阅读说明：本技术 温度检测材料、使用其的温度检测油墨、温度指示器和物品管理系统 (Temperature detection material, temperature detection ink using same, temperature indicator, and article management system ) 是由 会田航平 森俊介 川崎昌宏 荒谷康太郎 于 2018-03-20 设计创作，主要内容包括：温度检测材料包含含有第一示温材料(示温材料A)的第一材料和含有第二示温材料(例如示温材料B)的第二材料,第一示温材料和第二示温材料含有隐色染料、显色剂和消色剂,在色密度－温度曲线具有磁滞特性,第一示温材料升温过程中的显色温度(T<Sub>a1</Sub>(T<Sub>a1A</Sub>))比升温过程中的消色温度(T<Sub>d1</Sub>(T<Sub>d1A</Sub>))低,熔化后,以规定的冷却速度以上被冷却至低于升温过程中的显色温度(T<Sub>a1</Sub>)时,成为非晶状态并保持为消色状态,第二示温材料的显色温度(T<Sub>a2</Sub>(T<Sub>a2B</Sub>))比升温过程中的消色温度(T<Sub>d2</Sub>(T<Sub>d2B</Sub>))低,升温过程中的显色温度(T<Sub>a1</Sub>)低于升温过程中的消色温度(T<Sub>d2</Sub>),显色温度(T<Sub>a2</Sub>)低于升温过程中的显色温度(T<Sub>a1</Sub>)。(The temperature detecting material comprises a first material containing a first temperature indicating material (temperature indicating material A) and a second material containing a second temperature indicating material (temperature indicating material B, for example), the first temperature indicating material and the second temperature indicating material contain a leuco dye, a developer and a decolorizer, and have a hysteresis characteristic in a color density-temperature curve, and a color developing temperature (T) of the first temperature indicating material during a temperature rise process a1 (T a1A ) Specific decoloring temperature (T) during temperature raising d1 (T d1A ) Low, after melting, is cooled to a low temperature at a predetermined cooling rate or higherColor development temperature (T) during temperature rise a1 ) When the temperature is in the amorphous state, the second temperature indicating material is kept in the decolored state, and the second temperature indicating material exhibits a color temperature (T) a2 (T a2B ) Specific decoloring temperature (T) during temperature raising d2 (T d2B ) Low color development temperature (T) during temperature rise a1 ) Below the decoloring temperature (T) during the temperature rise d2 ) Temperature of color development (T) a2 ) Lower than the developing temperature (T) during the temperature rise a1 )。)

1. A temperature-detecting material characterized by:

comprising a first material comprising a first temperature indicating material and a second material comprising a second temperature indicating material,

the first temperature indicating material and the second temperature indicating material contain a leuco dye, a color developer, and a decolorizer, have a hysteresis characteristic in a color density-temperature curve,

the color development temperature T of the first temperature display material in the temperature rise process_a1Specific decoloring temperature T in temperature rising process_d1Low, after melting, is cooled to a temperature lower than the color development temperature T in the temperature raising process at a predetermined cooling rate or more_a1When it is in the amorphous state, it is kept in the decolored state,

the color development temperature T of the second temperature indicating material_a2Specific decoloring temperature T in temperature rising process_d2The content of the organic acid is low,

the color development temperature T in the temperature rise process_a1Lower than the decoloring temperature T in the temperature raising process_d2，

The color development temperature T_a2Lower than the color development temperature T in the temperature rise process_a1。

2. The temperature-sensing material according to claim 1, wherein:

the color development temperature T of the second temperature indicating material_a2In order to reduce the color development temperature in the temperature reduction process,

the second temperature indicating material is cooled to the color temperature T higher than the color temperature T of the second temperature indicating material after being melted_a2Is higher than or lower than the color development temperature T of the first temperature display material in the temperature rise process_a1When the ink is discharged, the ink is in a liquid state and is kept in a decolored state.

3. The temperature-sensing material according to claim 1, wherein:

the color development temperature T of the second temperature indicating material_a2Is the developing temperature in the temperature rising process,

the second temperature indicating material is cooled to a temperature lower than the color temperature T at a predetermined cooling rate or more after being melted_a2When the state is amorphous, the state is kept as an achromatic state.

4. The temperature-detecting material according to claim 2, wherein:

further comprising a third material comprising a third temperature indicating material,

the third temperature indicating material contains leuco dye, developer and decolorizer, and has magnetic hysteresis characteristic in color density-temperature curve and color developing temperature Ta in the cooling process₃Specific decoloring temperature T in temperature rising process_d3The content of the organic acid is low,

after being melted, the third temperature indicating material is cooled to the color development temperature Ta higher than that in the temperature reduction process₃Is higher than or lower than the color development temperature T of the first temperature display material in the temperature rise process_a1When the ink is in a liquid state, the ink is kept in a decolored state,

the first, second and third temperature indicating materials have a T_a3＜T_a2＜T_a1、T_a1＜T_d1、T_a1＜T_d2、T_a1＜T_d3The relationship (2) of (c).

5. The temperature-detecting material according to any one of claims 1 to 4, wherein:

the first material and the second material further comprise a matrix material composed of a non-polar material,

the first material includes a matrix material having a melting point higher than that of the first temperature indicating material, and is formed into a phase separation structure in which the first temperature indicating material is dispersed in the matrix material,

the second material includes a matrix material having a melting point higher than that of the second temperature indicating material, and has a phase separation structure in which the second temperature indicating material is dispersed in the matrix material.

6. The temperature-detecting material according to any one of claims 1 to 4, wherein:

the first material is composed of microcapsules enclosing the first temperature indicating material,

the second material is composed of microcapsules enclosing the second temperature indicating material.

7. The temperature-detecting material according to claim 2, wherein:

the second material is a material having a phase separation structure in which the second temperature indicating material is dispersed in a matrix material made of a nonpolar material having a melting point higher than that of the second temperature indicating material, or a material made of microcapsules in which the second temperature indicating material is encapsulated.

8. The temperature-sensing material according to claim 4, wherein:

the second material is a material having a phase separation structure in which the second temperature indicating material is dispersed in a matrix material made of a nonpolar material having a melting point higher than that of the second temperature indicating material or a material made of microcapsules in which the second temperature indicating material is encapsulated,

the third material is a material having a phase separation structure in which the third temperature indicating material is dispersed in a matrix material made of a nonpolar material having a melting point higher than the melting point of the third temperature indicating material, or a material made of microcapsules in which the third temperature indicating material is encapsulated.

9. The temperature-detecting material according to any one of claims 1 to 3, wherein:

the melting points of the first material and the second material are 60-150 ℃.

10. A temperature detecting ink, characterized in that:

comprising the temperature-detecting material according to any one of claims 1 to 9 and a solvent,

the temperature detection ink is in an ink state.

11. A temperature indicator, characterized by:

comprising the temperature-detecting material according to any one of claims 1 to 9 and a substrate,

the temperature detection material is disposed on the substrate.

12. An article management system, comprising:

a management device for collecting color tone information of the temperature detection material according to any one of claims 1 to 9 attached to an article and managing an environment in which the article is placed based on the color tone information; and

a management terminal for obtaining article identification information identifying the article carried by the article and obtaining color tone information of the temperature detecting material,

the management terminal displays, on a display unit, a content of whether or not the color is changed when the obtained color tone information is obtained, and associates and transmits, to the management device, the content of whether or not the color is changed at the time when the article identification information and the color tone information are obtained.

