JP7639039B2 - Ink composition, printed tablet, tablet printing device, and tablet printing method - Google Patents

Description

Embodiments of the present invention relate to an ink composition, a printed tablet, a tablet printing device, and a tablet printing method.

By printing identifying information such as letters or symbols on the surface of tablets for internal or oral use, the tablets can be more easily identified, preventing dispensing errors by pharmacists and incorrect dosing by users.

Dye inks that contain dyes are sometimes used for printing on tablets. Compared to inks that contain pigments, dye inks tend to produce darker printed characters and improve the visibility of identification information.

JP 2013-122401 A

However, inks that contain dyes as colorants have the disadvantage that they are less lightfast than inks that contain pigments, and are more likely to fade when exposed to light.

The problem that the present invention aims to solve is to provide an ink composition, a printed tablet, a tablet printing device, and a tablet printing method that can suppress fading due to light.

The ink composition according to the embodiment contains a dye, water, and ethanol, and contains Food Red No. 104 and Food Red No. 3 as the dye , and the ratio of Food Red No. 3 to Food Red No. 104 is 0.05 or more and 5 or less in weight ratio .

The printed tablet according to the embodiment has identification information printed on its surface using the ink composition according to the embodiment.

The tablet printing device according to the embodiment includes an ink supply unit capable of supplying the ink composition according to the embodiment, a transport unit that transports tablets, a detection unit that detects the tablets transported by the transport unit, and an inkjet head that ejects the ink composition supplied by the ink supply unit onto the tablets detected by the detection unit.

The tablet printing method according to the embodiment supplies the ink composition according to the embodiment to an inkjet head, transports tablets using a transport unit, detects the tablets transported by the transport unit, and ejects the ink composition from the inkjet head onto the detected tablets.

According to an embodiment of the present invention, fading due to light can be suppressed.

FIG. 1 is a diagram showing the structural formulas of Food Red No. 104 and Food Red No. 3 contained in the ink composition according to an embodiment. FIG. 2 is a diagram showing an example of a printed tablet having identification information printed on its surface using the ink composition according to the embodiment. FIG. 3 is a schematic diagram illustrating an example of a configuration of a tablet printing device according to an embodiment. FIG. 4 is a graph showing the relationship between the amount of Food Red No. 3 blended in the ink compositions according to Examples 1 to 9 and Comparative Examples 1 to 4 and the color difference ΔE before and after the lightfastness test.

[Embodiment]
Hereinafter, an ink composition, a printed tablet, a tablet printing device, and a tablet printing method according to embodiments will be described with reference to the drawings.

(Examples of Ink Composition)
The ink composition of the embodiment is used, for example, for printing on tablets or coloring edible objects, and contains a dye, water, and ethanol, and contains Food Red No. 104 and Food Red No. 3 as dyes. Figure 1 shows the structural formulas of Food Red No. 104 and Food Red No. 3.

Figure 1 shows the structural formulas of Food Red No. 104 and Food Red No. 3 contained in the ink composition according to the embodiment. Figure 1(a) shows the structural formula of Food Red No. 104, and Figure 1(b) shows the structural formula of Food Red No. 3.

Food Red No. 104 (Phloxine) and Food Red No. 3 (Erythrosine) are a type of synthetic coloring agent known as edible tar-based dyes. More specifically, Food Red No. 104 and Food Red No. 3 are xanthene acid dyes that have a xanthene skeleton. Xanthene acid dyes are also called xanthene pigments.

Food Red No. 104 and Food Red No. 3 are usually handled in powder form and can be used to color objects pink (peach).

The ink composition of the embodiment contains, for example, only Food Red No. 104 and Food Red No. 3 as dyes. In other words, the total blend ratio of Food Red No. 104 and Food Red No. 3 in the dyes contained in the ink composition may be 100%.

The ratio of Food Red No. 3 to Food Red No. 104 is, for example, a weight ratio of 0.05 or more and less than 9, preferably 0.1 or more and 5 or less, and more preferably 0.25 or more and 0.5 or less.

In other words, the ratio of Food Red No. 104 to Food Red No. 3 is, for example, 1:0.05 to 1:9 (the ratio for Food Red No. 3 includes 0.05 but does not include 9), preferably 1:0.1 to 1:5 (the ratio for Food Red No. 3 includes 0.1 and 5), and more preferably 1:0.25 to 1:0.5 (the ratio for Food Red No. 3 includes 0.25 and 0.5).

For example, when printing identification information on tablets, fading of the dye contained in the ink composition becomes an issue in order to maintain the visibility of the printed identification information. Dyes such as Food Red No. 104 and Food Red No. 3 generally have low light resistance and are easily faded by light.

In addition, when comparing Food Red No. 104 and Food Red No. 3, Food Red No. 104 has better light resistance than Food Red No. 3. However, neither Food Red No. 104 nor Food Red No. 3 alone has the light resistance required for tablet printing applications.

As mentioned above, by mixing Food Red No. 104 with Food Red No. 3 in a specified ratio, an ink composition that has high light resistance and is resistant to fading can be obtained.

The blending ratio of the dye in the ink composition of the embodiment is, for example, 0.1% by weight or more and 10% by weight or less, and more preferably 0.5% by weight or more and 8% by weight or less. If the dye content is less than 0.1% by weight, the color when printed will be light and visibility will be reduced. If the dye content is more than 10% by weight, the viscosity of the ink composition will increase, and the ink composition may not be ejected normally when printing, for example, by the inkjet method described below, resulting in poor printing.

The water and ethanol contained in the ink composition of the embodiment are, for example, solvents that dissolve the above-mentioned dyes.

For example, purified water can be used as the water. Purified water is water from which at least any impurities such as mineral components, residual chlorine, and microorganisms have been removed, and which is obtained by treating ordinary water such as tap water using a system that uses ion exchange, distillation, reverse osmosis, or ultrafiltration, either alone or in combination.

As ethanol, for example, fermented ethyl alcohol from natural brewing or sugar cane alcohol can be used.

