JP2024017850A - Terminals for determining authenticity of printed matter, software for determining authenticity, systems for determining authenticity - Google Patents

Abstract

The present invention provides a terminal for determining authenticity of printed matter, software for determining authenticity, and a system for determining authenticity. A printed matter has a printed part for visible light reading, a printed part for non-visible light reading, and a redundant printed part. The printed parts form a first identification code 1, a second identification code 2, and a third identification code 3, respectively, and the printed parts for invisible light reading are made of tungsten-based infrared absorbing pigment, ultraviolet absorbing fluorescent It is formed from a non-visible light reading ink containing a pigment, an ultraviolet curable urethane acrylate resin, and an ultraviolet curable acrylic resin that does not contain a urethane bond. The authenticity determination terminal includes a visible light image acquisition unit, an invisible light image acquisition unit that acquires at least one of an infrared image and an ultraviolet fluorescence image, and a visible light image acquisition unit that acquires first to third code information from the first to third identification codes, respectively. It has a processing section that obtains at least two of the codes, and a display section that displays the authenticity determination result based on the code information. [Selection diagram] Figure 1

Description

The present disclosure relates to a terminal for determining the authenticity of printed matter, and particularly to a terminal for determining the authenticity of printed matter for preventing forgery and/or determining authenticity. The present invention also relates to authentication software for an authentication terminal and an authentication system using the authentication terminal.

Various types of printed matter are known for preventing counterfeiting and/or determining authenticity.

For example, Patent Document 1 discloses a forgery prevention printed material having an identification code made up of multiple types of inks each having different spectral reflection characteristics with respect to irradiated light, in which the ink used to print the identification code and the ink mixed in the identification code are used. A forgery prevention printed matter is disclosed, which is characterized by using different types of ink to print the authenticity determination code. Further, here, the plurality of types of ink having different spectral reflection characteristics with respect to irradiation light may be ink that can be seen by irradiation with visible wavelength light and ink that can be seen by irradiation with wavelength light outside the visible range.

According to this document, the following effects can be achieved by such printed materials for preventing counterfeiting:
(1) Since the authenticity determination code is hidden within the identification code and does not require installation space to form both codes separately, the authenticity determination code It is difficult to infer the existence of
(2) Even if you infer the existence of an authenticity determination code and copy the entire identification code, you will not be able to obtain information about the authenticity determination code unless the ink is of a type that responds to the copying light source. do not have. Furthermore, if the ink is of a type that reacts with the copying light source, a message indicating that the product is a copy (=non-genuine product) will be displayed, making the act of forgery obvious.
(3) Divide the entire product into local regions, extract random patterns unintentionally generated during the manufacturing process (or printing process) as "feature points," and then compare slight individual differences with reference data. The verification process is simple because the verification process is not performed by verification, but is intentionally left hidden and the authenticity determination code whose formation location is known in advance (invisible to the naked eye) is verified.
(4) Since the characteristics of the ink forming the identification code and the authenticity determination code are different, when each piece of information is read in the authentication or verification process, there is no noise affecting the other, improving verification accuracy.

Incidentally, infrared absorbing ink is known as a functional ink used to prevent forgery, and for example, invisible printing is applied to a portion of securities to prevent forgery.

Pigments that exhibit an infrared absorbing function and are blended into infrared absorbing inks include cesium tungsten oxide (CWO), antimony-doped tin oxide (ATO), indium tin oxide (ITO), and carbon black. Among these, demand is increasing for infrared absorbing inks that utilize cesium tungsten oxide (CWO) because of their high infrared absorbing ability and high transparency.

For example, Patent Document 2 describes an ink containing a vehicle and fine particles of an infrared absorbing material selected from composite tungsten oxides such as cesium tungsten oxide (CWO) and tungsten oxides having a Magnelli phase.

Further, Patent Document 3 proposes a composition for anti-counterfeiting ink using ultrafine particles of composite tungsten oxide (CWO, etc.) having an XRD peak top intensity ratio within a specific range. It is stated that a fluorescent material may be added to.

However, the tungsten-based infrared absorbing pigments used in the infrared absorbing inks described in Patent Documents 2 and 3 are deactivated by the influence of basic substances such as detergents, and may not be able to maintain their infrared absorbing function. there were.

On the other hand, Patent Document 4 discloses that an ink is prepared by mixing a tungsten-based infrared absorbing pigment, a certain amount of a solvent, an acrylic resin soluble in the solvent, and an ultraviolet curable resin. It has been proposed to impart resistance to basic substances such as detergents (washing resistance) to tungsten-based infrared absorbing pigments.

Japanese Patent Application Publication No. 2019-188756 International Publication No. 2016/121801 International Publication No. 2017/104855 Japanese Patent Application Publication No. 2020-050690

Printed matter printed using infrared absorbing materials such as cesium tungsten oxide (CWO) requires special equipment such as an infrared camera to determine authenticity. For this reason, although the confidentiality is high, the cost of installing equipment is enormous, and if authentication is to be performed at multiple locations, the cost will be high.

Therefore, in determining authenticity, the present disclosers conduct a primary evaluation to prevent counterfeiting using an ultraviolet (UV) irradiation device, which is a generally inexpensive device, before conducting an evaluation of infrared absorption. I recalled.

Specifically, the ink composition contains, in addition to a pigment that exhibits an infrared absorption function, a fluorescent pigment that absorbs ultraviolet (UV) light and emits light. Then, a printed matter is produced using this composition, and this is made into a genuine printed matter.

For printed matter to be determined for authenticity, an evaluation using an ultraviolet (UV) irradiation device is performed as a primary evaluation, and only those that are evaluated as likely to be counterfeit are subjected to a secondary evaluation using an infrared irradiation device. Evaluate infrared absorption using specialized equipment such as a camera.

Furthermore, the two-step evaluation described above can also be applied to printed matter that requires a higher level of security.

However, such an ink composition, that is, an ink composition containing a fluorescent pigment having ultraviolet (UV) absorbing ability in addition to a tungsten-based infrared absorbing pigment, has a tendency to cause washing of the fluorescent pigment due to the interaction of these pigments. There was a tendency for resistance to decrease significantly.

The present disclosure has been made in view of the above background, and exhibits excellent anti-counterfeiting properties and/or authenticity determination properties by having both infrared absorbing properties and ultraviolet absorbing properties, as well as basic resistance, especially washability. The purpose is to provide printed materials with excellent durability.

The present disclosers have conducted extensive studies to solve the above problems. Then, in addition to using a specific visible light reading printing part and non-visible light reading printing part, an ink composition using an ultraviolet curable urethane acrylate resin together with a tungsten-based infrared absorbing pigment and an ultraviolet absorbing fluorescent pigment is used. We have discovered that the above problems can be solved, and have completed the present disclosure. That is, the present disclosure is as follows.

<Aspect 1>
A terminal for determining the authenticity of a printed matter, and a device configured to be able to communicate with the terminal for determining authenticity, receiving the code information from the terminal for determining authenticity, determining the authenticity based on the received code information, and determining the result of the authenticity determination. a server that transmits the information to the authentication terminal;
An authentication system comprising:
The printed matter is
It has a printed part for visible light reading printed with ink for reading visible light, and a printed part for invisible light reading printed with ink for reading invisible light,
The visible light reading printing section and the non-visible light reading printing section at least partially overlap to form an overlapping printing section,
A first identification code formed by the visible light reading print section, a second identification code formed by the non-visible light reading print section, and a third identification code formed by the overlapping print section. at least two of the identification codes;
The invisible light reading ink is
Tungsten-based infrared absorbing pigment,
UV-absorbing fluorescent pigments,
UV-curable urethane acrylate resin, UV-curable acrylic resin that does not contain urethane bonds,
including;
The authenticity determination terminal is
a visible light image acquisition unit that acquires a visible light image of the visible light reading printing unit;
a non-visible light image acquisition unit that obtains a non-visible light image of the non-visible light reading printing unit;
a first processing unit that recognizes a first identification code from the visible light image to obtain first code information; a first processing unit that recognizes a second identification code from the non-visible light image to obtain second code information; at least two of the third processing unit that recognizes the third identification code from the visible light image and the non-visible light image to obtain third code information; It has a display section that displays the authenticity determination result based on the
The invisible light image acquisition unit obtains at least one of an infrared image and an ultraviolet fluorescence image as the invisible light image.
Authenticity determination system.
<Aspect 2>
The system according to claim 1, wherein the server further records information regarding the authenticity determination in a database in association with the received code information.
<Aspect 3>
2 or more of the authentication terminals,
A first authentication terminal of the authentication terminals obtains only at least one of an infrared image and an ultraviolet fluorescence image as the non-visible light image.
A second authentication terminal among the authentication terminals selects both the infrared image and the ultraviolet fluorescence image, or the first authentication of the infrared image and the ultraviolet fluorescence image as the non-visible light image. Obtain the one that is not obtained on the judgment terminal,
The system according to aspect 1 or 2.
<Aspect 4>
The printed matter has at least the third identification code, and the authentication terminal has at least the third processing section.
The system according to any one of aspects 1 to 3.
<Aspect 5>
The system according to any one of aspects 1 to 4, wherein the visible light reading ink is a non-infrared absorbing ink.
<Aspect 6>
The system according to any one of aspects 1 to 5, wherein the ultraviolet curable urethane acrylate resin is contained in an amount of 1 to 150 parts by mass based on 100 parts by mass of the ultraviolet curable acrylic resin.
<Aspect 7>
The system according to any one of aspects 1 to 6, wherein the tungsten-based infrared absorbing pigment is contained in an amount of 20 parts by mass or less based on 100 parts by mass of the total solid content in the invisible light reading ink.
<Aspect 8>
The system according to any one of aspects 1 to 7, wherein the ultraviolet absorbing fluorescent pigment is contained in an amount of 20 parts by mass or less based on 100 parts by mass of total solid content in the invisible light reading ink.
<Aspect 9>
The system according to any one of aspects 1 to 8, wherein the ultraviolet curable urethane acrylate resin is contained in 1 to 50 parts by mass based on 100 parts by mass of total solid content in the invisible light reading ink.
<Aspect 10>
The system according to any one of aspects 1 to 9, wherein the ultraviolet curable urethane acrylate resin contains a plurality of acryloyl groups.
<Aspect 11>
The tungsten-based infrared absorbing pigment is
General formula (1): M _x W _y O _z
{In the formula, M is H, He, alkali metal element, alkaline earth metal element, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, One or more elements selected from the group consisting of Re, Be, Hf, Os, Bi, and I, W is tungsten, O is oxygen, and x, y, and z are each positive numbers. , 0<x/y≦1 and 2.2≦z/y≦3.0}
Composite tungsten oxide represented by, or
General formula (2): W _y O _z
{In the formula, W is tungsten, O is oxygen, y and z are each positive numbers, and 2.45≦z/y≦2.999}
Tungsten oxide having a Magnelli phase represented by
The system according to any one of aspects 1 to 10, wherein the system is at least one selected from the following.
<Aspect 12>
The system according to any one of aspects 1 to 11, wherein the invisible light reading printing section is inkjet printed.
<Aspect 13>
The authentication terminal according to any one of aspects 1 to 9.
<Aspect 14>
Authenticity determination software for the authenticity determination terminal according to aspect 13,
causing the visible light image acquisition unit to acquire a visible light image of the visible light reading printing unit;
causing the invisible light image acquisition section to acquire a non-visible light image of the invisible light reading printing section, and causing the first processing section to recognize a first identification code from the visible light image to generate a first identification code. acquiring code information, causing the second processing unit to recognize a second identification code from the non-visible light image and acquiring second code information, and causing the third processing unit to recognize the second identification code from the invisible light image; performing at least two of the following: recognizing a third identification code from an image and the non-visible light image to obtain third code information;
Authenticity determination software.