13. The item management system of claim 12, wherein:

the management terminal displays, on the display unit, contents unsuitable for distribution of the article when the color is changed, and displays, on the display unit, contents suitable for distribution of the article when the color is not changed.

14. The item management system of claim 12, wherein:

in the management device, color density time information indicating a relationship between a color density of the temperature detecting material attached to the article and a time during which the article is placed in the environment is stored in a storage unit,

the management terminal obtains the color density time information based on the obtained article identification information from the management device, calculates a time when the environment is left, based on the color density of the obtained color tone information and the color density time information, displays the calculated time on a display unit, and associates and transmits the article identification information with the calculated time on the management device.

15. An article management system, comprising:

a management device for collecting color tone information of the temperature detection material according to any one of claims 1 to 9 attached to an article and managing an environment in which the article is placed based on the color tone information; and

a management terminal for obtaining article identification information identifying the article carried by the article and obtaining color tone information of the temperature detecting material,

in the management device, color density time information indicating a relationship between a color density of the temperature detecting material attached to the article and a time during which the article is placed in the environment is stored in a storage unit,

the management terminal obtains the color density time information based on the obtained article identification information from the management device, calculates a time to be left in the environment based on the color density of the obtained hue information and the color density time, displays the calculated time on a display unit, and associates and transmits the article identification information with the calculated time on the management device.

Technical Field

The present invention relates to a temperature detection material for checking the temperature of a temperature detection target or the like, and a temperature detection ink, a temperature indicator, and an article management system using the temperature detection material.

Background

In the distribution of fresh foods, frozen foods, or low-temperature-preserved pharmaceuticals such as vaccines and biological pharmaceuticals, a cold chain system that is maintained at a low temperature without interruption is required for production, transportation, and consumption. In practice, in order to measure and record the temperature at the time of circulation constantly, a data recorder capable of recording time and temperature continuously is often mounted on the transport container, and if the product is damaged, the responsibility thereof can be clarified.

In the case of managing the quality of individual products, there is a method of using a temperature indicator without using a data logger. The temperature indicator is not as accurate as a data recorder in recording, but can be attached to a single product, and when the temperature indicator is higher or lower than a predetermined temperature, the surface of the temperature indicator is dyed, so that a change in the temperature environment can be recognized.

Patent document 1 discloses a temperature indicating material using a leuco dye (leuco dye) as a temperature indicator capable of detecting a temperature increase or a temperature decrease.

Patent document 2 discloses a temperature indicating member that changes color irreversibly at ambient temperature due to crystallization-non-crystallization or phase separation-non-phase separation.

Disclosure of Invention

Problems to be solved by the invention

The temperature indicating material disclosed in patent document 1 can be changed (varied) in color by reversibly changing the color, and it is difficult to ensure temperature management during distribution.

The temperature indicating member disclosed in patent document 2 is irreversible at ambient temperature and can initialize a function, but only detects a temperature increase and cannot detect a temperature decrease.

When a temperature indicator is attached to a single product, there is a need to prevent forgery in the management of expensive products such as pharmaceuticals, and complete irreversibility is required for indicators after temperature deviation. However, in the management of low-cost products such as fresh foods, it is sufficient from the viewpoint of cost if irreversible at ambient temperature or less, and there is a need for reuse of a temperature indicator, transportation at room temperature, and storage at room temperature in addition to complete irreversible. Therefore, it is desired to initialize the function by a somewhat simple method.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a detection material capable of detecting a temperature increase and a temperature decrease and capable of initializing a function, and a temperature detection ink, a temperature indicator, and an article management system using the detection material.

Means for solving the problems

To achieve the above object, the present inventionThe temperature detecting material of the invention is characterized by comprising a first material containing a first temperature indicating material (for example, a temperature indicating material A) and a second material containing a second temperature indicating material (for example, a temperature indicating material A, a temperature indicating material B), wherein the first temperature indicating material and the second temperature indicating material contain a leuco dye, a color developer and a decolorizer, have a hysteresis characteristic in a color density-temperature curve, and the first temperature indicating material has a color temperature T during temperature rise_a1(e.g. color development temperature T)_a1A) Specific decoloring temperature T in temperature rising process_d1(e.g. decoloring temperature T)_d1A) Low, after melting, is cooled to a temperature lower than the color development temperature T during temperature rise at a predetermined cooling rate or more_a1When the second temperature indicating material is in an amorphous state, it is kept in a decolored state, and the second temperature indicating material has a color temperature T_a2(e.g. color development temperature T)_a2Ax、T_a2B) Specific decoloring temperature T in temperature rising process_d2(e.g. decoloring temperature T)_d2Ax、T_d2B) Low, color development temperature T in temperature rise_a1Below the decoloring temperature T during the temperature rise_d2Color temperature T_a2Lower than the color development temperature T in the temperature rising process_a1. Other embodiments of the present invention will be described in the following embodiments.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a detection material capable of detecting a temperature increase and a temperature decrease and initializing a function can be provided.

Drawings

Fig. 1 is a diagram showing a differential scanning calorimetry curve of the temperature indicating material according to the embodiment, in which (a) is the case of the temperature indicating material A, Ax, and (b) is the case of the temperature indicating material B, Bx.

FIG. 2 is a graph showing changes in color density of the temperature detecting material of example 1, wherein (a) is the case of the first temperature indicating material A, (B) is the case of the second temperature indicating material B, and (c) is the case of a combination of (a) and (B).

FIG. 3 is a graph showing changes in color density of the temperature detecting material of example 2, wherein (a) is the case of the first temperature indicating material A, (b) is the case of the second temperature indicating material Ax, and (c) is the case of a combination of (a) and (b).

Fig. 4 is a graph showing a change in color density of the temperature detection material for a combination of fig. 3 and the third temperature indicating material B.

FIG. 5 is a graph showing changes in color density of the temperature detecting material of example 3, wherein (a) is the case of the first temperature indicating material A, (B) is the case of the second temperature indicating material B, (c) is the case of the third temperature indicating material Bx, and (d) is the case of a combination of (a), (B), and (c).

FIG. 6 is a schematic diagram showing a phase separation structure of the temperature detection material, in which (a) is a colored state and (b) is a decolored state.

Fig. 7 is an optical micrograph of the temperature detection material, in which (a) shows a colored state and (b) shows a decolored state.

Fig. 8 is a schematic diagram showing the structure of the temperature indicator.

Fig. 9 is a schematic diagram showing a structure of a temperature indicator according to a modification of fig. 8.

Fig. 10 is a schematic diagram showing a structure of a temperature indicator according to another modification of fig. 8.

FIG. 11 is a diagram showing the production of a temperature indicator and the results of the verification thereof, wherein (a) shows the structure of the temperature indicator, (b) shows the structure of a base material for the temperature indicator, and (c) shows the results of the verification.

Fig. 12 is a diagram showing a configuration of the quality control system.

Fig. 13 is a diagram showing a configuration of the management server.

Fig. 14 is a diagram showing an example of the article information stored in the management server.

Fig. 15 is a diagram showing a relationship between the optimum temperature of the article and the control temperature, wherein (a) is a case of upper limit and lower limit control, (b) is a case of upper limit and lower limit control of order 2, (c) is a case of upper limit and lower limit control of order 2, (d) is a case of lower limit control of order 2, and (e) is a case of upper limit control of order 2.

Fig. 16 is a diagram showing temperature indicator information stored in the management server.

Fig. 17 is a diagram showing the appearance and structure of the quality control terminal.

Fig. 18 is a flowchart showing a process in the quality control terminal.

Fig. 19 is a diagram showing an example of a case where the distribution of quality management information stored in the management server is normal.