The ink composition of the embodiment is obtained by dissolving a powder, an aqueous solution, or a paste of Food Red No. 104 and Food Red No. 3 in a mixture of water and ethanol. When mixing these various components, pre-treatment or post-treatment such as heating may be performed.

The ink composition of the embodiment prepared as described above can color an object pink (peach). When the color tone of the ink composition of the embodiment is expressed in the L ^* a ^* b ^* color system, the ink composition of the embodiment is supplied to an inkjet head and printed in a solid manner so that 0.45 mg of the ink composition is uniformly distributed per square centimeter, and the object is colored in the following color range, for example.

L ^* value: 56 or more and 94 or less
a ^* value: 23 or more and 79 or less
b ^* value: -33 or more and 21 or less

Here, the L ^* value represents lightness in the range of 0 to 100, with a larger L ^* value indicating higher lightness (brightness). The ^a* and b ^* values each represent chromaticity in the range of -100 to 100, with a color being achromatic when both the a ^* and b ^* values are zero. The ^a* value indicates a stronger reddish tinge as it moves in the positive direction, and a stronger greenish tinge as it moves in the negative direction. The b ^* value indicates a stronger yellowish tinge as it moves in the positive direction, and a stronger blueish tinge as it moves in the negative direction.

In addition, the light resistance of the ink composition of the embodiment can be expressed by a color difference ΔE, which is the difference between the L ^* value, the a ^* value, and the b ^* value before and after a predetermined amount of light is irradiated to a printed matter such as a tablet. The smaller the value of this color difference ΔE, the smaller the color change. In other words, the smaller the value of the color difference ΔE, the better the light resistance of the ink composition and the easier it is to suppress fading. Specifically, the color difference ΔE can be calculated by the following formula.

ΔE=[(ΔL ^* ) ²⁺ (Δa ^* ) ²⁺ (Δb ^* ) ² ] ^1/2 ...(1)

For example, when a printed matter is irradiated with a cumulative ultraviolet/visible light of 1.2 million Lx, the color difference ΔE of the printed matter before and after irradiation with ultraviolet/visible light in the ink composition of the embodiment is, for example, less than the value exhibited by an ink composition containing at least Food Red No. 104 alone as the blended colorant, and is preferably less than 25, and more preferably less than 20.

In addition to the above-mentioned Food Red No. 104 and Food Red No. 3, other dyes can be mixed into the ink composition of the embodiment to adjust the color to a desired color. The other dyes can be selected from, for example, one or more known synthetic food dyes and natural food dyes.

Examples of synthetic food dyes include tar-based dyes, natural dye derivatives, natural synthetic dyes, titanium dioxide, etc.

Examples of tar-based dyes include Food Red No. 2, Food Red No. 40, Food Red No. 102, 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 Lake, Food Red No. 3 Aluminum Lake, Food Red No. 40 Aluminum Lake, Food Yellow No. 4 Aluminum Lake, Food Yellow No. 5 Aluminum Lake, Food Blue No. 2 Aluminum Lake, etc.

Examples of natural pigment derivatives include copper chlorophyll, sodium copper chlorophyllin, and potassium norbixin, and examples of natural synthetic pigments include beta-carotene and riboflavin.

Other pigments include natural food pigments, such as vegetable charcoal pigments, anthocyanin pigments, carotenoid pigments, quinone pigments, flavonoid pigments, betaine pigments, monascus pigments, and other pigments derived from natural sources.

Examples of anthocyanin pigments include red radish pigment, red cabbage pigment, red rice pigment, elderberry pigment, cowberry pigment, gooseberry pigment, cranberry pigment, salmonberry pigment, perilla pigment, sim blueberry pigment, strawberry pigment, dark sweet cherry pigment, cherry pigment, hibiscus pigment, huckleberry pigment, grape juice pigment, grape skin pigment, blackcurrant pigment, blackberry pigment, blueberry pigment, plum pigment, white wortberry pigment, boysenberry pigment, mulberry pigment, purple sweet potato pigment, purple corn pigment, purple yam pigment, raspberry pigment, red currant pigment, loganberry pigment, and other anthocyanin pigments.

Examples of carotenoid pigments include annatto pigment, gardenia yellow, and other carotenoid pigments. Examples of quinone pigments include cochineal pigment, lithospermum pigment, lac pigment, and other quinone pigments. Examples of flavonoid pigments include safflower yellow, sorghum pigment, onion pigment, and other flavonoid pigments. Examples of betaine pigments include beet tod pigment. Examples of monascus pigments include monascus pigment and monascus yellow.

Other pigments derived from natural sources include turmeric pigment, gardenia red pigment, and spirulina blue pigment.

Additionally, the ink composition of the embodiment may contain additives such as flavorings, preservatives (bacteriostatic agents), antifoaming agents, and surfactants, as necessary. If the printing subject is a drug or edible object, edible additives may also be selected. Furthermore, when mixing the various components described above with the ink composition of the embodiment, pre-treatment or post-treatment such as heating may be performed.

(Example of printing on printed tablets)
Fig. 2 is a diagram showing an example of a printed tablet T having identification information printed on its surface using an ink composition according to an embodiment. The tablet in Fig. 2 is, for example, a medical plain tablet formed by compressing a powder containing a medicinal ingredient into the shape of a tablet.

As shown in FIG. 2, an identification code IC (ICc, ICp) is printed as identification information on the surface of the printed tablet T using the ink composition of the embodiment. The identification code IC is a character or a pictogram printed on a tablet or the like for the purpose of identifying the medicine, and includes a company code ICc and a product code ICp.

The company code ICc is used to distinguish the company and is a mark, abbreviation, symbol, alphabet, kana characters, kanji characters, mark, etc. that represents the company. The product code ICp is a number, symbol, etc. used for management within the company.

The identification information printed on the surface of the printed tablet T may include not only the identification code IC, which includes the company code ICc and product code ICp described above, but also other information, such as the name of the drug and the amount of ingredients.

