TWI664095B - Latent image printed matter of solid formulation, imaging method thereof and method for inspecting edible material - Google Patents

Abstract

The invention provides a latent image printed matter of a solid preparation and a photographic method of the latent image printed matter of the solid preparation. The latent image printed matter of the solid preparation is provided with a latent image on a surface, and the latent image can be developed by ultraviolet radiation in a specific wavelength region. Into.

The latent image printed matter of the solid preparation of the present invention is a latent image printed matter of the solid preparation 10 provided with the latent image on at least a part of the surface; it is characterized by having at least: a latent image area A formed by the latent image ink layer 11. The latent image, the aforementioned latent image ink layer 11 absorbs ultraviolet rays in a wavelength range of 200 nm to 400 nm; and the non-latent image region B, at least reflects and / or emits ultraviolet light in the aforementioned wavelength region; and When the area A and the non-latent image area B are irradiated with visible light, the difference between the order value of the latent image area A and the non-latent image area B is less than 5, and the exposure of the latent image area A and the non-latent image area B includes at least the above In the case of the ultraviolet light in the wavelength region, the difference between the order values of the latent image region A and the non-latent image region B is 5 or more.

Description

   Latent image printed matter of solid preparation, photographic method of latent image printed matter of solid preparation, and inspection method of edible matter   

The invention relates to a latent image printed matter of a solid preparation and a photographic method of a latent image printed matter of a solid preparation. More specifically, the present invention relates to a latent image printed matter of a solid preparation printed with a latent image and a latent image printed matter of a solid preparation. In the method, the aforementioned latent image can be developed by ultraviolet irradiation in a specific wavelength region. In addition, the present invention relates to a method for inspecting an edible substance, and more specifically, it relates to an inspection method for an edible substance having a latent image printed on the edible substance such as a pharmaceutical product. The area is developed by ultraviolet irradiation.

In recent years, there has been an increase in the number of pharmaceutical products such as pharmaceuticals that are indicated by direct inkjet printing. In particular, the inkjet method can achieve variable printing, that is, different information is printed for each recorded medium. Therefore, in addition to the drug name, for the tablet, an attempt has been made to variably print the batch number of the tablet or Expiry date of tablets, security code to prevent counterfeit medicines, etc.

On the other hand, product information other than the name of the medicament is usually information that does not require general consumer or patient knowledge. Therefore, for example, it is preferable that it is generally not recognized by ordinary consumers under visible light. Examples of inks that can realize such printing include edible inks, which contain riboflavin and the like, and can recognize printed images only when the hue changes when they are irradiated with ultraviolet rays ( Refer to the following patent document 1). In addition, an ink obtained by dissolving an edible fluorescent dye in a solvent or a lake pigment ink is used to dissolve the fluorescent dye insolubilizing the solvent and dissolve it as a lake organic pigment. Made in solvent.

However, these inks have a problem that they have poor light resistance compared to edible inks using inorganic pigments such as iron oxide.

[Prior technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2011-241312.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide a latent image print of a solid preparation and a photographic method of the latent image print of the solid preparation. The solid preparation is provided with a latent image on the surface, and the latent image can be borrowed. It is developed by irradiation with ultraviolet rays in a specific wavelength region. In addition, a second object of the present invention is to provide a method for inspecting an edible substance, and for an edible substance provided with a latent image, the latent image can be easily inspected or discriminated at a low cost.

In order to solve the above-mentioned problems, the inventors of the present case studied the latent image printed matter of the solid preparation, the photographic method of the latent image printed matter of the solid preparation, and the inspection method of the edible matter. The above problems have thus completed the present invention.

That is, in order to solve the above-mentioned problem, in the latent image print of the solid preparation of the present invention, at least a portion of the surface of the solid preparation is provided with a latent image; the latent image print of the solid preparation is characterized by having at least: a latent image region, The aforementioned latent image is formed by a latent image ink layer that absorbs ultraviolet rays in a wavelength range of 200 nm to 400 nm; and a non-latent image region that reflects at least the ultraviolet rays in the above wavelength region and / or emits fluorescence; When the latent image area and the non-latent image area are irradiated with visible light, the difference between the order value of the latent image area and the non-latent image area is less than 5; the latent image area and the non-latent image area are irradiated at least In the case where the ultraviolet light of the wavelength region is included, the difference in the order value of the latent image region with respect to the non-latent image region is 5 or more.

According to the above configuration, regarding the latent image region, when the latent image region and the non-latent image region are irradiated with visible light (wavelength region 400 nm to 760 nm), the difference in the degree value of the latent image region with respect to the non-latent image region Become less than 5. Therefore, a latent image region is provided on the surface of the solid preparation, and the latent image region is formed by a latent image ink layer which is difficult to recognize under visible light irradiation. On the other hand, the latent image region is a region composed of a latent image ink layer, and the latent image ink layer absorbs ultraviolet rays in a wavelength range of 200 nm or more and less than 400 nm. In addition, the non-latent image region is a region that reflects ultraviolet rays in the above-mentioned wavelength region and / or absorbs and converts the ultraviolet rays to other ultraviolet regions or visible light regions to emit fluorescence. Furthermore, regarding the latent image region, when the latent image region and the non-latent image region are irradiated with ultraviolet rays, the difference in the degree value of the latent image region with respect to the non-latent image region becomes 5 or more. Therefore, the latent image area can be developed with a good contrast with the latent image formed by the latent image ink layer under the irradiation of ultraviolet rays.

In the above configuration, it is preferable that another non-latent image region where a visible image is formed by absorbing the visible ink layer of the visible light is further provided on the surface. When the visible light is irradiated, the difference between the order values of the other non-latent image regions and the non-latent image regions when the visible light is irradiated is 5 or more.

According to the above configuration, other non-latent image areas are areas where a visible image is formed by the visible ink layer absorbing visible light. When the non-latent image area and other non-latent image areas are irradiated with visible light, other non-latent image areas The difference in the gradation value with respect to the non-latent image area becomes 5 or more. Therefore, a visible image composed of a visible ink layer can be viewed with good contrast under visible light. In contrast, the latent image formed by the latent image ink layer is difficult to recognize under visible light irradiation, but on the other hand, the latent image formed by the latent image ink layer can have good contrast under ultraviolet radiation in the above-mentioned wavelength region. Recognize. Therefore, according to the above structure, information can be recorded on the surface of a solid preparation in the form of a latent image or a visible image according to the content of the information, etc., thereby improving the freedom of the method of recording the information.

Furthermore, in the above configuration, it is preferable that the visible ink layer is a layer that transmits or reflects ultraviolet rays in the wavelength region, and irradiates the non-latent image region and the other non-latent image regions with ultraviolet light including the wavelength region. In this case, the difference between the order values of the other non-latent image areas and the non-latent image areas is less than 5.

According to the above configuration, a visible image that can be viewed under irradiation with visible light can be an image that is difficult to be viewed under irradiation with light including ultraviolet rays. In addition, although the latent image is difficult to see under the irradiation of visible light, on the other hand, the latent image can be seen by being developed under the irradiation of light containing ultraviolet rays. Therefore, by changing the wavelength region of the irradiated light, it is possible to realize the inverse representation of the visible image and the latent image. As a result, even if the area of the printable area on the solid preparation is small, more information can be recorded on the surface of the solid preparation.

In the above configuration, the latent image ink layer preferably contains at least titanium oxide particles and / or zinc oxide particles as a pigment. By containing at least titanium oxide particles and / or zinc oxide particles as pigments in the latent image ink layer, the latent image ink layer can exhibit good light absorption to ultraviolet rays. In addition, titanium oxide and zinc oxide meet the standards of pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations stipulated in the Japanese Pharmacopoeia Law, and therefore have low biological hazards. As a result, latent images can be printed directly on solid preparations such as pharmaceuticals and tablets. Furthermore, compared with the ink layer using a dye, the light resistance can also be improved.

Moreover, in the said structure, it is preferable that the said latent image ink layer has light transmittance or light reflectivity with respect to the said visible light. The latent image ink layer has light transmittance to visible light, which can further reduce the difference between the order values of the latent image area and the non-latent image area when the visible light is irradiated to the latent image area and the non-latent image area. As a result, the visibility under the visible light irradiation of the latent image region can be further reduced. In addition, for example, in a case where the non-latent image area is an area that reflects at least a portion of visible light, the visibility of the latent image ink layer can be reduced by the light reflectivity of the latent image ink layer.

In order to solve the above-mentioned problem, in the method for photographing a latent image printed matter of the solid preparation of the present invention, the solid preparation is provided with a latent image on at least a part of the surface; the solid preparation has at least: a latent image area and is provided with absorption The latent image ink layer of the ultraviolet latent image ink layer having a wavelength range of 200 nm or more and less than 400 nm is formed with the latent image by the latent image ink layer; and the non-latent image region reflects at least the ultraviolet light in the wavelength region and / or Fluorescent light is emitted; when the latent image area and the non-latent image area are irradiated with visible light, the difference between the order value of the latent image area and the non-latent image area is less than 5; When the latent image area is irradiated with ultraviolet light including the wavelength range, the difference between the order value of the latent image area and the non-latent image area is 5 or more; the photography method of the latent image printed matter of the solid preparation includes: developing A step of irradiating the latent image region and the non-latent image region with irradiation light including at least the ultraviolet ray in the wavelength region to make the latent image Development of the latent image in the field; and a photographing step, receiving reflected light reflected by the irradiated light on the non-latent image area and / or fluorescent light generated on the non-latent image area, and developing the developing step. The above-mentioned latent image area and the non-latent image area are photographed.

According to the above configuration, a latent image region is provided on the surface of the solid preparation to be photographed, and the difference between the order values of the latent image region and the non-latent image region under visible light irradiation is not more than 5. Therefore, the latent image region can be formed in a latent image in which it is difficult to recognize the latent image region under visible light. The latent image region is a region that absorbs ultraviolet rays in a wavelength range of 200 nm or more and less than 400 nm. On the other hand, the non-latent image region is a region that reflects and / or emits ultraviolet light in the above-mentioned wavelength region. In addition, the latent image region is configured such that when the latent image region and the non-latent image region are irradiated with ultraviolet light including the above-mentioned wavelength region, a difference in the degree value of the latent image region with respect to the non-latent image region becomes 5 or more. Therefore, in the above configuration, the latent image region and the non-latent image region are irradiated with the irradiation light including at least the ultraviolet rays in the above-mentioned wavelength region, so that the latent image region can be developed with a good contrast (development step). Further, in the above configuration, the reflected light reflected from the non-latent image area and / or the fluorescent light generated from the non-latent image area are received, and the developed latent image area and the non-latent image area are photographed. (Photographing steps). Therefore, for example, in order to prevent the manufacture of fake products, the printed matter in which solid information such as product information is formed in the form of a latent image can be irradiated with ultraviolet rays in the above-mentioned wavelength region, so that the latent image can be easily developed. The identification or inspection of the latent image is performed.

In the above configuration, it is preferable that the developing step is a step of using only ultraviolet rays having a wavelength range of 200 nm or more and less than 400 nm as the irradiation light. The latent image ink layer is a layer that absorbs ultraviolet rays in a wavelength range of 200 nm to less than 400 nm. Therefore, by setting the irradiation light used in the development step to only ultraviolet rays in the wavelength range, the potential can be further increased. The difference in the degree value of the shadow area with respect to the non-latent image area can be developed with better contrast.

In addition, in the above configuration, it is preferable that the wavelength range of the ultraviolet light included in the irradiation light in the developing step and the wavelength range of the reflected light and / or the fluorescent light received in the photographing step are at least Some overlap. Thereby, the amount of light received in the photographing step can be increased, and the latent image area and the non-latent image area can be photographed with good contrast.

In the above configuration, the solid preparation further has other non-latent image regions in which a visible image is formed by the visible ink layer absorbing the visible light, and the non-latent image region and the other non-latent image regions are irradiated with visible light. At that time, the difference between the order values of the other non-latent image areas and the non-latent image areas is 5 or more. The above-mentioned photographing step may be a step of also photographing the other non-latent image areas.

According to the above configuration, a person who has a visible image formed on the surface of the solid preparation by absorbing a visible ink layer to form a visible image can be set as a photographic subject. In addition, when the visible ink layer is, for example, an ink layer that can be recognized even under the irradiation of ultraviolet rays in the above-mentioned wavelength region, other non-latent image regions provided with the visible ink layer are also photographed in the photographing step, thereby Can check the visible ink layer.

Furthermore, in the above configuration, it is preferable that the visible ink layer is a layer that transmits or reflects ultraviolet rays in the wavelength region, and irradiates the non-latent image region and the other non-latent image regions with ultraviolet light including the wavelength region. In this case, the difference between the step values of the other non-latent image regions and the non-latent image regions is less than 5, and the developing step is also irradiating the other non-latent image regions with ultraviolet rays including at least the wavelength region. The step of irradiating light to latentize the visible images of the other non-latent image areas. The photographing step is also a step of photographing other non-latent image areas that are latently imaged in the developing step.

According to the above configuration, by forming a visible ink layer that transmits or reflects ultraviolet rays in the above-mentioned wavelength region, the other non-latent image regions make other non-latent image regions relative to the non-latent image regions under the irradiation of light including the ultraviolet rays. The difference in degrees becomes less than 5. Therefore, other non-latent image regions can be latently imaged in the developing step, and it is difficult to recognize the other non-latent image regions. Thereby, in the photographing step, only the developed latent image in the developing step can be photographed, thereby preventing the identification or inspection of the latent image from being obstructed by visible images.

Moreover, in the said structure, it is preferable to use the said latent image ink layer as a solid preparation which contains at least a titanium oxide particle and / or a zinc oxide particle as a pigment. As a result, the latent image ink layer exhibits good light absorption to ultraviolet light. Therefore, when the latent image area and the non-latent image area are irradiated with ultraviolet light having a wavelength range of at least 200 nm and less than 400 nm, this can be achieved Development in the latent image area under ultraviolet irradiation. In addition, titanium oxide and zinc oxide meet the standards of pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations stipulated in the Japanese Pharmacopoeia Law, and therefore have low biological hazards. As a result, latent images can be printed directly on solid preparations such as pharmaceuticals and tablets. Furthermore, compared with the ink layer using a dye, the light resistance can also be improved.

Moreover, in the said structure, it is preferable that the said latent image ink layer has light transmittance or light reflectivity with respect to visible light. The latent image ink layer has light transmittance to visible light, which can further reduce the difference between the order values of the latent image area and the non-latent image area when the visible light is irradiated to the latent image area and the non-latent image area. As a result, the visibility under the visible light irradiation of the latent image region can be further reduced. In addition, for example, in a case where the non-latent image area is an area that reflects at least a portion of visible light, the visibility of the latent image ink layer can be reduced by the light reflectivity of the latent image ink layer.

In order to solve the above problems, in the edible matter inspection method of the present invention, the edible matter is provided with a latent image on at least a part of the surface; the edible matter inspection method of the present invention is characterized in that the edible matter is at least a part The latent image region has the latent image formed by the latent image ink layer, and the latent image ink layer absorbs ultraviolet rays in a wavelength range of 200 nm to 400 nm; and a non-latent image region through the wavelength region. The ultraviolet light emits fluorescence in the visible light region; the inspection method of the edible material includes a developing step, and irradiates the latent image region and the non-latent image region with ultraviolet light including at least the wavelength region, The fluorescent light is generated in the non-latent image area, and the ultraviolet light is absorbed in the latent image ink layer in the latent image area, thereby developing the latent image in the latent image area; and an inspection step for visually or by The imaging mechanism whose light-receiving wavelength is in the visible light region photographs and inspects the latent image developed in the developing step.

According to the above configuration, a non-latent image region and a latent image region are provided on the surface of the edible object to be inspected, and the non-latent image region is a region where fluorescence is generated in the visible light region when the ultraviolet light is irradiated in the wavelength region. The aforementioned latent image region is a latent image formed by a latent image ink layer that absorbs ultraviolet rays in a wavelength range of 200 nm to 400 nm. Therefore, in the case of visual observation under the irradiation of ultraviolet rays, or when photographing is performed using a photographing mechanism with a light receiving wavelength in the visible light region (400nm to 760nm), fluorescence is generated in the non-latent image region, so it is a region with higher brightness Identified. On the other hand, in the latent image region, since ultraviolet rays are absorbed, fluorescence excitation is not performed. Therefore, no fluorescence is generated in the latent image area, and it is identified as a region having a lower brightness than the non-latent image area. Therefore, if the latent image area and the non-latent image area are irradiated with ultraviolet rays, the latent image of the latent image area can be developed with a good contrast (developing step), and a simple inspection can be realized in a subsequent inspection step. Here, the developing step is to develop the latent image by generating fluorescent light in a visible light region in the non-latent image region. Therefore, the latent image can be visually inspected in the inspection step. Alternatively, it can be performed using an imaging mechanism that receives light in a visible light region. Therefore, it is not necessary to use a special device such as an ultraviolet camera as a photographing mechanism, and a latent image inspection can be easily performed. In addition, for example, when a customer wants to confirm images such as product information printed in the form of a latent image, or when they want to confirm the authenticity of the product, the product can be easily and cheaply identified.

