WO2018116645A1

WO2018116645A1 - Inkjet aqueous ink composition, method for inhibiting fading of printed image on solid preparation, and solid preparation

Info

Publication number: WO2018116645A1
Application number: PCT/JP2017/039419
Authority: WO
Inventors: 悠人榎本; 聡一郎森川
Original assignee: 株式会社Ｓｃｒｅｅｎホールディングス
Priority date: 2016-12-20
Filing date: 2017-10-31
Publication date: 2018-06-28
Also published as: JP2018100336A; CN110088212A; CN110088212B; JP6389506B2

Abstract

Provided are: an inkjet aqueous ink composition with which it is possible to inhibit fading and discoloration of printed images on the surfaces of solid preparations such as medicine or food; a method of inhibiting fading of printed images on solid preparations; and a solid preparation. This inkjet aqueous ink composition is used for printing on solid preparations, and is characterized in that: the aqueous ink composition comprises an edible dye and a fading inhibitor; the dye includes at least one specific dye selected from the group consisting of Red No. 2, Red No. 4, Red No. 40, Red No. 102, Yellow No. 4, Yellow No. 5, Green No. 3, Blue No. 1, and sodium copper chlorophyllin, and another dye as an optional component; the fading inhibitor is at least one selected from the group consisting of monosaccharides, disaccharides, dextrins, and sugar alcohols; and the content of the fading inhibitor with respect to the total mass of the aqueous ink composition is 50% by mass or less.

Description

Aqueous ink composition for inkjet, method for suppressing discoloration of printed image of solid preparation, and solid preparation

The present invention relates to a water-based ink composition for inkjet, a method for suppressing discoloration of a printed image of a solid preparation, and a solid preparation, and more specifically, suppresses discoloration and discoloration of a printed image formed on the surface of a solid preparation such as pharmaceuticals and foods. The present invention relates to a water-based ink composition for inkjet, a method for suppressing discoloration of a printed image of a solid preparation, and a solid preparation.

Ink jet inks for tablets and capsules are roughly classified into pigment inks in which pigments are dispersed and dye inks using dyes. In general, dye ink is easy to penetrate into tablets and the like, and has an advantage that the dye is fixed to the inside. On the other hand, since the pigment ink has a low penetrating ability, the pigment ink can penetrate into the inner part of the uncoated tablet whose surface is not coated. However, when printing on tablets with few pores on the surface, such as sugar-coated tablets and film-coated tablets (FC tablets), it is difficult for the pigment ink to penetrate inside. For this reason, for example, when a printed image is scratched or scraped off due to scratching or the like, the pigment fixed on the surface of a tablet or the like is also scraped off, resulting in a decrease in print quality due to transfer or color loss of the printed image. Invite you.

Therefore, for tablets such as sugar-coated tablets and FC tablets, printing with dye ink is advantageous from the viewpoint of ink fixability. However, in order to print on tablets or the like, the dye ink needs to be composed of raw materials that meet the standards stipulated in the Pharmaceutical Affairs Law. Therefore, it is necessary to develop a dye ink from limited materials. For example, in the case of a black dye ink, the dye ink is prepared by mixing red, yellow, and blue dyes.

However, there is a problem that the printed image turns green (green) when left on for a certain period of time after printing on a sugar-coated tablet using black dye ink. In addition, when a red azo dye is used as a constituent component of the black dye, there is a problem that due to photolysis of the azo dye, the saturation of the printed image decreases with time and the light fades.

JP 2016-236279 A

The present invention has been made in view of the above problems, and its purpose is to provide a water-based inkjet ink composition capable of suppressing discoloration and discoloration of a printed image on the surface of a solid preparation such as pharmaceuticals and foods, and a solid preparation. It is providing the discoloration suppression method and solid formulation of a printed image.

The inventor of the present application has found that one of the causes of fading and discoloration in images printed on the surface of a solid preparation is due to humidity.
That is, it was confirmed that a certain dye has higher penetrability to a solid preparation than other dyes under a certain humidity even after printing. Therefore, for example, when printing on the surface of a solid preparation in a single color using only that specific dye, the color penetrates into the solid preparation as time passes, resulting in a decrease in the saturation of the printed image and generation of a fading. In addition, when printing on the surface of a solid preparation with a dye ink mixed with another dye, the specific dye is more permeable to the solid preparation than the other dye, so the two are separated and only the other dye is solid. It remains on the surface of the preparation. As a result, the print image is represented only by other dyes, and a discoloration of the print image occurs.

An aqueous inkjet ink composition according to the present invention is an aqueous inkjet ink composition used for printing on a solid preparation in order to solve the above-described problem, and includes an edible dye and a fading inhibitor. And the dye is at least one selected from the group consisting of Red No. 2, Red No. 4, Red No. 40, Red No. 102, Yellow No. 4, Yellow No. 5, Green No. 3, Blue No. 1 and copper chlorophyllin sodium. The discoloration inhibitor is at least one selected from the group consisting of monosaccharides, disaccharides, dextrins and sugar alcohols, and The content of the discoloration inhibitor is 50% by mass or less based on the total mass of the water-based ink composition.

In the above configuration, the specific dye such as Red No. 2 has a property of penetrating into the solid preparation over time due to humidity. On the other hand, monosaccharides, disaccharides, dextrins and sugar alcohols exhibit a function of suppressing penetration of the specific dyes into the solid preparation caused by humidity in the printed image. Therefore, in an image printed using only a specific dye, it is possible to suppress a decrease in saturation due to penetration of the specific dye into the solid preparation and reduce the occurrence of fading. In addition, in an image printed using a mixed dye of a specific dye and another dye, the printed image is discolored as a result of preventing the specific dye from separating into the other dye and penetrating into the solid preparation. Can be reduced.

