TW202409217A - alkaline tablets - Google Patents

Abstract

The present invention provides an ink suitable for printing alkaline tablets, a method for manufacturing printed tablets using the ink, and a tablet printing device. The ink of the embodiment is an inkjet ink for printing identification information on alkaline tablets in blue or a color including blue, and contains at least Edible Blue No. 1 and shellac.

Description

Alkaline tablets

Embodiments of the present invention relate to an ink, a method for manufacturing printed tablets using the ink, and a tablet printing device.

Printing identification information such as characters or marks on tablets improves the tablet's visibility, thereby preventing pharmacists from making medication errors or users from accidentally ingesting the tablets.

As a printing method for tablets, inkjet printing can be cited. Inkjet printing can print on tablets in a non-contact manner, so for example, tablets with a high possibility of disintegration, such as OD (orally disintegrating) tablets, can also be printed appropriately.

In this type of inkjet printing, ink containing a dye (dye ink) is sometimes used. Dye ink makes it easier to display the printed text and the like in a darker color than ink containing a pigment, and the visual recognition of the identified information becomes better. In addition, since the ink containing a pigment is in a state where the pigment is dispersed in a solvent, the ejection property from the nozzle of the inkjet head is poor, and sometimes it causes poor ejection, resulting in poor printing. On the other hand, in dye ink, since the dye is dissolved in the solvent, it is easy to ensure the ejection property from the nozzle of the inkjet head, and poor printing can be suppressed. [Prior art literature] [Patent literature]

[Patent Document 1] Japanese Patent Publication No. 2011-236279

[The problem that the invention wants to solve]

The purpose of the present invention is to provide an ink suitable for printing alkaline tablets, a method for producing printed tablets using the ink, and a tablet printing device. [Means for solving the problem]

The ink of the embodiment of the present invention is an inkjet ink for printing identification information on alkaline tablets, and comprises: at least edible blue No. 1 pigment, insect glue, water, and ethanol.

The method for producing a tablet according to an embodiment of the present invention is characterized in that the ink is supplied to a print head that ejects the ink from a nozzle, and identification information is printed on an alkaline tablet using the ink according to the embodiment using the print head.

A tablet printing device according to an embodiment of the present invention is characterized by having: a conveying device that conveys alkaline tablets; and a print head that ejects ink from a nozzle to the alkaline tablet conveyed by the conveying device. To perform printing, the print head ejects the ink of the embodiment.

In inkjet printing, ink filled in an inkjet head is ejected from an opening located at a nozzle at the front end of the inkjet head. If the ink dries and adheres to the opening of the nozzle or around the opening, and the shape of the opening is deformed or clogged, it may lead to poor ejection. In addition, if the viscosity of the ink is high, it will not be ejected normally from the nozzle, resulting in poor ejection. On the surface of the tablet to be printed, droplets of ink ejected from the nozzles of the inkjet head land, and small printing dots (dots) (dots) formed by the landing droplets are combined to form dots. Draw to print words or symbols, etc. At this time, if there is an ejection failure, printing dots will not be formed in the pattern of characters or symbols, and the printing will look blurry, or the desired characters or symbols will not be visible, resulting in printing defects.

Furthermore, if it is difficult to dry the ink that has landed on the tablet surface, the ink may peel off during transportation after printing, or may adhere to other tablets, transportation equipment, etc., causing contamination. Therefore, as characteristics of an inkjet ink used for tablet printing, it is necessary to have both ejection properties from a nozzle and drying properties after printing.

Tablets include those that contain alkaline raw materials or are coated with alkaline ingredients so that their surfaces (at least the printed object portion) show alkalinity (hereinafter referred to as "alkaline tablets"). It is known that if alkaline tablets are printed using dye ink, the printed text, etc., will change color or bleed over time depending on the dye.

In particular, when printing alkaline tablets using ink containing food blue No. 1 (brilliant blue FCF), which is widely used as a blue dye, in a blue ink, the printed identification information changes color to light purple within 1 to 2 days and bleeds when stored in an environment of 40 degrees and 75% RH. That is, since it changes to a color different from the color immediately after printing or the desired color (specified color), the impression of a company logo or illustration containing blue is changed. In addition, when printing text, the text becomes unclear due to the bleed, and the identification of the tablet is reduced.

