Edible IJ Ink, Tablets, and Capsules

Abstract

The purpose of the present invention is to provide an an edible IJ ink which exhibits good dispersion stability and print resumability (intermittent resumability), has good drying properties and gives high print quality (that is, streaks and the like are unlikely to occur in printing); and a tablet and capsule having a printed section obtained by printing with this edible IJ ink. Accordingly, this edible IJ ink contains water, titanium oxide, a dispersing agent, a wetting agent and a water-soluble polysaccharide having a weight average molecular weight of less than 10,000. The dispersing agent includes at least one of sodium carboxymethyl cellulose, sodium alginate and sodium carbonate.

Description

Technical Field

[0001] The present invention relates to edible IJ ink, tablets, and capsules.

Background Art

[0002] There is edible ink for inkjet printing (hereinafter, also simply referred to as "IJ ink"). As a technology related to edible inkjet ink (hereinafter, also simply referred to as "edible IJ ink"), for example, there is one described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Some edible IJ inks contain, for example, water-based pigments. When printing on the surface of tablets with low permeability such as FC (film-coated) tablets, sugar-coated tablets, soft capsule tablets, and hard capsule tablets using IJ ink containing a water-based pigment, there are problems such as poor wettability of the ink and the occurrence of streaks in printing. In order to improve the wettability of the ink with respect to tablets with low permeability, there are methods such as adding an alcohol-based solvent or a surfactant to the ink, or adding a solvent that easily spreads. However, the former may cause a decrease in dispersion stability and printing restartability (intermittent restartability), and the latter may cause a decrease in drying property.

[0005] The present invention has been made in view of the above circumstances, and provides an edible inkjet ink having good dispersion stability and printing restartability (intermittent restartability), high drying property, and high printing quality (difficult to generate streaks or the like in printing), a tablet and a capsule agent provided with a printed portion printed with the edible inkjet ink.

Means for Solving the Problems

[0006] The edible inkjet ink according to one aspect of the present invention contains water, titanium oxide, a dispersant, a wetting agent, and a water-soluble polysaccharide having a weight average molecular weight of less than 10,000, and the dispersant contains at least one of sodium carboxymethyl cellulose, sodium alginate, and sodium carbonate.

Effects of the Invention

[0007] According to one aspect of the present invention, it is possible to reduce a decrease in dispersion stability and printing restartability (intermittent restartability), and to reduce a decrease in drying property and a decrease in printing quality even when printing is performed on the surface of a tablet having low permeability.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0009] The edible inkjet ink according to an embodiment of the present invention relates to an inkjet ink used, for example, when printing characters, images, etc. on the surface of a medical tablet, particularly on the surface of a tablet having low permeability, by an inkjet printing method. Hereinafter, the configuration of the inkjet ink according to an embodiment of the present invention and tablets and capsule agents provided with a printed portion printed with the inkjet ink will be described in detail.

[0010] 〔Configuration of Edible Inkjet Ink〕 The edible inkjet ink according to this embodiment contains at least water, titanium oxide as a pigment, a dispersant, a wetting agent, and a water-soluble polysaccharide having a weight average molecular weight of less than 10,000. Further, the dispersant according to this embodiment contains at least one of sodium carboxymethyl cellulose, sodium alginate, and sodium carbonate. With such a configuration, it is possible to reduce a decrease in dispersion stability and printing restartability (intermittent restartability), and even when printing is performed on the surface of a tablet with low permeability, it is possible to reduce a decrease in drying property and a decrease in print quality. Hereinafter, the details of each component will be described.

[0011] (Water) The main solvent contained in the edible inkjet ink according to this embodiment is water, for example, purified water or ion-exchanged water. Note that the above-mentioned "main solvent" means the component having the largest mass ratio in the whole solvent. The proportion of water as the main solvent contained in the edible inkjet ink according to this embodiment is, for example, 50% by mass or more of the whole edible inkjet ink.

[0012] (Titanium Oxide) The titanium oxide used in this embodiment is for food use and is not particularly limited as long as it is in a fine particle state that can be dispersed in the ink. As the titanium oxide particles, those having a crystal structure of anatase type (tetragonal), rutile type (tetragonal), or brookite type (orthorhombic) can be used. The content of titanium oxide in the ink is preferably in the range of 1% by mass or more and 30% by mass or less, more preferably in the range of 10% by mass or more and 20% by mass or less with respect to the mass of the whole ink. If the content of titanium oxide is more than the upper limit value (30% by mass), the printing restartability may decrease, and if it is less than the lower limit value (1% by mass), the color development of the ink may decrease.

