JP6574065B2 - Aqueous ink composition for ink jet and solid preparation - Google Patents

Description

  The present invention relates to an aqueous inkjet ink composition and a solid preparation, and more specifically, to an inkjet aqueous ink composition that can be directly printed by an inkjet method on tablets such as pharmaceuticals and foods and has excellent drying properties. And solid formulations.

  With the advent of inkjet printing devices for tablets and water-based ink compositions that meet standards such as the Pharmaceutical Affairs Law, printing is possible directly on uncoated tablets and OD (orally disintegrating) tablets, which have been difficult to print. It became so. For this reason, inkjet tablet printers have rapidly spread in the production sites of domestic pharmaceutical manufacturers. Under such circumstances, pharmaceutical manufacturers who possess inkjet printers need to print on film-coated tablets, sugar-coated tablets, etc., as well as uncoated tablets and OD tablets, using inkjet printers with excellent print image quality. Has occurred.

  However, among the tablets and the like, film-coated tablets and sugar-coated tablets are solid preparations into which the aqueous ink composition hardly permeates. Therefore, when printing directly on these solid preparations using an aqueous ink composition by an inkjet method, it is difficult to penetrate and dry the aqueous ink composition, so moisture and moisture contained in the aqueous ink composition As for the agent, it is necessary to volatilize them all and dry them.

  However, humectants such as edible polyhydric alcohols such as glycerin and propylene glycol that have been used so far have a very high boiling point compared to water, so that volatilization does not proceed sufficiently (see Patent Document 1 and Patent Document below). 2). For this reason, there is a problem of causing poor drying of the printed image.

JP 2010-235765 A JP 2014-159520 A

  The present invention has been made in view of the above-mentioned problems, and its purpose is that it can be directly printed on a solid preparation such as pharmaceuticals and foods by an ink jet method, and has excellent drying properties and discharge stability. It is to provide an aqueous ink composition and a solid preparation.

  In order to solve the above problems, the inventors of the present application have studied an aqueous inkjet ink composition and a solid preparation. As a result, the inventors have found that the above problems can be solved by adopting the following configuration, and have completed the present invention.

  That is, the aqueous ink composition for inkjet according to the present invention is an aqueous inkjet ink composition used for inkjet recording in order to solve the above-mentioned problems, and comprises water, at least one colorant and a solid wetting agent. The solid wetting agent is at least contained in a solid state at room temperature and normal pressure, and an edible water-soluble polymer compound having a number average molecular weight of 100,000 or less is dissolved in the water. In addition, the water-based ink composition for inkjet does not include a liquid wetting agent that is liquid in a simple form at normal temperature and pressure.

  In the water-based inkjet ink composition of the present invention (hereinafter sometimes referred to as “water-based ink composition”), an edible water-soluble polymer compound that is solid in a single state at normal temperature and pressure is a solid wetting agent. Exist in a dissolved state. Therefore, for example, when the aqueous ink composition of the present invention is directly printed on the surface of a solid preparation such as a tablet by an ink jet method, only water in the aqueous ink composition is volatilized in the printed coating film, The edible water-soluble polymer compound remains as a part of the dried coating film. That is, unlike conventional liquid wetting agents, it is not necessary to volatilize with water and dry. In addition, since the aqueous ink composition of the present invention does not use such a conventional liquid wetting agent in combination with a solid wetting agent, energy for drying the printed image is not required as compared with the conventional aqueous ink composition. Thus, the drying time can be shortened, and an aqueous ink composition having excellent drying properties can be provided. “Liquid wetting agent” means a material that has a function of suppressing evaporation at the head end surface of the aqueous ink composition because it takes a liquid form alone at room temperature and normal pressure and has a boiling point higher than that of water. To do.

  Furthermore, the present invention uses edible water-soluble polymer compounds having a number average molecular weight of 100,000 or less. This prevents the viscosity of the water-based ink composition from becoming excessively large or greatly deviates from the Newtonian state, and allows the water-based ink composition to be stably ejected from the ink jet nozzles, with flying properties. The decrease can be suppressed.

  Here, the term “edible” in the edible water-soluble polymer compound refers to only substances that are approved for oral administration as pharmaceuticals or pharmaceutical additives and / or substances that are recognized as foods or food additives. It means to become. Accordingly, the aqueous ink composition for inkjet according to the present invention enables direct printing on tablets or the like of pharmaceuticals and foods. In addition, “water-soluble” means that 1 g or more is dissolved in 100 g of water at room temperature and normal pressure.

  The “inkjet recording” means a method of discharging an aqueous inkjet ink composition as droplets from a fine inkjet head, fixing the droplets on a recording medium, and forming an image. It is not limited to paper or the like, and includes solid preparations such as pharmaceuticals and foods. The “normal temperature” means that the temperature is in the range of 5 ° C. to 35 ° C. The “normal pressure” means a pressure (standard atmospheric pressure) in the vicinity of the atmospheric standard state, and the atmospheric standard state is a temperature of about 25 ° C. and an atmospheric pressure condition of about 101 kPa in absolute pressure. Means that. In addition, “normal pressure” may include a slightly positive pressure or a negative pressure with respect to the standard atmospheric pressure.