Furthermore, the printed tablets using the ink composition of the embodiment may be not only the above-mentioned bare tablets, but also, for example, oral disintegration (OD) tablets, sugar-coated tablets, film-coated tablets, enteric-coated tablets, multi-layer tablets, dry-coated tablets, etc.

OD tablets are fragile tablets that are molded to dissolve in the mouth. Sugar-coated tablets are tablets in which the surface of a molded drug is covered with sugar. Film-coated tablets are tablets in which the surface of a molded drug is covered with a water-soluble ingredient. Enteric-coated tablets are tablets in which the surface of a molded drug is covered with a membrane that is less soluble in the stomach but dissolves in the intestines to prevent the drug ingredients from being altered by gastric acid or irritating the stomach. Multi-layer tablets are tablets in which the drug ingredients are covered with multiple layers, for example with different solubilities. Dry-coated tablets are tablets in which multiple drug ingredients that may be altered when mixed are separated into an inner core and an outer layer.

Printed tablets using the ink composition of the embodiment may also include capsules such as gelatin-encapsulated tablets, or tablets encapsulated using gelatin and glycerin or gelatin and sorbitol.

Furthermore, printed tablets using the ink composition of the embodiment can include not only the above-mentioned pharmaceutical tablets T, but also tablets used for eating, cleaning, industrial use, or fragrance.

An example of the above tablet is one that contains magnesium oxide as a main component. Below, a detailed description is given of tablets that contain magnesium oxide as a main component. Note that the "main component" in the embodiment refers to a component whose content in the tablet is 70% or more, and in particular, those that contain magnesium oxide as a main component are referred to as magnesium oxide tablets.

・Magnesium oxide:
The magnesium oxide contained in the magnesium oxide tablet of this embodiment may be in either powder or granular form, but the granular form allows for a tablet with a high content and excellent shape retention stability to be obtained. From the viewpoint of achieving the effects of this embodiment, it is preferable to adjust the average particle size of the magnesium oxide particles and the specific surface area of the granules within a predetermined range.

The magnesium oxide particles used in this embodiment may preferably have a predetermined average particle size, although it is not limited thereto. The average particle size in this embodiment refers to the volume-based 50% particle size (D50) measured by a laser diffraction scattering method. The upper limit of the average particle size of the magnesium oxide particles measured by a laser diffraction scattering method can be, for example, usually 40 μm or less, or 20 μm or less, or 10 μm or less. By setting the average particle size of the magnesium oxide particles to the above upper limit or less, the printing ink penetrates between the magnesium oxide particles constituting the tablet, making it difficult for light to reach the ink that has penetrated, and the effect of improving the light resistance of the ink and therefore the fading resistance may be obtained. On the other hand, the lower limit of the average particle size is not limited, but can be, for example, usually 0.25 μm or more, 0.5 μm or more, or 1 μm or more, depending on the manufacturing limitations and cost-effectiveness. As long as the average particle size of the magnesium oxide particles is within the above range, two or more types of magnesium oxide particles having different average particle sizes may be mixed in any combination and ratio and used.

The laser diffraction scattering method used to determine the average particle size of magnesium oxide particles in this embodiment is measured by the following method. 0.7 g of magnesium oxide and 70 mL of 0.2% sodium hexametaphosphate aqueous solution are added to a beaker, and a dispersion process is performed using an ultrasonic homogenizer (US-300, manufactured by Nippon Seiki Co., Ltd.). The average particle size of the magnesium oxide after dispersion can be measured using a laser diffraction scattering type particle size distribution measuring device (Microtrack, manufactured by Nikkiso Co., Ltd.).

The BET specific surface area of the magnesium oxide granules used in this embodiment is controlled by the crystal growth degree and impurity content of magnesium hydroxide before calcination, the steam atmosphere during calcination, etc. The magnesium oxide granules tend to have a higher BET if the crystal growth degree of magnesium hydroxide before calcination is higher. In addition, the magnesium oxide granules tend to have a lower BET if the magnesium hydroxide before calcination has a higher impurity content. Furthermore, the magnesium oxide granules tend to have a lower BET if magnesium oxide powder is calcined in an atmosphere with a higher amount of steam. It is preferable to appropriately adjust the above conditions so that the BET specific surface area of the magnesium oxide granules is within the following lower and upper limits. The lower limit is 5 m ² /g or more, preferably 10 m ² /g or more, and more preferably 15 m ² /g or more. The upper limit is 150 m ² /g or less, 100 m ² /g or less, more preferably 60 m ² /g or less, and even more preferably 50 m ² /g or less, and even more preferably 40 m ² /g or less. By adjusting the BET specific surface area within this range, the water absorption of magnesium oxide can be suppressed. In other words, by using magnesium oxide having the above-mentioned BET specific surface area and forming it into a tablet, a magnesium oxide tablet with high water resistance can be obtained. In particular, when the BET specific surface area is 50 m ² /g or less, water absorption is significantly suppressed, so that bleeding of the printed ink can be suppressed, and the effect of suppressing fading of the ink in the embodiment of the present application can be suitably achieved.

In this embodiment, the BET specific surface area means the specific surface area of magnesium oxide granules measured by the BET method. Specifically, the BET specific surface area can be measured using a fully automatic surface area measuring device (manufactured by Microtrackbell Co., Ltd.).

The magnesium oxide content in the tablet is not limited, but can be, for example, typically 70% by mass or more, or 80% by mass or more, and typically 95% by mass or less, or 90% by mass or less.

The content of additives other than magnesium oxide is not limited, but can be, for example, typically 5% by mass or more, or 10% by mass or more, and typically 30% by mass or less, or 20% by mass or less. Examples of the additives include binders, disintegrants, and lubricants. The content of additives other than magnesium oxide is relatively small compared to magnesium oxide, and has little effect on the ink composition of this embodiment.