[0013] The dispersion average particle diameter (average primary particle diameter) of titanium oxide affects the print restartability due to sedimentation properties within the inkjet head, etc., and thus it may be appropriately set in consideration of this point. Specifically, the dispersion average particle diameter of titanium oxide preferably falls within the range where the median diameter D50 diameter is 30 nm or more and 800 nm or less, more preferably within the range of 50 nm or more and 600 nm or less, and particularly preferably within the range of 100 nm or more and 500 nm or less. Note that when the dispersion average particle diameter of titanium oxide is smaller than 30 nm, both the dispersion stability and the color development property as an ink decrease, and when it is larger than 800 nm, the print restartability may decrease due to precipitation of titanium oxide, etc. The dispersion average particle diameter of titanium oxide may be determined, for example, using the laser diffraction method.

[0014] (Dispersant) The dispersant used in this embodiment contains at least one of sodium carboxymethyl cellulose, sodium alginate, and sodium carbonate. The content of the dispersant is preferably in the range of 0.1 parts by mass or more and 10 parts by mass or less, and more preferably in the range of 1 part by mass or more and 5 parts by mass or less, relative to the mass of titanium oxide which is a pigment. When the content of the dispersant is less than 0.1 parts by mass, titanium oxide cannot be dispersed in water and the print restartability decreases, and when it is more than 10 parts by mass, the viscosity of the ink may increase and the print restartability may decrease.

[0015] (Wetting agent) The wetting agent that can be added to the edible IJ ink according to this embodiment is not particularly limited as long as it is generally added to IJ ink as a wetting agent and can be used. The wetting agent used in this embodiment is preferably one with a high boiling point. Here, "high boiling point" means, for example, 140 °C or higher. Specific examples of the wetting agent used in this embodiment include, for example, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, pentamethylene glycol, trimethylene glycol, 2-butene-1,4-diol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, tripropylene glycol, polyethylene glycol with a number average molecular weight of 2000 or less, 1,3-propylene glycol, isopropyl glycol, isobutylene glycol, glycerin, meso-erythritol, pentaerythritol, 2-pyrrolidone, N-methyl-2-pyrrolidone, and N-ethyl-2-pyrrolidone, etc. Among these wetting agents, a wetting agent containing at least one of propylene glycol and glycerin is particularly preferred. With such a configuration, sufficient print restartability can be imparted to the edible IJ ink. Also, the wetting agent used in this embodiment may be used alone or in combination of two or more.

[0016] The content of the wetting agent is preferably in the range of 20% by mass or more and 50% by mass or less, more preferably in the range of 30% by mass or more and 40% by mass or less, based on the mass of the entire edible IJ ink. If the content of the wetting agent is less than 20% by mass, the drying of the ink is promoted and the print restartability decreases. If it is more than 50% by mass, the viscosity of the ink may increase and the print restartability may decrease.

[0017] (Water-soluble polysaccharides) The water-soluble polysaccharide used in this embodiment is not particularly limited as long as it is water-soluble and has a weight-average molecular weight of less than 10,000. Examples of the water-soluble polysaccharide used in this embodiment include starch substances such as corn and wheat and their enzymatically decomposed products, cellulose-based substances such as carboxymethyl cellulose and hydroxymethyl cellulose, polysaccharides such as sodium alginate, gum arabic, locust bean gum, tragacanth gum, guar gum, and tamarind seeds, and oligosaccharides and disaccharides such as trehalose and isomaltulose. Further, the water-soluble polysaccharide used in this embodiment may contain at least one of maltodextrin, trehalose, and reduced isomaltulose.

[0018] In addition, when the weight-average molecular weight of the water-soluble polysaccharide is 10,000 or more, it may cause an increase in the viscosity of the ink and acceleration of drying, and the print restartability may decrease. Further, the weight-average molecular weight of the water-soluble polysaccharide is preferably 300 or more, and more preferably 1,000 or more. When the weight-average molecular weight of the water-soluble polysaccharide is less than 300, the drying property may deteriorate. Also, the content of the water-soluble polysaccharide is preferably in the range of 0.1% by mass or more and 5% by mass or less with respect to the mass of the entire edible IJ ink. When the content of the water-soluble polysaccharide is less than 0.1% by mass, the print quality may decrease, and when it is more than 5% by mass, the print restartability may decrease. Here, in this embodiment, "water-soluble" means dissolving 0.001 part by mass or more in 1 part by mass of water. The weight-average molecular weight in this embodiment uses the value measured by the GPC method (gel permeation chromatography). Further, in this embodiment, "polysaccharide" refers to a saccharide in which two or more monosaccharides are polymerized.

