Special light-emitting printed matter

Abstract

To provide printed matter capable of hiding the presence of phosphorescent material by disabling light emission of the phosphorescent material to be recognized.SOLUTION: There is provided special light-emitting printed matter that has, on at least a part of a base material, a special light-emitting print layer consisting of a first color layer and a second color layer laminated on the first color layer, wherein the first color layer is formed by arranging a first color region formed of first color material and a second color region formed of second color material of a different color from the first color material, and the second color layer is formed of third color material containing fluorescent material which has a first light emission color complementary to the color of the first color material with excitation light of a predetermined wavelength range and also similar to the color of the second color material, and phosphorescent material which has a second light emission color similar to the color of the first color material after ceasing of the excitation light and also complementary to the color of the second color material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention is a special luminous printed matter in which the luminescent colors of the fluorescent and phosphorescent lights are complementary to the colors of the underlying print, so that different images are recognized when excitation light is turned on and off. [Background technology]

[0002] In recent years, luminescent materials have come to be widely used as an anti-counterfeiting measure in security products such as domestic and foreign banknotes and other securities. A technology is now commonly known that uses simple discriminating tools such as ultraviolet lamps or UV-LEDs to check the luminescence and determine whether the note is genuine or not.

[0003] Furthermore, in recent years, because fluorescent materials and fluorescent inks have become relatively easy to obtain, a technology has been disclosed in which a phosphorescent material, which has a characteristic of having an afterglow even when the excitation light source is turned off, is used as an illuminant with different luminescence properties from these, and the afterglow is confirmed visually or with a discrimination device to determine authenticity.

[0004] As an example of a technology utilizing fluorescence and phosphorescence, a technology has been disclosed in which an emissive printed layer containing fluorescent and phosphorescent materials is formed into a strip, and the excitation light is moved along the longitudinal direction of the strip to confirm the color change caused by the switch between fluorescence and phosphorescence, thereby determining authenticity (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2020 / 110458 publication Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology of Patent Document 1 is a technology for confirming color changes due to switching between fluorescent and phosphorescent colors by the movement of irradiated light, and the recognized image does not change. In addition, since a similar effect can be obtained by simply mixing fluorescent and phosphorescent materials, there is a problem that it is easily imitated.

[0007] The present invention aims to solve the above problems and to provide a printed matter which changes the perceived image by making the colors of a color layer which is a mixture of fluorescent material and phosphorescent material and a colored color layer complementary to each other, thereby providing a great deal of effectiveness in preventing counterfeiting. [Means for solving the problem]

[0008] The present invention provides a special luminescent printed layer on at least a portion of a substrate, the special luminescent printed layer comprising a first color layer and a second color layer laminated on the first color layer, the first color layer being configured with a first color region formed by a first color material and a second color region formed by a second color material of a different color from the first color material, the second color layer being configured with a fluorescent material having a first luminescent color which is complementary to the first color material and similar to the second color material when exposed to excitation light in a predetermined wavelength range, and a third color material containing a phosphorescent material having a second luminescent color which is similar to the first color material and different from the first luminescent color which is complementary to the second color material after the excitation light is stopped, the special luminescent printed material being characterized in that when the special luminescent printed layer is irradiated with excitation light, the first color region absorbs the first luminescent color and is dark, and the second color region does not absorb the first luminescent color and is bright, and when the excitation light is stopped, the second color region absorbs the second luminescent color and is dark, and the first color region does not absorb the second luminescent color and is bright. It is.

[0009] The present invention is a special luminescent printed matter characterized in that, when one of the first and second luminescent colors is green and the other is red, the first color layer further comprises a third color area formed from a fourth color material that is yellow, and when excitation light is applied and the excitation light is stopped, the third color area becomes a similar color. Effect of the Invention

[0010] The special luminescent printed matter of the present invention has the effect that the first color region of the first color layer, which is in a complementary color relationship with the fluorescent color when fluorescent light is emitted, is of a similar color to the phosphorescent color, and therefore cannot be recognized when phosphorescent light is emitted; and further, the second color region of the first color layer, which is in a complementary color relationship with the phosphorescent color when phosphorescent light is emitted, is of a similar color to the fluorescent color, and therefore cannot be recognized when fluorescent light is emitted, thereby making it possible to conceal the presence of fluorescence and phosphorescence.