Therefore, the inventors of the present application invented an ink that can appropriately print identification information on alkaline tablets even when edible blue No. 1 is used as a pigment.

[Ink] The ink of the present embodiment is described. The ink of the present embodiment is an inkjet ink, particularly a blue ink suitable for printing alkaline tablets. The ink contains at least edible blue No. 1 as a pigment and at least insect glue as a resin. In addition, emulsifiers, flavoring agents, preservatives, etc. may be formulated as needed. When preparing the ink, it is preferred to use edible compositions such as compositions approved by the Japanese Pharmacopoeia or the Food Additives Code as each composition.

(pigment) The ink of this embodiment contains at least Food Blue No. 1 (Brilliant Blue FCF) as a pigment. In addition, it is more preferable to contain Gardenia Blue pigment together with Edible Blue No. 1.

The ink of this embodiment may be only Edible Blue No. 1, or only Edible Blue No. 1 and Gardenia Blue pigment, and further, by using not only Edible Blue No. 1 or Gardenia Blue pigment but also other The pigment can also be adjusted to blue or a desired color including blue. As other pigments, one or more types of pigments may be selected from conventionally known synthetic food pigments and natural food pigments. In addition, the color including blue is, for example, a color including blue as a color component, such as green or purple.

Examples of synthetic food colorings include tar-based colorings, natural coloring derivatives, natural synthetic colorings, and titanium dioxide. Examples of tar-based colorings include: food red No. 2, food red No. 3, food red No. 40, food red No. 102, food red No. 104, food red No. 105, food red No. 106, food yellow No. 4, food yellow No. 5, food blue No. 2, food red No. 2 aluminum starch, food red No. 3 aluminum starch, food red No. 40 aluminum starch, food yellow No. 4 aluminum starch, food yellow No. 5 aluminum starch, food blue No. 2 aluminum starch, and examples of natural coloring derivatives include copper chlorophyllin, sodium copper-chlorophyllin, potassium norcarmine, and so on. As natural synthetic pigments, there are β-carotene, riboflavin, etc.

Examples of natural food pigments include plant carbon pigments, anthocyanin pigments, carotenoid pigments, quinone pigments, flavonoid pigments, betaine pigments, and monascus. Pigments and other pigments derived from natural products. Examples of anthocyanin pigments include: carrot pigment, red cabbage pigment, red rice pigment, elderberry pigment, cowberry pigment, gooseberry pigment, and cranberry. Pigment, salmon berry pigment, perilla pigment, thimbleberry pigment, strawberry pigment, dark sweet cherry pigment, cherry pigment, hibiscus pigment, huckleberry pigment, Grape juice pigment, grape peel pigment, black currant pigment, blackberry pigment, blueberry pigment, plum pigment, whortleberry pigment, boysenberry pigment, mulberry pigment , purple sweet potato pigment, purple corn pigment, purple potato pigment, raspberry pigment, red currant pigment, loganberry pigment, and other anthocyanin pigments. Examples of carotenoid pigments include annatto pigments, gardenia yellow pigments, and other carotenoid pigments. Examples of quinone pigments include cochineal pigments, purple root pigments, shellac pigments, and other quinone pigments. Examples of flavonoid pigments include safflower yellow, sorghum pigment, onion pigment, and other flavonoid pigments. Examples of betaine-based pigments include betalain pigments. Examples of red yeast rice pigments include red yeast rice pigments and red yeast rice yellow pigments. Examples of other pigments derived from natural products include curcumin, gardenia red pigment, spirulina blue pigment, and the like.

The content of the pigment is preferably 0.1% to 10% by weight, more preferably 0.5% to 8% by weight, relative to the total weight of the ink composition. If the content of the pigment is less than 0.1% by weight, the printed color is light and the visual recognition is poor. In addition, if it is more than 10% by weight, the ink viscosity increases and the ink cannot be ejected normally, resulting in poor printing.

(Resin) By adding a resin component to the ink, the adhesion of the ink to the tablet can be improved, and at the same time, after being printed on the tablet, it is dried to form a film, so that the abrasion resistance can be obtained. In the ink of the present embodiment, insect glue is used as the resin. The so-called insect glue is a resin obtained by purifying the resin-like substance secreted by the lac insect, and is a mixture of various resin esters, waxes, pigments, etc. When mixing it into the ink, it is preferred to use white insect glue that has been bleached or refined insect glue that has been treated to remove pigments or wax. In addition, by mixing insect glue into the ink, the viscosity of the ink can be increased, so that it can be adjusted to a viscosity suitable for ejection from the nozzle using an inkjet head.