  In the above configuration, the edible water-soluble polymer compound is selected from the group consisting of polyethylene glycol, polyvinyl pyrrolidone, alginates, sodium polyacrylate, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, polysorbate, and polyvinyl pyrrolidone. It is preferable that it is at least one compound selected.

Is further In the above structure, the polyethylene glycol has the general formula _{OHCH 2 (CH 2 OCH 2)} n CH 2 OH ( where the n is. A natural number ranging from 20 to 500) is a compound represented by It is preferable.

  In the above configuration, the colorant may be at least one edible dye selected from the group consisting of edible synthetic pigments, natural pigment derivatives, natural synthetic pigments, and edible natural pigments.

  Furthermore, in the said structure, it is preferable that content of the said edible dye exists in the range of 0.2 mass%-20 mass% with respect to the total mass of the said water-based ink composition for inkjets.

  Moreover, in the said structure, the said colorant may be a pigment and may further contain the pigment dispersant which disperse | distributes the said pigment further.

  The aqueous inkjet ink composition preferably has edible properties. “Edible” means the same as “edible” in the edible water-soluble compound.

  In order to solve the above-described 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 includes the inkjet aqueous ink composition. The dry film is at least composed of the colorant contained in the inkjet aqueous ink composition and the solid wetting agent dissolved and contained in the inkjet aqueous ink composition. It is characterized by being.

  The inkjet ink contains the aqueous ink composition, and the edible water-soluble polymer compound as a solid wetting agent is present in the aqueous ink composition in a dissolved state. Here, when ink-jet ink adheres to the surface of the solid preparation by ink-jet printing and a coating film is formed, the moisture in the coating film volatilizes and dries, and consists of a dry film containing a colorant. A print image is formed. On the other hand, since the solid wetting agent is originally composed of a single solid edible water-soluble polymer compound at normal temperature and pressure, the solid wetting agent does not volatilize with moisture. Therefore, the solid wetting agent also remains as one of the compositions constituting the dry film together with the colorant.

  And since the water-based ink composition containing the edible water-soluble polymer compound as a solid wetting agent is excellent in drying properties, for example, a solid preparation in which water-based inks such as film-coated tablets and sugar-coated tablets do not substantially penetrate inside. Even so, it is possible to reduce the occurrence of ink stains due to poor drying. That is, with the above-described configuration, it is possible to provide a solid preparation in which a printed image is free from contamination due to poor drying and a good printed image is formed by a dry film. As a result, for example, product information or the like can be directly displayed on the solid preparation, and it is possible to provide a solid preparation that can improve discrimination and prevent dispensing errors and accidental ingestion. The solid preparation of the present invention is meant to include food preparations and pharmaceutical preparations.

  The aqueous ink composition for inkjet according to the present invention contains a solid edible water-soluble polymer compound as a solid wetting agent in a dissolved state at room temperature and normal pressure. Therefore, for example, when the water-based ink composition of the present invention is used to directly print on the surface of a solid preparation such as a tablet by an ink jet method, printing is performed by volatilizing only water without volatilizing the solid wetting agent. The image can be dried. As a result, the water-based ink composition of the present invention can shorten the drying time of the printed image and can have excellent drying properties as compared with the conventional water-based ink composition using a liquid wetting agent. As a result, it is possible to prevent ink stains due to poor drying from occurring in the printed image. In addition, since the edible water-soluble polymer compound having a number average molecular weight of 100,000 or less is used, it is possible to prevent the viscosity of the water-based ink composition from excessively increasing or from greatly deviating from the Newtonian state. In addition, it can be made excellent in ejection stability such as flight characteristics. As a result, a good printed image can be obtained. Furthermore, since the edible water-soluble polymer compound complies with standards such as the Pharmaceutical Affairs Law, it can be directly printed on solid preparations such as pharmaceuticals and foods. As a result, it is possible to display product information directly on the solid preparation body, improve the discrimination, and prevent dispensing errors and accidental ingestion.

  That is, according to the present invention, it is possible to directly print on solid preparations such as pharmaceuticals and foods by an inkjet method, and an aqueous inkjet ink composition excellent in drying property and ejection stability, and the inkjet A solid preparation printed with the aqueous ink composition 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 aqueous ink composition of the present embodiment is an aqueous ink containing water as a main solvent, at least one colorant, and a solid wetting agent. Further, the aqueous ink composition of the present embodiment does not contain a liquid wetting agent. The water-based ink composition of the present embodiment can be made edible by using a material that complies with the standards of pharmaceutical additives, Japanese Pharmacopoeia or Food Additives specified by the Pharmaceutical Affairs Law, And it is used suitably for inkjet recording.

  Examples of the colorant include edible dyes. Such a dye is not particularly limited, and examples thereof include edible synthetic pigments (synthetic tar pigments), natural pigment derivatives, natural synthetic pigments, and edible natural pigments.