The printed matter of the present disclosure exhibits excellent anti-counterfeiting properties and/or authenticity determination properties by having both infrared absorbing properties and ultraviolet absorbing properties, and has excellent base resistance, particularly washing resistance. Therefore, even if the printed matter of the present disclosure is washed together with clothing, it can maintain its infrared absorption function and ultraviolet absorption function due to its base resistance, and therefore has excellent anti-counterfeiting properties and/or authenticity determination. can maintain sex.

Further, the printed matter of the present disclosure has both infrared absorbency and ultraviolet absorbency. Therefore, when determining the authenticity of printed matter of unknown authenticity, an ultraviolet (UV) irradiation device, which is generally an inexpensive device, is used for primary evaluation (e.g., confirmation of code information based on the identification code and/or visual inspection). Only in cases where there is a risk of counterfeit products or where security is required, an evaluation of infrared absorption using specialized equipment such as an infrared camera is performed as a secondary evaluation. be able to.

In other words, if the printed matter of the present disclosure is considered to be a genuine printed matter, the authenticity determination for printed matter of unknown authenticity is a two-stage evaluation consisting of a primary evaluation and a secondary evaluation, and the primary evaluation is a simple ultraviolet (UV) absorption evaluation. Accordingly, it is possible to limit the objects on which secondary evaluation is performed. Therefore, according to the present disclosure, the convenience of determining authenticity can be improved, the cost of introducing an expensive infrared evaluation device can be suppressed, and the situations in which authentication can be used can be expanded.

FIG. 1 is a conceptual diagram showing one aspect of the printed matter of the present disclosure. FIG. 2 is a conceptual diagram showing another aspect of the printed matter of the present disclosure. FIG. 3 is a schematic configuration diagram showing the configuration of the authentication terminal of the present disclosure. FIG. 4 is a flowchart showing one aspect of control of the authentication terminal of the present disclosure. FIG. 5 is a flowchart showing another aspect of control of the authentication terminal according to the present disclosure. FIG. 6 is a schematic configuration diagram showing the configuration of the authenticity determination server used in the authenticity determination system of the present disclosure. FIG. 7 is a sequence diagram for explaining one aspect of the authenticity determination system of the present disclosure. FIG. 8 is a sequence diagram for explaining another aspect of the authenticity determination system of the present disclosure.

Hereinafter, specific aspects of the printed matter, authentication terminal, authenticity determination software, and authenticity determination system of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to these aspects. do not have.

《Printed materials》
The printed matter of this disclosure is
It has a printed part for visible light reading printed with ink for reading visible light, and a printed part for invisible light reading printed with ink for reading invisible light,
The visible light reading printing section and the non-visible light reading printing section at least partially overlap to form an overlapping printing section.

Further, the printed matter of the present disclosure includes a first identification code formed by the visible light reading printing section (that is, included in the visible light reading printing section), and a first identification code formed by the invisible light reading printing section. and a third identification code formed by the overlapping printing portion. In particular, the printed matter of the present disclosure has at least a third identification code.

Here, the invisible light reading ink is
Tungsten-based infrared absorbing pigment,
UV-absorbing fluorescent pigments,
UV-curable urethane acrylate resin, UV-curable acrylic resin that does not contain urethane bonds,
Contains.

In addition, visible light reading ink is a non-infrared absorbing ink, that is, it does not absorb or substantially absorbs infrared light, and when printed on an identification code printed with infrared absorbing ink, it has an infrared absorbing ink. The ink may be any ink that does not interfere with the reading of the identification code printed with the ink. Therefore, the ink for visible light reading may specifically be an ink that does not contain carbon black pigment.

In the context of this disclosure, an "identification code" may be a one-dimensional code or a two-dimensional code. Specific examples of one-dimensional codes include barcodes such as CODE39, CODE128, JAN, and ITF, and specific examples of two-dimensional codes include QR code, PDF417, Data Matrix, CP code, MaxiCode, etc. can be mentioned. Further, in relation to the present disclosure, the "identification code" is not limited to these general identification codes, and a pattern or a portion thereof may function as a one-dimensional code or a two-dimensional code. Note that the identification code applicable to the present disclosure includes a blank space and a code portion, but when forming the identification code on a base material by printing, printing, etc., only the code portion may be formed. In other words, in this case, the base material itself becomes the blank space.

Furthermore, in the present disclosure, "code information" means information possessed by an identification code, and particularly means information obtained by decoding the identification code.

The base material for the printed matter of the present disclosure is not particularly limited, and includes, for example, a paper base material, a plastic base material, a metal base material, a fiber base material, a glass base material, a rubber base material, and a leather base material. good.

When the base material is a paper base material, the printed matter of the present disclosure may be a banknote, a security, a card, a label, a wrapping paper, a packaging bag, a paper box (particularly a paper box for pharmaceutical products or cosmetics), cardboard, etc.

When the base material is a plastic base material, the printed matter of the present disclosure can be used for banknotes, securities, cards, labels, packaging films (including sheets such as PTP (press-through packaging)), packaging bags, and various molded products ( Specifically, packaging containers such as bottles, tubes, and jars, electrical appliances, automobile parts, coins, medals, casino chips, etc.) may be used.

When the base material is a metal base material, the printed matter of the present disclosure may be an electrical appliance, a metal part (particularly an industrial part for an automobile, an electronic part), a coin, a medal, a casino chip, or the like.

When the base material is a fiber base material, the printed matter of the present disclosure may be a filter of clothing, shoes, a bag, a wallet, a nonwoven fabric, etc., or a label attached to the filter (especially a care label, a brand label), etc.

When the base material is a glass base material, the printed matter of the present disclosure may be a bottle, a glass substrate, a window material (for architecture, automobiles, etc.), or the like.

When the base material is a rubber base material, the printed matter of the present disclosure may be a tire, a hose, a vibration isolator, a seal ring, a gasket, a packing, etc.

When the base material is a leather base material, the printed matter of the present disclosure may be clothing, shoes, bags, wallets, etc.

In one aspect of the printed matter of the present disclosure illustrated in FIG.
a first identification code 1 formed by a visible light reading printing section printed with visible light reading ink;
A second identification code 2 formed by a printed part for invisible light reading printed with invisible light reading ink, and an overlapping part that is an overlapping part of the printed part for visible light reading and the printed part for invisible light reading. a third identification code 3 formed by the printing unit;
It is shown.

The visible light reading ink used in this printed material is readable with visible light, so images can be captured with a normal camera and visually recognized.

As such visible light reading ink, normal process inks, that is, cyan (C), magenta (M), yellow (Y), and black (K) inks can be used. Also, the visible light reading ink may be a non-infrared absorbing ink and therefore may not contain carbon black pigment. The black non-infrared absorbing visible light reading ink can be obtained as a mixed color black ink containing cyan (C), magenta (M), and yellow (Y). If the visible light reading ink is a non-infrared absorbing ink, when acquiring an infrared image, only the part printed with the non-visible light reading ink is read without reading the part printed with the visible light reading ink. can be read.

In addition, the invisible light reading ink used in this printed material is impossible or substantially difficult to read with visible light, so it is difficult to capture images with a normal camera or with the naked eye. Impossible or substantially difficult to see. On the other hand, this non-visible light reading ink contains a tungsten-based infrared absorbing pigment and can therefore be read using an infrared camera. In addition, this invisible light reading ink contains ultraviolet-absorbing fluorescent pigments, and the fluorescence generated by irradiation with ultraviolet light can be read using an ordinary camera or visually confirmed. be able to. Details of the ink for invisible light reading will be described in detail in the section "<<Ink for reading invisible light>>" below.

(Aspect shown in Figure 1)
In the embodiment shown in FIG. 1, as shown in FIG. 1(a), a first identification code 1 that can be read with visible light and a second identification code 2 that can be read with invisible light are attached to a base material such as paper. printed.

Therefore, when a visible light image (Fig. 1 (b1)) and an ultraviolet fluorescence image (Fig. 1 (c1)) of a substrate having this identification code are acquired, the first identification code is obtained from the visible light image (Fig. 1 (b1)). Code 1 can be obtained, and a second identification code 2 can also be obtained from the ultraviolet fluorescence image (FIG. 1(c1)). Furthermore, by referring to these images in combination, it is possible to obtain the third identification code 3 formed by the overlapping portion of these identification codes.

Similarly, when a visible light image (Fig. 1 (b2)) and an infrared image (Fig. 1 (c2)) of the base material having this identification code are acquired, the first identification code is obtained from the visible light image (Fig. 1 (b2)). Code 1 can be obtained, and second identification code 2 can also be obtained from the infrared image (FIG. 1(c2)). Furthermore, by referring to these images in combination, it is possible to obtain the third identification code 3 formed by the overlapping portion of these identification codes.

That is, for example, in the embodiment shown in FIG. 1, the first to third identification codes obtained by acquiring a visible light image (FIG. 1 (b1)) and an ultraviolet fluorescence image (FIG. 1 (c1)) of the base material Based on this, a primary evaluation is made as to whether or not this printed material is a genuine printed material, and a visible light image (Fig. 1 (b2)) and an ultraviolet image (Fig. 1 (c2)) of the base material are obtained. Based on the obtained first to third identification codes, it is possible to perform a secondary evaluation as to whether or not this printed matter is a genuine printed matter.

Therefore, as a primary evaluation of printed matter that is subject to authenticity determination, an evaluation using an ultraviolet (UV) irradiation device is conducted, and only for those that are evaluated to be likely to be counterfeit, a secondary evaluation is performed. , infrared absorption can be evaluated using dedicated equipment such as an infrared camera. Note that in the primary evaluation, only the presence or absence of fluorescence can be visually confirmed without acquiring the second identification code 2 from the ultraviolet fluorescence image (FIG. 1 (c1)).

(Aspect shown in Figure 2)
In the embodiment shown in FIG. 2, as shown in FIG. 2(a), a pattern (not an identification code) 1' that can be read with visible light and a second identification code 2 that can be read with invisible light are attached to a paper or the like. printed on the base material.

Therefore, when a visible light image (Fig. 2 (b1)) and an ultraviolet fluorescence image (Fig. 2 (c1)) of a substrate having this identification code are obtained, a second identification code is obtained from the ultraviolet fluorescence image (Fig. 2 (c1)). Code 2 can be obtained. Furthermore, by referring to these images in combination, it is possible to obtain a third identification code 3' formed by the overlapping portion of these identification codes. The identification code 3' shown in FIG. 2 functions as an identification code by specifying a specific position of the pattern.

