JP2008214783A - Thread and anti-counterfeit paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-counterfeit material facilitating discrimination between true or false without using any special tool or device and having a high anti-counterfeit effect. <P>SOLUTION: This thread provided with a coated layer changing its hue by changing temperature on a base member is produced. Thereby, it becomes possible to distinguish the color-changing effect of the thread with the change of temperature by viewing, and easily discriminate the true or false. By incorporating the thread in paper, it is possible to prepare the paper used for anti-counterfeit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thread having an authenticity determination function and anti-counterfeit paper. More specifically, the present invention relates to a thread that can easily and highly determine authenticity by changing to a completely different hue according to a change in temperature, and a forgery prevention sheet using the thread.

Securities with a monetary value such as banknotes, gift certificates, stock certificates, bonds, checks, lotteries, etc. have various anti-counterfeiting measures so that they are not easily counterfeited or altered.

Due to recent technological advances, the above-mentioned securities are printed by a multicolor printer, copied by a color copier, or captured by a scanner linked to a personal computer and printed by a color printer. Forgery is increasing in many ways. Recently, even for home printers, it has become possible to produce counterfeit products relatively easily because the resolution, hue, and the like can be reproduced so precisely that they cannot be distinguished from the real ones. Thus, counterfeiting using digital devices has become a problem, and the damage caused by the counterfeiting has become familiar.

From the background as described above, various proposals have been made as techniques for preventing counterfeiting using digital devices. For example, Patent Document 1 proposes an anti-counterfeit paper in which a thread coated with a pearl pigment is drawn. Patent Document 2 proposes a thread combining a metameric phenomenon and a pearly luster layer. Patent Document 3 proposes a security element with a hologram, and other proposals include pearl pigment printing, ultraviolet fluorescent printing, and anti-counterfeit paper that is processed as a thread and used as a thread. ing.

Holograms and pearl pigments have metallic luster and pearl luster, and glossiness cannot be reproduced by printing with a color copier or by outputting an image read with a digital scanner linked to a personal computer with a color printer. Therefore, there is an effect of preventing forgery. For example, in the case of Patent Document 4, the present applicant forms a partial coating layer mainly composed of a pearl pigment and an adhesive on the surface of a base paper to obtain a forgery-preventing paper. Proposed to get prevention printed matter.

However, even if we establish anti-counterfeiting technology, new anti-counterfeiting means are being created one after another, so new anti-counterfeiting technology is always in demand to counter new emerging counterfeiting means. It has been. Furthermore, as a result of being easily counterfeited by a method using a printing machine, scanner, etc. as described above, the damage caused by the counterfeit is also familiar, so that forgery can be easily determined without using special equipment. There is a need for a technology that enables prevention techniques to determine authenticity. For example, in a store where a gift certificate or the like is purchased, there is a demand for a technique that allows the store clerk to easily determine the authenticity of the gift certificate that has been brought in on the spot.

JP-A-7-56377 JP 2003-306897 A JP 2006-528369 A JP-A-6-313298

  In order to perform simple authentication, it is desirable not to use a special instrument such as a black light or a magnetic detection device, and a security material that can easily determine authentication is effective. It is an object of the present invention to provide a forgery prevention technique effective for such means.

  As a result of earnest research on the above-mentioned problems, the present invention has been completed by applying a coating layer whose hue changes with temperature to the threads. Further, by imparting other functions to be described later, it is possible to obtain a high forgery prevention effect, and further, by embedding the thread on paper, it is possible to obtain an anti-counterfeit paper that has never existed.

That is, the invention according to claim 1 of the present invention is a thread characterized by having a temperature-responsive coating layer whose hue changes as the temperature changes on at least one surface of the substrate.

The invention according to claim 2 of the present invention is the thread according to claim 1, wherein the hue of the temperature-responsive coating layer reversibly changes as the temperature changes.

The invention according to claim 3 of the present invention is the thread according to claim 1 or 2, wherein the base material is a transparent multilayer film having pearl luster.

  The invention according to claim 4 of the present invention is the thread according to claim 1 or 2, wherein the thread has a pearly luster layer on the surface of the substrate.

The invention according to claim 5 of the present invention is the thread according to any one of claims 1 to 4, wherein an ultraviolet absorbing layer is provided.