[0011] In addition, when one of the fluorescent color and the phosphorescent color is red and the other is green, the third color region of the first color layer can be made from a fourth color material that is yellow, which has the effect of forming a region that is difficult to recognize both when fluorescent and when phosphorescent are emitted. [Brief description of the drawings]

[0012] [Figure 1] A diagram showing an example of a special light-emitting printed matter (A1) [Diagram 2] A diagram showing an example of the first color layer of a special light-emitting printed matter (A1) [Diagram 3] An example diagram showing the luminous state of the special luminous printed matter (A1) when irradiated with excitation light and when it is turned off. [Figure 4] A diagram showing an example of a special light-emitting printed matter (A2) [Diagram 5] An example diagram showing the luminous state of a special luminous printed matter (A2) when irradiated with excitation light and when turned off. [Figure 6] An example of fluorescent material [Figure 7] An example of complementary color relationships [Figure 8] An example diagram showing the material composition of the embodiment [Figure 9] An example diagram showing the relationship between the first emission color and the second emission color in the third color region. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Next, a description will be given of a form for carrying out the present invention; however, the present invention is not limited to this form, and other embodiments are also included as long as they are within the scope of the technical ideas described in the claims.

[0014] (First embodiment) Fig. 1 shows a special light-emitting printed matter (A1) in the first embodiment. The first embodiment is an example showing a configuration in which the first color layer (2) of the special light-emitting printed layer (6) is in a complementary color relationship with the fluorescent color of the second color layer (5) when irradiated with excitation light, so the fluorescent color is absorbed and the first color region (3) is perceived as darker than the second color layer (5), and the second color region (4) is perceived as darker than the second color layer (5) when irradiation with excitation light is stopped, so the phosphorescent color is absorbed.

[0015] In this specification, the term "complementary color relationship" refers to complementary colors that are opposite each other on the Munsell color wheel, and also includes colors that are close to being opposite each other on the Munsell color wheel, even if they are not exactly opposite each other. For example, the combination of red and green may be used.

[0016] Fig. 1(a) is a plan view of the special light-emitting printed matter (A1), and Fig. 1(b) is an AA' cross-sectional view of the special light-emitting printed matter (A1). As shown in Fig. 1(a) and Fig. 1(b), the special light-emitting printed matter (A1) has a first color layer (2) on a substrate (1) in which a first color area (3) and a second color area (4) are formed adjacent to each other, and a special light-emitting printed layer (6) consisting of a second color layer (5) laminated on the first color layer (2). In addition, the margins of the substrate (1) other than the special light-emitting printed layer (6) may have additional information such as numbers, letters, or photographs.

[0017] In Figure 1, the special light-emitting printed layer (6) is formed on a part of the substrate (1), but it may be formed on the entire substrate (1). Next, another example of the configuration of the special light-emitting printed layer (6) will be explained with reference to Figure 2. Figure 2(a) shows a configuration in which a first color region (3) and a second color region (4) forming a first color layer (2) are formed adjacent to each other. In this specification, "adjacent" means that two adjacent regions are close to each other but not in contact, and "adjacent" means that at least a part of the two adjacent regions is in contact.

[0018] In addition, the special light-emitting printed layer (6) shown in Figures 1 and 2 has a second color layer (5) laminated on top of a first color layer (2), but the first color layer (2) may be laminated as the upper layer and the second color layer (5) as the lower layer, and the order of lamination is not particularly limited.

[0019] (First color layer) The first color layer (2) is composed of a first color region (3) formed by a first color material and a second color region (4) formed by a second color material of a different color from the first color material. The first color material and the second color material are formed using ordinary known inks, inks, and paints (hereinafter referred to as "inks, etc.") that are different in color from each other and do not contain fluorescent materials or phosphorescent materials.

[0020] The color of the first color region (3) in the first color layer (2) is complementary to the emission color of the fluorescent material contained in the second color layer (5) described later and is a similar color to the emission color of the phosphorescent material contained in the second color layer (5). The color of the second color region (4) in the first color layer (2) is complementary to the emission color of the fluorescent material contained in the second color layer (5) described later and is a similar color to the emission color of the phosphorescent material contained in the second color layer (5).