  Examples of the edible synthetic pigment 0 include at least one selected from the group consisting of azo dyes, triphenylmethane dyes, xanthene dyes, and indigoid dyes. Further, the azo dye is not particularly limited, and examples thereof include food red No. 2, food red No. 102, food red No. 40, food yellow No. 4, food yellow No. 5, and the like. The triphenylmethane dye is not particularly limited, and examples thereof include edible blue No. 1 and edible green No. 3. The xanthene dye is not particularly limited, and examples thereof include edible red No. 3, edible red No. 104, edible red No. 105, and edible red No. 106. Examples of the indigoid dye include edible blue No. 2.

  It does not specifically limit as said natural pigment derivative, For example, copper chlorophyllin sodium etc. are mentioned.

  The natural synthetic dye is not particularly limited, and examples thereof include β-carotene.

  The edible natural dye is not particularly limited, and examples thereof include anthocyanin dyes, carotenoid dyes, quinone dyes, flavonoid dyes, cochineal dyes, copper chlorophyllin sodium, cacao dyes, and caramel dyes.

  The dyes exemplified above can be used alone or in admixture of two or more as necessary. In addition, these dyes comply with the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law.

  The content of the dye is not particularly limited, but is usually in the range of 0.2% by mass to 20% by mass, preferably 1% by mass to 10% by mass with respect to the total mass of the aqueous ink composition. . By setting the content of the dye to 0.2% 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, by setting the content of the dye to 20% by mass or less, it is possible to prevent the dye component from being deposited in the nozzle of the inkjet head.

  The solid wetting agent is made of an edible water-soluble polymer compound, and the edible water-soluble polymer compound is present alone in a solid state at normal temperature and pressure. Further, the edible water-soluble polymer compound is water-soluble and exists in a dissolved state in the aqueous ink composition. When printing is performed by attaching droplets of an aqueous ink composition to the surface of a printing material by an inkjet method, when the droplets are dried, the edible water-soluble polymer compound does not volatilize with moisture and is dried with a colorant. Form a film. Therefore, the water-based ink composition of the present embodiment can be made excellent in drying properties. Further, the edible water-soluble polymer compound has hygroscopicity and water retention and functions as a wetting agent. Therefore, the edible water-soluble polymer compound imparts or improves the wettability function to the aqueous ink composition. Thereby, in the water-based ink composition of the present embodiment, for example, at the tip of the ink jet nozzle, it is dried by evaporation of water, and clogging is prevented, and ejection stability such as flying performance is improved. Are better. The “solid” means that the edible water-soluble polymer compound is present in the form of, for example, a crystal, a powder, or a particle.

  In addition, the water-based ink composition of the present embodiment does not include a liquid wetting agent that is in a liquid state at normal temperature and pressure. When such a liquid wetting agent is contained in the aqueous ink composition, for example, when printing on a solid preparation that is difficult to penetrate the aqueous ink composition, such as a film-coated tablet or a sugar-coated tablet, the liquid together with moisture It is necessary to evaporate the wetting agent and dry it. Therefore, the drying time of the printed coating film cannot be shortened, and the drying property of the water-based ink composition is lowered, which may cause ink stains on the printed image. Examples of liquid wetting agents include glycerin and propylene glycol.

  The edible water-soluble polymer compound has a number average molecular weight of 100,000 or less, preferably 2000 to 8000, more preferably 3000 to 50000. By setting the number average molecular weight of the edible water-soluble polymer compound to 100,000 or less, the viscosity of the water-based ink composition is excessively increased or the viscosity greatly deviates from the Newtonian state. It is possible to prevent the flying property of the droplet from being lowered. In addition, by setting the number average molecular weight of the edible water-soluble polymer compound to 2000 or more, depending on the type of the edible water-soluble polymer compound, it is prevented from becoming a liquid or a paste alone at room temperature and normal pressure. can do. Moreover, even when taking a solid form alone at normal temperature and pressure, it is possible to prevent the hardness of the dried coating film after printing from becoming insufficient due to drying conditions and the like.

  The number average molecular weight can be determined by polystyrene conversion by gel permeation chromatography (GPC). For example, in the measurement using LC-6A manufactured by Shimadzu Corporation, the separation column Polymer Laboratories PL gel 5 μm MIXED-C: solvent, dimethylformamide (0.01 mol LiBr added): column flow rate 1.0 ml / min: column temperature 50 ° C. : It can be measured using a RI detector under the condition of a sample concentration of 0.2% (W / V).

  The edible water-soluble polymer compound preferably conforms to the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law. Specifically, for example, polyethylene glycol, polyvinylpyrrolidone And alginates such as sodium alginate, sodium polyacrylate, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, polysorbate, polyvinylpyrrolidone and the like. Of these edible water-soluble polymer compounds, polyethylene glycol and polyvinyl pyrrolidone are preferred in the present embodiment.

The polyethylene glycol is represented by the general formula OHCH ₂ (CH ₂ OCH ₂ ) _n CH ₂ OH (where n is a natural number), and in the present embodiment, n is preferably in the range of 20 to 500. , 30 to 220 is more preferable, and 59 to 84 is particularly preferable. As the polyethylene glycol, a commercially available product can be used. Examples of such a commercially available product include Macrogol (registered trademark) 4000 (trade name, manufactured by Sanyo Chemical Industries, Ltd., number average molecular weight of about 3000). Etc.

