Energy absorption and release materials

Abstract

The present invention provides a material having a higher electromagnetic wave absorption capacity than in conventional electromagnetic wave absorption materials. The present invention pertains to an energy absorption and release material characterized by comprising titanium suboxide represented by a compositional formula of TiOx (where x represents a number satisfying 1 ≤ x < 1.8), the specific surface area being 5 m2 / g or above and the average particle diameter / specific surface area equivalent particle diameter being 0.5 to 3.0.

Description

[Technical Field]

[0001] The present invention relates to an energy absorbing and releasing material. [Background technology]

[0002] In recent years, the use of electromagnetic waves ranging from microwaves to millimeter waves (GHz band) has rapidly expanded, and they are now used in a wide variety of applications, including personal computers, mobile phones, various electronic devices using wireless LAN, microwave ovens, satellite broadcasting, and radar. However, concerns have arisen about the effects of the use of various electromagnetic waves in daily life on the human body. Furthermore, radars used for purposes such as automobile collision prevention and autonomous driving have been found to malfunction due to external electromagnetic waves. As one way to resolve these issues, research has been conducted into materials that absorb electromagnetic waves. Technologies have been reported that use dielectric materials such as titanium oxide and barium titanate, magnetic materials such as iron oxide, and carbon, mixed with various resins and fibers, to absorb electromagnetic waves and block unwanted electromagnetic waves (see Patent Documents 1 and 2). Furthermore, temperature-regulating materials that utilize materials with electromagnetic wave absorption capabilities to heat food at a uniform temperature in an electromagnetic microwave oven have been reported (see Patent Documents 3 to 5). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4859791 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-169804 [Patent Document 3] Japanese Patent Application Publication No. 2019-102665 [Patent Document 4] Japanese Patent Application Publication No. 2018-189250 [Patent Document 5] Japanese Patent Application Laid-Open No. 2013-239459 Summary of the Invention [Problem to be solved by the invention]

[0004] As mentioned above, electromagnetic wave absorbers have been proposed as a way to prevent the harmful effects of electromagnetic waves on the human body and equipment, and methods have also been proposed for utilizing the properties of electromagnetic wave absorbers to regulate temperature. However, carbon, a dielectric electromagnetic wave absorber, can absorb excessive electromagnetic waves and ignite, or can deteriorate the properties of surrounding resins and fiber materials due to excessive heat generation and heat storage. Iron oxide, a magnetic electromagnetic wave absorber, has insufficient electromagnetic wave absorption capacity due to its reduced relative permeability in the GHz band. As such, conventional electromagnetic wave absorbers are not sufficient in terms of performance. Furthermore, electromagnetic wave absorbers are sometimes mixed into resins, fiber materials, etc., and when mixed in large amounts for the purposes of electromagnetic wave blocking or temperature regulation, the properties of the resins, fiber materials, etc. may change, potentially deteriorating various properties. For this reason, there is a demand for materials with high electromagnetic wave absorption capacity that can exert sufficient electromagnetic wave absorption capacity even when used in small amounts.

[0005] In view of the above-mentioned current situation, an object of the present invention is to provide a material having a higher electromagnetic wave absorbing ability than conventional electromagnetic wave absorbing materials. [Means for solving the problem]

[0006] The present inventors have investigated materials with higher electromagnetic wave absorption capacity than conventional electromagnetic wave absorbers, and have found that the degree of aggregation of titanium suboxide particles affects the heating rate when absorbing electromagnetic waves and the heat release rate after heating. They have also found a material with a composition formula of TiOx (x represents a number of 1≦x<1.8) and a specific surface area of ​​5m 2 It has been discovered that titanium suboxide with a small particle size of 1 / g or more, and with a ratio of average particle size to particle size converted to specific surface area within a specified range, rapidly increases in temperature when irradiated with electromagnetic waves, has excellent electromagnetic wave absorption ability, and rapidly releases the absorbed energy as heat, making it an excellent material for absorbing and releasing energy such as electromagnetic waves and heat. Electromagnetic waves refer to radio waves with a wavelength longer than 0.1 mm and light with a wavelength shorter than 0.1 mm and longer than 10 nm. Light refers to electromagnetic waves in the ranges of ultraviolet, visible, and infrared radiation.

[0007] That is, the present invention is directed to a titanium dioxide powder having a composition formula of TiOx (x represents a number of 1≦x<1.8) and a specific surface area of ​​5 m 2 / g or more, and the ratio of average particle diameter to specific surface area converted particle diameter is 0.5 to 3.0.