[0021] (similar color) The object color is the color that occurs when light hits an object and is reflected, absorbed, or transmitted, and is expressed by the mixture ratio of the three primary colors cyan, magenta, and yellow. Among them, mixing complementary colors results in an achromatic color (black). In this specification, "similar colors" means colors that are the same or similar to each other, and specifically, the hues of the two colors in the hue circle are within a 90-degree difference range, the saturation of each color in the Munsell hue cross section is within a range of 2 to 14, and the difference in brightness is within a range of ±3, more preferably, the difference in hue is within a 75-degree difference range, and particularly preferably, the difference in hue is within a 60-degree difference range, the saturation is 4 to 14, and the difference in brightness is within a range of ±2. In addition, "black-based" means any hue in the black-based range, and also includes hues such as gray close to black and brown close to black.

[0022] (Second color layer) The second color layer (5) is formed using a third color material containing a fluorescent material having a first emission color when excited by excitation light in a predetermined wavelength range, and a phosphorescent material having a second emission color, which is different from the first emission color, when the excitation light in the predetermined wavelength range is stopped. The object color of the third color material is preferably a transparent ink or the like so as not to mix with the color of the first color layer (2), but may be a colored ink or the like if a coloring material is mixed in such a range that does not affect the first color layer (2). The fluorescent material and phosphorescent material contained in the third color material may be prepared by mixing a plurality of fluorescent materials and phosphorescent materials.

[0023] (Fluorescent materials) The fluorescent material having the first emission color is not particularly limited as long as the fluorescent emission color is visible light, and a known inorganic fluorescent material shown in Fig. 6, which is a general fluorescent material, or a known organic fluorescent material described later can be used. The excitation wavelength range is not particularly limited, but is preferably in the ultraviolet range in view of the versatility of the type of fluorescent material and the light source of the excitation wavelength.

[0024] In addition, examples of organic fluorescent materials include arylamine derivatives, anthracene derivatives (phenylanthracene derivatives, etc.), pentacene derivatives, azole derivatives (oxadiazole derivatives, oxazole derivatives, triazole derivatives, benzoxazole derivatives, benzoazotriazole derivatives, etc.), thiophene derivatives (oligothiophene derivatives, etc.), carbazole derivatives, diene derivatives (cyclopentadiene derivatives, tetraphenylbutadiene derivatives, etc.), distyrylbenzene derivatives, distyrylpyrazine derivatives, distyrylarylene derivatives, stilbene derivatives, silole derivatives, spiro compounds, triphenyl ... Examples of such fluorescent materials and rare earth complexes include triphenylamine derivatives, trifmanylamine derivatives, pyrazoloquinoline derivatives, hydrazone derivatives, pyrazole derivatives, pyrazoline derivatives, pyridine derivatives, pyrrole derivatives (porphyrin derivatives, phthalocyanine derivatives, etc.), fluorene derivatives, phenanthroline derivatives, pyrene derivatives, phenanthrene derivatives, perinone derivatives, perylene derivatives, phenylene compounds, rhodamines, coumarin derivatives, naphthalimide derivatives, benzoxazinone derivatives, quinazolinone derivatives, quinophthalone derivatives, rubrene derivatives, and quinacridone derivatives.

[0025] (Phosphorescent materials) The phosphorescent material having the second luminescent color is a luminescent material that continues to emit light even after the irradiation of the excitation light is stopped, and the duration of the emission (afterglow) is appropriately set, with a shorter afterglow time being better from the viewpoint of concealment, but a longer afterglow time being better from the viewpoint of authentication. Examples of phosphorescent materials include Y2O3:Eu,Mg,Ti, ZnSiO4:Mn, SrAl2O4:Eu,Dy, Sr4Al14O25:Eu,Dy, CaAl2O4:Eu,Nd, Sr2Mg2Si2O7:Eu,Dy, Y2O2S:Eu,Mg,Ti, ZnS:Cu,Mn,Co, CaS:Eu,Tm, etc.

[0026] The substrate (1) is not particularly limited as long as it does not contain a fluorescent material or a phosphorescent material, does not affect the first emission color and the second emission color, and can be printed on the surface, and known paper, plastic, film, cloth, etc. can be used. Examples of the substrate (1) that is paper include fine paper, medium quality paper, lightly coated paper, coated paper, art paper, cast coated paper, kraft paper, synthetic paper, etc.