  The polyvinyl pyrrolidone is a water-soluble polymer compound obtained by vinyl polymerization of N-vinyl pyrrolidone. For example, a homopolymer (homopolymer) of vinyl pyrrolidone such as N-vinyl-2-pyrrolidone and N-vinyl-4-piperidone. ) And copolymers thereof.

  Commercially available products may be used as the polyvinyl pyrrolidone. Examples of such commercially available products include polyvinyl pyrrolidone K12 (trade name, manufactured by BASF Japan Ltd., number average molecular weight of about 4000), polyvinyl pyrrolidone K17. (Trade name, manufactured by BASF Japan Ltd., number average molecular weight of about 10,000), polyvinylpyrrolidone K30 (trade name, manufactured by BASF Japan Ltd., number average molecular weight of about 40000) and the like.

  In the edible water-soluble polymer compound of the present embodiment, the compounds exemplified above may be used alone or in combination of two or more.

  The addition amount of the solid wetting agent is preferably set so that the viscosity of the water-based ink composition falls within the numerical range described later, depending on the purpose of use and the like. In particular, the upper limit of the amount of solid wetting agent added is preferably set so that the viscosity of the aqueous ink composition does not become excessively high. On the other hand, the lower limit of the addition amount of the solid wetting agent is within a range in which the viscosity of the aqueous ink composition is appropriate, preventing clogging in the vicinity of the nozzle of the inkjet head, and further improving the ejection performance. It is preferable that the value is not less than a value that can be achieved.

  Further, the water-based ink composition of the present embodiment may contain a surface tension adjusting agent. The surface tension modifier is not particularly limited as long as it conforms to standards such as the Pharmaceutical Affairs Law, for example, caprylic acid decaglyceryl, lauric acid hexaglycerin ester, oleic acid hexaglycerin ester, condensed linolenic acid tetraglycerin ester, Examples include fatty acid ester palm palm, decaglyceryl laurate having an HLB of 15 or less, and decaglyceryl oleate having an HLB of less than 13. You may use these individually by 1 type or in mixture of 2 or more types.

A commercially available product can be used as the decaglyceryl caprylate, and 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 said decaglyceryl laurate, that whose HLB is 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. In addition, as decaglyceryl laurate having an HLB of 15 or less, a commercially available product can be used. As such a commercially available product, for example, NIKKOL (registered trademark) DECAGLYN 1-L (trade name, Nikko Chemicals ( Co., Ltd., HLB value 14.5), SY Glister ML-750 (trade name, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 14.8), and the like.

  As said decaglyceryl oleate, that whose HLB is 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. In addition, as decaglyceryl oleate having an HLB of less than 13, a commercially available product can be used. 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.

  A commercially available product can be used as the fatty acid ester palm palm. 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 0.5% by mass to 5% by mass and preferably in the range of 1% by mass to 3% by mass with respect to the total mass of the aqueous ink composition. Is more preferable. When the content of the surface tension adjusting agent is 0.5% by mass or more, when printing is performed by an inkjet method, ejection failure due to poor meniscus surface formation at the nozzle in the inkjet head is prevented, and It is possible to prevent clogging and blurring of the printed image. As a result, the discharge stability can be improved. On the other hand, when the content of the surface tension adjusting agent is 5% 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.

  Further, in the water-based ink composition of the present embodiment, other additives may be blended. However, when used as an ink-jet ink for solid preparations such as pharmaceuticals, it is preferably one that complies with the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law. Examples of the additive 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 necessary.

  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 the like 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.

  The viscosity of the water-based ink composition is preferably 2 mPa · s to 6 mPa · s and more preferably 3 mPa · s to 5 mPa · s when the ink jet nozzle is discharged in consideration of discharge stability from the ink jet nozzle. By setting the viscosity of the water-based ink composition within the above numerical range, the occurrence of clogging at the ink jet nozzle can be suppressed, good discharge stability can be maintained, and the flying property can be prevented from lowering. The viscosity of the water-based ink composition can be obtained, for example, by measuring using a viscometer (trade name: VISCOMATE MODEL VM-10A, manufactured by Seconic Corporation) at a measurement temperature of 25 ° C.

  The water-based ink composition of the present embodiment can be produced by mixing the aforementioned components by an appropriate method. The mixing method and the order of addition are not particularly limited. After mixing, the mixture is sufficiently stirred, and 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 disper, 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 aqueous ink composition of the present embodiment can be applied to ink and paint. In addition, the aqueous ink composition of the present embodiment is excellent in ejection stability when used for printing by an inkjet method, and therefore can be suitably used for inkjet ink. In particular, the water-based ink composition of the present embodiment uses a pharmaceutical additive, a colorant and a solid wetting agent that meet the standards of the Pharmaceutical Affairs Law, the Japanese Pharmacopoeia, or the Food Additives Standard, etc. Therefore, it has edible properties and can be printed directly on the surface of a solid agent comprising tablets or capsules such as pharmaceuticals or supplements. In addition, non-contact printing by an ink jet method is possible even for tablets with poor surface smoothness such as uncoated tablets and OD tablets.

(Solid preparation)
The solid preparation of the present embodiment is composed of, for example, a tablet or a capsule, and the surface of the solid agent is directly printed by an ink jet recording method using the aqueous ink for ink jet composed of the aqueous ink composition. A printed image made of a dry film is formed.