In addition, azo dyes such as Red No. 2, Red No. 40, and Red No. 102 contained in the specific dye have the property of decomposing (photodecomposing) by light irradiation, so that the printed image is light. May fade. However, the fading inhibitor also exhibits a function of suppressing photodegradation with respect to such a specific dye. Therefore, in the water-based ink composition having the above-described configuration, it is possible to reduce the deterioration of the printed image due to the occurrence of light fading.

In addition, in the said structure, the said fading inhibitor can fully melt | dissolve in an aqueous ink composition by making content of a fading inhibitor 50 mass% or less with respect to the total mass of an aqueous ink composition. It is possible to prevent the precipitation.

In the above configuration, the monosaccharide is preferably at least one of galactose and fructose.

In the above configuration, the disaccharide is preferably at least one of maltose and trehalose.

In the above configuration, the dextrins are preferably cyclodextrins.

In the above configuration, the sugar alcohol is preferably at least one selected from the group consisting of reduced isomaltulose, xylitol, and sorbitol.

Moreover, in order to solve the above-mentioned problem, the method for suppressing discoloration of a printed image of a solid preparation according to the present invention includes a edible dye, a discoloration inhibitor, and a discoloration suppressing method for a printed image printed on a solid preparation. An aqueous ink composition for inkjet, wherein the dye is red No. 2, red No. 4, red No. 40, red No. 102, yellow No. 4, yellow No. 5, green No. 3, blue No. 1 and copper chlorophyllin sodium Comprising at least one specific dye selected from the group consisting of, and other dyes as optional components, wherein the antifading agent is selected from the group consisting of monosaccharides, disaccharides, dextrins and sugar alcohols An ink-jet aqueous ink composition, wherein the content of the discoloration inhibitor is 50% by mass or less based on the total mass of the water-based ink composition. A preparation step of preparing a water-based ink, a printing step of printing on the surface of the solid preparation by an inkjet method using the water-based ink for ink-jet to form the print image, and a fading inhibitor in the print image, A discoloration suppressing step for suppressing penetration of the dye into the solid preparation.

In the above-described configuration, an ink-jet aqueous ink is prepared that includes a water-based ink composition containing a fading inhibitor such as a monosaccharide (preparation step), and further, the surface of the solid preparation by the ink-jet method using the water-based ink Printing is performed (printing process). Furthermore, the discoloration inhibitor in the printed image suppresses penetration into the solid preparation caused by the humidity of the specific dye (fading suppression step). Thereby, when the dye in a water-based ink composition is only a specific dye, generation | occurrence | production of the fading by penetration | invasion to the solid formulation of a specific dye can be reduced. In addition, when a dye other than the specific dye is included as the dye in the aqueous ink composition, the specific dye is prevented from separating from the other dye and penetrating into the solid preparation, and the printed image is discolored. Can be reduced. That is, with the above-described method, discoloration and discoloration of a printed image printed on a solid preparation by an inkjet method can be suppressed, and deterioration of the visibility of the printed image with a change with time can be reduced. As a result, for example, even when product information is printed, dispensing errors, accidental ingestion, and the like can be prevented.

In the above-described configuration, the discoloration suppressing step is based on the printed image in the solid preparation immediately after the printing step, and the printed image in the solid preparation after being stored for 24 hours in an atmosphere at a temperature of 25 ° C. and a relative humidity of 60%. The Δa ^* of the L ^* a ^* b ^* color system conforming to JIS Z 8730 is set to −18 or more. With the above configuration, discoloration of the print image due to humidity can be suppressed, and the visibility of the print image can be maintained at a good level.

In the above-described configuration, the fading inhibiting agent in the printed image may further include a photofading inhibiting step for inhibiting the photodecomposition of the specific dye. With the above-described configuration, it is possible to suppress the light fading of the printed image due to the photodecomposition of the specific dye and maintain the visibility of the printed image.

Furthermore, in the above-described configuration, the light fading suppression step is based on the printed image in the solid preparation immediately after the printing step, and the JIS of the printed image in the solid preparation after irradiation with visible light having an integrated light amount of 1.2 million lux. The color difference ΔE * (ab) of the L * a * b * color system conforming to Z 8781 is set to 17 or less.

In the above configuration, the dextrins are preferably cyclodextrins.

Further, in order to solve the above-mentioned problems, the solid preparation according to the present invention is a solid preparation having a dry film of an aqueous inkjet ink on the surface, and the aqueous inkjet ink comprises the aqueous ink composition described above. It is what is included.

According to the above configuration, the discoloration inhibitor is contained in the dry film of the ink-jet ink, and the discoloration inhibitor suppresses penetration of the specific dye due to humidity into the solid preparation as described above. be able to. Therefore, when the dye in the water-based ink composition is only a specific dye, it is possible to reduce the occurrence of fading of the printed image formed by the dry film. In addition, when the dye in the water-based ink composition contains other dyes in addition to the specific dye, the specific dye is separated from the other dyes and prevented from penetrating into the solid preparation, and the printed image is discolored. Can be reduced. Furthermore, since the fading inhibitor also suppresses the photodegradation of the specific dye by light irradiation, it is possible to reduce the occurrence of light fading in the printed image formed by the dry film. That is, when the solid preparation has the above-described configuration, it is possible to reduce discoloration (including light discoloration) and discoloration of the printed image formed by the dry film, and to suppress deterioration of the visibility of the printed image with time. be able to. As a result, it is possible to provide a solid preparation capable of preventing dispensing errors and accidental ingestion.