Binder:
The tablet in this embodiment may contain a binder. The binder is not limited to, but may be, for example, crystalline cellulose, sodium carboxymethylcellulose, low-substituted hydroxypropylcellulose, starch, or sugar alcohol. Any one of these may be used alone, or two or more may be used in any combination and ratio. The timing of addition is not important. The content of the binder in the tablet is not limited to, but may be, for example, usually 1% by mass or more, or 3% by mass or more, and usually 15% by mass or less, or 13% by mass or less.

Disintegrant:
The tablet in this embodiment may contain a disintegrant. The disintegrant is not limited to, but may be, for example, starch, croscarmellose sodium, crospovidone low-substituted hydroxypropylcellulose, carmellose calcium, carmellose, sodium carboxystarch, or insoluble polyvinylpyrrolidone. Any one of these may be used alone, or two or more may be used in any combination and ratio. The content of the disintegrant in the tablet is not limited to, but may be, for example, usually 0.5% by mass or more, or 1% by mass or more, and usually 10% by mass or less, or 7% by mass or less.

·lubricant:
The tablet in this embodiment may contain a lubricant. The lubricant is not limited, but may be, for example, stearic acid and its salts (Na, Mg, Ca salts). Among them, calcium stearate is preferred. Any one of these may be used alone, or two or more may be used in any combination and ratio. The content of the lubricant in the tablet is not limited, but may be, for example, usually 0.2% by mass or more, or 0.5% by mass or more, or 0.7% by mass or more, and usually 3% by mass or less, or 2% by mass or less, or 1.5% by mass or less.

・Other ingredients:
The tablet in this embodiment may contain other additional components. These additional components may be used alone or in any combination and ratio of two or more. Examples include sweeteners, flavoring powders, flavoring agents, and flow agents. The content of other components in the tablet is not limited, but may be, for example, usually 0.05% by mass or more, or 0.1% by mass or more, or 0.2% by mass or more, and usually 2% by mass or less, or 1% by mass or less, or 0.5% by mass or less.

When the tablet contains magnesium oxide as an active ingredient, the manufacturing method for magnesium oxide tablets may include a granulation step and a tableting step of magnesium oxide granules. The manufacturing method may include a step of mixing magnesium oxide powder with an additive, a step of granulating the mixture to form magnesium oxide granules, a step of mixing the magnesium oxide granules with an additive, and a step of tableting.

When the formulation of this embodiment is made into a tablet, a raw material mixture for tableting is first prepared. The raw material mixture can be prepared by appropriately mixing, in addition to magnesium oxide particles, which is an active pharmaceutical ingredient, for example, some or all of the above-mentioned binder and disintegrant, and optionally other additional ingredients. The raw material mixture is then granulated into granular particles. Such granulation can be carried out, for example, using a dry granulator. An example of a dry granulator is a roll-molding type dry granulator. The granulated sheet-like molded product is then pulverized to obtain granular particles. For example, an oscillator-type pulverizer can be used for pulverization. The size of the granular particles is not limited, but can be, for example, an average particle size of 0.25 mm to 0.4 mm, an apparent density of 0.5 g/mL to 0.7 g/mL, and an angle of repose of 35° to 43°.

These granular particles can be mixed with a lubricant, optionally with the remainder of the binder and disintegrant, and optionally with other additional ingredients as required, and then compressed into tablets.

From the viewpoint of achieving the effect of this embodiment, it is preferable that the porosity of the magnesium oxide tablets used in this embodiment is adjusted within a predetermined range. The upper limit of the porosity can be, for example, usually 60% or less, or 50% or less, or 45% or less. On the other hand, the lower limit of the porosity can be, for example, usually 15% or more, or 20% or more, or 25% or more. By setting the porosity within the above range, it may be possible to obtain the effect that the ink penetrates into the pores, making it difficult for light to reach the ink that has penetrated, thereby improving the stability, light resistance, and therefore fading resistance of the ink.

The porosity of a tablet can be measured, for example, by mercury intrusion porosimetry using a pore size distribution measuring device (Autopore V9620, manufactured by Micrometrics).

(Example of configuration of tablet printing device)
When printing identification information or the like on a tablet using the ink composition of the embodiment, for example, an inkjet method can be used. Figure 3 shows an example of an inkjet type tablet printing device.

Figure 3 is a schematic diagram showing an example of the configuration of the tablet printing device 1 according to the embodiment. As shown in Figure 3, the tablet printing device 1 includes a tablet supply unit 10, a transport unit 20, a detection unit 30, an imaging unit 40, a printing unit 50, an imaging unit 60, a recovery unit 70, an ink supply unit 80, and a control device 90.

The tablet supply unit 10 has a hopper 11 and a chute 12. The tablet supply unit 10 is located at one end of the conveying unit 20 and is configured to be able to supply tablets T, which are the printing objects, to the conveying unit 20.

The hopper 11 is configured to store a large number of tablets T and to be able to sequentially supply the stored tablets T to the chute 12. The chute 12 is configured to be able to align the tablets T supplied from the hopper 11 in a single line and supply them to the conveying section 20.

The tablet supply unit 10 is electrically connected to the control device 90, and the operation of the tablet supply unit 10 is controlled by the control device 90.

The conveying section 20 has a conveying belt 21, a driving pulley 22, a number of driven pulleys 23, a motor 24, a position detector 25, and a suction chamber 26.

The conveyor belt 21 is an endless belt that is stretched across a drive pulley 22 and each driven pulley 23. The drive pulley 22 and each driven pulley 23 are rotatably mounted on the device body (not shown), and the drive pulley 22 is connected to a motor 24.

The motor 24 is electrically connected to the control device 90, and the drive of the motor 24 is controlled by the control device 90.

The position detector 25 is a device such as an encoder, and is attached to the motor 24. The position detector 25 is electrically connected to the control device 90 and transmits a detection signal to the control device 90.