  The dry film is composed of at least a colorant contained in the water-based ink composition and a solid wetting agent dissolved and contained in the water-based ink composition. As described above, the solid wetting agent is solid at room temperature and normal pressure alone. Therefore, after the inkjet aqueous ink printed on the surface of the solid preparation by the inkjet recording method is dried on the surface of the solid preparation, the solid wetting agent may volatilize together with the moisture contained in the inkjet aqueous ink. Absent. Therefore, the solid wetting agent is solidified together with the colorant and constitutes a part of the dry film as a solid component.

  In addition, since the water-based ink for inkjet printing printed on the surface of the solid preparation needs only to evaporate only water, the drying time can be shortened and the drying property is excellent. As a result, in the present embodiment, it is possible to provide a solid preparation with reduced ink stains due to poor drying compared to a solid preparation printed with a conventional inkjet aqueous ink. As a result, the solid preparation of the present embodiment can print various types of information such as product information for improving the identifiability for the user, thereby preventing dispensing mistakes and accidental ingestion.

  The tablet is solid at room temperature, and for example, a tablet material containing an active ingredient is preferably produced by compression and / or molding into a certain shape. The capsule is preferably prepared by filling a powder, granule, liquid or the like in a capsule made of gelatin, cellulose derivative or the like, or encapsulating with a capsule base. The shape of a tablet and a capsule is not specifically limited, Arbitrary shapes can be employ | adopted. Since the water-based ink composition of the present embodiment is excellent in drying properties as compared with conventional ones, it is particularly suitable for tablets and capsules in which the water-based ink composition is difficult to penetrate, such as film-coated tablets and sugar-coated tablets. It is applicable to. The tablet may be a pharmaceutical tablet or a food tablet. Examples of tablets for food use include health foods such as tablet confectionery and supplements.

  The method for forming the dry film of the water-based ink for ink jet on the surface of the solid preparation is not particularly limited, and for example, it can be formed by the ink jet recording method. Specifically, for example, the ink-jet aqueous ink containing the aqueous ink composition can be ejected as droplets from a fine nozzle, and the droplets can be adhered to the surface of the solid preparation. Since the water-based ink composition contains an edible water-soluble polymer compound as a solid wetting agent, occurrence of clogging at the ink jet nozzle is suppressed. 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. .

  Thereafter, the droplets adhering to the surface of the solid preparation are dried. Since the water-based ink for ink-jet of this embodiment contains a solid edible water-soluble polymer compound as a solid wetting agent alone at normal temperature and pressure, drying of droplets is performed in the water-based ink for ink-jet. It is sufficient to volatilize only the moisture contained. Therefore, the drying of the liquid droplets is completed in a short time as compared with the inkjet water-based ink using a conventional liquid wetting agent. As a result, a printed image composed of a dry film composed of at least the colorant and the solid wetting agent is formed on the surface of the solid preparation.

(Other matters)
In the present embodiment, the case where a dye is used as a colorant has been described as an example. However, the present invention is not limited to this, and for example, a pigment can be used. In this case, you may add other well-known additives, such as a pigment dispersant, as needed.

  As said pigment, what is normally used for the water-based ink composition for inkjets, such as carbon black, can be used, for example. The carbon black is not particularly limited, and examples thereof include channel black, furnace black, acetylene black, and thermal black. Moreover, it is also possible to use a commercial item as carbon black of this Embodiment, As such a commercial item, # 900, # 970, # 100, # 2200, # 2300, # 2350, # 2600, MA-7, MA-8, MA-100, MA-11, MCF88, # 45L, # 50, # 10, # 33, # 40, # 4000, # 52, CF9, etc. (trade names, all Mitsubishi Chemical Co., Ltd.), Niteron, HTC (trade names, all manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), Asahi # 55, Asahi # 51, Asahi # 50U, Asahi # 50, Asahi # 35, Asahi # 15, Asahi Thermal (product) Name, all manufactured by Asahi Carbon Co., Ltd.), Raven700, 5750, 5250, 5000, 3500, 1255 (trade names, all manufactured by Columbia), REGAL400R, 330R, 660R, ogulL, Monarch 700, 800, 880, 900, 1000, 1100, 1300, Monarch 1400 (product names, all manufactured by Cabot), Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170 (product names, any Also manufactured by Degussa), PRINTEX35, U, V, 140U, 140V (trade names, all manufactured by Degussa), Special Black 6, 5, 4A, 4 (trade names, all manufactured by Degussa), TOKABLACK # 8500, # 8300, # 7550, # 7400, # 7350, # 7240, # 7100, # 7050, # 5500, # 4500, # 4400, # 4300 (trade names, all manufactured by Tokai Carbon Co., Ltd.) and the like. These pigments can be used alone or in admixture of two or more as required. However, when the pigment composition of the present embodiment is used for printing on the surface of solid preparations such as pharmaceuticals and supplements, carbon black is a pharmaceutical additive specified by the Pharmaceutical Affairs Law or a food additive specified by the Food Sanitation Law. Is preferred.