[0008] The energy absorption / release material has a complex relative permittivity of 25 or more at a frequency of 1 GHz and a dielectric loss tangent of 2.6×10 -2 It is preferable that this is equal to or greater than this.

[0009] The energy absorbed by the energy absorbing / releasing material is preferably electromagnetic waves.

[0010] The present invention also relates to a resin material containing the energy absorbing / releasing material of the present invention and a resin.

[0011] The present invention also relates to a fiber material comprising the energy absorbing and releasing material of the present invention and organic and / or inorganic fibers.

[0012] The present invention also relates to a ceramic material comprising the energy absorption / release material of the present invention and a ceramic. [Effects of the Invention]

[0013] The energy absorption / release material of the present invention heats up faster than conventional titanium oxides or iron oxides when irradiated with electromagnetic waves such as radio waves or light in the GHz band, and does not ignite like carbon. Because it also has a fast heat dissipation rate, it can be suitably used as an electromagnetic wave absorbing material that exhibits high electromagnetic wave absorption properties, or as a temperature adjusting material in environments heated by energy such as electromagnetic waves. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing the results of electron microscope observation of the titanium suboxide produced in Example 1. [Figure 2]FIG. 1 is a diagram showing the results of electron microscope observation of the titanium suboxide produced in Example 2. [Figure 3] FIG. 1 is a diagram showing the results of electron microscope observation of the titanium suboxide produced in Example 3. [Figure 4] FIG. 1 is a diagram showing the results of electron microscope observation of the titanium suboxide produced in Comparative Example 3. [Figure 5] FIG. 1 is a diagram showing the results of electron microscope observation of the titanium suboxide produced in Comparative Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the present invention will be specifically described below, but the present invention is not limited to the following description and can be appropriately modified and applied within the scope that does not change the gist of the present invention.

[0016] 1. Energy absorption and release materials The energy absorption / release material of the present invention has excellent energy absorption properties, such as quickly absorbing energy from electromagnetic waves and heating, and also has excellent heat dissipation properties, such as releasing energy as heat, and therefore can be suitably used as an electromagnetic wave absorption material or a temperature regulating material. The energy absorption / release material of the present invention is represented by the composition formula TiOx (x represents a number of 1≦x<1.8), and has a specific surface area of ​​5 m 2 / g or more, and the ratio of average particle diameter to specific surface area converted particle diameter is 0.5 to 3.0. The average particle size measured by the method described in the Examples below represents the particle size of the aggregates when the particles are fused together, whereas the specific surface area-equivalent particle size is a method for determining particle size by converting specific surface area measurements using a gas adsorption method, and is not affected by the state of aggregation due to fusion. Therefore, the ratio of average particle size / specific surface area-equivalent particle size represents the state of aggregation due to fusion of particles, with a larger value indicating greater aggregation due to fusion. The present invention is based on the discovery that the degree of aggregation of titanium suboxide particles affects their energy absorption / release capacity, and that titanium suboxide with an aggregation degree of approximately 0.5 to 3.0 in terms of average particle size / specific surface area-equivalent particle size exhibits excellent heating rates when absorbing energy such as electromagnetic waves or heat, and excellent heat release rates after heating. The ratio of the average particle size of the titanium suboxide to the particle size converted into specific surface area is 0.5 to 3.0, preferably 0.6 to 2.0, and more preferably 0.8 to 1.2.

[0017] The energy absorption / release material of the present invention is made of titanium suboxide represented by the composition formula TiOx (x is a number in the range of 1≦x<1.8), but the x is more preferably a number in the range of 1.3≦x<1.8, and even more preferably a number in the range of 1.42≦x<1.78. The value of x in the composition TiOx of the titanium suboxide powder can be calculated by the method shown in the examples below.

[0018] The above titanium suboxide has a specific surface area of ​​5m 2 / g or more, but the specific surface area is 8m 2 / g or more is preferable. More preferably, the specific surface area is 10 m 2 / g or more. The specific surface area of ​​titanium suboxide can be measured by the method shown in the examples below.

[0019] The energy absorption / release material of the present invention has a complex relative permittivity of 25 or more at a frequency of 1 GHz and a dielectric loss tangent of 2.6×10 -2 It is preferable that this is equal to or greater than this. If the energy absorption / release material of the present invention has such properties, it will have excellent electromagnetic wave absorption ability and also excellent ability to convert the absorbed electromagnetic wave energy into thermal energy and release it, making it more suitable as an electromagnetic wave absorption material. The real part of the complex relative permittivity of the energy absorbing and releasing material of the present invention at a frequency of 1 GHz is more preferably 28 or more, and even more preferably 30 or more. The dielectric loss tangent of the energy absorption / release material of the present invention is more preferably 3.0×10 -2 More preferably, it is 5.0 × 10 -2 That's all. The real part of the complex relative permittivity and the dielectric loss tangent at a frequency of 1 GHz of the energy absorbing / releasing material can be measured by the method described in the examples below.