[0019] 〔Printing method〕 The edible IJ ink according to this embodiment is applicable to commercially available inkjet devices, so it has a wide range of applications and is very useful. Also, in the examples described later, a printing example in a so-called drop-on-demand inkjet using a piezo element (piezoelectric ceramics) as an actuator is shown, but printing may be performed by other methods. For example, as other drop-on-demand inkjet types, there are a thermal inkjet method that discharges the IJ ink by the water vapor pressure generated by instantaneously heating a micro heating element to a high temperature (200 to 300 °C), an electrostatic type that discharges the IJ ink by electrostatic vibration of the actuator, an ultrasonic method that utilizes the cavitation phenomenon of ultrasonic waves, etc. Also, if the IJ ink can be given charge performance, it is also possible to use a continuous jet type (continuous method).

[0020] 〔Target tablets〕 For the edible IJ ink according to this embodiment, it is possible to improve the quality of the printed image applied by the inkjet printing method on the surface of medical tablets and capsules. Examples of the "medical tablets" referred to here include plain tablets (naked tablets), sugar-coated tablets, enteric-coated tablets, orally disintegrating tablets, etc., and also film-coated tablets in which a water-soluble surface layer is formed on the outermost surface of the tablet. Examples of the "medical capsule tablets" include hard capsule tablets and soft capsule tablets. Hard capsule tablets and soft capsule tablets are composed of, for example, a cylindrical body and a cap, and mainly contain powder or granular contents, either as they are or mixed with several types of powders, and are filled into a body made of gelatin or a plant-derived raw material and capped.

[0021] Hereinafter, the configuration of a medical tablet provided with a printed image (printed part) printed with the edible IJ ink according to the embodiment will be described. Figs. 1(a) and (b) are a plan view showing a first configuration example of a medical tablet according to the present embodiment, and a cross-sectional view obtained by cutting this plan view along X1-X'1. The medical tablets shown in Figs. 1(a) and (b) are plain tablets, and an image 9 is printed on the surface of the base 1. This image 9 is an arbitrary image such as, for example, characters, symbols, or barcodes, and is printed by an inkjet printing method using the edible IJ ink according to the present embodiment. Figs. 2(a) and (b) are a plan view showing a second configuration example of a medical tablet according to the present embodiment, and a cross-sectional view obtained by cutting this plan view along X2-X'2. The medical tablets shown in Figs. 2(a) and (b) are film-coated tablets, and an image 9 is printed on the surface of the film 5 covering the base 1. The image 9 shown in Figs. 2(a) and (b) is also printed by an inkjet printing method using the edible IJ ink according to the present embodiment, similar to the image 9 shown in Figs. 1(a) and (b).

[0022] The active ingredient contained in the medical tablet is not particularly limited. For example, substances effective for the prevention and treatment of various diseases (e.g., substances having sleep-inducing action, tranquilizer activity, antibacterial activity, antihypertensive action, antianginal activity, analgesic action, anti-inflammatory activity, psychotropic action, diabetes treatment activity, diuretic action, anticholinergic activity, antihyperacid action, antiepileptic action, ACE inhibitory activity, β-receptor antagonist or agonist activity, anesthetic action, appetite suppressant action, antiarrhythmic action, antidepressant action, anticoagulant activity, antidiarrheal action, antihistamine activity, antimalarial action, antitumor activity, immunosuppressive activity, antiparkinson's disease action, antipsychotic action, antiplatelet activity, antihyperlipidemic action, etc.), substances having a cleaning action, fragrances, substances having a deodorizing action, etc., but are not limited thereto.

[0023] The tablets according to this embodiment can be formulated with a carrier acceptable for its use, together with the active ingredient as necessary. For example, in the case of medical tablets, a pharmaceutically acceptable carrier can be formulated. As the pharmaceutically acceptable carrier, various organic or inorganic carrier substances commonly used as formulation materials are used. For example, excipients, lubricants, binders, disintegrants, thickeners, etc. are formulated in appropriate amounts as needed. Also, additives such as preservatives, antioxidants, colorants, sweeteners, etc. can be used as necessary.