Similarly, when a visible light image (FIG. 2 (b2)) and an infrared image (FIG. 2 (c2)) of the substrate having this identification code are acquired, a second identification code is obtained from the infrared image (FIG. 2 (c2)). 2 can be obtained. Furthermore, by referring to these images in combination, it is possible to obtain a third identification code 3' formed by the overlapping portion of these identification codes.

That is, for example, in the embodiment shown in FIG. 2, the second and third identification codes obtained by acquiring a visible light image (FIG. 2 (b1)) and an ultraviolet fluorescence image (FIG. 2 (c1)) of the base material Based on this, a primary evaluation is made as to whether or not this printed material is a genuine printed material, and a visible light image (Fig. 2 (b2)) and an ultraviolet image (Fig. 2 (c2)) of the base material are obtained. Based on the obtained second and third identification codes, it is possible to perform a secondary evaluation as to whether or not this printed matter is a genuine printed matter.

Therefore, similarly to the embodiment shown in Fig. 1, printed matter to be determined for authenticity is subjected to a primary evaluation using an ultraviolet (UV) irradiation device, and those that are evaluated to be likely to be counterfeit. As a secondary evaluation, evaluation of infrared absorption using a dedicated device such as an infrared camera can be carried out only for the above cases. In addition, in the primary evaluation, only the presence or absence of fluorescence can be visually confirmed without acquiring the second identification code 2 from the ultraviolet fluorescence image (FIG. 2(c1)).

《Authenticity determination terminal》
The authenticity determination terminal of the present disclosure is a terminal for determining the authenticity of printed matter of the present disclosure.

The authentication terminal according to the present disclosure includes:
a visible light image acquisition unit that acquires a visible light image of the visible light reading printing unit;
an invisible light image acquisition unit that acquires an invisible light image of the printing unit for invisible light reading;
a first processing unit that recognizes a first identification code from a visible light image and obtains first code information; a second processing unit that recognizes a second identification code from a non-visible light image and obtains second code information; at least two of the second processing unit and the third processing unit that recognizes the third identification code from the visible light image and the non-visible light image to obtain the third code information; and the authentication based on the code information. It has a display section that displays a determination result, and a non-visible light image acquisition section obtains at least one of an infrared image and an ultraviolet fluorescence image as a non-visible light image.

In the authenticity determination terminal of the present disclosure, preferably, the printed matter has at least the third identification code, and the authenticity determination terminal preferably has at least the third processing section. Further, in the authentication terminal of the present disclosure, preferably the visible light reading ink is a non-infrared absorbing ink.

The authentication terminal of the present disclosure may be a smartphone, a tablet, a handy terminal, a personal computer, a POS (point of sales) cash register, or the like.

FIG. 3 is a diagram schematically showing the configuration of the authentication terminal 100 of the present disclosure.

As shown in FIG. 3, the authentication terminal 100 of the present disclosure includes an external communication interface (external communication I/F) 110, an image acquisition section 120, a storage 130, a display section 140, a processor 190a, and a memory 190b.

The image acquisition unit 120 of the authentication terminal 100 includes a visible light image acquisition unit that acquires a visible light image of a visible light reading printing unit, and an invisible light image acquisition unit that acquires a nonvisible light image of a nonvisible light reading printing unit. It functions as an image acquisition section.

Specifically, in order for the image acquisition unit 120 to function as a visible light image acquisition unit that acquires visible light images, the image acquisition unit 120 can have a function as a normal camera. The non-visible light image acquisition unit obtains at least one of an infrared image and an ultraviolet fluorescence image as a non-visible light image. Therefore, in order for the image acquisition unit 120 to function as a non-visible light image acquisition unit that acquires a non-visible light image, the image acquisition unit 120 may be an infrared camera, and/or may be an infrared camera that uses ultraviolet rays as an object to be photographed. It may be an ordinary camera that photographs the fluorescence generated by irradiation. Note that even if the image acquisition unit 120 is a single image acquisition unit that can capture two or all of visible light images, infrared images, and ultraviolet fluorescence images, it may capture only one of them. It may be a combination of two or more image acquisition units that can take images.

The visible light image acquisition section and non-visible light image acquisition section may be an external image acquisition section or a built-in image acquisition section. When the image acquisition unit is externally attached, connection to other parts of the authentication terminal 100 can be made by wire or wirelessly. In the case of wired connection, a USB cable, lighting cable, etc. can be used for connection. Furthermore, in the case of wireless connection, Bluetooth (registered trademark), Wi-Fi, etc. can be used for connection.

The processor 190a of the authentication terminal 100, together with the memory 190b as necessary, includes a first processing unit that recognizes the first identification code from the visible light image and acquires the first code information, and a first processing unit that recognizes the first identification code from the visible light image and acquires the first code information from the invisible light image. a second processing unit that recognizes the second identification code and acquires the second code information; and a second processing unit that recognizes the third identification code from the visible light image and the non-visible light image and acquires the third code information. It functions as a third processing section. Note that even if the processor 190a is a single processor that functions as two or all of the processing units of the first to third processing units, it may be a single processor that functions as only one of them. A combination of the above may also be used.

Specifically, the processor 190a includes one or more CPUs (Central Processing Units) and their peripheral circuits, and executes various processes. Note that the processor 190a may further include an arithmetic circuit such as a logical arithmetic unit or a numerical arithmetic unit. Details of processing by the processor are discussed below with respect to FIGS. 4 and 5.

Further, the memory 190b may be, for example, a volatile semiconductor memory (eg, RAM) or a nonvolatile semiconductor memory (eg, ROM). The memory 190b stores programs executed by the processor 190a, various data used when the processor 190a executes various processes, and the like.

The external communication interface 110 of the authentication terminal 100 allows communication between the authentication terminal 100 and the server via a wireless communication antenna mounted on the authentication terminal or a cable connected to the authentication terminal. It may be a device that makes it possible. External communication interface 110 includes, for example, a data communication module (DCM). The data communication module may communicate with the server via the Internet.

The storage device 130 of the authentication terminal 100 includes, for example, a hard disk drive (HDD), a solid state drive (SSD), or an optical recording medium. The storage device 130 stores various data, such as computer programs for the processor 190a to execute various processes. A computer program may be distributed by being recorded on a recording medium such as an optical recording medium or a magnetic recording medium, or may be distributed via the Internet.

The authenticity determination terminal 100 can include a human machine interface (HMI). The HMI is an input/output device that inputs and outputs information between the authentication terminal 100 and its user. The HMI includes, for example, a display that displays information, a speaker that generates sound, an operation button or touch screen that allows the user to perform input operations, a microphone that receives the user's voice, and the like. In particular, the HMI may be a display unit 120, such as a liquid crystal display, an organic EL display, or the like.

Authenticity determination by the authentication terminal of the present disclosure can be performed as shown in the flowcharts of FIGS. 4 and 5.

Specifically, in the embodiment shown in the flowchart of FIG. 4, the determination is started (S10), the visible light image acquisition section acquires a visible light image of the visible light reading printing section (S21), and the non-visible light image is acquired. A first processing section obtains an invisible light image of the printing section for invisible light reading (S22), a first processing section obtains first code information from the visible light image, and a second processing section obtains an invisible light image of the printing section for invisible light reading. Two of the following are performed: acquiring second code information from the optical image, and acquiring third code information from the visible light image and non-visible light image in the third processing unit (S32).

After that, the authenticity is determined using one of the two acquired code information (S41), and if the code information is determined to be genuine, a provisional determination is made that the printed matter is genuine, and the next Proceed to step (S42). In addition, if the code information is not shown to be genuine in this authenticity determination step (S41), or if a significant identification code was not obtained in the previous step (S32), the printed matter is deemed to be inauthentic. It is determined that there is one (S52), and the process ends (S60).

If it is tentatively determined that the printed material is genuine in the previous authentication step (S41), the authenticity is determined using the other one of the two acquired code information (S42), and it is determined that the code information is genuine. If it is determined that the printed matter is genuine, it is determined that the printed matter is genuine, and the process ends (S60). In addition, if the code information is not shown to be genuine in this authenticity determination step (S42), or if a significant identification code was not obtained in the previous step (S32), the printed matter is deemed to be inauthentic. It is determined that there is one (S52), and the process ends (S60).

That is, in the embodiment shown in the flowchart of FIG. 4, it is possible to determine whether a printed matter is genuine or not in two stages. Further, this aspect can be implemented using at least one of an infrared image and an ultraviolet fluorescence image as the non-visible light image.

In the embodiment shown in the flowchart of FIG. 4, two of the first to third identification codes are acquired and the authenticity determination is performed based on them, whereas in the embodiment shown in the flowchart of FIG. All of the first to third identification codes are obtained, and the authenticity is determined based on them.

Specifically, in the embodiment shown in the flowchart of FIG. 5, the determination is started (S10), the visible light image acquisition unit acquires a visible light image of the visible light reading printing unit (S21), and the non-visible light image is acquired. A first processing section obtains an invisible light image of the printing section for invisible light reading (S22), a first processing section obtains first code information from the visible light image, and a second processing section obtains an invisible light image of the printing section for invisible light reading. All of the steps of acquiring the second code information from the optical image and acquiring the third code information from the visible light image and the non-visible light image in the third processing unit are performed (S33).

After that, the authenticity is determined using one of the three acquired code information (S41), and if the code information is determined to be genuine, a provisional determination is made that the printed matter is genuine, and the next Proceed to step (S42). In addition, if the code information is not shown to be genuine in this authenticity determination step (S41), or if a significant identification code was not obtained in the previous step (S33), the printed matter is deemed to be inauthentic. It is determined that there is one (S52), and the process ends (S60).

If it is tentatively determined that the printed material is genuine in the previous authentication step (S41), the authenticity is determined using another one of the three acquired code information (S42), and it is determined that the code information is genuine. If it is determined that the printed matter is genuine, a provisional determination is made that the printed matter is genuine, and the process proceeds to the next step (S43). In addition, if the code information is not shown to be genuine in this authenticity determination step (S42), or if a significant identification code was not obtained in the previous step (S33), the printed matter is deemed to be inauthentic. It is determined that there is one (S52), and the process ends (S60).

If it is tentatively determined that the printed material is genuine in the previous authenticity determination step (S42), the authenticity is determined using the remaining one of the three acquired code information (S43), and it is determined that the code information is genuine. If it is determined that the printed matter is genuine, it is determined that the printed matter is genuine (S51), and the process ends (S60). In addition, if the code information is not shown to be genuine in this authenticity determination step (S43), or if a significant identification code was not obtained in the previous step (S33), the printed matter is deemed to be inauthentic. It is determined that there is one (S52), and the process ends (S60).

That is, in the embodiment shown in the flowchart of FIG. 5, it is possible to determine whether a printed matter is genuine or not in three stages. Further, this aspect can be implemented using at least one of an infrared image and an ultraviolet fluorescence image as the non-visible light image.