According to the present invention, the discoloration inhibitor composed of monosaccharides, disaccharides, dextrins and sugar alcohols can suppress the penetration into the solid preparation caused by the humidity by the specific dye such as Red No. 2. Therefore, it is possible to reduce discoloration or discoloration of the image printed on the solid preparation surface over time due to humidity. Further, it is possible to reduce the occurrence of light fading of the printed image due to light irradiation.

That is, according to the present invention, an ink jet capable of suppressing discoloration (including light discoloration) and discoloration of a printed image in a solid preparation such as a pharmaceutical or food, and improving the moisture resistance and light resistance of the printed image. Water-based ink composition, method for suppressing discoloration of printed image of solid preparation, and solid preparation can be provided.

(Water-based ink composition for inkjet)
The ink-jet aqueous ink composition (hereinafter referred to as “water-based ink composition”) according to the present embodiment will be described below.

The water-based ink composition of the present embodiment is a water-based ink containing at least an edible dye and a fading inhibitor and having a main solvent of water. In addition, the water-based ink composition of the present embodiment may be made edible by using a material that complies with the standards of pharmaceutical additives, Japanese Pharmacopoeia, or Food Additives Standards specified by the Pharmaceutical Affairs Law. And can be suitably used for inkjet recording. Inkjet recording means a system in which an aqueous ink composition is ejected as droplets from a fine inkjet head, the droplets are fixed on a recording medium, and an image is formed.

The “edible property” of the dye means a substance that is approved for oral administration as a pharmaceutical or a pharmaceutical additive and / or a food or a food additive.

The dye is at least one specific selected from the group consisting of Red No. 2, Red No. 4, Red No. 40, Red No. 102, Yellow No. 4, Yellow No. 5, Green No. 3, Blue No. 1 and copper chlorophyllin sodium. Contains dye. Moreover, the said dye may contain another dye as needed other than a specific dye. Other dyes are not particularly limited as long as they have edible properties. Specific examples include xanthene dyes such as Red No. 3, Red No. 104, Red No. 105, and Red No. 106, and indigoid dyes such as Blue No. 2. In addition, edible natural pigments such as cochineal pigments, cacao pigments, and caramel pigments can also be used as other dyes.

When the dye is only a specific dye, the content of the dye (specific dye) is preferably in the range of 0.5% by mass to 12% by mass with respect to the total mass of the aqueous ink composition. More preferably, it is within the range of 5% to 5% by mass. When the content of the specific dye is 0.5% by mass or more, it is possible to prevent the density of the printed image from becoming insufficient with many dyes. On the other hand, when the content of the specific dye is 12% by mass or less, it is possible to prevent the dye component from being deposited in the nozzle of the inkjet head.

In addition, when the dye contains another dye, the content of the other dye can be appropriately set according to the type thereof.

The discoloration inhibitor has a function of inhibiting the specific dye contained in the printed image from penetrating into the solid preparation with time change due to humidity. Therefore, when other dye is contained in the dye, the specific dye can be prevented from being separated from the other dye. Thereby, generation | occurrence | production of the fading and discoloration of a printed image can be reduced, and the visibility of a printed image can be maintained favorable. The fading inhibitor also has a function of suppressing the specific dye from photodegradation by light irradiation such as natural light. Among the specific dyes, for example, azo dyes such as Red No. 2, Red No. 40 and Red No. 102 may be photodegraded by light irradiation, resulting in photo-fading of the printed image. However, the color fading inhibitor also suppresses the photodecomposition of such a specific dye, so that the occurrence of photofading in the printed image can be reduced.

In addition, “amber” means that the saturation of the printed image is irreversibly lowered as a result of the penetration of the specific dye into the solid preparation due to humidity. In addition, “discoloration” means that the specific dye penetrates into the solid preparation due to humidity and the specific dye and other dyes are separated. As a result, the hue of the other dye is superior to that of the specific dye, and the entire printed image This means that the hue as irreversibly changes. “Light fading” means that the dye contained in the printed image is photodegraded due to the influence of natural light or the like, and thereby the color tone of the printed image is irreversibly changed or the printed image is deteriorated.

The discoloration inhibitor is at least one selected from the group consisting of monosaccharides, disaccharides, dextrins and sugar alcohols.

The monosaccharide is not particularly limited, and examples thereof include glucose, galactose, mannose, and fructose. Of these, galactose and fructose are preferred in the present invention.

The disaccharide is not particularly limited, and examples thereof include sucrose (sucrose, sugar), lactose (lactose), maltose, trehalose, palatinose (isomaltulose), and the like. Of these, maltose and trehalose are preferred in the present invention.

The dextrins are not particularly limited, and examples thereof include cyclodextrins. The cyclodextrin is not particularly limited, and examples thereof include α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and δ-cyclodextrin.

The sugar alcohols are not particularly limited, and examples thereof include mannitol, erythritol, reduced isomaltulose, xylitol, sorbitol and the like. Furthermore, the reduced isomaltulose is a compound obtained by reducing isomaltulose by hydrogenation or the like. Reduced isomaltulose includes α-D-glucopyranosyl-1,1-mannitol (hereinafter referred to as “GPM”) and α-D-glucopyranosyl-1,6-sorbitol (hereinafter referred to as “GPS-6”). And a mixture. The mixing ratio of GPM and GPS-6 is not particularly limited, but they are usually mixed in approximately equimolar amounts. Of the sugar alcohols, reduced isomaltulose, xylitol and sorbitol are preferred in the present invention.