The conveying unit 20 is configured to rotate the conveying belt 21 together with each driven pulley 23 by rotating the driving pulley 22 by the motor 24, and to convey the tablets T on the conveying belt 21 in the conveying direction H1, which is the rotation direction of the driving pulley 22, etc.

The conveyor belt 21 has a plurality of circular suction holes (not shown). Each of these suction holes is a through hole that adsorbs the tablet T, and is arranged in a row along the conveying direction H1 to form a single conveying path. Each suction hole is connected to the inside of the suction chamber 26 via a suction path (not shown) formed in the suction chamber 26, and is configured to be able to obtain suction force from the suction chamber 26.

A pump is connected to the suction chamber 26 via a suction pipe (neither shown), and the pressure inside the suction chamber 26 is reduced by operating the pump. The suction pipe is connected to approximately the center of the side of the suction chamber 26 that is parallel to the conveying direction H1. The pump is electrically connected to the control device 90, and the operation of the pump is controlled by the control device 90.

When the pressure inside the suction chamber 26 is reduced, the tablets T placed on each suction hole of the conveyor belt 21 are sucked through the suction holes and held on the conveyor belt 21.

The detection unit 30 is located downstream in the conveying direction H1 from the position where the tablet supply unit 10 is provided, and is provided above the conveyor belt 21. The detection unit 30 is configured to be able to detect the position of the tablet T on the conveyor belt 21 in the conveying direction H1 by projecting and receiving laser light.

As the detection unit 30, for example, a displacement sensor or a proximity sensor is used. As the displacement sensor, for example, various laser sensors such as a reflective laser sensor are used. The detection unit 30 is electrically connected to the control device 90 and transmits a detection signal to the control device 90.

The imaging unit 40 is located downstream in the conveying direction H1 from the position where the detection unit 30 is provided, and is provided above the conveyor belt 21. In addition, lighting for imaging is also provided as necessary.

The imaging unit 40 captures an image of the tablet T when it reaches an imaging position directly below the imaging unit 40 based on the position information of the tablet T in the conveying direction H1 detected by the detection unit 30, obtains an image including the top surface of the tablet T before printing, and transmits the obtained image to the control device 90.

The pre-printed image of the tablet T is used to detect the position of the tablet T in the conveying direction H1, the width direction of the conveying belt 21 perpendicular to the conveying direction H1, and the rotation direction.

As the imaging unit 40, various cameras having imaging elements such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CIS) image sensor are used. The imaging unit 40 is electrically connected to the control device 90, and the driving of the imaging unit 40 is controlled by the control device 90.

Here, the position of the tablet T in the conveying direction H1 and the direction perpendicular thereto is, for example, a position in a Cartesian coordinate system relative to the center of the imaging area of the imaging unit 40, which is the reference position during imaging. The position in the rotational direction is, for example, a position indicating the degree of rotation of the tablet T within the horizontal plane of the imaging area of the imaging unit 40. This position in the rotational direction is detected when the tablet T has a shape with directional properties, such as when the tablet T has a score line or is molded into an oval, elliptical, rectangular, or other shape.

The printing unit 50 has an inkjet head 51.

The inkjet head 51 is located downstream in the conveying direction H1 from the position where the imaging unit 40 is provided, and is provided above the conveying belt 21.

The inkjet head 51 has multiple nozzles (not shown), for example hundreds to thousands, and the direction of the nozzle row in which the nozzles are lined up is perpendicular to the transport direction H1 in a horizontal plane. The inkjet head 51 is configured to be able to eject ink individually from each nozzle by operating a drive element for each nozzle.

As the inkjet head 51, various inkjet print heads having driving elements such as piezoelectric elements, heating elements, or magnetostrictive elements are used. The inkjet head 51 is electrically connected to the control device 90, and the driving of the inkjet head 51 is controlled by the control device 90.

The imaging unit 60 is located downstream in the conveying direction H1 from the position where the printing unit 50 is provided, and is provided above the conveyor belt 21. If necessary, lighting for imaging is also provided.

The imaging unit 60 captures an image of the tablet T when it reaches an imaging position directly below the imaging unit 60 based on the position information of the tablet T in the conveying direction H1 detected by the detection unit 30, obtains an image including the top surface of the tablet T after printing, and transmits the obtained image to the control device 90.

The image of the printed tablet T is used to inspect the printed pattern on the surface of the printed tablet T.

As the imaging unit 60, various cameras having imaging elements such as a CCD or CMOS may be used, similar to the imaging unit 40 described above. The imaging unit 60 is electrically connected to the control device 90, and the driving of the imaging unit 60 is controlled by the control device 90.

The recovery unit 70 is located downstream in the transport direction H1 from the position where the imaging unit 60 is provided, and is provided at the downstream end of the transport unit 20 in the transport direction H1.

The conveying unit 20 releases the holding of the printing tablet T when the printing tablet T on the conveying belt 21 reaches a predetermined position, for example, the downstream end of the conveying unit 20 in the conveying direction H1. The recovery unit 70 is configured to be able to separate the printing tablet T that falls after being released from the holding by the conveying unit 20 into defective and non-defective tablets and recover them.

For example, by blowing gas onto the printed tablets T as they fall, changing the direction in which the printed tablets T fall between defective and non-defective, or by changing the path of fall using a member such as a plate, it is possible to separate the falling printed tablets T into defective and non-defective and collect them separately. Defective tablets are, for example, tablets that fail printing, and non-defective tablets are tablets that pass printing.

The recovery unit 70 is electrically connected to the control device 90, and the operation of the recovery unit 70 is controlled by the control device 90.

The ink supply unit 80 has an ink supply device 81. The ink supply device 81 is configured to be able to supply, for example, the ink composition of the embodiment to the inkjet head 51.

The ink supply device 81 has an ink bottle 81a, an ink pressure pipe 81b, an ink supply pipe 81c, an ink pressure valve 81e, an air release valve 81f, and a backflow prevention valve 81g.