[0020] The above titanium suboxide is L * a * b * L in color space * Value 0≦L * ≦50 and b * The value is b * It is preferable that the lightness L is ≦-2. * The larger the value, the brighter the color and the closer it is to white. * The smaller the value, the darker the color becomes, and the closer it is to black. * The larger the positive value, the closer to yellow the color becomes, and conversely, the smaller the negative value, the closer to blue the color becomes. The titanium suboxide represented by the composition formula TiOx (1≦x<1.8) in the present invention has an L value in this range. * value, b * If the material has a high saturation energy absorption / release property, it will be a better energy absorption / release material. Titanium suboxide L * The value is 30≦L * It is more preferable that the ratio is ≦45. Even more preferable that the ratio is 30≦L * ≦40. * The value is b * It is more preferable that b is ≦−2.2. * ≦-2.5. Titanium suboxide L* value, b * The value can be measured by the method described in the Examples below.

[0021] The above titanium oxide has a volume resistivity of 1.0 x 10 -2 It is preferable that the volume resistivity is Ω·cm or more. A high volume resistivity is advantageous in converting the absorbed electromagnetic wave energy into heat and releasing it. The volume resistivity is more preferably 1.0×10 -1 Ω·cm or more, and more preferably 1.0×10 1 It is over Ω·cm. The volume resistivity of titanium oxide can be measured by the method described in the examples below.

[0022] As described above, the energy absorption / release material of the present invention has excellent energy absorption properties, quickly absorbing energy such as electromagnetic waves and heat to be heated, and also has excellent heat dissipation properties, releasing energy as heat. Therefore, it can be suitably used as an electromagnetic wave absorption material, a temperature regulating material, and also as a material for an electromagnetic wave heating catalyst. Thus, one of the preferred embodiments of the present invention is that the energy to be absorbed is electromagnetic waves.

[0023] The energy absorbing / releasing material of the present invention has a high real part of complex dielectric constant and a high dielectric loss tangent, and thus has a high electron storage capacity. Furthermore, the energy absorbing / releasing material of the present invention has a lower volume resistivity than conventional titanium oxides, and is highly capable of conducting electrons from the outside to the energy absorbing / releasing material of the present invention and of conducting stored electrons to the outside. Therefore, the energy absorbing / releasing material of the present invention can be suitably used, for example, as an inorganic filler for condensers, capacitors, target materials, magnetic memories, optical information recording media, charge storage memories, color filters, transfer belts, antenna substrates, etc., as an oxide semiconductor layer for dye-sensitized solar cells and perovskite solar cells, as a positive electrode coating material for secondary batteries, and as a pre-dope material. Furthermore, the energy absorbing / releasing material of the present invention has a low brightness like carbon used as a black pigment and a high ability to rapidly dissipate heat, and therefore can be suitably used, for example, as a dark blue or black pigment with low brightness, a dye, or a semiconductor encapsulant.

[0024] The energy absorbing and releasing material of the present invention may be used alone or in combination with other materials such as resins, organic and / or inorganic fibers, metals, ceramics, and the like. Examples of resins that can be used include bismaleimide resin, epoxy resin, polyimide resin, polysulfone resin, polyamideimide resin, polyetherimide resin, polyethersulfone resin, polybenzimidazole resin, silicone resin, phenolic resin, polyester resin, polyvinyl ester resin, polyurethane resin, melamine resin, cyanate ester resin, isocyanate resin, polybenzoxazole resin, polyvinyl alcohol resin, and modified resins thereof. Examples of fibers that can be used include organic fibers such as cotton, silk, hemp, wool, nylon, vinylon, polyester fibers, acrylic fibers, vinylidene chloride fibers, acetate, and rayon; and inorganic fibers such as glass fibers and carbon fibers. Examples of metals that can be used include alkali metals, alkaline earth metals, rare earth metals, titanium group, earth metals, chromium group, manganese group, iron group, platinum group, copper group, zinc group, aluminum group, carbon group, nitrogen group, and oxygen group metals. Examples of ceramics include metal oxides, metal non-oxides, glass, and porcelain. The energy absorbing / releasing material of the present invention and materials using these in combination are also part of the present invention. That is, a resin material containing the energy absorbing / releasing material of the present invention and a resin, a fiber material containing the energy absorbing / releasing material of the present invention and organic and / or inorganic fibers, a material containing the energy absorbing / releasing material of the present invention and a metal, and a ceramic material containing the energy absorbing / releasing material of the present invention and a ceramic are all part of the present invention.