[0027] The first color layer (2) and the second color layer (5) can be applied to the substrate (1) by generally known intaglio printing, letterpress printing, offset printing, screen printing, gravure printing, flexographic printing, or inkjet printing or by any of various known coating methods. Alternatively, the layers may be applied by a combination of these printing or coating methods.

[0028] The first coloring material, the second coloring material, and the third coloring material are prepared by mixing the above-mentioned materials, thoroughly mixing them with a binder, a builder, etc., and kneading them using a dispersing machine such as a three-roll mill to prepare an ink or coating liquid, and adjusting the viscosity, etc. so that the ink or coating liquid has properties suitable for application to the substrate (1).

[0029] (Lighting state) Figure 3 shows the observation state of the special light-emitting printed matter (A1) in the first embodiment. Figure 3(a) shows the state in which the second color layer (5) of the special light-emitting printed layer (6) of the special light-emitting printed matter (A1) emits fluorescence when irradiated with excitation light. Figure 3(b) shows the state in which the second color layer (5) of the special light-emitting printed layer (6) emits phosphorescence when irradiation with excitation light is stopped.

[0030] As shown in Fig. 3(a), when excitation light is irradiated from an irradiation light source (8), the second color layer (5) emits fluorescence and exhibits a first emission color, and since the color of the first color region (3) and the first emission color are complementary to each other, the first emission color is absorbed by the color material of the first color region (3) and therefore the second color layer (5) is perceived as darker than the second color region (5). On the other hand, the second color region (4) shown by the dotted line is of a similar color to the first emission color, and since the color material of the second color region (4) does not absorb the first emission color, the second color region (5) is perceived as brighter than the first color region (3).

[0031] 3(b), when the irradiation of the excitation light from the irradiation light source (8) is stopped, the second color layer (5) emits phosphorescence and exhibits a second emitted color, and since the color of the second color region (4) and the second emitted color are complementary to each other, the second emitted color is absorbed by the color material of the second color region (4) and is therefore perceived as darker than the second color layer (5). On the other hand, the first color region (3) indicated by the dotted line is of a similar color to the second emitted color, and since the color material of the first color region (3) does not absorb the second emitted color, the first color region (3) is perceived as brighter than the second color region (4).

[0032] Next, a configuration will be described in which a third color region formed of a fourth color material, yellow, which becomes unrecognizable due to the emission colors of both the first emission color and the second emission color when either the first emission color or the second emission color is green and the other is red, is further arranged. Note that a description of the same contents as those of the first embodiment will be omitted.

[0033] Second Embodiment Fig. 4 shows a special luminescent printed matter (A2) in the second embodiment. The second embodiment is an example of a configuration in which, when one of the first and second luminescent colors is green and the other is red, a third color region (7) further disposed on the first color layer (5) is made of a fourth color material that is yellow, and is therefore recognized before irradiation with excitation light but not recognized during fluorescence and phosphorescence after irradiation with excitation light.

[0034] Fig. 4(a) is a plan view of the special light-emitting printed matter (A2), and Fig. 4(b) is an AA' cross-sectional view of the special light-emitting printed matter (A2). As shown in Fig. 4(a) and Fig. 4(b), the special light-emitting printed matter (A2) has a third color area (7) arranged adjacent to the second color area (4) of the first color layer (2). The third color area (7) is formed in an arrangement adjacent to or adjacent to at least one of the first color area (3) or the second color area (4).

[0035] The above-mentioned yellow range is defined as a hue in which yellow with a hue angle (h) in the range of 78.55 degrees to 101.87 degrees is difficult to recognize in both fluorescence and phosphorescence, when the PANTONE (registered trademark) color sample book "PANTONE SOLID CHIPS UNCOATED" is measured using a Spectroeye spectrophotometer (manufactured by Gretag Macbeth) under conditions of light source D65, field of view 10 degrees, and absolute white standard. The fourth coloring material, which is yellow, can be a known ink or the like within the above-mentioned range. Next, the reason why the third color region (7) cannot be recognized when it is formed by yellow will be explained with reference to FIG. 9.

