It consists of a first image (4) and a third image (6) representing third significant information. The second image (5) is composed of a plurality of halftone dots and is composed of a second color material having a color different from that of the base material, and the difference between the maximum halftone dot area ratio and the minimum halftone dot area ratio in the image is 60%. Formed within. The first image (4) is composed of a plurality of halftone dots and needs to be formed of the first color material having the same color as the base material or a transparent color. Subsequently, the third image (6) is composed of a plurality of halftone dots and needs to be formed of a third color material having a transparent color. The first significant information (5A) in the embodiment is the letter “A” of the alphabet, the second significant information is the letter “B” of the alphabet, and the third significant information is the letter of the alphabet The letter “C”.

  The second color material that forms the second image (5) has a so-called ultraviolet light emission ability that emits light when irradiated with ultraviolet rays, and the first color that forms the first image (4). The material needs to have a so-called ultraviolet long wave absorbing ability that absorbs ultraviolet long waves. The third color material forming the third image (6) has a so-called ultraviolet short-wave light emitting ability that emits light in a color different from the emission color of the second image (5) by irradiating the ultraviolet short wave.

  FIG. 3 shows the layer structure of the printed image (3). In the printed image (3) of the present invention, first, the first image (4) is formed on the substrate (2) side with the first color material having ultraviolet long-wave absorption ability, and the first image (4). A second image (5) is formed on the second image (5) with ultraviolet light emission ability, and a third color material (3) with ultraviolet shortwave light emission ability is formed on the second image (5). The image (6) is formed. Since the performance required for the second image (5) is the same as that of the first embodiment, the description thereof is omitted. In forming the second image (5), as in the first embodiment, the color under visible light and the emission intensity at the time of ultraviolet irradiation are adjusted in a well-balanced manner, and the floor is 10% or more and 60%. It is necessary to find an appropriate value from the key expression area. Since the performance required for the first image (4) is the same as that of the first embodiment, the description thereof is omitted.

  The performance required for the third image (6) will be specifically described. The difference in the image configuration between the second embodiment and the first embodiment is only the difference in the configuration of the third image (6). In the second embodiment, the third image (6) is invisible under visible light, and needs to have an ultraviolet shortwave light emitting ability that emits light when excited by ultraviolet shortwave irradiation. The third image (6) must not have an ultraviolet long wave absorption ability to absorb ultraviolet long waves, but should have an ultraviolet long wave emission ability that emits light when excited by irradiation with ultraviolet long waves. Don't be.

There are many light-emitting materials that have an ultraviolet short-wave light emission ability that is excited when irradiated with ultraviolet long waves and does not have ultraviolet light emission ability that emits light and emits light when irradiated with ultraviolet short waves. For example, MgWO ₃ does not emit light in the ultraviolet long wave, is excited by the ultraviolet short wave and emits blue light, and Zn ₂ SiO ₄ : Mn does not emit light in the ultraviolet long wave, emits green light by being excited by the ultraviolet short wave, and LaPO ₄ : Ce and Tb do not emit light in the ultraviolet long wave, are excited by the ultraviolet short wave and emit green light, and ZnS: Cu and Al do not emit light in the ultraviolet long wave and emit light in green when excited by the ultraviolet short wave, Y ₂ O ₃ : Eu does not emit light in the ultraviolet long wave, is excited by the ultraviolet short wave and emits red light, and (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn does not emit light in the ultraviolet long wave, is excited by the ultraviolet short wave and red. Flashes on. The light emitting material as described above is suitable as a material constituting the third image (6) of the light emitting printed matter (1).

  Further, the third color material forming the third image (6) in the second embodiment needs to emit light in a color different from the emission color of the second image (4) at the time of ultraviolet short wave irradiation. is there. For example, if the second image (4) emits green light when irradiated with short waves, the third image (6) emits light in a hue other than green, for example, red, orange, yellow, blue, etc. There is a need. When the second image (4) and the third image (6) emit light in the same color during the ultraviolet short wave irradiation, it is sufficient between the second image (4) and the third image (6). This is because no significant color difference occurs and the visibility of the third significant information is lowered. If the emission colors of the third image (6) and the second image (4) are similar hues such as green, blue, green and yellow, the third image (6) and the second image (2) It is desirable to greatly vary the emission intensity of the image (4).