[0025] 2. Manufacturing method of energy absorption / release material The energy absorbing / releasing material of the present invention is represented by the composition formula of TiOx (x represents a number of 1≦x<1.8), and has a specific surface area of ​​5 m 2The method for producing titanium suboxide having a particle size of 0.5 to 3.0 in terms of average particle size / specific surface area converted particle size is not particularly limited, but it can be produced by a production method including a step of firing a raw material containing titanium dioxide (TiO2) in a reducing atmosphere.

[0026] The crystal structure of titanium dioxide used as the raw material is not particularly limited, and any of rutile, anatase, and brookite types can be used, and mixtures of these types are also acceptable.

[0027] The titanium dioxide used as the raw material is not particularly limited, but it is preferable that the specific surface area is 5 to 400 m 2 / g is preferred. By using a material with such a specific surface area, titanium oxide can be fired more efficiently in a reducing atmosphere. More preferably, the specific surface area is 10 to 300 m 2 / g, and more preferably, the specific surface area is 50 to 200 m 2 / g. The specific surface area of ​​titanium dioxide can be measured by the method described in the examples below.

[0028] The raw material preferably also contains a reducing agent. Examples of the reduction aid include titanium metal, titanium hydride, and sodium borohydride, with titanium metal and titanium hydride being preferred. By subjecting a raw material further containing at least one of titanium metal and titanium hydride to calcination, titanium suboxide represented by the composition formula TiOx (x is a number in the range of 1≦x<1.8) can be obtained more efficiently. The content of the reducing agent (the total content when two or more types are included) is preferably 5 to 50 parts by weight, more preferably 8 to 40 parts by weight, calculated as metallic titanium, per 100 parts by weight of the total amount of titanium dioxide used as a raw material.

[0029] The raw materials may also contain additives other than reduction aids. Examples of additives other than reduction aids include agglomeration inhibitors, dispersants, fluxes, moisture absorbents, oxygen absorbers, heat-generating aids, etc. Examples of agglomeration inhibitors that can be used include oxides of aluminum, silicon, zinc, yttrium, zirconium, niobium, molybdenum, indium, tin, and rare earth elements, with silicon dioxide being preferred.

[0030] When using a mixture of two or more components (raw material mixture) as a raw material, the raw material mixture can be obtained by mixing the components using a conventional mixing method, but it is preferable to use a dry method. In other words, a dry mixture is preferable. This allows for more efficient production of titanium suboxide, which is represented by the composition formula TiOx (x is a number between 1 and 1.8). Each raw material component may be used alone or in combination of two or more.

[0031] When the raw material is fired in a reducing atmosphere (also referred to as reduction firing), the raw material may be fired as is, or if the raw material contains a solvent, the solvent may be removed before firing. The reducing atmosphere is not particularly limited, and examples thereof include a hydrogen (H2) atmosphere, a carbon monoxide (CO) atmosphere, a nitrogen (N2) atmosphere, a mixed gas atmosphere of hydrogen and carbon monoxide and / or nitrogen, a mixed gas atmosphere of hydrogen and an inert gas, and an ammonia (NH3) atmosphere. Of these, a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and nitrogen is preferred because it allows for efficient production of titanium suboxide powder. Furthermore, the reducing atmosphere is preferably one in which a reducing gas is continuously injected and flowing into the reaction field (also referred to as the system) where the reduction is taking place.

[0032] The raw materials may be fired once or twice or more times. When firing twice or more times, it is preferable that all steps are performed in a reducing atmosphere (preferably a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and nitrogen).

[0033] The firing temperature is preferably 500 to 1100°C, depending on the conditions of the reducing atmosphere such as the hydrogen concentration. 2 / g or more and a ratio of average particle size / particle size converted into specific surface area of ​​0.5 to 3.0 can be more efficiently obtained. The calcination temperature is more preferably 600 to 1050°C, and even more preferably 700 to 1000°C. In this specification, the firing temperature means the maximum temperature reached in the firing step.

[0034] The calcination time, i.e., the time for which the calcination temperature is maintained, also depends on the conditions of the reducing atmosphere, such as the hydrogen concentration, but is preferably, for example, 5 minutes to 100 hours. If the calcination time is within this range, the reaction proceeds more sufficiently, resulting in excellent productivity. It is more preferably 30 minutes to 48 hours, even more preferably 60 minutes to 24 hours, and particularly preferably 2 to 10 hours. When the temperature is lowered after the firing is completed, a gas other than hydrogen (for example, nitrogen gas) may be mixed or substituted.