Furthermore, if the terminal has a database regarding authentic code information in its storage, the determination of whether the printed matter is genuine can be made based on that database, and if the terminal has an external communication interface, it can be determined based on the database. This can be done by accessing a server containing a database of authentic code information via an external communication interface. Further, it is also possible to determine whether the printed matter is genuine or not by determining whether the code information conforms to predetermined rules.

《Authenticity determination software》
Authenticity determination software of the present disclosure is authenticity determination software for the authenticity determination terminal of the present disclosure,
causing the visible light image acquisition unit to acquire a visible light image of the visible light reading printing unit;
The invisible light image acquisition section acquires the invisible light image of the invisible light reading printing section, and the first processing section recognizes the first identification code from the visible light image to acquire the first code information. the second processing unit recognizes the second identification code from the invisible light image and obtains the second code information; and the third processing unit recognizes the second identification code from the visible light image and the invisible light image. At least two of the steps of recognizing the third identification code and acquiring third code information are performed.

For details of the authenticity determination software of the present disclosure, the description regarding the authenticity determination terminal of the present disclosure can be referred to.

《Authenticity determination system》
The authenticity determination system of the present disclosure includes:
It is provided to be able to communicate with the authenticity determination terminal and the authenticity determination device of the present disclosure, receives code information from the authenticity determination terminal, performs authenticity determination based on the received code information, and uses the result of the authenticity determination for authenticity determination. server to send to the terminal,
It is equipped with

In the authenticity determination system of the present disclosure, preferably, the server further records information regarding authenticity determination in the database in association with the received code information. Here, the "information regarding authenticity determination" may include distribution process information, such as the date and time of authenticity determination, the number of times, and the ID of the terminal.

According to this, traceability of the printed matter of the present disclosure and/or products distributed together with the printed matter of the present disclosure can be improved. In particular, by having a terminal read the code at each stage of distribution, it can be used for distribution management. For example, it is possible to prevent the inflow of counterfeit products and record the distribution history by reading the information at the time of receipt and shipment at a distribution base and at the time of sale at a store. In addition, when illegal distribution such as diversion occurs, by obtaining the illegally distributed goods and reading the code, it is possible to trace at what stage the product deviated from the official route.

In the past, illegally distributed products were tampered with, such as by removing the lot number or serial number, so that their origin could not be determined. On the other hand, if the printed matter of the present disclosure is used, the code cannot be visually confirmed, so the risk of tampering can be significantly reduced. Even if it were discovered, it would be difficult to counterfeit because the materials used are very limited. If materials other than tungsten-based infrared-absorbing pigments are used (e.g., antimony-doped tin oxide (ATO)-based infrared-absorbing pigments, which have relatively low infrared absorption and transparency, tin-doped indium oxide (ITO)-based infrared-absorbing pigments, etc.) When an invisible code is created using an ink using the same method, there is a problem that it becomes visible to the naked eye.

The authentication system of the present disclosure preferably includes two or more authentication terminals,
A first authentication terminal among the authentication terminals acquires at least one of an infrared image and an ultraviolet fluorescence image, particularly only an ultraviolet fluorescence image, as a non-visible light image;
The second authentication terminal among the authentication terminals uses both an infrared image and an ultraviolet fluorescent image as a non-visible light image, or the first authentication terminal uses an infrared image and an ultraviolet fluorescent image as a non-visible light image. Get what you don't have.

According to this, by using the first authentication terminal as a primary authentication device and the second authentication terminal as a secondary authentication device, the authentication can be performed in two stages. It can be done carefully. In addition, since ultraviolet fluorescence images can be obtained relatively easily using an ultraviolet light, the first authenticity determination terminal is usually configured as a terminal that acquires only ultraviolet fluorescence images. Authenticity can be determined using a second authentication terminal, and when a more careful authentication becomes necessary, a second authentication terminal capable of acquiring an infrared image can be used to perform the authentication.

FIG. 6 is a diagram schematically showing the configuration of a server 200 used in the authentication terminal system of the present disclosure.

As shown in FIG. 6, the authenticity determination server 200 of the present disclosure includes an external communication interface (external communication I/F) 210, a storage 230, a processor 290a, and a memory 290b.

The processor 290a of the authenticity determination server 200, together with the memory 290b as necessary, performs the authenticity determination based on the code information received from the authenticity determination device, and transmits the result of the authenticity determination to the authenticity determination terminal.

For details of the external communication interface (external communication I/F) 210, storage 230, processor 290a, and memory 290b used in the authenticity determination server 200, the description regarding the authenticity determination terminal can be referred to.

Authenticity determination by the authenticity determination system of the present disclosure can be performed as shown in the sequence diagram of FIG.

That is, in the embodiment whose sequence diagram is shown in FIG. 7, the authentication terminal 100 of the present disclosure acquires code information from a visible light image and an infrared image, or from a visible light image and an ultraviolet fluorescence image (S110), Then, the acquired code information is transmitted to the authenticity determination server 200 (S120). Thereafter, the authenticity determination server 200 that has received the code information from the authenticity determination terminal 100 performs an authenticity determination based on this code information (S210), registers the determination result in the database as necessary (S220), and The determination result is transmitted to the authentication terminal 100 (S230). The authenticity determination terminal 100 that has received the determination result from the authenticity determination server 200 can display the determination result on the display device (S130).

A first authentication terminal among the authentication terminals acquires only an ultraviolet fluorescence image as a non-visible light image, and a second authentication terminal among the authentication terminals acquires an ultraviolet fluorescence image as a non-visible light image. When both an infrared image and an ultraviolet fluorescence image or an infrared image are acquired as images, the authenticity determination by the authentication system of the present disclosure can be performed as shown in the sequence diagram of FIG. 8 .

That is, in the embodiment whose sequence diagram is shown in FIG. 8, first, the first authentication terminal 101 acquires code information from an ultraviolet fluorescence image as a non-visible light image (S111), and then uses the acquired code information. is transmitted to the authenticity determination server 200 (S121). Thereafter, the authentication server 200 that has received the code information from the first authentication terminal 101 performs authentication based on this code information (S211), and registers the determination result in the database as necessary (S221). ), and transmits the determination result to the authentication terminal 101 (S231). The first authentication terminal 101 that has received the determination result from the authenticity determination server 200 can display the determination result on the display device (S131).

In addition, in the embodiment shown in the sequence diagram in FIG. 8, the second authentication terminal 102 obtains code information from both an infrared image and an ultraviolet fluorescence image as a non-visible light image, or an infrared image as a non-visible light image. (S112), and transmits the acquired code information to the authenticity determination server 200 (S122). Thereafter, the authenticity determination server 200 that has received the code information from the second authentication terminal 102 performs authentication based on this code information (S212), and registers the determination result in the database as necessary (S222). ), and transmits the determination result to the authentication terminal 102 (S232). The second authentication terminal 102 that has received the determination result from the authenticity determination server 200 can display the determination result on the display device (S132).

《Ink for invisible light reading》
The invisible light reading ink contains a tungsten-based infrared absorbing pigment, an ultraviolet absorbing fluorescent pigment, an ultraviolet curable urethane acrylate resin, and an ultraviolet curable acrylic resin containing no urethane bond.

Here, in the present disclosure, "ultraviolet curable resin" means a material that is cured by polymerization, crosslinking, etc. using the energy of ultraviolet rays irradiated from an ultraviolet irradiation device and a photopolymerization initiator, and is a material that is cured by polymerization, crosslinking, etc. It may be in the form of a prepolymer.

The non-visible light reading ink contains a tungsten-based infrared absorbing pigment, thereby making it possible to provide printed matter with infrared absorbing performance. Further, by including an ultraviolet absorbing fluorescent pigment, a printed matter having ultraviolet absorbing performance can be provided. Furthermore, by including an ultraviolet curable urethane acrylate resin, it is possible to realize a printed matter that has ultraviolet curable performance and has excellent base resistance, particularly washing resistance.

Even when trying to disperse tungsten-based infrared-absorbing pigments that provide infrared-absorbing performance in conventional inks whose main component is ultraviolet-curable acrylic resins that do not contain urethane bonds, the pigments tend to settle in the ink. Alternatively, the pigment-containing dispersion may separate from the ultraviolet curable ink, making it difficult to use it as a printing ink.

In addition, when a UV-absorbing fluorescent pigment that imparts UV-absorbing properties is included in a conventional ink whose main component is an UV-curable acrylic resin that does not contain urethane bonds, it has poor base resistance, especially when washed. Printed matter with excellent durability can be realized. However, when an ink is dispersed together with a tungsten-based infrared absorbing pigment, its washing resistance is greatly impaired.

Furthermore, the ultraviolet curable urethane acrylate resin that imparts washing resistance has a high viscosity. Therefore, a composition containing an ultraviolet curable urethane acrylate resin as a component could not be used as an inkjet ink as it is.

On the other hand, the present disclosers have found that by using an ultraviolet curable acrylic resin that has low viscosity and high compatibility with the ultraviolet curable urethane acrylate resin, the tungsten-based infrared absorbing pigment can be dispersed well, and The function of the UV-absorbing fluorescent pigment can be maintained even in the presence of the tungsten-based infrared-absorbing pigment, and furthermore, the increase in ink viscosity caused by the UV-curable urethane acrylate resin can be suppressed. As a result, they discovered that it was possible to create a practical ink.

Although not bound by theory, it is believed that the above effects are produced by the following mechanism.

Since this ink contains an ultraviolet curable urethane acrylate resin, hydrogen bonds can be formed by urethane bonds. Therefore, the tungsten-based infrared absorbing pigment and the ultraviolet absorbing fluorescent pigment form hydrogen bonds with the ultraviolet curable urethane acrylate resin to form a coating. When these pigments are coated with a resin, their dispersibility in ink is improved, and when printed matter is made, the base resistance, particularly the washing resistance, is improved. Moreover, the resin coating reduces the interaction between the tungsten-based infrared absorbing pigment and the ultraviolet absorbing fluorescent pigment, thereby maintaining the function of the ultraviolet absorbing fluorescent pigment. Furthermore, since this ink contains a UV-curable acrylic resin that is highly compatible with UV-curable urethane acrylate resins, the formation of hydrogen bonds between the UV-curable urethane acrylate resins is inhibited, resulting in a decrease in the viscosity of the ink. It is thought that the increase will be suppressed.

The viscosity of the invisible light reading ink may be 300 mPa·s or less, 150 mPa·s or less, 80 mPa·s or less, or 60 mPa·s or less, and 10 mPa·s or more, or 15 mPa·s or less at a temperature of about 25°C. It may be greater than or equal to s.

Note that when the invisible light reading ink is used as an inkjet ink, the viscosity of the ink is preferably 60 mPa·s or less, may be 40 mPa·s or less, 30 mPa·s or less, and may be 20 mPa·s or less. s or less is particularly preferable.

<Tungsten-based infrared absorbing pigment>
The invisible light reading ink contains a tungsten-based infrared absorbing pigment dispersed therein as an essential component. The non-visible light reading ink contains a tungsten-based infrared absorbing pigment, thereby making it possible to provide printed matter with infrared absorbing performance.