Each of the above-mentioned fading inhibitors exemplified above can be used alone or in combination of two or more.

The content of the fading inhibitor is 50% by mass or less, preferably 1% by mass to 15% by mass, more preferably 5% by mass to 10% by mass with respect to the total mass of the aqueous ink composition. In particular, when dextrins or sugar alcohols are used as the discoloration inhibitor, their content is preferably 20% by mass or less, preferably 1% by mass to 15% by mass with respect to the total mass of the aqueous ink composition. More preferably, the content is 3% by mass to 8% by mass. By setting the content of the fading inhibitor to 50% by mass or less, it is possible to prevent the fading inhibitor from being precipitated in the aqueous ink composition.

The water-based ink composition of the present embodiment contains water (water as a main solvent). As the water, it is preferable to use water from which ionic impurities such as ion-exchanged water, ultrafiltered water, reverse osmosis water, distilled water, or ultrapure water have been removed. In particular, water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be prevented over a long period of time. Moreover, it does not specifically limit as content of water, It can set suitably as needed.

In addition, in the water-based ink composition of the present embodiment, other additives are blended as long as they meet the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law. Also good. Examples of the additive include a surface tension adjusting agent, a wetting agent, a water-soluble resin, an organic amine, a surfactant, a pH adjusting agent, a chelating agent, an antiseptic, a viscosity adjusting agent, and an antifoaming agent. Except for the surface tension adjusting agent and the wetting agent, the content of these additives is not particularly limited, and can be set as appropriate (the contents of the surface tension adjusting agent and the wetting agent will be described later). .)

The surface tension adjusting agent is not particularly limited as long as it conforms to standards such as the Pharmaceutical Affairs Law, and specific examples include glycerin fatty acid esters. Examples of the glycerin fatty acid ester include caprylic acid decaglyceryl, lauric acid hexaglycerin ester, oleic acid hexaglycerin ester, condensed linolenic acid tetraglycerin ester, fatty acid ester palm palm, lauric acid decaglyceryl having an HLB of 15 or less, and HLB. Examples include decaglyceryl oleate of less than 13. You may use these individually by 1 type or in mixture of 2 or more types.

As the caprylic acid decaglyceryl, it is possible to use a commercially available product. Examples of such a commercially available product include Ryoto (registered trademark) polyglycerate CE19D (trade name, manufactured by Mitsubishi Chemical Foods Co., Ltd., HLB). Value 15), SY glister MCA750 (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 16), and the like.

The HLB value is an HLB value according to the Griffin method and means a value obtained by the following equation.
HLB value = 20 × (sum of formula weight of hydrophilic group / molecular weight)
The HLB value is a value in the range of 0 to 20. The larger the HLB value, the stronger the hydrophilicity, and the smaller the HLB value, the stronger the hydrophobicity.

As the decaglyceryl laurate, those having an HLB of 15 or less can be used. When the decaglyceryl laurate has an HLB of more than 15, the ejection stability is lowered, for example, the occurrence of fading due to clogging of the nozzles of the inkjet head. The lower limit of HLB is preferably 10 or more from the viewpoint of solubility in an aqueous solvent. Further, as decaglyceryl laurate having an HLB of 15 or less, a commercially available product can be used. Examples of such a commercially available product include NIKKOL (registered trademark) DECAGLYN 1-L (trade name, Nikko Chemicals ( HLB value 14.5), SY Glister ML-750 (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 14.8), and the like.

As the decaglyceryl oleate, those having an HLB of less than 13 can be used. When the HLB is 13 or more, the ejection stability is deteriorated, such as blurring due to clogging of the nozzles of the inkjet head. In addition, it is preferable that the minimum of HLB is 10 or more from a viewpoint of the solubility with respect to a water solvent. Further, as decaglyceryl oleate having an HLB of less than 13, a commercially available product can be used. Examples of such a commercially available product include NIKKOL (registered trademark) DECAGLYN 1-OV (trade name, Nikko Chemicals ( Co., Ltd., HLB value 12), SY Glister MO-7S (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 12.9), and the like.

As the lauric acid hexaglycerin ester, a commercially available product can be used, and as such a commercially available product, for example, NIKKOL (registered trademark) HEXAGLYN 1-L (trade name, manufactured by Nikko Chemicals Co., Ltd., HLB) Value 14.5), SY Glister ML-500 (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 13.5), and the like.

Commercially available products can be used as the oleic acid hexaglycerin ester. Examples of such commercially available products include SY Glyster MO-5S (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 11. 6) and the like.

Commercially available products can be used as the condensed linolenic acid tetraglycerin ester. Examples of such commercially available products include SY Glyster CR-310 (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd.). It is done.

As the fatty acid ester palm palm, a commercially available product can be used, and examples of such a commercially available product include Tirabazole W-01 (trade name, manufactured by Taiyo Kagaku Co., Ltd.).

The content of the surface tension adjusting agent is preferably in the range of 0.1% by mass to 10% by mass, and preferably in the range of 0.5% by mass to 5% by mass with respect to the total mass of the aqueous ink composition. More preferably. When the content of the surface tension adjusting agent is 0.1% by mass or more, when printing is performed by an inkjet method, ejection failure due to meniscus formation failure or the like at the nozzle in the inkjet head is prevented, and the nozzle is clogged. Can be prevented. As a result, the discharge stability can be improved. On the other hand, when the content of the surface tension adjusting agent is 10% by mass or less, it is possible to prevent an adverse effect on discharge due to insoluble matter or poor emulsification of the surface tension adjusting agent.