  The effect of the luminescent printed material (1) formed with the above configuration will be described with reference to FIG. As shown to Fig.4 (a), when the luminescent printed matter (1) of this invention is observed by observation under visible light irradiated from common visible light sources (7), such as the sun and a fluorescent lamp, a printed image ( In 3), the first image (4) formed with the first color material that is transparent or the same color as the base material and the third image (6) formed with the third color material are not visible. Only the second image (5) having a color different from that of the substrate can be visually recognized. Specifically, the first significant information (5A) included in the second image (5) is based on the difference in area ratio. It can be visually recognized by the shade of the formed color.

  Moreover, as shown in FIG.4 (b), when the ultraviolet-ray long wave (9L) is irradiated and the light-emitting printed matter (1) of this invention is observed, the 1st significant information (5A) in a printed image (3) The third significant information cannot be visually recognized, and only the second significant information represented by the first image (4) can be visually recognized. Moreover, since the ultraviolet-ray irradiated at this time is a ultraviolet long wave (9L), the 3rd image (6) remains invisible.

  Next, as shown in FIG.4 (c), when the ultraviolet-ray short wave (9S) is irradiated and the luminescent printed matter (1) of this invention is observed, 1st significant information (5A) and 2nd significant information are Only the third significant information represented by the third image (6) cannot be visually recognized. This is because the second image (5) having light emission emits light, resulting in a flat light emission image in which the first significant information (5A) cannot be visually recognized, while the third image (6) is caused by ultraviolet shortwaves. By emitting light in a color different from that of the second image (5), the third significant information of the third image (6) is visualized against the flat light emission image created by the second image (5). Because. In addition, unlike the ultraviolet long wave (9L), the ultraviolet short wave (9S) irradiated at this time is not selectively absorbed only by the first image (4) but also by the base material (2). In addition, little re-reflection from the substrate (2) occurs and the first image (6) remains invisible.

  As described above, in the observation under visible light, the first significant information (5A) represented by the second image (5) appears, and the first image (4) when observed by irradiating with ultraviolet long waves. The second significant information represented by ## EQU2 ## appears, and the third significant information represented by the third image (6) appears when observed by irradiating ultraviolet shortwave. The light-emitting printed matter (1) of the present invention can be observed with completely changed without mixing the first significant information (5A), the second significant information, and the third significant information by changing the observation conditions. The biggest feature.

  A structural feature of the luminescent printed material (1) of the present invention is that the first color material having the ultraviolet long-wave absorption ability is formed under the second image (5) formed by the second color material having the ultraviolet light emission ability. That is, the first image (4) is formed. This layer structure is necessary not for realizing the effect at the time of ultraviolet long-wave irradiation but for realizing the effect at the time of ultraviolet short-wave irradiation. If only the effect at the time of ultraviolet long wave irradiation is to be realized, the ultraviolet long wave is present regardless of whether the first image (4) is in the upper layer of the second image (5) or the first image (4) is in the lower layer. Since the absorption function is exhibited without much difference, in any case, it is possible to realize the effect that the second significant information appears by absorbing the ultraviolet long wave. However, in general, a material having ultraviolet longwave absorption ability also has ultraviolet shortwave absorption ability. Therefore, when the first image (4) is formed on the upper layer of the second image (5), ultraviolet shortwave irradiation is performed. Even in this case, the second significant information is visualized. In this case, since the third significant information and the second significant information that are visualized by irradiating ultraviolet shortwave are mixed and viewed as an unclear image, the three images of the present invention are completely changed. The effect cannot be realized.

  However, when the first image (4) is formed in the lower layer of the second image (5) in the production of the luminescent printed material (1) of the present invention, the first image (4) is formed. Even if the color material has UV shortwave absorption ability, if the base material (2) has a characteristic of reflecting ultraviolet longwaves more strongly than ultraviolet shortwaves, the second significant information is not visualized during UV shortwave irradiation. Newly found. For this reason, the first color (4) is formed with the first color material having the ultraviolet long wave absorption ability under the second image (5) with the second color material having ultraviolet light emission ability. Thus, it is possible to realize a structure capable of realizing the effect of completely changing the three images.

