WO2021059568A1 - Ink, method for producing said ink, and temperature indicator using said ink - Google Patents

Abstract

The purpose of the present invention is to provide: a temperature-sensing aqueous ink having excellent stability; a method for producing the temperature-sensing aqueous ink; and a temperature indicator that uses the temperature-sensing aqueous ink. The ink according to the present invention is an ink in which temperature-sensing particles are dispersed in an aqueous dispersion medium and is characterized in that the temperature-sensing particles contain: a temperature-sensing material, which contains a leuco dye, a color developer and a decoloring agent; and a surfactant.

Description

Ink, method of manufacturing the ink, and temperature indicator using the ink

The present invention relates to a technique of a temperature indicator for checking a temperature change of a temperature-controlled object, particularly a temperature-sensing water-based ink for marking the temperature indicator, a method for producing the water-based ink, and a temperature using the water-based ink. It is about the indicator.

Fresh foods, frozen foods, and cryopreserved medicines (for example, vaccines, biopharmacy) are required to be kept within a predetermined temperature range without interruption in the distribution process of production, transportation, storage, and sales. Therefore, conventionally, a method has often been adopted in which a data logger capable of continuously recording time and temperature is mounted on a shipping container to constantly measure and record the temperature in the distribution process.

The method using a data logger has the advantage of being able to clarify when a temperature problem occurred if the product was damaged due to temperature. However, this method is suitable for centrally managing a large number of products, and there is a weakness in terms of cost for managing individual products individually.

On the other hand, as a method of controlling the temperature of each product individually, there is a method of using a temperature indicator instead of a data logger. The temperature indicator is a member capable of knowing the change in ambient temperature by discoloring the marker portion when the temperature exceeds or falls below a preset temperature. Although the temperature indicator is not as accurate as a data logger, it is suitable for managing individual products because it is attached to each product individually. A temperature detection material is used for the marker portion that changes color.

In addition, by making the temperature detection material ink-like (that is, using the temperature detection ink), various printing methods can be used as markings (for example, characters, symbols, one-dimensional barcodes, two-dimensional barcodes) on the temperature indicator. (For example, gravure printing, screen printing, dispenser, inkjet printing) can be used.

Patent Document 1 describes an electron-donating color-developing organic compound, an electron-accepting compound, and a homogeneous phase solution of a reaction medium that controls the color reaction between the electron-donating color-developing organic compound and the electron-accepting compound. A microcapsule pigment comprising a reversible thermochromic composition comprising, and at least a reversible thermochromic writing oil-based ink composition comprising an organic solvent are disclosed.

Patent Document 2 describes a temperature detection material containing a temperature indicating material containing a leuco dye, a color developer and a decoloring agent, and a matrix material, wherein the matrix material is a non-polar material and the melting point of the matrix material. Discloses a temperature detection material, which is higher than the melting point of the temperature indicating material and is characterized in that the temperature indicating material forms a phase-separated structure in which the temperature indicating material is dispersed in the matrix material. Further, Patent Document 2 discloses a temperature detection ink containing the temperature detection material and a solvent.

Japanese Unexamined Patent Publication No. 2005-320485 International Publication No. 2018/110200

As described above, by using the temperature detection ink, various printing methods can be used as markings on the temperature indicator. Here, from the viewpoint of the manufacturing cost of the temperature indicator, marking by inkjet printing is preferable. From the viewpoint of environmental protection, it is preferable to use water-based ink.

It is clear that the technique described in Patent Document 1 relates to an oil-based ink composition and is not a water-based ink. On the other hand, Patent Document 2 suggests the possibility of water-based ink. However, Patent Document 2 does not specifically disclose the dispersibility of the temperature detecting material in the water-based ink.

In other words, there is a demand for a temperature-detecting water-based ink (in other words, a temperature-detecting water-based ink with excellent stability) that makes it easy to secure and maintain the dispersibility of the temperature-detecting material in the ink.

Therefore, an object of the present invention is to provide a temperature-detecting water-based ink having excellent stability, a method for producing the temperature-sensing water-based ink, and a temperature indicator using the temperature-sensing water-based ink.

(I) One aspect of the present invention is an ink in which temperature detection particles are dispersed in an aqueous dispersion medium.
The temperature detection particles provide a temperature detection material containing a leuco dye, a color developer and a decoloring agent, and an ink characterized by containing a surfactant.

The present invention can make the following improvements and changes to the above ink (I).
(I) In the temperature detection particles, the surfactant coats the fine particles of the temperature detection material in which the leuco dye and the color developer are dispersed in the matrix of the decolorizing agent.
(Ii) In the temperature detection particles, the surfactant is also present inside the temperature detection particles.
(Iii) The median diameter of the temperature detection particles is 0.1 μm or more and 100 μm or less.
(Iv) The temperature-sensing water-based ink further contains additives.
(V) The additive is a water-soluble resin binder, a conductive agent and / or a leveling agent.
(Vi) The temperature-sensing water-based ink contains a plurality of types of the temperature-detecting particles having different color-developing start temperatures, and each of the plurality of types of temperature-detecting particles develops color when the temperature falls below a predetermined temperature. It is a temperature detection particle containing a detection type temperature detection material.
(Vii) The temperature-sensing water-based ink contains a plurality of types of the temperature-detecting particles having different color-developing start temperatures, and each of the plurality of types of temperature-detecting particles develops color when the temperature exceeds a predetermined temperature. It is a temperature detection particle containing a detection type temperature detection material.
(Viii) The temperature detection water-based ink contains a plurality of types of the temperature detection particles having different color development start temperatures, and the plurality of types of temperature detection particles are a low temperature side detection type that develops color when the temperature falls below a predetermined temperature. It includes both the temperature detection particles containing the temperature detection material of the above and the temperature detection particles including the temperature detection material of the high temperature side detection type that develops color when the temperature exceeds a predetermined temperature.

(II) Another aspect of the present invention is the above-mentioned method for producing an ink.
A temperature detection material preparation step of mixing, melting, and solidifying the leuco dye, the color developer, and the decolorizing agent to prepare the temperature detection material.
An emulsion preparation step of preparing an emulsion of the temperature detection material / surfactant by heating and stirring and mixing the temperature detection material and the solution of the surfactant, and
A suspension preparation step of preparing a suspension of temperature-detecting particles / aqueous dispersion medium by stirring and mixing the heated emulsion and the heated aqueous dispersion medium and then cooling to room temperature while stirring.
The present invention provides a method for producing an ink, which is characterized by having.

The present invention can make the following improvements and changes in the above ink manufacturing method (II).
(Ix) After the suspension preparation step, there is further an additive mixing step of mixing the additive with the suspension.
(X) The temperature detection material preparation step includes a pulverization process for granulating the temperature detection material from agglomerates.