Fig. 20 is a diagram showing an example of a case where the distribution of quality management information stored in the management server is abnormal, where (a) is a case of "attention" call and (b) is a case of "stop" call.

Fig. 21 is a diagram showing another example of quality management information stored in the management server.

Detailed Description

Hereinafter, embodiments for carrying out the present invention (hereinafter, referred to as "embodiments") will be described in detail with reference to the accompanying drawings as appropriate. In the drawings, the same reference numerals are given to the common portions, and redundant description is omitted.

The structure of the temperature indicating material of the present embodiment will be described with reference to fig. 1 to 5. In the figure, the first temperature indicating material, the second temperature indicating material, and the third temperature indicating material respectively indicate the first, second, and third temperature indicating materials.

Temperature indicating material A, Ax: material which solidifies without crystallizing during rapid cooling

Temperature indicating material B, Bx: a material in a liquid state which is in a supercooled state when cooled,

subscripts with respect to temperature T indicate:

a: the color is developed, and the color is developed,

d: the color of the mixture is reduced, and the mixture is decolorized,

1. 2, 3: respectively a first temperature indicating material, a second temperature indicating material and a third temperature indicating material,

A. b, Ax, Bx: the kind of the temperature indicating material.

E.g. T_a1AThe first temperature indicating material is a material in which a temperature indicating material A is used and a color temperature T is indicated_a2AxThe second temperature indicating material indicates the color temperature at which the temperature indicating material Ax is used.

< temperature indicating Material >

As the temperature indicating material, a material whose color density reversibly changes according to a change in temperature (temperature increase/decrease) is used. The temperature indicating material comprises: a leuco dye as an electron donating compound, a color developer as an electron accepting compound, and a decolorizer for controlling the temperature range of color change.

Fig. 1 is a graph showing a Differential Scanning Calorimetry (DSC) curve of the temperature indicating material according to the embodiment, in which (a) is the case of the temperature indicating material A, Ax, and (b) is the case of the temperature indicating material B, Bx. With reference to fig. 1, the crystallization start temperatures of the temperature indicating material A, Ax and the temperature indicating material B, Bx will be described.

Fig. 1(a) shows a DSC curve of a material (temperature indicating material A, Ax) which solidifies in an amorphous state without crystallizing at the time of quenching. In the temperature lowering process (left arrow key (←) in the figure), no crystallization occurred, and therefore, no heat generation peak due to crystallization was observed. On the other hand, in the temperature rising process (right arrow key (→) of the figure), a heat generation peak due to crystallization was observed. T is_{a temperature rise}The temperature is the starting temperature in the temperature raising process (crystallization starting temperature in the temperature raising process). T is_dIs the melting point.

The starting temperature depends on the temperature rising rate or the elapsed time. The starting temperature appears at a low temperature when the temperature is raised at a low rate, the starting temperature appears at a high temperature when the temperature is raised at a high rate, or the melting point T does not appear at the starting temperature_dAnd (4) melting. The crystallization causes color development, and the starting temperature is set in accordance with the detection temperature and detection time required as a temperature detection material. For example, if the material is a temperature indicating material which starts to crystallize after 1 hour at a certain temperature, the material can be used as a starting temperature by setting the temperature as the starting temperature and detecting that 1 hour has elapsed at the starting temperature. In addition, T_gThe glass transition temperature. Below the glass transition temperature, crystallization does not start. In the case of a material which is easily crystallized, crystallization is easily performed at a temperature equal to or higher than the glass transition temperature, and therefore, the starting temperature and the glass transition temperature are often the same temperature.

Fig. 1(b) shows a DSC curve of a material (temperature indicating material B, Bx) that becomes a supercooled liquid when cooled after melting. T is_{a temperature reduction}The starting temperature of the heat generation peak due to crystallization during temperature lowering (crystallization starting temperature during temperature lowering). T is_dIs the melting point. Starting temperatureDepending on the cooling rate or elapsed time. The starting temperature occurs at a high temperature when the temperature is lowered at a low speed, and the starting temperature occurs at a low temperature when the temperature is lowered at a high speed. The crystallization causes color development, and the starting temperature is set in accordance with the detection temperature and detection time required as a temperature detection material. For example, if the material is a temperature indicating material which starts to crystallize after 1 hour at a certain temperature, the material can be used as a material whose temperature is set as a starting temperature and 1 hour at the starting temperature is detected. In the case of a material that is difficult to be in a supercooled state, the material is likely to crystallize at a temperature equal to or lower than the melting point, and therefore the starting temperature and the melting point are the same temperature. Such materials cannot be used as a temperature indicating material. That is, it is preferable that the material is easily in a supercooled state and has a large difference between the crystallization starting temperature and the melting point.

Hereinafter, a detection material capable of detecting a temperature increase and a temperature decrease and initializing a function will be described.

(example 1)

FIG. 2 is a graph showing changes in color density of the temperature detecting material of example 1, wherein (a) is the case of the first temperature indicating material A, (B) is the case of the second temperature indicating material B, and (c) is the case of a combination of (a) and (B). In each graph of fig. 2, the vertical axis represents color density, and the horizontal axis represents temperature.

Fig. 2(a) shows a temperature indicating material a (first temperature indicating material a) as a first temperature indicating material, and the first temperature indicating material a has hysteresis characteristics in terms of color density change. When a material that is difficult to crystallize is used as the decolorizer for the first temperature indicating material A, the decolorization temperature T of the first temperature indicating material A is set to be higher than the decolorization temperature T of the first temperature indicating material A_d1AThe above P1 in a molten state was quenched to a color development temperature Ta1_AIn the following case, the decolorizer can be maintained in an amorphous state by holding the developer encapsulated therein, and in a decolorized state. From this state, the temperature is raised to the color development temperature T in the temperature raising process_a1AIn the above case, the decolorizer crystallizes to develop color.

Fig. 2B shows a case of a temperature indicating material B (second temperature indicating material B) as a second temperature indicating material, and the second temperature indicating material B has hysteresis characteristics in terms of color density change. The second temperature indicating material B changes from the decoloring temperature T_d2BThe aboveWhen the state temperature of P1 in a molten state is lowered, the temperature is brought to a color development temperature T_a2BThe decoloring state is maintained. Becomes a color development temperature T_a2BIn the following cases, the decolorizer is in a crystalline state below the freezing point, and separates from the leuco dye and the color developer, whereby the leuco dye and the color developer are combined and develop color.

The present embodiment is intended to ensure temperature control of an article such as a commodity when the article is distributed. In the case of using a temperature detection material that reversibly changes color in response to a temperature change, even if the temperature temporarily rises or falls during circulation and the color of the temperature detection material changes, the color returns to its original state when the temperature falls or rises again during the circulation, and it is impossible to grasp whether or not the temperature has changed. However, if the material shows the discoloration phenomenon in fig. 2(a) and 2(b), the color is not easily restored, and thus a change in the temperature environment can be recognized.

FIG. 2(c) is a graph showing the change in color density of the temperature detecting material of example 1. In FIG. 2(c), the vertical axis represents color density, the horizontal axis represents temperature, and T represents_a1AIs the color development temperature, T, of the first temperature indicating material A_d1AIs the decoloring temperature, T, of the first temperature indicating material A_a2BIs the color development temperature, T, of the second temperature indicating material B_d2BIs the decoloring temperature of the second temperature indicating material B, and the cross hatched portion is the range of the control temperature of the article. By adjusting the color change width of the 2 first temperature indicating materials A and the second temperature indicating materials B, the change of the environmental temperature can be detected. Both temperature increase and temperature decrease can be detected by using the combination of the 2 kinds of temperature indicating materials. Further, by raising the temperature of each of the temperature indicating materials to a temperature equal to or higher than the melting point, the discolored state which is temporarily colored can be returned to the initial decolored state. Therefore, the material exhibits irreversibility at a temperature equal to or lower than the melting point of 2 materials, and a temperature deviation between the upper limit and the lower limit can be detected.