In the above configuration, it is preferable that the developing step is a step of using only ultraviolet rays having a wavelength range of 200 nm or more and less than 400 nm as the irradiation light. The latent image ink layer is a layer that absorbs ultraviolet rays in a wavelength range of 200 nm to 400 nm. Therefore, by setting the irradiation light used in the development step to only ultraviolet rays in the wavelength region, the latent image can be further improved. The contrast of the area with respect to the non-latent image area, so that better development can be achieved.

In the said structure, it is preferable that the latent image ink layer of the said edible contains at least a titanium oxide particle and / or a zinc oxide particle as a pigment. By containing at least titanium oxide particles and / or zinc oxide particles as pigments in the latent image ink layer, the latent image ink layer can exhibit good light absorption to ultraviolet rays. In addition, titanium oxide and zinc oxide meet the standards of pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations stipulated in the Japanese Pharmacopoeia Law, and therefore have low biological hazards. As a result, a solid preparation composed of a tablet such as a pharmaceutical or food can be used as an edible substance, and a solid preparation directly printed with a latent image on the solid preparation can be used as an inspection object. Furthermore, compared with the ink layer using a dye, the light resistance can also be improved.

In the above configuration, it is preferable that the latent image ink layer of the edible material is a coating film made of water-based ink before or after drying. When the latent image ink layer is a coating film made of water-based ink before drying, it can be easily confirmed whether the printing state of the coating film is good or not. For example, in the case of printing using water-based ink by an inkjet method, it is possible to easily check whether there is an error in the spraying position of the droplets of the water-based ink ejected from the inkjet head or a deviation in the printing position. In addition, it is also possible to easily check whether a printing defect occurs due to a nozzle defect of the inkjet head. As a result, a latent image print of an edible which has a higher yield than before can be provided. In addition, in the case where the latent image ink layer is a coating film made of water-based ink after drying, the product information printed in the form of a latent image or the authenticity of the product can be easily confirmed at the time of use.

In the above configuration, it is preferable that the latent image ink layer of the edible material has light transmittance to visible light. The latent image ink layer has light permeability to visible light, which can further reduce the visibility of the latent image under visible light.

In the above configuration, it is preferable that a wavelength of ultraviolet rays included in the irradiation light in the developing step and a wavelength of ultraviolet rays absorbed in the latent image ink layer overlap at least a part.

According to the latent image printed matter of the solid preparation of the present invention, the latent image area formed with the latent image ink layer by the latent image ink layer is configured such that when the latent image area and the non-latent image area are irradiated with visible light, the latent image area is relatively The difference in the gradation value in the non-latent image area becomes less than 5. Therefore, in the latent image print of the present invention, it is difficult to visually recognize (identify) the latent image under visible light irradiation. In addition, the latent image region is a region in which a latent image is formed by absorbing a latent image ink layer in which the wavelength region is 200 nm or more and less than 400 nm. The non-latent image region is an ultraviolet reflection and / or in the wavelength region. Areas that emit fluorescence. In addition, the latent image area is configured such that, when the latent image area and the non-latent image area are irradiated with ultraviolet rays, the difference in the degree value of the latent image area with respect to the non-latent image area becomes 5 or more. Therefore, according to the present invention, a latent image printed matter having a solid preparation having a latent image can be provided, and the latent image can be developed with good contrast by irradiation with ultraviolet rays in the above-mentioned wavelength region.

In addition, according to the photographic method of the latent image printed matter of the solid preparation of the present invention, the latent image is developed by irradiating the latent image area and the non-latent image area of the solid preparation with at least the above-mentioned wavelength range of ultraviolet light, and receiving the developed image The reflected light reflected in the non-latent image area and / or the fluorescent light generated in the non-latent image area are photographed for the developed latent image area and the non-latent image area. Therefore, for example, a printed matter in which a solid preparation is printed with product information and the like in the form of a latent image for the purpose of preventing the manufacture of a fake product, can be easily developed by irradiating ultraviolet rays in the above-mentioned wavelength region and photographed. As a result, according to the present invention, a method for photographing a latent image printed matter of a solid preparation can be provided, and the latent image provided on the solid preparation can be easily identified or inspected.

In addition, according to the edible matter inspection method of the present invention, the edible matter to be inspected includes a latent image printed matter of a latent image region and a non-latent image region, and the aforementioned latent image region absorbs a wavelength of 200 nm or more and less than 400 nm. A latent image is formed by the ultraviolet ink layer in the region, and the non-latent image region generates fluorescence in a visible light region by irradiating the ultraviolet light. For such a latent image print, in the present invention, ultraviolet rays are irradiated in the developing step, thereby generating fluorescent light in a visible light region in a non-latent image region. Thereby, the non-latent image region is recognized as a region with higher brightness. On the other hand, since the latent image region absorbs ultraviolet rays and no fluorescence is generated, it is recognized as a region having lower brightness than the non-latent image region. As a result, the latent image in the latent image area is developed with a good contrast. This makes it possible to easily perform latent image inspection and the like without using a special imaging mechanism such as an ultraviolet camera. In addition, for example, in the case of a demander and the like who want to confirm images of product information printed in the form of a latent image, or when they want to confirm the authenticity of a product, the latent image can be easily identified at low cost.

10, 20‧‧‧ solid preparation

11‧‧‧ Latent Shadow Ink Layer

12‧‧‧ visible ink layer

21‧‧‧light irradiation mechanism

22‧‧‧Photographic Agency

23‧‧‧The first optical filter

24‧‧‧Second Optical Filter

A‧‧‧ Sub-Image Area

B, D‧‧‧ non-latent image area

C‧‧‧Other non-latent image areas

FIG. 1 is an explanatory view schematically showing a latent image printed matter of a solid preparation according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an outline of a photographing device used in a method for photographing a latent image printed matter of a solid preparation.

FIG. 3 is an explanatory view schematically showing a latent image printed matter of a solid preparation according to another embodiment of the present invention.

FIG. 4 is an explanatory view schematically showing a latent image printed matter of a solid preparation according to still another embodiment of the present invention.

FIG. 5 is a graph showing an absorption spectrum in a range of 190 nm to 500 nm of the water-based ink composition used in each of Examples and Comparative Examples.

FIG. 6 is a graph showing an absorption spectrum in the range of 260 nm to 800 nm of the water-based ink composition used in each Example.

(Embodiment 1)

<Latent image print of solid preparation>

Hereinafter, a latent image printed matter (hereinafter, referred to as a "latent image printed matter") of the solid preparation of the first embodiment will be described. FIG. 1 is an explanatory view schematically showing a latent image printed matter of the solid preparation of the present embodiment.

As shown in FIG. 1, the latent image print of the present embodiment is provided with a latent image ink layer 11 on at least a part of the surface of the solid preparation 10. The latent image ink layer 11 forms a printed image as a latent image. In addition, the latent image printed matter of this embodiment has at least: a latent image area A where the latent image ink layer 11 forms a latent image; and a non-latent image area B where no latent image is formed.

In this specification, the meaning of "solid preparation" includes food preparations and pharmaceutical preparations. Examples of the solid preparation include OD tablets (oral dispersing tablets), plain tablets, and FC tablets (film coating tablets). Film-coated tablets), sugar-coated tablets and other lozenges or capsules. The solid preparation 10 may be used for medicine or food. Examples of lozenges for food use include health foods such as lozenges and supplements. In the solid preparation 10, the lozenge is solid at normal temperature, for example, it is preferably a lozenge manufactured by compressing and / or forming a lozenge material containing an active ingredient into a certain shape. The shape of the tablet is not particularly limited, and any shape can be adopted. In addition, the lozenge may be a lozenge for pharmaceutical use or a lozenge for food use. Examples of lozenges for food use include health foods such as lozenges and supplements.

In addition, in this specification, a "latent image" means an image that is difficult to recognize under an environment irradiated with visible light (wavelength region of 400 nm to 760 nm) and developed under specific conditions. Further, the “latent image print” in this specification means a printed product in which a latent image is printed on the solid preparation 10 as a printed image. Here, the image printed in the form of a latent image can be printed by, for example, an inkjet method using an inkjet aqueous ink described later. In addition, the so-called inkjet printing means a method in which an inkjet aqueous ink is ejected from a fine inkjet head in the form of droplets, and the droplets are fixed to the solid preparation 10 to form an image.

[Latent image area]

The latent image region A is a region in which a latent image is formed by the latent image ink layer 11. The latent image ink layer 11 absorbs ultraviolet rays in a wavelength range of 200 nm or more and less than 400 nm. The above-mentioned wavelength region is more preferably in a range of 260 nm to 380 nm, and particularly preferably in a range of 280 nm to 360 nm. The latent image ink layer 11 is preferably light-transmissive to visible light. Furthermore, the latent image ink layer 11 may have light reflectivity with respect to visible light. In this case, for example, as will be described later, if the non-latent image area B is an area that reflects at least a portion of visible light, the latent image can be preferably formed by the latent image ink layer 11. In addition, "light transmittance" in this specification means the property which transmits at least a part of incident visible light etc. In addition, the meaning of light transmittance includes a case where it is colored, in addition to a case where the latent image ink layer 11 is colorless. Furthermore, "light reflectivity" in this specification means a property which reflects at least a part of incident visible light and the like.

In the latent image region A, a visible ink layer or coating layer formed on an image that can be viewed under visible light may also be provided. By making the latent image ink layer 11 transparent to visible light, the visibility of the visible ink layer can be ensured even when the visible ink layer is disposed below the latent image ink layer 11. The details of the visible ink layer will be described in the second embodiment. Examples of the coating layer include an overcoat layer and an undercoat layer that cover the latent image ink layer 11 for protection.

The latent image ink layer 11 is preferably a layer composed of a dry film of an inkjet water-based ink (the details will be described later). The dry film can be formed by directly printing on the surface of the solid preparation 10 using, for example, an inkjet aqueous ink using an inkjet method or the like. In addition, it is preferable that the latent image ink layer 11 contains at least a component (hereinafter, sometimes referred to as an “ultraviolet absorbing component”) having a light absorptivity to ultraviolet rays in the above-mentioned wavelength range. Furthermore, it is preferable that the ultraviolet absorbing component is uniformly contained in the latent image ink layer 11. Examples of the ultraviolet absorbing component include titanium oxide (TiO ₂ ) particles and zinc oxide particles as pigments. The thickness of the latent image ink layer 11 is not particularly limited, and can be appropriately set as needed.

[Non-latent image area]

The non-latent image region B is a region that reflects the ultraviolet light when it is irradiated with at least ultraviolet light (hereinafter, referred to as "irradiation light") in the above-mentioned wavelength region. Alternatively, the non-latent image region B is a region that absorbs ultraviolet rays as excitation light and emits fluorescent light. The fluorescent light generated in the non-latent image region B may also include ultraviolet rays in the above-mentioned wavelength region or light in the visible region. In addition, it may include a case where ultraviolet rays having a wavelength different from that of the irradiated ultraviolet rays are generated as fluorescent light. Furthermore, the non-latent image area B may be an area that simultaneously reflects ultraviolet rays and generates fluorescence.

Here, "fluorescence" in this specification means that when ultraviolet rays (excitation light) are irradiated in a wavelength range of 200 nm to 400 nm, the ultraviolet rays are absorbed and converted into wavelengths, so that they are emitted in the form of fluorescence. Different wavelengths of ultraviolet or visible light (380nm to 760nm). In addition, its significance also includes the fluorescence of components with short decay time in the residual light that is still emitted after the irradiation of ultraviolet rays. In addition, the decay time means the time required for the transition from the start of the emission of the above-mentioned components to the return to the ground state (the disappearance of fluorescence).

In order for the non-latent image region B to have light reflectivity for ultraviolet rays in a wavelength range of 200 nm to 400 nm, for example, it is preferable that the solid preparation 10 contains a component for reflecting ultraviolet rays in the wavelength region. In this regard, for example, a commercially available white tablet or capsule has the property of reflecting ultraviolet rays in the above-mentioned wavelength region, so that a non-latent image region B can be formed. Furthermore, even when the solid preparation 10 itself contains ultraviolet absorbing components such as titanium oxide or zinc oxide, an ultraviolet reflecting layer containing a component that exhibits light reflectivity to ultraviolet rays in the above-mentioned wavelength region is provided on the surface of the solid preparation 10, Non-latent image area B can be formed. Alternatively, by controlling the particle size of the titanium oxide particles or zinc oxide particles contained in the latent image ink layer 11, the absorption wavelength of ultraviolet light by the latent image ink layer 11 and the titanium oxide or zinc oxide contained in the solid preparation 10 are controlled. Non-latent image regions B can also be formed with different absorption wavelengths.

In addition, in order to provide the non-latent image region B with the property of exhibiting fluorescence when irradiated with ultraviolet rays in the above-mentioned wavelength region, for example, it is preferable that the solid preparation 10 contains ultraviolet rays that absorb the wavelength region as excitation light to be emitted. Fluorescent component of fluorescence. Such a fluorescent component is not particularly limited as long as it is an edible component, and specific examples thereof include riboflavin and the like. These fluorescent components can be used individually by 1 type or in mixture of 2 or more types. Furthermore, even when the solid preparation 10 itself contains an ultraviolet absorbing component such as titanium oxide or zinc oxide, it can be formed by providing a fluorescent layer containing a fluorescent component on the surface of the solid preparation 10 with respect to the ultraviolet rays in the above-mentioned wavelength region. Non-latent image area B. Here, "fluorescence" in this specification means the property of emitting fluorescence. In addition, in this specification, "edible" means that it is comprised only of the substance confirmed as oral administration as a medicinal product or a medicinal additive, and / or the substance confirmed as a food or a food additive.

In addition, the non-latent image region B may include a case where at least a part of the visible light is reflected or absorbed under the irradiation of visible light. A coating or the like may be provided in the non-latent image region B.

[Difference between order values of latent image area and non-latent image area]

In the case where the latent image area A and the non-latent image area B are simultaneously irradiated with visible light, the difference between the order values of the latent image area A and the non-latent image area B is preferably less than 5. By setting the difference between the gradation values to less than 5, it is possible to make it difficult to recognize (or identify) the latent image (latent image ink layer 11) under visible light irradiation.

In this specification, the so-called "gradation value" refers to the value of the lightness or darkness of a photographed image, which means that the image data is converted into grayscale by a simple average method, a weighted average method, or a median method. scale) An 8-bit scale value (a value of 256 stages from 0 to 255). In the present specification, the "difference in gradation value" means a value obtained by subtracting the average value of the gradation value of the non-latent image area B from the average value of the gradation value of the latent image area A. Furthermore, the average value of the gradation value means the average value of the gradation values of a plurality of pixels in the image data of the latent image area A or the non-latent image area B.

When the latent image area A and the non-latent image area B are simultaneously irradiated with irradiation light containing at least ultraviolet rays, the difference in the degree value of the latent image area A with respect to the non-latent image area B is 5 or more, preferably 15 or more, More preferably, it is 30 or more. By setting the difference in the gradation value to 5 or more, the latent image region A can be developed and observed under ultraviolet irradiation.

The gradation values in the latent image area A and the non-latent image area B when the irradiation light is irradiated can be controlled by, for example, adjusting the light intensity of the irradiation light. Specifically, by appropriately controlling the light intensity of the irradiated light, the difference between the gradation values of the latent image area A and the non-latent image area B can be maximized, thereby achieving clearer photography. For example, when the light intensity of the light source irradiating the light is too weak, the order values of the latent image area A and the non-latent image area B both become small and the difference between the order values can be increased. Light intensity increases the difference in gradation values. In addition, when the light intensity of the light source is too large and the photography is overexposed, the order values of the latent image area A and the non-latent image area B both become large and the difference between the order values can be reduced. The intensity increases the difference in the order value. In addition, the difference in the gradation value of the latent image area A with respect to the non-latent image area B can be controlled by an optimal combination with the wavelength of at least ultraviolet rays included in the irradiated light, in addition to the light intensity of the irradiated light. Alternatively, by adjusting the concentration of the ultraviolet absorbing component contained in the latent image ink layer 11, the ultraviolet absorbing ability in the latent image area A can be increased or decreased, thereby controlling the latent image area A relative to the non-latent image area B. The difference in the degree value.