The wetting agent is not particularly limited as long as it conforms to standards such as the Pharmaceutical Affairs Law, and specific examples include propylene glycol and glycerin.

The amount of the wetting agent added is preferably 3% by mass to 50% by mass and more preferably 10% by mass to 40% by mass with respect to the total mass of the aqueous ink composition. By setting the content of the wetting agent to 3% by mass or more, clogging in the vicinity of the nozzle of the inkjet head can be prevented, and the ejection performance can be further improved. On the other hand, by setting the content of the wetting agent to 50% by mass or less, the viscosity of the aqueous ink composition can be appropriately controlled.

(Method for suppressing discoloration of printed image of solid preparation)
The method for suppressing discoloration of a printed image of a solid preparation of the present embodiment includes a preparation step of preparing an aqueous inkjet ink (hereinafter sometimes referred to as “aqueous ink”) containing the above-described aqueous ink composition, and an aqueous ink. And at least a discoloration suppressing step for suppressing discoloration of a printed image.

The water-based ink preparation step may include a water-based ink composition manufacturing step. In this case, the production process of the water-based ink composition can be performed by mixing the above-described components by an appropriate method. That is, a dye, a fading inhibitor, water and, if necessary, an additive are mixed and sufficiently stirred. Furthermore, if necessary, filtration is performed to remove coarse particles and foreign matters that cause clogging. Thereby, the water-based ink composition which concerns on this Embodiment can be obtained.

The mixing method of each material is not particularly limited, and for example, the materials can be sequentially added to a container equipped with a stirring device such as a mechanical stirrer or a magnetic stirrer to perform stirring and mixing. Moreover, it does not specifically limit as a filtration method, For example, centrifugal filtration, filter filtration, etc. are employable.

The printing step is a step of printing an image on the surface of a solid preparation by an ink jet method. More specifically, aqueous ink is ejected as ink droplets onto a solid preparation from a fine nozzle, and the ink droplets are adhered to the surface of the solid preparation. The discharge method is not particularly limited, and for example, a known method such as a continuous injection type (charge control type, spray type, etc.), an on-demand type (piezo type, thermal type, electrostatic suction type, etc.) can be employed. . Printing conditions such as ink droplet ejection amount and printing speed are not particularly limited, and can be set as necessary.

In addition, the printing process includes a drying process for drying ink droplets attached to the surface of the solid preparation. It does not specifically limit as a drying method, In addition to hot air drying, natural drying etc. can be performed. Also, drying conditions such as drying time and drying temperature are not particularly limited, and can be appropriately set according to the ejection amount of ink droplets, the type of the water-based ink composition, and the like.

The discoloration suppressing step is a step in which the discoloration inhibitor contained in the printed image suppresses the penetration of the specific dye due to humidity into the solid preparation. For example, when the solid preparation on which the image is printed is stored for 24 hours in an atmosphere of a temperature of 25 ° C. and a relative humidity of 60%, the discoloration suppressing step is based on the printed image immediately after printing, based on the L ^* a ^* b ^* Δa ^* ₁ in the color system is suppressed to −18 or more, preferably −10 to +10, more preferably −5 to +5. By setting Δa ^* ₁ to −18 or more, discoloration of the printed image can be reduced and good visibility can be maintained. As a result, even when product information or the like is printed on the surface of the solid preparation, misidentification of the product information can be prevented, and the occurrence of dispensing mistakes and accidental ingestion can be reduced. Note that the print image immediately after printing means a print image after drying.

The Δa ^* ₁ is based on JIS Z 8730 and is represented by the following general formula (1).
Δa ^* ₁ = a ^* ₁₋ a ^* ₀ (1)
(However, the a ^* ₀ represents a value in the L ^* a ^* b ^* color system of the printed image in the solid preparation immediately after the printing step, and the a ^* ₁ is an atmosphere at a temperature of 25 ° C. and a relative humidity of 60%. (The L ^* a ^* b ^* color system value of the printed image in the solid preparation after 24 hours storage is shown.)
The L ^* a ^* b ^* color system is a color space recommended by the International Commission on Illumination (CIE) in 1976, and is a color space called the CIE 1976 (L ^* a ^* b ^* ) color system. In Japanese Industrial Standard, it is defined in JIS Z 8730.

In the present embodiment, a light fading suppressing step for suppressing the photodecomposition of the specific dye may be further included. As described above, the fading inhibitor has a function of suppressing the photodegradation of a specific dye such as an azo dye, so that the photofading of the printed image can be reduced.

For example, when the printed image on the surface of the solid preparation is irradiated with visible light having a cumulative light amount of 1.2 million lux (wavelength range: 380 nm to 750 nm), the light fading suppression step is performed using L ^* a ^{* based on} the printed image immediately after printing ^. ΔE ^* (ab) in the b ^* color system can be suppressed to 17 or less, preferably 0 to 10, more preferably 0 to 5. By setting ΔE ^* (ab) to 17 or less, light fading of a printed image can be reduced and good visibility can be maintained. As a result, even when product information or the like is printed on the surface of the solid preparation, misidentification of the product information can be prevented, and the occurrence of dispensing mistakes and accidental ingestion can be reduced. Note that the print image immediately after printing means a print image after drying, as described above.