(example 2)

FIG. 3 is a graph showing changes in color density of the temperature detecting material of example 2, wherein (a) is the case of the first temperature indicating material A, (b) is the case of the second temperature indicating material Ax, and (c) is the case of a combination of (a) and (b). In each graph of fig. 3, the vertical axis represents color density, and the horizontal axis represents temperature.

Fig. 3(a) shows a temperature indicating material a (first temperature indicating material a) as a first temperature indicating material, which has hysteresis characteristics in terms of color density change, as in fig. 2 (a). The first temperature indicating material A has a decoloring temperature T from the first temperature indicating material A_d1AThe above P1 in a molten state is quenched to a color development temperature T_a1AIn the following case, the decolorizer can be maintained in an amorphous state by holding the developer encapsulated therein, and in a decolorized state. From this state, the temperature is raised to the color development temperature T in the temperature raising process_a1AIn the above case, the decolorizer crystallizes to develop color.

Fig. 3(b) shows a case of the temperature indicating material Ax (second temperature indicating material Ax) as the second temperature indicating material, and the second temperature indicating material Ax has a hysteresis characteristic in a change in color density. The second temperature indicating material Ax has a temperature T equal to or lower than the erasing temperature T of the second temperature indicating material A_d2AxThe above P1 in a molten state is quenched to a color development temperature T_a2AxIn the following case, the decolorizer can be maintained in an amorphous state by holding the developer encapsulated therein, and in a decolorized state. From this state, the temperature is raised to the color development temperature T in the temperature raising process_a2AxIn the above case, the decolorizer crystallizes to develop color.

FIG. 3(c) is a graph showing the change in color density of the temperature detecting material of example 2. In FIG. 3(c), the vertical axis represents color density, the horizontal axis represents temperature, and T_a1AIs the color development temperature, T, of the first temperature indicating material A_d1AIs the decoloring temperature, T, of the first temperature indicating material A_a2AxIs the color development temperature, T, of the second temperature indicating material Ax_d2AxIs the erasing temperature of the second temperature indicating material Ax, and the cross hatched portion and the hatched portion are the range of the control temperature of the article. By adjusting the color development temperatures of the 2 types of first temperature indicating material a and second temperature indicating material Ax, a plurality of temperature detections at the time of temperature rise can be performed.

Fig. 4 is a graph showing a change in color density of the temperature detection material for a combination of fig. 3 and the third temperature indicating material B. In FIG. 4, the vertical axis represents color density, the horizontal axis represents temperature, and T represents_a1AIs the color development temperature, T, of the first temperature indicating material A_d1AIs the first temperature indicationDecoloring temperature, T, of Material A_a2AxIs the color development temperature of the second temperature indicating material Ax. T is_d2AxIs the erasing temperature, T, of the second temperature indicating material Ax_a3BIs the color development temperature, T, of the third temperature indicating material B_d3BThe color erasing temperature of the third temperature indicating material B, and the cross hatching portion and the hatching portion are the range of the control temperature of the article.

By adjusting the color change widths of the second temperature indicating material Ax and the third temperature indicating material B among the 3 types, it is possible to detect whether or not the ambient temperature has changed, and it is possible to detect a plurality of temperatures on the temperature rise process side.

(example 3)

FIG. 5 is a graph showing changes in color density of the temperature detecting material of example 3, wherein (a) is the case of the first temperature indicating material A, (B) is the case of the second temperature indicating material B, and (c) is the third temperature indicating material B_xThe case (d) is a combination of (a), (b) and (c).

Fig. 5(a) shows a temperature indicating material a (first temperature indicating material a) as a first temperature indicating material, which has hysteresis characteristics in terms of color density change, as in example 1. The first temperature indicating material A has a decoloring temperature T from the first temperature indicating material A_d1AThe above P1 in a molten state is quenched to a color development temperature T_a1AIn the following case, the decolorizer can be maintained in an amorphous state by holding the developer encapsulated therein, and in a decolorized state. From this state, the temperature is raised to the color development temperature T in the temperature raising process_a1AIn the above case, the decolorizer crystallizes to develop color.

Fig. 5(B) shows a temperature indicating material B (second temperature indicating material B) as a second temperature indicating material, which has hysteresis characteristics in terms of color density change, as in example 1. The second temperature indicating material B changes from the decoloring temperature T_d2BWhen the state temperature of the molten P1 is lowered, the decolored state is maintained up to the color development temperature T_a2B. Becomes a color development temperature T_a2BIn the following cases, the decolorizer is in a crystalline state below the freezing point, and separates from the leuco dye and the color developer, whereby the leuco dye and the color developer are combined and develop color.

FIG. 5C shows a temperature indicating material Bx as a third temperature indicating material (third embodiment)Temperature material Bx), the third temperature indicating material B has a hysteresis characteristic in color density change. The third temperature indicating material Bx has the same color temperature change hysteresis characteristic as the second temperature indicating material B, and changes from the decoloring temperature T_d3BxWhen the state temperature of the molten P1 is lowered, the decolored state is maintained up to the color development temperature T_a3Bx. Becomes a color development temperature T_a3BxIn the following cases, the decolorizer is in a crystalline state below the freezing point, and separates from the leuco dye and the color developer, whereby the leuco dye and the color developer are combined and develop color.

FIG. 5(d) is a graph showing the change in color density of the temperature detecting material of example 3. In FIG. 5(d), the vertical axis represents color density, the horizontal axis represents temperature, and T_a1AIs the color development temperature, T, of the first temperature indicating material A_d1AIs the decoloring temperature, T, of the first temperature indicating material A_a2BIs the color development temperature, T, of the second temperature indicating material B_d2BIs the decoloring temperature, T, of the second temperature indicating material B_a3BxIs the color development temperature, T, of the third temperature indicating material Bx_d3BxThe color erasing temperature of the third temperature indicating material Bx, and the cross hatching part and the diagonal hatching part are the range of the control temperature of the article. Through the width that discolours of first temperature indicating material A, second temperature indicating material B in the adjustment these 3 kinds, can detect ambient temperature and have or not change, moreover, in the cooling process side, can carry out a plurality of temperature detection.

The above examples are summarized as follows.

The temperature detection material of the present embodiment includes a first material containing a first temperature indicating material and a second material containing a second temperature indicating material, and the first temperature indicating material and the second temperature indicating material contain a leuco dye, a developer, and a decolorizer, and have a hysteresis characteristic in a color density-temperature curve. In the case of the first temperature indicating material, the color development temperature T in the temperature rise process_a1(e.g. T)_a1A) Specific decoloring temperature T in temperature rising process_d1(e.g. T)_d1A) Low, after melting, is cooled to a temperature lower than the color development temperature T during temperature rise at a predetermined cooling rate or more_a1When the second temperature indicating material is in an amorphous state, it is kept in a decolored state, and the second temperature indicating material has a color temperature T_a2(e.g. T)_a2B、T_a2Ax) Specific decoloring temperature T in temperature rising process_d2(e.g. T)_d2B、T_d2Ax) Low, color development temperature T in temperature rise_a1Below the decoloring temperature T during the temperature rise_d2Color temperature T_a2Lower than the color development temperature T in the temperature rising process_a1。

In FIG. 2, the color temperature T of the second temperature indicating material_a2(e.g. T)_a2B) For reducing the color development temperature in the temperature reduction process, the second temperature indicating material is cooled to be lower than the color development temperature T of the second temperature indicating material after being melted_a2Is higher than or lower than the color development temperature T in the temperature rise process of the first temperature display material_a1When the ink is discharged, the ink is in a liquid state and is kept in a decolored state.