The invention according to claim 6 of the present invention is the thread according to any one of claims 1 to 5, wherein the temperature at which the hue changes is −4 ° C. to 58 ° C.

The invention according to claim 7 of the present invention is the thread according to any one of claims 1 to 5, wherein the temperature at which the hue changes is 25 ° C. to 33 ° C.

The invention according to claim 8 of the present invention exhibits the same hue at room temperature, but two or more types of heat change coating layers having different hues after heat change form an arbitrary pattern on the substrate surface. It is a thread | sled of Claims 1-7 characterized by these.

The invention according to claim 9 of the present invention exhibits two different hues at room temperature, but two or more types of temperature-responsive coating layers having the same hue after heat change form a ground pattern on the substrate surface. The thread according to claim 1, wherein the thread is a thing.

The invention according to claim 10 of the present invention is the thread according to claims 1 to 9, wherein micro characters are printed on the surface of the base material.

The invention according to an eleventh aspect of the present invention is the thread according to the tenth aspect, wherein the hue of the micro characters reversibly changes as the temperature changes.

The invention according to claim 12 of the present invention is such that the micro characters have the same color as the temperature-responsive coating layer under room temperature conditions, and the temperature-responsive coating layer under temperature conditions other than room temperature. The thread according to claim 11, wherein the thread changes to a different hue.

According to a thirteenth aspect of the present invention, the micro characters are composed of an ink composed of a pigment component that absorbs infrared rays and a binder, and the infrared characters of the micro characters and the temperature-responsive coating layer under room temperature conditions. The thread according to claim 10, wherein spectral reflectances in the regions are different.

The invention according to claim 14 of the present invention is a forgery-preventing paper, wherein the thread according to any one of claims 1 to 13 is embedded in paper.

The invention according to claim 15 of the present invention is the anti-counterfeit paper according to claim 14, wherein the thread is intermittently exposed on the paper surface.

The anti-counterfeit paper or sheet-like material using the thread according to the present invention has the effects described below, and measures for preventing forgery of banknotes, gift certificates, passports, stock certificates, identification cards, cards, admission tickets, stock certificates, checks, etc. Can be preferably used.
(1) It is possible to easily determine the authenticity of the color change effect of the thread due to a change in temperature by visual observation.
(2) The thread having pearly luster has a color shift effect in which the hue continuously changes depending on the viewing angle under visible light, and it can be easily determined by visual inspection.
(3) The effects of (1) and (2) can be confirmed at the same time, and since no special technical instrument is required for this detection, authentication can be easily determined.
(4) Furthermore, forgery can be made difficult by adding micro characters.

The first embodiment of the present invention is a thread in which a temperature-responsive coating layer whose hue changes with changes in temperature is provided on at least one surface of a substrate. Since the hue of the thread changes due to a change in temperature condition, the authenticity can be determined visually. For example, if the design is such that when the thread is touched with a finger, the hue of the thread changes in response to the heat of the body temperature, anyone can easily identify the authenticity determination.

Materials used for the temperature-responsive coating layer of the present invention include conventionally known electron-donating color-forming organic compounds, compounds having a phenolic hydroxyl group, alcohols, ethers, esters, and ketones. It is a thermochromic material consisting of three components with an organic solvent selected from either. Electron-donating color-forming organic compounds include, for example, diphenylmethane phthalides, triphenylmethane phthalides, phenyl indolyl phthalides, indolyl phthalides, diphenyl methane azaphthalides, phenyl indolyl azaphthalides, Fluorans, stylinoquinones, azomethines, leucooramines, spiropyrans, rhodamine lactams, diazarhodamine lactones, naphtholactams, phenothiazines, triazenes, spirophthalanthanthenes is not. Examples of the compound having a phenolic hydroxyl group include monophenols and polyphenols, and specific examples thereof include those described in JP-A-49-78682 and JP-A-61-9488. It is not limited to these.

As the thermochromic material, for example, a material encapsulated in a microcapsule having a particle size of 0.1 to 50 μm is preferably used. There are three types of color change depending on the temperature of the thermochromic material: one that changes reversibly, one that changes quasi-reversibly, and one that changes irreversibly, depending on the material selected. .

