TW202248137A - Particle group, composition, molded article, and particle group production method - Google Patents

Abstract

According to the present invention, a particle group contains a group of particles containing crystal, and meets requirement 1 and at least one of requirements 2 and 3. Requirement 1: |dA(T)/dT| is 10 ppm/DEG C or more at least one temperature T1 in the range of -200 to 1200 DEG C, where A represents (lattice constant of a-axis (minor axis) of crystal)/(lattice constant of c-axis (major axis) of crystal), and each of the lattice constants is obtained by X-ray diffraction measurement of the particle group. Requirement 2: SBET/SPSD is 4.0-20.0, where SBET represents the specific surface area of the particle group as determined by BET method. SPSD represents the specific surface area of a virtual particle group, the virtual particle group has the same volume-based particle size distribution as that of the particle group obtained by a laser diffraction scattering method, and the same true density as that of the particle group, and each virtual particle has a true sphere shape. Requirement 3: a porosity is 2.0-20.0%, where the porosity (%) = (1 - apparent density of particle group/true density of particle group) * 100.

Description

Particle group, composition, molded body, and method for producing particle group

The present invention relates to a particle group, a composition, a molded body, and a method for producing the particle group.

Previously, it is known to add a filler having a smaller thermal expansion coefficient to the solid material to reduce the thermal linear expansion coefficient of the solid material.

For example, Patent Document 1 discloses tungsten-zirconium phosphate as a filler with a negative thermal expansion coefficient. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2018-2577

[Problem to be solved by the invention]

However, the prior materials may not be able to sufficiently reduce the coefficient of thermal expansion.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a particle group capable of exhibiting excellent control characteristics of a thermal linear expansion coefficient, a composition, a molded article, and a production method using the same. [Technical means to solve the problem]

The present inventors arrived at the present invention through various studies. That is, the present invention provides the following inventors.

One aspect of the present invention is a particle group in which each particle contains a plurality of crystals, and the particle group satisfies the following requirement 1 and at least one of the following requirements 2 and 3. Requirement 1: At least one temperature T1 among -200°C to 1200°C, |dA(T)/dT| is 10 ppm/°C or more. A is (lattice constant of the a-axis (short axis) of the above-mentioned crystal)/(lattice constant of the c-axis (long axis) of the above-mentioned crystal), and each of the above-mentioned lattice constants is determined by X-ray diffraction of the above-mentioned particle group acquired. Requirement 2: S _BET /S _PSD is 4.0 to 20.0. S _BET is the specific surface area of the above particle group obtained by the BET method. S _PSD is the specific surface area of a virtual particle group that has the same particle size distribution as the volume-based particle size distribution of the above-mentioned particle group obtained by the laser diffraction scattering method, and the true density of the above-mentioned particle group The same true density, and the shape of each imaginary particle is a true sphere. Requirement 3: The porosity defined by the following formula is 2.0 to 20.0%. Porosity (%)=(1-apparent density of particle group/true density of particle group)×100

The above-mentioned particle group can satisfy all of the above-mentioned requirements 1 to 3.

In the above-mentioned particle group, the particle diameter D50 at which the cumulative frequency reaches 50% in the volume-based cumulative particle size distribution curve of the above-mentioned particle group obtained by the laser diffraction scattering method may be 1 to 100 μm.

The aforementioned crystals may be metal oxides.

The aforementioned metal oxide may be a metal oxide containing a metal having d electrons.

The aforementioned metal oxide may be a metal oxide containing titanium.

The aforementioned metal oxide containing titanium may be TiO _x (x=1.30˜1.66).

The composition of one aspect of the present invention contains any one of the particle groups described above.

The above composition may have a powder form.

The composition described above may in turn comprise a matrix material.

The above-mentioned composition may further contain an uncured curable resin.

A molding system of an aspect of the present invention is a molding of the above-mentioned particle group or a composition having a powder form.

The method of one aspect of the present invention is a method for producing any one of the above-mentioned particle groups, which includes: step 1, calcination of raw materials to obtain intermediates; step 2, pulverization of the above-mentioned intermediates to obtain precursors; and step 3, calcination of the above-mentioned precursors material, and the calcination temperature in the above step 1 and step 3 is 1000-1300°C.

The above method may include the step of granulating the precursor by a spray drying method between step 2 and step 3 to obtain the granular precursor. [Effect of Invention]

According to the present invention, it is possible to provide a particle group capable of exhibiting an excellent control characteristic of a thermal linear expansion coefficient, and various compositions and molded articles using the same. Also, according to the present invention, it is possible to provide a method for producing a particle group capable of exhibiting excellent control characteristics of thermal linear expansion coefficient.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

＜Particle Swarm P＞ The particle group P includes a plurality of particles. Each particle contains a plurality of crystals, and each particle can be an aggregate of a plurality of crystals. Each particle may be a secondary particle in which a single crystal is used as the primary particle, or a secondary particle in which an aggregate of a plurality of crystals is used as the primary particle.

The particle group P satisfies the following requirement 1, and further satisfies at least one of the following requirements 2 and 3. The particle group P preferably satisfies all of the following requirements 1 to 3. Requirement 1: At least one temperature T1 among -200°C to 1200°C, |dA(T)/dT| is 10 ppm/°C or more. A is (lattice constant of the a-axis (short axis) of the above-mentioned crystal)/(lattice constant of the c-axis (long axis) of the above-mentioned crystal), and each lattice constant is determined by the X-ray diffraction measurement of the particle group P get.