[0035] The method for producing an energy absorption / release material of the present invention may include other steps, such as cooling the fired titanium suboxide and pulverizing the fired titanium suboxide, as long as it includes the step of firing a raw material containing titanium dioxide (TiO2) in a reducing atmosphere. [Example]

[0036] Specific examples are given below to explain the present invention in detail, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "wt%" mean "% by weight (% by mass)."

[0037] Example 1 Rutile-type titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "STR-100N", specific surface area 100 m 215.8 g of titanium hydride (1.4 g, manufactured by Toho Tech Co., Ltd., trade name "Titanium hydride powder TCH-450") was dry-mixed, and the mixture was placed in an alumina boat. The mixture was heated to 710°C over 68 minutes in an atmospheric firing furnace while 100 vol% hydrogen was passed through at 400 ml / min, and then held at 710°C for 8 hours. The mixture was then allowed to cool naturally to room temperature, yielding the powder of Example 1, which was identified as TiO having a Magneli structure in the XRD diffraction pattern measured by the method described below.

[0038] Example 2 Anatase-type titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "SSP-25", specific surface area 270 m 2 15.8 g of titanium dioxide (trade name: "Silica") (manufactured by Sigma-Aldrich Corporation), 2.8 g of silicon dioxide (trade name: "Silica"), and 2.8 g of titanium hydride (trade name: "Titanium hydride powder TCH-450") (manufactured by Toho Tech Co., Ltd.) were dry-mixed, and the mixture was placed in an alumina boat. The temperature was raised to 800°C over 77 minutes in an atmospheric firing furnace while 100 vol% hydrogen was passed through at 400 ml / min, and the temperature was maintained at 800°C for 8 hours. The powder was then naturally cooled to room temperature, and a powder of Example 2 was obtained, which was identified as TiO having a Magneli structure in the XRD diffraction pattern measured by the method described below.

[0039] Example 3 Rutile-type titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "STR-100N", specific surface area 100 m 2 15.8 g of titanium dioxide (1 / g) and 4.2 g of titanium hydride (manufactured by Toho Tech Co., Ltd., trade name "Titanium hydride powder TCH-450") were dry-mixed, then the mixture was placed in an alumina boat and heated to 710°C over 68 minutes in an atmospheric firing furnace while 100 vol% hydrogen was passed through at 400 ml / min. The temperature was then maintained at 710°C for 8 hours and the mixture was then naturally cooled to room temperature to obtain the powder of Example 3, which was identified as TiO having a corundum structure in the XRD diffraction pattern measured by the method described below.

[0040] Comparative Example 1 Rutile-type titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "STR-100N", specific surface area 100 m 220 g of the powder (1 / g) was placed in an alumina crucible, heated to 870°C in an electric furnace over 84 minutes, held at 870°C for 5 hours, and then naturally cooled to room temperature to obtain a powder of Comparative Example 1.

[0041] Comparative Example 2 Rutile-type titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "STR-100N", specific surface area 100 m 2 / g) was used.

[0042] Comparative Example 3 Anatase-type titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "SSP-25", specific surface area 270 m 2 3 g of the powder (100 vol. / g) was placed in an alumina boat, and the boat was heated to 1000°C over 97 minutes in an atmospheric firing furnace while 100 vol.% hydrogen was passed through at 300 ml / min. The boat was then held at 1000°C for 5 hours and then naturally cooled to room temperature to obtain a powder of Comparative Example 3.

[0043] Comparative Example 4 Rutile-type titanium dioxide (manufactured by Sakai Chemical Industry Co., Ltd., product name "STR-100N", specific surface area 100 m 2 7.9 g of titanium dioxide (1 / g) and 2.1 g of titanium hydride (manufactured by Toho Tech Co., Ltd., trade name "Titanium hydride powder TCH-450") were dry-mixed, then placed in an alumina boat and heated to 1100°C over 107 minutes in an atmospheric firing furnace while 100 vol% hydrogen was passed through at 400 ml / min. The temperature was then maintained at 1100°C for 3 hours, and the mixture was then naturally cooled to room temperature to obtain a powder of Comparative Example 4.

[0044] Comparative Example 5 Barium titanate (manufactured by Sakai Chemical Industry Co., Ltd., product name "BT-01") was used.

[0045] Comparative Example 6 Iron oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "iron(III) oxide") was used.