[Latent image water-based ink]

As a constituent material of the latent image ink layer 11 forming the latent image region A, in this embodiment, it is preferable to use an edible latent image water-based ink. The latent image water-based ink includes a latent image water-based ink composition. The latent image water-based ink composition contains at least a pigment composition (the details will be described later) and water as a main solvent. In addition, the latent image aqueous ink composition according to this embodiment is edible and is suitable for inkjet recording. Furthermore, since the latent image water-based ink composition uses a pigment as a colored material, it is superior in color development properties, light resistance, and water resistance compared to an ink composition using a dye.

The content of the pigment composition is preferably in a range of 2% to 40% by mass, and more preferably in a range of 5% to 30% by mass, based on the total mass of the latent image water-based ink composition. By setting the content of the pigment composition to 2% by mass or more, the coloring power can be improved. On the other hand, when the content of the pigment composition is 40% by mass or less, dispersibility can be improved.

The water-based ink composition of the latent image of this embodiment contains water (water as a main solvent). As the water, pure water such as ion-exchanged water, ultra-filtered water, reverse osmosis water, or distilled water, or water from which ionic impurities have been removed, such as ultra-pure water, is preferably used. In particular, water subjected to a sterilization treatment by irradiating ultraviolet rays or adding hydrogen peroxide is preferable because it can prevent the generation of mold or bacteria for a long period of time. The content of water is not particularly limited, and can be appropriately set as needed.

In the water-based ink composition of the latent image of this embodiment, other additives may be blended. However, when it is used as an inkjet ink for tablets such as pharmaceuticals, it is preferably an additive that complies with standards such as the Japanese Pharmaceutical Affairs Law.

Examples of the additives include a surface tension adjuster, a wetting agent (anti-drying agent), an anti-fading agent, an emulsifying stabilizer, a penetration enhancer, an ultraviolet absorber, a preservative, a mold inhibitor, a pH adjuster, and a viscosity adjuster. , Well-known additives such as dispersion stabilizers, rust inhibitors, and chelating agents. The content of these various additives is not particularly limited, and can be appropriately set as needed.

The surface tension adjusting agent is not particularly limited as long as it is a compound that complies with standards such as the Japanese Pharmaceutical Affairs Law. Specific examples include glycerin fatty acid esters and polyglycerol fatty acid esters. Examples of the glycerin fatty acid ester include deca glyceryl caprylate and deca glyceryl laurate.

The addition amount of the surface tension adjusting agent is preferably such that the surface tension of the latent image water-based ink composition can be adjusted to a range of 25 mN / m to 40 mN / m, and more preferably can be adjusted to a range of 27 mN / m to 36 mN / m. When the addition amount is within the above range, it is possible to ensure the discharge stability and the like during printing by the inkjet method.

The wetting agent is not particularly limited as long as it is a compound that complies with standards such as the Japanese Pharmaceutical Affairs Law. Specific examples include propylene glycol, glycerin, and the like.

The added amount of the humectant is preferably 3% by mass to 50% by mass, and more preferably 10% by mass to 40% by mass relative to the total mass of the latent image water-based ink composition.

Regarding the viscosity of the water-based ink composition of the latent image according to this embodiment, if the discharge stability from the inkjet nozzle is considered, it is preferably 2mPa‧s to 7mPa‧s, and more preferably 3mPa‧ when spraying from the inkjet nozzle. s to 5mPa‧s. By setting the viscosity of the water-based ink composition of the latent image to be within the above-mentioned numerical range, clogging of the inkjet nozzle can be suppressed, and good ejection stability can be maintained, and reduction in flying properties can be suppressed. The viscosity of the latent image water-based ink composition is obtained, for example, by using a viscometer (trade name: VISCOMATE MODEL VM-10A, manufactured by Sekonic (Stock Corporation)) at a measurement temperature of 25 ° C. The measurement was performed under the conditions.

The latent image water-based ink composition of this embodiment can be produced by mixing the aforementioned components by an appropriate method. That is, for example, an additive or the like is separately added to the dispersion liquid of the pigment composition, and then diluted with water. After that, the mixture is sufficiently stirred, and if necessary, filtration is performed to remove coarse particles and foreign matter that may cause clogging. Thereby, the latent image water-based ink composition of this embodiment can be obtained.

The method of mixing the materials is not particularly limited. For example, materials are sequentially added to a container provided with a stirring device such as a mechanical stirrer or a magnetic stirrer, and the mixture is stirred and mixed. The filtration method is not particularly limited, and for example, centrifugal filtration or filter filtration can be used.

The latent image water-based ink composition of this embodiment is composed of ingredients that conform to standards such as the Japanese Pharmaceutical Affairs Law, so it is edible and can be directly printed on the surface of tablets such as pharmaceuticals or supplements. In addition, for tablets with poor surface smoothness such as plain tablets or OD tablets, non-contact printing using inkjet methods can also be performed. Furthermore, since the latent image water-based ink composition is also excellent in light resistance, even if it is directly printed on the surface of a tablet such as a pharmaceutical or a supplement, the occurrence of bleeding can be prevented.

[Pigment composition]

The pigment composition contained in the latent image water-based ink composition contains at least a pigment (ultraviolet absorbing component) composed of titanium oxide (TiO ₂ ) particles and / or zinc oxide particles, and sodium polyacrylate as a pigment dispersant. Composition of pigment dispersion. First, a case where titanium oxide particles are used as a pigment having a function as an ultraviolet absorbing component will be described.

The pigment composed of titanium oxide particles is a white pigment, which has a smaller specific gravity and a larger refractive index than other known white pigments. In addition, the chemical and physical properties of titanium oxide pigments are also stable. Therefore, a pigment composed of titanium oxide particles is excellent in concealability or colorability, and is also excellent in durability against acids, alkalis, and other environments. In addition, the pigment composition of this embodiment may contain a well-known pigment other than a pigment.

In this embodiment, as the titanium oxide particles, an anatase (anatase), rutile (orthorhombic), or brookite (orthorhombic) crystal structure can be used. Any of titanium oxide particles. However, from the viewpoint of improving the concealment of a printed image, titanium oxide having a rutile crystal structure is preferred. This prevents the printed image from being visually observed from the printed (formed) surface of the printed image. In the present invention, the titanium oxide particles mean crystalline titanium oxide particles unless otherwise specified.

The surface of the titanium oxide particles is preferably hydrophilic. Thereby, the average dispersed particle diameter of the dispersed titanium oxide particles can be made close to the average primary particle diameter of the titanium oxide particles (the details will be described later). On the surface of the titanium oxide particles, a hydroxyl group usually exists, whereby the surface of the titanium oxide particles exhibits hydrophilicity. In the present invention, the term "hydrophilic" refers to the presence of a functional group having an affinity for water on the surface of the titanium oxide particles.

In addition, in the present invention, from the viewpoint of improving or maintaining the hydrophilicity of the surface of the titanium oxide particles, a hydrophilizing treatment may be performed. When hydrophilizing the surface of a titanium oxide particle, the surface treating agent of an inorganic compound and / or an organic compound can be used, for example.

The surface treatment agent for the inorganic compound is not particularly limited, and examples thereof include aluminum hydroxide, aluminum oxide, zirconia, silicon oxide, and cerium oxide. In addition, the surface treatment agent for the organic compound is not particularly limited, and examples thereof include dimethyl polysiloxane, methyl hydrogen polysiloxane, and (dimethyl polysiloxane / methyl polysiloxane) copolymerization. Compounds, methylphenyl silicone, amine-modified silicone, hydrogenated dimethylpolysiloxane, triethoxysilylethylpolydimethylsiloxyethyldimethylsiloxane, triethyl Silicone oils such as oxysilylethyl polydimethylsilyloxyethylhexyldimethylpolysiloxane; higher fatty acids such as stearic acid and lauric acid; trimethylolethane, pentaerythritol, and tripropanol ethyl Polyols such as alkane, di-trimethylolpropane, trimethylolpropane ethoxylate; alkanolamines such as triethanolamine, tripropanolamine, or derivatives thereof such as hydrochloride or organic acid salt; octyl Alkyl silanes such as silanes, decyl silanes, perfluorooctyl silanes, alkyl titanates, alkyl aluminates, polyolefins, polyesters, lauryl lysines, etc. Organometallic compounds such as aluminum-based coupling agents and zirconium-based coupling agents. The surface treatment may be performed using at least one compound selected from the organic compounds. Alternatively, an inorganic compound and an organic compound may be combined to perform a hydrophilization treatment.

Commercially available products can be used as the titanium oxide particles. Examples of such commercially available products include STR-100N (trade name, manufactured by Nissho Chemical Co., Ltd., rutile), TTO-51A ( Trade name, Nissho Ishihara Industry (stock company), rutile type), TTO-55A (trade name, Nissho Ishihara Industry (stock company), rutile type), TTO-55A (trade name, Nissho Ishihara industry ( Co., Ltd.), rutile type), TTO-80A (trade name, Nissho Ishihara Industries (stock company), rutile type), MPT-140 (trade name, Nissho Ishihara industry (stock company), rutile type) , MPT-141 (trade name, Nissho Ishihara Industries (stock company), rutile type), MKR-1 (trade name, Nissho chemical industry (stock company), rutile type), KA-10 (trade name , Nissho Titanium Industry (stock company), anatase type), etc.

Next, a case where zinc oxide particles are used as a pigment having a function as an ultraviolet absorbing component will be described. The pigment composed of zinc oxide particles is a white pigment, and is an inorganic pigment having ultraviolet shielding properties.

The surface of the zinc oxide particles may be hydrophilized. However, the zinc oxide particles are preferably zinc oxide particles whose surface has not been hydrophilized with silicon dioxide hydrate (aqueous silicon oxide). That is, zinc oxide particles that have been hydrophilized by forming a film composed of silica hydrate (aqueous silica) on the surface are used together with sodium polyacrylate described later as a pigment dispersant. In such a case, the average dispersion particle diameter of the pigment composed of the zinc oxide particles may increase, and the storage stability may decrease. By using zinc oxide particles whose zinc oxide particles have not been hydrophilized with a silica hydrate surface as zinc oxide particles, the average dispersed particle diameter of the dispersed zinc oxide particles can be close to that of the zinc oxide particles. Average primary particle size. In the present invention, unless otherwise specified, zinc oxide particles mean crystalline zinc oxide particles. As the zinc oxide particles, zinc oxide particles that have been hydrophilized by coating the surface with a compound other than a hydrate of silicon dioxide can be used.

Commercial products can also be used as the zinc oxide particles. Examples of such commercial products include FINEX-50 (trade name, manufactured by Nissho Chemical Industry Co., Ltd.), and FINEX-30 (trade name, Japan Shoji Chemical Industry Co., Ltd.), FINEX-25 (trade name, manufactured by Nisho Chemical Industry Co., Ltd.), etc.

Regarding pigments of titanium oxide particles and / or zinc oxide particles (hereinafter sometimes referred to as "titanium oxide particles"), the pigment composition of this embodiment is used for printing on the surface of tablets such as pharmaceuticals or supplements. In this case, a pigment that meets the standards of the pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations (hereinafter referred to as the "Japanese Pharmaceutical Affairs Law and other standards") prescribed in the Japanese Pharmaceutical Affairs Law is preferred.

The average primary particle diameter (volume average particle diameter) of titanium oxide particles and the like is preferably 20 nm to 400 nm, more preferably 30 nm to 200 nm, and even more preferably 40 nm to 100 nm. By setting the average primary particle diameter to be 20 nm or more, it is possible to suppress a decrease in light resistance of a printed image, and to increase the concentration of a pigment, thereby improving transparency. In addition, sufficient concealment can be ensured. On the other hand, by setting the average primary particle diameter to 400 nm or less, it is possible to achieve high colorization, and it is possible to prevent sedimentation of titanium oxide particles and the like and clogging of nozzles. In addition, when pigment particles with a large average primary particle size are selected, the pigment particles are sufficiently pulverized in order to achieve dispersion of the pigments at a level of the average dispersion particle size required for printing by the inkjet method. The step time becomes longer. However, as described above, by setting the average primary particle diameter to 400 nm or less, the prolongation of the step time can also be suppressed.

Moreover, in the present invention, the so-called "average primary particle size" means the average particle size of primary particles. The so-called primary particles generally refer to the smallest particles constituting a powder, and the meaning includes single crystals or agglomeration of microcrystals close to single crystals. And formed particles.

The average primary particle diameter is an arithmetic average particle diameter determined by observing titanium oxide particles and the like with an electron microscope. Although titanium oxide particles and the like having a monodispersed particle size distribution are used in this embodiment, the present invention is not limited thereto, and titanium oxide particles having a polydispersed particle size distribution may be used. In addition, a pigment having a monodispersed particle size distribution may be used by mixing two or more kinds.

The shape of the titanium oxide particles and the like is not particularly limited, and titanium oxide particles of any shape such as a spherical shape, a rod shape, a needle shape, a spindle shape, and a plate shape can be used. In this embodiment, titanium oxide particles and the like of the same shape may be used, and titanium oxide particles and the like of two or more different shapes may be mixed and used. In addition, the average primary particle diameter in the case of rod-shaped, needle-shaped, and spindle-shaped particles is defined by a multiplied average value of the length (or height) of the major axis and the length (or width) of the minor axis.

The content of the pigment directly affects the image density, and it also affects the storability, viscosity, and pH of the latent image water-based ink composition. Therefore, it may be appropriately set in consideration of these aspects. In general, the content of the pigment is preferably within a range of 2% to 20% by mass, and more preferably within a range of 5% to 15% by mass relative to the total mass of the pigment composition. By setting the content of the pigment composed of titanium oxide particles and the like to 2% by mass or more, it is possible to suppress a decrease in image density. On the other hand, by setting the content of the pigment composed of titanium oxide particles and the like to 20% by mass or less, it is possible to prevent a decrease in glossiness, a clogging of a nozzle, and a decrease in ejection stability.

Sodium polyacrylate functions as a pigment dispersant for the pigment of this embodiment. By blending sodium polyacrylate, the dispersibility of a pigment can be improved. In addition, by using sodium polyacrylate, the generation of air bubbles in the pigment composition and the water-based ink composition of the latent image can be suppressed. As a result, the addition of a defoamer can be omitted. Furthermore, when the latent image aqueous ink composition is ejected from the inkjet head, the air bubbles are not present in the latent image aqueous ink composition, so it is possible to suppress nozzle escape or ejection failure, and open time ( open time). In addition, sodium polyacrylate meets the standards prescribed by the Japan Pharmaceutical Affairs Law and the like. Therefore, sodium polyacrylate can be preferably used for the printing of tablets such as pharmaceuticals or foods.

The mass average molecular weight of sodium polyacrylate is 10,000 or less, preferably 1500 to 10,000, and more preferably 2,000 to 8000. By setting the mass average molecular weight of sodium polyacrylate to 10,000 or less, the molecular chain of sodium polyacrylate adsorbed on the surface of titanium oxide particles or the like is prevented from becoming too long. As a result, it is possible to reduce the cross-linking and aggregation of pigments composed of titanium oxide particles and the like. In addition, by setting the mass average molecular weight of sodium polyacrylate to 1500 or more, the sodium polyacrylate adsorbed on the surface of titanium oxide particles and the like can sufficiently exhibit the repulsive force due to steric hindrance and the like. As a result, re-agglomeration of titanium oxide particles and the like can be suppressed. The mass average molecular weight of sodium polyacrylate is, for example, a value obtained by a measurement method described in Examples described later.

The content ratio of the pigment and sodium polyacrylate in this embodiment is preferably 1: 0.05 to 1: 1.5 on a mass basis, and more preferably 1: 0.1 to 1: 1. By setting the content ratio to 1: 0.05 or more, it is possible to prevent a reduction in dispersibility of pigments such as titanium oxide particles. On the other hand, by setting the content ratio to 1: 1.5 or less, for example, in the case of a water-based ink composition for latent images, it is possible to prevent a decrease in ejection stability due to adhesion to the nozzle plate.