The tungsten-based infrared absorbing pigment used in the present disclosure is not particularly limited, and known pigments used in the field of inks can be used.

Examples of tungsten-based infrared absorbing pigments include general formula (1): M _x W _y O _z {where M is H, He, an alkali metal element, an alkaline earth metal element, a rare earth element, Mg, Zr , Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B , F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I, and W is tungsten, O is oxygen, x, y and z are each positive numbers, 0<x/y≦1, and 2.2≦z/y≦3.0}. Composite tungsten oxide represented by the general formula (2): W _y O _z {where W is tungsten, O is oxygen, y and z are each positive numbers, and 2.45 ≦z/y≦2.999} The infrared absorbing pigment may be one or more types of infrared absorbing pigments selected from tungsten oxides having a Magneli phase.

Such a tungsten-based infrared absorbing pigment can be produced, for example, by a method for producing a composite tungsten oxide or a tungsten oxide having a Magneli phase, which is described in JP-A-2005-187323.

Element M is added to the composite tungsten oxide represented by general formula (1). Therefore, free electrons are generated, including the case of z/y = 3.0 in general formula (1), and absorption characteristics derived from free electrons appear in the near-infrared light wavelength region. It is effective as a material that absorbs infrared rays.

In particular, the element M is a group consisting of Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn, from the viewpoint of improving optical properties and weather resistance as a near-infrared absorbing material. It can be one or more types selected from.

The composite tungsten oxide represented by general formula (1) may be treated with a silane coupling agent. By treating the composite tungsten oxide represented by the general formula (1) with a silane coupling agent, the near-infrared absorbency and transparency in the visible wavelength region of the resulting printed matter can be improved.

When the value of x/y indicating the amount of addition of element M is larger than 0, a sufficient amount of free electrons are generated, and the near-infrared absorption effect can be sufficiently exhibited. Note that the amount of free electrons supplied increases as the amount of element M added increases, and the near-infrared absorption effect increases. However, the amount of free electrons supplied is usually saturated when the value of x/y is about 1. When the value of x/y is 1 or less, it is possible to prevent the formation of impurity phases in the pigment-containing layer.

The value of x/y may be 0.001 or more, 0.2 or more, or 0.30 or more, and may be 0.85 or less, 0.5 or less, or 0.35 or less. The value of x/y may in particular be approximately 0.33.

In general formulas (1) and (2), the value of z/y indicates the level of control of the amount of oxygen. In the composite tungsten oxide represented by the general formula (1), when the value of z/y satisfies the relationship 2.2≦z/y<3.0, the tungsten oxide represented by the general formula (2) The same oxygen control mechanism as in oxides works. In addition to this, in the composite tungsten oxide represented by the general formula (1), even when z/y=3.0, free electrons are supplied by addition of the element M. In general formula (1), the value of z/y may satisfy the relationship of 2.45≦z/y≦3.0.

The composite tungsten oxide represented by the general formula (1) preferably includes or consists of a hexagonal crystal structure. When the composite tungsten oxide represented by the general formula (1) has a hexagonal crystal structure, the pigment's transmission in the visible light wavelength region becomes large, and the absorption in the near-infrared light wavelength region becomes large. The cations of element M are arranged in the voids of the hexagonal crystal.

Generally, when an element M having a large ionic radius is added, hexagonal crystals are formed. Specifically, when an element with a large ionic radius such as Cs, K, Rb, Tl, In, Ba, Sn, Li, Ca, Sr, or Fe is added, hexagonal crystals are likely to be formed. However, the element M in the composite tungsten oxide represented by the general formula (1) is not limited to these elements, and the additive element M is present in the hexagonal void formed by ₆ units of WO. All you have to do is stay there.

When the composite tungsten oxide represented by the general formula (1) having a hexagonal crystal structure has a uniform crystal structure, the amount of the additive element M added is 0.2 or more in terms of x/y. It can be 0.5 or less, 0.30 or more and 0.35 or less, particularly about 0.33. It is considered that when the value of x/y is about 0.33, the additive element M is arranged in substantially all the hexagonal voids.

Moreover, other than hexagonal crystal, tetragonal crystal or cubic crystal tungsten bronze may be used. In the composite tungsten oxide represented by the general formula (1), the absorption position in the near-infrared wavelength region tends to change depending on the crystal structure, and the absorption position is longer in the order of cubic, tetragonal, and hexagonal. There is a tendency to move towards the wavelength side. Additionally, the following order of absorption in the visible wavelength region is hexagonal, tetragonal, and cubic. Therefore, if it is desired to transmit more light in the visible wavelength region and absorb more light in the near-infrared wavelength region, hexagonal tungsten bronze may be used.

In tungsten oxide having a Magneli phase represented by general formula (2), the so-called "Magneli phase" in which the value of z/y satisfies the relationship of 2.45≦z/y≦2.999 has stability. It becomes a pigment with high absorption characteristics in the near-infrared light wavelength region.

The composite tungsten oxide represented by the general formula (1) and the tungsten oxide having the Magneli phase represented by the general formula (2) greatly absorb light in the near-infrared light wavelength region, especially around a wavelength of 1000 nm. In many cases, the transmitted color tone ranges from blue to green.

The dispersed particle size of the tungsten-based infrared absorbing pigment used in the invisible light reading ink is not particularly limited, and can be appropriately selected depending on the intended use of the formed ink.

When it is desired to form an ink having transparency, it is preferable to use a tungsten-based infrared absorbing pigment having a volume average dispersed particle size of 2000 nm or less. If the dispersed particle size is 2000 nm or less, the difference between the peak of transmittance (reflectance) in the visible wavelength region and the bottom of absorption in the near-infrared wavelength region becomes large, so the transparency in the visible wavelength region becomes large. It becomes a near-infrared absorbing pigment. Furthermore, particles with a dispersed particle size smaller than 2000 nm do not completely block light due to scattering, so it is possible to maintain visibility in the visible wavelength region and at the same time efficiently maintain transparency. .

Furthermore, when emphasis is placed on transparency in the visible wavelength region, it is preferable to consider scattering by particles. Specifically, the volume average dispersed particle size of the tungsten-based infrared absorbing pigment is preferably 200 nm or less, and may further be 100 nm or less, 50 nm or less, or 30 nm or less.

When the dispersed particle diameter of the tungsten-based infrared absorbing pigment is 200 nm or less, geometric scattering or Mie scattering is reduced, resulting in a Rayleigh scattering region. In the Rayleigh scattering region, scattered light is reduced in inverse proportion to the sixth power of the dispersed particle size, so as the dispersed particle size decreases, scattering decreases and transparency improves. Furthermore, when the dispersed particle size of the tungsten-based infrared absorbing pigment is 100 nm or less, the amount of scattered light becomes extremely small. Therefore, from the viewpoint of avoiding light scattering, it is preferable that the dispersed particle diameter is small.

On the other hand, if the dispersed particle size of the tungsten-based infrared absorbing pigment is 1 nm or more, 3 nm or more, 5 nm or more, or 10 nm or more, industrial production tends to be easier.

The volume-average dispersed particle size of tungsten-based infrared absorbing pigments can be determined using Microtrack, a dynamic light scattering method that irradiates fine particles undergoing Brownian motion with a laser beam and determines the particle size from the light scattering information obtained. It can be measured using a particle size distribution meter (manufactured by Nikkiso Co., Ltd.).

In the ink for reading invisible light, the content of the tungsten-based infrared absorbing pigment is not particularly limited, but the content of the tungsten-based infrared absorbing pigment is based on 100 parts by mass of the total solid content of the ink for reading invisible light. It is preferable that the pigment is contained in an amount of 20 parts by mass or less. When the content of the tungsten-based infrared absorbing pigment in the ink for invisible light reading is within this range, the dispersibility of the pigment is good, the excessive increase in ink viscosity is suppressed, and the manufacturing cost of the ink is also suppressed. .

The content of the tungsten-based infrared absorbing pigment in the invisible light reading ink is 20 parts by mass or less, 15 parts by mass or less, 14 parts by mass, 12 parts by mass, based on 100 parts by mass of the total solid content of the invisible light reading ink. The amount may be less than or equal to 10 parts by mass, less than 8 parts by mass, less than 5 parts by mass, or less than 3 parts by mass.

In addition, the content of the tungsten-based infrared absorbing pigment in the invisible light reading ink is 0.1 part by mass or more and 0.5 part by mass or more with respect to 100 parts by mass of the total solid content of the invisible light reading ink. , 1.0 parts by mass or more, 1.5 parts by mass or more, 2.0 parts by mass or more, 3.0 parts by mass or more, or 5.0 parts by mass or more.

<Ultraviolet absorbing fluorescent pigment>
The invisible light reading ink has an ultraviolet absorbing fluorescent pigment dispersed therein as an essential component. By containing an ultraviolet absorbing fluorescent pigment, the invisible light reading ink can provide printed matter having ultraviolet absorbing performance.

The ultraviolet absorbing fluorescent pigment used in the present disclosure emits visible light with a spectrum peak in blue, green, red, etc. when excited by ultraviolet light and returning to a lower energy level. In the present disclosure, the material is not particularly limited as long as it absorbs ultraviolet light and emits fluorescence, and any known pigment used in the field of ink can be used.

Further, the ultraviolet absorbing fluorescent pigment may be an organic pigment or an inorganic pigment. From the viewpoint of excellent weather resistance, it is preferable to use an inorganic pigment. On the other hand, when it is desired to ensure transparency and increase invisibility, it is preferable to use an organic pigment that emits sufficient fluorescence even when added in a small amount.

Examples of organic ultraviolet absorbing fluorescent pigments include Lumogen L Yellow, Lumogen Brilliant Yellow, and Lumogen Brilliant Green. In addition, as an inorganic fluorescent pigment, a compound represented by M-Al ₂ O ₄ (M is a compound consisting of strontium (Sr) and barium (Ba) is used as a mother crystal, and europium (Eu) is used as an activator. ) and a fluorescent pigment obtained by adding dysprosium (Dy) as a coactivator.

Commercially available products can also be used, and examples of organic UV-absorbing fluorescent pigments include Lumicol (registered trademark) 1000 (Japan Fluoro Chemical Co., Ltd., quinazolone derivative). Examples of inorganic ultraviolet absorbing fluorescent pigments include D1164 manufactured by Nemoto Tokushu Kagaku Co., Ltd.

In the non-visible light reading ink, the content of the ultraviolet absorbing fluorescent pigment is not particularly limited, and can be appropriately set depending on whether an organic pigment or an inorganic pigment is used.

The content of the ultraviolet absorbing fluorescent pigment in the invisible light reading ink is 20 parts by mass or less, 15 parts by mass or less, 14 parts by mass, 12 parts by mass, based on 100 parts by mass of the total solid content of the invisible light reading ink. part or less, 10 parts by weight or less, 8 parts by weight or less, 5 parts by weight or less, or 3 parts by weight or less. When the content of the ultraviolet absorbing fluorescent pigment in the non-visible light reading ink is within this range, the dispersibility of the pigment is good, an excessive increase in ink viscosity is suppressed, and the manufacturing cost of the ink is also suppressed.