(III) Yet another aspect of the present invention is a temperature indicator in which a marker with a predetermined ink is printed on a printing substrate.
It provides a temperature indicator, characterized in that the predetermined ink is the ink described above.

According to the present invention, it is possible to provide a temperature-detecting water-based ink having excellent stability, a method for producing the temperature-sensing water-based ink, and a temperature indicator using the temperature-sensing water-based ink.

It is a schematic diagram which shows the temperature detection material and the principle of the color change, (a) shows the decoloring state, and (b) shows the developing state. It is a schematic diagram which shows the state of the color change of the temperature detection material of a high temperature side detection type. It is a schematic diagram which shows the state of the color change of the temperature detection material of a low temperature side detection type. It is a schematic diagram which shows the structural example of the temperature detection water-based ink which concerns on this invention. It is sectional drawing which shows an example of a temperature detection particle. It is sectional drawing which shows another example of a temperature detection particle. It is a process drawing which shows an example of the manufacturing method of the temperature detection ink which concerns on this invention. It is a photograph which shows the state of the color change of the printed character in the temperature indicator using the temperature detection water-based ink of Example 1. FIG.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. The present invention is not limited to the embodiments taken up here, and can be appropriately combined with a known technique or improved based on the known technique without departing from the technical idea of the invention. .. The same reference numerals may be given to substances and processes having the same meaning (including cases where the difference is small).

[Temperature detection material and its color change]
First, the temperature detection material used in the present invention and its color change will be briefly described. 1A and 1B are schematic views showing a temperature detection material and the principle of its color change, in which FIG. 1A represents a decolorized state and FIG. 1B represents a developed state.

The temperature detection material 4 is a material whose color density is reversibly changed by a temperature change (increasing / decreasing temperature), and as shown in FIG. 1, is an electron-donating compound, leuco dye 1, and an electron-accepting compound. Includes a color developer 2 and a decolorizing agent 3 to control the temperature range of discoloration. In the decoloring agent 3, the state in which the leuco dye 1 and the decoloring agent 2 are separated and dispersed is the decolorizing state (see FIG. 1 (a)), and the decoloring agent 3 crystallizes and the leuco dye 1 The state in which the color developer 2 is combined with the color developer 2 is the color development state (see FIG. 1B).

Next, the relationship between the temperature and the color change of the temperature detection material 4 will be briefly described with reference to FIGS. FIG. 2 is a schematic diagram showing the state of color change of the high temperature side detection type temperature detection material, and FIG. 3 is a schematic view showing the state of color change of the low temperature side detection type temperature detection material. In FIGS. 2-3, the vertical axis represents color density, the horizontal axis is the temperature, T _a is developer starting temperature, T _d is the decolorization initiation temperature.

In the high temperature side detection type temperature detection material 4, it is preferable to use a material that is difficult to crystallize as the decolorizing agent 3. The high temperature side detection type temperature detection material 4 is decolorized when it is rapidly cooled from the temperature M, which is the molten state (the decolorization state in which the leuco dye 1 and the color developer 2 are separated), to the color development start temperature T _{a or less.} The agent 3 solidifies in an amorphous state, and the leuco dye 1 and the color developer 2 are frozen in a separated state (that is, in a decolorized state).

As shown in FIG. 2, when gradually heated from the frozen state, the decolorizer 3 in the color developing start temperature T _a started to crystallize, with the rearrangement of molecules for crystallization leuco Dye 1 and color developer 2 combine to develop color. The developed state is maintained while the decolorizing agent 3 is crystallizing. When the temperature rises further, _{the crystals of the decolorizing agent 3 begin to melt at the decoloring start temperature T d} , and the leuco dye 1 and the decolorizing agent 2 are separated and decolorized. That is, the change in color density shows hysteresis with respect to the change in temperature.

Utilizing such properties of the color change, by using a developed starting temperature T _a is hot-side detection type was prepared so as to manage the upper limit temperature of the temperature control object temperature detecting material 4, the presence or absence of color change From (presence or absence of color development), it is possible to detect whether or not the temperature of the temperature-controlled object has reached the control upper limit temperature.

On the other hand, in the low temperature side detection type temperature detection material 4, it is preferable to use a material that is difficult to solidify (a material that easily maintains the supercooled liquid phase) as the decolorizing agent 3. When the low temperature side detection type temperature detection material 4 is slowly cooled from the temperature M which is the molten state, the decolorizing agent 3 becomes a supercooling liquid phase and the decoloring state (leuco dye 1 and the developing agent 2 are separated). Maintain the state).

As shown in FIG. 3, As you further cooled from the supercooled liquid phase state, is decolorizer 3 in the color developing start temperature T _a started to crystallize, with the rearrangement of molecules for crystallization Leuco dye 1 and color developer 2 combine to develop color. After that, even if the temperature rises, the developed state is maintained while the decolorizing agent 3 is crystallizing. When the temperature rises further, _{the crystals of the decolorizing agent 3 begin to melt at the decoloring start temperature T d} , and the leuco dye 1 and the decolorizing agent 2 are separated and decolorized. That is, the change in color density shows hysteresis with respect to the change in temperature.

Utilizing such properties of the color change, by using a developed starting temperature T _a cold side detection type temperature sensing material 4 was prepared so as to manage the lower limit temperature of the temperature control object, presence or absence of color change From (presence or absence of color development), it is possible to detect whether or not the temperature of the temperature-controlled object has reached the control lower limit temperature.

[Temperature detection water-based ink]
Next, the temperature-sensing water-based ink according to the embodiment of the present invention will be described.

FIG. 4 is a schematic diagram showing a configuration example of the temperature detection water-based ink. As shown in FIG. 4, the temperature-detecting water-based ink 100 contains an aqueous dispersion medium 20 and temperature-detecting particles 10 and / or 11 dispersed in the aqueous dispersion medium, and the temperature-sensing particles 10 and 11 are leuco dyes. 1. It contains a temperature detection material 4 containing a developer 2 and a decolorizing agent 3, and a surfactant 5. The temperature-sensing water-based ink 100 may further contain various additives (for example, the water-soluble resin binder 30 and other additives 40) in order to satisfy various properties required depending on the application.

From the viewpoint of printability and print quality, the content of the temperature-detecting particles 10 and 11 in the temperature-detecting water-based ink 100 is preferably 5% by mass or more and 20% by mass or less. By setting the content of the temperature-detecting particles in the ink to 5% by mass or more, the color development of the printed matter is enhanced and the visibility of the printed matter is improved. By setting the content of the temperature-detecting particles in the ink to 20% by mass or less, aggregation of the temperature-detecting particles can be suppressed. In the case of inkjet printing, 5% by mass or more and 10% by mass or less is more preferable.