In addition to the thermochromic material, the paint forming the temperature-responsive coating layer includes a melamine resin, urea resin, phenol resin, alkyd resin, petroleum resin, polyester resin, polyurethane resin, polyvinyl chloride resin as a binder, Polyvinyl acetate resin, polyamide resin, polyacrylic ester resin, nitrocellulose, cyclized rubber, chlorinated rubber, etc. can be used alone or as a mixture, and the binder is toluene, ethyl acetate, methyl ethyl ketone, acetone, gasoline, etc. It is used by dissolving in an organic solvent such as petroleum solvent. Other binders include rosin-modified phenolic resins dissolved in drying oils (linseed oil, etc.) and high-boiling solvents for offset printing ink vehicles, or SBR latex, MBR latex, vinyl acetate emulsion, acrylic acid. Water-based binders such as ester emulsions and polyvinyl alcohol resins can be used.

Examples of changes in the hue of the temperature-responsive coating layer include the following. One is colored below the temperature at which the hue changes, and changes to white when the hue change temperature is exceeded. Specifically, there are those that change from black to white, and those that change from blue to white. . As another, there are things that are colored below the hue change temperature and change to a color different from the original hue when the hue change temperature is exceeded, specifically those that change from black to blue, green to yellow There are things that change. Of course, other hue changes can be designed. The design of the hue change has a wide selectivity depending on the selection of the developer and the combination with the colored dye and / or the pigment, and can be appropriately selected and used according to the purpose.

Moreover, it is preferable that a temperature-responsive coating layer changes reversibly with changes in temperature. This is because even if the hue has changed once, it can be used repeatedly as long as it can return to the original hue.

A general film is used as the substrate used in the present invention. For example, films of PET, polyester, polyethylene, polypropylene, cellophane, nylon, polyvinyl alcohol, polyvinyl chloride, polycarbonate, etc. are used, but are not limited thereto.

The method of providing the temperature-responsive coating layer on the substrate can be performed using a known coating technique. Examples of the coating method include, but are not limited to, a rod coater, a bar coater, an air knife coater, a blade coater, a gravure coater, a die coater, and a gate roll coater.

In addition, a thread | sled is obtained by slit-processing the base material which has a temperature-responsive coating layer. The slit processing is performed by slitting to a predetermined width using a known apparatus such as a micro slitter.

Moreover, in this invention, since the higher forgery prevention effect can be acquired when using the transparent multilayer film which has a pearl luster for a base material, it is preferable. In this way, it is possible to combine both the color shift effect under reflected light and the effect of hue change due to temperature change, making it difficult to forge the complex change. The color shift effect means that the color changes as the reflected light gradually shifts when the viewing angle with the object is changed.

The transparent multilayer film used in the present invention is a film obtained by laminating a plurality of polymers having two or more different refractive indexes, and exhibits a pearly luster due to a light interference phenomenon. For example, a polymer obtained by repeatedly laminating 100 or more layers of a high refractive index and a low refractive index can be used. It is known that pearl luster cannot be reproduced by a copying method such as color copying or reading with a digital scanner and outputting with a printer because it has the characteristic of shining in an iris color when viewed with specular reflection light. Therefore, by using the transparent multilayer film, not only a color shift effect but also such a copy prevention effect can be imparted. Furthermore, when the colored coating layer provided on the transparent multilayer film having pearly luster is viewed through the film, a new hue in which the original hue of the film is mixed is generated. As described above, in the present invention, since the hue of the colored coating layer also changes due to temperature change, the color shift effect becomes very complicated, and as a result, a high anti-counterfeit effect can be obtained.

In the present invention, a color shift effect can also be obtained by providing a coating layer having a pearly luster on the thread base material. Therefore, the same forgery prevention effect as that obtained when the transparent multilayer film is used is obtained. be able to. When the transparent multilayer film having the pearly luster described above is used, the hue changes depending on each layer and the total thickness, so there is a concern in terms of cost in production in a small lot, but a coating layer having a pearly luster is provided. The method also has the advantage that a wide variety of variations can be achieved by changing the pigment at a lower cost than film production.

Examples of pigments that can be used in the coating layer having pearly luster include natural pearl essence, mica powder, basic carbonate, titanium oxide-coated mica powder, metal oxide-coated mica powder, and Bengala-coated mica. The method for producing such a pearl pigment is not particularly limited, and conventionally known production methods (for example, Japanese Patent Publication Nos. 53-47375, 54-34010, 58-149959, etc.) Can be used.