In addition, when sodium polyacrylate is added to a dispersion medium described later, for example, it is relatively less likely to generate bubbles than other conventional pigment dispersants. Therefore, in the pigment composition of this embodiment, the addition of an antifoaming agent can be omitted.

The pigment composition of this embodiment contains a dispersion medium for dispersing pigments of titanium oxide particles and / or zinc oxide particles. Examples of the dispersion medium include water, and more specifically, pure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, and distilled water, or water from which ionic impurities have been removed, such as ultrapure water. In particular, water subjected to a sterilization treatment by irradiating ultraviolet rays or adding hydrogen peroxide is preferable because it can prevent the generation of mold or bacteria for a long period of time. The content of the dispersion medium is not particularly limited, and can be appropriately set as required.

In addition, as the dispersion medium, a mixed solution of water and a water-soluble organic solvent may also be used. The water-soluble organic solvent is not particularly limited as long as it is a solvent that complies with standards such as the Japanese Pharmaceutical Affairs Law. Specific examples include ethanol, n-butanol, isobutanol, n-propanol, isopropanol, acetone, propylene glycol, polyethylene glycol, and glycerol. These can be used individually by 1 type or in mixture of 2 or more types. Furthermore, when the water-soluble organic solvent is used as a dispersion medium, the compounding amount is not particularly limited, and can be appropriately set as necessary.

The average dispersed particle diameter D50 of the titanium oxide particles and the like in a dispersed state is preferably in a range of 20 nm to 500 nm, and more preferably in a range of 40 nm to 100 nm. In addition, the dispersed particle diameter D99 of the pigment (a particle diameter of 99% based on the cumulative particle size in the volume cumulative particle size distribution) is preferably 1000 nm or less, and more preferably 500 nm or less. By setting D50 to 20 nm or more, deterioration in storage stability, light resistance, and ejection stability can be prevented, and reduction in print density can be prevented. On the other hand, when D50 is set to 500 nm or less or D99 is set to 1000 nm or less, separation, sedimentation, and aggregation of pigments can be prevented, thereby maintaining preservation stability. The average dispersed particle diameters D50 and D99 of the pigments are values measured by a dynamic light scattering method using Microtrac UPA-EX150 (trade name, manufactured by Nissho Nikkiso Co., Ltd.).

The average primary particle diameter of the titanium oxide particles and the like and the average dispersed particle diameter D50 of the titanium oxide particles and the like dispersed in the dispersion medium are preferably within a range of 1: 0.3 to 1: 3. In this embodiment, by using a sodium polyacrylate having a mass average molecular weight of 10,000 or less as a pigment dispersant for pigments such as titanium oxide particles, the average dispersed particle diameter of the titanium oxide particles and the like can be made the same as that of the titanium oxide particles. The primary particle size is about the same level. As a result, for example, when titanium oxide particles having a small average primary particle diameter are used, a pigment composition having a small average dispersed particle diameter D50 can be obtained to prevent separation, sedimentation, and aggregation of the pigment, thereby maintaining preservation stability. The ratio of the average primary particle diameter of the titanium oxide particles and the like to the average dispersed particle diameter D50 of the titanium oxide particles and the like is more preferably 1: 0.5 to 1: 2.5, and even more preferably 1: 0.8 to 1: 2.

In the method for producing a pigment composition according to this embodiment, the mixing method or the order of adding a pigment composed of titanium oxide particles and the like, sodium polyacrylate, a dispersion medium, and other additives formulated as required are not particularly limited. For example, pigments such as titanium oxide particles, sodium polyacrylate, and water as a dispersion medium may be mixed at one time, and the mixed solution may be subjected to a dispersion treatment using a general disperser.

However, in this embodiment, by using sodium polyacrylate as a pigment dispersant, it is possible to suppress the generation of bubbles in the pigment composition and the water-based ink composition of the latent image containing the pigment composition. Therefore, a defoaming step for reducing or disappearing the bubbles can be omitted, and an improvement in manufacturing efficiency can be achieved. In addition, since the content of the defoaming agent can be omitted, it is easier to manufacture a pigment composition and a latent image water-based ink composition that meet the standards of the Japanese Pharmaceutical Affairs Law.

The dispersion time in the dispersion treatment is not particularly limited, and can be appropriately set as required. The dispersing machine used for dispersing the pigment is not particularly limited as long as it is a dispersing machine generally used. Specific examples thereof include a ball mill, a roll mill, a sand mill, a bead mill, a paint shaker, a nanonomizer, and the like.

In addition, the pigment composition of the present embodiment includes the form of a pigment dispersion liquid for preparing the latent image water-based ink composition in addition to the form of the latent image water-based ink composition as a final product.

The content of the pigment directly affects the image density, and it also affects the storability, viscosity, and pH of the water-based ink composition of the latent image. Therefore, it may be appropriately set in consideration of these aspects. In general, the content of the pigment is preferably within a range of 2% to 20% by mass, and more preferably within a range of 5% to 15% by mass relative to the total mass of the pigment composition. By setting the content of the pigment composed of titanium oxide particles and / or zinc oxide particles to 2% by mass or more, a reduction in image density can be suppressed. On the other hand, by setting the content of the pigment composed of titanium oxide particles and / or zinc oxide particles to 20% by mass or less, it is possible to prevent a decrease in glossiness, a clogging of a nozzle, and a decrease in ejection stability.

<Printing method of latent image printed matter of solid preparation>

The method for printing a latent image printed matter of the solid preparation of this embodiment includes at least a latent image printing step, and the latent image printing step is to print a latent image on the surface of the solid preparation.

As a method of printing a latent image (latent image ink layer 11) on the surface of the solid preparation 10, for example, an inkjet recording method using a latent image water-based ink composed of a latent image water-based ink composition is mentioned. As described above, the latent image water-based ink composition of this embodiment is excellent in light resistance and does not bleed out, so it can be printed as a latent image capable of developing the product information of the solid preparation 10 and the like.

The inkjet recording method on the surface of the tablet is not particularly limited. Specifically, it can be performed, for example, by spraying a latent image water-based ink composition from a fine nozzle as a droplet, and making this droplet adhere to the surface of a tablet. The ejection method is not particularly limited. For example, continuous ejection type (charge control type, spray type, etc.), on-demand type (piezo method, thermal method, electrostatic suction) can be used. Methods, etc.) and other well-known methods.

In addition, the latent image printing step may include a drying step of drying a coating film (coated film) composed of droplets of the latent image water-based ink formed on the surface of the solid preparation 10. The drying method is not particularly limited, and in addition to hot air drying, natural drying may be performed. In addition, the drying conditions such as the drying time and the drying temperature are not particularly limited, and can be appropriately set depending on the ejection amount of droplets, the type of the water-based ink composition of the latent image, and the like.

<Photographing method of latent image printed matter of solid preparation>

Next, a photographing method of a latent image printed matter of the solid preparation of the present embodiment will be described below.

The photographing method of this embodiment includes: a developing step to develop a latent image; and a photographing step to photograph the developed latent image in the developing step.

The development step can be performed by irradiating the latent image region A and the non-latent image region B with irradiation light including at least ultraviolet rays. The latent image ink layer 11 of the latent image area A absorbs ultraviolet rays by the irradiation of the irradiation light. On the other hand, in the non-latent image region B, ultraviolet rays are reflected and / or fluorescent light is emitted. Thereby, the difference of the order value of the latent image area A with respect to the non-latent image area B becomes 5 or more, and the latent image formed by the latent image ink layer 11 can be developed.

The wavelength range of the ultraviolet rays is in a range of 200 nm or more and less than 400 nm, and can be appropriately set according to the type of the ultraviolet absorption component contained in the latent image ink layer 11. In addition, the light intensity (μW / cm ² ) when the irradiated light is emitted can be appropriately set according to the type of the ultraviolet absorbing component, the content in the latent image ink layer 11, the degree of ultraviolet light absorption, and the like. For example, in the case where titanium oxide or zinc oxide is used as an ultraviolet absorbing component, the light intensity is in the range of 4000 μW / cm ² to 35000 μW / cm ² , more preferably 5000 μW / cm ² to 30,000 μW / cm ² , and most preferably 10000 μW / cm ² to 20000 μW / cm ² . Furthermore, the irradiation angle of the solid preparation 10 by the irradiation light is not particularly limited, and can be appropriately set. In addition, the "irradiation angle" means the angle which the irradiation direction of the irradiation light which irradiates the solid preparation 10 and the horizontal plane on which the solid preparation 10 is mounted.

The photographing step can be performed by receiving reflected light reflected from the non-latent image area B and / or fluorescent light generated from the non-latent image area B (hereinafter, referred to as "reflected light"). Etc. ", and photographed the developed latent image area and non-latent image area in the developing step. The light receiving conditions are preferably set so that the maximum sensitivity is displayed in the wavelength region of the irradiated light. Specifically, it is preferable to set the light receiving conditions so that at least a part of the wavelength region of the receivable light coincides with the wavelength region of the irradiated light, and it is more preferable to set the wavelength region of the receivable light to less than 400 nm. Thereby, the amount of received light can be increased, and the latent image area A and the non-latent image area B can be photographed with good contrast. When the light receiving sensitivity is low or there is no light receiving sensitivity in a wavelength region such as reflected light, it may be difficult to photograph the developed latent image region A and the non-latent image region B.

The light receiving angle when receiving reflected light and the like is not particularly limited, and may be appropriately set so that the amount of light received by the reflected light or the like becomes maximum. In addition, the "light receiving angle" means the angle between the light with the maximum amount of reflected light in the non-latent image area B and the normal to the horizontal plane.

In addition, in the photographing method of the latent image printed matter according to this embodiment, an inspection step may be performed after the photographing step, and the inspection step is to confirm whether the latent image ink layer 11 is defective in printing. In this case, the inspection method for confirming the presence or absence of printing defects is not particularly limited, and a conventionally known method can be adopted.

<Photographic device for latent image printed matter of solid preparation>

Next, a photographing device used in a photographing method of a latent image print will be described below based on FIG. 2. FIG. 2 is a schematic diagram showing an outline of a photographing device used in a photographing method.

As shown in FIG. 2, the photographing device of this embodiment includes at least: a light irradiation mechanism 21 for irradiating the solid preparation 10 with irradiation light; and an imaging mechanism 22 for photographing the solid preparation 10.

The light irradiation means 21 is not particularly limited as long as it can irradiate light including ultraviolet rays in a wavelength range of 200 nm to 400 nm. Examples thereof include various known light irradiation mechanisms such as a black light lamp, a mercury lamp, a metal halide lamp, a xenon lamp, and an LED (Light Emitting Diode).

In addition, when the light irradiation mechanism 21 is a mechanism that irradiates light including visible light and the like, and it is intended to irradiate the solid preparation 10 only with ultraviolet rays in the above-mentioned wavelength region, light in a wavelength region other than the wavelength region (for example, Visible light, infrared light, etc.) is irradiated by the first optical filter 23 that is cut off or attenuated. Alternatively, a light irradiation mechanism having such a first optical filter 23 built in may be used as the light irradiation mechanism 21.

The photographing mechanism 22 is a mechanism that receives the reflected light or fluorescent light reflected by the non-latent image area B by the irradiation of the irradiation light, and photographs the images of the latent image area A and the non-latent image area B. More specifically, a conventionally known ultraviolet camera or the like can be cited as the imaging mechanism 22.

In addition, when it is desired to control the wavelength of the light received by the imaging mechanism 22, light can also be received by the imaging mechanism 22 through a second optical filter 24 such as a wavelength filter. This makes it possible, for example, to make the wavelength region of the received light coincide with the wavelength region of the irradiated light. The second optical filter 24 is not particularly limited, and examples thereof include a conventionally known wavelength filter that can block or attenuate visible light, infrared light, and the like. Alternatively, a photographing mechanism having the second optical filter 24 built in may be used as the photographing mechanism 22.

(Embodiment 2)

<Latent image print of solid preparation>

The latent image printed matter of the solid preparation of the second embodiment will be described below. FIG. 3 is an explanatory view schematically showing a latent image printed matter of the solid preparation of the present embodiment. In the following, the same components as those in the first embodiment are denoted by the same reference numerals, and descriptions of the components are omitted.

As shown in FIG. 3, the latent image printed matter of this embodiment is different from the latent image printed matter of Embodiment 1 in that another non-latent image area C is further provided, and the other non-latent image area C is provided with a visible ink layer. 12 and a visible image is formed. The visible ink layer 12 is provided on the surface of the solid preparation 10, and the latent image ink layer 11 is laminated on the visible ink layer 12 in a state of being partially overlapped.

Here, in the present specification, the "visible image" means an image that can be recognized under an environment in which visible light (wavelength region of 400 nm to 760 nm) is irradiated. Furthermore, the visible image may include an image that is latently imaged and difficult to recognize in an environment irradiated with ultraviolet rays having a wavelength range of 200 nm or more and less than 400 nm. An image printed as a visible image can be printed by an inkjet method using, for example, an inkjet aqueous ink described later.

[Other non-latent image areas]

The other non-latent image region C is a region where a visible image is formed by the visible ink layer 12 that absorbs at least visible light (wavelength region 400 nm to 760 nm).

In the case where the latent image ink layer 11 and the visible ink layer 12 are laminated in a state where at least a portion is overlapped as in this embodiment, the latent image ink layer 11 is preferably laminated on the visible ink layer 12. Thereby, when the latent image ink layer 11 is light-transmissive to visible light, visible light passes through the latent image ink layer 11, and thus a visible image can be identified without being hindered by the latent image ink layer 11. As a result, even when the area of the printable area is small, more information can be recorded on the surface of the solid preparation 10. When developing the latent image, the entire area of the latent image ink layer 11 may be irradiated with ultraviolet rays. As a result, the latent image can be developed in a good state.

It can be seen that the ink layer 12 may be a layer that absorbs ultraviolet rays in a wavelength range of 200 nm to 400 nm, but is preferably a layer that transmits or reflects the ultraviolet rays. Therefore, since the non-latent image area B is an area that reflects ultraviolet light and / or emits fluorescence, the visible image formed by the visible ink layer 12 when the ultraviolet light is irradiated can be converted into a latent image by the ultraviolet light. . As a result, when the latent image of the latent image area A is developed, it is possible to avoid the superimposed recognition with the visible image, so that the visibility of the developed latent image can be improved.

The visible ink layer 12 is preferably a layer composed of a dry film of an aqueous ink for visible images described later. The dried film can be formed by directly printing on the surface of the solid preparation 10 using an aqueous ink for visible images, for example, by an inkjet method or the like. In addition, it is preferable that the visible ink layer 12 contains at least a component having a light absorption property with respect to visible light (hereinafter, sometimes referred to as a "visible light absorption component"). Furthermore, the visible light absorbing component is preferably contained uniformly in the visible ink layer 12. Examples of visible light absorbing components include dyes and pigments (for details, they will be described later). The thickness of the visible ink layer 12 is not particularly limited, and can be appropriately set as needed.

Moreover, this embodiment is not limited to the case where the latent image ink layer 11 is laminated on the visible ink layer 12. For example, the latent image ink layer 11 and the visible ink layer 12 may be respectively disposed in different regions on the surface of the solid preparation 10. Thereby, even when the visible ink layer 12 is a layer that absorbs the ultraviolet rays in the above-mentioned wavelength region, and when the latent image is not irradiated under the ultraviolet light irradiation, it can be prevented from being recognized by overlapping with the developed latent image, which can prevent the The visibility of both the developed latent image and the visible image is reduced. In addition, the visible ink layer 11 may be laminated on the latent image ink layer 11.

[Difference between order values of non-latent image area and other non-latent image areas]

When the non-latent image area B and other non-latent image areas C are simultaneously irradiated with visible light, the difference between the order values of the other non-latent image areas C relative to the non-latent image area B is 5 or more, preferably 15 or more, more Preferably it is 30 or more. By setting the difference in the gradation value to 5 or more, a good visual recognition (or recognition) of a visible image (visible ink layer 12) under visible light irradiation can be achieved.

The so-called "gradation value" in this embodiment is the same as that described in the first embodiment. In addition, the "difference in the gradation value" in this embodiment means a value obtained by subtracting the average value of the gradation values of the non-latent image area B from the average value of the gradation values of the other non-latent image area C. Furthermore, the average value of the gradation value means the average value of the gradation values of a plurality of pixels in the image data of the other non-latent image area C or the non-latent image area B.