[0046] Comparative Example 7 Carbon (manufactured by Cabot Corporation, trade name "VULCAN XC-72R") was used.

[0047] The materials of Examples 1 to 3 and Comparative Examples 1 to 7 were subjected to various measurements and evaluations using the following methods. The results are shown in Table 1. The results of electron microscope observation of the materials of Examples 1 to 3 and Comparative Examples 3 and 4 are shown in Figures 1 to 5. <Calculating the x value of titanium oxide composition formula TiOx> The x value in the composition formula of titanium oxide, TiOx, was calculated by measuring the change in weight before and after heat treatment according to the following procedure. A predetermined amount of titanium oxide powder to be measured was first dried in a dryer (Yamato Scientific Co., Ltd., constant temperature incubator, DKM600) at 100°C for 1 hour to remove adsorbed moisture. Approximately 1 g was then weighed into a magnetic crucible using an electronic balance (Shimadzu Corporation, analytical balance, ATX224). The powder was then heat-treated in an electric furnace (Nitto Scientific Co., Ltd., tabletop electric furnace, NHK-120H-II) at 900°C for 1 hour in an air atmosphere to convert it to a complete TiO2 (x = 2.00) state. After the heat treatment, the crucible was transferred to a glass desiccator and allowed to cool to room temperature before being reweighed. The weight increase before and after heat treatment corresponds to the amount of oxygen vacancies from TiO2. The formula of the titanium oxide before heat treatment was TiOx1, its weight was W1 (g), its weight after heat treatment was W2 (g), and the atomic weight of Ti was M. T , the atomic weight of O is M O When The number of moles of TiOx1 before heat treatment = W1 / (M T +x1M O ) Number of moles of TiO2 after heat treatment = W2 / (M T +2M O ) Since the number of moles of TiOx1 and TiO2 does not change before and after heat treatment, W1 / (M T +x1M O )=W2 / (M T +2M O ) Therefore, when we solve for x1, we get x1=(W1(M T +2M O )-W2M T ) / W2M O Using the above formula, x1 was calculated. Furthermore, in order to exclude the influence of the weight change due to heat treatment of the moisture adhering to titanium oxide to be measured before heat treatment, titanium oxide (manufactured by Sakai Chemical Industry Co., Ltd., trade name "STR-100N", specific surface area 100 m 2 / g) was prepared in advance using the powder heat-treated above as the standard powder. The standard powder was further heat-treated above, and the value of x1 in the composition formula TiOx1 of titanium oxide calculated from the weight increment before and after heat treatment was taken as x STD . Then, for the x1 values calculated by the above method for the powders of the examples and comparative examples, 2 / x STD was multiplied, and the resulting value was taken as the value of x in the composition formula TiOx of titanium oxide. Also, when the value after multiplying by 2 / x STD exceeded 2, it was regarded as the influence of excessively adhering moisture, and x = 2 was taken.

[0048] <Specific surface area (BET-SSA)> In accordance with the provisions of JIS Z8830 (2013), after heat-treating the sample in a nitrogen atmosphere at 200 °C for 60 minutes, the specific surface area (BET-SSA) was measured using a specific surface area measuring device (manufactured by Mountech Co., Ltd., trade name "Macsorb HM-1220"). <Particle size in terms of specific surface area> When the specific surface area (BET-SSA) is S and the density of the particles is ρ, the particle size in terms of specific surface area d can be calculated from the following formula. d = 6÷(ρ×S) From the above formula, assuming the density of titanium suboxide is 4.0 g / cm 3 , the particle size in terms of specific surface area of the titanium suboxide powders of the examples and comparative examples was calculated. <Average particle size> The average particle size of any 20 particles was measured from the electron microscope observation image. In the case of an aggregate where the particles were fused, the particle size of the aggregated particles was measured. <X-ray diffraction pattern> Under the following conditions, a powder X-ray diffraction pattern was measured using an X-ray diffractometer (manufactured by Rigaku Corporation, trade name "RINT-TTR3"). X-ray source: Cu-Kα ray Measurement range: 2θ = 10~70° Scan speed: 5° / min Voltage: 50 kV Current: 300mA

