WO2019177062A1 - Trititanium pentoxide-based material, method for controlling phase transition temperature of trititanium pentoxide-based material, method for heat absorption, method for converting trititanium pentoxide-based material, sensor element, storage battery management system, and method for producing trititanium pentoxide-based material - Google Patents

Abstract

Provided are: a trititanium pentoxide-based material capable of lowering phase transition temperature; a sensor element containing said trititanium pentoxide-based material; a storage battery provided with said sensor element; and a method for producing substitutional trititanium pentoxide. The trititanium pentoxide-based material has a composition in which some Ti atoms in trititanium pentoxide are substituted with substituent atoms comprising at least one selected from the group consisting of Hf, Zr, Si, Sc, and Y.

Description

Tritium pentoxide-based material, control method of phase transition temperature of trititanium pentoxide-based material, endothermic method, conversion method of trititanium pentoxide-based material, sensor element, storage battery management system, and production of trititanium pentoxide-based material Method

The present invention relates to a trititanium pentoxide-based material, a method for controlling the phase transition temperature of the titanium pentoxide-based material, an endothermic method, a method for converting a trititanium pentoxide-based material, a sensor element, a storage battery management system, and a titanium trioxide The present invention relates to a method for manufacturing a system material. In more detail, the control method of the phase transition temperature of the trititanium pentoxide material, the tritium pentoxide material, the endothermic method, the conversion method of the trititanium pentoxide material, and the sensor element including the trititanium pentoxide material The present invention relates to a storage battery management system including this sensor element and a method for manufacturing a trititanium pentoxide material.

Titanium pentoxide (Ti ₃ O ₅ ), which is a kind of oxide containing titanium, absorbs heat by phase transition. That is, β-trititanium pentoxide (β-Ti ₃ O ₅ ) absorbs heat as it undergoes a phase transition to λ-trititanium pentoxide (λ-Ti ₃ O ₅ ) by heating.

For example, in Patent Document 1, heat storage / heat dissipation is performed by utilizing a solid phase-solid phase transition by applying pressure, heat dissipation light, or heat storage light to titanium dioxide heat storage / radiation titanium oxide having a composition of Ti ₃ O _5. It has been proposed to use titanium oxide as a heat storage material.

International Publication No. 2015/050269

An object of the present invention is to provide a trititanium pentoxide-based material that can have a phase transition temperature lower than that of trititanium pentoxide.

Further, the object of the present invention is to control a phase transition temperature of a trititanium pentoxide-based material, an endothermic method for causing the tritium pentoxide-based material to absorb heat, a conversion method of a trititanium pentoxide-based material, a trititanium pentoxide-based material It is providing the manufacturing method of a storage element management system provided with this sensor element, a storage battery management system provided with this sensor element, and a trititanium pentoxide system material.

In the trititanium pentoxide material according to one embodiment of the present invention, a part of Ti of trititanium pentoxide is a substituent atom composed of at least one selected from the group consisting of Hf, Zr, Si, Sc, and Y. Has a substituted composition.

The trititanium pentoxide material according to one embodiment of the present invention has a β phase having a β-type structure and a λ phase having a λ-type structure.

A method for controlling a phase transition temperature of a trititanium pentoxide material according to one embodiment of the present invention includes adjusting a ratio of a β phase and a λ phase in a trititanium pentoxide material having a β phase and a λ phase. Thus, the phase transition temperature at which the β phase in the trititanium pentoxide-based material transitions to the λ phase is controlled to be lower than the phase transition temperature of β-trititanium pentoxide.

The endothermic method according to an aspect of the present invention is the method of applying heat to the trititanium pentoxide material to cause the β phase in the trititanium pentoxide material to undergo a phase transition to the λ phase. Let the material absorb heat.

In the method for converting a trititanium pentoxide material according to one aspect of the present invention, an external field is applied to a product generated by the phase transition in the trititanium pentoxide material to the λ phase. The λ phase in the product is changed to the β phase.

A sensor element according to an aspect of the present invention includes the trititanium pentoxide material.

The storage battery management system according to an aspect of the present invention includes the sensor element to which heat generated by the storage battery is transmitted, and a processing unit that performs management processing based on the output of the sensor element.

The method for producing a trititanium pentoxide material according to one embodiment of the present invention includes mixing titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y. The resulting mixture is heated by placing it in a hot hydrogen atmosphere.

The method for producing a trititanium pentoxide material according to one embodiment of the present invention includes mixing titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y. The resulting mixture is exposed to an arc discharge under an inert gas atmosphere.

FIG. 1A is a graph showing an example of thermal behavior in accordance with a change in temperature of substituted trititanium pentoxide when substituted with Hf in the first embodiment. FIG. 1B is a graph showing an example of thermal behavior in accordance with a temperature change of substituted trititanium pentoxide when substituted with Hf in the second embodiment. FIG. 2 is a diagram showing an example of a pattern analysis result by X-ray diffraction before and after pressurization of substituted trititanium pentoxide substituted with Hf in the second embodiment. FIG. 3A is a graph showing thermal behavior when the amount of λ phase relative to β phase and λ phase of the mixed type trititanium pentoxide in Example 1 is 0.13. FIG. 3B is a graph showing the thermal behavior when the amount of λ phase relative to β phase and λ phase of mixed type trititanium pentoxide in Example 7 is 0.87. FIG. 4 is a diagram showing a part of a pattern obtained by X-ray diffraction of the mixed type trititanium pentoxide in Examples 1 to 7. FIG. 5 is a comparative diagram comparing X-ray diffraction patterns before and after applying pressure to the mixed trititanium pentoxide in Example 1. FIG. 6 is a block diagram illustrating an outline of a storage battery management system according to an aspect of the present invention. FIG. 7 is a block diagram illustrating an outline of an example of a storage battery management system according to an aspect of the present invention. FIG. 8A is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with Hf atoms in Examples. FIG. 8B is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with Zr atoms in Examples. FIG. 8C is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with Si atoms in Examples. FIG. 8D is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with Sc atoms in Examples. FIG. 8E is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with a Y atom in Examples. FIG. 9A is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with two kinds of substituent atoms (Hf atom and Zr atom) in Examples. FIG. 9B is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with two kinds of substituent atoms (Hf atom and Si atom) in Examples. FIG. 9C is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β1-type phase substituted with two kinds of substituent atoms (Sc atom and Y atom) in Examples. FIG. 10A is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with Hf atoms in Examples. FIG. 10B is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with Zr atoms in Examples. FIG. 10C is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with Si atoms in Examples. FIG. 10D is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with Sc atoms in Examples. FIG. 10E is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with Y atoms in Examples. FIG. 10F is a diagram showing an X-ray diffraction pattern of trititanium pentoxide containing a β2-type phase having no substituent atom. FIG. 11A is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with two kinds of substituent atoms (Hf atom and Zr atom) in Examples. FIG. 11B is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with two kinds of substituent atoms (Hf atom and Si atom) in Examples. FIG. 11C is a diagram showing an X-ray diffraction curve of a substituted trititanium pentoxide containing a β2-type phase substituted with two kinds of substituent atoms (Sc atom and Y atom) in Examples.

Titanium pentoxide has a β-type structure, β-trititanium pentoxide having a β-type structure, λ-trititanium pentoxide having a λ-type structure, and α-tri-pentoxide having an α-type structure. It is classified as titanium. Of these, β-trititanium pentoxide undergoes a phase transition to λ-trititanium pentoxide by heating or the like. Using this β-trititanium pentoxide phase transition, temperature detection or the like is possible. However, for example, β-trititanium pentoxide contained in titanium dioxide with stored and dissipated heat in Patent Document 1 has a phase transition temperature of about 190 ° C., which is a relatively high temperature as a material to be operated by heating or heat generation. . If the phase transition temperature of trititanium pentoxide can be made lower than that of β-titanium pentoxide, the applications of the trititanium pentoxide material can be expanded.

Thus, as a result of intensive studies, the present inventors have come up with a trititanium pentoxide material having a lower phase transition temperature than β-trititanium pentoxide.

The first form of the titanium trioxide pentoxide material of the present embodiment is substitutional type titanium trioxide. Substituted titanium trioxide refers to titanium trioxide in which Ti atoms in Ti ₃ O ₅ are substituted with atoms other than Ti. In the following description, the trititanium pentoxide, an oxide of titanium having a composition of Ti ₃ O _5, unsubstituted of Ti atoms in the Ti ₃ O ₅ is not substituted with atoms other than Ti This represents trititan pentoxide. An unsubstituted type trititanium pentoxide is simply referred to as “titanium pentoxide” and is distinguished from “substituted type trititanium pentoxide”.

The second form of the trititanium pentoxide material of the present embodiment is mixed type trititanium pentoxide. The mixed type trititanium pentoxide refers to trititanium pentoxide having a β phase having a β-type structure and a λ phase having a λ-type structure, as will be described later. Note that the mixed type trititanium pentoxide may be included in the above-described unsubstituted trititanium pentoxide because it does not have to have a substituent atom. However, mixed type titanium trioxide is a novel material having a low phase transition temperature.

The titanium trioxide pentoxide material of the present embodiment includes at least one of a substitution type titanium trioxide and a mixed type titanium trioxide.

First, the substitution type trititanium pentoxide of the first form of the trititanium pentoxide material of the present embodiment will be specifically described.

[Substitutional type titanium trioxide]
The substitution type titanium trioxide replaces a part of Ti of titanium trioxide pentoxide (Ti ₃ O ₅ ) with at least one substitution atom selected from the group consisting of Hf, Zr, Si, Sc, and Y. Having a composition. As described above, the types of crystal structure of trititanium pentoxide include β-trititanium pentoxide having a β-type crystal structure, λ-trititanium pentoxide having a λ-type crystal structure, and α-type crystal structure. There are α-trititanium pentoxide and the like. β-trititanium pentoxide undergoes a phase transition to λ-trititanium pentoxide when heated. On the other hand, substitutional type titanium trioxide may have a β-trititanium pentoxide type crystal structure. Hereinafter, the phase having a β-trititanium pentoxide type crystal structure in the substituted type titanium trioxide is also referred to as a β-type phase. The substituted type trititanium pentoxide may have a β-type crystal structure, specifically, a structure in which a part of Ti of β-trititanium pentoxide is substituted with a substitution atom. The β-type phase is a nonmagnetic semiconductor. When the β-type phase is heated, it undergoes phase transition while endothermic. That is, the substituted trititanium pentoxide having a β-type phase has a phase transition temperature. The phase transition temperature from the β-type phase to the λ-type phase is lower than the phase transition temperature when the β-trititanium pentoxide type transitions to λ-trititanium pentoxide.

Therefore, the substitutional type trititanium pentoxide, which is the first form of the trititanium pentoxide material of the present embodiment, has a phase transition temperature lower than that of trititanium pentoxide.