The better visibility of the visible image under visible light irradiation can be controlled by the combination of the peak wavelength of the visible light absorbed by the visible light absorbing component contained in the visible ink layer 12 and the wavelength of the visible light irradiated. Alternatively, the visible light absorbing ability of the visible ink layer 12 can be improved by adjusting the concentration of the visible light absorbing component contained in the visible ink layer 12, and the order values of other non-latent image regions C relative to the non-latent image regions B can be increased. The way to maximize the difference is controlled.

When the non-latent image area B and other non-latent image areas C are simultaneously irradiated with at least ultraviolet light, the difference between the order values of the other non-latent image areas C relative to the non-latent image area B is preferably less than 5 . By setting the difference between the gradation values to less than 5, it becomes difficult or reduced to visually recognize (or recognize) a visible image (visible ink layer 12) under ultraviolet irradiation. That is, a visible image can be latently imaged under the irradiation of light including ultraviolet rays in the above-mentioned wavelength region. In order to make a visible image latent image, it can be achieved by setting the visible ink layer 12 as a layer that transmits or reflects ultraviolet rays.

[Visible image with water-based ink]

As a constituent material of the visible ink layer 12 forming other non-latent image regions C, in this embodiment, it is preferable to use a water-based ink for visible images having edible properties. The visible image water-based ink contains a visible image water-based ink composition.

In the case of using a dye as a colorant (visible light absorbing component) in the aqueous ink composition for visible images, the aqueous ink composition for visible images contains at least one dye and water as a main solvent.

The dye is not particularly limited, and examples thereof include conventionally known edible synthetic pigments (synthetic tar pigments) and edible natural pigments.

Examples of the edible synthetic pigment include at least one selected from the group consisting of an azo dye, a triphenylmethane dye, a xanthene dye, and an indigo dye. Furthermore, the azo dye is not particularly limited, and examples thereof include at least one selected from the group consisting of Red No. 2, Red No. 102, Red No. 40, Yellow No. 4, and Yellow No. 5. The triphenylmethane-based dye is not particularly limited, and examples thereof include at least one of Blue No. 1 and Green No. 3. The diphenylpyranopyran dye is not particularly limited, and examples thereof include at least one selected from the group consisting of Red No. 3, Red No. 104, Red No. 105, and Red No. 106. Examples of the indigo dye include Blue No. 2.

The edible natural pigment includes at least one selected from the group consisting of cochineal red pigment, sodium copper chlorophyll, cocoa pigment, and caramel pigment.

Furthermore, in the present embodiment, a lake pigment obtained by subjecting the dyes exemplified above to lake formation using a known lake formation agent may be used.

These dyes, etc. can be used individually or in mixture of 2 or more types as needed suitably. In addition, these dyes and the like comply with the standards for pharmaceutical additives, the Japanese Pharmacopoeia, and the Japanese Food Additives Regulations as specified in the Japanese Pharmaceutical Affairs Law.

The dyes and the like exemplified above show light absorption to visible light. In addition, these dyes show light transmittance to ultraviolet rays in a wavelength range of 200 nm to 400 nm. Therefore, when these dyes are used as a constituent material of the visible ink layer 12, a visible ink layer 12 can be formed, which can be visually recognized under visible light irradiation, and under ultraviolet radiation in the above-mentioned wavelength region, Since the non-latent image region B is a region that reflects the ultraviolet light and / or emits fluorescence, it becomes difficult to visually recognize the latent image. The dyes exemplified above can be used alone or in combination of two or more. In addition, it is preferable that these dyes conform to the standards of the pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations as stipulated in the Japanese Pharmaceutical Affairs Law.

The content of the dye is not particularly limited, but it is usually within a range of 0.2% to 20% by mass, and preferably 1% to 10% by mass, relative to the total mass of the aqueous ink composition for visible images.

The water-based ink composition for visible images of this embodiment may further contain a surface tension adjuster. The surface tension adjusting agent is not particularly limited as long as it is a compound that complies with standards such as the Japanese Pharmaceutical Affairs Law. Specific examples include polyglycerol fatty acid esters, decaglyceryl caprylate, hexaglyceryl laurate, and hexaoleate Glycerides, etc. These can be used individually by 1 type or in mixture of 2 or more types. The content of the surface tension adjuster is not particularly limited, and it is usually within a range of 0.5% by mass to 5% by mass based on the total mass of the aqueous ink composition for visible images.

Moreover, the water-based ink composition for visible images of this embodiment may contain a wetting agent. The humectant is not particularly limited as long as it is a compound that complies with standards such as the Japanese Pharmaceutical Affairs Law, and specific examples thereof include propylene glycol and glycerin. The amount of the humectant to be added is not particularly limited, and it is usually within a range of 20% by mass to 50% by mass based on the total mass of the aqueous ink composition.

In the aqueous ink composition for visible images of this embodiment, other additives may be blended. However, when used as inkjet inks for solid preparations such as pharmaceuticals, it is preferred that the additives comply with the standards of pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations as specified in the Japanese Pharmaceutical Affairs Law. . Examples of the additives include water-soluble resins, organic amines, surfactants, pH adjusters, chelating agents, preservatives, viscosity adjusters, and antifoaming agents. The content of these additives is not particularly limited, and can be appropriately set as needed.

In the aqueous ink composition for visible images of this embodiment, a pigment may be used as a colorant (visible light absorbing component). In this case, the water-based ink composition for visible images contains at least a pigment composition and water as a main solvent.

The pigment composition is a composition containing at least a pigment and a pigment dispersant. The content of the pigment composition is not particularly limited, and is usually in the range of 0.5% by mass to 20% by mass in terms of pigment fraction based on the total mass of the aqueous ink composition for visible images.

Examples of the pigment include carbon black and black iron oxide. These pigments are light absorbing to visible light. Therefore, in the case where the non-latent image area B reflects visible light, by using these pigments as the constituent material of the visible ink layer 12, the order of the other non-latent image area C with respect to the non-latent image area B can be increased. The difference in values. Furthermore, these pigments are also light-absorptive to ultraviolet rays in a wavelength range of 200 nm to 400 nm. Therefore, when the latent image composed of the latent image ink layer 11 is developed by irradiating ultraviolet rays, the visible image composed of the visible ink layer 12 is also visually recognized on the surface of the solid preparation 10 together with the developed latent image. . Therefore, in the case of using these pigments, it is preferable that the developed latent image can be sufficiently recognized (discriminated). Specifically, the visible ink layer 12 can be printed on a region different from the latent image ink layer 11, or the concentration of the pigment can be reduced within a range that can sufficiently ensure the visibility during irradiation with visible light. The pigments exemplified above may be used alone or in combination of two or more. In addition, these pigments are preferably in accordance with the standards of the pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations as stipulated in the Japanese Pharmaceutical Affairs Law.

The content of the pigment is not particularly limited, and it may be appropriately set in consideration of the preservation property, viscosity, and image density of the aqueous ink composition for visible images. Generally, the content of the pigment is in a range of 0.5% to 40% by mass based on the total mass of the pigment composition.

As the pigment dispersant, a pigment dispersant generally used in an aqueous ink composition for inkjet can be used. Specific examples include nonionic surfactants and anionic surfactants. Examples of the nonionic surfactant include polyoxyethylene hydrogenated castor oil, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, and polyoxyethylene mountain arrow. Polyoxyethylene alkyl ethers such as ethers, polysorbates, deca glyceryl oleate, and the like. Examples of the anionic surfactant include sodium polyacrylate. These can be used individually or in mixture of 2 or more types. However, when the pigment composition of this embodiment is used for printing on the surface of tablets such as pharmaceuticals or foods, it is preferable to use pharmaceutical additives, Japanese Pharmacopoeia, or Japanese foods that comply with the provisions of the Japanese Pharmaceutical Affairs Law. A compound that is the basis of the Addendum.

The pigment composition contains a dispersion medium for dispersing the pigment. As the dispersion medium, the same dispersion medium as that used for the pigment composition in the latent image water-based ink composition of Embodiment 1 can be used. medium. Therefore, the details of the dispersion medium are omitted.

The water-based ink composition for visible images of this embodiment contains water (water as a main solvent). As the water, pure water such as ion-exchanged water, ultra-filtered water, reverse osmosis water, or distilled water, or water from which ionic impurities have been removed, such as ultra-pure water, is preferably used. The content of water is not particularly limited, and can be appropriately set as needed.

In the aqueous ink composition for visible images of this embodiment, a surface tension adjusting agent, a wetting agent (anti-drying agent), an anti-fading agent, an emulsifying stabilizer, a penetration enhancer, an ultraviolet absorber, a preservative, and Additives such as mold agents, pH adjusters, viscosity adjusters, dispersion stabilizers, rust inhibitors, and chelating agents. However, when it is used as an inkjet ink for tablets such as pharmaceuticals, it is preferably an additive that complies with standards such as the Japanese Pharmaceutical Affairs Law.

The surface tension adjusting agent is not particularly limited as long as it is a compound that complies with standards such as the Japanese Pharmaceutical Affairs Law. Specific examples include glycerin fatty acid esters and polyglycerol fatty acid esters. Examples of the glycerin fatty acid ester include deca glyceryl caprylate and deca glyceryl laurate. The amount of the surface tension adjusting agent to be added is not particularly limited, and is usually set so that the surface tension of the latent image water-based ink composition can be adjusted to a range of 25 mN / m to 40 mN / m.

The wetting agent is not particularly limited as long as it is a compound that complies with standards such as the Japanese Pharmaceutical Affairs Law, and specific examples thereof include propylene glycol and glycerin. The amount of the humectant added is not particularly limited, and it is usually in the range of 3% by mass to 50% by mass based on the total mass of the aqueous ink composition for visible images.

The manufacturing method of a pigment composition and an aqueous ink composition for visible images is not specifically limited, A conventionally well-known method can be used.

<Printing method of latent image printed matter of solid preparation>

The method for printing the latent image printed matter of the solid preparation of this embodiment at least includes a visible image printing step of printing a visible image on the surface of the solid preparation; and a latent image printing step of printing a latent image on the surface of the solid preparation.

The visible image printing step is a step of forming a visible image by printing the visible ink layer 12 on the surface of the solid preparation 10 using an aqueous ink for visible images. The method for forming the visible ink layer 12 is not particularly limited, but printing using an inkjet method is preferred. More specifically, the printing of the visible ink layer 12 using the inkjet method is performed by a method in which a water-based ink of a visible image is ejected as droplets from a fine nozzle to make the droplets adhere On the solid preparation 10. The method of ejecting water-based ink for visible images is not particularly limited. For example, continuous ejection type (charge control type, spray type, etc.), and on-demand type (piezoelectric method, temperature control method, electrostatic suction method) can be used. Etc.) and other well-known methods. Printing conditions such as the amount of ink droplets to be discharged and the printing speed are not particularly limited, and can be appropriately set as needed.

In addition, the visible image printing step may include a drying step of drying the visible image adhered to the surface of the solid preparation 10 by droplets of water-based ink. The drying method is not particularly limited, and in addition to hot air drying, natural drying may be performed. In addition, the drying conditions such as the drying time and the drying temperature are not particularly limited, and can be appropriately set in accordance with the amount of droplets ejected, the type of the aqueous ink composition for visible images, and the like.

The latent image printing step is a step of forming a latent image by printing a latent image ink layer 11 by using the latent image aqueous ink on the surface of the solid preparation 10. The method for forming the latent image ink layer 11 is not particularly limited, and, as in the case of the visible image printing step, printing by an inkjet method is preferred. The printing of the latent image ink layer 11 by the inkjet method is the same as that in the visible image printing step except that the latent image water-based ink is used. In addition, the latent image printing step may include a drying step of drying the latent image attached to the surface of the solid preparation 10 with droplets of an aqueous ink. The drying method or drying conditions are the same as those in the visible image printing step.

Here, when the printed area of the visible image (other non-latent image area C) and the printed area of the latent image (latent image area A) are different from each other on the surface of the solid preparation 10, the visible image printing step The sequence with the latent image printing step is not particularly limited. For example, in the case where the latent image printing step is performed first than the visible image printing step, the latent image may be printed in a region different from a predetermined area for printing the visible image. On the other hand, when the printed area of the visible image and the printed area of the latent image overlap at least partly on the surface of the solid preparation 10 as in this embodiment, it is preferable to first print in the visible image printing step. After the image is visible, the latent image is printed in the latent image printing step. Thereby, in the area where the visible image and the latent image overlap, the latent image ink layer 11 can be laminated on the visible ink layer 12, and when the latent image ink layer 11 is developed, ultraviolet rays can be irradiated to the latent image ink layer. 11 of the entire area.

<Photographic method and device for latent image printed matter of solid preparation>

Next, a photographing method of a latent image printed matter of the solid preparation of the present embodiment will be described below.

The method of photographing the latent image printed matter of the solid preparation of this embodiment is the same as the case of Embodiment 1, and includes at least a developing step to develop the latent image, and a photographing step to develop the latent image in the developing step. Film for photography.

The developing step is performed by irradiating the latent image region A, the non-latent image region B, and other non-latent image regions C with irradiation light including at least ultraviolet rays. By the irradiation of the irradiation light, ultraviolet rays are absorbed in the latent image ink layer 11 of the latent image region A, and ultraviolet rays are reflected and / or fluorescent light is emitted in the non-latent image region B. On the other hand, when the visible ink layer 12 is a layer that transmits or reflects ultraviolet rays, the difference between the order values of the other non-latent image regions C and the non-latent image regions B becomes less than 5, so that the visible ink can be made. The visible image formed by the layer 12 is latent imaged. However, when the visible ink layer 12 is the same as the latent image ink layer 11 as a layer that absorbs ultraviolet rays, the difference between the order values of the other non-latent image regions C with respect to the non-latent image region B becomes 5 or more, and the visible ink layer 12 It can also be identified under ultraviolet radiation.

The irradiation conditions of ultraviolet rays are the same as the irradiation conditions described in the first embodiment. Therefore, the detailed description of the irradiation conditions is omitted.

The photographing step is performed by receiving reflected light reflected from the non-latent image area B and / or fluorescent light generated from the non-latent image area B (hereinafter, referred to as "reflected light"). Etc. ", and photographed the developed latent image area A, non-latent image area B, and other non-latent image areas C in the developing step. Here, when the visible ink layer 12 is composed of a layer that reflects ultraviolet rays, the reflected light reflected by the visible ink layer 12 may also be received. The light receiving conditions are the same as the light receiving conditions described in the first embodiment. Therefore, detailed descriptions of the light receiving conditions are omitted.

In addition, in the photographing method of the latent image printed matter of this embodiment, an inspection step may be performed after the photographing step. This inspection step is performed in addition to the latent image ink layer 11 and also confirms whether or not the ink layer 12 is defective in printing.

In addition, the photographing apparatus used in the photographing method of the latent image printed matter of the present embodiment may have the same configuration as the photographing apparatus used in the first embodiment. Therefore, the detailed description of the photographing device is omitted.

(Embodiment 3)

The inspection method of the edible matter according to this embodiment does not use a special photographic device such as an ultraviolet camera, and easily recognizes the potential of at least a part of the surface of the edible matter in a normal environment in which visible light such as a fluorescent lamp is irradiated. Shadow and check.

In the present specification, the "edible substance" means an edible solid substance. Specifically, for example, in addition to solid foods, edible films, edible tablets, and the like are listed. Furthermore, solid preparations are also included in edible materials.

Hereinafter, a latent image printed matter as a solid preparation of an edible substance will be described. FIG. 4 is an explanatory view schematically showing a latent image printed matter of the solid preparation of the present embodiment.

As shown in FIG. 4, the latent image print of the present embodiment is provided with a latent image ink layer 11 on at least a part of the surface of the solid preparation 20. The latent image ink layer 11 forms a printed image as a latent image. In addition, the latent image printed matter of this embodiment has at least: a latent image area A where the latent image ink layer 11 forms a latent image; and a non-latent image area D where no latent image is formed.

Here, the image printed as a latent image is the same as in the case of the first and second embodiments, and for example, the ink can be printed by an inkjet method using an aqueous inkjet ink. In addition, for edibles other than solid preparations, in addition to the inkjet method, gravure printing or flexographic printing can also be used.