The pearl pigment is mixed with an adhesive and applied to the substrate. The adhesive is not particularly limited as long as the pearl pigment can be fixed to the base material. For example, an aqueous dispersion of binder particles combined with an ultrafine filler can be used. Colloidal silica, alumina sol, etc. can be used as ultrafine fillers, and acrylic polymer emulsion, silane group addition olefin polymer emulsion, polyvinyl alcohol, modified polyvinyl alcohol, ethylene-vinyl acetate copolymer emulsion, etc. as binders. Can be used. The coating layer having pearly luster can be provided by using a known coating technique as described above.

In the present invention, a resin layer having ultraviolet absorbing ability can be provided on the substrate. By providing this, it is possible to improve the light resistance of the material used for the temperature-responsive coating layer, so that it can be suitably used even when used in such a way that it is distributed or stored for a long period of time. it can. In order to prevent the photo-degradation of the temperature-responsive coating layer, the resin layer having the UV-absorbing ability is preferably used so that the UV-absorbing layer is present on the side exposed to light from the temperature-responsive coating layer. . For example, as shown in FIG. 1, the three ultraviolet absorbing layer, the two-temperature reactive coating layer, and the base material are used in this order from the light-receiving side. Or it is good to use like FIG.2 and FIG.3 also in another structure.

As the resin used for the resin layer having ultraviolet absorbing ability, a known resin can be used. In particular, transparent resins such as benzophenone, benzotriazole, and benzoate are preferably used. The reason is that the ultraviolet absorbing layer is functionally disposed on the side that is exposed to light rather than the temperature-responsive coating layer. Therefore, it is not preferable to use a material such as titanium oxide that imparts opaqueness at the same time as the ability to absorb ultraviolet rays because it may hinder the visibility of the hue change effect.

In the present invention, the temperature at which the hue of the material used for the temperature-responsive coating layer changes is preferably in the range of −4 ° C. to 58 ° C. And it is preferable to set the change temperature to 25-33 degreeC especially. By using a material that falls within this temperature range, it is possible to change the hue even at a human body temperature, so it is possible to easily determine the authenticity without requiring a special device such as a cooling device or a heating device. . When the hue change temperature is less than 25 ° C., it is necessary to use some cooling means in order to confirm the hue change in the season when the air temperature is 25 ° C. or higher. In that case, it may be cooled using a simple object such as a cooling spray, a cooling sheet, an ice pack, or a cooling machine. However, if the hue change temperature is less than −4 ° C., a special cooling device is required, and as a result, it is not possible to easily determine the authenticity. Further, when the hue change temperature is higher than 33 ° C., it is difficult to change at about the surface temperature of a human hand, so some heating means is required. At this time, it is preferable to use simple means as much as possible. For example, a change in hue can be confirmed by using a heater, a heater, a warmer, heat of a fluorescent lamp, a hot water bottle, a thermal sheet, or the like. However, if the hue change temperature is higher than 58 ° C., a special heating device is required, and it may not be possible to easily perform authentication determination, which is not preferable.

In the present invention, two or more types of temperature-responsive coating layers may be provided. By providing two or more types of temperature-responsive coating layers on the substrate surface so as to form an arbitrary pattern, it is possible to give a more complex hue change and enhance the forgery prevention effect, which is preferable. For example, two or more types of heat change coating layers that exhibit the same hue at room temperature but have different hues after the temperature change are arranged on the substrate so as to form stripes or tints, so that the same color at room temperature. However, it is only possible to check the stripe or background pattern by changing the temperature. In this way, not only the hue changes but also various design properties can be given depending on the type of pattern. For this reason, since it is possible to give unique characteristics according to the application and user, it is possible to obtain a thread that is highly practical and has a high anti-counterfeit effect.

In addition, two or more types of temperature-responsive coating layers that exhibit different hues at room temperature but exhibit the same hue after heat change can be confirmed at room temperature by arranging them on the substrate to form an arbitrary pattern. The effect is that the pattern becomes invisible after a temperature change. This is also effective as an anti-counterfeit measure, and as described above, by providing the pattern with features, a further excellent practicality and a high anti-counterfeit effect can be obtained.