[0024] In this embodiment, medical tablets are taken as an example for explanation, but the present invention is not limited thereto. The printing target of the edible IJ ink according to this embodiment is not particularly limited. For example, it may be printed on the surfaces of various tablets such as feeds, fertilizers, detergents, and foods such as ramune candies. Also, the edible IJ ink according to this embodiment is not particularly limited with respect to the size of the printing target and is applicable to tablets of various sizes. Further, the edible IJ ink according to this embodiment may be used not only for direct printing on the surfaces of the aforementioned tablets but also for direct printing on foods and for packages that directly contact pharmaceuticals and foods.

[0025] Also, the medical tablets in this embodiment are not particularly limited, but particularly, they tend to be highly effective in film-coated tablets having a film coat layer or the like on the surface. This is because, on the surface of the printed tablet, there are fewer voids in the film-coated tablet than in the uncoated tablet, so the ink tends to remain on the tablet surface. Therefore, the edible IJ ink according to this embodiment is more likely to exhibit the effect of quick drying compared to the edible IJ ink according to the prior art.

[0026] (Effect of this embodiment) (1) The edible IJ ink according to this embodiment is an edible IJ ink containing water, titanium oxide, a dispersant, a wetting agent, and a water-soluble polysaccharide having a weight average molecular weight of less than 10,000, and the dispersant contains at least one of sodium carboxymethyl cellulose, sodium alginate, and sodium carbonate. With such a configuration, it is possible to reduce a decrease in dispersion stability and printing restartability (intermittent restartability), and even when printing is performed on the surface of a tablet with low permeability, it is possible to reduce a decrease in drying property and a decrease in print quality.

[0027] (2) Further, the water-soluble polysaccharide having a weight average molecular weight of less than 10,000 contained in the edible IJ ink according to the present embodiment may contain at least one of maltodextrin, trehalose, and reduced isomaltulose. With such a configuration, it is possible to impart sufficient drying property in use and further reduce a decrease in printing restartability. (3) Further, the water-soluble polysaccharide having a weight average molecular weight of less than 10,000 contained in the edible IJ ink according to the present embodiment may be contained in the range of 0.1% by mass or more and 5% by mass or less with respect to the total mass of the edible IJ ink. With such a configuration, it is possible to impart sufficient drying property to the edible IJ ink and further reduce a decrease in printing restartability.

[0028] (4) Further, the titanium oxide contained in the edible IJ ink according to the present embodiment has a median diameter D50 in the range of 30 nm or more and 800 nm or less, and may be dispersed in the edible IJ ink. With such a configuration, it is possible to further reduce a decrease in printing restartability. (5) Further, the wetting agent contained in the edible IJ ink according to the present embodiment may be contained in the range of 20% by mass or more and 50% by mass or less with respect to the total mass of the edible IJ ink. With such a configuration, it is possible to further reduce a decrease in printing restartability.

[0029] (6) Further, the edible IJ ink according to the present embodiment may be used for direct printing on the surface of a tablet, the surface of a soft capsule agent, or the surface of a hard capsule agent, or direct printing on food. With such a configuration, direct printing on the surface of a tablet or the like and direct printing on food become possible, and it can be used for a package that directly touches pharmaceuticals and food. (7) Further, the tablet according to this embodiment includes a printed portion (printed image) printed with the aforementioned edible IJ ink. With such a configuration, it is possible to impart edibility to the printed portion (printed image portion) printed on the surface of the tablet.

[0030] (8) Further, the capsule according to this embodiment includes a printed portion (printed image) printed with the aforementioned edible IJ ink. With such a configuration, it is possible to impart edibility to the printed portion (printed image portion) printed on the surface of the capsule. (9) Further, the tablet according to this embodiment may be a medical tablet. With such a configuration, it is possible to impart edibility to the printed image portion printed on the surface of the medical tablet. (10) Further, the capsule according to this embodiment may be a medical capsule. With such a configuration, it is possible to impart edibility to the printed image portion printed on the surface of the medical capsule.