Substituted titanium trioxide has a lower phase transition temperature than titanium trioxide. When the Ti site of titanium trioxide is replaced with a trivalent or tetravalent element, the crystal structure tends to be distorted. It is presumed that the energy required for the phase transition can be kept low by becoming closer to the α-phase crystal structure of the high-temperature phase with high symmetry. As a result of intensive studies, the inventors have in particular the substitution type 5 of the present invention having a composition substituted with at least one substituent selected from the group consisting of Hf, Zr, Si, Sc, and Y. I came up with trititanium oxide.

The β-type phase is heated to cause a phase transition to a phase having a λ-trititanium pentoxide crystal structure (λ-type phase) and a phase having an α-trititanium pentoxide crystal structure ( (α-type phase). In other words, substitutional titanium trioxide has a phase transition temperature at which the β-type phase transitions to the λ-type phase and a phase transition temperature at which the β-type phase transitions to the α-type phase. . The substitutional type trititanium pentoxide can have any phase transition temperature lower than that of trititanium pentoxide. The crystal structure of the λ-type phase specifically has a structure in which a part of Ti in λ-trititanium pentoxide is substituted with a substituent atom. Specifically, the α-type crystal structure has a structure in which a part of Ti of α-trititanium pentoxide is substituted with a substituent atom. Both the λ-type phase and the α-type phase are paramagnetic conductors. In the present specification, for convenience of explanation, the β-type phase when the β-type phase transitions to the λ-type phase is the β1-type phase, and the β-type phase has a phase transition temperature at which the β-type phase transitions to the α-type phase. The β type phase is called β2 type phase.

The inventors have found production conditions for substituted trititanium pentoxide for having a β1 type phase and production conditions for substituted trititanium pentoxide for having a β2 type phase. Specific manufacturing conditions will be described later.

As described above, the substitutional type trititanium pentoxide is made of at least one selected from the group consisting of Hf, Zr, Si, Sc, and Y as a part of Ti of trititanium pentoxide (Ti ₃ O ₅ ). It has a composition substituted with substituent atoms. For this reason, substitutional titanium trioxide has a lower phase transition temperature than β-trititanium pentoxide.

Substitutional type trititanium pentoxide has a characteristic of absorbing heat when it undergoes phase transition when heated. The endothermic amount of the substitutional type trititanium pentoxide can be adjusted by adjusting the type and ratio of the substituted atoms.

In addition, the crystal structure of substitutional type titanium trioxide can be confirmed by, for example, an X-ray diffraction method (XRD (X-ray Diffraction)). The thermal characteristics such as the phase transition temperature and the endothermic amount of the substitution type trititanium pentoxide can be confirmed by, for example, differential scanning calorimetry (DSC (Differential Scanning calorimetry)).

Substituted trititanium pentoxide undergoes discontinuous changes in physical properties as the crystal structure changes during phase transition. The physical properties that change with the phase transition of the substitutional type titanium trioxide are electrical conductivity, color, magnetism (magnetic susceptibility), thermal conductivity, specific gravity (volume), and the like. By utilizing this change in physical properties, substitution type titanium trioxide can be applied to the sensor element. That is, for example, when substitution-type trititanium pentoxide is detected, if the temperature of the detection target exceeds the phase transition temperature, it is caused by a discontinuous change in physical properties of substitution-type trititanium pentoxide accompanying this phase transition or this change. The present invention can be applied to a sensor element for temperature detection that outputs a phenomenon. The sensor element will be described in detail later.

The amount of substitution atoms relative to the total amount of Ti atoms and substitution atoms in substitution type trititanium pentoxide is preferably 1 at% or more. In this case, the substituted trititanium pentoxide can have a lower phase transition temperature. In the present specification, “at%” is “atom% (atomic%)” and indicates the atomic composition percentage. For example, the amount of substitution atoms in substituted trititanium pentoxide of 1 at% or more is included when the total number of substitution atoms substituting Ti atoms and Ti sites in substituted trititanium pentoxide is 100. It means that the number of substituent atoms is 1 or more.

It is preferable that the substitution atom contains at least one of Hf and Sc. Hf and Sc can particularly reduce the phase transition temperature of substituted trititanium pentoxide. It is also preferable that the substituent atom contains only Hf, it is also preferred that only the Sc is contained, and it is also preferred that only the Hf and Sc are contained. The total amount of Hf and Sc with respect to the total amount of Ti and substituent atoms in the substituted trititanium pentoxide is preferably 1 at% or more. That is, it is preferable that the substitution atom contains Hf, and the amount of Hf with respect to the total amount of Ti and the substitution atom is 1 at% or more. It is also preferable that the substitution atom contains Sc, and the amount of Sc with respect to the total amount of Ti and the substitution atom is 1 at% or more. It is also preferred that the substitution atom contains both Hf and Sc, and the total amount of Hf and Sc relative to the total amount of Ti and substitution atoms is 1 at% or more. In this case, the substituted trititanium pentoxide can have a particularly low phase transition temperature.

It is more preferable that the total amount of Hf and Sc relative to the total amount of Ti and substituent atoms in the substituted trititanium pentoxide is 3 at% or more. That is, it is more preferable that the substitution atom contains Hf and the amount of Hf with respect to the total amount of Ti and the substitution atom is 3 at% or more. More preferably, the substitution atom contains Sc, and the amount of Sc relative to the total amount of Ti and substitution atoms is 3 at% or more. It is more preferable that the substitution atom contains both Hf and Sc, and the total amount of Hf and Sc relative to the total amount of Ti and substitution atoms is 3 at% or more. In these cases, it can be achieved that the substituted trititanium pentoxide has a phase transition temperature of 100 ° C. or less. When the phase transition temperature is 100 ° C. or lower, for example, it is possible to cause the substitution type trititanium pentoxide to absorb heat using water heated to about the boiling point.

More preferably, the substituent atom is only Hf, and the amount of Hf relative to Ti and the substituent atom in the substituted trititanium pentoxide is 3 at% or more. It is further preferable that the substituent atom is only Sc and the amount of Sc relative to Ti and the substituent atom in the substituted trititanium pentoxide is 3 at% or more.

The amount of substitution atoms relative to the total amount of Ti and substitution atoms in substitution type trititanium pentoxide is preferably 10 at% or less. In this case, the phase transition temperature of the substituted trititanium pentoxide can be made lower than that of the tritium pentoxide, and the excellent endothermic characteristics of the substituted trititanium pentoxide can be maintained.

Two or more kinds of substituent atoms may be used. That is, the substitutional type trititanium pentoxide may have a composition in which Ti in trititanium pentoxide is substituted with two or more kinds of substitution atoms selected from Hf, Zr, Sc, Y, and Si. Also in this case, the substitutional type trititanium pentoxide can have a lower phase transition temperature than that of trititanium pentoxide and can have excellent endothermic characteristics.

The substituted trititanium pentoxide may have a β-type phase and a λ-type phase. For example, the substitutional type trititanium pentoxide may be a polycrystalline body in which a crystal structure of a β-type phase and a λ-type phase is mixed. Substitutional type titanium pentoxide having a β-type phase and a λ-type phase can be said to be a mixed type substitutional type titanium trioxide. This mixed substitution type titanium trioxide is clearly distinguished from a simple mixture of substitution type titanium trioxide powder containing only the β type phase and substitution type titanium trioxide powder containing only the λ type phase. It has different properties from this simple mixture. The mixed substitution type titanium trioxide is, for example, a sintered body having a β-type phase composed of crystal grains having a β-type structure and a λ-type phase composed of crystal grains having a λ-type structure, or this sintered body. It may be a powder obtained by pulverizing the knot.

A more specific embodiment of the substitutional type titanium trioxide will be described.

(Embodiment 1)
The substitutional type trititanium pentoxide according to Embodiment 1 has a phase transition temperature at which a β-type phase (β1-type phase) transitions to a λ-type phase. That is, the substitutional type titanium trioxide according to the present embodiment has at least one of a β1 type phase and a λ type phase.

When the substitution type trititanium pentoxide is heated, the β1 type phase absorbs heat and undergoes phase transition to the λ type phase. On the other hand, after the β1-type phase transitions to the λ-type phase, the crystal structure of the λ-type phase does not change and the λ-type phase is maintained by simply cooling the substituted trititanium pentoxide (FIG. 1A). reference).

The substitution type trititanium pentoxide according to Embodiment 1 also has external field responsiveness other than thermal responsiveness. The external field responsiveness refers to the property that the physical properties, structure, and the like change according to external stimuli applied from the outside such as light, pressure, or current that can induce phase transition. For example, pressure response (also referred to as pressure characteristics) is included in the external field response. For example, after the β1-type phase heated by substitutional titanium pentoxide has changed to the λ-type phase, the substitutional trititanium pentoxide can be pressurized so that the λ-type phase can change to the β1-type phase. . The β1-type phase generated thereby remains as the β1-type phase even after the pressure is released. The pressure required for phase transition of the λ-type phase to the β1-type phase is, for example, 1 MPa or more and 3 GPa or less, although it depends on the composition of the substitutional type trititanium pentoxide. When the external stimulus is light, the light is preferably pulsed light. The pulsed light is, for example, Nd: YAG laser light.

The fact that the λ-type phase does not undergo phase transition only when the λ-type phase is cooled means that when the substitutional type trititanium pentoxide is heated and exceeds the phase transition temperature, the thermal history of the substitutional type pentoxide after cooling is reduced. It means that it is memorized in Titanium. Therefore, for example, when substitutional type trititanium pentoxide is applied to a sensor element for temperature detection in particular, it is possible to detect that the temperature to be detected exceeds the phase transition temperature using the sensor element, and to set the phase transition temperature. The sensor element can store the thermal history of exceeding.

The substitutional type trititanium pentoxide according to Embodiment 1 is a mixture of, for example, titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y. It can be obtained by heating in a hydrogen atmosphere. As a result, a substituted trititanium pentoxide containing a β1-type phase is obtained.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for producing a substitutional type titanium trioxide according to Embodiment 1 will be described in detail.

First, a component containing titanium oxide and at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y (hereinafter also referred to as a “substituent atom component”) is prepared. The titanium oxide is preferably titanium dioxide. There is no restriction | limiting in the crystal structure of titanium dioxide, Titanium dioxide may be any of a rutile type, an anatase type, and a brookite type. The substitution atom component may be a simple substance or a compound. Examples of substituent atom components are HfO ₂ (hafnium (IV) oxide), HfSiO ₄ (hafnium silicate (IV)), ZrO ₂ (zirconium oxide (IV)), Sc ₂ O ₃ (scandium oxide (III)), Sc (NO ₃ ) ₃ (scandium nitrate), Y ₂ O ₃ (yttrium oxide (III)), YN (yttrium nitride), SiO ₂ (silicon dioxide), and Si ₃ N ₄ (silicon nitride). The amount of titanium dioxide and the substituent atom component is adjusted according to the ratio of the titanium atom to the substituent atom in the substituted trititanium pentoxide.