In FIG. 3, the color temperature T of the second temperature indicating material_a2(e.g. T)_a2Ax) The second temperature indicating material is cooled to a temperature lower than the color temperature T at a predetermined cooling rate or more after being melted to the color temperature T during the temperature raising process_a2When the state is amorphous, the state is kept as an achromatic state.

In fig. 4 and 5, the temperature detecting material of the present embodiment further includes a third material containing a third temperature indicating material, the third temperature indicating material containing a leuco dye, a color developer, and a decolorizer, having a hysteresis characteristic in a color density-temperature curve, and having a color development temperature T during temperature reduction_a3(e.g. T)_a3B、T_a3Bx) Specific decoloring temperature T in temperature rising process_d3After the third temperature indicating material is melted, the third temperature indicating material is cooled to the color development temperature T in the process of temperature reduction_a3Is higher than or lower than the color development temperature T in the temperature rise process of the first temperature display material_a1When the temperature is changed to a liquid state, the liquid state is maintained in a decolored state, and the first temperature indicating material, the second temperature indicating material, and the third temperature indicating material have T_a3＜T_a2＜T_a1、T_a1＜T_d1、T_a1＜T_d2、T_a1＜T_d3The relationship (2) of (c).

Next, the leuco dye, the developer, and the decolorizer of each of the temperature indicating materials will be described.

(leuco dye)

The leuco dye is an electron donating compound, and conventionally known leuco dyes used for pressure-sensitive copying papers and thermal recording papers can be used. Examples thereof include triphenylmethane phthalide type, fluorane type, phenothiazine type, indolylphthalein type, leucoauramine type (leucoauramine), spiropyrane type, rhodamine lactam type, triphenylmethane type, triazene type, spirodihydroisobenzofuran xanthene type, naphtholactam type, azomethine type, and the like. Specific examples of leuco dyes include 9- (N-ethyl-N-isopentylamino) spiro [ benzo [ A ] xanthene-12, 3 '-phthalide ], 2-methyl-6- (N-p-tolyl-N-ethylamino) -fluoran 6- (diethylamino) -2- [ (3-trifluoromethyl) anilino ] xanthene-9-spiro-3' -phthalide, 3-bis (p-diethylaminophenyl) -6-dimethylaminophthalide, 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-dihydrospiro [ 11H-chromeno [2,3-g ] quinoline-11, 3' -phthalide ].

The temperature indicating material may use more than 2 kinds of leuco dyes in combination.

(color-developing agent)

The color developer is brought into contact with the electron-donating leuco dye to change the structure of the leuco dye, thereby developing a color. As the developer, a known developer can be used as a developer used for thermal recording paper, pressure-sensitive copying paper, or the like. Specific examples of such a developer include phenols such as benzyl 4-hydroxybenzoate, 2' -biphenol, 1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, 2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, bisphenol a, bisphenol F, bis (4-hydroxyphenyl) sulfide, p-hydroxybenzoate, and gallate. The color-developer is not limited to these, and any compound may be used as long as it is an electron acceptor and can change the color of the leuco dye. Further, metal salts of carboxylic acid derivatives, salicylic acid and metal salts of salicylic acid, sulfonic acids, sulfonic acid salts, phosphoric acids, metal phosphate salts, acidic phosphate esters, metal acidic phosphate salts, phosphorous acids, metal phosphorous acid salts, and the like can be used. Particularly, a substance having high compatibility with the leuco dye or a decolorizer described later is preferable, and an organic color developer such as benzyl 4-hydroxybenzoate, 2' -biphenol, bisphenol a, or gallic acid ester is preferable.

The temperature indicator material of the present embodiment may use 1 kind of these color developers, or 2 or more kinds in combination. The color density of the leuco dye in color formation can be adjusted by combining the color-developing agents. The amount of the color developer used is selected according to the desired color density. For example, the amount of the leuco dye may be selected from the range of about 0.1 to 100 parts by weight based on 1 part by weight of the leuco dye.

(decolorizer)

The decolorizer is a compound capable of dissociating the binding between the leuco dye and the color developer, and is a compound capable of controlling the color development temperature of the leuco dye and the color developer. Generally, the leuco dye is cured in a state where the decolorizer phase separates in a temperature range of a colored state. In addition, in the temperature range in which the leuco dye is in the decolorized state, the decolorizer melts and functions to dissociate the binding between the leuco dye and the developer. Therefore, the state change temperature of the decolorizer is important for temperature control of the temperature indicating material.