[0031] [Examples] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples in any way. (Manufacture of Edible IJ Ink) Hereinafter, the preparation procedure of the edible IJ ink will be described. First, the edible IJ ink was prepared. The ink according to this example contains water, titanium oxide, a dispersant, a wetting agent, and a water-soluble polysaccharide having a weight average molecular weight of less than 10,000. Hereinafter, the preparation order of the ink will be described. First, a dispersant and titanium oxide were added to water. Then, the mixed solution containing water, the dispersant, and titanium oxide was put into a paint shaker which is a dispersing machine and refined and dispersed for 1 to 3 hours to prepare a dispersion. Next, a wetting agent and a water-soluble polysaccharide were added to the dispersion as necessary and dispersed to prepare the ink.

[0032] Note that the water used in the ink was ion-exchanged water, and propylene glycol (PG) was used as the wetting agent. Also, the maltodextrin used in this example was in the range of DE value 17 to 19 manufactured by Matsutani Chemical Industry Co., Ltd. Thus, 59 types of edible IJ inks of Examples 1 to 52 and Comparative Examples 1 to 7 were prepared as inks with different components. Their compositions are shown in Tables 1 to 4. Note that the dispersant contained in the edible IJ inks of Examples 1 to 52 included at least one of sodium carboxymethyl cellulose, sodium alginate, and sodium carbonate. Further, the content rate of the dispersant contained in the edible IJ inks of Examples 1 to 52 was 0.01 to 0.1 times the content rate of the pigment.

[0033] Next, 59 types of inks with different components were each passed through a membrane filter to remove solid foreign matters in the liquid. Specifically, each purified ink was obtained by passing through a membrane filter with a diameter of 5.0 μm (cellulose acetate membrane) once and then passing through a membrane filter with a diameter of 0.8 μm (cellulose acetate membrane) once. Note that for water-soluble polysaccharides, as the molecular weight increases, it becomes difficult to obtain a material with a narrow molecular weight distribution. Therefore, in this example, for water-soluble polysaccharides, those with a weight average molecular weight of "1,000 to 9,000", "2,000 to 4,000", and "10,000 to 30,000" were used.

[0034]

Table 1

[0035]

Table 2

[0036]

Table 3

[0037]

Table 4

[0038] In this example, for each edible IJ ink of Examples 1 to 52 and Comparative Examples 1 to 7, evaluations were conducted on dispersion stability, print restartability, transfer resistance, and the print streaks of the printed matter. Tables 1 to 4 show the results of each evaluation. Also, the evaluation method in this example is as follows.

[0039] (1) Evaluation of dispersion stability Each edible IJ ink of Examples 1 to 52 and Comparative Examples 1 to 7 was left standing at 40°C for 14 days, and the median diameter of titanium oxide, which is a pigment, was measured. An increase in the median diameter means that the pigment particles are aggregated, indicating low dispersion stability. The evaluation criteria are as follows. ○: No significant change occurred in the median diameter ×: The particle size clearly increased

[0040] The aforementioned "no significant change occurred in the median diameter" means that the increase width of the median diameter after standing at 40°C for 14 days is 10 nm or less with respect to the median diameter immediately after ink preparation. Also, "the particle size clearly increased" means that the increase width of the median diameter exceeds 10 nm. The dispersion stabilities of Examples 1 to 52 were all "○", while those of Comparative Examples 6 to 7 were "×".

[0041] (2) Evaluation of print restartability Using a piezoelectric ceramic-driven drop-on-demand inkjet head with a printing resolution of 600 dpi in the main scanning direction, 600 dpi in the sub-scanning direction (the conveyance direction of the recording medium such as tablets), and a total of 2,656 nozzles, after leaving it for a specified time (15 minutes to 60 minutes) without flushing, a test pattern was printed with a printing drop volume of 6 pl per drop, and it was confirmed that the ink could be ejected without non-ejection from all nozzles. In Tables 1 to 4, as the evaluation result of the print restartability, the standing time during which ink ejection was possible was measured. The evaluation criteria are as follows. ◎: 30 minutes or more and less than 60 minutes ○: 15 minutes or more and less than 30 minutes ×: Less than 15 minutes The print restartability (intermittent restartability) of Examples 1 to 52 was all "○" or "◎", while the print restartability (intermittent restartability) of Comparative Examples 4 to 5 was "×".