The content of shellac is preferably 0.5% by weight to 10% by weight, more preferably 1% by weight to 8% by weight, based on the entire ink composition. If the content of shellac is less than 0.5% by weight, when alkaline tablets are printed and stored in an environment with a temperature of 40 degrees and a humidity of 75% RH, the printed identification information will change color within 1 to 2 days. It is lavender and bleeds. In addition, if the content exceeds 10% by weight, the ink will not be ejected normally due to an increase in the viscosity of the ink, resulting in poor printing.

(pH adjuster) It is known that shellac is soluble in alkaline aqueous solutions in addition to alcohols. By making the ink alkaline, the shellac can be maintained in a dissolved state without precipitating. As the pH adjuster, those approved as food additives are preferred. In order to obtain water resistance after printing ink containing shellac, it is preferable to use a component that volatilizes when the ink dries, and for example, ammonium carbonate or ammonium bicarbonate can be used. The pH of the ink is preferably 6.5 to 10.

(Ethanol) Ethanol is preferably naturally brewed fermented ethyl alcohol or sugarcane alcohol. The ethanol content is preferably 5% to 60% by weight, more preferably 10% to 40% by weight, relative to the total composition of the ink. If the ethanol content is less than 5% by weight, the ink will have poor drying properties. For example, since drying takes more than 3 seconds after printing, the ink will peel off during transportation after printing, or adhere to other tablets or conveying devices, etc., causing contamination. In addition, the surface tension of the ink increases, and the printed ink is easy to bounce onto the surface of the tablet. That is, since it does not infiltrate and diffuse on the surface of the tablet, it is difficult to dry, and the contact area with the surface of the tablet is small, so the adhesion becomes small, for example, it will peel off even if it is wiped after 24 hours. In addition, if it is more than 60% by weight, the ink will dry and adhere inside or around the opening of the inkjet nozzle, clogging the opening, resulting in poor ejection or deviation in the flying direction of the ejected ink, leading to poor printing.

(Water-soluble high boiling point organic solvent) Water-soluble high-boiling point organic solvents are used to prevent the nozzles of the inkjet heads from drying out. As the water-soluble high-boiling point organic solvent, for example, one or more types may be selected from propylene glycol and glycerin. The content of the water-soluble high-boiling organic solvent is preferably 1 to 60% by weight, and more preferably 2 to 55% by weight relative to the entire ink composition. If the water-soluble high-boiling point organic solvent is less than 1% by weight, the ink in the inkjet nozzle dries, resulting in poor printing. In addition, if the content exceeds 60% by weight, the ink will not be ejected normally due to an increase in the viscosity of the ink, resulting in poor printing.

(emulsifier) The emulsifier can be selected from one or two water-soluble substances among lecithin, glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, and polyoxyethylene sorbitan fatty acid ester. above. The emulsifier does not necessarily need to be blended, but when blended, the content of the emulsifier is preferably 0.01% to 5% by weight, and more preferably 0.1% to 2% by weight relative to the entire ink composition. If the content is less than 0.01% by weight, the surface tension of the ink becomes large and the nozzle opening may not be in an appropriate meniscus state. Therefore, the ink will not be ejected from the nozzle, or even if it is ejected, it will not land on the ink. Specify the position, resulting in poor printing. In addition, if the content exceeds 5% by weight, the ink may thicken, or precipitates may be generated over time, causing clogging of the nozzles, resulting in printing defects.

(Manufacture of ink) Next, this embodiment will be specifically described using the Examples and Comparative Examples shown in Table 1. However, these Examples are examples and are not limited to these Examples.

Examples 1 to 3 and Comparative Examples 1 and 2 are prepared by mixing the compositions shown in Table 1 at the mixing ratios shown in Table 1. In addition, the mixing ratios shown in Table 1 are expressed by weight percentage relative to the entire composition of the ink. Examples 1 to 3 are inks mixed with edible blue No. 1 and insect glue. Comparative Example 1 is an ink mixed with edible blue No. 1 as a pigment (without insect glue), and Comparative Example 2 is an ink mixed with lilac pigment as a pigment.