Further, the content of the ultraviolet absorbing fluorescent pigment in the invisible light reading ink is 0.1 part by mass or more, 0.5 part by mass or more, based on 100 parts by mass of the total solid content of the invisible light reading ink. The amount may be 1.0 parts by mass or more, 1.5 parts by mass or more, 2.0 parts by mass or more, 3.0 parts by mass or more, 4.0 parts by mass or more, or 5.0 parts by mass or more.

<Ultraviolet curable urethane acrylate resin>
The invisible light reading ink contains an ultraviolet curable urethane acrylate resin as an essential component. By including the ultraviolet curable urethane acrylate resin, it is possible to provide printed matter that has ultraviolet curable performance and has excellent base resistance, particularly washing resistance.

The ultraviolet curable urethane acrylate resin used in the present disclosure is not particularly limited as long as it is a polymer having a urethane bond and an acryloyl group derived from acrylic acid.

The ultraviolet curable urethane acrylate resin has an acryloyl group in its molecular chain, so it can be cured by ultraviolet rays. Furthermore, by having a urethane bond in the molecular chain, hydrogen bonds can be formed with other molecules. As a result, it becomes possible to provide printed matter with excellent base resistance, especially washing resistance.

The acryloyl group that the ultraviolet curable urethane acrylate resin has is a group derived from acrylic acid. Acrylic acid may be monofunctional or polyfunctional.

The ultraviolet curable urethane acrylate resin used in the present disclosure preferably contains a plurality of acryloyl groups. The number of acryloyl groups that the ultraviolet curable urethane acrylate resin has may be 2 or more, 3 or more, 4 or more, 6 or more, or 9 or more.

When the number of acryloyl groups is 3 or more, crosslinking can be formed between molecules, so that base resistance, particularly washing resistance, can be further improved.

Moreover, the urethane bond that the ultraviolet curable urethane acrylate resin has is formed by reacting an isocyanate group and a hydroxy group. The urethane bond of the ultraviolet curable urethane acrylate resin used in the present disclosure may be formed from an aromatic isocyanate compound or an aliphatic isocyanate compound. But that's fine.

Further, the compound having a hydroxyl group for forming a urethane bond in the ultraviolet curable urethane acrylate resin may be either polyether-based or polyester-based, and even if it is a polymer, it may be a low molecular weight diol, etc. It may be.

That is, the ultraviolet curable urethane acrylate resin used in the present disclosure may be a polymer having a certain molecular weight, an oligomer, or a prepolymer.

In the ink for invisible light reading, the content of the ultraviolet curable urethane acrylate resin is not particularly limited, but the content of the ultraviolet curable urethane acrylate resin is based on 100 parts by mass of the total solid content of the ink for invisible light reading. Preferably, the resin is contained in an amount of 1 to 50 parts by mass.

If the ratio of the ultraviolet curable urethane acrylate resin to 100 parts by mass of the total solid content of the invisible light reading ink is within the above range, the invisible light reading ink will have an appropriate viscosity and sufficient ultraviolet curing performance. At the same time, it becomes possible to provide printed matter with sufficient base resistance, particularly excellent washing resistance.

In addition, the content of the ultraviolet curable urethane acrylate resin in the invisible light reading ink is 2 parts by mass or more, 3 parts by mass or more, and 5 parts by mass with respect to 100 parts by mass of the total solid content of the invisible light reading ink. The amount may be 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more.

The content of the ultraviolet curable urethane acrylate resin in the invisible light reading ink is 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, based on 100 parts by mass of the total solid content of the invisible light reading ink. It may be 30 parts by mass or less, or 25 parts by mass or less.

Further, in the invisible light reading ink, the amount of the ultraviolet curable urethane acrylate resin is preferably 1 to 150 parts by mass based on 100 parts by mass of the ultraviolet curable acrylic resin, which is one of the essential components described below. .

If the blending amount of the ultraviolet curable urethane acrylate resin per 100 parts by mass of the ultraviolet curable acrylic resin is within the above range, the increase in viscosity caused by the ultraviolet curable urethane acrylate resin in the non-visible light reading ink is suppressed. .

The blending amount of the ultraviolet curable urethane acrylate resin with respect to 100 parts by weight of the ultraviolet curable acrylic resin is 2 parts by mass or more, 3 parts by mass or more, 5 parts by mass or more, 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more. , 30 parts by mass or more, 40 parts by mass or more, 50 parts by mass or more, 60 parts by mass or more, 70 parts by mass or more, 80 parts by mass or more, 90 parts by mass or more, 100 parts by mass or more, 110 parts by mass or more, 120 parts by mass or more , 130 parts by mass or more, 140 parts by mass or more, or 150 parts by mass or more.

The blending amount of the ultraviolet curable urethane acrylate resin with respect to 100 parts by weight of the ultraviolet curable acrylic resin is 200 parts by mass or less, 190 parts by mass or less, 180 parts by mass or less, 170 parts by mass or less, 160 parts by mass or less, 150 parts by mass. 140 parts by mass or less, 130 parts by mass or less, 120 parts by mass or less, 100 parts by mass or less, 90 parts by mass or less, 80 parts by mass or less, 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less; Good too.

<Ultraviolet curable acrylic resin that does not contain urethane bonds>
The invisible light reading ink contains as an essential component an ultraviolet curable acrylic resin that does not contain urethane bonds. The ultraviolet curable acrylic resin that does not contain a urethane group has the effect of dispersing the tungsten-based infrared absorbing pigment and the ultraviolet absorbing fluorescent pigment well, and suppressing the increase in viscosity caused by the ultraviolet curable urethane acrylate resin.

Therefore, in the invisible light reading ink, an ultraviolet curable acrylic resin that does not contain a urethane bond has a low viscosity and is a material that is highly compatible with the ultraviolet curable urethane acrylate resin.

The ultraviolet curable acrylic resin that does not contain urethane bonds is preferably a monomer, oligomer, or prepolymer, and monomers are particularly preferred, because it needs to have a low viscosity.

The monomer used in the present disclosure to form the UV-curable acrylic resin that does not contain urethane bonds is not particularly limited, and known acrylic monomers used in UV-curable inks may be used. I can do it.

Examples of such acrylic monomers include acrylates having ethylenically unsaturated bonds, and in the present disclosure, they may be either monofunctional acrylates or polyfunctional acrylates. It is also possible to use these together.

Examples of monofunctional acrylates include caprolactone acrylate, isodecyl acrylate, isooctyl acrylate, isomyristyl acrylate, isostearyl acrylate, 2-ethylhexyl-diglycol diacrylate, 2-hydroxybutyl acrylate, and 2-acryloyloxyethyl hexahydro. Phthalic acid, neopentylfuricol acrylic acid benzoate, isoamyl acrylate, lauryl acrylate, stearyl acrylate, butoxyethyl acrylate, ethoxy-diethylene glycol acrylate, methoxy-triethylene glycol acrylate, methoxy-polyethylene glycol acrylate, methoxydipropylene glycol acrylate, Phenoxyethyl acrylate, phenoxy-polyethylene glycol acrylate, nonylphenol ethylene oxide adduct acrylate, tetrahydrofurfuryl acrylate, isobonyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2- Examples include acryloyloxyethyl-succinic acid, 2-acryloyloxyethyl-phthalic acid, and 2-acryloyloxyethyl-2-hydroxyethyl-phthalic acid.

Examples of the bifunctional acrylate include hydroxypivalic acid neopentyl glycol diacrylate, alkoxylated hexanediol diacrylate, polytetramethylene glycol diacrylate, trimethylolpropane acrylic acid benzoate, diethylene glycol diacrylate, triethylene glycol diacrylate, Tetraethylene glycol diacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, neopentyl glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butane Examples include diol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, dimethylol-tricyclodecane diacrylate, and bisphenol A diacrylate.

Examples of trifunctional or higher functional acrylates include ethoxylated isocyanuric acid triacrylate, ε-caprolactone modified tris-(2-acryloxyethyl) isocyanurate, pentaerythritol triacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, Examples include pentaerythritol tetraacrylate, dipentaerythritol polyacrylate, ethoxylated pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

Furthermore, examples of acrylic oligomers include polyester acrylate, epoxy acrylate, silicone acrylate, polybutadiene acrylate, and the like.

<Other ingredients>
In addition to the essential components of tungsten-based infrared-absorbing pigments, ultraviolet-absorbing fluorescent pigments, ultraviolet-curable urethane acrylate resins, and ultraviolet-curable acrylic resins that do not contain urethane groups, the invisible light reading ink contains any other optional ingredients. It may contain ingredients.

Other components are not particularly limited, and known substances used in the field of ultraviolet curable inks can be used. Examples include photopolymerization initiators, diluting solvents, dispersants, coupling agents, viscosity modifiers, surface tension modifiers, pH modifiers, and the like.

(Photopolymerization initiator)
A photopolymerization initiator is a compound that generates radicals such as active oxygen when exposed to ultraviolet rays. When using a photopolymerization initiator in an ink for invisible light reading, the type of UV-curable urethane acrylate resin, which is an essential component, and the type of UV-curable acrylic resin that does not contain urethane groups, if it can be photopolymerized. is not particularly limited, and can be appropriately selected from photopolymerization initiators conventionally used in ultraviolet curable inks.

Examples of the photopolymerization initiator include acetophenone, α-aminoacetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and benzyldimethyl ketal. , 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone, 4-(2- hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, 2-benzyl-2- Acetophenones such as dimethylamino-1-(4-morpholinophenyl)-butanone; beyzoin, beyzoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, beyzoin isopropyl ether, benzoin-n-butyl ether, benzoin Benzoins such as isobutyl ether, benzoin dimethyl ketal, benzoin peroxide; Acylphophine oxides such as 2,4,6-trimethoxybenzoindiphenylphosphine oxide; Benzyl and methylphenyl-glyoxy esters; Benzophenone, methyl-4- Phenylbenzophenone, o-benzoylbenzoate, 2-chlorobenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, acrylic-benzophenone, 3,3'4,4'-tetra Benzophenones such as (t-butylperoxycarbonyl)benzophenone and 3,3'-dimethyl-4-methoxybenzophenone; 2-methylthioxanthone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2 -thioxanthone such as chlorothioxanthone and 2,4-dichlorothioxanthone; aminobenzophenones such as Michler's ketone and 4,4'-diethylaminobenzophenone; tetramethylthiuram monosulfide; azobisisobutyronitrile; di-tert-butyl peroxide ; 10-butyl-2-chloroacridone; 2-ethylanthraquinone; 9,10-phenanthrenequinone; camphorquinone; titanocenes, and combinations thereof.

Further, a photopolymerization initiation aid such as ethyl 4-dimethylaminobenzoate or isoamyl 4-dimethylaminobenzoate may be used in combination with the photopolymerization initiator.