The content of the water-soluble resin binder 30 in the temperature-detecting water-based ink 100 is preferably 1% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 15% by mass or less. By setting the content of the water-soluble resin binder in the ink to 1% by mass or more, the abrasion resistance of the printed matter can be improved and the peeling of the printed matter can be suppressed. By setting the content of the water-soluble resin binder in the ink to 30% by mass or less, an increase in ink viscosity is suppressed and more stable printing is possible.

The temperature detection water-based ink 100 _{is not limited to one color development start temperature Ta} (color develops when the temperature exceeds a predetermined temperature, or develops when the temperature falls below a predetermined temperature), and a plurality of color development starts. it may include a plurality of types of temperature sensing particles 10 and 11 having a temperature T different color development initiation temperature to indicate _a T _a. In other words, in the temperature detection water-based ink 100 of the present invention, since each of the temperature detection particles 10 and 11 is coated with the surfactant 5 and is independent, even if a plurality of types of temperature detection particles are mixed, it is chemically chemical. the advantage of not mutual interference (showing the different color development initiation temperature T _a to each other) to.

For example, if two or more types of temperature detection particles containing the high temperature side detection type temperature detection material 4 that develops color when the temperature exceeds a predetermined temperature are included, two or more temperatures can be detected, and the temperature detection resolution on the high temperature side can be detected. Is improved. Similarly, if two or more types of temperature detection particles containing the low temperature side detection type temperature detection material 4 that develops color when the temperature falls below a predetermined temperature are included, the temperature detection resolution on the low temperature side is improved. In addition, if both the temperature detection particles containing the high temperature side detection type temperature detection material 4 and the temperature detection particles including the low temperature side detection type temperature detection material 4 are included, both the upper limit temperature and the lower limit temperature can be managed. can do.

The surfactant does not necessarily completely cover the surface of the temperature detection particles. In the present invention, "coating" means that most of the surface of the temperature-sensing particles (for example, 60% or more of the entire surface) is surrounded by the surfactant.

Further, it is most desirable that the temperature detection particles 10 and 11 are evenly dispersed in the aqueous dispersion medium 20, but the temperature detection particles 10 and 11 may be dispersed in a state of being agglomerated to some extent. In other words, the temperature-detecting water-based ink 100 of the present invention includes the fact that the temperature-detecting particles 10 and 11 are dispersed in the aqueous dispersion medium 20 in a state of being agglomerated to some extent.

(Temperature detection particles)
FIG. 5A is a schematic cross-sectional view showing an example of the temperature detection particles, and FIG. 5B is a schematic cross-sectional view showing another example of the temperature detection particles. Both FIGS. 5A and 5B show a decolorized state. As shown in FIG. 5A, in the temperature detection particles 10, the surfactant 5 coats the fine particles of the temperature detection material 4 in which the leuco dye 1 and the color developer 2 are dispersed in the matrix of the decolorizing agent 3. ing.

Further, as shown in FIG. 5B, in the temperature detection particles 11, the surfactant 5 is present not only around the fine particles of the temperature detection material 4 but also inside the temperature detection particles. In the production of the temperature detection water-based ink 100 described later, the temperature detection particles 11 involve the surfactant 5 in the process of forming fine particles of the temperature detection material 4, and / or a plurality of fine temperature detection particles 10 are aggregated /. It is thought that it can be obtained by coalescing.

By coating the fine particles of the temperature detection material 4 with the surfactant 5, when the temperature detection water-based ink 100 is prepared, the undesired influence of the water-soluble resin binder 30 and the additive 40 on the temperature detection material 4 ( For example, it becomes possible to suppress an unwanted chemical reaction).

From the viewpoint of compatibility with various printing methods / printing devices and the storage stability of ink, it is preferable to adjust the particle size / particle size distribution of the temperature detection particles 10 and 11. The particle size / particle size distribution of the temperature-detected particles 10 and 11 can be measured by, for example, a particle size distribution measuring device, and the medium diameter (median diameter, _{also referred to as D 50} ) is preferably 0.1 μm or more and 100 μm or less, preferably 0.1. More preferably, it is μm or more and 10 μm or less. In the case of inkjet printing, a medium diameter of 0.1 μm or more and 2 μm or less is more preferable in order to suppress nozzle clogging.

(Leuco dye)
The leuco dye 1 constituting the temperature detection material 4 is an electron donating compound, and known dyes for pressure-sensitive copying paper and heat-sensitive recording paper can be used. For example, triphenylmethanephthalide, fluorane, phenothiazine, indrillphthalide, leucooramine, spiropyrane, rhodamine lactam, triphenylmethane, triazene, spiroftalanthene, naphtholactam, Examples include azomethine-based leuco dyes.

More specific examples include 9- (N-ethyl-N-isopentylamino) spiro [benzo [a] xanthene-12,3'-phthalide], 2-methyl-6- (Np-tolyl-N-). Ethylamino) -fluorane 6- (diethylamino) -2-[(3-trifluoromethyl) anilino] xanthene-9-spiro-3'-phthalide, 3,3-bis (p-diethylaminophenyl) -6-dimethylamino Phtalide, 2'-anilino-6'-(dibutylamino) -3'-methylspiro [phthalide-3,9'-xanthene], 3- (4-diethylamino-2-methylphenyl) -3- (1-ethyl -2-Methylindole-3-yl) -4-azaphthalide, 1-ethyl-8- [N-ethyl-N- (4-methylphenyl) amino] -2,2,4-trimethyl-1,2-dihydro Spiro [11H-chromeno [2,3-g] quinoline-11,3'-phthalide], can be mentioned.

Two or more kinds of leuco dyes 1 may be used in combination.

(Color developer)
The color developer 2 constituting the temperature detection material 4 changes the chemical structure of the leuco dye 1 by combining with the electron-donating leuco dye 1 to develop a color, and is used for pressure-sensitive copying paper or heat-sensitive recording. A known color developer for paper can be used. Further, the color developer is not limited to the color developer for pressure-sensitive copying paper and thermal recording paper, and the color developer 2 may be a compound that is an electron acceptor and can change the color of leuco dye 1.

For example, metal salts of carboxylic acid derivatives, salicylic acid metal salts, salicylic acid metal salts, sulfonic acids, sulfonates, phosphoric acids, phosphoric acid metal salts, acidic phosphoric acid esters, acidic phosphoric acid ester metal salts, phosphites, sub Metal phosphate salts can be preferably used. Those having high compatibility with leuco dye 1 and the decoloring agent 3 described later are particularly preferable.