In addition, since Comparative Example 1 does not contain insect glue, the ratio of propylene glycol is increased to adjust the viscosity to be appropriate when printing using an inkjet head. In Comparative Example 2, since the indigo pigment is dissolved, the ratio of purified water is high and the ratio of ethanol is low compared to other examples or comparative examples.

The preparation operation is as follows. First, all the components except the pigment shown in Table 1 are stirred while being heated to 50°C to dissolve. After each component is dissolved, the pigment shown in Table 1 is mixed and further stirred at 50°C for 1 hour. Thereafter, the mixture is left to stand for 1 hour, cooled to room temperature, and filtered to prepare the ink.

In addition, the mixed pigment may be maintained in a powder state, or may be in the form of a solution dissolved in a liquid such as water or a paste dispersed in a liquid such as water. Ultimately, as long as the pigment is evenly dissolved or mixed.

[Table 1] Composition Embodiment 1 Embodiment 2 Embodiment 3 Comparison Example 1 Comparison Example 2 pigment Edible Blue No. 1 2.0 2.0 2.0 2.0 - Blue pigment - 2.0 1.0 - 10.0 Resin Insect Glue 7.0 7.0 7.0 - - pH Adjuster Ammonium carbonate 0.8 0.8 0.8 - - water Refined water 39.2 47.2 38.7 32.5 79.0 Organic solvents Ethanol 25.0 20.0 25.0 10.0 5.0 glycerin - - - - 2.0 Propylene glycol 25.0 20.0 25.0 55.0 - Emulsifier Glyceryl fatty acid esters - - 0.5 0.5 - Sucrose fatty acid esters - 1.0 - - - Polyoxyethylene sorbitan fatty acid esters 1.0 - - - 4.0 Total 100.0 100.0 100.0 100.0 100.0 Evaluation characteristics Sprayability of self-spraying nozzles ○ ○ ○ ○ × Lightfastness of printing ○ ○ ○ ○ × Stability of printing over time △ ○ ○ × ○

(Evaluation of ink) The inks of Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated for their ejection properties from the nozzles using an inkjet head. Furthermore, the lightfastness and stability of the printed text were evaluated for the printed text on tablets as the printed object (each evaluation method will be described later). In each evaluation, an OD sheet containing magnesium oxide as the main component, which is a type of alkaline tablet, was used as the printing object. The results are shown in Table 1.

<Evaluation of the jetting performance of the self-jet nozzle> Regarding the jetting performance of the self-jet nozzle, the inkjet head was filled with ink and left for 15 minutes, and then a printing test was performed to visually check whether there was any printing defect. 0: Each printed dot can be formed at the specified position. ×: There is a defect in the printed dot, or (/and) each printed dot does not fall at the specified position.

<Evaluation of light resistance of printed characters> After printing, the tablets were exposed to 1000 lux for 50 days without packaging, and the printed characters were visually checked for fading. 0: No fading of printed characters was observed. ×: The printed characters were faded.

＜Evaluation of printing stability over time＞ Regarding the stability of printing over time, the printed tablets were stored for two weeks in an environment of 40°C and 75% RH, and the presence of bleeding of the text and color changes was visually confirmed by comparing the tablets immediately after printing. 〇: No bleeding and no discoloration. △: The color changes slightly to a color different from the desired color. or/and) color bleeding is found to the extent that there is no problem with the visual legibility of the printed text. ×: The color changes to a color different from the desired color. Or/and the printed text bleeds, making it difficult to read.

(Results) As can be seen from the experimental results of Examples 1 to 3 shown in Table 1, the ink using Food Blue No. 1 as a pigment and blended with insect glue as a resin is an ink having excellent light resistance and moisture resistance when used for printing on alkaline tablets. Furthermore, the ink blended with not only Food Blue No. 1 but also indigo pigment as a pigment is particularly good. The results are described in more detail below.

<Example 1> The ink of Example 1 contains edible blue No. 1 as a pigment and insect glue as a resin. The ink of Example 1 was filled in the inkjet head and printed, and each printed small dot was formed at a predetermined position. In the light fastness evaluation, the color of the printed characters printed on the alkaline tablets did not change from that just after printing. In the time stability evaluation, the blue color became slightly lighter, and although slight bleeding was found, it was at a level that was not a problem in visual recognition.