A micro character can be given to the thread of the present invention. As a configuration in the case of providing a micro character, for example, there is a configuration in which the micro character is printed on a substrate and then covered with a temperature-responsive coating layer. Or the structure which provides a micro character after providing a temperature-reactive coating layer on a base material is mentioned. There is no particular limitation on the method for printing micro characters, but gravure printing and screen printing are suitable. As the ink used for the micro characters, known inks can be used.

In addition, the hue is the same as that of the temperature-responsive coating layer under room temperature conditions, but even more advanced by applying micro letters having a color that does not have temperature-responsiveness even when the temperature changes to a temperature other than room temperature. An anti-counterfeit effect can be obtained. This is because micro characters cannot be read under room temperature conditions, but a feature that makes it possible to read the micro characters by changing the hue due to temperature change can be provided. In addition, since advanced printing technology is required to reproduce the micro characters, it is suitable for giving highly unique information such as a company name and personal name as micro characters.

Furthermore, two or more types of micro characters may be provided in the thread of the present invention. For example, in addition to the micro letters having the same hue as the temperature-responsive coating layer under the room temperature conditions (hereinafter referred to as “micro letter A”), the hue different from that of the temperature-responsive coating layer is exhibited under the room temperature conditions. However, a micro character having a color that is the same as the hue that the coating layer shows after the temperature change (hereinafter referred to as “micro character B”) is provided. In this way, only the micro letter B can be read at room temperature, but if the hue of the temperature-responsive coating layer changes due to a temperature change, the micro letter B disappears and the micro letter A can be read instead. In this way, by selecting a plurality of micro characters according to the hue of the temperature-responsive coating layer, a variety of anti-counterfeiting effects can be obtained.

It should be noted that a higher anti-counterfeiting effect can be imparted by using a pigment having infrared absorptivity such as carbon black for the ink used for the above-mentioned micro characters. This will be explained in detail. Under the reflected light, the hue of the micro characters is assimilated with the temperature-responsive coating layer at room temperature, but the micro characters cannot be read under infrared light. Can be read. Even if there is no temperature change, it is possible to determine the authenticity. In other words, by using infrared absorbing ink for the micro characters, in addition to the above-described effect that the micro characters can be read by the hue change due to the temperature change, it is possible to determine the authenticity by the infrared camera or the like even at the room temperature. It can be done.

The pigment having infrared absorptivity is not limited to carbon black, and is not particularly limited as long as the pigment has similar performance. A material that hardly absorbs light in the visible light region and has a maximum absorption peak in the infrared light region is preferably used. For example, a pigment containing metal oxide, iron, nickel, cobalt, chromium, copper, vanadium, zirconium, titanium, ruthenium, platinum, a phthalocyanine pigment, a naphthalocyanine pigment, an azo pigment, and the like can be given.

According to a second aspect of the present invention, there is provided a forgery prevention paper in which the thread of claims 1 to 13 is inserted into the paper. For example, when the thread is inserted into the paper, unlike the case where the thread is buried from the surface of the paper by bonding, peeling between the layers in which the thread is inserted becomes difficult, and the thread is difficult to fall off. In addition, there is an effect of preventing a malicious person from peeling off and diverting the thread. Even if the thread is in the paper, the change in hue can be used without any problem if it can be easily identified.

As a method of making the thread into the paper, the nozzle is inserted into the flow of the stock in the slice part of the long paper machine, and the thread is fed out while flowing water through the nozzle, and the paper is formed in the paper web formed on the paper web. A method of making a thread (Japanese Patent Laid-Open No. 51-130309), installing a thread insertion device into the stock flowing out of the flow box of a long paper machine, and making the thread and the stock non-contact with an air flow While making a thread (Japanese Patent Laid-Open No. 2-169790), using a multi-layer type circular paper machine, the thread is made by using a pipe having irregularities on the inner wall by making two or more layers. For example, a method of sending out between paper layers and forming a thread between paper layers (Japanese Patent Publication No. 5-40080) can be used.

In addition, when the thread of the present invention is made into paper, the thread may be intermittently exposed on the paper surface. More specifically, a window opening portion having a thickness that is intermittently reduced is formed on the surface of the paper, and a thread is exposed in the window opening portion. The paper produced in this way is called a so-called “window opening thread paper”, and the portion where the thread is exposed has an advantage that it is easier to judge the hue change and to read the micro characters.