[0036] Fig. 9 shows the results of measuring the color of the yellow base print using a SpectroEye spectrophotometer (manufactured by Gretag Macbeth), measuring the red fluorescence and green phosphorescence using a fluorescence spectrophotometer, and normalizing the measured values. As shown in Fig. 9, at least a part of the reflection wavelength range in the spectral reflectance spectrum of the red fluorescence, which is the first emission color, and the green phosphorescence, which is the second emission color, overlaps with the spectral reflectance spectrum of the yellow, which is the fourth coloring material (reflectance 0.7 to 0.8), and yellow, which has a reflectance almost close to that of red and green, is difficult to distinguish with the naked eye.

[0037] (Lighting state) Figure 5 shows the observation state of the special light-emitting printed matter (A2) in the second embodiment. Figure 5(a) shows the state in which the second color layer (5) of the special light-emitting printed layer (6) emits fluorescence when ultraviolet light, which is excitation light, is irradiated from the irradiation light source (8) onto the special light-emitting printed matter (A2). Figure 5(b) shows the state in which the second color layer (5) of the special light-emitting printed layer (6) emits phosphorescence when the irradiation from the irradiation light source (8) is stopped.

[0038] In the special light-emitting printed matter (A2) of the second embodiment, as shown in FIG. 5(b), phosphorescence is emitted by stopping the irradiation of the excitation light from the irradiation light source (8), and the second color region (4) is perceived as darker than the second color layer (5) because it is a complementary color to the phosphorescent color, and the first color region (3) shown by the dotted line is perceived as brighter than the second color region (4) because it is a similar color to the phosphorescent color. Furthermore, the third color region (7) shown by the dotted line is made of a fourth color material that is yellow and has at least a part of the reflection wavelength range in the spectral reflection spectrum overlapping with the phosphorescent color of the third color material, so that it has the effect of not being recognized when it fluoresces or phosphoresces after irradiation with excitation light. According to this, the third color region (7) cannot be recognized even when it fluoresces or phosphoresces, and the counterfeiting prevention effect can be further improved. EXAMPLES

[0039] Next, examples of the present invention will be described, but the embodiments of the present invention are not limited to these examples.

[0040] Example 1 As Example 1, a special light-emitting printed matter (A1) will be described with reference to Figs. 1 and 3 in the same manner as in the first embodiment.

[0041] In the first color region (3) constituting the first color layer (2), a green offset ink (UV L-LESP177C, manufactured by T&K TOKA Co., Ltd.) was used as the first coloring material, and in the second color region (4), a red offset ink (UV L-LESKP360C, manufactured by T&K TOKA Co., Ltd.) was used as the second coloring material. The substrate (1) was a general high-quality paper (Shiraoi, Nippon Paper Industries Co., Ltd.).

[0042] The second color layer (5) uses a red fluorescent material (Lumilux Red CD777, manufactured by Honeywell Corporation) that emits fluorescence when exposed to ultraviolet light as a first emission color, and a green phosphorescent material (GLLH, manufactured by Nemoto Specialty Chemicals Corporation) that emits phosphorescence when exposed to ultraviolet light as a second emission color. The mixture was adjusted to the mixing ratio shown in Figure 8 and mixed in a Huber Maler to prepare a screen ink as a third color material.

[0043] Next, using a small offset printing machine for hand printing, a first color area (3) was printed with a first coloring material to form a green letter "P," and a second color area (4) was printed with a second coloring material to form a red letter "B" adjacent to the letter "P" in the first color area (3) on the base material (1), thereby forming a first color layer (2).

[0044] Next, a second color layer (5) was printed on top of the first color layer (2) using a hand-operated screen printing machine using a third color material to form a special luminescent printed layer (6), thereby producing the special luminescent printed matter (A1) shown in Figure 1.

[0045] Next, since the irradiation light source (8) uses ultraviolet light as excitation light, a UVLamp (UVGL-58 Handheld, manufactured by Funakoshi Co., Ltd.) was used to irradiate the special luminescent printed matter (A1) with ultraviolet light having a wavelength of 254 nm.