As a material of the decolorizer, a material capable of dissociating the binding between the leuco dye and the color developer can be widely used. Various materials may be used as decolorizers as long as they have low polarity, do not exhibit color developability with respect to the leuco dye, and have high polarity to the extent that the leuco dye and the developer are dissolved. Typically, various organic compounds such as a hydroxyl compound, an ester compound, a peroxide, a carbonyl compound, an aromatic compound, an aliphatic compound, a halogen-containing compound, an amino compound, an imino compound, an N-oxo compound, a hydroxylamine compound, a nitro compound, an azo compound, a diazo compound, an azide compound, an ether compound, an oil-and-fat compound, a sugar compound, a peptide compound, a nucleic acid compound, a alkaloid compound, and a steroid compound can be used. Specifically, there may be mentioned: glycerol tricarbamate, isopropyl myristate, m-toluate, diethyl sebacate, dimethyl adipate, 1, 4-diacetoxybutane, decyl decanoate, diethyl phenylmalonate, diisobutyl phthalate, triethyl citrate, benzyl butyl phthalate, butyl phthalate butyl glycolate, methyl N-methylaminobenzoate, ethyl aminobenzoate, 2-hydroxyethyl salicylate, methyl nicotinate, butyl 4-aminobenzoate, methyl p-toluate, ethyl 4-nitrobenzoate, 2-phenylethyl phenylacetate, benzyl cinnamate, methyl acetoacetate, geranyl acetate, dimethyl succinate, dimethyl sebacate, diethyl oxaloacetate, monoolein, butyl palmitate, ethyl stearate, methyl palmitate, methyl stearate, methyl N-methylate, N-methylanthranilate, ethyl salicylate, ethyl nicotinate, ethyl nicotin, Linalyl acetate, di-n-octyl phthalate, benzyl benzoate, diethylene glycol dibenzoate, methyl p-anisate, m-toluyl acetate, cinnamyl cinnamate, 2-phenylethyl propionate, butyl stearate, ethyl myristate, methyl anthranilate, neryl acetate, isopropyl palmitate, ethyl 4-fluorobenzoate, cyclandelate (isomer mixture), delphine, ethyl 2-bromopropionate, glyceryl tricaprylate, ethyl levulinate, cetyl palmitate, t-butyl acetate, 1-ethylene glycol diacetate, dimethyl oxalate, glyceryl tristearate, methyl acetylsalicylate, benzylidene diacetate, methyl 2-benzoylbenzoate, ethyl 2, 3-dibromobutyrate, ethyl 2-furancarboxylate, ethyl acetate, methyl acetate, ethyl propionate, ethyl acetylacetonate, ethyl vanillate, dimethyl itaconate, methyl 3-bromobenzoate, monoethyl adipate, dimethyl adipate, 1, 4-diacetoxybutane, diethylene glycol diacetate, ethyl palmitate, diethyl terephthalate, phenyl propionate, phenyl stearate, 1-naphthyl acetate, methyl behenate, methyl arachinate, methyl 4-chlorobenzoate, methyl sorbate, ethyl isonicotinate, dimethyl dodecanoate, methyl heptadecanoate, ethyl alpha-cyanocinnamate, ethyl N-phenylglycinate, diethyl itaconate, methyl picolinate, methyl isonicotinate, methyl DL-mandelate, methyl 3-aminobenzoate, methyl 4-methylsalicylate, diethyl benzylidene malonate, isoamyl DL-mandelate, triethyl methanetricarboxylate, Diethyl formylaminomalonate, 1, 2-bis (chloroacetoxy) ethane, methyl pentadecanoate, ethyl arachidate, ethyl 6-bromohexanoate, monoethyl pimelate, hexadecyl lactate, ethyl diphenylglycolate, Mefenpyr-diethyl, procaine, dicyclohexyl phthalate, 4-tert-butylphenyl salicylate, isobutyl 4-aminobenzoate, butyl 4-hydroxybenzoate, tripalmitin, 1, 2-diacetoxybenzene, dimethyl isophthalate, monoethyl fumarate, methyl vanilate, methyl 3-amino-2-thiophenecarboxylate, etomidate, cloquintocet-mexyl, methyl diphenylglycolate, diphenyl phthalate, phenyl benzoate, propyl 4-aminobenzoate, Ethylene dibenzoate, triacetin, ethyl pentafluoropropionate, methyl 3-nitrobenzoate, 4-nitrophenyl acetate, methyl 3-hydroxy-2-naphthoate, trimethyl citrate, ethyl 3-hydroxybenzoate, methyl 3-hydroxybenzoate, trimebutine (trimebutine), 4-methoxybenzyl acetate, pentaerythritol tetraacetate, methyl 4-bromobenzoate, ethyl 1-naphthylacetate, 5-nitro-2-furfural diacetate, ethyl 4-aminobenzoate, propyl p-hydroxybenzoate, 1,2, 4-triacetoxybenzene, methyl 4-nitrobenzoate, diethyl acetamidomalonate, pentaethylamide bromide, 2-naphthyl benzoate, dimethyl fumarate, phenine hydrochloride (adrihehenatehydochloride), Benzyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, vinyl butyrate, vitamin K4, methyl 4-iodobenzoate, methyl 3, 3-dimethylacrylate, propyl gallate, 1, 4-diacetoxybenzene, diethyl mesooxalate, dimethyl 1, 4-cyclohexanedicarboxylate (cis-, Trans-mixture), triethyl 1,1, 2-ethaneditricarboxylate, dimethyl hexafluoroglutarate, pentyl benzoate, ethyl 3-bromobenzoate, ethyl 5-bromo-2-chlorobenzoate, bis (2-ethylhexyl) phthalate, diethyl allylmalonate, diethyl bromomalonate, diethyl ethoxymethylenemalonate, diethyl ethylmalonate, diethyl fumarate, diethyl maleate, diethyl malonate, sodium hydrogen phosphate, sodium, Diethyl phthalate, dimethyl 1, 3-acetonedicarboxylate, dimethyl phthalate, ethyl 3-aminobenzoate, ethyl benzoate, ethyl 4- (dimethylamino) benzoate, ethyl nicotinate, ethyl phenylpropionate, ethyl pyridine-2-carboxylate, ethyl 2-pyridylacetate, ethyl 3-pyridylacetate, methyl benzoate, ethyl phenylacetate, pentyl 4-hydroxybenzoate, 2, 5-diacetoxytoluene, ethyl 4-oxazolecarboxylate, trimethyl 1,3, 5-cyclohexanetricarboxylate (cis-, Trans-mixture), methyl 3- (chlorosulfonyl) -2-thiophenecarboxylate, pentaerythritol distearate, benzyl laurate, diethyl acetylenedicarboxylate, phenyl methacrylate, dimethyl phthalate, ethyl 3-aminobenzoate, ethyl 3-pyridinecarboxylate, methyl 3-pyridylacetate, methyl 2-thiazolylacetate, benzyl laurate, diethyl acetylenedicarboxylate, methyl nicotinate, ethyl, Benzyl acetate, dimethyl glutarate, ethyl 2-oxycyclohexanecarboxylate, ethyl phenylcyanoacetate, ethyl 1-piperazinecarboxylate, methyl benzoylformate, methyl phenylacetate, phenyl acetate, diethyl succinate, tributyrin, diethyl methylmalonate, dimethyl oxalate, diethyl 1, 1-cyclopropanedicarboxylate, dibenzyl malonate, methyl 4-tert-butylbenzoate, ethyl 2-oxycyclopentanecarboxylate, methyl cyclohexanecarboxylate, ethyl 4-methoxyphenylacetate, methyl 4-fluorobenzoylacetate, dimethyl maleate, methyl p-formylbenzoate, ethyl 4-bromobenzoate, methyl 2-iodobenzoate, ethyl 3-furancarboxylate, diallyl phthalate, Benzyl bromoacetate, dimethyl bromomalonate, methyl m-toluate, diethyl 1, 3-acetonedicarboxylate, methyl phenylpropionate, 1-naphthyl butyrate, ethyl o-toluate, methyl 2-oxocyclopentanecarboxylate, isobutyl benzoate, ethyl 3-phenylpropionate, di-tert-butyl malonate, dibutyl sebacate, diethyl adipate, diethyl terephthalate, dipropyl phthalate, 1-ethanediol diacetate, diisopropyl adipate, diisopropyl fumarate, ethyl cinnamate, 2-ethylhexyl 2-cyano-3, 3-diphenylacrylate, neopentyl glycol diacrylate, glycerol trioleate, ethyl benzoylacetate, ethyl p-anisate, diethyl suberate, sorbitan tristearate, sorbitan monostearate, di-n-butyl acetate, di-n-butyl adipate, diethyl 3-phenylpropionate, di-tert-butyl malonate, dibutyl phthalate, diethyl sebacate, glycerol trioleate, ethyl benzoylacetate, ethyl p-anisate, Stearamide, glyceryl monostearate, glyceryl distearate, 3- (tert-butoxycarbonyl) phenylboronate, racecadotril (racecadotril), 4- [ (6-acryloyloxy) hexyloxy ] -4 '-cyanobiphenyl, 2- (dimethylamino) vinyl 3-pyridinone, stearyl acrylate, ethyl 4-bromophenylacetate, dibenzyl phthalate, methyl 3, 5-dimethoxybenzoate, eugenol acetate, didodecyl 3, 3' -thiodipropionate, vanillin acetate, diphenyl carbonate, ethyl anilinecarboxylate (ethyl oxanilate), methyl terephthalate, dimethyl 4-nitrophthalate, (4-nitrobenzoyl) ethyl acetate, dimethyl nitroterephthalate, methyl 2-methoxy-5- (methylsulfonyl) benzoate, and mixtures thereof, Methyl 3-methyl-4-nitrobenzoate, dimethyl 2, 3-naphthalenedicarboxylate, bis (2-ethylhexyl) adipate, 4 '-acetoxyacetophenone, Trans-3-benzoylacrylic acid ethyl ester, coumarin-3-carboxylic acid ethyl ester, BAPTA tetraethyl ester, methyl 2, 6-dimethoxybenzoate, di-tert-butyl iminodicarboxylate, benzyl p-benzyloxybenzoate, methyl 3,4, 5-trimethoxybenzoate, methyl 3-amino-4-methoxybenzoate, diethylene glycol distearate, ditetradecyl 3, 3' -thiodipropionate, ethyl 4-nitrophenylacetate, methyl 4-chloro-3-nitrobenzoate, 1, 4-dipropoyloxybenzene, dimethyl terephthalate, dimethyl ester of dimethyl-N-hydroxyformate, methyl ester of dimethyl-N-hydroxyiminodicarboxylate, methyl p-benzyloxybenzoate, methyl 3, 4-trimethoxy benzoate, methyl ester of dimethyl-N-hydroxy, Ester compounds such as ethyl 4-nitrocinnamate, dimethyl 5-nitroisophthalate, triethyl 1,3, 5-benzenetricarboxylate, diethyl N- (4-aminobenzoyl) -L-glutamate, 2-methyl-1-naphthyl acetate, 7-acetoxy-4-methylcoumarin, methyl 4-amino-2-methoxybenzoate, 4 '-diacetoxybiphenyl, dimethyl 5-aminoisophthalate, diethyl 1, 4-dihydro-2, 6-dimethyl-3, 5-pyridinedicarboxylate, and dimethyl 4, 4' -biphenyldicarboxylate; cholesterol, cholesterol bromide, beta-estradiol, methylandrostanediol, pregnenolone, cholesteryl benzoate, cholesteryl acetate, cholesteryl linoleate, cholesteryl palmitate, cholesteryl stearate, cholesteryl n-caprylate, cholesteryl oleate, 3-chlorocholestene, Trans-cholesteryl cinnamate, cholesteryl decanoate, cholesteryl hydrocinnamate, cholesteryl laurate, cholesteryl butyrate, cholesteryl formate, cholesteryl heptanoate, cholesteryl hexanoate, cholesteryl hydrogen succinate, cholesteryl myristate, cholesteryl propionate, cholesteryl valerate, cholesteryl hydrogen phthalate, cholesteryl phenylacetate, cholesteryl chloroformate, cholesteryl 2, 4-dichlorobenzoate, cholesteryl nonanoate, cholesteryl nonyl carbonate, cholesteryl heptyl carbonate, pregnenolone, cholesteryl benzoate, cholesteryl acetate, cholesteryl laurate, cholesterol, Cholesterol oleyl carbonate, cholesterol methyl carbonate, cholesterol ethyl carbonate, cholesterol isopropyl carbonate, cholesterol butyl carbonate, cholesterol isobutyl carbonate, cholesterol amyl carbonate, cholesterol n-octyl carbonate, cholesterol hexyl carbonate, allylestriol, altrenogest, 9(10) -dehydronandrolone (dehydronandrolone), estrone, ethinyl estradiol, estriol benzoate, beta-estradiol 17-cypionate, 17-valeric acid beta-estradiol, alpha-estradiol, 17-heptanoic acid beta-estradiol, pregrinone, mestranol (mestranol), 2-methoxy-beta-estradiol, nanolone, (-) -methylynolone, ethinyl estradiol ether (quinestrol), trenolone (trenbolone), tibolone (tibolone), androlone (androlone), nobolone (dinolone, and the like, Androsterone, abiraterone (abiraterone), abiraterone acetate, dehydroepiandrosterone acetate, ethisterone, epiandrosterone, 17 beta-hydroxy-17-methylandrostane-1, 4-dien-3-one, methylandrostenediol, methyltestosterone, Δ 9(11) -methyltestosterone, 1 alpha-methylandrostane-17 beta-ol-3-one, 17 alpha-methylandrostane-17 beta-ol-3-one, stanozolol (stanozolol), testosterone propionate, allyl alcohol, 16-dehydropregnenolone acetate, 16, 17-epoxypregnenolone acetate, 11 alpha-hydroxyprogesterone, 17 alpha-hydroxyprogesterone hexanoate, 17 alpha-hydroxyprogesterone, pregnenolone acetate, 17 alpha-hydroxyprogesterone acetate, Megestrol acetate, medroxyprogesterone acetate, pregnenolone acetate, 5 beta-pregnan-3 alpha, 20 alpha-diol, budesonide, corticosterone, cortisone acetate, cortisone, 11-deoxycortisol, deoxycorticosterone acetate, deflazacort, hydrocortisone acetate, hydrocortisone 17-butyrate, 6 alpha-methylprednisolone, prednisolone acetate, sodium deoxycholate, sodium cholate, methyl hyodeoxycholate, beta-cholestanol, cholesterol-5 alpha, 6 alpha-epoxide, diosgenin, ergosterol, beta-sitosterol, stigmasterol acetate, and other steroids. These compounds are preferably contained from the viewpoint of compatibility with the leuco dye and the color developer. Of course, the compound is not limited to these compounds, and any material may be used as long as it can dissociate the binding between the leuco dye and the color developer.