[0042] (3) Evaluation of transfer resistance (drying test) Using a piezoelectric ceramic-driven drop-on-demand inkjet head with a printing resolution of 600 dpi in the main scanning direction, 600 dpi in the sub-scanning direction (the conveyance direction of the recording medium such as tablets), and a total of 2,656 nozzles, images were printed on the following tablets with a printing drop volume of 10 pl per drop. 10 seconds after printing, black drawing paper attached to a digital force gauge was brought into contact with the printed tablets at a pressure of 4 to 5 N for 0.4 to 0.5 seconds, and it was confirmed that the printed ink did not transfer. In Tables 1 to 4, as the evaluation result of the transfer resistance (drying property), the density of the transferred ink was visually observed. The evaluation criteria are as follows. ◎: When there is no transfer of ink ○: When the transfer of ink is very slight and difficult to visually confirm ×: When the ink transferred darkly

[0043] The transfer resistance of Examples 1 to 52 was all "○" or "◎", while the transfer resistance (drying property) of Comparative Examples 1 to 3 was "×". · Tablets (film-coated tablets) A tablet type having a coating layer formed by adding polyethylene glycol, titanium oxide pigment, etc. to hydroxypropyl cellulose, hydroxypropyl methyl cellulose, etc. on the surface

[0044] (4) Evaluation of printing streaks On the following two types of soft capsule tablets 1 and 2, a piezoelectric ceramic-driven drop-on-demand inkjet head with a printing resolution of 600 dpi in the main scanning direction, 600 dpi in the sub-scanning direction (the conveyance direction of the recording medium such as tablets), and a total number of nozzles of 2,656 was used, and solid images were printed at a printing drop volume of 10 pl per drop respectively. The obtained printed matter was visually evaluated for printing streaks according to the following criteria. The evaluation criteria are as follows. ◎: The ink on the solid image is uniform and good without streaks ○: Slight streaks are visible in the ink on the solid image, but it is considered to be at a level with no practical problems ×: Clear streaks are visible in the ink on the solid image, and it is at a level that causes practical problems

[0045] The evaluations of the printing streaks of Examples 1 to 52 were all "○" or "◎", while the evaluations of the printing streaks of Comparative Examples 1 to 3 were "×". · Soft capsule tablet 1 (gelatin tablet) A soft capsule tablet having a coating layer of gelatin formed on the surface of the capsule tablet · Soft capsule tablet 2 (HPMC tablet) A soft capsule tablet having a coating layer of hydroxypropyl cellulose, hydroxypropyl methyl cellulose, etc. formed on the surface of the capsule tablet

[0046] From the above results, it can be seen that if it is an edible IJ ink containing water, titanium oxide, a dispersant, a wetting agent, and a water-soluble polysaccharide having a weight average molecular weight of less than 10,000, and the dispersant contains at least one of sodium carboxymethyl cellulose, sodium alginate, and sodium carbonate, it can reduce the decrease in dispersion stability and printing restartability (intermittent restartability), and even when printing is performed on the surface of a tablet with low permeability, it can reduce the decrease in drying property and the decrease in print quality.

Explanation of Signs

[0047] 1 Base 5 Film 9 Image

Claims

1. An edible IJ ink comprising water, titanium oxide, a dispersant, a wetting agent, and a water-soluble polysaccharide having a weight average molecular weight of less than 10,000, wherein the dispersant contains at least one of sodium carboxymethyl cellulose, sodium alginate, and sodium carbonate, and the water-soluble polysaccharide having a weight average molecular weight of less than 10,000 contains dextrin, trehalose, or reduced isomaltulose in the range of 0.1% by mass or more and 6% by mass or less. The edible IJ ink is characterized by this.

2. The edible IJ ink according to Claim 1, wherein the water-soluble polysaccharide having a weight average molecular weight of less than 10,000 is contained in the range of 0.1% by mass or more and 5% by mass or less with respect to the total mass of the edible IJ ink.

3. The edible IJ ink according to Claim 1 or Claim 2, wherein the titanium oxide has a median diameter D50 in the range of 30 nm or more and 800 nm or less and is dispersed in the edible IJ ink.

4. The edible IJ ink according to any one of Claims 1 to 3, wherein the wetting agent is contained in the range of 20% by mass or more and 50% by mass or less with respect to the total mass of the edible IJ ink.

5. The edible IJ ink according to any one of Claims 1 to 4, which is used for direct printing on the surface of tablets, soft capsules, or hard capsules, or for direct printing on foods.

6. A tablet comprising a printed portion printed with the edible IJ ink according to any one of Claims 1 to 5.

7. A capsule comprising a printed portion printed with the edible IJ ink according to any one of Claims 1 to 5.

8. The tablet according to Claim 6, which is a medical tablet.

9. The capsule according to Claim 7, which is a medical capsule.

Images