As a method for producing the window-open thread paper, a method of manufacturing a paper suspension on a wire by burying a belt mechanism having a groove through which a thread is passed at the tip of a convex portion of a guide having a concave-convex portion (special feature). No. 5-85680) and a method of using a mesh processed into a concavo-convex shape for the upper screen of a circular paper machine and inserting the thread while making contact with the concavo-convex portion on the surface of the net to make the thread into the window opening portion. (US Pat. No. 4,462,866), or a compressed air nozzle is built in a rotating drum on the wire of a long paper machine, and the slurry on the thread previously inserted into the web is blown off intermittently with compressed air. And a method of exposing (JP-A-6-272200).

In the present invention, there is no particular limitation on the raw material of the paper to be threaded, but it is beaten by appropriately blending non-wood pulp such as wood pulp, hemp, cotton, straw, etc. What mixed the fiber, the inorganic fiber, etc. can be used. A filler is prepared by appropriately adding a filler, a paper strength enhancer, a sizing agent, a fixing agent, a yield improver, a drainage improver, an antifoaming agent, a dye, and a pigment.

[Example 1]
A transparent PET film (trade name “Lumirror”, manufactured by Toray Industries, Inc.) with a thickness of 16 μm is used as a substrate, and a temperature gravure ink (trade name “chromi color black to white” temperature type is used as a temperature-responsive coating layer. 27 "" (manufactured by Matsui Dye Chemical Co., Ltd.) with a gravure coater, a film obtained by applying 8 g / m ² was slit to a width of 2.5 mm to obtain a thread. The thread thus obtained had a black color at room temperature set at 25 ° C., the hue changed when it was raised to 27 ° C., and turned gray when it was raised to 30 ° C. When the temperature was returned from 30 ° C. to 25 ° C., the original black color was restored in about 20 seconds.

[Example 2]
A transparent multilayer film (trade name “MLF”, manufactured by Teijin DuPont Co., Ltd.) having a pearly luster with a thickness of 16 μm is used as a base material, and a temperature gravure ink (trade name “chromicolor black” is used as a temperature-responsive coating layer. to white “Temperature Type 27”) was applied with a gravure coater at 8 g / m ^2, and a slit was formed into a width of 2.5 mm to obtain a thread. The resulting thread had a black temperature-responsive coating layer under the condition of 25 ° C., and when viewed from the film surface side, the color shift effect of changing from green to red depending on the angle was clearly visible. When the temperature was raised to 30 ° C., the temperature-responsive coating layer turned white, and the original pink color of the film could be seen. Although the original effect of the film did not change, the hue on the back side changed, so that the hue and effect of the film itself seemed to change, and a unique design could be obtained. When the temperature was returned from 30 ° C. to 25 ° C., the temperature-responsive coating layer returned to black.

[Example 3]
A urethane resin binder (trade name “RAMIC F220”, manufactured by Dainichi Seika Kogyo Co., Ltd.) was diluted to a solid content of 15%. A pearl pigment (trade name “Iriodin”, manufactured by Merck & Co., Inc.) was added to this solution to make a total solid content of 25%, and a coating material was prepared by dispersing. This paint was applied to a transparent PET film (trade name “Lumirror”) having a thickness of 16 μm with a gravure coater at 10 g / m ² to prepare a film having a pearly luster layer. Subsequently, a film obtained by applying 8 g / m ² with a gravure coater so as to cover this pearly luster layer (trade name “Chromi Color Black to White“ Temperature Type 27 ”) is slit to a width of 2.5 mm. Processed to get a thread. The resulting thread had a black temperature-responsive coating layer under 25 ° C. conditions, and when viewed from the film surface side, the blue pearly luster was clearly visible. When the temperature was raised to 30 ° C., the temperature-responsive coating layer turned white. At first glance, the thread looked white, but depending on the angle, blue pearl luster could be confirmed. Although the hue of the pearly luster layer did not change, it utilized the characteristic that the pearly luster was conspicuous when the lightness of the hue on the back surface was low, and a unique design could be obtained. When the temperature was returned again from 30 ° C. to 25 ° C., the temperature-responsive coating layer returned to black, and the thread showed a blue pearl luster.