Next, for example, a titanium dioxide powder and a substitution atom component powder are mixed to prepare a mixture. The mixture is preferably in the form of pellets, for example. The mixture is put in a firing furnace such as an electric furnace and heated in a high-temperature hydrogen gas atmosphere to obtain substitutional type titanium trioxide. More specifically, for example, the mixture is heated in a firing furnace filled with hydrogen gas or a mixed gas of an inert gas and hydrogen gas. The inert gas is, for example, nitrogen gas. The temperature in the baking furnace at the time of heating is, for example, 1200 ° C. or more and 1600 ° C. or less, and the heating time is, for example, 1 hour or more and 24 hours or less. By this production method, substituted trititanium pentoxide having a β1-type phase can be produced. It can be confirmed that the substituted trititanium pentoxide contains a β1-type phase by comparing the X-ray diffraction pattern of the substituted trititanium pentoxide and the X-ray diffraction pattern of the trititanium pentoxide. This substitution type trititanium pentoxide may contain a λ type phase. However, by applying an external stimulus to the substitution type trititanium pentoxide such as a hydraulic press machine, the λ type phase is changed to β1. A phase transition can be made to the mold phase.

In this production method, for example, when the substituent atom is Hf, the amount of the substituted atom relative to the total amount of Ti and the substituted atom in the substituted trititanium pentoxide (hereinafter also referred to as a substitution ratio) is greater than 0 and less than 10 at%. Substitution type trititanium pentoxide is obtained. When the substitution atom is Zr, a substitution type trititanium pentoxide having a substitution ratio greater than 0 and 3 at% or less is obtained. When the substitution atom is Si, a substitution type trititanium pentoxide having a substitution ratio greater than 0 and 3 at% or less is obtained. When the substitution atom is Sc, a substitution type trititanium pentoxide having a substitution ratio of more than 0 and less than 3 at% is obtained. When the substitution atom is Y, a substitution type trititanium pentoxide having a substitution ratio greater than 0 and 3 at% or less is obtained. Further, in this production method, when the substituent atoms are Hf and Zr, a substituted type trititanium pentoxide in which the ratio of each of Hf and Zr with respect to the total amount of Ti and substituent atoms is greater than 0 and 3 at% or less is obtained. . When the substitution atoms are Hf and Si, a substitutional type trititanium pentoxide in which the ratio of each of Hf and Si to the total amount of Ti and substitution atoms is greater than 0 and 3 at% or less is obtained. When the substituent atoms are Sc and Y, a substituted type trititanium pentoxide in which the ratio of each of Sc and Y to the total amount of Ti and substituent atoms is greater than 0 and 1.5 at% or less is obtained. In addition, the setting of a substitution atom, a combination of substitution atoms, and a substitution ratio is not limited to these, and may be appropriately adjusted according to the composition of the target substitution type trititanium pentoxide.

In addition to the above method, the substituted trititanium pentoxide containing a β1-type phase contains at least one atom selected from the group consisting of titanium oxide and Hf, Zr, Si, Sc, and Y. It can be made by exposing a mixture of components to an arc discharge under an inert gas atmosphere. In this case, a substituted trititanium pentoxide containing a β1-type phase and a λ-type phase is obtained. It can be confirmed that the substituted trititanium pentoxide contains a β1-type phase and a λ-type phase by comparing the X-ray diffraction pattern of the substituted trititanium pentoxide and the X-ray diffraction pattern of trititan pentoxide. . In this production method, it is also preferable to further mix titanium metal in a mixture containing titanium oxide and a substituent atom component. When the mixture contains titanium metal, arc discharge described later can be easily generated.

Specifically, for example, first, titanium dioxide, a substituent atom component, and titanium metal are prepared. The titanium dioxide and the substituted atom component may be the same as described above. The amount of metal titanium, titanium dioxide, and substituted atom component can be adjusted according to the ratio of titanium atom to substituted atom in the substituted trititanium pentoxide. For example, a titanium dioxide powder, a substitution atom component powder, and a metal titanium powder are mixed to prepare a mixture. The mixture is preferably in the form of pellets, for example. This mixture is put into, for example, an arc furnace (arc sintering furnace) and melted by exposure to arc discharge in an inert gas atmosphere. The inert gas is, for example, argon gas. Subsequently, by rapidly cooling the mixture exposed to the arc discharge with water cooling or the like, a substituted trititanium pentoxide containing a λ-type phase and a β1-type phase is obtained.

In this production method, for example, when the substitution atom is Hf, substitution type trititanium pentoxide having a substitution ratio of 10 at% or more can be obtained. When the substitution atom is Sc, substitution-type trititanium pentoxide having a substitution ratio of 3 at% or more is obtained. In addition, these substitution atoms and substitution ratios are shown as an example, and are not limited thereto.

(Embodiment 2)
The substitutional type trititanium pentoxide according to Embodiment 2 has a phase transition temperature at which a β-type phase (β2-type phase) transitions to an α-type phase. That is, the substitutional type titanium trioxide according to the present embodiment has at least one of a β2 type phase and an α type phase.

When the substitutional type trititanium pentoxide according to Embodiment 2 is heated, the β2 type phase absorbs heat and undergoes phase transition to the α type phase. In addition, after the β2-type phase transitions to the α-type phase, when the substituted trititanium pentoxide is cooled, the α-type phase dissipates heat and transitions to the β2-type phase. That is, the substitutional type trititanium pentoxide according to the present embodiment has not only the phase transition temperature at which the β2 type phase transitions to the α type phase but also the phase transition temperature at which the α type phase transitions to the β2 type phase ( (See FIG. 1B). For this reason, when the substitution type titanium trioxide according to the present embodiment is applied to a sensor element for temperature detection, a sensor element that can be used repeatedly can be obtained. Moreover, since substitution type | mold trititanium pentoxide which concerns on this embodiment can reversibly phase-change in response to temperature, it has a heat storage / heat dissipation characteristic, Therefore, it can utilize also as a heat storage / heat dissipation material.

In the substitution type trititanium pentoxide according to the present embodiment, a part of Ti of trititanium pentoxide (Ti ₃ O ₅ ) is substituted by at least one selected from the group consisting of Hf, Zr, Sc, and Y. It is preferable to have a composition substituted with atoms. In this case, the substitutional type titanium trioxide has a low phase transition temperature and can have excellent heat absorbing / dissipating characteristics.

A method for producing a substituted titanium trioxide according to Embodiment 2 will be described.

The substitutional type trititanium pentoxide according to the present embodiment is a mixture of titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y. Obtained by exposure to arc discharge in an active gas atmosphere. In this case, a substituted trititanium pentoxide containing a β2-type phase is obtained. It can be confirmed that the substituted trititanium pentoxide contains a β2-type phase by comparing the X-ray diffraction pattern of the substituted trititanium pentoxide with the X-ray diffraction pattern of trititan pentoxide.

In the production of the substitutional type trititanium pentoxide according to the present embodiment, it is also preferable that titanium metal and titanium metal are further blended in the mixture containing the substitutional atom component. When the mixture includes titanium metal, it is possible to easily generate arc discharge due to the improvement in the conductivity of the mixture. For this reason, the production efficiency of substituted titanium pentoxide containing a β2-type phase can be improved. In this case, by appropriately adjusting the blending amount of metal titanium and titanium dioxide, it is easy to obtain a structure of substituted trititanium pentoxide including a β2-type phase having a target composition.

Specifically, the substituted trititanium pentoxide containing the β2-type phase can be produced, for example, as follows.

First, titanium dioxide, a substitution atom component, and titanium metal are prepared. The titanium dioxide and the substituted atom component may be the same as those described in the first embodiment. The amount of titanium metal, titanium dioxide, and substitution atom component can be adjusted according to the ratio of titanium atom to substitution atom in substitution type trititanium pentoxide. Next, for example, titanium dioxide powder, substitution atom component powder, and metal titanium powder are mixed to prepare a mixture. The mixture is preferably in the form of pellets, for example. This mixture is put into, for example, an arc furnace (arc sintering furnace) and melted by exposure to arc discharge in an inert gas atmosphere. The inert gas is, for example, argon gas. Subsequently, the mixture exposed to the arc discharge is rapidly cooled by water cooling or the like, so that a substituted trititanium pentoxide having a β2 type phase is obtained.

In this production method, for example, when the substitution atom is Hf, substitution type titanium trioxide having a substitution ratio of greater than 0 and less than 3 at% is obtained. When the substitution atom is Zr, a substitution type trititanium pentoxide having a substitution ratio greater than 0 and 3 at% or less is obtained. When the substitution atom is Si, a substitution type trititanium pentoxide having a substitution ratio greater than 0 and 3 at% or less is obtained. When the substitution atom is Sc, a substitution type trititanium pentoxide having a substitution ratio of more than 0 and less than 3 at% is obtained. When the substitution atom is Y, a substitution type trititanium pentoxide having a substitution ratio greater than 0 and 3 at% or less is obtained. Further, when the substituent atoms are Hf and Zr, a substituted type trititanium pentoxide in which the ratio of each of Hf and Zr to the total amount of Ti and substituent atoms is greater than 0 and 1.5 at% or less is obtained. When the substituent atoms are Hf and Si, a substituted trititanium pentoxide in which the ratio of each of Hf and Si to the total amount of Ti and substituent atoms is greater than 0 and 1.5 at% or less is obtained. When the substituent atoms are Sc and Y, a substituted type trititanium pentoxide in which the ratio of each of Sc and Y to the total amount of Ti and substituent atoms is greater than 0 and 1.5 at% or less is obtained. The setting of the substitution atom, the combination of substitution atoms, and the substitution ratio is not limited to these, and may be adjusted as appropriate according to the composition of the target substitution type trititanium pentoxide.

(Embodiment 3)
The substitution type trititanium pentoxide according to Embodiment 3 has a phase transition temperature (hereinafter also referred to as T1) at which a β-type phase (β1-type phase) transitions to a λ-type phase, and a β-type phase (β2-type phase). It has a phase transition temperature (hereinafter also referred to as T2) that causes a phase transition to the α-type phase. Since the β2-type phase and the α-type phase reversibly undergo a phase transition in response to heat, the substitutional type trititanium pentoxide according to the present embodiment has the α-type phase as the β-type phase (β2-type phase). It also has a phase transition temperature for transition (hereinafter also referred to as T3). That is, the substitutional type trititanium pentoxide according to the present embodiment has at least one of a β1 type phase and a λ type phase and at least one of a β2 type phase and an α type phase.

For example, a relationship of “T3 <T1 <T2” can be established between the three types of phase transition temperatures in the substitution type trititanium pentoxide according to the third embodiment. In this case, when the substitutional type trititanium pentoxide is heated, first, the β1 type phase is changed to the λ type phase at T1, and when further heated, the β2 type phase is changed to the α type phase at T2. Subsequently, when the substitutional type titanium trioxide is cooled, the α-type phase transitions to the β2 phase at T3, but the λ-type phase is maintained without phase transition. Thus, the presence of the λ-type phase in the substituted trititanium pentoxide after cooling means that when the substituted trititanium pentoxide exceeds the heated T1 and T2 in turn, the thermal history of the substituted trititanium pentoxide even after cooling Means stored in trititan pentoxide. Therefore, for example, when substitutional type trititanium pentoxide is applied to a sensor element for detecting temperature in particular, it is possible to detect that the temperature of the detection target exceeds T1 and T2 using the sensor element, and exceeds T2. In that case, the sensor element can store the thermal history.