The ink bottle 81a is a container such as an ink tank that stores an ink composition. The ink composition has an expiration date, and the expiration date is set to, for example, 24 hours after the ink bottle 81a is opened, i.e., after the ink composition in the ink bottle 81a comes into contact with air.

The ink pressurization pipe 81b supplies an inert gas such as nitrogen gas to the inside of the ink bottle 81a.

One end of the ink pressurization pipe 81b enters the ink bottle 81a from the top surface of the ink bottle 81a and extends to a position where it does not contact the liquid surface inside the ink bottle 81a. The other end of the ink pressurization pipe 81b branches into two.

An ink pressurization valve 81e is provided on one of the two branched pipes, and an air release valve 81f is provided on the other pipe. A backflow prevention valve 81g is provided between the end of the ink pressurization pipe 81b on the ink bottle 81a side and the branch point where the ink pressurization pipe 81b branches.

The ink pressure valve 81e, the air release valve 81f, and the check valve 81g are each electrically connected to the control device 90, and their opening and closing are controlled by the control device 90.

The ink supply pipe 81c connects the ink bottle 81a to the inkjet head 51, enabling the ink composition to be supplied from the ink bottle 81a to the inkjet head 51.

One end of the ink supply pipe 81c enters the ink bottle 81a from the top surface thereof and extends to near the bottom surface of the ink bottle 81a while being immersed in the ink composition stored therein. The other end of the ink supply pipe 81c is connected to the inkjet head 51.

The control device 90 controls each part of the tablet printing device 1, such as the tablet supply unit 10, the transport unit 20, the imaging unit 40, the printing unit 50, the imaging unit 60, the recovery unit 70, and the ink supply unit 80, based on various information and various programs. The control device 90 also receives detection information, such as detection signals, transmitted from the position detector 25 and the detection unit 30, and also receives image information, etc., transmitted from the imaging unit 40 and the imaging unit 60.

The control device 90 is realized, for example, by an electronic circuit such as an integrated circuit or a computer.

Note that the tablet printing device 1 shown in FIG. 3 is merely one example, and devices with various different configurations can be used to print tablets T using the inkjet method.

In the above-described tablet printing device 1, the tablets T are transported in a single row, but the number of rows of tablets T may be multiple. The number of conveyor belts 21 may also be multiple, and the number of inkjet heads 51 may also be multiple. In this case, multiple inkjet heads 51 may be arranged in a direction perpendicular to the conveying direction H1.

In addition, in the above-described tablet printing device 1, a print head with nozzles arranged in a single row is exemplified as the inkjet head 51, but it is also possible to use a print head with nozzles arranged in multiple rows, for example.

In addition, in the above-mentioned tablet printing device 1, the inkjet head 51 is illustrated as being arranged so that the direction in which the nozzles are arranged is perpendicular to the conveying direction H1, but the inkjet head 51 may also be arranged so that the direction in which the nozzles are arranged is perpendicular to the conveying direction H1.

In addition, in the above-mentioned tablet printing device 1, the tablets T are sucked and held by the suction holes formed on the conveyor belt 21, but the tablets T may be stored and held in a pocket or the like and conveyed, or may be held by their own weight on the conveyor belt 21 and conveyed.

In addition, in the above-mentioned tablet printing device 1, printing on one side of the tablet T has been exemplified, but both sides of the tablet T may be printed. In this case, for example, the conveying unit 20, the detection unit 30, the imaging unit 40, the printing unit 50, and the imaging unit 60 may be combined into one unit, and the unit may be arranged vertically stacked. As a result, after printing on one side of the tablet T in the upper unit, the tablet T with one side already printed can be inverted by the upper conveying unit 20 and handed over to the lower conveying unit 20, and the other side of the tablet T can be printed in the lower unit.

(Tablet printing method)
Next, the printing method for tablets T using the ink composition of the embodiment will be described with reference to Fig. 3. The ink composition of the embodiment is stored in an ink bottle 81a of an ink supply device 81 shown in Fig. 3. Also, a large number of tablets T before printing are stored in a hopper 11.

Referring to FIG. 3, the control device 90 drives the motor 24 of the conveying unit 20 to rotate the driving pulley 22 and the multiple driven pulleys 23, and starts the movement of the conveying belt 21. The control device 90 also drives a pump (not shown) in the suction chamber 26 to start suction from a suction hole (not shown) on the conveying belt 21.

The control device 90 continues suction through the suction holes until printing on the specified number of tablets T is completed, and also continues moving the conveyor belt 21 based on the detection signal from the position detector 25.

The control device 90 controls the tablet supply unit 10 to supply the tablets T contained in the hopper 11 to the chute 12, align the tablets T in a line, and supply them sequentially onto the conveyor belt 21 of the conveyor unit 20. The tablets T supplied onto the conveyor belt 21 are adsorbed to a predetermined position on the conveyor belt 21 by the suction holes and are conveyed in the conveying direction H1 as the conveyor belt 21 moves.

The detection unit 30 detects tablets T on the conveyor belt 21 that pass below the detection unit 30. The detection unit 30 transmits detection information indicating the position of the tablets T in the conveying direction H1 to the control device 90.

The control device 90 controls the imaging unit 40 based on the detection signal from the detection unit 30 to capture an image of the top surface of the tablet T before printing when the tablet T reaches an imaging position directly below the imaging unit 40. The imaging unit 40 transmits the captured image to the control device 90.

The control device 90 calculates the position of the tablet T in the conveying direction H1, the width direction of the conveying belt 21 perpendicular to the conveying direction H1, and the rotational direction based on the captured image from the imaging unit 40.

Based on the calculated position of the tablet T, the control device 90 ejects the ink composition from the inkjet head 51 onto the top surface of the tablet T when the tablet T reaches the printing position directly below the inkjet head 51.

The control device 90 controls the imaging unit 60 based on the detection signal from the detection unit 30 to capture an image of the top surface of the printed tablet T when the printed tablet T reaches the imaging position directly below the imaging unit 60. The imaging unit 60 transmits the captured image to the control device 90.