<Example 2> The ink of Example 2 contains not only food blue No. 1 but also indigo pigment as a pigment, and contains insect glue as a resin. The ink of Example 2 is filled in the inkjet head and printed, and each printed small dot is formed at a specified position. In the light resistance evaluation, the color of the printed characters printed on the alkaline tablets did not change from that just after printing. In the time stability evaluation, no discoloration or bleeding over time was found, and the printed characters could be read well.

<Example 3> The ink of Example 3 also contains not only Food Blue No. 1 but also Amaranth pigment as the pigment, similar to Example 2. The ink of Example 3 was filled in the inkjet head and printed, and each printed small dot was formed at a predetermined position. In the light fastness evaluation, the color of the printed characters printed on the alkaline tablets did not change from that just after printing. In the time stability evaluation, no time-dependent discoloration or bleeding was found, and the printed characters could be read well.

＜Comparative example 1＞ The ink of Comparative Example 1 contains Edible Blue No. 1 as a pigment and does not contain a resin component. The ink of Comparative Example 1 was filled into the inkjet head and printed. As a result, each printed dot was formed at a predetermined position. In the light fastness evaluation, there was no change in the color ratio of the characters printed on the alkaline tablets from those immediately after printing. However, in the time-lapse stability evaluation, the printed characters changed color to lavender in about 1 to 2 days. Furthermore, bleeding of printed characters occurs, making it difficult to read the printed characters.

<Comparative Example 2> The ink of Comparative Example 2 is an ink containing agaric blue pigment as a pigment and does not contain a resin component. For natural pigments such as agaric pigment, a large amount of agaric pigment needs to be formulated in order to obtain a sufficient concentration for printing. In the ink of Comparative Example 1, agaric pigment is formulated in an amount sufficient for visual recognition of the printed characters, resulting in a high viscosity of the ink and poor sprayability from the nozzle. In addition, in the composition shown in Comparative Example 2, the concentration of blue is also lighter than that of Example 1. In the light resistance evaluation, the printed characters faded and almost disappeared. In the time stability evaluation, no bleeding or discoloration of the printed characters was found.

(Summary) According to the results described above, when printing is performed by inkjet printing, the ink prepared with edible blue No. 1 and insect glue has stable ejection from the nozzle, thereby suppressing the occurrence of printing defects. Furthermore, the ink has high light resistance and stability over time, which can suppress the discoloration of the printed identification information. In addition, the bleeding of printing can also be suppressed. Therefore, after printing, the identification information can be easily identified even after the tablet is stored, and mis-prescription or mis-ingestion can be prevented.

Compared with inks without resin components, inks containing insect glue also have excellent light resistance and stability over time. The reason is that by mixing insect glue, the printed ink dries and forms a film on the tablet, and the pigment of Food Blue No. 1 is not easily affected by decomposition by the alkali of the alkaline tablet. In addition, because insect glue is a resin with acid, it has a neutralizing effect with the alkaline tablet, which is believed to minimize the effect of the alkali on the pigment. Food Blue No. 1 is a pigment that is generally widely used and has excellent color development, but it is not suitable for use when printing on alkaline tablets because of its low stability over time. In contrast, by mixing insect glue, Edible Blue No. 1 can be used for printing alkaline tablets.

In addition, in the past, among inkjet inks used for printing tablets, inks containing shellac were mostly inks with a high ethanol content (for example, about 60% by weight relative to the entire ink composition). ). If the ethanol content is high, it may cause printing defects as described above. If the dissolution of shellac in an alkaline aqueous solution is utilized, and the solvent of the ink is adjusted to be alkaline using, for example, the above-mentioned pH adjuster, it is possible to prepare ink in which shellac is dissolved even if the ethanol content is suppressed.

Furthermore, it is more preferable to mix not only Edible Blue No. 1 but also gardenia blue pigment as a pigment. By blending Edible Blue No. 1 and Gardenia Blue pigments, the stability over time of the ink can be further improved compared to the case where the pigment is Edible Blue No. 1 alone. Comparing the results of Example 1 with Example 2 and Example 3 also makes this clear. Comparing the results of Comparative Example 1 with Comparative Example 2 also shows that the ink containing gardenia blue pigment has excellent stability over time. . That is, it is thought that by blending not only Edible Blue No. 1 but also gardenia blue pigment, the stability over time can be compensated.