Next, the mixed type trititanium pentoxide which is the second form of the titanium trioxide based material of the present embodiment will be specifically described.

The mixed type trititanium pentoxide according to this embodiment has a β phase having a β-type structure and a λ phase having a λ-type structure. When heat is applied to the mixed trititan pentoxide, the β phase in the mixed trititan pentoxide undergoes a phase transition to the λ phase. That is, mixed type titanium trioxide has a phase transition temperature at which the β phase transitions to the λ phase. The phase transition temperature of this mixed type trititanium pentoxide can be lower than the phase transition temperature of β-trititanium pentoxide.

Note that having a β-type structure means having a β-trititanium pentoxide structure, and having a λ-type structure means having a λ-trititanium pentoxide structure.

Mixed type trititanium pentoxide is a polycrystal with a β-phase and λ-phase crystal structure mixed inside, and it is simply composed of β-trititanium pentoxide powder and λ-trititanium pentoxide powder. Different from the mixture. The mixed type trititanium pentoxide is obtained, for example, by sintering a sintered body including a β phase composed of crystal grains having a β-type structure and a λ phase composed of crystal grains having a λ-type structure, or by pulverizing the sintered body. Powder.

The reason why the mixed type trititanium pentoxide may have a low phase transition temperature is not clear, but by having both the β phase and the λ phase in the trititanium pentoxide, This is presumably because β-trititanium pentoxide and λ-trititanium pentoxide having a monoclinic crystal structure have a different axis angle β. The inter-axis angle in the crystal structure is an angle between two axes formed by two axes selected from the a-axis, b-axis, and c-axis in the crystal lattice, and is expressed by inter-axis angles α, β, and γ. Is done. The inter-axis angle α is, for example, an angle between the b-axis and the c-axis, and the inter-axis angle γ is, for example, an angle between the b-axis and the a-axis. In the monoclinic system, the inter-axis angle α is And γ are both 90 degrees. The inter-axis angle β is, for example, an angle between the a-axis and the c-axis, and is an angle different from 90 degrees in the monoclinic system. In the mixed type trititanium pentoxide, the angle β between the axes of the λ phase, which is asymmetric, is closer to 90 degrees compared to the conventional β-trititanium pentoxide. It is thought that a structure with higher symmetry than titanium can be maintained. In other words, the mixed type titanium trioxide has a crystal structure of a high-temperature phase (that is, α-trititanium pentoxide having an orthorhombic crystal structure) with an angle between the axes of 90 degrees and high symmetry. This is probably because the energy required for the phase transition tends to be low due to the close structure. In mixed type titanium trioxide, the larger the ratio of the λ phase, the larger the effect described above, and the lower the phase transition temperature.

Whether the mixed type trititanium pentoxide has a β phase and a λ phase can be determined by analyzing the crystal structure of the mixed type trititanium pentoxide by, for example, an X-ray diffraction method (XRD (X-ray Diffraction)). More specifically, it can be confirmed by determining the peak position using the crystal structure data file of λ phase and β phase based on the diffraction pattern of mixed type trititanium pentoxide obtained by X-ray diffraction method. .

The inter-axis angle β of the crystal lattice of the λ phase in the mixed type trititanium pentoxide is preferably less than 91.29 degrees. In this case, the mixed type trititanium pentoxide can have a lower phase transition temperature. The inter-axis angle β of the crystal lattice of the λ phase is more preferably 91.12 degrees or less. The interaxial angle of the crystal lattice can be confirmed by calculating the lattice constant by Rietveld analysis from the obtained diffraction pattern by, for example, the X-ray diffraction method.

The phase transition temperature of the mixed type titanium trioxide may be less than 190 ° C. For this reason, mixed type trititanium pentoxide can be utilized as an endothermic material capable of absorbing heat at a lower temperature than conventional trititanium pentoxide. The mixed type trititanium pentoxide can have a phase transition temperature of 120 ° C. or higher and 160 ° C. or lower, for example. The phase transition temperature may be less than 120 ° C. The phase transition temperature and the endothermic amount at the time of the phase transition can be determined from, for example, an endothermic peak measured by a differential scanning calorimetry (DSC (Differential Scanning calorimetry)) apparatus.

The mixed type trititanium pentoxide preferably has a phase transition temperature lower than that of β-titanium pentoxide.

The control of the phase transition temperature of the mixed type trititanium pentoxide of this embodiment can be realized by adjusting the ratio of the β phase and the λ phase. That is, the control method of the phase transition temperature of the mixed type trititanium pentoxide according to the present embodiment adjusts the ratio of the β phase to the λ phase in the mixed type trititanium pentoxide, thereby The phase transition temperature at which the β phase in the phase transitions to the λ phase is controlled to be lower than the phase transition temperature of β-trititanium pentoxide. Factors other than the ratio of β phase to λ phase also affect the phase transition temperature, but in general, the larger the proportion of λ phase in the mixed type trititanium pentoxide, the more the phase transition temperature of the mixed type trititanium pentoxide. Can be lowered. Therefore, by adjusting the ratio of the β phase and the λ phase, the phase transition temperature of the mixed type trititanium pentoxide can be set to the target temperature or close to the target temperature.

Adjustment of the ratio of β-phase and λ-phase of mixed type trititanium pentoxide, for example, conditions such as temperature, atmosphere, heating and firing time, and particle size of raw titanium dioxide when synthesizing mixed type trititanium pentoxide Can be carried out by appropriately adjusting.

Mixed type titanium trioxide is obtained, for example, as follows.

Mixed type titanium trioxide can be produced by heating and firing titanium dioxide in a reducing atmosphere using a firing furnace such as an electric furnace. Specifically, the mixed type titanium trioxide is obtained, for example, by sequentially performing five steps from the first step to the fifth step.

First, in the first step, titanium dioxide is prepared. Titanium dioxide may be any of rutile, anatase, and brookite, and may include two or more of these. Titanium dioxide is put into a firing furnace, and the inside of the firing furnace is heated to the first heating temperature in an inert gas atmosphere such as a nitrogen atmosphere. As for the heating conditions, for example, the temperature raising rate can be 0.5 ° C./min to 3.5 ° C./min, and the first heating temperature can be 100 ° C. to 300 ° C.

Subsequently, in the second step, the inside of the firing furnace is maintained at the first heating temperature reached in the first step while the inside of the firing furnace is maintained in an inert gas atmosphere such as a nitrogen atmosphere. The 1st maintenance time to maintain can be 5 minutes or more and 1 hour or less, for example.

Subsequently, in the third step, the atmosphere in the firing furnace is changed to a reducing atmosphere, for example, a mixed gas atmosphere of nitrogen and hydrogen, and the temperature in the firing furnace is raised to the second heating temperature. The atmosphere may be changed by any method at any time in the second step. For example, a reducing gas such as hydrogen gas may be supplied into the firing furnace before the start of temperature increase, or may be supplied when the inside of the firing furnace reaches the second heating temperature, You may supply in warm. When the reducing atmosphere is a mixed gas atmosphere of nitrogen and hydrogen, the ratio of hydrogen in the mixed gas atmosphere can be set to 1% or more and 10% or less, for example. As for the heating conditions in the third step, for example, the rate of temperature rise may be, for example, 0.5 ° C./min to 3.5 ° C./min, and the second heating temperature may be 1200 ° C. to 1600 ° C.

Subsequently, in the fourth step, the temperature in the firing furnace is maintained at the second heating temperature while maintaining the reducing furnace in the reducing atmosphere achieved in the third step. The 2nd maintenance time to maintain can be made into 1 hour or more and 24 hours or less, for example.

Subsequently, in the fifth step, the temperature in the firing furnace is lowered. Thereby, the temperature in a baking furnace is made into room temperature, for example. In this case, the temperature drop rate is, for example, not less than 0.5 ° C./min and not more than 3.5 ° C./min. In the fifth step, the atmosphere in the firing furnace may be changed to an inert gas atmosphere such as a nitrogen gas atmosphere at any time.

The heating conditions such as the heating rate, the heating temperature, and the heating time in the above steps, and the gas composition in the gas atmosphere can be adjusted as appropriate. Moreover, each said step may be abbreviate | omitted according to a condition suitably, and may include steps other than these.

As described above, the mixed type trititanium pentoxide according to the present embodiment appropriately adjusts the heating conditions such as the heating temperature and the heating time during firing, and the reducing atmosphere conditions such as the hydrogen ratio, so that the desired β phase and λ Phase. For example, the rate of temperature increase in the third step is 1 ° C./min to 3 ° C./min, the second heating temperature is 1350 ° C. to 1500 ° C., and the firing time in the fourth step is 3 hours to 12 hours. When the time is less than or equal to the time, mixed-type trititanium pentoxide having a mass ratio of the β phase to the λ phase in the range of 87:13 to 13:87 is obtained. The second heating temperature in the third step is more preferably higher than the heating temperature of about 1200 ° C. in the case of producing conventional β-titanium pentoxide. Further, for example, the ratio of the λ phase can be increased by increasing the firing time condition in the fourth step, and the β phase ratio can be increased by shortening the firing time condition in the fourth step. be able to.

The mass ratio between the β phase and the λ phase can be calculated by a reference intensity ratio (RIR) method. For example, in the X-ray diffraction pattern of the mixed type trititanium pentoxide, the strongest line of the test component The reference intensity ratio (RIR value) described in the database is calculated from the integrated intensity at.

Mixed type trititanium pentoxide can cause the β phase in the mixed type trititanium pentoxide to undergo phase transition to λ phase by absorbing heat generated by heating or the like. That is, the endothermic method according to the present embodiment provides heat to the mixed type trititanium pentoxide by applying heat to the mixed type trititanium pentoxide and causing the β phase in the mixed type trititanium pentoxide to transition to the λ phase. Let According to this endothermic method, even when the temperature is lower than that of β-titanium pentoxide, the mixed type trititanium pentoxide can absorb the ambient heat.

The mixed tritium pentoxide conversion method according to the present embodiment provides a product obtained by applying an external field to a product produced by the phase transition of the mixed trititanium pentoxide to the λ phase. The λ phase in the phase is changed to the β phase. The external field is an external stimulus that can induce a phase transition of the β phase to the λ phase in the mixed type trititanium pentoxide, such as light, pressure, and current. Note that the λ phase in the product does not transition to the β phase simply by cooling.