More specific examples include benzyl 4-hydroxybenzoate, 2,2'-biphenol, 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, and 2,2-bis (3-cyclohexyl-4). -Phenols such as hydroxyphenyl) propane, bisphenol A, bisphenol F, bis (4-hydroxyphenyl) sulfide, paraoxybenzoic acid ester, gallic acid ester, etc. and 1,1-bis (4-hydroxyphenyl) cyclohexane, 1, Examples thereof include 1-bis (4-hydroxy-3-methylphenyl) cyclohexane and α, α, α'-tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene.

Two or more kinds of developer 2 may be used in combination. By combining a plurality of types of developer 2, the color density of leuco dye 1 at the time of color development can be adjusted. The mixing ratio of the developer 2 to the leuco dye 1 can be appropriately selected according to the desired color density. For example, about 0.1 to 100 parts by weight of the color developer 2 may be mixed with 1 part by weight of the leuco dye.

(Decolorizing agent)
The decolorizing agent 3 constituting the temperature detection material 4 is a compound capable of dissociating the bond between the leuco dye 1 and the developing agent 2, and controls the developing temperature of the leuco dye 1 and the developing agent 2. It is also a compound that can be produced. Generally, in the temperature range in which the leuco dye 1 and the color developer 2 are combined to develop a color, the decolorizing agent 3 is in a crystallized solid phase state. On the other hand, in the liquid phase state in which the decolorizing agent 3 is melted, the decoloring state is exhibited by exerting the function of dissociating the bond between the leuco dye 1 and the decolorizing agent 2. Therefore, the state change temperature of the decolorizing agent 3 is important for controlling the developing color temperature.

The decolorizing agent 3 is a material that does not change the chemical structure of the leuco dye 1 (that is, does not develop a color), and can dissociate the bond between the leuco dye 1 and the color developer 2 (leuco dye 1 and the developing agent 2). The binding force between the color developer 2 and the decoloring agent 3 is greater than the binding force with the coloring agent 2). For example, hydroxy compounds, ester compounds, glycerol compounds, acetate compounds, peroxy compounds, carbonyl compounds, aromatic compounds, aliphatic compounds, halogen compounds, amino compounds, imino compounds, N-oxide compounds, hydroxyamine compounds, nitro compounds, azo Examples thereof include compounds, diazo compounds, azi compounds, ether compounds, fats and oil compounds, sugar compounds, peptide compounds, nucleic acid compounds, alkaloid compounds and steroid compounds.

Specific examples of the ester compound include isopropyl myristate, diethyl sebacate, dimethyl adipate, decyl decanoate, diethyl phenylmalonate, diisobutyl phthalate, triethyl citrate, benzyl butyl phthalate, methyl nicotinate, 2-phenylacetate. Phenylethyl, benzyl silicate, methyl acetoacetate, dimethyl succinate, dimethyl sebacate, monoolein, ethyl stearate, methyl palmitate, di-n-octyl phthalate, benzyl benzoate, diethylene glycol dibenzoate, propionate 2 -Phenylethyl, butyl stearate, methyl myristate, methyl anthranilate, isopropyl palmitate, ethyl 4-fluorobenzoate, ethyl 2-bromopropionate, tristea, ethyl 1,3-dibromobutyrate, dimethyl adipate, 2 -Ethyl palmitate, diethyl terephthalate, phenyl stearate, methyl arachidate, methyl 4-chlorobenzoate, dimethyl dodecanoate, diethyl formaminomalonate, methyl pentadecanoate, ethyl arachidate, ethyl benzylate, dicyclohexylphthalate , 4-Aminobenzoate isobutyl, 4-hydroxybenzoate butyl, monoethyl fumarate, methyl benzylate, diphenyl phthalate, phenylbenzoate, 3-nitromethyl benzoate, methyl 3-hydroxy-2-naphthoate, oxalic acid Trimethyl, ethyl 4-aminobenzoate, methyl 4-nitrobenzoate, 2-naphthyl benzoate, dimethyl fumarate, adiphenine hydrochloride, ethyl 4-hydroxybenzoate, vinyl butyrate, methyl 4-iodobenzoate, propyl castorate , 1,4-diacetoxybenzene, diethyl allylmalonate, diethyl bromomalonate, diethyl ethoxymethylenemalonate, diethyl ethylmalonate, diethyl fumarate, diethyl maleate, diethyl malonate, diethyl phthalate, ethyl benzoate, 4- (Dimethylamino) Ethyl benzoate, ethyl nicotinate, benzyl laurate, benzyl acetate, methyl phenylacetate, phenylacetate, diethyl malonate, tributyrin, diethyl malonate, dimethyl malonate, dibenzyl malonate, dimethyl maleate, terephthal Methyl aldehyde, diallyl phthalate, benzyl bromoacetate, methyl phenylpropiolate, isobutyl benzoate, dibutyl sebacate, diethyl adipine, te Diethyl lephthalate, dipropyl phthalate, diisopropyl sorbitan tristearate adipate, sorbitan monostearate, stearic acid amide, glycerol monostearate, glycerol distearate, stearyl acrylate, dibenzyl phthalate, dimethyl nitroterephthalate, coumarin-3 Includes ethyl carboxylate, benzyl p-benzyloxybenzoate, methyl 4-chloro-3-nitrobenzoate, dimethyl terephthalate, methyl 4-amino-2-methoxybenzoate, and dimethyl 5-aminoisophthalate.

Specific examples of the glycerol compound include tripalmitin, tripalmitin, ethylene glycol dibenzoate, and triolein. Specific examples of acetate compounds include 4-diacetoxybutane, 1,1-ethanediol diacetate, benzaldiacetate, 1,4-diacetoxybutane, diethylene glycol diacetate, vitamin K4, 2,5-di. Acetoxytoluene, 1,1-ethanediol diacetate, and the like. Specific examples of the aromatic compound include m-tolyl acetate, 1,2-diacetoxybenzene, and valetamate bromide. Specific examples of the amino compound include ethyl anthranilate and butyl 4-aminobenzoate. Specific examples of the imino compound include methyl N-methylanthranilate. Specific examples of the nitro compound include ethyl 4-nitrobenzoate.

Specific examples of steroid compounds include cholesterol, cholesteryl bromide, β-estradiol, methyl androstendiol, pregnenolone, cholesterol benzoate, cholesterol acetate, cholesterol linoleate, cholesterol palmitate, cholesterol stearate, cholesterol oleate, 3-chloro. Cholesterol, hydrosilicate cholesterol, cholesterol laurate, cholesterol butyrate, cholesterol formate, cholesterol heptanate, cholesterol hexanoate, cholesterol myristate, cholesterol propionate, cholesterol phenylacetate, cholesterol chlorostate, 2,4-dichloro Cholesterol benzoate, cocholesterol oleyl carbonate, cholesterol amylcarbonate, cholesterol n-octylcarbonate, estron, ethynyl estradiol, estradiol, estradiol benzoate, α-estradiol, 17-heptanoate β-estradiol, 2-methoxy- β-estradiol, androsterone, avirateron, dehydroepiandrosterone, dehydroepiandrosterone acetate, etisterone, 17β-hydroxy-17-methylandrosta-1,4-diene-3-one, methylandrostendiol, 16- Dehydropregnenolone acetate, 11α-hydroxyprogesterone, 17α-hydroxyprogesterone caproate, 17α-hydroxyprogesterone acetate, megestol acetate cortisone, cortisone, cortexolone, deoxycorticosterone acetate, hydrocortisone, 6α-methylprednisolone, Prednisolone, prednison, β-cholestanol, cholesterol-5α, 6α-epoxide, diosgenin, ergosterol, β-citosterol, stigmasterol, β-citosterol acetate.