[Latent image area]

The latent image region A is a region where a latent image is formed by the latent image ink layer 11, and the latent image ink layer 11 absorbs ultraviolet rays in a wavelength range of 200 nm or more and less than 400 nm. The above-mentioned wavelength region is more preferably in a range of 260 nm to 380 nm, and particularly preferably in a range of 280 nm to 360 nm. The latent image ink layer 11 is preferably light-transmissive to visible light. In addition, "light transmittance" in this specification means the property which transmits at least a part of incident visible light. In addition, the meaning of light transmittance includes a case where the latent image ink layer 11 is colored, and a case where the latent image ink layer 11 is colored.

In the latent image region A, other ink layers or coatings formed on an image that can be viewed under visible light may also be provided. Since the latent image ink layer 11 has light permeability to visible light, the visibility of the other ink layers can be ensured even when other ink layers are disposed under the latent image ink layer 11. Examples of the coating layer include an overcoat layer and an undercoat layer for covering the latent image ink layer 11 for protection.

The latent image ink layer 11 is preferably a layer composed of a dry coating film (dried coating film) of an aqueous inkjet ink (the details will be described later). The dry film can be formed by printing directly on the surface of the solid preparation 20 using an inkjet water-based ink, for example, by an inkjet method or the like. In addition, it is preferable that the latent image ink layer 11 contains at least a component (hereinafter, sometimes referred to as an “ultraviolet absorbing component”) having a light absorptivity to ultraviolet rays in the above-mentioned wavelength range. Furthermore, it is preferable that the ultraviolet absorbing component is uniformly contained in the latent image ink layer 11. Examples of the ultraviolet absorbing component include titanium oxide (TiO ₂ ) particles and zinc oxide particles as pigments. The thickness of the latent image ink layer 11 is not particularly limited, and can be appropriately set as needed.

[Non-latent image area]

The non-latent image region D is a region where ultraviolet light (hereinafter, referred to as "irradiated light") including at least the above-mentioned wavelength region is irradiated, and ultraviolet rays are emitted as visible light in the visible light region.

In order for the non-latent image region D to exhibit a fluorescent property when it is irradiated with ultraviolet rays in the above-mentioned wavelength region, it is preferable that the solid preparation 20 contains a visible light region that absorbs ultraviolet rays in the wavelength region as excitation light. Fluorescent component of fluorescence. Such a fluorescent component is not particularly limited as long as it is an edible fluorescent component, and specific examples thereof include: NAD (P) H (Nicotinamide adenine dinucleotide phosphate; tobacco nicotine adenine dinucleotide phosphate) Glycosyl phosphate) (excitation wavelength 340nm, fluorescence wavelength 450nm), chlorophyll (excitation wavelength 465nm or 665nm, fluorescence wavelength 673nm or 726nm), collagen (excitation wavelength range 270nm to 370nm, fluorescence wavelength range 305nm To 450nm), bistyrosine (excitation light wavelength 325nm, fluorescence wavelength 400nm), saccharification adduct (excitation light wavelength 370nm, fluorescence wavelength 450nm), flavin (excitation light wavelength range 380nm to 490nm, fluorescence wavelength Autofluorescence components such as 520nm to 560nm), melanin (excitation light wavelength range 340nm to 400nm, fluorescence wavelength range 360 to 560), elastin (excitation light wavelength 360nm, fluorescence wavelength 410nm) and the like. These autofluorescent components are contained in animal or plant-derived raw materials (specifically, starch, sugar, protein, etc.), and the raw materials are generally used in commercially available tablets and the like. The fluorescent components exemplified above may be used alone or in combination of two or more.

Furthermore, even when the solid preparation 20 itself contains ultraviolet absorbing components such as titanium oxide, a non-latent image can be formed by providing a fluorescent layer containing a fluorescent component on the surface of the solid preparation 20 for ultraviolet rays in the above-mentioned wavelength region. Area D.

In addition, the non-latent image region D may include a case where at least a part of the visible light is reflected or absorbed under the irradiation of visible light. A coating or the like may be provided in the non-latent image region D.

[Latent image water-based ink]

As a constituent material of the latent image ink layer 11 forming the latent image region A, the latent image water-based ink according to the first and second embodiments can be used. Furthermore, the latent image water-based ink composition and the like contained in the latent image water-based ink and the pigment composition and the like contained in the latent image water-based ink composition can also be used in the same manner as in Embodiment 1 and Embodiment 2. Same composition, etc. Therefore, detailed descriptions of these compositions are omitted.

[Pigment composition]

The pigment composition contained in the latent image water-based ink composition is a pigment containing at least titanium oxide (TiO ₂ ) particles and / or zinc oxide (ZnO) particles, as in the case of Embodiment 1 and Embodiment 2. (Ultraviolet absorbing component), and a composition of a pigment dispersion of sodium polyacrylate as a pigment dispersant. In addition, the manufacturing method of the pigment composition of this embodiment is also the same as that of Embodiment 1 and Embodiment 2. Therefore, detailed descriptions of these are omitted.

<Printing method of latent image printed matter of solid preparation>

The method for printing the latent image printed matter of the solid preparation of the present embodiment is the same as that of the first embodiment, and includes at least a latent image printing step. The latent image printing step is to print a latent image on the surface of the solid preparation 20. Therefore, a detailed description of this printing method is omitted.

<Inspection method of latent image printed matter of solid preparation>

Next, a method for inspecting a latent image print of the solid preparation of the present embodiment will be described below.

The inspection method of this embodiment includes at least a development step to develop a latent image, and an inspection step to inspect the developed latent image in the development step.

The developing step is performed by irradiating the latent image region A and the non-latent image region D with irradiation light including at least ultraviolet rays. The latent image ink layer 11 of the latent image area A absorbs ultraviolet rays by the irradiation of the irradiation light. On the other hand, in the non-latent image region D, ultraviolet rays are used as excitation light to emit fluorescent light in a visible region. As a result, in the latent image area A, the latent image can be visually recognized as a region with a lower brightness than the non-latent image area D that emits fluorescence, so that the latent image formed by the latent image ink layer 11 can be developed. Into.

The wavelength range of the ultraviolet rays is in a range of 200 nm or more and less than 400 nm, and can be appropriately set according to the type of the ultraviolet absorbing component contained in the latent image ink layer 11. In addition, the light intensity (μW / cm ² ) at the time of emission of the irradiated light can be appropriately set depending on the type of the ultraviolet absorbing component, the content in the latent image ink layer 11, the degree of ultraviolet light absorption, and the like. For example, in the case where titanium oxide or zinc oxide is used as an ultraviolet absorbing component, the light intensity is in the range of 4000 μW / cm ² to 35000 μW / cm ² , more preferably 5000 μW / cm ² to 30,000 μW / cm ² , and most preferably 10000 μW / cm ² to 20000 μW / cm ² . Furthermore, the irradiation angle of the solid preparation 20 by the irradiation light is not particularly limited, and can be appropriately set. In addition, the "irradiation angle" means the angle which the irradiation direction of the irradiation light which irradiates the solid preparation 20 and the horizontal plane on which the solid preparation 20 is mounted.

The inspection step is performed by photographing the developed latent image in the developing step visually or by using an imaging mechanism whose receiving wavelength is a visible light region. The reason for visual inspection in this embodiment is that in the non-latent image area D, fluorescent light in the visible light region is emitted. On the other hand, in the latent image area A, the latent image ink layer 11 absorbs ultraviolet rays, and the brightness is relatively high. A region where the non-latent image region D is low is recognized.

In addition, in the case of using a photographing mechanism, it is performed by receiving fluorescence generated in the non-latent image area D, and comparing the developed latent image area A and the non-latent image in the developing step. The shadow area D is photographed. The light receiving condition is preferably set so as to display the maximum sensitivity in a wavelength region (400 nm to 760 nm) of the fluorescent light generated in the non-latent image region D. Thereby, the amount of received light can be increased, and the latent image area A and the non-latent image area D can be photographed with good contrast. When the light receiving wavelength sensitivity is low or there is no light receiving sensitivity, it is sometimes difficult to photograph the developed latent image area A and the non-latent image area D.

The light receiving angle when receiving fluorescent light is not particularly limited, and it may be appropriately set so that the light receiving amount of the fluorescent light becomes the maximum. In addition, the "light receiving angle" means the angle between the light with the maximum amount of fluorescent light in the non-latent image region D and the normal to the horizontal plane.

In addition, in the inspection step, when it is confirmed whether the latent image ink layer 11 is defective in printing, a conventionally known inspection method can be adopted. For example, an ink layer having no printing defects is irradiated with ultraviolet rays, an ink layer that absorbs ultraviolet rays, and a non-latent image region D that emits fluorescence are photographed in advance to be a reference ink layer. Then, the ink layer to be inspected (hereinafter referred to as "inspected ink layer") was also irradiated with ultraviolet rays under the same irradiation conditions as the reference ink layer, and photographed under the same imaging conditions as the reference ink layer. After that, the photographic data of the reference ink layer and the ink layer to be inspected are compared to determine whether there is a printing failure in the ink layer to be inspected. With this, it is possible to check whether the latent image ink layer 11 is defective in printing.

The contrast in the latent image area A and the non-latent image area D when the irradiation light is irradiated can be controlled by, for example, adjusting the light intensity of the irradiation light. Specifically, by appropriately controlling the light intensity of the irradiated light, the difference in contrast between the latent image area A and the non-latent image area D can be maximized, so that the identification of the latent image can be performed well. For example, when the difference in contrast between the latent image area A and the non-latent image area D is small because the light intensity of the light source irradiating the light is too weak, the difference in contrast can be increased by increasing the light intensity of the light source. In addition, in the case of using a photography mechanism, when the light intensity of the light source is too large and the photography is overexposed, and the contrast between the latent image area A and the non-latent image area D cannot be identified, it can be increased by reducing the light intensity of the light source. The difference in contrast. In addition, the difference in contrast between the latent image area A and the non-latent image area D can be controlled by an optimal combination with the wavelength of at least ultraviolet rays included in the irradiated light, in addition to the light intensity of the irradiated light. Specifically, it is preferable to set it so that the wavelength of ultraviolet rays and the wavelength of ultraviolet rays absorbed in the latent image ink layer 11 at least partially overlap. Alternatively, the ultraviolet absorption capacity in the latent image area A can be increased or decreased by adjusting the concentration of the ultraviolet absorbing component contained in the latent image ink layer 11, so as to control the latent image area A and the non-latent image area D. The difference in contrast.

[Example]

Hereinafter, preferred embodiments of the present invention will be described in detail by way of illustration. However, the materials and contents described in the following examples are not limited to the scope of the present invention as long as they are not particularly limited.

(Preparation of latent image water-based ink composition A)

First, a pigment composition is produced. That is, titanium oxide nano particles as a pigment, sodium polyacrylate as a pigment dispersant, and pure water as a dispersion medium are added to a container, and a disperser (paint shaker, manufactured by Nissho Asada Iron Works Co., Ltd.) is used. ), Disperse at normal temperature for 24 hours (dispersion time). In addition, during the dispersion, zirconia beads were mixed. Thereby, a pigment composition is produced. In addition, as the titanium oxide nano particles, TTO-55A (type, crystal structure: rutile type, average primary particle size: 40 nm) manufactured by Nissho Ishihara Industry Co., Ltd. was used. Furthermore, the shape of the titanium oxide nanoparticle is substantially spherical. As sodium polyacrylate, TEGO Dispers 715W (mass average molecular weight 3000) manufactured by Evonik was used.

Next, a polyglyceryl fatty acid ester (trade name: SY Glister, manufactured by Nissho Sakamoto Pharmaceutical Co., Ltd.) as a surface tension adjuster, propylene glycol and pure water as a wetting agent are added to the pigment composition so as to become It was prepared as a mixing ratio shown in Table 1 below, and stirred with a disperser. Thereby, a latent image water-based ink composition A was produced.

In addition, during the production of the pigment composition and the latent image water-based ink composition A, no air bubbles were generated, so the defoaming step performed by adding an antifoaming agent was not performed. In addition, the numerical values in the following Table 1 are expressed as mass% relative to the total mass of the latent image water-based ink composition A unless otherwise specified. In addition, each material complies with the standards for pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations as specified in the Japanese Pharmaceutical Affairs Law.

(The values in the table are expressed as mass% unless otherwise specified.)

(Preparation of latent image water-based ink composition B)

First, a pigment composition is produced. That is, zinc oxide nano particles as a pigment, sodium polyacrylate as a pigment dispersant, and pure water as a dispersion medium are added to a container, and a disperser (paint shaker, manufactured by Nissho Asada Iron Works Co., Ltd.) is used. ), Disperse at normal temperature for 24 hours (dispersion time). In addition, during the dispersion, zirconia beads were mixed. Thereby, a pigment composition is produced. In addition, as zinc oxide nano particles, FINEX-30 (model, with an average primary particle size of 35 nm, manufactured by Nissho Chemical Co., Ltd.) was used, and the surface was not subjected to silica hydrate (aqueous silica). Hydrophilization treatment). Furthermore, the shape of the zinc oxide nanoparticle is substantially spherical. As sodium polyacrylate, TEGO Dispers 715W (mass average molecular weight 3000) manufactured by Evonik was used.

Next, a polyglyceryl fatty acid ester (trade name: SY Glister, manufactured by Nissho Sakamoto Pharmaceutical Co., Ltd.) as a surface tension adjuster, propylene glycol and pure water as a wetting agent are added to the pigment composition so as to become It was prepared as a mixing ratio shown in Table 2 below, and stirred with a disperser. Thereby, a latent image water-based ink composition B was produced.

In addition, during the production of the pigment composition and the latent image water-based ink composition B, no air bubbles were generated, so the defoaming step by adding an antifoaming agent was not performed. In addition, the numerical values in the following Table 2 are expressed as mass% relative to the total mass of the latent image water-based ink composition B unless otherwise specified. In addition, each material complies with the standards for pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations as specified in the Japanese Pharmaceutical Affairs Law.

(The values in the table are expressed as mass% unless otherwise specified.)

(Preparation of water-based ink composition A for visible images)

First, a pigment composition is produced. That is, carbon black as a pigment, polyoxyethylene alkyl ether as a pigment dispersant, and pure water as a dispersion medium are added to a container, and a disperser (paint shaker, manufactured by Nissho Asada Iron Works Co., Ltd.) is used. ), Disperse at normal temperature for 24 hours (dispersion time). In addition, during the dispersion, zirconia beads were mixed. Thereby, a pigment composition is produced.

Next, a polyglyceryl fatty acid ester (trade name: SY Glister, manufactured by Nissho Sakamoto Pharmaceutical Co., Ltd.) as a surface tension adjuster, propylene glycol and pure water as a wetting agent are added to the pigment composition so as to become It was prepared as a mixing ratio shown in Table 3 below, and was stirred with a disperser. Thereby, a water-based ink composition A for visible images was produced.

In addition, the numerical value in the following Table 3 is shown as mass% with respect to the total mass of the water-based ink composition A for a visible image, unless there is particular notice. In addition, each material complies with the standards for pharmaceutical additives, the Japanese Pharmacopoeia, or the Japanese Food Additives Regulations as specified in the Japanese Pharmaceutical Affairs Law.

(Preparation of water-based ink composition B for visible images)

Edible Green No. 3 as a dye, polyglycerin fatty acid ester (trade name: SY Glister, manufactured by Nissho Sakamoto Pharmaceutical Co., Ltd.) as a surface tension adjuster, propylene glycol and pure water as a wetting agent are added to become It was prepared as a mixing ratio shown in Table 4 below, and stirred with a disperser. Thereby, a visible image water-based ink composition B was produced.

(Light absorption spectrum of latent image water-based ink composition A and latent image water-based ink composition B)

For the latent image water-based ink composition A and the latent image water-based ink composition B, the ultraviolet-visible light region (190 nm to 500 nm) was confirmed using a spectrophotometer (trade name: UVmini-1240, manufactured by Nissho Shimadzu Corporation). ) In the absorption spectrum. Furthermore, when the prepared latent image water-based ink composition A was measured in the state of a stock solution, the concentration was too high. Therefore, the solution was measured by diluting 4000 times with pure water. In addition, a quartz cell having an optical path length of 1 cm was used for the measurement. The results are shown in Fig. 5.

(Light absorption spectrum of water-based ink composition A for visible images and water-based ink composition B for visible images)

For each of the visible image water-based ink composition A and the visible image water-based ink composition B, a UV-visible light was confirmed using a spectrophotometer (trade name: UVmini-1240, manufactured by Nissho Shimadzu Manufacturing Co., Ltd.). Absorption spectrum in the region (260nm to 800nm). Furthermore, when the prepared water-based ink composition A for visible images and water-based ink composition B for visible images were respectively measured in the state of the original solution, the concentration was too high, so the solution was diluted by 4000 times with pure water. Determination. In addition, a quartz cell having an optical path length of 1 cm was used for the measurement. The results are shown in Fig. 6.