For example, by heating mixed titanium trioxide pentoxide, the β phase in the mixed titanium trioxide transitions to the λ phase to form λ-trititanium pentoxide, and then λ-trititanium pentoxide. In addition, by applying at least one external field selected from the group consisting of light, pressure, and current, λ-trititanium pentoxide can be converted to β-trititanium pentoxide. In other words, the mixed type trititanium pentoxide has external field responsiveness other than thermal responsiveness. The external field responsiveness refers to the property that the physical properties, structure, and the like change according to the external field, and examples thereof include pressure responsiveness (also referred to as pressure characteristics). For example, when the mixed trititanium pentoxide is heated and the product obtained by the β phase transition to the λ phase is pressurized, the λ phase in the product can transition to the β phase. . The β phase generated thereby is maintained in the β phase even after the pressure is released. The pressure required for phase transition from the λ phase to the β phase is, for example, 100 MPa or more and 3 GPa or less. When the external field is light, the light is preferably pulsed light. The pulsed light is, for example, Nd: YAG laser light.

The fact that the phase transition to the β phase is not achieved simply by cooling the λ phase means that when the mixed type trititanium pentoxide is heated and exceeds the phase transition temperature, its thermal history will remain even after cooling. It means that it is memorized. For this reason, for example, when mixed type titanium trioxide is applied to a sensor element for temperature detection, it is possible to detect that the temperature to be detected exceeds the phase transition temperature using the sensor element, and the phase transition temperature. The sensor element can memorize the thermal history of exceeding. Furthermore, mixed-type trititanium pentoxide can absorb heat when it undergoes a phase transition from a β phase to a λ phase, and thus can be used as an endothermic material.

In addition, since the mixed type titanium trioxide has a λ phase, even before heating, the λ phase can be obtained by applying at least one external field selected from the group consisting of light, pressure, and current. It can be transferred to the β phase. This also makes it possible to convert the mixed type trititanium pentoxide to β-trititanium pentoxide.

Next, a sensor element provided with the trititanium pentoxide material of the present embodiment described above will be described. In addition, the use of the trititanium pentoxide material of the present embodiment is not limited to the sensor element, and can be applied to uses such as a heat insulating material and a heat storage material.

[Sensor element]
As already explained, the trititanium pentoxide material can be applied to the sensor element.

The trititanium pentoxide material can be applied to a sensor element for temperature detection, for example. In this case, for example, when the temperature of the trititanium pentoxide material exceeds the phase transition temperature, a discontinuous change in the physical properties of the trititanium pentoxide material accompanying the phase transition or a phenomenon caused by this change is output. To do.

Also, as already described, the trititanium pentoxide-based material can also undergo a phase transition in response to an external field other than temperature, such as light, pressure, or current. For this reason, the trititanium pentoxide material can also be applied to a sensor element for detecting an appropriate external field.

The output of the sensor element includes electrical conductivity (electrical conductivity), color, magnetism (magnetic susceptibility), volume change (specific gravity change), or thermal conductivity (thermal conductivity) that changes with phase transition. Etc.

Regarding electrical conductivity, in the trititanium pentoxide-based material, the β-phase and β-type phase are semiconductors, and the λ-phase, λ-type phase, α-phase, and α-type phase are conductors. Therefore, the sensor element can output a change in electrical conductivity. Note that the sensor element has an electrical conductivity such as a change in voltage due to a change in electrical conductivity when a constant current is passed, and a change in current due to a change in electrical conductivity when a constant voltage is applied. You may output the phenomenon which arises with a change of.

Regarding the color, β-trititanium pentoxide is red or reddish brown, and λ-trititanium pentoxide is black blue or blue. The β-type phase is red or reddish brown, the λ-type phase is black-blue or blue, and the α-type phase is black. For this reason, the sensor element can output a color change due to the phase transition of the trititanium pentoxide material.

Regarding magnetic properties, β-trititanium pentoxide is non-magnetic, and λ-trititanium pentoxide is paramagnetic. The β-type phase is nonmagnetic, and the λ-type phase and the α-type phase are paramagnetic. Therefore, the sensor element can output a change in magnetism due to the phase transition of the trititanium pentoxide material.

Also, regarding the volume, since a volume change may occur during the phase transition of the trititanium pentoxide material, a change in physical properties based on the volume change or specific gravity change may be output.

Note that the output of the sensor element is not limited to the above.

The sensor element includes a molded body containing, for example, a trititanium pentoxide material. The molded body only needs to contain at least one of the substitution type trititanium pentoxide and the mixed type trititanium pentoxide, and the molded body does not hinder the purpose of use of the sensor element. If necessary, components other than the trititanium pentoxide material may be contained. Examples of the component other than the trititanium pentoxide material include a resin component that functions as a binder. Therefore, a molded object may be produced from the composition prepared by mix | blending a trititanium pentoxide type material with a resin component etc.

The molded body can have an appropriate shape. For example, substitution type titanium trioxide can be molded with a molding machine to obtain a cylindrical shaped body, but the present invention is not limited to this. What is necessary is just to adjust the dimension of a sensor element suitably according to a use etc.

The sensor element may include an electrode that is electrically connected to the molded body. The sensor element includes, for example, two electrodes, and the electrode and the molded body are laminated so that the molded body is interposed between the two electrodes. When the sensor element includes an electrode, the sensor element can emit an output through the electrode. The sensor element itself does not include an electrode, and the electrode may be electrically connected to the sensor element when an output is obtained from the sensor element.

The electrode is made of, for example, a metal, a conductive oxide, a carbon material, or a conductive polymer. Examples of the metal include Al, Ag, Au, Cu, and Pt. Examples of the conductive oxide include indium tin oxide (ITO: Indium Tin Oxide). Examples of the carbon material include graphite. Examples of the conductive polymer include polythiophene polymers, polyaniline polymers, and polyacetylene polymers.

The device that detects the output of the sensor element is, for example, a device that detects a change in electrical resistance value, but is not limited thereto. For example, a spectrum measurement device configured to detect a color change, a magnetic change is detected. It may be a magnetometer or a specific gravity measuring device that measures a change in specific gravity.

As described above, the sensor element according to the present embodiment can be used as a sensor for various applications that can respond to surrounding external stimuli.

[Storage battery management system]
An outline of the storage battery management system according to the present embodiment will be described.

As shown in FIG. 6, the storage battery management system 1 according to this embodiment includes the sensor element 3 and a processing unit 4 that performs a management process based on the output of the sensor element 3.

The storage battery management system 1 is a system for managing a storage battery 2 (also referred to as a cell) that receives external power and charges and discharges based on the power. The storage battery management system 1 performs an appropriate management process in the processing unit 4 when the sensor element 3 detects a heat generation state exceeding the temperature during normal use of the storage battery 2 during charging / discharging of the storage battery 2.

The storage battery management system 1 can manage a plurality of storage batteries 2. In the storage battery management system 1, the storage battery 2 is a target of temperature detection for the sensor element 3 to detect the temperature. Moreover, in the storage battery management system 1, the state in which the storage battery 2 exceeded predetermined temperature is made into the object of management processing.

The storage battery management system 1 is electrically connected between an electrical load 7 such as an electrical device (including electronic devices) and the plurality of storage batteries 2, for example, so that power is supplied from the plurality of storage batteries to the electrical load 7. Control. In addition, the storage battery management system 1 controls charging of the plurality of storage batteries 2 by being electrically connected between the external power source 6 and the plurality of storage batteries 2.

The storage battery management system 1 may include a battery block 21 having a block including a plurality of storage batteries 2 (also referred to as a cell group 20) and the sensor element 3 as a unit, and the processing unit 4. In the case of the battery block 21, for example, a plurality of battery blocks 21 may be connected in parallel so that they can be electrically connected to the terminals. What is necessary is just to adjust the number of the battery blocks 21 suitably according to the use of the storage battery in the storage battery management system 1. FIG. The battery block 21 can have, for example, the cell group 20, the protection circuit board, the sensor element 3, and the recovery mechanism. The protection circuit board includes a board and an electronic circuit mounted on the surface of the board. The cell group 20 includes a plurality of storage batteries 2 connected in series. The cell group 20 is included in the battery block 21. What is necessary is just to set the number of the storage batteries 2 suitably according to the performance of the storage battery 2, and the use of the storage battery management system 1. FIG. Examples of the storage battery 2 include a lithium ion battery, a nickel hydrogen battery, a nickel cadmium battery, and a lead battery. The shape or size of the storage battery 2 is not particularly limited as long as the storage battery 2 can be thermally connected to the sensor element 3, and can be appropriately adjusted according to the usage of the storage battery management system 1.

The sensor element 3 is thermally connected to the storage battery 2. Therefore, the heat generated in the storage battery 2 can be transmitted to the sensor element 3. As described above, the sensor element 3 includes the substitutional type trititanium pentoxide. Therefore, when the temperature of the trititanium pentoxide material exceeds the phase transition temperature, the physical properties of the substitutional type trititanium pentoxide associated with the phase transition. A change or a phenomenon caused by this change is output.

The processing unit 4 has a function of performing management processing based on the output of the sensor element 3. Based on the output of the sensor element 3 includes not only a direct output from the sensor element itself but also an indirect output. The indirect output is, for example, another function through each functional unit having a predetermined function such as a physical property detection unit for detecting a physical property, a conversion unit that converts an output from the physical property detection unit into a predetermined output signal, and the like. Contains the output converted to a signal. Therefore, the processing unit 4 may be directly connected to the sensor element 3 or may be indirectly connected. Examples of the management process include, but are not limited to, such as suppression of charging / discharging of the storage battery 2, determination of the state of the storage battery 2, notification of abnormality of the storage battery 2, switching of an abnormal circuit of the storage battery 2, and the like.

The processing unit 4 performs various management processes via a computer having at least a processor and a memory, for example. Each function is realized by the processor executing a program stored in the memory. This program may be provided through a telecommunication line such as the Internet, or may be provided by a computer-readable non-transitory recording medium. Therefore, the processing unit 4 can execute management processing corresponding to the output based on the output of the sensor element 3 according to, for example, a program stored in the memory. Therefore, for example, when it is determined that the heat generation of the storage battery 2 is abnormal, charging / discharging of the storage battery 2 is controlled by controlling a power feeding path of a circuit connecting the storage battery 2 and the external power source 6. Further, the processing unit 4 can notify the abnormality by transmitting the abnormality information to an external terminal or the like via the communication unit.

A specific example of the storage battery management system 1 will be described with reference to FIG.

The storage battery management system 1 shown in FIG. 7 is a system configured to control at least one of power supply (charging) to the storage battery 2 and power supply (discharge) from the storage battery 2. The storage battery management system 1 includes a sensor element 3 to which heat from the storage battery 2 is transmitted, and a processing unit 4 that performs management processing based on the output of the sensor element 3. The storage battery management system 1 further includes an electrical resistance detection unit 31 and a control unit 32. The electrical resistance detector 31 detects a change in electrical resistance value due to the phase transition of the trititanium pentoxide material of the sensor element 3. The control unit 32 transmits a control signal to the processing unit 4 so as to control at least one of charging of the storage battery 2 and discharging of the storage battery 2 based on the electrical resistance value detected by the electrical resistance detection unit 31. Thereby, the storage battery management system 1 determines whether or not an abnormality has occurred due to heat generation of the storage battery 2 and suppresses at least one of charging of the storage battery 2 and discharging of the storage battery 2 when an abnormality occurs. it can. Furthermore, in the storage battery management system 1, even if an abnormality due to heat generation of the storage battery 2 occurs and the temperature around the storage battery 2 rises, heat can be absorbed at the phase transition temperature of the substitutional trititanium pentoxide in the sensor element 3. It is possible to suppress an excessive increase in the temperature around 2.