You may use two or more kinds of decolorizing agents 3 in combination. By combining a plurality of types of decolorizing agents 3, the discoloration temperature and the time required for discoloration can be adjusted.

(Surfactant)
The surfactant 5 constituting the temperature detection particles 10 and 11 is for dispersing the temperature detection material 4 in the aqueous dispersion medium 20, and various ionic surfactants (anionic, cationic, etc.) Amphoteric) and various nonionic surfactants can be utilized.

Examples of anionic surfactants include those in which the hydrophilic group is composed of a carboxylate, a sulfonate, a sulfate ester type, and a phosphoric acid ester type. Examples of cationic surfactants include those in which the hydrophilic group is composed of an amine salt, a pyridinium salt, and a benzyl halide salt. Examples of amphoteric tenside agents include those in which the hydrophilic group is composed of a carboxylate, a sulfonate, a sulfate ester type, and a phosphoric acid ester type.

Examples of nonionic surfactants include those in which the hydrophilic group is composed of ester, ethylene oxide, ether, amineamide, and sorbitol.

(Aqueous dispersion medium)
The temperature-sensing water-based ink 100 of the present invention preferably has a pH (potential of hydrogen) of 6 or more and 8 or less as a liquid property in order to suppress the influence on the color-developing / decoloring characteristics of the temperature-detecting material. .. The water-based dispersion medium 20 is not particularly limited as long as the temperature-sensing water-based ink 100 is adjusted to an appropriate liquid property, and may be pure water or an aqueous solution (for example, a buffer solution) for suppressing pH fluctuation. There may be.

(Additive)
(1) Water-soluble resin binder The temperature-detecting water-based ink 100 preferably contains the water-soluble resin binder 30 in order to help adjust the viscosity and adhere the temperature-detecting particles 10 and 11 to the temperature indicator base material. As the water-soluble resin binder 30, for example, acrylic resin, urethane resin, phenol resin, polyester, polyethylene oxide, styrene / maleic acid, polyvinyl alcohol, and polyacrylamide can be preferably used. The content of the water-soluble resin binder 30 in the temperature-detecting water-based ink 100 is preferably 1% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 15% by mass or less.

(2) Conductive agent When applying temperature-sensing water-based ink to a charge-controlled inkjet printer, it is desirable to adjust the electrical resistivity of the ink to 2000 Ωcm or less from the viewpoint of print controllability. The temperature-sensing water-based ink 100 of the present invention may contain a conductive agent as another additive 40 in order to adjust the electrical resistivity.

Since the conductive agent used here needs to be dissolved in the aqueous dispersion medium 20, water-soluble salts are preferable, and for example, nitrates, perchlorates, tetraphenylborates, and ammonium ion salts are preferably used. it can. More specific examples include lithium nitrate, sodium nitrate, ammonium nitrate, lithium perchlorate, sodium perchlorate, ammonium perchlorate, lithium tetraphenylborate, sodium tetraphenylborate, ammonium tetraphenylborate. Can be mentioned.

(3) Leveling Agent The temperature-sensing water-based ink 100 of the present invention may contain a leveling agent as another additive 40 in order to adjust the print quality.

(Manufacturing method of temperature detection water-based ink)
Next, a method for producing the temperature-sensing water-based ink 100 according to the present invention will be described.

FIG. 6 is a process diagram showing an example of a method for manufacturing a temperature detection ink according to the present invention. As shown in FIG. 6, first, the leuco dye, the developer, and the decolorizer are mixed, melted, and solidified so as to have _{the desired color development start temperature T a} and decolorization start temperature T _{d, and the temperature is detected.} Perform the temperature detection material preparation step (S1) for preparing the material 4. The melting is preferably carried out in a temperature range of 150 to 250 ° C.

The adjusted temperature detection material 4 can be used in the next process as it is in the form of a lump, but the lump may be crushed into granules. Although the pulverization process is not an essential process, it is preferable from the viewpoint of allowing the next process to proceed smoothly. The temperature sensing material preparation step S1 shall include a milling process.

Next, an emulsion preparation step (S2) is performed in which the temperature detection material 4 and the solution of the surfactant 5 are heated, stirred and mixed to prepare the temperature detection material / surfactant emulsion 6. The mass ratio of "temperature detection material: surfactant" is preferably "1: 1" to "1: 5", and the heating / stirring mixture is in the temperature range in which the temperature detection material 4 becomes droplets (for example, 80 to 100). ℃) is preferable. In addition, the size of the droplets of the temperature detection material 4 can be adjusted by the stirring speed. In other words, the stirring speed is controlled in order to control the size of the droplet of the temperature detection material 4 (the size of the later temperature detection particles 10 and 11).

Next, the emulsion 6 heated to a temperature range in which the temperature detection material 4 becomes droplets and the aqueous dispersion medium 20 heated to the temperature range are stirred and mixed, and then cooled to room temperature while stirring to obtain the temperature detection particles. / Perform the suspension preparation step (S3) to prepare the suspension 7 of the aqueous dispersion medium. As described above, the pH of the aqueous dispersion medium 20 is preferably adjusted to 6 to 8, and may be pure water or a buffer solution. The mixing amount of the aqueous dispersion medium 20 is preferably such that the mass ratio of "emulsion liquid: aqueous dispersion medium" is "1: 5" to "1:10". As a method of mixing the emulsion 6 and the aqueous dispersion medium 20, the aqueous dispersion medium 20 may be injected into the emulsion 6, or the emulsion 6 may be injected into the aqueous dispersion medium 20.

When the emulsion 6 and the aqueous dispersion medium 20 are mixed in the suspension preparation step S3, the temperature detection material 4 is hydrophobic, so that the surfactant 5 coats around the droplets of the temperature detection material 4. It becomes an emulsion in a state of being dispersed in the aqueous dispersion medium 20. When this emulsion is cooled, the droplets of the temperature detection material 4 are solidified, and a suspension 7 in which the temperature detection particles 10 and 11 are dispersed in the aqueous dispersion medium 20 is obtained.