(Measurement of mass average molecular weight of sodium polyacrylate)

The mass average molecular weight of sodium polyacrylate is based on polyethylene oxide (PEO; polyethylene oxide) / polyethylene glycol (PEG; polyethylene glycol) as a standard, and gel permeation chromatography (GPC) The value found.

(Measurement of average primary particle diameter and average dispersed particle diameter of titanium oxide nano particles and zinc oxide nano particles)

The average primary particle diameters and average dispersed particle diameters of the titanium oxide nano particles and zinc oxide nano particles are D50 and D99. Microtrac UPA-EX150 (trade name, manufactured by Nissho Nikkiso Co., Ltd.) is used for dynamic light scattering. And measured.

(Examples 1-1 to 1-7)

The latent image water-based ink composed of the aforementioned latent image water-based ink composition A was used to print a latent image on the plain ingot by an inkjet recording method. Printing is performed only on one side of the ingot, and it is performed in a one-pass method using an inkjet printer (KC 600dpi printing fixture equipped with a print head). The printing conditions were such that the mass of each droplet was 7 ng, and the amount of droplets was 7 pl. After printing, the printed image surface was dried by natural drying for 24 hours.

Next, for the plain tablets printed with latent images, the area (latent image area A) printed by the latent image water-based ink composition A in visible light (interior light) is determined relative to the non-latent image water-based ink composition. Difference in the degree value of the area printed by A (non-latent image area B). The photograph with the latent image printed on the plain tablet uses a built-in camera (brand name: iPhone6 (registered trademark), manufactured by Apple Inc.) in a smartphone.

The difference in the gradation values is obtained in the following manner. That is, the image data obtained by photographing with a digital camera is converted into 8-bit grayscale using commercially available software, and the gradation values of 256 stages from 0 to 255 in a plurality of pixels are obtained. Furthermore, the average value of the obtained gradation values is calculated, and the difference of the gradation values is calculated from the average value of the gradation values of the latent image area A minus the average value of the gradation values of the non-latent image area B.

Next, the latent image printed with a latent image was irradiated with ultraviolet rays (developing step) while changing the wavelength in each of the examples to develop the latent image for photographing (photographing step). As shown in Table 5 below, a xenon light source (trade name: MAX-303) manufactured by Nissho Asahi Kogyo Co., Ltd. was used as the irradiation mechanism. The wavelength of the irradiated ultraviolet rays was changed by using a mirror module attached to the xenon light source and various UV (ultra violet) band-pass filters (first optical filters) in combination. As shown in Table 7 below, the wavelengths of the ultraviolet rays are 260 nm, 280 nm, 300 nm, 320 nm, 340 nm, 360 nm, and 380 nm. The light intensity of the xenon light source was set to about 5000 μW / cm ² .

In addition, as a photographing mechanism used in the photographing step, an ultraviolet camera shown in Table 6 below was used. In addition, photography was performed in a dark room where outside light outside the xenon light source did not enter.

Then, the area printed by the latent image water-based ink composition A (latent image area A) under the irradiation of ultraviolet light of each wavelength is calculated with respect to the area (non-latent image area B) not printed by the latent image water-based ink composition A. ). The difference in the gradation values is obtained in the same manner as in the case of irradiation with visible light. The results are shown in Table 7 below.

(Examples 1-8 to 1-12)

In Examples 1-8 to 1-12, the wavelength of the ultraviolet light irradiated in the developing step was set to 260 nm, and the light intensity of the xenon light source was changed to the values shown in Table 7 below. Other than that, after developing each latent image in the same manner as in Example 1-1, photography was performed using an ultraviolet camera. In addition, in the same manner as in Example 1-1, the difference in the degree value of the latent image area A with respect to the non-latent image area B under the irradiation of ultraviolet rays with a wavelength of 260 nm was calculated. The results are shown in Table 8 below.

(Comparative Example 1-1 to Comparative Example 1-3)

In Comparative Examples 1-1 to 1-3, the wavelength of ultraviolet rays irradiated in the developing step was set to 260 nm, and the light intensity of the xenon light source was changed to the values shown in Table 7 below. Other than that, after developing each latent image in the same manner as in Example 1-1, photography was performed using an ultraviolet camera. In addition, in the same manner as in Example 1-1, the difference in the degree value of the latent image area A with respect to the non-latent image area B under the irradiation of ultraviolet rays with a wavelength of 260 nm was calculated. The results are shown in Table 8 below.

(Example 1-13)

The visible image water-based ink composed of the visible image water-based ink composition A described above was used to print a visible image on the plain ingot by an inkjet recording method. Printing is performed on only one side of the plain ingot, and is performed in one pass using an inkjet printer (KC 600dpi printing fixture equipped with a print head). The printing conditions were such that the mass of each droplet was 7 ng, and the amount of droplets was 7 pl. After printing, the printed image surface was dried by natural drying for 24 hours.

Next, a latent image was printed on the plain ingot by an inkjet recording method using the latent image water-based ink composed of the aforementioned latent image water-based ink composition A. The latent image is printed on the printed side of the visible image. In addition, as a latent image, a GS1QR code is printed. Furthermore, the printing method and printing conditions were the same as those in Example 1-1.

Secondly, for the ingots printed with visible images and latent images, the area (latent image area A) printed by the latent image water-based ink composition A under visible light (interior lamp) is compared with the unvisible image. The difference in the order value of the area (non-latent image area B) printed with the water-based ink composition A and the latent image water-based ink composition A. Furthermore, the difference in the degree value of the area (other non-latent image area C) printed with the water-based ink composition A of the visible image with respect to the non-latent image area B was also calculated. Digital cameras (trade name: PIAS ^TM -II, manufactured by QEA) are used for photography in which the visible image and the latent image are printed on the plain tablets.

The difference in the gradation values is obtained in the following manner. That is, for the image data obtained by photographing with a digital camera, a gradation value of 8-bit gray scale conversion calculated by the median method is obtained. Furthermore, the difference between the gradation values is calculated by subtracting the gradation value of the non-latent image area B from the obtained gradation value of the latent image area A.

Next, a plain ingot printed with a visible image and a latent image is irradiated with ultraviolet rays having a wavelength of 320 nm (developing step), the latent image is developed, and the visible image is latent imaged to perform photography (photographing step). The irradiation mechanism, irradiation conditions other than the wavelength range of ultraviolet rays, and the imaging device were set to be the same as those in Example 1-1.

Then, the area printed by the latent image water-based ink composition A (latent image area A) under ultraviolet light irradiation of each wavelength is calculated with respect to the water-based ink composition A and latent image water-based ink composition without visible images. Difference in the degree value of the area printed by A (non-latent image area B). Furthermore, the difference in the degree value of the area (other non-latent image area C) printed with the water-based ink composition A of the visible image with respect to the non-latent image area B was also calculated. The difference between these gradation values was determined in the same manner as in the case of the ultraviolet irradiation in Example 1-1. The results are shown in Table 9 below. Furthermore, when the difference in the degree value of the latent image area A with respect to the non-latent image area B is obtained, the brightness, color, contrast, and binarization of other non-latent image areas C can also be used. The processing makes the other non-latent image area C invisible, and is obtained as the difference in the degree value of the latent image area A with respect to areas other than the latent image area A.

(Examples 1-14)

In Example 1-14, compared with Example 1-13, the visible image water-based ink composition B was used instead of the visible image water-based ink composition A. Other than that, after developing each latent image in the same manner as in Example 1-13, photography was performed with an ultraviolet camera. In addition, in the same manner as in Example 1-13, the degree values of the latent image area A with respect to the non-latent image area B and the other non-latent image areas C with respect to the non-latent image area were respectively calculated under ultraviolet irradiation at a wavelength of 320 nm. The difference in the order of B. The results are shown in Table 9 below.

(Visibility and readability of developed latent image 1)

In Examples 1-1 to 1-11 and Comparative Examples 1-1 to 1-3, the visibility of the developed latent images under ultraviolet irradiation was evaluated. In addition, the plain ingots before ultraviolet irradiation were also evaluated for visibility under visible light. The evaluation criteria are as follows. The results are shown in Tables 7 and 8.

(Circle): The difference of the order value of the latent image area A with respect to the non-latent image area B is 5 or more, and a latent image can be recognized.

×: The difference in the order value between the latent image area A and the non-latent image area B is less than 5, making it difficult to recognize the latent image.

In Examples 1-13 and 1-14, the visibility of the visible image and the developed latent image under ultraviolet irradiation was evaluated, respectively. In addition, the plain ingots before ultraviolet irradiation were also evaluated for the visibility of visible images under visible light. The evaluation criteria are set as follows in addition to the above criteria. The results are shown in Table 9.

(Circle): The difference of the order value of the other non-latent image area C with respect to the non-latent image area B is 5 or more, and an image can be visually recognized.

×: The difference between the order values of the other non-latent image regions C and the non-latent image regions B is less than 5, making it difficult to visually recognize the image.

Furthermore, in Examples 1-13 and 1-14, the readability of the GS1QR code (hereinafter, referred to as "latent image GS1QR code") printed as a latent image was also evaluated. The evaluation was performed by raising the built-in camera of the smartphone (trade name: iPhone6 (trademark registration), manufactured by American Inc.) for the image taken in the above-mentioned visibility evaluation. ), Use the GS1QR code reading application (application name: GS1QR scodt, manufactured by Leontec), and read the latent image GS1QR code. The evaluation criteria are as follows. The results are shown in Table 9.

○: The latent image GS1QR code can be read, and the built-in information indicated is also correct.

△: The latent image GS1QR code can be read, but the built-in information indicated is incorrect.

×: Unable to read the latent image GS1QR code.

(Result 1)

As shown in Table 7, the difference in the order value of the latent image area A with respect to the non-latent image area B under the visible light of the plain ingot printed with the latent image is 1, and the latent image cannot be confirmed visually. Thus, it was confirmed that the latent image water-based ink composition A can print a good latent image by using titanium oxide nano particles as a pigment.

Secondly, as shown in Table 7, if the ingots of Examples 1-1 to 1-7 were irradiated with ultraviolet rays of a predetermined wavelength in the range of 260nm to 380nm, the water-based inks composed of latent images were used. In the latent image area A printed by the object A, the irradiated ultraviolet rays are absorbed, and as a result, the photography is black in the ultraviolet camera. On the other hand, in the non-latent image area B which is not printed with the latent image water-based ink composition A, the irradiated ultraviolet rays are reflected, and as a result, the photography is white in an ultraviolet camera. Furthermore, in each of Examples 1-1 to 1-7, the difference between the order value of the latent image area A and the non-latent image area B can be made 5 or more, and the latent image area A and the non-latent image can be made. The contrast between the regions B is such that the latent image is sufficiently recognized. Accordingly, it was confirmed that in the printing using the water-based ink composition A of the latent image containing titanium oxide nano particles in the pigment, the latent image can be developed under ultraviolet irradiation, and the printed image can be fully recognized.

In addition, as shown in Table 8, it was confirmed that if the ingots of Examples 1-8 to 1-12 were irradiated with ultraviolet light of a predetermined light intensity within a range of about 5000 μW / cm ² to 30,000 μW / cm ² , Then, the difference between the order values of the latent image area A and the non-latent image area B can be controlled to be 5 or more. In particular, it can be seen that when the wavelength region of ultraviolet light is 260 nm as in Example 1-10, when the light intensity is set to about 20,000 μW / cm ² , the order of the latent image region A relative to the non-latent image region B can be made. The difference in values becomes a maximum.

On the other hand, as in Comparative Example 1-1 as the ultraviolet light intensity of about 3000μW / cm ² of the case or, as Comparative Example 1-2 and Comparative Examples 1-3 as a light intensity of about 40000μW / cm ² or more of the case It is difficult to make the difference in the gradation value of the latent image area A with respect to the non-latent image area B be 5 or more, and it is impossible to sufficiently develop the latent image with good contrast.

In addition, as shown in Table 9, in Examples 1-13 and 1-14, the difference between the order values of the latent image area A and the non-latent image area B under the visible light irradiation of the plain ingot was 3.5 and 1 respectively. , The latent image cannot be confirmed visually. Furthermore, in the readability evaluation of the latent image GS1QR code, the latent image GS1QR code cannot be read. Thus, it was confirmed that the latent image water-based ink composition A can print a good latent image by using titanium oxide nano particles as a pigment. On the other hand, the difference between the order values of the other non-latent image regions C and the non-latent image regions B under the visible light irradiation of the plain ingot is 81.5 and 139.5, respectively, and the visible image can be fully identified by visual observation.

Next, as shown in Table 9, in the case where the ingots of Examples 1-13 and 1-14 were irradiated with ultraviolet rays having a wavelength of 320 nm, the printed materials were printed with the latent image water-based ink composition A. The ultraviolet rays irradiated in the latent image region A are absorbed, and as a result, the image is black in the ultraviolet camera. On the other hand, the ultraviolet rays irradiated in the non-latent image area B that was not printed with the latent image water-based ink composition A were reflected, and as a result, the photography was white in the ultraviolet camera. However, in Example 1-13, in the other non-latent image area C printed by using the water-based ink composition B of the visible image No. 3 in green, the visible image was latent imaged, and as a result, it was photographed in an ultraviolet camera. Is white and the visible image cannot be recognized. On the other hand, in Example 1-14, the ultraviolet rays irradiated in the other non-latent image area C printed by the aqueous ink composition A for visible images using carbon black were absorbed, and as a result, photographed in an ultraviolet camera It's black. In addition, in the readability evaluation of the latent image GS1QR code, the latent image GS1QR code can be read in both Examples 1-13 and 1-14. In particular, in Example 1-14, the latent image GS1QR code and the visible image were both visually recognized, but the information built into the latent image GS1QR code was also correctly represented. This also shows that in both of Examples 1-13 and 1-14, the latent image GS1QR code can be read correctly.

(Examples 2-1 to 2-7)

In Examples 2-1 to 2-7, as the latent image water-based ink, an ink composed of the aforementioned latent image water-based ink composition B was used. Other than that, after developing each latent image in the same manner as in Example 1-1, photography was performed using an ultraviolet camera. In addition, in each example, the wavelength of ultraviolet rays was changed to the values shown in Table 10 below, and the latent image area A under each wavelength of ultraviolet rays was calculated in the same manner as in Example 1-1. Difference in order value between non-latent image regions B. The results are shown in Table 10 below.

(Example 2-8)

In Example 2-8, compared with Example 1-13, the latent image water-based ink composition B was used instead of the latent image water-based ink composition A. Other than that, after developing each latent image in the same manner as in Example 1-13, photography was performed with an ultraviolet camera. In addition, in the same manner as in Example 1-13, the degree values of the latent image area A with respect to the non-latent image area B under the irradiation of ultraviolet rays with a wavelength of 320 nm were calculated, and other non-latent image areas C with respect to the non-latent image were calculated. The difference in the degree value of the region B. The results are shown in Table 11 below.

(Example 2-9)

In Example 2-9, compared with Example 2-8, the visible image water-based ink composition B was used instead of the visible image water-based ink composition A. Other than that, each latent image was developed in the same manner as in Example 2-8, and then photographed with an ultraviolet camera. In addition, in the same manner as in Example 2-8, the degree values of the latent image area A with respect to the non-latent image area B under the irradiation of ultraviolet rays with a wavelength of 320 nm and the other non-latent image areas C with respect to the non-latent image were calculated respectively. The difference in the degree value of the region B. The results are shown in Table 11 below.

(Visualization and readability of the developed latent image 2)

In Examples 2-1 to 2-7, the visibility of the developed latent image under ultraviolet irradiation was evaluated in the same manner as in the case of Example 1-1. In addition, the plain ingots before ultraviolet irradiation were also evaluated for visibility under visible light in the same manner as in the case of Example 1-1. The results are shown in Table 10.

In addition, in Examples 2-8 and 2-9, the visibility of a visible image and a developed latent image under ultraviolet irradiation was evaluated in the same manner as in the case of Example 1-1, respectively. In addition, with respect to the plain ingots before ultraviolet irradiation, the visibility of visible images under visible light was also evaluated in the same manner as in the case of Example 1-1. The results are shown in Table 11.