Since the sensor element 3 is a sensor element provided with a trititanium pentoxide material, the electrical resistance value can be changed with the phase transition of the trititanium pentoxide material. As the configuration of the sensor element 3, the already described one can be adopted as appropriate.

The electrical resistance detector 31 is configured to detect the sensor element 3 based on the change in electrical conductivity of the trititanium pentoxide material when the titanium pentoxide material in the sensor element 3 undergoes a phase transition based on a temperature change due to heat generation of the storage battery 2. Detect changes in electrical resistance.

The electrical resistance detection unit 31 measures the electrical resistance value of the sensor element 3 by measuring the voltage across the sensor element 3 with a constant current flowing through the sensor element 3, for example. In this case, the change in the electrical resistance value of the sensor element 3 due to the phase transition when the trititanium pentoxide-based material in the thermally connected sensor element 3 undergoes a phase transition due to heat generation from the storage battery 2 is detected by electrical resistance. This is detected by the unit 31. The processing unit 4 can determine that an abnormality such as heat generation has occurred in the storage battery 2 by detecting that the detected change amount of the electrical resistance value exceeds the threshold value. Then, the processing unit 4 transmits, to the processing unit 4, a control signal for controlling at least one of charging of the storage battery 2 and discharging of the storage battery 2 by the control unit 32 based on the signal that has detected the electrical resistance value after the transition. Then, management processing is performed according to the control signal received by the processing unit 4.

The electrical resistance detector 31 is configured to always detect and measure the electrical resistance value. In this case, the electrical resistance value that is constantly detected and measured changes at the timing before and after the phase transition of the trititanium pentoxide material in the sensor element 3. When the electrical resistance value that is constantly detected and measured exceeds a threshold that is determined in advance based on the difference between the electrical resistance values before and after the phase transition, it can be determined that an abnormality such as heat generation has occurred in the storage battery 2. . And the storage battery management system 1 can perform the management process which controls at least one of charge of the storage battery 2 and discharge of the storage battery 2 by the process part 4 based on the signal output from the electrical resistance detection part 31. FIG. .

The electric resistance detection unit 31 in FIG. 6 detects a change in the electric resistance value associated with the phase transition of the trititanium pentoxide material in the sensor element 3, but accompanies the phase transition of the substitutional type titanium trioxide. What is necessary is just to be comprised so that the change of a physical property can be detected. Therefore, the detection part which detects physical properties other than electrical conductivity may be sufficient. Examples of other detection units include a spectrum measurement device, a specific gravity measurement device, and a magnetic measurement device.

The control unit 32 is configured to transmit a control signal to the switch 81, 82, or 83 when the heat generation state exceeding the temperature during normal use of the storage battery 2 is detected mainly when the storage battery 2 is charged / discharged. . The switch 81, 82 or 83 is realized by a semiconductor switch or a mechanical switch, for example. The switch 81, 82 or 83 is electrically connected between the storage battery 2 and the external power source 6 and between the storage battery 2 and the electric load 7. The switch 81, 82, or 83 is turned on / off according to the control signal, and controls at least one of power supply (charging) to the storage battery 2 and power supply (discharge) from the storage battery 2. The control unit 32 only needs to be able to control at least one of charging of the storage battery 2 and discharging of the storage battery 2 based on the electrical resistance value detected by the electrical resistance detection unit 31.

The control unit 32 is supplied with power from a power source different from that of the storage battery 2, for example. The control unit 32 may include a voltage monitoring unit that monitors the voltage of the storage battery 2. In this case, the control unit 32 may be configured to cut off charging / discharging of the storage battery 2 when the voltage of the storage battery 2 detected by the voltage monitoring unit exceeds a predetermined value.

In addition, since the titanium pentoxide-based material can undergo phase transition in response to an external field other than temperature, the storage battery management system 1 detects heat generation from the storage battery 2 as necessary to detect substitutional pentoxide. When titanium undergoes a phase transition to the λ-type phase, a conversion mechanism may be provided for applying an external field to cause a phase transition to the β-type phase. The conversion mechanism may be, for example, a pressurizing device that applies pressure, or a piezoelectric element that responds by applying a specific voltage. The conversion mechanism and the sensor element 3 may be in direct contact. The conversion mechanism is not limited to these. Further, when the phase transition from the λ-type phase to the β-type phase is performed, the storage battery management system 1 releases the amount of heat absorbed by the substitution type trititanium pentoxide. A heat mechanism or an energy conversion mechanism that converts this amount of heat into other energy may be provided. The conversion mechanism, the exhaust heat mechanism, and the energy conversion mechanism may be configured to be controlled by the control unit 32. These mechanisms are not particularly limited, and can be appropriately provided depending on the intended use and purpose.

In the above description, the storage battery management system 1 has been described with respect to the case where there is one storage battery 2, but it may be a cell group 20 including a plurality of storage batteries 2. In this case, the sensor element 3 and the electrical resistance detection unit 31 can be provided for each storage battery 2. In addition, one sensor element 3 and one electric resistance detector 31 may be provided for each cell group 20. In this case, the electrical resistance detector 31 detects the change in the electrical resistance value of the trititanium pentoxide material when the trititanium pentoxide material in the sensor element 3 undergoes a phase transition based on the temperature change due to the heat generation of the cell group 20. What is necessary is just to be comprised so that it may detect.

In this embodiment, the storage battery is a target for temperature detection, and the state in which the storage battery exceeds a predetermined temperature is a target for management processing, but the present invention is not limited to this. As an example, the processing unit 4 may be a heating element whose temperature detection target generates heat by power feeding, and the management processing target may be related to this temperature detection target. Examples of the heating element that generates heat by power supply include home appliances, lighting equipment, medical equipment, electric furnaces, switchboards, water heaters, anti-fogging equipment, and anti-freezing equipment. For example, in the processing unit 4 that uses a home appliance as a temperature detection target and an alarm as a management processing target, the alarm sounds based on a change in physical properties of the trititanium pentoxide material in the sensor element 3 due to heat generated by the home appliance. It may be configured as follows. Further, in the processing unit 4, the temperature detection target may be a management processing target. As an example, the processing unit 4 that uses a temperature-controllable electric furnace as a temperature detection target and a management process target is based on changes in physical properties of the trititanium pentoxide material in the sensor element 3 due to heat generation in the electric furnace. And may be configured to control the temperature of the electric furnace.

Hereinafter, specific examples of the present invention will be presented. However, the present invention is not limited to the examples.

(1) Synthesis of Substitutional Type Titanium Pentoxide (1-1) Synthesis of Substitutional Type Titanium Pentoxide (β1 Type Phase) Rutile type titanium dioxide powder (average particle size of about 5 μm) and “Substitution Atom” in Table 1 The components containing the atoms shown in the column of were mixed so as to have the “substitution ratio” shown in Table 1 to prepare a mixture. This mixture is put into a firing furnace (Taman tube furnace), set to a gas flow rate of 1.0 L / min or less, and switched to a mixed gas of nitrogen gas at 300 ° C. or lower and 97% nitrogen and 3% hydrogen at 300 ° C. or higher. The inside of the firing furnace was heated to 1470 to 1485 ° C. at a temperature increase rate of 2.5 ° C./min. Then, it was heated and fired at a heating temperature of 1470 to 1485 ° C. for 5 to 7 hours. The powder obtained after heating and firing was cooled to room temperature at a cooling rate of 2.5 ° C./min. Thereby, a powder of substitutional type titanium trioxide was obtained. The obtained substitutional titanium pentoxide powder is subjected to diffraction measurement with an X-ray diffractometer, and the result is compared with X-ray diffraction data of trititanium pentoxide containing a β1-type phase to obtain β1-type It was confirmed that it was a substitution type titanium trioxide containing a phase.

Further, the substitution type titanium pentoxide including a β1 type phase whose substitution atom is Hf and the substitution rate is 10 at%, and the substitution atom is Sc and the substitution rate is 3 at% and β1 of 3.5 at%. A substituted type titanium trioxide containing a mold phase was synthesized as follows.

Table 1 shows metal titanium powder (average particle diameter of about 20 μm), rutile-type titanium dioxide powder (average particle diameter of about 5 μm), and components containing atoms shown in the column “Substitution Atom” in Table 1. The mixture was prepared by mixing so that the “substitution ratio” was obtained. The mixture was pelletized, placed in a vacuum chamber, and heated and fired while being exposed to arc discharge under an argon gas atmosphere with a gas pressure set to about −0.05 MPa. The powder obtained after heating and firing was rapidly cooled by a water-cooled copper plate at a cooling rate of about 100 to 1000 ° C./min. Thereby, a powder of substitutional type titanium trioxide was obtained. The obtained substitution type trititanium pentoxide powder is subjected to diffraction measurement with an X-ray diffractometer, and the result is compared with the X-ray diffraction data of trititanium pentoxide to have a λ phase and a β1 type phase. It was confirmed that it was a substitution type titanium trioxide.

8 and 9 show the X-ray diffraction patterns of the substituted trititanium pentoxides obtained in (1-1) above. In FIG. 8, FIG. 8A is an X-ray diffraction pattern of substitutional type trititanium pentoxide in which the substitution atom is Hf and the substitution ratio is 10 at%, 5 at%, 3 at%, and 1 at% in order from the top. FIG. 8B is an X-ray diffraction pattern of substituted trititanium pentoxide in which the substitution atom is Zr and the substitution ratio is 3 at% and 1 at% in order from the top. FIG. 8C is an X-ray diffraction pattern of substitutional trititanium pentoxide in which the substitution atom is Si and the substitution ratio is 3 at% and 1 at% in order from the top. FIG. 8D is an X-ray diffraction pattern of substitutional trititanium pentoxide in which the substitution atom is Sc and the substitution ratio is 3.5 at%, 3 at%, and 1 at% in order from the top. FIG. 8E is an X-ray diffraction pattern of substitutional type trititanium pentoxide in which the substitution atom is Y and the substitution ratio is 3 at% and 1 at% in order from the top. Further, in FIG. 9, FIG. 9A shows a substitutional type in which the substitution atoms are Hf and Zr, and the substitution ratio is Hf1.5 at% and Zr1.5 at%, and Hf 0.5 at% and Zr 0.5 at% in order from the top. It is an X-ray diffraction pattern of trititanium oxide. FIG. 9B is an X-ray diffraction pattern of substitutional type trititanium pentoxide having substitution atoms of Hf and Si, Hf3 at% and Si 5 at%, and Hf 0.5 at% and Zr 0.5 at%. FIG. 9C shows X-rays of substituted trititanium pentoxide in which the substitution atoms are Sc and Y, and the substitution ratios are Sc1.5 at% and Y1.5 at%, and Sc0.5 at% and Y0.5 at% from the top. It is a diffraction pattern.