  As the pigment, for example, iron oxide can be used. Examples of the iron oxide include yellow iron oxide, yellow ferric oxide, ferric oxide, red iron oxide, black iron oxide, and the like. Furthermore, a self-dispersing pigment may be used as the pigment. These pigments can be used alone or in admixture of two or more as required. However, when the pigment composition of the present embodiment is used for printing on the surface of tablets such as pharmaceuticals and supplements, iron oxide conforms to the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law. It is preferable that they are compatible.

  The content of the pigment directly affects the image density. When printing on a water-based ink composition, such as storage stability, viscosity, pH, and tablets, the printing density is affected. It is sufficient to set appropriately considering this point. Usually, the range of 0.5% by mass to 40% by mass is preferable with respect to the total mass of the pigment composition, and the range of 1% by mass to 25% by mass is more preferable. By setting the pigment content to 0.5 mass% or more, it is possible to suppress a decrease in image density. On the other hand, by setting the pigment content to 40% by mass or less, it is possible to prevent a decrease in gloss, nozzle clogging, and a decrease in ejection stability.

  As the pigment dispersant, those usually used in an aqueous inkjet ink composition 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 behenyl ether. Examples thereof include oxyethylene alkyl ether, polysorbate, and decaglyceryl oleate. Examples of the anionic surfactant include sodium polyacrylate. These may be used alone or in admixture of two or more. In addition, when a self-dispersing pigment is used as the pigment, the addition of a pigment dispersant may be omitted. However, when the pigment composition of this embodiment is used for printing on the surface of tablets such as pharmaceuticals and foods, it must conform to the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law. It is preferable to use it.

  The content ratio of the pigment to the pigment dispersant is preferably 1: 0.2 to 1: 4, more preferably 1: 0.5 to 1: 1 on a mass basis. When the content ratio is 1: 0.2 or more, it is possible to prevent a decrease in dispersibility of the pigment. On the other hand, when the content ratio is 1: 4 or less, for example, when used in an aqueous inkjet ink composition, it is possible to prevent a decrease in ejection stability due to adhesion of a nozzle plate.

  In the pigment composition, a dispersion medium for dispersing the pigment is included. Examples of the dispersion medium include water, and more specifically, pure water such as ion-exchanged water, ultrafiltrated water, reverse osmosis water, and distilled water, or those obtained by removing ionic impurities such as ultrapure water. . It does not specifically limit as content of a dispersion medium, It can set suitably as needed.

  Further, as the dispersion medium, a mixed solution of the water and the water-soluble organic solvent may be used. The water-soluble organic solvent is not particularly limited, and specifically, for example, alcohols such as methyl alcohol, ethyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, n-propyl alcohol, isopropyl alcohol; Examples thereof include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran. You may use these individually by 1 type or in mixture of 2 or more types. Among these water-soluble organic solvents, ethyl alcohol, n-butyl alcohol, isobutyl alcohol, n-propyl are those that fall under the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law. Alcohol, isopropyl alcohol and acetone are preferred. Furthermore, the blending amount when a water-soluble organic solvent is used as the dispersion medium is not particularly limited, and can be appropriately set as necessary.

  The content of the pigment composition is preferably in the range of 0.5% by mass to 20% by mass and more preferably in the range of 1% by mass to 15% by mass with respect to the total mass of the water-based ink composition. By making the content of the pigment composition 0.5% by mass or more, the coloring power can be improved. On the other hand, dispersibility can be improved by making the content of the pigment composition 20% by mass or less.

  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.

Example 1
In the aqueous ink composition of this example, edible red No. 102, edible yellow No. 5 and edible green No. 3 are used as dyes, and polyethylene glycol (Macrogol (registered trademark)) is used as an edible water-soluble polymer compound as a solid wetting agent. 4000, manufactured by Sanyo Chemical Industries, Ltd., a number average molecular weight of about 3000), and decaglyceryl caprylate was used as a surface tension modifier. The water-based ink composition was prepared by placing it in a container so as to have the composition shown in Table 1 below and stirring with a disper.

  The numerical values in Table 1 below are all expressed in mass% unless otherwise specified. The same applies to numerical values in other tables described later. Each material complies with the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives specified by the Pharmaceutical Affairs Law.

(Comparative Examples 1-3)
In Comparative Examples 1 to 3, the wetting agent was changed to that shown in Table 1 below. Further, the blending amounts of the respective compositions were also changed to the values shown in Table 1 below. Other than that was carried out similarly to the said Example 1, and produced the water-based ink composition of Comparative Examples 1-3, respectively.

  When the water-based ink composition after preparation was confirmed, each dye was completely dissolved in the water-based ink composition of Comparative Examples 1 and 2, but the water-based ink of Comparative Example 3 was used. For the composition, not all dyes could be dissolved, and insoluble matter was generated. Therefore, the water-based ink composition of Comparative Example 3 was not evaluated for the flying property described later.