[Tablet printing device] When printing identification information on tablets, a tablet printing device can be used. The tablet printing device includes a conveyor and an inkjet printing head. The conveying device is, for example, a suction conveying device that conveys the tablets while suctioning and holding them. The print head is arranged to face the conveying surface of the conveying device, ejects ink from the nozzle toward the tablet passing under the print head, and prints identification information on the tablet. By supplying the above-mentioned ink containing at least Edible Blue No. 1 and shellac to the print head of the tablet printing device, and printing the conveyed alkaline tablets, the alkaline tablets can be printed. Print identification information in blue or colors including blue.

[Other embodiments] In the ink, additives such as spices, preservatives (bacteriostats), defoaming agents, and surfactants can also be mixed as needed. Of course, when the printed object is medicine, food, etc., it is only necessary to select edible substances. In addition, when mixing each composition of the ink, pre-processing or post-processing such as heating may be performed.

For stirring during the preparation of the ink, a commonly used stirrer such as a magnetic stirrer or a propeller stirrer can be used.

In addition, the ink may also contain so-called pigments such as plant carbon powder, titanium dioxide, and aluminum pigment. When preparing the ink containing the pigment, the pigment needs to be dispersed. The dispersion process is not particularly limited as long as it is a commonly used disperser. Specifically, a ball mill, a roller mill, a sand mill, a bead mill, etc. may be mentioned.

There is no particular limitation on the method of filtering the ink, and centrifugal filtration, screening process filtration, etc. may be used.

As the tablet, as long as at least the printing target part is alkaline, it can include tablets used for medical purposes, dietary purposes, cleaning purposes, industrial purposes or aromatic purposes. In addition, as a tablet, in addition to the bare tablet (uncoated tablet) or film-coated tablet (film-coated tablet), there are also sugar-coated tablets, enteric tablets, gelatin outer-coated tablets, multi-layer tablets, core tablets, etc., and various capsule tablets such as hard capsules or soft capsules can also be included in the tablet. Furthermore, as the shape of the tablet, there are various shapes such as disc or lens, triangle, ellipse, etc. In addition, when the tablet as the printing target is for medical use or dietary use, the composition of the ink used is preferably edible, but of course, in the case of not being the case, it can also be an inedible composition.

The embodiments of the present invention are described above, but the embodiments are only examples and are not intended to limit the scope of the invention. The novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or their variations are included in the scope or the subject matter of the invention, and are included in the invention described in the scope of the patent application and its equivalent.

Claims (8)

An alkaline tablet characterized by: Having identification information of blue or colors including blue printed with ink, The ink contains: A pigment containing at least 0.1% to 10% by weight of Food Blue No. 1 (Brilliant Blue FCF) relative to the entire ink composition; resin, containing at least shellac; water; 5% to 60% by weight of ethanol relative to the entire ink composition; and 1% to 60% by weight of a water-soluble high-boiling point organic solvent relative to the entire ink composition, and The shellac is 0.5% by weight to 10% by weight relative to the entire ink composition. The alkaline tablet according to claim 1, wherein the water-soluble high-boiling point organic solvent is at least one selected from the group consisting of propylene glycol and glycerol. The alkaline tablet according to claim 1, further comprising gardenia blue pigment as the pigment. The alkaline tablet according to claim 1 is a tablet which contains an alkaline raw material and exhibits alkalinity on the surface, or a tablet which is coated with an alkaline component and exhibits alkalinity on the surface. The alkaline tablet according to claim 1, wherein the shellac is white shellac that has been bleached, or refined shellac that has been subjected to a removal process to remove pigments or waxes. The alkaline tablet as described in claim 1, wherein the ink further comprises a pH adjuster, the pH adjuster is ammonium carbonate or ammonium bicarbonate. The alkaline tablet as described in claim 1, wherein the ink further comprises an additive, and the additive is one or more of a fragrance, a preservative (antibacterial agent), a defoaming agent, and a surfactant. The alkaline tablet according to claim 1, wherein the ink further contains an emulsifier, The emulsifier is one or more of lecithin, glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, and polyoxyethylene sorbitan fatty acid ester.