These decolorizers may be used in combination of 1 kind or 2 or more kinds. By combining the decolorizer, the freezing point and the melting point can be adjusted.

Of course, the compound is not limited to these compounds, and other compounds can be exemplified. The state change temperature of the decolorizer is important, and the decolorizer is formed into an amorphous state by rapid cooling, and therefore, as a decolorizer for a temperature indicating material for detecting a deviation of the upper limit temperature, it is necessary to make the decolorizer amorphous in the vicinity of the glass transition temperature without crystallizing in the rapid cooling process. Therefore, a material which is difficult to crystallize is preferable. If the quenching rate is made very high, most of the material is in an amorphous state, but if the practical use is considered, a material that is difficult to crystallize to the extent that the material is formed in an amorphous state by quenching using a general-purpose cooling device is preferable. More preferably, the material is formed into an amorphous state in a natural cooling process from a molten state of a melting point or higher, and is hard to crystallize. As the conditions, it is preferable that the decolorizer is formed in an amorphous state when cooled from the melting point to the glass transition temperature at a rate of 1 ℃/min or more, and it is most preferable that the decolorizer is formed in an amorphous state when cooled from the melting point to the glass transition temperature at a rate of 20 ℃/min or more.

When the decolorizer is in the supercooled state at a temperature not higher than the melting point and is present in a liquid state, the decolorizer of the temperature indicating material for detecting the deviation of the lower limit temperature is preferably a material having a wide temperature range in the supercooled state, that is, a large temperature difference between the solidification point and the melting point of the decolorizer. The temperature of the melting point or the freezing point depends on the temperature control range to be controlled.

In order to initialize the function, it is necessary to increase the temperature to the melting point or higher of the decolorizer of the temperature indicating material for detecting the upper limit temperature deviation and the decolorizer of the temperature indicating material for detecting the lower limit temperature deviation. The initialization temperature of the function needs to be high enough to be difficult to occur near the control temperature, and in consideration of the practical use, it is preferable that the temperature range be heatable by a general-purpose heating device. In addition, as the temperature detecting material, a matrix material or a base material for an indicator is used in order to protect the temperature indicating material, and therefore, heat resistance of these materials is also required to be considered. Specifically, it is preferably from about 40 ℃ to about 200 ℃, and most preferably from about 60 ℃ to about 150 ℃.

< temperature detecting Material >

There are a plurality of ways to use the combination of the temperature indicating materials as the temperature detecting material. When the upper limit detection material and the lower limit detection material are mixed, their functions are inhibited, and therefore, a separate structure is required. In addition, since the lower limit detection material develops color by crystallization of a liquid, the structure of the temperature indicating material changes. Therefore, from the viewpoint of handling, it is necessary to form a protective liquid.