[0049] <Real part of complex relative permittivity and dielectric loss tangent at 1 GHz in powder state> The real part of the complex relative permittivity and the dielectric loss tangent of the powder were measured using a permittivity measuring device ADMS01Nc1 (manufactured by AET Corporation) and an attached 1 GHz resonator. <Volume resistivity (also called volume specific resistance)> The powder volume resistivity was measured using a powder resistivity measurement system, model MCP-PD51 (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), which consists of a hydraulic powder press, a four-point probe, and a high-resistivity measurement device (Loresta GX MCP-T700, manufactured by the same company). <L * a * b * Lightness L in the color system * value, chromaticity a * value, b * Value> Using a colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SE2000"), * a * b * Lightness L in the color system * value, chromaticity a * value, b * The values ​​were measured. <Electron microscope photograph observation> Observation was carried out using a field emission transmission electron microscope JEM-2100F (manufactured by JEOL Ltd.). <Volume resistivity (also called volume specific resistance)> The volume resistivity (Ω·cm) was determined according to the following procedure. 1) The sample powder was placed in a press jig (20 mm in diameter) equipped with a four-point probe on the bottom, and set in the pressurizing section of the powder resistance measurement system. 2) After the powder press section was pressurized to 20 kN, the powder thickness was measured with a digital caliper and the resistance value was measured with a high resistance measuring device. 3) The volume resistivity (Ω·cm) was calculated from the powder thickness and resistance value using the following formula. (Volume resistivity) = (Resistance value) x (Resistivity correction coefficient) x (Thickness)

[0050] <Radio wave heating rate, heat radiation rate> 0.5 g of each of the powders from the Examples and Comparative Examples was placed in an alumina crucible, and powder temperature 1 was measured using a radiation thermometer THI-300 (manufactured by Ichinen TASCO Corporation). Powder temperature 1 was then measured again using a single-function microwave oven IM-573 (manufactured by Iwatani Corporation) with 2.4 GHz electromagnetic waves at 600 W for 2 minutes, and powder temperature 2 was measured again. After allowing the powder to cool for another 2 minutes, powder temperature 3 was measured. The microwave heating rate and heat dissipation rate after microwave heating were calculated from the measured temperature and the following formula: (Radio heating rate [℃ / min])={(Powder temperature 2[℃])-(Powder temperature 1[℃])}÷2[min] (Heat release rate after radio wave heating [℃ / min])={(Powder temperature 2[℃])-(Powder temperature 3[℃])}÷2[min] <Light heating rate> 2 ml of each powder in the Examples and Comparative Examples was weighed out using a measuring cylinder and placed in an alumina crucible. The powder temperature 4 was measured using a radiation thermometer THI-300 (manufactured by Ichinen TASCO), and then a white LED light (MG-145R manufactured by Gentos) was irradiated onto the top of the powder for 5 minutes to measure the re-powdering temperature 5. The photoheating rate was calculated from the measured temperature and the following formula. (Light heating rate [℃ / min])={(Powder temperature 5[℃])-(Powder temperature 4[℃])}÷5[min] <Real part of complex relative permittivity and dielectric loss tangent at 10 GHz for resin molded body> 4.37 g of each powder of the Examples and Comparative Examples, 3.70 g of epoxy resin (Epicron 850 manufactured by DIC Corporation), 2.81 g of polyfunctional thiol epoxy resin curing agent (TMMP manufactured by SC Organic Chemicals), and 0.04 g of imidazole (Curesol 2E4MZ manufactured by Shikoku Chemical Industry Co., Ltd.) were placed in an ointment container and mixed using a stirring and degassing device (Awatori Rentaro ARE-310) at a rotation speed of 2000 rpm for 5 minutes and degassing at a rotation speed of 2200 rpm for 1 minute. The mixture was then poured into a Teflon (registered trademark) mold measuring 60 mm in length, 10 mm in width, and 1 mm in depth. The resin was then cured using a heated hydraulic press (Toyo Seiki Seisakusho, product name Mini Test Press MP-WNH) at a set pressure of 0.5 MPa at 100 °C for 1 hour to prepare a resin test piece for complex dielectric constant measurement. The real part of the complex relative permittivity and the dielectric loss tangent at 10 GHz were measured for the prepared resin test pieces using a permittivity measuring device ADMS01Nc1 (manufactured by AET Corporation) and an attached 10 GHz resonator.

[0051] [Table 1]