(1-2) Synthesis of substitutional type titanium trioxide (β2 type phase) Titanium metal powder (average particle size of about 20 μm), rutile type titanium dioxide powder (average particle size of about 5 μm), The components containing the atoms shown in the “Atom” column were mixed so as to have the “substitution ratio” shown in Table 1 to prepare a mixture. The mixture was pelletized, placed in a vacuum chamber, and heated and fired while being exposed to arc discharge under an argon gas atmosphere with a gas pressure set to about −0.05 MPa. The powder obtained after heating and firing was rapidly cooled by a water-cooled copper plate at a cooling rate of about 100 to 1000 ° C./min. Thereby, a powder of substitutional type titanium trioxide was obtained. In addition, the obtained substitution type trititanium pentoxide powder is subjected to diffraction measurement with an X-ray diffractometer, and the result is compared with X-ray diffraction data of trititanium pentoxide containing a β2-type phase. It was confirmed that it was a substituted trititanium pentoxide containing a β2-type phase.

Incidentally, the X-ray crystal diffraction patterns of the substituted trititanium pentoxides obtained in the above (1-2) are shown in FIG. 10 and FIG. In FIG. 10, FIG. 10A is an X-ray diffraction pattern of substituted trititanium pentoxide in which the substitution atom is Hf and the substitution ratio is 3 at% and 1 at% in order from the top. FIG. 10B is an X-ray diffraction pattern of substitutional trititanium pentoxide in which the substitution atom is Zr and the substitution ratio is 3 at% and 1 at% in order from the top. FIG. 10C is an X-ray diffraction pattern of substitutional type trititanium pentoxide in which the substitution atom is Si and the substitution ratio is 3 at% and 1 at% in order from the top. FIG. 10D is an X-ray diffraction pattern of substitutional trititanium pentoxide in which the substitution atom is Sc and the substitution ratio is 2 at% and 1 at%. FIG. 10E is an X-ray diffraction pattern of substitutional trititanium pentoxide in which the substitution atom is Y and the substitution ratio is 3 at% and 1 at% from the top. FIG. 10F is an X-ray diffraction pattern of unsubstituted trititanium pentoxide. Also, in FIG. 11, FIG. 11A shows a substitution type in which the substitution atoms are Hf and Zr, and the substitution ratios are Hf 1.5 at% and Zr 1.5 at%, and Hf 0.5 at% and Zr 0.5 at% in order from the top. It is an X-ray diffraction pattern of trititanium oxide. FIG. 11B is an X-ray diffraction pattern of substitutional type trititanium pentoxide having substitution atoms of Hf and Si, Hf1.5 at% and Si 1.5 at%, and Hf 0.5 at% and Si 0.5 at%. FIG. 11C shows an X-ray of a substituted trititanium pentoxide in which the substitution atoms are Sc and Y, and the substitution ratios are Sc1.5 at% and Y1.5 at%, and Sc0.5 at% and Y0.5 at% in order from the top. It is a diffraction pattern.

In addition, the component containing the substitution atom corresponding to the “substitution atom” shown in Tables 1 and 2 is as follows. In addition, components substituted with two or more kinds of substituent atoms were prepared by mixing the following corresponding components at a ratio of 1: 1.
Hf: Hafnium oxide (IV).
Zr: zirconium oxide (IV).
Sc: scandium oxide (III).
Y: Yttrium oxide (III).
Si: Silicon oxide (IV).

(2) Evaluation of Substitutional Type Titanium Pentoxide (2-1) Thermal Behavior of Substitutional Type Titanium Pentoxide Powders of Substitutional Type Titanium Pentoxide Obtained in (1-1) and (1-2) The phase transition temperature and endothermic amount at the time of phase transition were measured by a differential scanning calorimetry. In the measurement, a DSC apparatus (model number DSC 220c, manufactured by Seiko Denshi Kogyo Co., Ltd.) was used. / Min. Tables 1 and 2 below show the phase transition temperature, endothermic amount, or heat release amount obtained from the results. FIG. 1A shows a graph showing the thermal behavior of substituted trititanium pentoxide obtained in (1-1) with the substitution atom being Hf and the substitution ratio being 3 at%. FIG. 1B shows a graph showing the thermal behavior of substituted trititanium pentoxide obtained in (1-2) with the substitution atom being Hf and the substitution ratio being 3 at%. The solid line in FIGS. 1A and 1B indicates the behavior when the temperature is raised, and the broken line indicates the behavior when the temperature is lowered. As a result, it was found that the Hf-substituted type titanium trioxide of (1-1) undergoes phase transition with endotherm during the temperature rising process, but does not release heat and does not cause phase transition during the temperature lowering process. That is, it was suggested that Hf-substituted trititan pentoxide having a β1-type phase undergoes a phase transition to a λ-type phase during the temperature rising process, whereas the λ-type phase does not undergo a phase transition during the temperature lowering process. It was also found that (1-2) Hf-substituted trititanium pentoxide undergoes phase transition with endotherm during the temperature rising process and phase transition with heat dissipation during the temperature lowering process. That is, it was suggested that Hf-substituted trititanium pentoxide having a β2-type phase undergoes a phase transition to an α-type phase during the temperature rising process and a phase transition from the α-type phase to the β2-type phase during the temperature lowering process. All the substituted atoms showed the same behavior.

(2-2) Pressure characteristics of substitutional type titanium trioxide (pressure response)
The substituted trititanium pentoxide powder substituted with Hf obtained in (1-1) was subjected to X-ray diffraction measurement again after applying a pressure of 600 MPa for 15 seconds using a pressure device.

FIG. 2 shows an X-ray diffraction pattern of the substituted trititanium pentoxide in Example 1 before and after applying pressure. In FIG. 2, the horizontal axis represents the diffraction angle (2θ: 2theta), and the vertical axis represents the intensity (Intensity). In FIG. 2, the X-ray diffraction pattern before applying pressure is shown on the lower side, and the X-ray diffraction pattern after applying pressure is shown on the upper side. According to FIG. 2, in the X-ray diffraction pattern after the pressure is applied, 2θ derived from the λ phase has two peaks around 18 degrees (in FIG. 2) compared to the X-ray diffraction pattern before the pressure is applied. Peaks A1 and A2) are weakened, and a peak around 20.5 degrees 2θ derived from the β phase (peak B in FIG. 2) is strong.

Thus, it was found that the substituted trititanium pentoxide having a β1 type phase and substituted with Hf has pressure responsiveness. In addition, the pressure responsiveness was similarly exhibited with other substitution atoms.

(3) Synthesis of mixed-type trititanium pentoxide About 0.5 g of rutile-type titanium dioxide having an average particle size of about 5 μm was placed in a firing furnace (Tamman tube furnace), and the production of the mixed-type trititanium pentoxide was described. A mixed type trititanium pentoxide was obtained by sequentially performing five steps from the first step to the fifth step. Specifically, the conditions in each step are as follows. In the first step, the inside of the firing furnace was kept in a nitrogen gas atmosphere and heated to 200 ° C. at a rate of temperature increase of 1.6 ° C./min. In the second step, the inside of the firing furnace was held at 200 ° C. for 10 minutes while maintaining the nitrogen gas atmosphere. In the third step, the temperature in the firing furnace is set to switch from the nitrogen gas atmosphere to a mixed gas atmosphere of 97% nitrogen and 3% hydrogen when the temperature reaches 300 ° C. or higher. Heated to the range of 1450 to 1500 ° C. for min. In the fourth step, the inside of the firing furnace was maintained in the range of 1450 to 1500 ° C. in a mixed gas atmosphere of 97% nitrogen and 3% hydrogen. In the fifth step, the temperature in the firing furnace is set so that the mixed gas atmosphere is switched to the nitrogen gas atmosphere when the temperature in the firing furnace reaches 300 ° C. or lower, and the temperature in the firing furnace is lowered to room temperature at a temperature drop rate of 2.5 ° C./min. Was lowered. In Examples 1 to 7, as shown in Table 3, the second heating temperature and the second maintenance time in the conditions of the fourth step were varied.

X-ray diffractometry of the obtained mixed trititanium pentoxide powder was performed with an X-ray diffractometer manufactured by Rigaku Corporation, model number RINT2500. As a result, in each of the X-ray diffraction patterns of Examples 1 to 7, a peak derived from the λ phase and a peak derived from the β phase were confirmed. In addition, as shown in FIG. 4, the peak of 2θ derived from the λ phase is approximately equal to the peak position in Examples 1 to 7, and the mixed type trititanium pentoxide is substantially the same in each example. It was suggested to have an equivalent crystal structure. In FIG. 4, (a) is Example 1, (b) is Example 2, (c) is Example 3, (d) is Example 4, (e) is Example 5, and (f) is Example. Examples 6 and (g) are part of the X-ray diffraction patterns of Example 7. Further, the λ phases in the mixed type trititanium pentoxide of Examples 1 to 7 have substantially the same inter-axis angle β, and the inter-axis angle β of the λ phase in the mixed type trititanium pentoxide is all It was found to be 91.29 degrees or less and have a smaller inter-axis angle β than the conventional λ phase of titanium trioxide.

In addition, each example was obtained by using the reference intensity ratio (RIR value) described in the database from the integrated intensity at the strongest line of the test component in the X-ray diffraction pattern by the RIR method from the obtained X-ray diffraction pattern. The mass ratio between the β phase and the λ phase was calculated, and the results are shown in Table 3 below.

In addition, the phase transition temperature of the mixed trititanium pentoxide powder of each example and the endothermic amount at the phase transition were measured by a differential scanning calorimetry. In the measurement, a DSC device (model number DSC 220c manufactured by Seiko Denshi Kogyo Co., Ltd.) was used. Air gas was flowed at 100 mL / min, the temperature range was from room temperature to 300 ° C., the temperature increase rate was 10 ° C./min, and the temperature decrease (cooling) rate was 10 ° C. / Min. The results are shown in Table 1 below. 3A is a graph showing the thermal behavior of the mixed trititanium pentoxide in Example 1, and FIG. 3B is a graph showing the thermal behavior of the mixed trititanium pentoxide in Example 7. The solid line in FIGS. 3A and 3B indicates the behavior at the time of temperature rise, and the broken line indicates the behavior at the time of temperature decrease. As a result, it was found that the mixed type trititanium pentoxide undergoes phase transition with endotherm in the temperature rising process, but does not release heat and does not cause phase transition in the temperature lowering process.

Further, as Comparative Example 1, β-trititanium pentoxide powder was prepared. The β-trititanium pentoxide of Comparative Example 1 was obtained as follows. Metal titanium powder (average particle size of about 20 μm) and rutile titanium dioxide powder (average particle size of about 5 μm) were mixed to prepare a mixture. The mixture was pelletized, placed in a vacuum chamber, and heated and fired while being exposed to arc discharge under an argon gas atmosphere with a gas pressure set to about −0.05 MPa. The powder obtained after heating and firing was rapidly cooled by a water-cooled copper plate at a cooling rate of about 100 to 1000 ° C./min. As a result, β-trititanium pentoxide was obtained. In Comparative Example 1, the phase transition temperature and the endothermic amount were measured in the same manner as in Examples 1-7. The results are also shown in Table 3 below.