The ΔE ^* (ab) is based on JIS Z8781, and is represented by the following general formula (2).
ΔE ^* (ab) = ((ΔL ^* ₂ ) ² + (Δa ^* ₂ ) ² + (Δb ^* ₂ ) ² ) ^1/2 (2)
However, ΔL ^* ₂ , Δa ^* _2, and Δb ^* ₂ are respectively expressed as follows.
ΔL ^* ₂ = L ^* _2- L ^* ₀
(L ^* ₀ represents the lightness of the L ^* a ^* b ^* color system immediately after the printing step in the printed image of the solid preparation, and L ^* ₂ represents visible light with an integrated light amount of 1.2 million lux in the printed image of the solid preparation. Represents the brightness of the L ^* a ^* b ^* color system after irradiation.)
Δa ^* ₂ = a ^* _2- a ^* ₀
(The a ^* ₀ represents the value of the L ^* a ^* b ^* color system immediately after the printing process in the printed image of the solid preparation, and the a ^* ₂ is a visible light amount of 1.2 million lux in the printed image of the solid preparation. (L ^* a ^* b ^* color system values after light irradiation are shown.)
Δb ^* ₂ = b ^* _2- b ^* ₀
(B ^* ₀ represents the value of the L ^* a ^* b ^* color system immediately after the printing process in the printed image of the solid preparation, and b ^* ₂ represents visible light having an integrated light amount of 1,200,000 lux in the printed image of the solid preparation. Represents the value of the L ^* a ^* b ^* color system after irradiating

(Solid preparation)
In the present specification, “solid preparation” means food preparations and pharmaceutical preparations. Examples of solid preparation forms include OD tablets (orally disintegrating tablets), plain tablets, FC (film coat) tablets, and sugar-coated tablets. And tablets or capsules. The solid preparation may be used for pharmaceuticals or food. Examples of tablets for food use include health foods such as tablet confectionery and supplements.

On the surface of the solid preparation, a print image composed of a dry film directly formed by an ink jet recording method using an aqueous ink containing the aqueous ink composition is formed. And a dry film is comprised at least by the dye contained in the water-based ink composition, and the fading inhibitor.

As described above, the anti-fading agent suppresses penetration of a specific dye into a solid preparation due to ambient humidity. This effect is particularly effective when the solid preparation is a sugar-coated tablet or an FC tablet. . Examples of the sugar-coated tablet in which the discoloration inhibitor of the present invention is particularly easy to achieve the effect include those in which the sugar-coated layer is composed of sucrose (sucrose) or maltitol. The content of sucrose or maltitol in the sugar coating layer is not particularly limited, and can be set as necessary. In addition, examples of the FC tablet in which the discoloration inhibitor of the present invention is particularly easy to achieve the effect include those in which the film coat is made of a cellulose-based polymer compound such as hydroxypropylmethylcellulose.

In the solid preparation of the present invention, it is possible to reduce the discoloration or discoloration of a printed image made of a dry film, or the light discoloration due to light irradiation such as natural light. Therefore, it is possible to prevent the deterioration of various information printed in order to improve identification for users, such as product information, and this ensures good visibility over a long period of time. Allows prevention.

Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, materials, contents, and the like described in the following examples are not intended to limit the scope of the present invention only to those unless otherwise specified. In addition, each material of the water-based ink composition for inkjet conforms to the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law.

(Preparation of water-based ink composition A for inkjet)
As shown in Table 1 below, 2.4% by weight of red No. 2 as an azo dye (specific dye), 3% by weight of yellow No. 5 and 0.6% by weight of blue No. 1, 15% by weight as other dyes 2 mass% polyglycerin fatty acid esters (trade name: SY Glister, manufactured by Sakamoto Pharmaceutical Co., Ltd.), 7.5 mass% polyethylene glycol as a wetting agent, and 69. 5% by mass of ion-exchanged water was mixed to prepare a black inkjet water-based ink composition A. However, the fading inhibitor was changed for each example as described later.

(Preparation of water-based ink composition B for inkjet)
As shown in Table 1 below, 3.6% by weight of red No. 40 as an azo dye (specific dye), 1.68% by weight of yellow No. 5 and 0.72% by weight of green No. 3, 15% as other dyes 2% by weight polyglycerin fatty acid esters (trade name: SY Glyster, Sakamoto Yakuhin Kogyo Co., Ltd.), 10% by weight polyethylene glycol, 67% by weight as a wetting agent Were mixed with ion-exchanged water to prepare a black inkjet water-based ink composition B. However, the fading inhibitor was changed for each example as described later.

(Preparation of water-based ink composition C for inkjet)
As shown in Table 1 below, 6% by mass of red No. 102 as an azo dye (specific dye), 2% by mass of yellow No. 5 and 2% by mass of blue No. 1, 15% by mass of a fading inhibitor 2 mass% polyglycerin fatty acid esters (trade name: SY Glister, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) as a surface tension adjusting agent, 7.5 mass% polyethylene glycol as a wetting agent, 65.5 mass% ion Exchange water was mixed to prepare a black inkjet water-based ink composition C. However, the fading inhibitor was changed for each example as described later.

(Preparation of water-based ink composition D for inkjet)
The water-based ink composition D for inkjet was prepared in the same manner as the water-based ink composition A except that no fading inhibitor was added and the blending ratio shown in Table 2 below was used.

(Preparation of water-based ink composition E for inkjet)
The water-based ink composition E for inkjet was prepared in the same manner as the water-based ink composition B except that no fading inhibitor was added and the blending ratio shown in Table 2 below was used.

(Preparation of water-based ink composition F for inkjet)
The water-based ink composition F for inkjet was prepared in the same manner as the water-based ink composition C, except that no fading inhibitor was added and the blending ratio shown in Table 2 below was used.