(Example 2)
In the aqueous ink composition of Example 2, edible red No. 102, edible yellow No. 4 and edible green No. 3 as dyes, and polyvinylpyrrolidone K12 (BASF Japan Ltd.) as an edible water-soluble polymer compound as a solid wetting agent. And a number average molecular weight of about 4000), and decaglyceryl caprylate was used as a surface tension modifier. The aqueous ink composition was prepared by placing it in a container so as to have the composition shown in Table 2 below and stirring with a disper. In addition, each material used in the present Example conforms to the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives defined by the Pharmaceutical Affairs Law.

(Examples 3 and 4)
In Examples 3 and 4, polyvinyl pyrrolidone K17 (manufactured by BASF Japan Ltd., number average molecular weight of about 10,000) and polyvinyl pyrrolidone K30 (manufactured by BASF Japan Ltd., number average molecular weight of about 40,000) were used as solid wetting agents. (See Table 2 below). Further, the blending amounts of the respective compositions were also changed to the values shown in Table 2 below in order to optimize the viscosity to some extent as an aqueous inkjet ink composition. Other than that was carried out similarly to the said Example 2, and produced the water-based ink composition of Example 3 and 4, respectively.

(Comparative Examples 4 and 5)
In Comparative Examples 4 and 5, polyvinyl pyrrolidone K80 (manufactured by Tokyo Chemical Industry Co., Ltd., number average molecular weight of about 160,000) and polyvinyl pyrrolidone K90 (manufactured by BASF Japan Ltd., number average molecular weight of about 36) were used as solid wetting agents. (See Table 2 below). In addition, the blending amounts of the respective compositions were changed to the values shown in Table 2 below. Other than that was carried out similarly to the said Example 2, and produced the water-based ink composition of the comparative examples 4 and 5, respectively.

(Example 5)
In the aqueous ink composition of Example 5, a pigment composed of carbon black as a colorant, polyoxyethylene alkyl ether as a pigment dispersant, polyethylene glycol (Macrogol (registered) as an edible water-soluble polymer compound as a solid wetting agent) Trademark) 4000, manufactured by Sanyo Chemical Industries, Ltd., a number average molecular weight of about 3000), and decaglyceryl caprylate was used as a surface tension modifier. In preparing the water-based ink composition, a pigment composition was first prepared. Preparation of the pigment composition was performed by mixing carbon black, a pigment dispersant, and ion-exchanged water in a container and dispersing the mixture at room temperature for 16 hours using a disperser (Paint Shaker, manufactured by Asada Tekko Co., Ltd.). Subsequently, a surface tension adjusting agent, a wetting agent, and ion-exchanged water were added to the pigment composition so as to obtain a blending composition shown in Table 3 below. This produced the water-based ink composition of Example 5. In addition, each material used in the present Example conforms to the standards of pharmaceutical additives, Japanese pharmacopoeia or official food additives defined by the Pharmaceutical Affairs Law.

(Comparative Example 6)
In Comparative Example 6, the wetting agent was changed to that shown in Table 3 below. Further, the blending amounts of the respective compositions were also changed to the values shown in Table 3 below. Otherwise, the aqueous ink composition of Comparative Example 6 was produced in the same manner as in Example 5.

(Measurement of number average molecular weight)
The number average molecular weights of polyethylene glycol and polyvinyl pyrrolidone are values obtained by gel permeation chromatography under the following conditions using polystyrene as a standard product.
Measuring device: LC-6A (manufactured by Shimadzu Corporation)
Separation column: PL gel 5 μm MIXED-C (manufactured by Polymer Laboratories)
Eluent: Dimethylformamide (0.01 mol LiBr added)
Column flow rate: 1.0 ml / min
Detector: RI detector Column temperature: 50 ° C
Sample concentration: 0.2% (W / V)
Molecular weight standard: Standard polystyrene

(Measurement of viscosity)
The viscosities of the aqueous ink compositions of Examples 1 to 5 and Comparative Examples 1 to 6 were measured. The viscosity was measured using a viscometer (VISCOMATE MODEL VM-10A, manufactured by Seconic Corporation) at a measurement temperature of 25 ° C. The results are shown in Tables 1 to 3.

(Discharge stability (flying performance))
Matte paper (trade name: Superfine paper, manufactured by Epson Corporation) is prepared as a recording medium, and printing is performed using the aqueous ink compositions of Examples 1 to 4 and Comparative Examples 1, 2, 4, and 5, respectively. It was. Printing was performed by a single pass (one pass) method using an inkjet printer (printing jig with KC 600 dpi head).

  The evaluation of the flying property of the water-based ink composition is based on how much nozzle missing increases in the printed image when the water-based ink composition is ejected from the head, and then the printing image is printed again. Depending on whether it was observed. The term “nozzle missing” means that an ink droplet made of a water-based ink composition is not ejected from a nozzle where clogging has occurred. Sleeping means that ink is not ejected in the initial stage of printing, and the printed image writing portion is blurred and unclear.

Evaluation of flight performance was performed using the following criteria. The results are shown in Tables 1 and 2 above.
○: The amount of blurring is less than 1 cm and the number of increase in nozzle clogging is 0. ×: The amount of blurring is 2 cm or more, or the number of increase in nozzle clogging is 10 or more. Δ: The evaluation of flying property does not correspond to any of the above ○ and ×. The evaluation of flying property was performed for printing after an open time of 15 minutes (time interval from when the water-based ink composition was first ejected from the head to stop and then to printing again). Further, the amount of blur is the length (cm) until the writing blur due to ink non-ejection is eliminated in a single-pass print image. The increased number of nozzle clogging means the number of nozzles that are unable to eject ink due to, for example, drying and fixing of ink on the head end face while the inkjet printer is stopped.