The control device 90 inspects the printed pattern on the surface of the printed tablet T based on the captured image from the imaging unit 60 and judges whether it is good or bad. In other words, among the printed tablets T, tablets that fail printing are judged to be defective, and tablets that pass printing are judged to be good.

When the printed tablet T reaches the downstream end of the conveying section 20 in the conveying direction H1, the control device 90 releases the holding of the printed tablet T. The control device 90 controls the collection section 70 according to the pass/fail judgment based on the captured image from the imaging section 60, and collects the printed tablet T that falls after being released from the conveying section 20, separating it into defective and non-defective tablets.

This completes the printing process for tablets T using the ink composition of the embodiment.

(Summary)
By printing identification information such as letters or symbols on the surface of tablets for internal or oral use, etc., it is possible to improve the identification of the tablets and prevent dispensing errors by dispensers and incorrect administration by users. For example, for medical tablets, identification information such as the drug name, product code, amount of ingredients, company name and company code is printed on them.

One example of a printing method for tablets is the inkjet method. Inkjet printing allows printing to be done on tablets without contact, so it is suitable for printing on tablets that are at high risk of disintegrating, such as OD tablets.

On the other hand, when coloring objects such as tablets and edible objects that are to be ingested by patients or general users by printing or other methods, it is necessary to use dyes that comply with the standards of the Pharmaceutical Additives Standards, the Japanese Pharmacopoeia, or the Official Specification of Food Additives, and the dyes that can be used are limited.

For this reason, in the above-mentioned inkjet printing, dye inks containing dyes that are synthetic edible colorings are sometimes used. Compared to inks containing pigments, dye inks tend to produce darker colors of printed characters, making it possible to improve the visibility of identification information.

However, inks that contain dyes as colorants have the disadvantage that they are less lightfast than inks that contain pigments, and are more likely to fade when exposed to light.

For example, an ink composition containing only Food Red No. 3 as a coloring matter has low lightfastness and is prone to fading due to light. An ink composition containing only Food Red No. 104 has higher lightfastness than Red No. 3 alone, but still has insufficient lightfastness.

In response to this, the inventors have, as a result of intensive research, found that mixing Food Red No. 104 with Food Red No. 3, which has inferior light resistance, improves light resistance compared to mixing Red No. 104 alone.

The ink composition of the embodiment contains a dye, water, and ethanol, and contains Food Red No. 104 and Food Red No. 3 as dyes. This allows the blended pigments to have higher light resistance than an ink composition containing Red No. 104 alone, and prevents fading due to light. Therefore, the identifiability of identification information printed on tablet T, for example, can be maintained.

According to the ink composition of the embodiment, the ratio of Food Red No. 3 to Food Red No. 104 is 0.05 or more and less than 9, preferably 0.1 or more and 5 or less, and more preferably 0.25 or more and 0.5 or less, by weight. This results in an ink composition in which the color difference ΔE calculated by the above formula (1) is less than the value shown by an ink composition containing Food Red No. 104 alone, preferably less than 25, and more preferably less than 20.

According to the ink composition of the embodiment, the blending ratio of the dye in the entire ink composition is 0.1% by weight or more and 10% by weight or less, and more preferably 0.5% by weight or more and 8% by weight or less.

By making the blending ratio of the dye in the ink composition at least 0.1% by weight or more, it is possible to improve the color development during printing and increase the distinguishability. In addition, by making the blending ratio of the dye in the ink composition at most 10% by weight or less, it is possible to keep the viscosity of the ink composition low. Therefore, when printing by the inkjet method, clogging of the nozzle of the ink composition, etc., can be suppressed, and printing defects can be suppressed.

According to the embodiment of the printed tablet T, identification information is printed on the surface using the ink composition of the embodiment. This can increase the light resistance of the printed portion of the printed tablet T and suppress fading due to light. Therefore, the identifiability of the identification information printed on the tablet T can be maintained.

The tablet printing device 1 of the embodiment includes an ink supply unit 80 capable of supplying the ink composition of the embodiment, and an inkjet head 51 that ejects the ink composition of the embodiment supplied by the ink supply unit 80 onto the tablets T. In this way, by applying the ink composition of the embodiment to the tablet printing device 1, for example, fading of identification information printed on the tablets T due to light can be suppressed, and identifiability can be maintained.

According to the tablet printing method of the embodiment, the ink composition of the embodiment is supplied to the inkjet head 51, and the ink composition of the embodiment is ejected from the inkjet head 51 onto the tablet T. In this manner, by printing on the tablet T using the ink composition of the embodiment, for example, fading of the identification information printed on the tablet T due to light can be suppressed, and the identifiability can be maintained.

Next, the ink compositions of the examples will be described. The inventors prepared ink compositions by mixing Food Red No. 104 and Food Red No. 3 in various mixing ratios, and conducted tests to compare the lightfastness of these ink compositions.

First, the ink compositions of Examples 1 to 9 and Comparative Examples 1 to 4 were prepared according to the compositions shown in Table 1 below. Table 1 shows the blending amount of each composition in weight percent. The preparation method of these ink compositions is as follows.

Ethanol, purified water, propylene glycol, glycerin, and glycerin fatty acid ester were mixed in the amounts shown in Table 1, and dissolved by stirring while heating to 50°C.

After each component was dissolved, Food Red No. 104 and Food Red No. 3 were added to the solution as dyes in various ratios shown in Table 1, and the solution was further stirred at 50°C for 1 hour. Food Red No. 104 and Food Red No. 3 to be added to the solution may be in the form of powder, or may be in the form of a solution in which the powder is dissolved in water or the like, or in the form of a paste in which the powder is dispersed in water or the like, as long as these dyes are evenly dissolved or mixed in the solution.

Then, the mixture was left to stand for 1 hour, cooled to room temperature, and filtered to obtain the ink compositions of Examples 1 to 9 and Comparative Examples 1 to 4. All of these ink compositions were pink in color.