  The “visible light” in the present invention refers to light having a wavelength of 400 nm to 700 nm in the luminescent printed material (1). In addition, “ultraviolet wave” refers to light included in a wavelength band from 400 nm to 300 nm with a center wavelength of 365 nm, and “ultraviolet short wave” refers to light in a wavelength band from 200 nm to 300 nm with a center wavelength of 254 nm. Refers to the light contained.

  In the present invention, “color” represents a color including the concept of hue, saturation, and brightness, and “hue” refers to a color aspect such as red, blue, and yellow. Specifically, it shows the intensity distribution of a specific wavelength in the visible light region (400 nm to 700 nm).

  The printing method of the first image (4), the second image (5), and the third image (6) having the above performance may be any printing method. The light-emitting printed material (1) of the present invention exhibits a sufficient effect even when formed by offset printing, but may be formed by flexographic printing, gravure printing, letterpress printing, intaglio printing, screen printing, or the like. When productivity is important, it is desirable to form by offset printing.

  The second image (5) needs to emit light by irradiation with ultraviolet longwave and ultraviolet shortwave, but the emission color emitted by the ultraviolet longwave may be different from the emission color emitted by the ultraviolet shortwave. In the case where the emission color of the second image (5) changes according to the wavelength of the irradiated ultraviolet light, the second significant information appearing during the ultraviolet longwave irradiation and the third appearing during the ultraviolet shortwave irradiation. Adds the effect of observing in different colors with significant information. Such a form is more desirable because not only the color expression becomes rich, but also the authenticity is improved and the resistance against forgery is also improved.

  The second image (5) may be composed of a second color material using a dichroic luminescent pigment in order to impart a characteristic that changes the emission color when irradiated with ultraviolet long waves and ultraviolet short waves. As dichroic luminescent pigments, Honeywell Japan's “LUMILUX CD-R / GI” (red light emission by ultraviolet long wave, yellow light emission by ultraviolet short wave) and “LUMILUX R / G CD770” (yellow light emission by ultraviolet long wave, ultraviolet short wave) DE-RB manufactured by Nemoto Special Chemical Co., Ltd. (blue light emission with ultraviolet long wave, red light emission with ultraviolet short wave), DE-RG (green light emission with ultraviolet long wave, red light emission with ultraviolet short wave), DE-GB (ultraviolet light) Long-wave blue light emission, ultraviolet short wave green light emission), DE-GR (ultraviolet long wave red light emission, ultraviolet short wave green light emission), etc. are on the market. If you want to achieve a unique combination of luminescent colors, mix a luminescent material that emits light in any color with long-wave ultraviolet radiation and a luminescent material that emits light in different colors with short-wave ultraviolet radiation into the same ink. What is necessary is just to produce.

  Also, a first color material for forming the first image (4), a second color material for forming the second image (5), and a third image (6) for forming the third image (6). Functional materials such as IR absorbing pigments, photochromic pigments, temperature indicating materials, and thermochromic materials may be added to the third color material. In this case, various functionalities can be added in addition to the image switching effect. .

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

  This embodiment will be described with reference to FIGS. In this embodiment, the first image (4-1), the second image (5-1), and the third image (6-1) are each a multi-tone image, and each image is offset printing. In this example, the third image (6-1) is an example having ultraviolet absorbing ability.

  FIG. 5 shows a light-emitting printed material (1-1) in the present invention. The light-emitting printed matter (1-1) is formed by forming a light purple printed image (3-1) on the substrate (2-1). As the substrate (2-1), general white fine paper (manufactured by Nippon Paper Industries Co., Ltd.) was used.

  The configuration of the print image (3-1) of the present invention is shown in FIG. The printed image (3-1) is a male face which is the first significant information (5A) on the first image (4-1) representing the image of the eyelid, which is the second significant information. The second image (5-1) representing the image is overlapped, and the third image (6-1) representing the image of the ukiyo-e that is the third significant information is superimposed thereon.

  The first image (4-1) shown in FIG. 6 is a multi-gradation image represented by gradations with a gradation expression range of 100%, with a minimum halftone dot area ratio of 0% and a maximum halftone dot area ratio of 100%. . The first image (5-1) represents a male face image that is the first significant information (5A), and has a gradation expression area 50 having a minimum halftone dot area ratio of 50% and a maximum halftone dot area ratio of 100%. It is a multi-tone image expressed in% gradation. The third image (6-1) is a multi-gradation image represented by gradations having a gradation expression range of 100%, with a minimum halftone dot area ratio of 0% and a maximum halftone dot area ratio of 100%.