It was found that any of the mixed type trititanium pentoxides of any of the Examples had a lower phase transition temperature than β-trititanium pentoxide of Comparative Example 1.

(4) Pressure characteristics of mixed type titanium trioxide (pressure response)
The powder obtained in (3) was subjected to X-ray diffraction measurement again after applying a pressure of 1.4 GPa for 15 seconds using a pressure device (TYPE P-6 manufactured by Riken Seiki Co., Ltd.).

FIG. 5 shows an X-ray diffraction pattern of the mixed type trititanium pentoxide in Example 1 before and after applying pressure. In FIG. 5, the horizontal axis represents the diffraction angle (2θ: 2 theta), and the vertical axis represents the intensity (Intensity). In FIG. 5, the X-ray diffraction pattern before applying pressure is shown on the lower side (solid line), and the X-ray diffraction pattern after applying pressure is shown on the upper side (broken line). According to FIG. 3, in the X-ray diffraction pattern after the pressure is applied, 2θ derived from the β phase is a peak around 19 degrees (peak C in FIG. 5) compared to the X-ray diffraction pattern before the pressure is applied. ) And 2θ are peaks near 21 degrees (peak B in FIG. 5), and 2θ derived from the λ phase is near 18 degrees (peak A in FIG. 5) are weak.

Thus, it was found that the mixed type trititanium pentoxide of Example 1 has pressure response. In Examples 2 to 7, the mixed type trititanium pentoxide exhibited pressure responsiveness as in Example 1.

[Summary]
As is apparent from the above, in the trititanium pentoxide material of the first aspect according to the present invention, a part of Ti of trititanium pentoxide is selected from the group consisting of Hf, Zr, Si, Sc, and Y. And a composition substituted with at least one kind of substituent atom.

According to the first aspect, a trititanium pentoxide material having a lower phase transition temperature than trititanium pentoxide can be obtained.

In the first aspect, the tritium pentoxide material of the second aspect is 1 at% or more with respect to the total amount of Ti and substituent atoms in the trititanium pentoxide material.

According to the second aspect, a trititanium pentoxide material having a lower phase transition temperature than that of trititanium pentoxide can be obtained.

The trititanium pentoxide material of the third aspect is the sum of Ti and the substituent atom in the trititanium pentoxide material in the first aspect, wherein the substitution atoms include at least one of Hf and Sc. The total amount of Hf and Sc with respect to the amount is 1 at% or more.

According to the third aspect, the trititanium pentoxide-based material can have a particularly lower phase transition temperature than trititanium pentoxide.

In any one of the first to third aspects, the tritium pentoxide-based material of the fourth aspect is the amount of substitution atoms relative to the total amount of Ti and substitution atoms in the substitution type trititanium pentoxide, 10 at% or less.

According to the fourth aspect, the phase transition temperature of the trititanium pentoxide material can be made lower than that of trititanium oxide, and the excellent endothermic characteristics of the trititanium pentoxide material can be maintained.

In the fifth aspect of the trititanium pentoxide material according to any one of the first to fourth aspects, the number of substituent atoms is two or more.

According to the fifth aspect, the trititanium pentoxide-based material can have a lower phase transition temperature than trititanium pentoxide.

A titanium trioxide pentoxide material according to a sixth aspect is the λ-trititanium pentoxide type material according to any one of the first to fifth aspects, from a β-type phase having a β-trititanium pentoxide structure. It has a phase transition temperature for phase transition to a λ-type phase having the structure:

According to the sixth aspect, the trititanium pentoxide-based material can have a lower phase transition temperature than trititanium pentoxide.

The titanium trioxide pentoxide-based material according to the seventh aspect is the α-trititanium pentoxide type from the β-type phase having the structure of β-trititanium pentoxide type in any one of the first to fifth aspects. It has a phase transition temperature for phase transition to an α-type phase having the structure:

According to the seventh aspect, the trititanium pentoxide-based material can have a lower phase transition temperature than trititanium pentoxide.

The trititanium pentoxide material according to the eighth aspect has a β phase having a β-type structure and a λ phase having a λ-type structure.

According to the eighth aspect, the trititanium pentoxide material has a lower phase transition temperature than β-trititanium pentoxide.

In the ninth aspect, the trititanium pentoxide material of the ninth aspect is the eighth aspect, wherein the inter-axis angle β of the crystal lattice of the λ phase in the trititanium pentoxide material is less than 91.29 degrees.

According to the ninth aspect, the trititanium pentoxide material has a lower phase transition temperature.

The tritium pentoxide material of the tenth aspect is the same as that of the eighth or ninth aspect, in which the phase transition temperature at which the β phase in the trititanium pentoxide material transitions to the λ phase is composed of only the β phase. Lower than the phase transition temperature of trititanium oxide.

According to the tenth aspect, the trititanium pentoxide material has a lower phase transition temperature.

The method for controlling the phase transition temperature of the trititanium pentoxide material of the eleventh aspect is characterized in that β in a titanium pentoxide material having a β phase having a β-type structure and a λ phase having a λ-type structure. By adjusting the ratio of the phase to the λ phase, the phase transition temperature at which the β phase in the trititanium pentoxide material transitions to the λ phase is set to a temperature lower than the phase transition temperature of β-trititanium pentoxide. Control.

According to the eleventh aspect, the phase transition temperature of the trititanium pentoxide material can be set to the target temperature or close to the target temperature.

The endothermic method according to the tenth aspect is the heat absorption method according to any one of the eighth to tenth aspects, wherein heat is applied to the trititanium pentoxide material to convert the β phase in the trititanium pentoxide material into the λ phase. By transferring, the tritium pentoxide material absorbs heat.

According to the tenth aspect, the ambient heat can be absorbed into the trititanium pentoxide material at a temperature lower than that of β-titanium pentoxide.

According to a thirteenth aspect of the method for converting a trititanium pentoxide material, in any one of the eighth to tenth aspects, the β-phase in the trititanium pentoxide-based material is transformed into a λ phase. By giving an external field to the product to be produced, the λ phase in the product is phase-shifted to the β phase.

According to the thirteenth aspect, the λ phase can be transformed into β-trititanium pentoxide by phase transition.

The sensor element according to the fourteenth aspect includes the trititanium pentoxide material according to any one of the first to tenth aspects.

In the fourteenth aspect, it is possible to output a discontinuous change in physical properties of the trititanium pentoxide material accompanying a phase transition or a phenomenon caused by this change. Further, it can be used as a sensor for various applications that can respond to surrounding external stimuli.

The storage battery management system (1) of the fifteenth aspect performs management processing based on the sensor element (3) of the fourteenth aspect and the sensor element (3) to which heat generated by the storage battery (2) is transmitted. And a processing unit (4) to perform.

In the fifteenth aspect, when charging / discharging the storage battery (2), when the sensor element (3) detects a heat generation state exceeding the temperature during normal use of the storage battery (2), the processing unit (4) Appropriate management processing.

According to a sixteenth aspect of the method for producing a trititanium pentoxide material, titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y are mixed. The mixture is heated by placing it under a hot hydrogen atmosphere.

According to the sixteenth aspect, a trititanium pentoxide material having a phase transition temperature lower than that of trititanium pentoxide can be produced.

According to a seventeenth aspect of the method for producing a trititanium pentoxide material, titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y are mixed. The mixture is exposed to an arc discharge under an inert gas atmosphere.

According to the seventeenth aspect, a trititanium pentoxide material having a phase transition temperature lower than that of trititanium pentoxide can be produced.

DESCRIPTION OF SYMBOLS 1 Storage battery management system 2 Storage battery 3 Sensor element 4 Processing part

Claims (17)

Having a composition in which a part of Ti of trititanium pentoxide is substituted with at least one substituent atom selected from the group consisting of Hf, Zr, Si, Sc, and Y;
Titanium pentoxide material. The amount of the substitution atoms relative to the total amount of Ti and the substitution atoms in the trititanium pentoxide material is 1 at% or more.
The trititanium pentoxide material according to claim 1. The substituent atom includes at least one of the Hf and the Sc,
The total amount of Hf and Sc relative to the total amount of Ti and the substituent atoms in the trititanium pentoxide material is 1 at% or more.
The trititanium pentoxide material according to claim 1. The amount of the substitution atoms with respect to the total amount of Ti and the substitution atoms in the trititanium pentoxide material is 10 at% or less.
The trititanium pentoxide material according to any one of claims 1 to 3. There are two or more substituent atoms.
The trititanium pentoxide material according to any one of claims 1 to 4. having a phase transition temperature for phase transition from a β-type phase having a β-trititanium pentoxide type structure to a λ-type phase having a λ-trititanium pentoxide type structure;
The trititanium pentoxide material according to any one of claims 1 to 5. having a phase transition temperature for phase transition from a β-type phase having a β-trititanium pentoxide type structure to an α-type phase having an α-trititanium pentoxide type structure;
The trititanium pentoxide material according to any one of claims 1 to 5. having a β-phase having a β-type structure and a λ-phase having a λ-type structure;
Titanium pentoxide material. The inter-axis angle β of the crystal lattice of the λ phase in the trititanium pentoxide material is less than 91.29 degrees.
The trititanium pentoxide-based material according to claim 8. The phase transition temperature at which the β phase in the trititanium pentoxide-based material undergoes phase transition to the λ phase is lower than the phase transition temperature of trititanium pentoxide consisting of only the β phase.
The trititanium pentoxide material according to claim 8 or 9. By adjusting the ratio of β phase and λ phase in the trititanium pentoxide material having the β phase having the β type structure and the λ phase having the λ type structure, Controlling the phase transition temperature at which the β phase of the phase transition to the λ phase is lower than the phase transition temperature of β-trititanium pentoxide,
Control method of phase transition temperature of trititanium pentoxide material. A heat is applied to the trititanium pentoxide material according to any one of claims 8 to 10 to cause the β phase in the trititanium pentoxide material to undergo a phase transition to the λ phase, whereby the trititanium pentoxide material is changed. Make the material absorb heat,
Endothermic method. The β-phase in the trititanium pentoxide-based material according to any one of claims 8 to 10 is given an external field to a product generated by the phase transition of the β-phase to the λ phase. phase transition from λ phase to β phase,
Conversion method of trititanium pentoxide material. Comprising the trititanium pentoxide-based material according to any one of claims 1 to 10,
Sensor element. The sensor element according to claim 14, wherein heat generated by the storage battery is transmitted,
A processing unit that performs management processing based on the output of the sensor element;
Comprising
Storage battery management system. A mixture of titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y is heated by being placed in a high-temperature hydrogen atmosphere.
A method for producing a trititanium pentoxide material. Exposing a mixture of titanium oxide and a component containing at least one atom selected from the group consisting of Hf, Zr, Si, Sc, and Y to arc discharge under an inert gas atmosphere;
A method for producing a trititanium pentoxide material.

Images