(Examples 1 to 24)
The water-based ink compositions used in Examples 1 to 24 were as shown in Tables 3 to 5 below. In addition, as the fading inhibitor, those shown in Tables 3 to 5 below were used. As the reduced isomaltulose used in Examples 16 to 18, Palatinit (registered trademark, manufactured by Mitsui Sugar Co., Ltd.) was used.

Using the water-based ink composition of each example, printing was performed on one surface of a sugar-coated tablet (sugar-coated layer is sucrose) by an inkjet recording method. Printing was performed by a single pass (one pass) method using an inkjet printer (KC 600 dpi head, medium speed printing jig). Printing was performed in an environment with an air temperature of 25 ° C. and a relative humidity of 40%. Thereafter, hot air was directly applied with a dryer to sufficiently dry the printed surface. This produced the sample of each Example.

(Comparative Examples 1 to 3)
The aqueous ink compositions used in Comparative Examples 1 to 3 were as shown in Table 5 above.

Furthermore, using the water-based ink composition of each comparative example, printing was performed on a sugar-coated tablet by the inkjet recording method in the same manner as in the above-described example. This produced the sample of each comparative example.

(Evaluation on discoloration suppression)
The discoloration inhibiting properties of the aqueous ink compositions in the samples of Examples 1 to 24 and Comparative Examples 1 to 3 were evaluated by conducting the following tests. First, for the images printed on the samples of each Example and Comparative Example, using a color difference meter (model number: VSS7700, manufactured by Nippon Denshoku Industries Co., Ltd.), L in the L ^* a ^* b ^* color system The initial values of ^* ₀ , a ^* ₀ , and b ^* ₀ were measured (in Tables 6 to 14, the values of L ^* , a ^* , and b ^* when the storage time was 0 hours).

Subsequently, each sample was stored in a high-temperature and high-humidity tank set at a temperature of 25 ° C. and a relative humidity of 60% for 24 hours. Thereafter, the color difference meter was used again to measure L ^* ₁ , a ^* ₁ , and b ^* ₁ in the L ^* a ^* b ^* color system of each sample (in Tables 6 to 14, storage time 24 L ^* , a ^* , b ^* values in time). The results are shown in Tables 6 to 14 below.

Incidentally, [Delta] L ^* ₁ shown in the ^{_{^{_{tables, Δa * 1, Δb * 1}}}} , ΔE * (ab) 1, ΔC * (ab) 1 and ΔH ^* _{(ab) 1} was calculated by the respective following formulas.
ΔL ^* ₁ = L ^* _1- L ^* ₀
Δa ^* ₁ = a ^* ₁₋ a ^* ₀
Δb ^* ₁ = b ^* ₁₋ b ^* ₀
ΔE ^* (ab) ₁ = ((ΔL ^* ₁ ) ² + (Δa ^* ₁ ) ² + (Δb ^* ₁ ) ² ) ^1/2
ΔC ^* (ab) ₁ = ((Δa ^* ₁ ) ² + (Δb ^* ₁ ) ² ) ^1/2
ΔH ^* (ab) ₁ = (ΔE ^* (ab) ₁ ² −ΔL ^* ₁ ² −ΔC ^* (ab) ₁ ² ) ^1/2

(Evaluation on light fading suppression)
The fading suppression property of the water-based ink composition of each example was evaluated by performing the following tests. That is, about the sugar-coated tablet (sample) after the inkjet printing by the water-based ink composition which concerns on each Example and a comparative example, respectively using a color difference meter (model number: VSS7700, Nippon Denshoku Industries Co., Ltd. make) L ^* a ^* L ^* ₀ , a ^* ₀ , and b ^* ₀ in the b ^* color system were measured respectively (in Tables 15 to 23, the values of L ^* , a ^* , and b ^* at an integrated light amount of 0 lux).

Subsequently, using a light stability test apparatus (manufactured by Nagano Science Co., Ltd.) compliant with the ICH guidelines, the printed sample stored in a sealed glass bottle was irradiated with light. The integrated light quantity at this time was 1.2 million lux (for 50 days in terms of indoor fluorescent light). Thereafter, the color difference meter was used again to measure L ^* ₂ , a ^* ₂ , and b ^* ₂ in the L ^* a ^* b ^* color system of each sample (in Tables 15 to 23, the accumulated light amount 120 L ^* , a ^* , b ^* values in 10,000 lux). The results are shown in Tables 15 to 23 below.

In addition, ΔE ^* (ab) ₂ , ΔL ^* ₂ , Δa ^* ₂ , Δb ^* ₂ , ΔC ^* (ab) ₂ and ΔH ^* (ab) ₂ shown in each table were calculated by the following general formulas.
ΔE ^* (ab) ₂ = ((ΔL ^* ₂ ) ² + (Δa ^* ₂ ) ² + (Δb ^* ₂ ) ² ) ^1/2
ΔL ^* ₂ = L ^* _2- L ^* ₀
Δa ^* ₂ = a ^* _2- a ^* ₀
Δb ^* ₂ = b ^* _2- b ^* ₀
ΔC ^* (ab) ₂ = ((Δa ^* ₂ ) ² + (Δb ^* ₂ ) ² ) ^1/2
ΔH ^* (ab) ₂ = (ΔE ^* (ab) ₂ ² −ΔL ^* ₂ ² −ΔC ^* (ab) ₂ ² ) ^1/2

(result)
As shown in Table 14, in the samples of Comparative Examples 1 to 3, the a ^* value of the printed image printed on the sugar-coated tablet greatly decreases after being stored for 24 hours in an environment of a temperature of 25 ° C. and a relative humidity of 60%. It was shown that. That is, it was confirmed that the value of Δa ^* ₁ was extremely small, and the printed image was changed from black to green.