[0046] As shown in FIG. 3(a), when ultraviolet light irradiation is stopped, the letter "P" is perceived as darker than the second color layer (5) because the green letter "P" in the first color area (3) and the first red luminous color of the second color layer (5) are complementary colors. On the other hand, the letter "B" is perceived as brighter than the green letter "P" in the first color area (3) because the red letter "B" in the second color area (4) and the first red luminous color of the second color layer (5) are similar colors. Also, as shown in FIG. 3(b), when ultraviolet light irradiation is stopped, the letter "B" is perceived as darker than the second color layer (5) because the red letter "B" in the second color area (4) and the second green luminous color of the second color layer (5) are complementary colors. On the other hand, since the green letter “P” in the first color area (3) and the green second luminous color are similar colors, the letter “P” was recognized as brighter than the red letter “B” in the second color area (4).

[0047] Example 2 As a second embodiment, a special light-emitting printed matter (A2) will be described with reference to Figs.

[0048] The first color region (3) and the second color region (4) constituting the first color layer (2), the second color layer (5), and the base material (1) were made of the same materials as those in the above-mentioned Example 1. The third color region (7) used a yellow offset ink (yellow ink for H-UV L (manufactured by KOMORI Co., Ltd.)) as a fourth coloring material.

[0049] Next, similarly to Example 1, a small offset printing machine for hand printing was used to print the first color area (3) and the second color area (4), and a yellow letter "C" was printed using a fourth coloring material as a third color area (7) adjacent to the second color area (4) to form a first color layer (2).

[0050] Furthermore, similar to Example 1, a hand-printed screen printer was used to print a second color layer (5) on top of the first color layer (2) using a third color material to form a special luminescent printed layer (6), thereby producing the special luminescent printed matter (A2) shown in Figure 4.

[0051] Next, using the same irradiation light source (8) as in Example 1, the special light-emitting printed matter (A2) was irradiated with ultraviolet light having a wavelength of 254 nm.

[0052] As shown in FIG. 5(a), when ultraviolet light is applied, the green letter "P" in the first color region (3) and the first red luminous color of the second color layer (5) are complementary colors, so the letter "P" is perceived as darker than the second color layer (5). On the other hand, the red letter "B" in the second color region (4) and the first red luminous color are similar colors, so the letter "B" is perceived as brighter than the green letter "P" in the first color region (3). Also, as shown in FIG. 5(b), when the ultraviolet light application is stopped, the red letter "B" in the second color region (4) and the second green luminous color of the second color layer (5) are complementary colors, so the letter "B" is perceived as darker than the second color layer (5). On the other hand, the green letter "P" in the first color region (3) and the second green luminous color are similar colors, so the letter "B" is perceived as brighter than the red letter "B" in the second color region (4). As shown in Figures 5(a) and 5(b), the letter "C" in the third color area (7) could not be recognized either when ultraviolet light was being irradiated or when ultraviolet light irradiation was stopped. [Explanation of symbols]

[0053] A1 Special luminous print A2 special luminous print 1 Base material 2. The first color layer 3. The First Color Region 4. The Second Color Region 5. The second layer of color 6 Special light-emitting printing layer 7. The Third Color Region 8 Irradiation light source

Claims

1. A special light-emitting printed layer is provided on at least a portion of a substrate, the special light-emitting printed layer being composed of a first color layer and a second color layer laminated on the first color layer; the first color layer is configured by arranging a first color region formed by a first color material and a second color region formed by a second color material having a color different from that of the first color material; the second color layer is formed of a fluorescent material having a first emission color which is complementary to the first color material and similar to the second color material when excited by excitation light in a predetermined wavelength range, and a third color material containing a phosphorescent material having a second emission color which is complementary to the first color material and similar to the second color material after the excitation light is stopped, A special luminescent printed matter characterized in that, when the excitation light is irradiated onto the special luminescent printed layer, the first color region absorbs the first luminescent color and appears dark, and the second color region does not absorb the first luminescent color and appears bright, and when the excitation light is stopped, the second color region absorbs the second luminescent color and appears dark, and the first color region does not absorb the second luminescent color and appears bright.

2. A special luminous printed matter as described in claim 1, characterized in that when one of the first luminous color and the second luminous color is green and the other is red, the first color layer further comprises a third color area formed from a fourth color material that is yellow, and when the excitation light is irradiated and when the excitation light is stopped, the third color area becomes a similar color.

Images