(Evaluation of dryness)
Using the aqueous ink compositions of Examples 1 and 5 and Comparative Examples 1, 2, and 6, printing on film-coated tablets was performed by an inkjet recording method. Printing was performed by a single pass (one pass) method using an inkjet printer (printing jig with KC 600 dpi head).

  Moreover, evaluation of drying property (drying speed) was performed by conducting a rubbing test with a cotton cloth on the printing surface of the film-coated tablet. More specifically, the water-based ink composition was discharged from the inkjet head onto the surface of the film-coated tablet, and natural drying was performed for 5 seconds, 10 seconds, 20 seconds, 30 seconds, 60 seconds, 90 seconds, and 120 seconds. Thereafter, each printed surface was rubbed with a cotton cloth, and the presence or absence of printing stagnation with undried ink was confirmed. Confirmation of printing curl was performed by taking a photograph of the scratched surface using an electronic loupe and observing the photograph.

The dryness was evaluated using the following criteria. The results are shown in Table 4 below.
○: No print defects ×: Print defects

(result)
As shown in Table 1 and Table 2, it was confirmed that each of the water-based ink compositions of Examples 1 to 4 had good flightability and excellent ejection performance. On the other hand, in the water-based ink composition of Comparative Example 3, not all dyes could be dissolved. Further, in the water-based ink compositions of Comparative Examples 4 and 5, although the solid wetting agent was used, it was confirmed that the number average molecular weight was more than 100,000, so that the flying property was inferior.

Further, as shown in Table 4, in Examples 1 and 5 using a solid wetting agent, 10 seconds after printing even though the water-based ink composition was printed on a film-coated tablet that hardly penetrates. It was confirmed that the printed surface was free from rubbing and the aqueous ink composition was dry. This confirmed that the drying properties of the aqueous ink compositions of Examples 1 and 5 were excellent. On the other hand, in Comparative Examples 1, 2, and 6 using a liquid wetting agent, rubbing was observed on the printed surface even after 30 seconds or 60 seconds had elapsed since printing. In particular, Comparative Example 1 was a combination of a solid wetting agent and a liquid wetting agent, but no significant improvement in drying properties could be confirmed.

Claims (8)

An ink-jet aqueous ink composition used for ink-jet recording,
At least water, at least one colorant and a solid wetting agent;
The colorant is at least one edible dye selected from the group consisting of edible synthetic pigments, natural pigment derivatives, natural synthetic pigments and edible natural pigments, and is present in a state dissolved in the water,
The solid wetting agent is a single solid at normal temperature and pressure, and an edible water-soluble polymer compound having a number average molecular weight of 100,000 or less is present in a state dissolved in the water,
The water-based ink composition for ink-jets does not contain a liquid wetting agent that is in a liquid state at room temperature and normal pressure.   The edible water-soluble polymer compound is at least one compound selected from the group consisting of polyethylene glycol, polyvinylpyrrolidone, alginates, sodium polyacrylate, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, polysorbate, and polyvinylpyrrolidone. The water-based ink composition for inkjet according to claim 1. The inkjet according to claim _2, wherein the polyethylene glycol is a compound represented by the general formula OHCH ₂ (CH ₂ OCH ₂ ) _n CH ₂ OH (wherein n is a natural number in the range of 20 to 500). A water-based ink composition. The content of the edible dyes, ink-jet according to claim 1 any one total mass to be within the range of 0.2% to 20% by weight of the aqueous ink-jet ink composition A water-based ink composition.   An ink-jet aqueous ink composition used for ink-jet recording,
  At least water, at least one colorant and a solid wetting agent;
  The colorant is an edible pigment;
  Furthermore, a pigment dispersant for dispersing the pigment is included,
  The solid wetting agent is a single solid at normal temperature and pressure, and an edible water-soluble polymer compound having a number average molecular weight of 100,000 or less is present in a state dissolved in the water,
  The ink-jet water-based ink composition does not contain a liquid wetting agent that is a single liquid under normal temperature and pressure, and alcohol as a solvent.
  For the inkjet, the edible water-soluble polymer compound is at least one compound selected from the group consisting of polyvinylpyrrolidone, alginates, sodium polyacrylate, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, polysorbate, and polyvinylpyrrolidone. A water-based ink composition. Aqueous ink-jet ink composition according to claim 1-5 viscosity of the aqueous ink-jet ink composition is in the range of 2mPa · s~6mPa · s. The water-based ink composition for inkjet according to any one of claims 1 to 6, which has edible properties. A solid preparation having a dry film of a water-based inkjet ink on the surface,
The water-based ink for ink-jet includes the water-based ink composition for ink-jet according to any one of claims 1 to 7 ,
The dry film is a solid preparation comprising at least the colorant contained in the inkjet aqueous ink composition and the solid wetting agent dissolved and contained in the inkjet aqueous ink composition.