[0052] Furthermore, the materials of Example 1 and Comparative Example 7 were mixed with resin by the following method to produce resin moldings, which were then evaluated for their radio wave absorption properties. The evaluation method and results are as follows: <Radio wave absorption characteristics> 28.44 g of the powder of Example 1, or an amount equivalent to the bulk of the powder of Comparative Example 7, 10.00 g of epoxy resin (Epicron 850, manufactured by DIC Corporation), 7.6 g of a polyfunctional thiol epoxy resin curing agent (TMMP, manufactured by SC Organic Chemicals), and 0.1 g of imidazole (Curesol 2E4MZ, manufactured by Shikoku Chemicals Corporation) were placed in an ointment container, and the mixture was mixed using a stirring and degassing device (Awatori Rentaro ARE-310) at 2000 rpm for 5 minutes and then at 2200 rpm for 1 minute. The mixture was then poured into a mold measuring 100 mm long, 100 mm wide, and 1 mm deep. The resin was then cured using a heated hydraulic press (Mini Test Press MP-WNH, manufactured by Toyo Seiki Seisakusho, Ltd.) at a set pressure of 0.5 MPa at 100 °C for 1 hour to prepare a resin test piece for measuring electromagnetic heating and heat dissipation properties. The radio wave absorption characteristics of the fabricated specimens were measured at room temperature and 76 GHz using a PNA network analyzer N5227A (Keysight Technologies) by the free space method. The measured radio wave absorption properties were normalized with the value of Comparative Example 7 being 100. The test piece prepared using the powder of Example 1 had a radio wave absorption property of 104, confirming that it has excellent properties as an electromagnetic wave absorbing / emitting material.

[0053] As can be seen from the electron microscope observation results in Figures 1 to 3, the titanium suboxides of Examples 1 to 3 had little fusion between adjacent particles, and the ratio of average particle size to specific surface area converted particle size was 1.0 or less. As shown in Table 1, x in TiOx was a number of 1 ≤ x < 1.8, and the specific surface area was 5 m 2 The titanium suboxides of Examples 1 to 3, which had an average particle size / specific surface area converted particle size ratio of 0.5 to 3.0, exhibited a high heating rate when irradiated with electromagnetic waves using radio waves or light and a high heat dissipation rate after radio wave heating. On the other hand, Comparative Examples 1 and 2, which used titanium dioxide (TiO2) instead of titanium suboxide, and Comparative Example 3, which used titanium suboxide but with x in TiOx of less than 1.8 and a specific surface area of ​​5 m 2In Comparative Examples 3 and 4, in which the average particle size / specific surface area converted particle size was less than 3.0 / g and further in which the particles were fused together to form aggregates as shown in Figures 4 and 5, both the heating rate when irradiated with electromagnetic waves and the subsequent heat release rate were slower than those of the titanium oxides of Examples 1 to 3. Furthermore, the titanium suboxides of Examples 1 to 3 had a faster heating rate when irradiated with electromagnetic waves and a faster subsequent heat release rate than the barium titanate and iron oxide of Comparative Examples 5 and 6, which have traditionally been used as dielectric and magnetic materials. Furthermore, unlike the carbon of Comparative Example 7, no ignition was observed when irradiated with electromagnetic waves, and the subsequent heat release rate was also faster than that of Comparative Example 7. From these results, it is clear that x in TiOx is a number 1≦x<1.8 and the specific surface area is 5m 2 It was confirmed that titanium suboxide having a specific surface area of ​​0.5 to 3.0 and an average particle size / specific surface area converted particle size of 0.5 to 3.0 has excellent properties as an energy absorption / release material for electromagnetic waves, heat, and the like. Furthermore, when formed into a resin molded body, the titanium suboxides of Examples 1 to 3 were confirmed to have higher real parts of complex dielectric constant and dielectric loss tangent at 10 GHz, which affect the electromagnetic wave absorption characteristics, than the titanium oxides and barium titanates of Comparative Examples 1 to 5, which have traditionally been used as dielectric materials, and to have a higher real part of complex dielectric constant at 10 GHz than the carbon of Comparative Example 7, which has traditionally been used as an electromagnetic wave absorber. Furthermore, it was confirmed that the molded body obtained by mixing the titanium oxide of Example 1 with a resin had radio wave absorption characteristics equal to or better than those of a molded body obtained by mixing carbon and a resin.

Claims

1. It is expressed by the composition formula TiOx (x represents a number 1≦x<1.8) and has a specific surface area of ​​5m ２ / g or more and having an average particle size / specific surface area converted particle size ratio of 0.8 to 1.

2.

2. The real part of the complex relative permittivity at a frequency of 1 GHz is 25 or more, and the dielectric loss tangent is 2.6 x 10 －２ 2. The energy absorption / release material according to claim 1, wherein the energy absorption / release material is as described above.

3. 3. The energy absorption / release material according to claim 1, wherein the energy to be absorbed is electromagnetic waves.

4. A resin material comprising the energy absorbing / releasing material according to any one of claims 1 to 3 and a resin.

5. A fiber material comprising the energy absorbing / releasing material according to any one of claims 1 to 3 and organic and / or inorganic fibers.

6. A ceramic material comprising the energy absorption / release material according to any one of claims 1 to 3 and ceramics.

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