Next, an additive mixing step (S4) is performed in which various additives (water-soluble resin binder 30, conductive agent and / or leveling agent) are mixed with the suspension 7. Although the additive mixing step S4 is not an essential step, it is preferable to perform the additive mixing step S4 from the viewpoint of adjusting print controllability and print quality as ink. As a result, the temperature detection water-based ink 100 is completed.

Although not shown in FIG. 6, when producing a temperature detection water-based ink containing a plurality of types of temperature detection particles having different color development start temperatures, a separately prepared suspension 7 or temperature detection is used. The water-based ink 100 may be appropriately mixed.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to these examples.

[Experiment 1]
(Preparation of Example 1)
As a leuco dye 2'-anilino-6'-(N-ethyl-N-isopentylamino) -3'-methylspiro [phthalide-3,9'-[9H] xanthene] (manufactured by Yamada Chemical Co., Ltd., S- 205) was used. Octyl gallate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as a color developer. As the decolorizing agent, a mixture of methyl p-toluate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2-phenylethyl phenylacetic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) at a mass ratio of "9: 1" was used. ..

Leuco dye: developer: decolorant was mixed at a mass ratio of "3: 3: 100", melted and stirred at 190 ° C, and then solidified to prepare a massive temperature detection material. The obtained mass was manually crushed in a mortar to prepare a granular temperature detection material (temperature detection material preparation step S1). This temperature detection material is in a decolorized (colorless) state in an environment maintained at room temperature (25 ° C.), but once cooled to 4 ° C. or lower, it develops a black color.

Weigh 0.5 g of the prepared temperature detection material and 2 g of the surfactant (Demol (registered trademark) EP manufactured by Kao Co., Ltd.), and mix by heating and stirring using a magnetic stirrer (95 ° C, 600 rpm, 10). Minutes) A temperature detection material / surfactant emulsion was prepared (emulsion solution preparation step S2).

Next, the emulsion at 95 ° C and the phosphate buffered aqueous solution heated to 95 ° C (concentration 0.1 mol / L, pH = 7.0, 20 g) were stirred and mixed (95 ° C, 600 rpm, 10 minutes). Then, the mixture was cooled to room temperature with stirring to prepare a suspension of temperature-detecting particles / aqueous dispersion medium (suspension preparation step S3).

In the suspension preparation step S3, when the emulsion and the phosphate buffered aqueous solution (aqueous dispersion medium) are stirred and mixed, the temperature detection material becomes spherical droplets in order to minimize the interfacial energy because it is hydrophobic. The emulsion becomes an emulsion in a state in which the droplets are coated with a surfactant and dispersed in a phosphate buffered aqueous solution. When the emulsion is cooled, the droplets of the temperature detection material are solidified to form a suspension in which spherical temperature detection particles are dispersed in a phosphate buffered aqueous solution.

When the particle size distribution of the temperature-detected particles of the obtained suspension was measured using a particle size distribution measuring device (Beckman Coulter Co., Ltd., model LS-230), it was confirmed that the medium diameter was about 1 μm. did.

Next, a water-soluble resin binder was mixed with the obtained suspension to prepare a temperature-sensing water-based ink of Example 1 (additive mixing step S4). Polyvinyl alcohol (PVA) was used as the water-soluble resin binder, and the mixture was mixed so that the content of the water-soluble resin binder in the temperature-detecting water-based ink was 5% by mass.

(Evaluation of Example 1)
A temperature indicator was produced using the temperature-detecting water-based ink of Example 1, and a confirmation experiment of printability and temperature detection was performed. A commercially available DOD (Drop On Demand) inkjet printer was used as the printing apparatus, and a commercially available art paper was used as the printing base material. A temperature change test (holding at 25 ° C for 10 minutes and then cooling to 4 ° C) was performed on the prepared temperature indicator, and the color change of the printed characters was visually confirmed. It was evaluated as "pass" when it was colorless when it was held at 25 ° C, and when it was cooled to 4 ° C and the printed characters could be identified, it was evaluated as "fail".

FIG. 7 is a photograph showing a state of color change of printed characters in a temperature indicator using the temperature detection water-based ink of Example 1. As shown in FIG. 7, the printed characters cannot be identified because they are colorless when kept at 25 ° C, but the printed characters can be identified by developing colors when cooled at 4 ° C. That is, Example 1 is evaluated as "passed". The components and evaluation results of the temperature-sensing water-based ink of Example 1 are summarized in Table 1 described later.

[Experiment 2]
(Preparation and evaluation of Comparative Example 1)
A granular temperature detection material was prepared in the same manner as in Example 1. Then, the granular temperature detection material was crushed using a jet mill to prepare a powder temperature detection material. When the particle size distribution of the obtained powdery temperature detection material was measured using a particle size distribution measuring device, it was confirmed that the median diameter was about 2 μm.

Next, 0.5 g of powdered temperature detection material was added to a phosphate buffered aqueous solution (concentration 0.1 mol / L, pH = 7.0, 22 g) heated to 95 ° C, and the mixture was stirred and mixed (95 ° C, 600 rpm, 20). After forming an emulsion (minutes), the mixture was cooled to room temperature with stirring to prepare a suspension of temperature-detecting particles / aqueous dispersion medium.

Next, a water-soluble resin binder was mixed with the obtained suspension to prepare a temperature-sensing water-based ink of Comparative Example 1. Polyvinyl alcohol was used as the water-soluble resin binder, and the mixture was mixed so that the content of the water-soluble resin binder in the temperature-detecting water-based ink was 5% by mass.

Next, a temperature indicator was produced in the same manner as in Example 1 using the temperature detection water-based ink of Comparative Example 1. The same temperature change test as in Example 1 (holding at 25 ° C. for 10 minutes and then cooling to 4 ° C.) was performed on the prepared temperature indicator. As a result, both the temperature was maintained at 25 ° C and the temperature was cooled at 4 ° C, and the printed characters were colorless, and no clear decolorization or color change due to temperature changes was observed. That is, Comparative Example 1 was evaluated as "failed". The components and evaluation results of the temperature-sensing water-based ink of Comparative Example 1 are also shown in Table 1.

In order to check the soundness of the temperature detection particles themselves, the temperature detection water-based ink of Comparative Example 1 was applied with a brush on the printing substrate, and then the same temperature change test as in Example 1 (after holding at 25 ° C. for 10 minutes, after holding for 10 minutes, Cooled to 4 ° C). As a result, it was colorless at both 25 ° C retention and 4 ° C cooling, but it was confirmed that the temperature detection particles were coated on the printing substrate.

Considering the factors that did not develop color in response to temperature changes, it is possible that the temperature detection particles themselves deteriorated due to the physical crushing process using the jet mill.