[Example 4]
From the temperature-responsive coating layer side of the film obtained in Example 2, 1 g of a resin (trade name “ULS-1935”, manufactured by Yushi Kogyo Co., Ltd.) having ultraviolet absorbing performance was obtained with a gravure coater. After coating / m ² , this was slit to a width of 2.5 mm to obtain a thread.

Both the threads obtained in Example 2 and Example 4 were subjected to a light resistance tester (named?), And irradiated with ultraviolet rays continuously. The thread obtained in Example 2 had a black color at 25 ° C. before the test, but when irradiated with ultraviolet rays for 6 hours, the temperature-responsive coating layer turned gray, and the irradiation for 17 hours was performed. It turned completely white and did not return to black when the irradiation was stopped. On the other hand, the thread obtained in Example 4 had a black color at 25 ° C. before the test, but its hue (black) did not change even after 6 hours of ultraviolet irradiation, and its function was It was not lost. After 17 hours of irradiation, the hue of the temperature-responsive coating layer changed to gray, and it took 35 hours of ultraviolet irradiation until it completely turned white and did not return to black. This confirmed that the thread of Example 4 had improved resistance to ultraviolet rays.

[Example 5]
A transparent multi-layer film (trade name “MLF”) having a pearly luster with a thickness of 16 μm is prepared as a base material, and a temperature gravure ink (trade name “chromi color black to pink“ temperature type 27 ””, Matsui Co., Ltd. A stripe pattern was printed using a dye chemical industry). Further, a temperature gravure ink (trade name “Chrome Color Black to White“ Temperature Type 27 ”) was applied to the entire surface so as to cover the stripe pattern, thereby forming a temperature-responsive coating layer. A thread was obtained by slitting to 5 mm, and the thread thus obtained was black in the temperature-responsive coating layer under the condition of 25 ° C. The stripe pattern could not be seen. The color shift effect that changes from green to red depending on the angle was conspicuous, and when the temperature was raised to 30 ° C, blue and white stripe patterns emerged. The blue part of the film, together with the pink part of the film, appeared purple, and this caused the pattern to emerge as the temperature changed. It was confirmed that the film was obtained.

[Example 6]
A transparent multi-layer film (trade name “MLF”) having a pearly luster with a thickness of 16 μm is prepared as a base material, and a temperature gravure ink (trade name “Chrome Color Newborn to White“ Temperature Type 27 ””, Co., Ltd. A stripe pattern was printed using Matsui Dye Chemical Co., Ltd.). Furthermore, temperature gravure ink (trade name “Chrome Color Fast Blue to White“ Temperature Type 27 ”, manufactured by Matsui Dye Chemical Co., Ltd.) is applied over the entire surface to cover this stripe pattern, and temperature responsive coating is applied. A construction layer was formed. This was slit to a width of 2.5 mm to obtain a thread. The resulting thread has a stripe pattern in which the color shift effect that changes from green to red when viewed from the film surface at 25 ° C and the color shift effect that changes from blue to purple form a stripe pattern. It was. When this was placed at 30 ° C., any temperature-responsive coating layer turned white, and the original pink color of the film could be seen.

[Example 7]
A transparent PET film (trade name “Lumirror”) with a thickness of 16 μm is prepared as a base material, and after printing micro characters using a carbon black pigment ink on a rotary screen printing machine, the micro characters are covered. A temperature gravure ink (trade name “chromi color black to white“ temperature type 27 ”) was applied at 10 g / m ² over the entire surface to form a temperature-responsive coating layer. This was slit to a width of 2.5 mm to obtain a thread. The thread thus obtained was only black under 25 ° C. conditions, and the micro characters could not be confirmed. However, when the temperature was raised to 30 ° C., the carbon black pigment portion was left and the color changed to white, and the printed micro characters could be read.

In addition, the thread obtained in Example 7 appeared only black under visible light at 25 ° C., but when this was photographed with a camera capable of irradiating infrared rays and sensing infrared rays, only the carbon black pigment portion was infrared rays. It was possible to read the micro characters. As a comparative example, instead of using the carbon black pigment ink in Example 7, micro characters were printed using a mixed color black ink having no infrared absorbing ability, and the micro character printing portion of the obtained thread transmitted infrared rays. Therefore, even if the camera was used under infrared irradiation, it was not possible to read micro characters.