As shown in Table 1, the ink compositions of Examples 1 to 9 contain dyes that are a mixture of Food Red No. 104 and Food Red No. 3 in ratios ranging from 1:0.05 to 1:5.

In the ink composition of Comparative Example 1, Food Red No. 104 is used alone as the dye, and in the ink composition of Comparative Example 4, Food Red No. 3 is used alone as the dye. The ink compositions of Comparative Examples 2 and 3 contain dyes in which Food Red No. 104 and Food Red No. 3 are mixed in ratios of 1:9 and 1:19, respectively.

The total amount of dye was constant in the ink compositions of Examples 1 to 9 and Comparative Examples 1 to 4. In addition, the amounts of the other raw materials, ethanol, purified water, propylene glycol, glycerin, and glycerin fatty acid ester, were all uniform in the ink compositions of Examples 1 to 9 and Comparative Examples 1 to 4.

Next, the ink compositions of Examples 1 to 9 and Comparative Examples 1 to 4 were supplied to an inkjet head to print solidly on the surface of a white plain tablet so that 0.45 mg of the ink composition was uniformly distributed per square centimeter. The following light resistance test was also carried out on the printed tablets obtained in this manner.

The unpackaged printed tablets were irradiated with 165,000 Lx of ultraviolet and visible light for 7.3 hours, i.e., a cumulative total of 1.2 million Lx of ultraviolet and visible light. In addition, the values in the L ^* a ^* b ^* color system of the printed parts of the tablets before and after irradiation were measured using a spectrophotometer (SE7700 manufactured by Nippon Denshoku Industries Co., Ltd.), and the color difference ΔE was calculated using the above formula (1).

Between the ink compositions of Comparative Example 1 and Comparative Example 4, the ink composition of Comparative Example 1 had a smaller color difference ΔE. This shows that Food Red No. 104 has higher light resistance than Food Red No. 3, and is more likely to prevent fading of printed tablets.

The ink compositions of Comparative Example 2 and Comparative Example 3 both had a larger color difference ΔE than the ink composition of Comparative Example 1. This shows that even when Food Red No. 104 is mixed with Food Red No. 3, if the ratio of Food Red No. 3 is too high, the effect of increasing light resistance and suppressing fading cannot be obtained.

On the other hand, the ink compositions of Examples 1 to 9 all had a smaller color difference ΔE than the ink composition of Comparative Example 1. This shows that mixing Food Red No. 3 with Food Red No. 104 in a specified ratio can improve light resistance and suppress fading. The ink compositions of Examples 1 to 9 can also be used effectively in printing on magnesium oxide tablets.

In addition, in this example, the ink composition of Example 5, in which the ratio of Food Red No. 104 to Food Red No. 3 was 1:0.3, achieved the smallest color difference ΔE among the ink compositions of Examples 1 to 9. This shows that when the ratio of Food Red No. 104 to Food Red No. 3 is around 1:0.3, there is a point at which the effect of increasing light resistance and suppressing fading is maximized.

The relationship between the amount of Food Red No. 3 blended and the color difference ΔE in the ink compositions of Examples 1 to 9 and Comparative Examples 1 to 4 is shown in the graph in Figure 4.

Figure 4 is a graph showing the relationship between the amount of Food Red No. 3 in the ink compositions of Examples 1 to 9 and Comparative Examples 1 to 4 and the color difference ΔE before and after the lightfastness test. The horizontal axis of the graph represents the amount of Food Red No. 3 in the total amount of the ink composition as a weight ratio, and the vertical axis of the graph represents the color difference ΔE.

In the graph of Figure 4, the color difference ΔE is at a minimum when the amount of Food Red No. 3 is around 1.5% by weight, that is, when the ratio of Food Red No. 104 to Food Red No. 3 is around 1:0.3.

As described above, it was found that when the ratio of Food Red No. 104 to Food Red No. 3 is in the range of 1:0.05 to 1:9 (the ratio of Food Red No. 3 includes 0.05 but does not include 9), the color difference ΔE value is lower than when Food Red No. 104 is used alone, when the ratio is in the range of 1:0.1 to 1:5 (the ratio of Food Red No. 3 includes 0.1 and 5), the color difference ΔE is less than 25, and when the ratio is in the range of 1:0.25 to 1:0.5 (the ratio of Food Red No. 3 includes 0.25 and 0.5), an ink composition with a color difference ΔE of less than 20 is obtained.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

REFERENCE SIGNS LIST 1 Tablet printing device 10 Tablet supply section 20 Conveying section 21 Conveying belt 30 Detection section 40 Imaging section 50 Printing section 51 Inkjet head 60 Imaging section 70 Recovery section 80 Ink supply section 81 Ink supply device 90 Control device IC Identification code ICc Company code ICp Product code T Tablet

Claims (7)

Dye and
Water,
Ethanol,
The dye may be
Includes Food Red No. 104 and Food Red No. 3,
The ratio of the Food Red No. 3 to the Food Red No. 104 is 0.05 or more and 5 or less in weight ratio;
Ink composition. The blending ratio of the dye in the entire composition is 0.1% by weight or more and 10% by weight or less.
The ink composition according to claim 1 . The total blend ratio of the Food Red No. 104 and the Food Red No. 3 in the dye is 100%.
The ink composition according to claim 1 or 2. A surface on which identification information is printed using the ink composition according to claim 1 .
Printing tablets. The main ingredient of the tablets is magnesium oxide.
The printed tablet according to claim 4 . An ink supply section capable of supplying the ink composition according to claim 1 ;
A conveying unit that conveys tablets;
A detection unit that detects tablets transported by the transport unit;
and an inkjet head that ejects the ink composition supplied by the ink supply unit onto the tablet detected by the detection unit.
Tablet printing equipment. Supplying the ink composition according to claim 1 to an ink-jet head,
The tablet is transported by the transport unit.
Detecting the tablet transported by the transport unit;
The ink composition is ejected from the inkjet head onto the detected tablet.
Tablet printing method.

Images