Furthermore, in Examples 2-8 and 2-9, the readability of the latent image GS1 QR code was also evaluated in the same manner as in the case of Example 1-1. The results are shown in Table 11.

(Result 2)

As shown in Table 10, the difference between the order value of the latent image area A and the non-latent image area B under the visible light irradiation of the plain ingot printed with the latent image is 1, and the latent image cannot be confirmed visually. From this, it was confirmed that the latent image aqueous ink composition B can print a good latent image by using zinc oxide nano particles as a pigment.

Next, as shown in Table 10, if the ingots of Examples 2-1 to 2-7 were irradiated with ultraviolet rays of a predetermined wavelength in the range of 260nm to 380nm, the water-based ink composition of the latent image was used. The ultraviolet rays irradiated in the latent image region A printed by B are absorbed, and as a result, the photograph is black in the ultraviolet camera. On the other hand, the ultraviolet light irradiated in the non-latent image area B printed without the latent image water-based ink composition B was reflected, and as a result, the photography was white in the ultraviolet camera. Furthermore, in each of Examples 2-1 to 2-7, the difference between the order value of the latent image area A and the non-latent image area B can be made 5 or more, and the latent image area A and the non-latent image area can be made. The contrast between B is sufficient to recognize the latent image. Accordingly, it was confirmed that in the printing using the water-based ink composition B of the latent image containing zinc oxide nano particles in the pigment, the latent image can be developed under ultraviolet irradiation, and the printed image can be fully recognized.

In addition, as shown in Table 11, in Examples 2-8 and 2-9, the difference between the order values of the latent image area A and the non-latent image area B under the visible light irradiation of the ingot was 0.5 and 4 respectively. , The latent image cannot be confirmed visually. Furthermore, in the readability evaluation of the latent image GS1QR code, the latent image GS1QR code cannot be read. From this, it was confirmed that the latent image aqueous ink composition B can print a good latent image by using zinc oxide nano particles as a pigment. On the other hand, the difference between the order values of the other non-latent image areas C and the non-latent image areas B under the visible light irradiation of the plain ingots is 81.5 and 133, respectively, and the visible images can be fully identified by visual observation.

Next, as shown in Table 11, when the ultraviolet ray with a wavelength of 320 nm was irradiated to the ingots of Examples 2-8 and 2-9, the latent image was printed by the latent image water-based ink composition B. The ultraviolet rays irradiated in the shadow area A are absorbed, and as a result, the image is black in the ultraviolet camera. On the other hand, the ultraviolet rays irradiated in the non-latent image region B that was not printed with the latent image water-based ink composition B were reflected, and as a result, the photograph was white in the ultraviolet camera. However, in Example 2-8, in the other non-latent image area C printed by using the water-based ink composition B of the visible image of green No. 3, the visible image was latent imaged, and as a result, it was photographed in an ultraviolet camera. Is white and the visible image cannot be recognized. On the other hand, in Example 2-9, the ultraviolet rays irradiated in the other non-latent image region C printed by the aqueous ink composition A for visible images using carbon black were absorbed, and as a result, photographed in an ultraviolet camera It's black. In addition, in the readability evaluation of the latent image GS1QR code, the latent image GS1QR code can be read in both Examples 2-8 and 2-9. In particular, in Example 2-9, the latent image GS1QR code and the visible image were both visually recognized, but the information built into the latent image GS1QR code was also correctly represented. This also shows that in both Examples 2-8 and 2-9, the latent image GS1 QR code can be read correctly.

(Example 3-1)

Using the latent image water-based ink composed of the latent image water-based ink composition A described above, a plain tablet (manufactured by Nissho Kyoto Pharmaceutical Industry Co., Ltd.) was marketed by an inkjet recording method, and its trade name was Placebo tablet. )) Printing of latent images. Printing is performed on only one side of the plain ingot, and is performed in one pass using an inkjet printer (KC 600dpi printing fixture equipped with a print head). The printing conditions were such that the mass of each droplet was 7 ng, and the amount of droplets was 7 pl. After printing, the printed image surface was dried by natural drying for 24 hours.

Secondly, in the indoor environment irradiated with a fluorescent lamp, the plain ingot printed with the latent image is irradiated with ultraviolet rays having a wavelength of 260 nm to 400 nm to develop the latent image (developing step), and then the developed latent image is recognized. Evaluation (inspection procedure). As the irradiation mechanism, a xenon light source (trade name: MAX-303) manufactured by Nissho Asahi Kogyo Co., Ltd. was used. The light intensity of the light source of the irradiation mechanism is set to about 100,000 μW / cm ² . In addition, the recognizability of the latent image is set to ○ when the latent image can be read in an indoor environment, and X when it cannot be read. The results are shown in Table 12 below.

(Example 3-2)

In this example, compared with Example 3-1, the latent image water-based ink composition A was changed to a latent image water-based ink composition B. Other than that, evaluation of the recognizability of the latent image printed on the surface of the plain ingot was performed in the same manner as in Example 3-1. The results are shown in Table 12 below.

(Result 3)

As shown in Table 12, the latent images printed on the plain ingots of each of the examples could not be recognized under the indoor environment illuminated by fluorescent lamps. Furthermore, if the plain ingot is irradiated with ultraviolet rays in an indoor environment, the latent image in the latent image area A printed on the plain ingots of each example is absorbed, and as a result, a black printed image can be visually confirmed. . On the other hand, it was confirmed that in the non-latent image region B in which the latent image is not printed, fluorescent light in a visible light region was generated using the irradiated ultraviolet rays as excitation light. Accordingly, it was confirmed that the latent image printed on the ladle image using the latent image aqueous ink composition A containing titanium oxide nano particles or the latent image aqueous ink composition B containing zinc oxide nano particles was not required. A latent image can be easily identified in a normal indoor environment irradiated with visible light by using a photographing device such as an ultraviolet camera.

Claims (20)

A latent image printed matter of a solid preparation, at least a part of a surface of the solid preparation is provided with a latent image; and the latent image printed matter of the solid preparation has at least: a latent image region, and an absorption wavelength region is in a range of 200 nm to 400 nm A latent image ink layer formed of the aforementioned latent image; and a non-latent image region reflecting at least the ultraviolet rays of the aforementioned wavelength region; the aforementioned latent image region when the latent image region and the non-latent image region are irradiated with visible light The difference between the order value with respect to the aforementioned non-latent image area is less than 5; when the aforementioned latent image area and the aforementioned non-latent image area are irradiated with light including at least the aforementioned wavelength region of ultraviolet light, the aforementioned latent image area is relative to the aforementioned non-latent image area. The difference in the order value of the latent image area is 5 or more. The latent image printed matter of the solid preparation according to claim 1, wherein the aforementioned surface is further provided with other non-latent image areas where a visible image is formed by absorbing the visible ink layer of the visible light; the aforementioned non-latent image areas and In a case where the other non-latent image area irradiates the visible light, the difference between the order values of the other non-latent image area and the non-latent image area is 5 or more. The latent image printed matter of the solid preparation according to claim 2, wherein the visible ink layer is a layer that transmits or reflects ultraviolet rays in the aforementioned wavelength region; and irradiates the non-latent image region and the other non-latent image region including the aforementioned wavelength region In the case of ultraviolet light, the difference between the order values of the other non-latent image areas and the non-latent image areas is less than 5. The latent image printed matter of the solid preparation according to claim 1, wherein the latent image ink layer contains at least titanium oxide particles and / or zinc oxide particles as a pigment. The latent image printed matter of the solid preparation according to claim 1, wherein the latent image ink layer is light-transmissive or light-reflective to the visible light. A method for photographing a latent image printed matter of a solid preparation, wherein the solid preparation is provided with a latent image on at least a part of the surface; the solid preparation has at least: a latent image area, and an ultraviolet ray with an absorption wavelength range of 200 nm or more and less than 400 nm is set; The latent image ink layer is formed with the latent image by the latent image ink layer; and the non-latent image region reflects at least the ultraviolet rays in the wavelength region; and the visible light is irradiated to the latent image region and the non-latent image region. When the difference between the order value of the latent image area and the non-latent image area is less than 5, when the latent image area and the non-latent image area are irradiated with light including ultraviolet light of the wavelength range, the latent image The difference between the degree value of the area with respect to the non-latent image area is 5 or more; the method for photographing the latent image printed matter of the solid preparation includes a developing step, irradiating the latent image area and the non-latent image area with at least the aforementioned wavelength The ultraviolet irradiation light in the area to develop the latent image in the latent image area; and a photographing step for receiving the irradiated light in Reflecting said reflected light of the non-latent image areas, while the development of the latent image area and the non-latent image areas in the developing step photographed. The method for photographing the latent image printed matter of the solid preparation according to claim 6, wherein the developing step is a step of using only ultraviolet rays having a wavelength range of 200 nm or more and less than 400 nm as the irradiation light. The method for photographing the latent image printed matter of the solid preparation according to claim 6, wherein the wavelength region of the ultraviolet light included in the irradiation light in the development step and the wavelength region of the reflected light received in the photography step At least part of it overlaps. The method for photographing the latent image printed matter of the solid preparation according to claim 6, wherein the solid preparation further has another non-latent image area in which a visible image is formed by absorbing the visible ink layer of the visible light; When the area and the aforementioned other non-latent image areas are irradiated with visible light, the difference between the order value of the aforementioned other non-latent image areas relative to the aforementioned non-latent image areas is 5 or more; the aforementioned photographing steps are also performed on the aforementioned other non-latent image areas. Steps in photography. The method for photographing the latent image printed matter of the solid preparation according to claim 9, wherein the visible ink layer is a layer that transmits or reflects ultraviolet rays in the wavelength region; irradiating the non-latent image region and the other non-latent image regions includes In the case of the ultraviolet light in the aforementioned wavelength region, the difference between the order values of the other non-latent image regions and the aforementioned non-latent image regions is less than 5; the development step is performed by also irradiating the other non-latent image regions And a step of latentizing the visible image of the other non-latent image area including at least the ultraviolet light in the aforementioned wavelength region; the aforementioned photographing step is also performed on the other non-latent image area of the latent image in the developing step. Steps for photography. The method for photographing a latent image print of a solid preparation according to claim 6, wherein the latent image ink layer contains at least titanium oxide particles and / or zinc oxide particles as pigments as the solid preparation. The method for photographing a latent image printed matter of the solid preparation according to claim 6, wherein the latent image ink layer has light transmittance or light reflectivity to visible light. A method for inspecting an edible substance, wherein the edible substance is provided with a latent image on at least a part of the surface; the edible substance has at least: a latent image region that absorbs ultraviolet rays in a wavelength range of 200 nm or more and less than 400 nm; The latent image ink layer is formed with the aforementioned latent image; the non-latent image region emits fluorescent light in the visible light region by irradiation of ultraviolet rays in the aforementioned wavelength region; and other non-latent image regions, which absorb visible light and form the aforementioned wavelength A visible image is formed by the visible ink layer transmitted or reflected by the ultraviolet rays of the area; when the latent image area and the non-latent image area are irradiated with visible light, the degree value of the latent image area relative to the non-latent image area is The difference is less than 5, when the latent image area and the non-latent image area are irradiated with ultraviolet light including the wavelength range, the difference between the order value of the latent image area and the non-latent image area is 5 or more. When the aforementioned non-latent image area and the other non-latent image area are irradiated with visible light, the order of the aforementioned other non-latent image area relative to the aforementioned non-latent image area The difference between the values is 5 or more. When the non-latent image area and the other non-latent image area are irradiated with light including ultraviolet rays of the aforementioned wavelength range, the order value of the other non-latent image area relative to the non-latent image area. The difference is less than 5; the inspection method of the aforementioned edibles includes a developing step, by irradiating the latent image region and the non-latent image region with irradiation light including at least the ultraviolet rays of the wavelength region, and applying the non-latent image to the non-latent image. The area generates the aforementioned fluorescence, and the latent image ink layer in the aforementioned latent image region absorbs the aforementioned ultraviolet rays, thereby developing the aforementioned latent image in the aforementioned latent image region; and an inspection step for visually or by using a light receiving wavelength as a visible light region. The photography mechanism inspects the latent image developed in the developing step, and inspects the latent image. The developing step is also to irradiate the other non-latent image region with ultraviolet light including at least the wavelength region of the wavelength, so that the aforementioned Steps for latent image formation of visible images in other non-latent image areas; the aforementioned inspection steps are performed visually or by the aforementioned photography agency and The non-latent image area and the other non-latent image areas developed in the aforementioned developing step are photographed and inspected. The edible matter inspection method according to claim 13, wherein the developing step is a step of using only ultraviolet rays having a wavelength range of 200 nm or more and less than 400 nm as the irradiation light. The edible matter inspection method according to claim 13, wherein the latent image ink layer of the edible matter contains at least titanium oxide particles and / or zinc oxide particles as a pigment. The method for inspecting an edible substance according to claim 13, wherein the latent image ink layer of the edible substance is a coating film made of a water-based ink before or after drying. The edible matter inspection method according to claim 13, wherein the latent image ink layer of the edible matter has light transmittance to visible light. The edible matter inspection method according to claim 13, wherein the wavelength of the ultraviolet rays contained in the irradiation light of the development step and the wavelength of the ultraviolet rays absorbed in the latent image ink layer at least partially overlap. A latent image printed matter of a solid preparation, at least a part of a surface of the solid preparation is provided with a latent image; and the latent image printed matter of the solid preparation has at least: a latent image region, and an absorption wavelength region is in a range of 200 nm to 400 nm The latent image ink layer of the ultraviolet ray forms the aforementioned latent image; the non-latent image region reflects at least the ultraviolet ray in the wavelength region and / or emits fluorescence; and other non-latent image regions absorb visible light and form the aforementioned wavelength A visible image is formed by the visible ink layer transmitted or reflected by the ultraviolet rays in the area; when the latent image area and the non-latent image area are irradiated with the visible light, the order value of the latent image area relative to the non-latent image area The difference is less than 5; when the latent image area and the non-latent image area are irradiated with at least the ultraviolet light of the wavelength range, the difference between the order value of the latent image area and the non-latent image area is 5 The above; when the aforementioned non-latent image area and the aforementioned other non-latent image area are irradiated with the aforementioned visible light, the aforementioned other non-latent image area is relatively The difference between the order values of the non-latent image area is 5 or more; when the non-latent image area and the other non-latent image area are irradiated with light including ultraviolet rays of the wavelength range, the other non-latent image area is relative to the foregoing. The difference in the order value of the non-latent image area is less than 5. A method for photographing a latent image printed matter of a solid preparation, wherein the solid preparation is provided with a latent image on at least a part of the surface; the solid preparation has at least: a latent image area, and an ultraviolet ray with an absorption wavelength range of 200 nm to 400 nm is set; The latent image ink layer forms the aforementioned latent image by the aforementioned latent image ink layer; the non-latent image region reflects at least the ultraviolet rays in the aforementioned wavelength region and / or emits fluorescence; and other non-latent image regions are absorbed by Visible light forms a visible image by forming a visible ink layer that transmits or reflects ultraviolet light in the aforementioned wavelength region; when the aforementioned latent image region and the non-latent image region are irradiated with visible light, the aforementioned latent image region is relative to the aforementioned non-latent image The difference between the order values of the regions is less than 5. When the latent image area and the non-latent image area are irradiated with light including ultraviolet rays of the aforementioned wavelength range, the order value of the latent image area relative to the non-latent image area The difference is 5 or more. When the non-latent image area and the other non-latent image area are irradiated with visible light, the other non-latent image areas are relatively When the difference between the order values of the non-latent image area is 5 or more, when the non-latent image area and the other non-latent image area are irradiated with light including ultraviolet rays of the wavelength range, the other non-latent image area is relative to The difference in the order value of the non-latent image area is less than 5; the method for photographing the latent image printed matter of the solid preparation includes a developing step, irradiating the latent image area and the non-latent image area with ultraviolet rays including at least the wavelength range. Irradiated light to develop the latent image in the latent image area; and a photographing step to receive the reflected light reflected by the irradiated light in the non-latent image area and / or fluorescent light generated in the non-latent image area And photographing the latent image area and the non-latent image area developed in the developing step; the developing step is to irradiate the other non-latent image area with ultraviolet light including at least the wavelength region of the wavelength And the step of latentizing the visible images of the other non-latent image areas; the aforementioned photographing steps are also performed on the other non-latent image areas and on the aforementioned display Step photographic latent image of the latent image area of the other non-step.