The amount of the photopolymerization initiator to be used is not particularly limited, but for example, 1 part by mass for a total of 100 parts by mass of the UV-curable urethane acrylate resin and the UV-curable acrylic resin that does not contain urethane groups. parts or more, 2 parts or more, 3 parts or more, 4 parts or more, or 5 parts by mass or more, and 20 parts or less, 15 parts or less, 10 parts or less, 8 parts by mass or less, or It may be 6 parts by mass or less.

(solvent)
The invisible light reading ink may contain a solvent for the purpose of dispersion, viscosity adjustment, etc. The solvent is not particularly limited as long as it can disperse or dissolve the materials contained in the ink.

For example, alcohols such as ethanol, propanol, butanol, isopropyl alcohol, isobutyl alcohol, and diacetone alcohol; ethers such as methyl ether, ethyl ether, and propyl ether; esters such as ethyl acetate; acetone, methyl ethyl ketone, diethyl ketone, and cyclohexanone Ketones such as , ethyl isobutyl ketone, methyl isobutyl ketone; Aromatic hydrocarbons such as toluene, xylene, benzene; Aliphatic hydrocarbons such as n-hexane, heptane, cyclohexane; Propylene glycol monomethyl ether acetate, propylene glycol monoethyl Various organic solvents can be mentioned, such as glycol ethers such as ethers.

When a solvent is used in the non-visible light reading ink, it may be a single solvent or a mixed solvent of two or more solvents. Furthermore, when preparing the ink composition, the solvents used for dispersing or diluting each component may be directly brought in and mixed. Furthermore, after preparing the composition to become the ink, a diluting solvent may be added for the purpose of reducing the viscosity of the ink composition.

For example, a first solvent that constitutes a dispersion containing a tungsten-based infrared absorbing pigment, a second solvent that constitutes an ultraviolet curable urethane acrylate resin solution, and a solution of an ultraviolet curable acrylic resin that does not contain a urethane group. Examples include an embodiment in which a third solvent is mixed, and each solvent may be the same or different, and furthermore, it may be one type of solvent alone or a mixed solvent of two or more types. .

The content of the solvent in the invisible light reading ink is not particularly limited, but for example, 0.1 parts by mass or more, 0.5 parts by mass or more with respect to 100 parts by mass of the invisible light reading ink. , may be 1 part by mass or more, 3 parts by mass or more, or 5 parts by mass or more, and 50 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, 5 parts by mass. Below, the amount may be 3 parts by mass or less, or 1 part by mass or less.

(dispersant)
In order to improve the dispersibility of the tungsten-based infrared absorbing pigment in the ink, the ink for reading invisible light may contain a dispersant. Although the dispersant is not particularly limited, examples thereof include compounds having functional groups such as amine, hydroxyl group, carboxyl group, and epoxy group. These functional groups have the function of uniformly dispersing the tungsten-based infrared-absorbing pigment in the ink by adsorbing to the surface of the tungsten-based infrared-absorbing pigment and preventing aggregation of the tungsten-based infrared-absorbing pigment.

The content of the dispersant in the ink is 0.1 parts by mass or more, 0.3 parts by mass or more, 0.5 parts by mass or more, 1.0 parts by mass or more, based on 100 parts by mass of the invisible light reading ink. It may be 1.5 parts by mass or more, or 2.0 parts by mass or more, and 15 parts by mass or less, 10 parts by mass or less, 8.0 parts by mass or less, 5.0 parts by mass or less, 3.0 parts by mass or less. , 2.0 parts by mass or less, or 1.5 parts by mass or less.

《Method for producing ink for invisible light reading》
The method for manufacturing the invisible light reading ink is not particularly limited, and any known method used for forming ink can be applied.

For example, a dispersion containing a tungsten-based infrared absorbing pigment and a first solvent, a powder that is an ultraviolet absorbing fluorescent pigment, and a composition containing an ultraviolet curable urethane acrylate resin or the resin and a second solvent; An example is a method of mixing with an ultraviolet curable acrylic resin that does not contain urethane groups.

Furthermore, for the purpose of lowering the viscosity of the ink, a step of adjusting the viscosity by mixing a diluting solvent may be included.

In this case, the diluting solvent is prepared by adding a tungsten-based infrared absorbing pigment dispersion, an ultraviolet curable urethane acrylate resin or a composition containing the resin and a second solvent, and urethane to the ink composition. It may be mixed with at least one of the group-free ultraviolet curable acrylic resins, or it may be mixed into the composition after preparing the composition to become the ink.

《Printing method for invisible light reading ink》
The printing method of the invisible light reading ink is not particularly limited. It can be used as a general printing ink, for example, flexographic printing ink, letterpress printing ink, offset printing ink, intaglio printing ink, gravure printing ink, screen printing ink, inkjet printing ink, etc.

Among these, it is preferable to use it as an offset printing ink, an intaglio printing ink, a screen printing ink, or an inkjet printing ink because it is used for determining the authenticity of printed matter.

In particular, the ink for invisible light reading can be an inkjet ink that uses an inkjet head compatible with high viscosity liquids, which makes it possible to form fine patterns even with high viscosity inks.

Hereinafter, the invisible light reading ink used in the printed matter of the present disclosure will be described in more detail with reference to Examples and Comparative Examples, but the present disclosure is not limited thereto.

<Materials>
The materials used in Examples, Comparative Examples, etc. are shown below.
(1) Tungsten-based infrared absorbing pigment - Cesium tungsten oxide (CWO) dispersion (YMS-01A-2, Sumitomo Metal Mining Co., Ltd.): CWO content 25% by mass
Hexagonal Cs _0.33 WO ₃ : 25 mass% by weight
Propylene glycol monomethyl ether acetate: 58.9% by mass
Dipropylene glycol monomethyl ether: 1.86% by mass
Butyl acetate: 1.74% by mass
Dispersant: 12.5% by mass

(2) Ultraviolet absorbing fluorescent pigment - Organic fluorescent pigment (Lumicol (registered trademark) 1000, Nippon Fluoro Chemical, quinazolone derivative, white powder)

(3) Ultraviolet curable urethane acrylate resin - Luxidia (registered trademark) WLS-373, DIC Corporation: 6 acryloyl groups/100% resin content in 1 molecule
・Luxidia (registered trademark) V-4260, DIC Corporation: 3 acryloyl groups/in 1 molecule, resin content of 99% or more ・Luxidia (registered trademark) V-4263, DIC Corporation: 3 acryloyl groups/in 1 molecule , resin content of 99% or more

(4) UV-curable acrylic resin that does not contain urethane groups - Acrylic monomer (BESTCURE UV monomer for dispersion, T&K TOKA Co., Ltd.): 100% photosensitive monomer

(5) Acrylic resin soluble in solvent - Acrylic resin (Acridic (registered trademark) A-814, DIC Corporation)
Acrylic resin (Tg: 85°C): 50% by mass
Toluene: 42.5% by mass
Ethyl acetate: 7.5% by mass

(6) Photopolymerization initiator - Photoradical initiator (IRGACURE (registered trademark) 500, BASF Corporation)

<Example 1>
(A) 10.0 g of cesium tungsten oxide (CWO) dispersion (YMS-01A-2, Sumitomo Metal Mining Co., Ltd.) as a tungsten-based infrared absorbing pigment, (B) an ultraviolet absorbing fluorescent pigment (UV-FP) 2.5 g of organic fluorescent pigment (Lumicol (registered trademark) 1000, Nippon Fluoro Chemical, quinazolone derivative, white powder), (C) ultraviolet curable urethane acrylate resin, Luxidia (registered trademark) WLS-373 (DIC) (D) 30.0 g of acrylic monomer (BESTCURE UV monomer for dispersion, T&K TOKA Co., Ltd.) as an ultraviolet curable acrylic resin that does not contain urethane groups, and (G) start photopolymerization. IRGACURE (registered trademark) 500 (BASF Corporation) was mixed as an agent to prepare an ink for reading invisible light.

Note that (G) the photopolymerization initiator is added in an amount of 4 parts by mass to a total of 100 parts by mass of (C) the ultraviolet curable urethane acrylate resin and the ultraviolet curable acrylic resin that does not contain urethane groups. did.

<Examples 2 to 8 and Comparative Examples 1 to 4>
Inks of Comparative Examples 1 to 4 were prepared by changing the blending ratio of the components as shown in Table 1. The blending amount of (G) photopolymerization initiator is the same as in Example 1, and the total amount of (C) ultraviolet curable urethane acrylate resin and (D) ultraviolet curable acrylic resin not containing urethane groups is 100 mass. parts, the amount was 4 parts by mass.

In Comparative Example 1, the cesium tungsten oxide (CWO) dispersion (YMS-01A-2, Sumitomo Metal Mining Co., Ltd.) and the UV-curable acrylic monomer did not mix, resulting in separation and precipitation of cesium tungsten oxide. did. For this reason, it could not be used as an ink.

<Evaluation>
(Preparation of printed matter)
As base materials, polyethylene terephthalate film (CD942, KOLON INDUSTRIES, INC.) and paper (OCR paper, Oji Paper Co., Ltd.) were prepared. The inks prepared in each example and comparative example were applied to each base material using a wire bar at a coating weight of 7.5 g/m ² , and after heat drying at 80°C, the inks were cured by ultraviolet irradiation. , got the print. The obtained printed matter was cut into a size of 2.5 cm x 4 cm.

(Measurement of infrared reflectance)
The infrared reflectance of the obtained printed matter was measured in accordance with JIS K 0115 using a UV-vis reflectance spectrometer (UV-visible near-infrared spectrophotometer UH4150, Hitachi High-Tech Science Co., Ltd.). For each test piece, the number of measurements was three times (N number = 3). Note that the lower the infrared reflectance value, the higher the infrared absorption rate. Table 1 shows the infrared reflectance at a wavelength of 1000 nm.

(Measurement of fluorescence intensity)
In accordance with JIS K 0120, the obtained printed matter was irradiated with light at a wavelength of 365 nm, and the fluorescence intensity was measured using FP-6600 manufactured by JASCO Corporation. The fluorescence intensity was calculated from the value at a wavelength of 522 nm in the spectrum. For each test piece, the number of measurements was three times (N number = 3). The results are shown in Table 1.

Note that the fluorescence intensity measurements in Examples 5, 6, and 8 were performed using a light-reducing plate with a light transmittance of about 14% in order to match the measurement range of the measuring instrument used.

(Washing resistance test)
Subsequently, a wash resistance test was conducted on the produced printed matter. Specifically, the printed matter was immersed in an aqueous solution at a temperature of 90° C. for 30 minutes. The aqueous solution was prepared by adding 0.5% by mass of laundry detergent (Attack (trademark), Kao Corporation) and 1% by mass of sodium carbonate to distilled water. After soaking, it was washed with water and dried.

(Measurement of infrared reflectance after washing resistance test)
The infrared reflectance of the printed matter after the washing resistance test was measured in the same manner as above. Table 1 shows the infrared reflectance at a wavelength of 1000 nm.