From this viewpoint, a method of protecting the temperature indicating material with microcapsules is generally employed. The mixture can be subjected to simultaneous detection of the upper limit detection and the lower limit detection by microencapsulating and mixing the temperature indicating material for upper limit detection and the temperature indicating material for lower limit detection, respectively. However, the microencapsulation is not limited thereto. For example, a temperature indicating material can be used in the same manner as a microcapsule by protecting the material with a matrix material that does not exhibit coloring or decoloring effects to form a solid material (phase-separated structure). Further, the temperature indicating material for upper limit detection develops color by crystallization in an amorphous state. Therefore, discoloration occurs in a solid state. Therefore, as the upper limit detection material, a single temperature indicating material may be used. However, in order to initialize the function, the temperature indicating material needs to be melted and becomes liquid in this state, which makes the operation difficult.

Thus, for example, a microcapsule temperature indicating material, a phase separation structure temperature indicating material, or a temperature indicating material alone is used as the upper limit detection material, and a microcapsule temperature indicating material, a phase separation structure temperature indicating material is used as the lower limit detection material, and these materials are mixed, whereby a solid material capable of simultaneous detection of the upper limit detection and the lower limit detection can be obtained.

The solid material may be mixed with a solvent to form an ink or a paint. When a microencapsulated temperature indicating material, a temperature indicating material having a phase-separated structure, or a temperature indicating material monomer is used as a solid material, it is possible to form an ink or a coating material by selecting a solvent having resistance to these materials.

Further, even if the temperature indicating material is not made into a solid material, the temperature indicator can be used as an indicator by being wrapped with a base material such as resin, glass, or a porous material, thereby enabling simultaneous detection of the upper limit and the lower limit. In this case, materials solidified by microencapsulation, phase separation structure formation, or the like may be used.

< microencapsulation >

Microencapsulation can improve the environmental resistance of the composition to light, humidity, and the like as described above, and can stabilize storage stability, discoloration characteristics, and the like. Moreover, microencapsulation can prevent the leuco dye, the developer, and the decolorizer from being affected by other compounds such as resin agents and additives when preparing inks and coatings.

Various known methods can be applied to microencapsulation. Examples thereof include, but are not limited to, emulsion polymerization, suspension polymerization, coacervation, interfacial polymerization, and spray drying. In addition, 2 or more different methods may be combined.

Examples of the resin coating film used for the microcapsule include, but are not limited to, a urea resin coating film composed of a polyamine and a carbonyl compound, a melamine resin coating film composed of a melamine-formaldehyde prepolymer, a methylolmelamine prepolymer, and a methylated melamine prepolymer, a polyurethane resin coating film composed of a polyvalent isocyanate and a polyvalent alcohol compound, an amide resin coating film composed of a polyvalent acid chloride and a polyamine, and a vinyl resin coating film composed of various monomers such as vinyl acetate, styrene, (meth) acrylate, acrylonitrile, and vinyl chloride. Further, by performing surface treatment on the formed resin film, additional treatment such as adjustment of surface energy at the time of formation of ink or paint can be performed to improve dispersion stability of the microcapsules.

Further, the diameter of the microcapsule is preferably in the range of about 0.1 to 100 μm, more preferably 0.1 to 10 μm, because the device suitability, the storage stability, and the like are problems.

< phase separation structurization >

The phase separation structure is a structure in which a leuco dye, a developer, and a decolorizer, which are temperature indicating materials, are dispersed in a matrix material and made into a solid material. Thus, storage stability and stabilization of discoloration characteristics similar to those of microcapsules can be achieved by a simple method other than microencapsulation. Further, when the ink, the coating material or the like is prepared, the leuco dye, the developer, and the decolorizer can be inhibited from being affected by other compounds such as a resin agent and an additive.

(matrix Material)

The matrix material is required to be a material that does not impair the color developability or color developability of the temperature indicating material when mixed with the temperature indicating material. Therefore, a material which does not exhibit color rendering properties by itself is preferable. As such a material, a nonpolar material which is not an electron acceptor can be used.

In order to form a phase separation structure in which a temperature indicating material is dispersed in a matrix material, it is necessary to use a material satisfying the following 3 conditions as the matrix material. The 3 conditions are: is in a solid state at the use temperature of the temperature detection material; the melting point is higher than that of the temperature indicating material; is a material having low compatibility with the leuco dye, the decolorizer and the coloring material. This is because the temperature detection function is impaired in a state where the leuco dye, the color developer, the decolorizer, or any of the materials is in solid solution with the matrix material. In addition, the temperature detection material is easy to handle by using the matrix material in a solid state at the use temperature.

As the matrix material satisfying the above conditions, a material in which the energy δ d due to intermolecular dipole interaction and the energy δ h due to intermolecular hydrogen bonding predicted from hansen solubility parameters are 3 or less, respectively, can be preferably used. Specifically, a material having no polar group, preferably a material composed of only hydrocarbon may be used. Specific examples thereof include waxes such as paraffin waxes, microcrystalline waxes, olefin waxes, polypropylene waxes, and polyethylene waxes, low molecular weight materials or high molecular weight materials having a large number of skeletons such as propylene, ethylene, styrene, cycloolefin, siloxane, and terpene, and copolymers thereof.

Among them, a melt having a low viscosity at a melting point or higher and a material which is easily solidified at a melting point or lower have good workability. In addition, the material dissolved in the organic solvent and solidified in the process of volatilization of the organic solvent is also excellent in handling property. Specific examples thereof include paraffin wax, microcrystalline wax, polyolefin, and terpene resins.

Examples of the polyolefin include low molecular weight polyethylene and low molecular weight polypropylene. The molecular weight of the polyolefin and the viscosity in a liquid state are not particularly limited, and when the viscosity in a liquid state is low, the inclusion of bubbles is small and the moldability is good. Specifically, the molecular weight is preferably 5 ten thousand or less and the viscosity near the melting point is 10Pa · S or less, and more preferably 1 ten thousand or less and the viscosity near the melting point is 1Pa · S or less.

In addition, a plurality of these matrix materials may be used in combination.

In addition, even a matrix material that is in a liquid state at the use temperature can be used as the temperature detection material as long as it has a phase separation structure from the temperature indicating material. If the matrix material is a high-viscosity liquid, the handling properties are excellent, as in the case of a solid matrix material. However, in the case where the matrix material is a high-viscosity liquid, precipitation of the temperature indicating material in the matrix material is inevitable in long-term use, and the temperature indicating material eventually separates into 2 phases. Therefore, the long-term stability as a temperature detection material is low.

< phase separation Structure >

FIG. 6 is a schematic diagram showing a phase separation structure of the temperature detection material, in which (a) is a colored state and (b) is a decolored state. The temperature detection material 1 is formed as a phase separation structure in which the temperature indicating material 2 is dispersed in the matrix material 3. That is, the phase containing the leuco dye, the color developer, and the decolorizer forms a structure dispersed in the matrix material.

Fig. 7 is an optical micrograph of the temperature detection material, in which (a) shows a colored state and (b) shows a decolored state. That is, fig. 7(a) is an electron micrograph of the temperature detecting material 1 showing a state in which the temperature material is colored, and fig. 7(b) is an electron micrograph of the temperature detecting material 1 showing a state in which the temperature material is decolored. From the electron micrograph, it can be confirmed that: the temperature detection material 1 is formed as a phase separation structure in which the temperature indicating material 2 is dispersed in the matrix material 3.