On the other hand, as shown in Tables 6 to 13, in the samples of Examples 1 to 24, the amount of decrease in the a ^* value of the printed image was reduced, and it was possible to suppress the Δa ^* ₁ value from becoming smaller. . It was also confirmed that the color change from black to green was sufficiently suppressed in the printed image. In particular, reduced isomaltulose was excellent in suppressing discoloration caused by humidity as compared with other saccharides. Thereby, the monosaccharide, disaccharide, dextrin and sugar alcohols suppress discoloration to the black aqueous ink composition containing each of the red No. 2, red No. 40 and red No. 102 azo dyes. It was shown to be extremely effective.

As shown in Table 23, in the samples of Comparative Examples 1 to 3, the color difference ΔE ^* (ab) _{2 of} the printed image printed on the sugar-coated tablet is larger than that immediately after printing, and the printed image is greatly lightened. It was confirmed to be fading.

On the other hand, as shown in Tables 15 to 22, in the samples of Examples 1 to 24, the increase in the color difference ΔE ^* (ab) ₂ of the printed images printed on the sugar-coated tablets was significantly suppressed, and all were 17 or less. It was. Thereby, in the present Example, it was confirmed that the photodecomposition of azo dyes such as Red No. 2 in the printed image can be reduced and the photofading can be reduced.

Claims

An aqueous inkjet ink composition used for printing on a solid preparation,
Containing an edible dye and a fading inhibitor,
The dye is at least one selected from the group consisting of Red No. 2, Red No. 4, Red No. 40, Red No. 102, Yellow No. 4, Yellow No. 5, Green No. 3, Blue No. 1 and copper chlorophyllin sodium. Containing a dye and another dye as an optional component,
The discoloration inhibitor is at least one selected from the group consisting of monosaccharides, disaccharides, dextrins and sugar alcohols;
Furthermore, the water-based ink composition for inkjets, wherein the content of the fading inhibitor is 50% by mass or less based on the total mass of the water-based ink composition.
The aqueous ink composition for inkjet according to claim 1, wherein the monosaccharide is at least one of galactose and fructose.
The aqueous ink composition for inkjet according to claim 1 or 2, wherein the disaccharide is at least one of maltose and trehalose.
The water-based ink composition for inkjet according to any one of claims 1 to 3, wherein the dextrins are cyclodextrins.
The aqueous ink composition for inkjet according to any one of claims 1 to 4, wherein the sugar alcohol is at least one selected from the group consisting of reduced isomaltulose, xylitol, and sorbitol.
In the method for suppressing discoloration of a printed image printed on a solid preparation,
An aqueous inkjet ink composition comprising an edible dye and a fading inhibitor, wherein the dye is Red No. 2, Red No. 4, Red No. 40, Red No. 102, Yellow No. 4, Yellow No. 5, Green No. 3, Blue No. 1 and at least one specific dye selected from the group consisting of copper chlorophyllin sodium and other dyes as optional components, wherein the discoloration inhibitor is a monosaccharide, disaccharide, dextrin A water-based ink composition for inkjet, which is at least one selected from the group consisting of alcohols and sugar alcohols, and the content of the fading inhibitor is 50% by mass or less based on the total mass of the water-based ink composition. A preparation step of preparing an aqueous inkjet ink;
Printing on the surface of the solid preparation by an inkjet method using the water-based ink for inkjet, and forming the printed image; and
A method for suppressing discoloration of a printed image of a solid preparation, wherein the discoloration suppressing agent in the printed image includes a discoloration suppressing step of suppressing penetration of the specific dye into the solid preparation.
The discoloration suppressing step is based on the printed image of the solid preparation immediately after the printing step, based on JIS Z 8730 of the printed image of the solid preparation after being stored for 24 hours in an atmosphere of a temperature of 25 ° C. and a relative humidity of 60%. The method for suppressing discoloration of a printed image of a solid preparation according to claim 6, wherein Δa * of the L * a * b * color system is -18 or more.
The method for suppressing discoloration of a printed image of a solid preparation according to claim 6 or 7, wherein the discoloration suppressing agent in the printed image further includes a light discoloration suppressing step of suppressing photodecomposition of the specific dye.
The light fading suppression step is based on L * a in accordance with JIS Z 8781 of a printed image in a solid preparation after irradiation with visible light having an integrated light amount of 1.2 million lux, based on the printed image in the solid preparation immediately after the printing step. The method for suppressing discoloration of a printed image of a solid preparation according to claim 8, wherein the color difference ΔE * (ab) of the * b * color system is 17 or less.
The method for suppressing discoloration of a printed image of a solid preparation according to any one of claims 6 to 9, wherein the monosaccharide is at least one of galactose and fructose.
The method for suppressing discoloration of a printed image of a solid preparation according to any one of claims 6 to 10, wherein the disaccharide is at least one of maltose and trehalose.
The method for suppressing discoloration of a printed image of a solid preparation according to any one of claims 6 to 11, wherein the dextrins are cyclodextrins.
The method for suppressing discoloration of a printed image of a solid preparation according to any one of claims 6 to 12, wherein the sugar alcohol is at least one selected from the group consisting of reduced isomaltulose, xylitol, and sorbitol.
A solid preparation having a dry film of a water-based inkjet ink on the surface,
6. A solid preparation, wherein the inkjet water-based ink comprises the inkjet water-based ink composition according to any one of claims 1 to 5.