[Experiment 3]
(Preparation and evaluation of Example 2)
In the additive mixing step S4, the temperature-detecting water-based ink of Example 2 was obtained in the same manner as in Example 1 except that lithium nitrate was mixed so that the content of the conductive agent in the temperature-detecting water-based ink was 5% by mass. Was produced.

Next, a temperature indicator was produced using the temperature detection water-based ink of Example 2. A commercially available charge control type inkjet printer was used as the printing apparatus, and a commercially available art paper was used as the printing base material. The same temperature change test as in Example 1 (holding at 25 ° C. for 10 minutes and then cooling to 4 ° C.) was performed on the prepared temperature indicator. As a result, Example 2 was evaluated as "passed". The components and evaluation results of the temperature-sensing water-based ink of Example 2 are also shown in Table 1.

[Experiment 4]
(Preparation and evaluation of Examples 3 and 4)
In the emulsion preparation step S2, the temperature-sensing water-based ink of Example 3 was prepared in the same manner as in Example 1 except that Demol (registered trademark) NL manufactured by Kao Co., Ltd. was used as the surfactant, and the surface activity was prepared. The temperature-sensing water-based ink of Example 4 was prepared in the same manner as in Example 2 except that Demol (registered trademark) NL manufactured by Kao Co., Ltd. was used as the agent.

A temperature indicator was produced in the same manner as in Example 1 using the temperature-sensing water-based ink of Example 3, and a temperature indicator was produced in the same manner as in Example 2 using the temperature-sensing water-based ink of Example 4.

The prepared temperature indicator was subjected to the same temperature change test as in Example 1 (holding at 25 ° C for 10 minutes and then cooling to 4 ° C), and the color change of the printed characters was visually confirmed. As a result, both Examples 3 and 4 were evaluated as "passed". The components and evaluation results of the temperature-detecting water-based inks of Examples 3 and 4 are also shown in Table 1.

[Experiment 5]
(Preparation and evaluation of Examples 5 and 6)
3,3-Bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (manufactured by Yamada Chemical Co., Ltd., crystal violet lactone: CVL) is used as the leuco dye, and octyl gallate is used as the color developer. Vitamin K4 (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used as a coloring agent.

As the temperature detection material preparation step S1, leuco dye: color developer: decolorizer are mixed at a mass ratio of "2: 2: 100", melted and stirred at 180 ° C, and then solidified to prepare a massive temperature detection material. did. The obtained mass was manually crushed in a mortar to prepare a granular temperature detection material. This temperature detection material is colorless in an environment maintained at 25 ° C, but once heated to 40 ° C or higher, it develops a blue color.

Next, as the emulsion preparation step S2, 0.5 g of the temperature detection material and 2.5 g of the surfactant (Demol (registered trademark) EP manufactured by Kao Co., Ltd.) are weighed and mixed by heating and stirring using a magnetic stirrer. (95 ° C, 600 rpm, 10 minutes) An emulsion of temperature detection material / surfactant was prepared.

Next, as suspension preparation step S3, an emulsion at 95 ° C. and a phosphate buffered aqueous solution heated to 95 ° C. (concentration 0.1 mol / L, pH = 7.0, 20 g) were stirred and mixed (95 ° C., 600 rpm, 10 minutes). Then, the mixture was cooled to room temperature with stirring to prepare a suspension of temperature-detecting particles / aqueous dispersion medium. When the particle size distribution of the temperature-detected particles of the obtained suspension was measured using a particle size distribution measuring device, it was confirmed that the medium diameter was about 1.5 μm.

Next, in the additive mixing step S4, the temperature-detecting water-based ink of Example 5 was produced in the same manner as in Example 1, and the temperature-detecting water-based ink of Example 6 was produced in the same manner as in Example 2.

A temperature indicator was produced in the same manner as in Example 1 using the temperature-sensing water-based ink of Example 5, and a temperature indicator was produced in the same manner as in Example 2 using the temperature-sensing water-based ink of Example 6.

A temperature change test (holding at 25 ° C for 10 minutes and then heating to 40 ° C) was performed on the prepared temperature indicator, and the color change of the printed characters was visually confirmed. It was evaluated as "pass" when it was colorless when it was held at 25 ° C and developed when it was heated to 40 ° C and the printed characters could be identified, and it was evaluated as "fail" in other cases. As a result, both Examples 5 and 6 were evaluated as "passed". The components and evaluation results of the temperature-detecting water-based inks of Examples 5 and 6 are also shown in Table 1.

[Experiment 6]
(Preparation and evaluation of Examples 7 and 8)
In the emulsion preparation step S2, the temperature-sensing water-based ink of Example 7 was prepared in the same manner as in Example 5 except that Demol (registered trademark) NL manufactured by Kao Corporation was used as the surfactant, and the surface activity was increased. The temperature-sensing water-based ink of Example 8 was prepared in the same manner as in Example 2 except that Demol NL manufactured by Kao Corporation was used as the agent.

A temperature indicator was produced in the same manner as in Example 1 using the temperature-sensing water-based ink of Example 7, and a temperature indicator was produced in the same manner as in Example 2 using the temperature-sensing water-based ink of Example 8.

The prepared temperature indicator was subjected to the same temperature change test as in Example 5 (holding at 25 ° C for 10 minutes and then heated to 40 ° C), and the color change of the printed characters was visually confirmed. As a result, both Examples 7 and 8 were evaluated as "passed". The components and evaluation results of the temperature-detecting water-based inks of Examples 7 and 8 are also shown in Table 1.

[Experiment 7]
(Preparation and evaluation of Examples 9 and 10)
Example 5 and Example 5 except that vitamin K4 (manufactured by Tokyo Chemical Industry Co., Ltd.) and propyl gallate (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed as a decolorizing agent at a mass ratio of "1: 1". Similarly, a granular temperature detection material was prepared. This temperature detection material is colorless in an environment maintained at 25 ° C, but once heated to 50 ° C or higher, it develops a blue color.

Next, in the emulsion preparation step S2 and the suspension preparation step S3, a suspension of temperature-detecting particles / aqueous dispersion medium was prepared in the same manner as in Example 5. When the particle size distribution of the temperature-detected particles of the obtained suspension was measured using a particle size distribution measuring device, it was confirmed that the medium diameter was about 1.5 μm.

Next, in the additive mixing step S4, the temperature-detecting water-based ink of Example 9 was produced in the same manner as in Example 1, and the temperature-detecting water-based ink of Example 10 was produced in the same manner as in Example 2.

A temperature indicator was produced in the same manner as in Example 1 using the temperature-sensing water-based ink of Example 9, and a temperature indicator was produced in the same manner as in Example 2 using the temperature-sensing water-based ink of Example 10.