  First, the base image (2-1) is a first image with a white pigment (manufactured by Best One GIGA White M-SOYA T & K TOKA) containing a metal pigment having an ultraviolet long wave absorption ability centered at 365 nm and titanium. (4-1) was formed by a wet offset printing method. The first image (4-1) is white, which is the same color as the substrate (2-1), and is directly applied to the substrate (2-1) before forming the second image (5-1). Printed. At this stage, the first image (4-1) was white and the same color as that of the base material (2-1), and thus became invisible visually.

  Subsequently, using the ink shown in Table 1, the second image (5-1) was printed on the first image (4-1) by the same wet offset printing method. The inks in Table 1 were prepared by mixing three inks. The second image (5-1) appears purple when viewed under visible light, but emits a slightly whitish green when irradiated with ultraviolet longwaves having a central wavelength of 365 nm, and yellow when irradiated with ultraviolet shortwaves. Lights up with a strong orange flavor.

Table 1

  Subsequently, the third image (6-1) is overlaid on the second image (5-1) by wet offset printing using an ink having an ultraviolet shortwave absorbing ability (made by Matte Media T & K TOKA). Printed together.

  The effect of the luminescent printed material (1-1) produced with the above structure is demonstrated using FIG. As shown in FIG. 7A, in the observation under visible light, the first significant information (5A) represented by the second image (5-1) was visually recognized by a purple shade. Next, in the case of observing by irradiating a long ultraviolet ray having a central wavelength of 365 nm, the second image (5-1) emits whiteish green and the first significant information (5A) is obtained. Disappearing, the second significant information represented by the first image (4-1) does not emit light and is visually recognized as dark sunken purple, and as a result, it darkened in whiteish green light emission Purple second significant information was visible. Finally, when observed by irradiating an ultraviolet short wave having a central wavelength of 254 nm, the second image (5-1) emits orange light, and the first significant information (5A) disappears. The third significant information represented by the image (6-1) in FIG. 6 is not emitted, and is visually recognized in a dark sunken purple color. As a result, in the orange light emission, the third significant information in the dark sunken purple can be visually recognized. It was.

  As described above, it was confirmed that the first significant information, the second significant information, and the third significant information can be completely changed and observed according to the observation conditions without being mixed.

DESCRIPTION OF SYMBOLS 1, 1-1 Luminous printed matter 2, 2-1 Base material 3, 3-1 Print image 4, 4-1 First image 5, 5-1 Second image 6, 6-1 Third image 7, 7-1 Visible light source 8, 8-1 Viewer's viewpoint 9L, 9L-1 Ultraviolet long wave light source 9S, 9S-1 Ultraviolet short wave light source

Claims (2)

Reflectance of ultraviolet longwave when irradiated with ultraviolet light, have a greater characteristic than the reflectivity of the ultraviolet short, and, in at least part of the area on the substrate having a UV short wave absorptivity, which is formed by dots The first image, the second image, and the third image comprise a printed image laminated in order from the base material,
It said first image have a UV long wave absorption capability, and is formed by the first color material of the color and transparent or the substrate under the visible light,
The second image, the entire region, have a UV emission ability, and a second color material, the minimum halftone dot area and the maximum area coverage of color different from the base material under visible light The rate difference is formed in the range of 10% or more and 60% or less,
The third image has ultraviolet shortwave absorption ability and does not have the ultraviolet emission ability and the ultraviolet longwave absorption ability, or emits ultraviolet shortwave having a color different from the emission color of the second image. Having a light emitting ability, and having no ultraviolet long wave light emitting ability and the ultraviolet long wave absorbing ability , and formed of a transparent third color material under visible light ,
Light emission characterized in that only the second image, the first image, or the third image can be visually recognized by observation under visible light, observation by ultraviolet long wave irradiation, and observation by ultraviolet short wave irradiation, respectively. Printed matter.   2. The luminescent printed material according to claim 1, wherein when the substrate is white, the second colorant has a complementary color relationship between the color of the color pigment and the luminescent color of the luminescent pigment.

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