(Residual rate of tungsten-based infrared absorbing pigment after washing resistance test)
Using the infrared reflectance at a wavelength of 1000 nm before the wash resistance test and the infrared reflectance at a wavelength of 1000 nm after the wash resistance test, the residual rate of the tungsten-based infrared absorbing pigment after the wash resistance test was determined by the following formula. . The results are shown in Table 1. Note that the residual rate of the obtained tungsten-based infrared absorbing pigment serves as an index for determining how well the infrared absorbing function was maintained.
Pigment residual rate (%) = (100 - infrared reflectance after test) / (100 - infrared reflectance before test) x 100

(Infrared camera observation)
The printed matter after the washing resistance test was observed with an infrared camera. During observation, an infrared LED with a wavelength of 940 nm was used for infrared illumination, and a filter was used to cut light with a wavelength of 820 nm or less. Observation was made under observation conditions of 250,000 pixels, a lens angle of view of 67 degrees horizontally and 47 degrees vertically, and a drawing area of 22 x 18 mm, and the evaluation was made using the following evaluation criteria. The results are shown in Table 1.
AA: The coated area can be distinguished very clearly.
A: The coated area can be clearly identified.
B: The coated area can be determined by directly comparing and observing the non-coated area and the coated area.
C: The coated area cannot be determined even by direct comparative observation of the non-coated area and the coated area.

(Measurement of fluorescence intensity after washing resistance test)
The fluorescence intensity of the printed matter after the washing resistance test was measured in the same manner as above. The results are shown in Table 1.

(Residual rate of ultraviolet absorbing fluorescent pigment after washing resistance test)
Using the fluorescence intensity at a wavelength of 522 nm before the washing resistance test and the fluorescence intensity at a wavelength of 522 nm after the washing resistance test, the residual rate of the ultraviolet absorbing fluorescent pigment after the washing resistance test was determined by the following formula. The results are shown in Table 1. Note that the residual rate of the obtained ultraviolet absorbing fluorescent pigment serves as an index for determining how long the ultraviolet absorbing fluorescent pigment was maintained.
Fluorescence intensity residual rate (%) = (value after test) / (value before test) x 100

(Ultraviolet irradiation observation)
The printed matter after the washing resistance test was irradiated with UV light having a wavelength of 375 nm, and the state of fluorescence was visually judged using the following evaluation criteria. The results are shown in Table 1.
A: The coated area can be clearly identified.
C: The coated area cannot be determined even by direct comparative observation of the non-coated area and the coated area.

Comparative Example 2, which is an ink containing only an ultraviolet-absorbing fluorescent pigment, has very good fluorescence intensity even after the washing resistance test, but ink containing an ultraviolet-absorbing fluorescent pigment and a tungsten-based infrared-absorbing pigment In Comparative Example 3, which is an ink, the fluorescence intensity after the washing resistance test was significantly reduced. That is, it can be seen that the washing resistance of the ultraviolet-absorbing fluorescent pigment is significantly reduced by the presence of the tungsten-based infrared-absorbing pigment.

However, Examples 1 to 8 containing ultraviolet curable urethane acrylate resins maintained both infrared absorption performance and fluorescence intensity even after the washing resistance test. This is because hydrogen bonds are formed by the urethane bonds of the UV-curable urethane acrylate resin, and a resin film is formed by the UV-curable urethane acrylate resin around the tungsten-based infrared-absorbing pigment and around the UV-absorbing fluorescent pigment. It is thought that this was due to an accident.

<Reference Examples 1 to 10, Comparative Reference Examples 1 to 3>
Inks of Reference Examples 1 to 10 and Comparative Reference Examples 1 to 3 were prepared by changing the blending ratio of the components as shown in Table 2. As in Example 1, the amount of the photopolymerization initiator is 4 parts by mass based on the total of 100 parts by mass of the UV-curable urethane acrylate resin and the UV-curable acrylic resin that does not contain urethane groups. I did it like that.

The solvent-soluble acrylic resin (Acridic (registered trademark) A-814, DIC Corporation) used in Comparative Reference Example 2 had a high viscosity, so it was diluted with the same amount of ethyl acetate, and then It was mixed with a cesium tungsten oxide (CWO) dispersion (YMS-01A-2, Sumitomo Metal Mining Co., Ltd.).

In Comparative Reference Example 1, the cesium tungsten oxide (CWO) dispersion (YMS-01A-2, Sumitomo Metal Mining Co., Ltd.) and the ultraviolet curable acrylic monomer did not mix, and separation occurred, resulting in cesium tungsten oxide It settled. For this reason, it became impossible to use it as an ink.

In Comparative Reference Example 3, since the proportion of the ultraviolet curable urethane acrylate resin was high, the viscosity of the resulting composition was too high to be used as an ink.

<Evaluation>
A printed matter was produced in the same manner as in Example 1, and the infrared reflectance was measured before and after the washing resistance test, and the residual rate of the tungsten-based infrared absorbing pigment after washing was measured. Calculated. Further, in the same manner as in Example 1, the printed matter after the washing resistance test was observed with an infrared camera and evaluated. The results are shown in Table 2.

(Measurement of viscosity)
The viscosity of the obtained ink was measured using a tuning fork vibration viscometer (SV-1A (natural frequency 30Hz), A&D Co., Ltd.) at the temperatures shown in Table 2 in accordance with JIS Z 8803. Measured at Note that the measurement sample was 5 mL. The results are shown in Table 2.

The residual rates of tungsten-based infrared absorbing pigments in Reference Examples 1 to 10 are higher in both polyethylene terephthalate film coating and OCR coating than in Comparative Reference Example 2. The results showed that the results had a significantly high effect on washing resistance. This is thought to be because hydrogen bonds are formed by the urethane bonds of the ultraviolet curable urethane acrylate resin, and a strong resin film is formed around the tungsten-based infrared absorbing pigment by the ultraviolet curable urethane acrylate resin.

Comparison of Reference Example 1 and Reference Examples 2 and 3 shows that the more acryloyl groups the ultraviolet curable urethane acrylate resin has, the better the tungsten-based infrared absorbing properties for both polyethylene terephthalate film coating and OCR coating. It can be seen that the residual rate of pigment is high. This is thought to be because UV-curable urethane acrylate resins with a large number of acryloyl groups have a higher crosslinking density when printed matter is formed, and therefore have improved wash resistance.

Further, the ink of the reference example having a viscosity of 60 mPa·s or less could be used as an inkjet ink without any problems.

1 First identification code 1' Pattern 2 Second identification code 3, 3' Third identification code 100, 101, 102 Authenticity determination terminal of the present disclosure 200 Server used in the authenticity determination system of the present disclosure

Claims (14)

A terminal for determining the authenticity of a printed matter, and a device configured to be able to communicate with the terminal for determining authenticity, receiving the code information from the terminal for determining authenticity, determining the authenticity based on the received code information, and determining the result of the authenticity determination. a server that transmits the information to the authentication terminal;
An authentication system comprising:
The printed matter is
It has a printed part for visible light reading printed with ink for reading visible light, and a printed part for invisible light reading printed with ink for reading invisible light,
The visible light reading printing section and the non-visible light reading printing section at least partially overlap to form an overlapping printing section,
A first identification code formed by the visible light reading print section, a second identification code formed by the non-visible light reading print section, and a third identification code formed by the overlapping print section. at least two of the identification codes;
The invisible light reading ink is
Tungsten-based infrared absorbing pigment,
UV-absorbing fluorescent pigments,
UV-curable urethane acrylate resin, UV-curable acrylic resin that does not contain urethane bonds,
including;
The authenticity determination terminal is
a visible light image acquisition unit that acquires a visible light image of the visible light reading printing unit;
a non-visible light image acquisition unit that obtains a non-visible light image of the non-visible light reading printing unit;
a first processing unit that recognizes a first identification code from the visible light image to obtain first code information; a first processing unit that recognizes a second identification code from the non-visible light image to obtain second code information; at least two of the third processing unit that recognizes the third identification code from the visible light image and the non-visible light image to obtain third code information; It has a display section that displays the authenticity determination result based on the
The invisible light image acquisition unit obtains at least one of an infrared image and an ultraviolet fluorescence image as the invisible light image.
Authenticity determination system. The system according to claim 1, wherein the server further records information regarding the authenticity determination in a database in association with the received code information. 2 or more of the authentication terminals,
A first authentication terminal of the authentication terminals obtains only at least one of an infrared image and an ultraviolet fluorescence image as the non-visible light image.
A second authentication terminal among the authentication terminals selects both the infrared image and the ultraviolet fluorescence image, or the first authentication of the infrared image and the ultraviolet fluorescence image as the non-visible light image. Obtain the one that is not obtained on the judgment terminal,
The system according to claim 1 or 2. The printed matter has at least the third identification code, and the authentication terminal has at least the third processing section.
The system according to claim 1 or 2. The system according to claim 1 or 2, wherein the visible light reading ink is a non-infrared absorbing ink. The system according to claim 1 or 2, wherein the ultraviolet curable urethane acrylate resin is contained in an amount of 1 to 150 parts by mass based on 100 parts by mass of the ultraviolet curable acrylic resin. The system according to claim 1 or 2, wherein the tungsten-based infrared absorbing pigment is contained in an amount of 20 parts by mass or less based on 100 parts by mass of the total solid content in the invisible light reading ink. The system according to claim 1 or 2, wherein the ultraviolet absorbing fluorescent pigment is contained in an amount of 20 parts by mass or less based on 100 parts by mass of total solid content in the invisible light reading ink. The system according to claim 1 or 2, wherein the ultraviolet curable urethane acrylate resin is contained in 1 to 50 parts by mass based on 100 parts by mass of total solid content in the invisible light reading ink. The system according to claim 1 or 2, wherein the ultraviolet curable urethane acrylate resin contains a plurality of acryloyl groups. The tungsten-based infrared absorbing pigment is
General formula (1): M _x W _y O _z
{In the formula, M is H, He, alkali metal element, alkaline earth metal element, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, One or more elements selected from the group consisting of Re, Be, Hf, Os, Bi, and I, W is tungsten, O is oxygen, and x, y, and z are each positive numbers. , 0<x/y≦1 and 2.2≦z/y≦3.0}
Composite tungsten oxide represented by, or
General formula (2): W _y O _z
{In the formula, W is tungsten, O is oxygen, y and z are each positive numbers, and 2.45≦z/y≦2.999}
Tungsten oxide having a Magnelli phase represented by
The system according to claim 1 or 2, wherein the system is at least one selected from the following. The system according to claim 1 or 2, wherein the invisible light reading printing section is inkjet printed. The authentication terminal according to claim 1 or 2. Authenticity determination software for the authenticity determination terminal according to claim 13,
causing the visible light image acquisition unit to acquire a visible light image of the visible light reading printing unit;
causing the invisible light image acquisition section to acquire a non-visible light image of the invisible light reading printing section, and causing the first processing section to recognize a first identification code from the visible light image to generate a first identification code. acquiring code information, causing the second processing unit to recognize a second identification code from the non-visible light image and acquiring second code information, and causing the third processing unit to recognize the second identification code from the invisible light image; performing at least two of the following: recognizing a third identification code from an image and the non-visible light image to obtain third code information;
Authenticity determination software.

Images