A temperature change test (holding at 25 ° C for 10 minutes and then heating to 50 ° C) was performed on the prepared temperature indicator, and the color change of the printed characters was visually confirmed. It was evaluated as "pass" when it was colorless when it was held at 25 ° C and developed when it was heated to 50 ° C and the printed characters could be identified, and it was evaluated as "fail" in other cases. As a result, both Examples 9 and 10 were evaluated as "passed". The components and evaluation results of the temperature-detecting water-based inks of Examples 9 and 10 are also shown in Table 1.

[Experiment 8]
(Preparation and evaluation of Examples 11 and 12)
In the emulsion preparation step S2, the temperature-sensing water-based ink of Example 11 was prepared in the same manner as in Example 5 except that Demol (registered trademark) NL manufactured by Kao Corporation was used as the surfactant, and the surface activity was increased. The temperature-sensing water-based ink of Example 12 was prepared in the same manner as in Example 2 except that Demol NL manufactured by Kao Corporation was used as the agent.

A temperature indicator was produced in the same manner as in Example 1 using the temperature-sensing water-based ink of Example 11, and a temperature indicator was produced in the same manner as in Example 2 using the temperature-sensing water-based ink of Example 12.

The prepared temperature indicator was subjected to the same temperature change test as in Example 9 (holding at 25 ° C for 10 minutes and then heated to 50 ° C), and the color change of the printed characters was visually confirmed. As a result, both Examples 11 and 12 were evaluated as "passed". The components and evaluation results of the temperature-detecting water-based inks of Examples 11 and 12 are also shown in Table 1.

[Experiment 9]
(Preparation and evaluation of Examples 13 and 14)
The temperature-detecting water-based ink of Example 1 and the temperature-sensing water-based ink of Example 9 were mixed at a mass ratio of "1: 1" to prepare the temperature-detecting water-based ink of Example 13. Further, the temperature-detecting water-based ink of Example 4 and the temperature-sensing water-based ink of Example 12 were mixed at a mass ratio of "1: 1" to adjust the temperature-detecting water-based ink of Example 14.

Since the temperature-sensing water-based inks of Examples 13 and 14 each contain two types of temperature-sensing materials, they are colorless in an environment maintained at 25 ° C., but once cooled to 4 ° C. or lower, they appear black. It becomes a temperature-detecting water-based ink that develops color and develops blue once heated to 50 ° C or higher.

A temperature indicator was produced in the same manner as in Example 1 using the temperature-sensing water-based ink of Example 13, and a temperature indicator was produced in the same manner as in Example 2 using the temperature-sensing water-based ink of Example 14.

A temperature change test (holding at 25 ° C for 10 minutes, cooling to 4 ° C, and then heating to 50 ° C) was performed on the prepared temperature indicator, and the color change of the printed characters was visually confirmed. It was evaluated as "pass" when it was colorless when kept at 25 ° C, and when it was cooled to 4 ° C and when it was heated to 50 ° C and the printed characters could be identified, it was evaluated as "pass", and the others were evaluated as "fail". .. As a result, Examples 13 and 14 were evaluated as "passed". The components and evaluation results of the temperature-detecting water-based inks of Examples 13 and 14 are also shown in Table 1.

The above-described embodiments and examples have been described for the purpose of assisting the understanding of the present invention, and the present invention is not limited to the specific configurations described. For example, it is possible to replace a part of the configuration of the embodiment with the configuration of common general technical knowledge of those skilled in the art, and it is also possible to add the configuration of common general technical knowledge of those skilled in the art to the configuration of the embodiment. That is, the present invention may delete, replace, or add other configurations to a part of the configurations of the embodiments and examples of the present specification without departing from the technical idea of the invention. It is possible.

1 ... Leuco dye, 2 ... Color developer, 3 ... Decolorizer, 4 ... Temperature detection material, 5 ... Surfactant,
10, 11 ... Temperature detection particles, 20 ... Water-based dispersion medium, 30 ... Water-soluble resin binder, 40 ... Other additives,
100 ... Temperature detection water-based ink.

Claims (13)

1. An ink characterized by containing a temperature detection material containing a leuco dye, a color developer and a decoloring agent, temperature detection particles containing a surfactant, and an aqueous dispersion medium.
2. In the ink according to claim 1,
   The temperature detection particles are characterized in that the surfactant coats the fine particles of the temperature detection material in which the leuco dye and the color developer are dispersed in the matrix of the decolorizing agent. ink.
3. In the ink according to claim 2,
   An ink characterized in that the surfactant is also present inside the temperature detection particles.
4. In the ink according to any one of claims 1 to 3.
   An ink characterized in that the median diameter of the temperature detection particles is 0.1 μm or more and 100 μm or less.
5. In the ink according to any one of claims 1 to 4.
   The ink is an ink characterized by further containing an additive.
6. In the ink according to claim 5,
   An ink characterized in that the additive is a water-soluble resin binder and / or a conductive agent and a leveling agent.
7. In the ink according to any one of claims 1 to 6.
   It contains a plurality of types of the temperature detection particles having different color development start temperatures.
   An ink characterized in that each of the plurality of types of temperature detection particles develops color when the temperature falls below a predetermined temperature.
8. In the ink according to any one of claims 1 to 6.
   It contains a plurality of types of the temperature detection particles having different color development start temperatures.
   An ink characterized in that each of the plurality of types of temperature detection particles develops color when the temperature rises above a predetermined temperature.
9. In the ink according to any one of claims 1 to 6.
   It contains a plurality of types of the temperature detection particles having different color development start temperatures.
   The plurality of types of temperature-detecting particles are an ink containing both temperature-detecting particles that develop color when the temperature falls below a predetermined temperature and temperature-sensing particles that develop color when the temperature exceeds a predetermined temperature.
10. The method for producing an ink according to any one of claims 1 to 9, wherein the temperature detection material is obtained by mixing, melting, and solidifying the leuco dye, the developer, and the decolorizing agent. The temperature detection material preparation process to be prepared and
    An emulsion preparation step of preparing an emulsion of the temperature detection material / surfactant by heating and stirring and mixing the temperature detection material and the solution of the surfactant, and
    A suspension preparation step of preparing a suspension of temperature-detecting particles / aqueous dispersion medium by stirring and mixing the heated emulsion and the heated aqueous dispersion medium and then cooling to room temperature while stirring.
    A method for producing an ink, which comprises.
11. In the method for producing an ink according to claim 10,
    A method for producing an ink, which further comprises an additive mixing step of mixing an additive with the suspension after the suspension preparation step.
12. In the method for producing ink according to claim 10 or 11.
    The temperature detection material preparation step is a method for producing an ink, which comprises a pulverization process for granulating the temperature detection material from agglomerates.
13. A temperature indicator with an ink marker printed on the printing substrate.
    A temperature indicator, wherein the ink is the ink according to any one of claims 1 to 9.

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