[Example 8]
<Preparation of paper stock>
NBKP 20 parts by mass and LBKP 80 parts by mass were 350 ml C.I. S. F. This was beaten into 10 parts by weight of white clay, 0.3 parts by weight of paper strength enhancer (trade name “Polystron 191”, manufactured by Arakawa Chemical Co., Ltd.), sizing agent (trade name “Size Pine E”, Arakawa) Chemical Industry Co., Ltd.) 1.0 part by mass and an appropriate amount of a sulfuric acid band were added to prepare a paper stock.
<Manufacture of paper mesh>
Many resin plates having a short side of 10 mm, a long side of 15 mm, and a thickness of 0.3 mm were prepared. Next, a resin plate was continuously pasted with an adhesive at an interval of 10 mm on a net (on a width of 1300 mm) on a circular net cylinder of a circular net paper machine so that the short side was located in the paper flow direction. Six rows were attached at equal intervals in the width direction of the upper net.
<Paper making>
The upper tank with the resin plate attached was attached to the first tank cylinder of the two-tank paper machine, and the upper net without any work was attached to the second tank circular net cylinder. The second paper layer formed in the second tank overlaps the first paper layer formed in the first tank, and the two layers are combined at the paper making speed of 30 m / min using the above-mentioned paper material. Paper was manufactured. At this time, the thread (width 2.5 mm) created in Example 2 was applied between the first layer (33 g / m ² in terms of dry weight) and the second layer (67 g / m ² ). It was inserted at a position corresponding to the center of the mold using the method proposed in the PR No. 5-4080. Then after dewatering the wet paper by a conventional method, and dried in a cylinder dryer, by producing a window opening thermoresponsive thread containing paper 100 g / m ² comprising two layers Extract alignment paper to give the anti-falsification paper. Although the thread of the obtained anti-counterfeit paper was concerned that the effect of the temperature-responsive coating layer was lost due to heat, rubbing or the like in the paper making process, the effect was not lost and was obtained in Example 2. The same hue change and design characteristics as the thread were confirmed.

Many papers with window thread are processed by using hologram film or aluminum vapor-deposited film as thread, but the hue does not change due to temperature change. However, by engraving the thread of the present invention, it is possible to obtain a sheet with a high anti-counterfeit effect of having a thread whose hue changes with temperature.

Use example 1 when an ultraviolet absorbing layer is provided Example 2 of using UV absorbing layer Use example 3 when an ultraviolet absorbing layer is provided

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Temperature-responsive coating layer 3 Ultraviolet absorption layer

Claims (15)

A thread characterized by having a temperature-responsive coating layer whose hue changes as the temperature changes, on at least one surface of a substrate. The thread according to claim 1, wherein the temperature-responsive coating layer reversibly changes its hue as the temperature changes. The thread according to claim 1 or 2, wherein the substrate is a transparent multilayer film having pearl luster. The thread according to claim 1, wherein the thread has a nacreous layer on the surface of the substrate. The thread according to claim 1, wherein an ultraviolet absorbing layer is provided. The thread according to any one of claims 1 to 5, wherein the temperature at which the hue changes is -4 ° C to 58 ° C. The thread according to any one of claims 1 to 5, wherein the temperature at which the hue changes is from 25C to 33C. The same hue at normal temperature, but two or more types of heat change coating layers having different hues after heat change form an arbitrary pattern on the substrate surface. Thread. Two or more types of temperature-responsive coating layers that exhibit different hues at normal temperature but have the same hue after heat change form a ground pattern on the substrate surface. The thread mentioned. The thread according to claim 1, wherein micro characters are printed on the surface of the base material. The thread according to claim 10, wherein the hue of the micro characters reversibly changes as the temperature changes. The micro character has the same color as that of the temperature-responsive coating layer under a room temperature condition, and changes to a hue different from that of the temperature-responsive coating layer under a temperature condition other than room temperature. Item 12. The thread according to Item 11. The micro character is composed of an ink composed of a pigment component that absorbs infrared rays and a binder, and the spectral reflectance in the infrared region of the micro character and the temperature-responsive coating layer is different under room temperature conditions. The thread according to claim 10, characterized in that A forgery-preventing paper, wherein the thread according to claim 1 is formed on paper. The forgery prevention paper according to claim 14, wherein the thread is intermittently exposed on the paper surface.

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