Requirement 2: S _BET /S _PSD is 4.0 to 20.0. S _BET is the specific surface area of the particle group P obtained by the BET method. S _PSD is the specific surface area of the virtual particle group V. The virtual particle group V has the same particle size distribution as the particle size distribution based on the volume of the particle group P obtained by the laser diffraction scattering method, and the same true density as the true density of the above-mentioned particle group, and each virtual particle The shape is a true sphere.

Requirement 3: The porosity defined by the following formula is 2.0 to 20.0%. Porosity (%)=(1-apparent density of particle group P/true density of particle group P)×100

(requirement 1) Requirement 1 will be described in detail. The lattice constant in the definition of A is specified by the powder X-ray diffraction measurement of the particle group P. As an analysis method, there is the Rietveld method, or an analysis by fitting based on the least squares method.

In this specification, in the crystal structure of the particle group P specified by powder X-ray diffraction measurement, the axis corresponding to the smallest lattice constant is set as the a-axis, and the axis corresponding to the largest lattice constant is The axis is set to the c-axis. Let the length of the a-axis and the length of the c-axis of the crystal lattice be the length of the a-axis and the length of the c-axis, respectively.

A(T) is a parameter representing the anisotropy of the length of the crystal axis, and is a function of temperature T (unit °C). The larger the value of A(T), the larger the length of the a-axis relative to the length of the c-axis, and the smaller the value of A, the smaller the length of the a-axis relative to the length of the c-axis.

Here, |dA(T)/dT| represents the absolute value of dA(T)/dT, and dA(T)/dT represents the differential of T (temperature) of A(T). However, in this specification, |dA(T)/dT| is defined by the following formula (1). ｜dA(T)/dT｜＝｜A(T＋50)－A(T)｜/50...(1)

As described above, the crystals in the particle group P of this embodiment need to satisfy |dA(T)/dT| of 10 ppm/°C or higher at at least one temperature T1 of -200°C to 1200°C. Here, |dA(T)/dT| is defined within the range where the crystal exists in a solid state. Therefore, the highest temperature of T in formula (1) is a temperature 50° C. lower than the melting point of crystals (particles). That is, when the limitation of "at least one temperature T1 among -200°C to 1200°C" is added, the temperature range of T in the formula (1) is -200 to 1150°C.

At least one temperature T1 of -200°C to 1200°C, |dA(T)/dT| is preferably 20 ppm/°C or higher, more preferably 30 ppm/°C or higher. The upper limit of |dA(T)/dT| is preferably at most 1000 ppm/°C, more preferably at most 500 ppm/°C.

A value of |dA(T)/dT| above 10 ppm/°C at at least one temperature T1 means that the anisotropy of the crystal structure varies greatly with temperature changes.

At at least one temperature T1, dA(T)/dT can be positive or negative, but preferably negative.

Depending on the type of crystal, the crystal structure may change due to structural phase transition within a certain temperature range. In this specification, in the crystal structure at a certain temperature, the axis corresponding to the minimum lattice constant is set as the a-axis, and the axis corresponding to the maximum lattice constant is set as the c-axis. In any crystal system of triclinic, monoclinic, rectangular, tetragonal, hexagonal, or rhombohedral, the a-axis and c-axis are as defined above.

If the crystal satisfies Requirement 1, it is easy to lower the coefficient of thermal expansion in the composition containing the particle group P and in the molded article.

(Requirement 2) Next, Requirement 2 will be described. S _BET /S _PSD represents the complexity of each particle shape of the particle group P, and takes a value of 1 or more. S _BET is the specific surface area of the particle group P obtained by the BET method. In addition, in this specification, a specific surface area means the value obtained by dividing the surface area of a sample by the mass of a sample.

The method of measuring the BET specific surface area is shown below. The particle group P was dried at 200° C. for 30 minutes in a nitrogen atmosphere as a pretreatment. The BET flow method was used for the measurement of the specific surface area. A mixture of nitrogen and helium is used as the adsorption gas. The ratio of nitrogen in the mixed gas was set to 30% by volume, and the ratio of helium in the mixed gas was set to 70% by volume. As a measuring device, for example, a BET specific surface area measuring device Macsorb HM-1201 (manufactured by Mountech) can be used.

S _PSD is the specific surface area of the virtual particle group V. The virtual particle group V has the same particle size distribution as the particle size distribution based on the volume of the particle group P obtained by the laser diffraction scattering method, and the same true density as the true density of the above-mentioned particle group, and each virtual particle The shape is a true sphere.

The method of measuring the particle size distribution curve of the particle group P accumulated based on the volume of the laser diffraction scattering method is shown below.

The pretreatment was diluted by adding 99 parts by weight of water to 1 part by weight of the particle group P, and subjected to ultrasonic treatment with an ultrasonic cleaner. Ultrasonic treatment time was set at 10 minutes. As an ultrasonic cleaning machine, NS200-6U manufactured by Nippon Seiki Manufacturing Co., Ltd. can be used. As the frequency of ultrasonic waves, it can be set to about 28 kHz.

The particle size distribution of the volume-based particle group P is measured by the laser diffraction scattering method. For example, a laser diffraction particle size distribution analyzer Mastersizer 2000 manufactured by Malvern Instruments Ltd. can be used.

When the crystal is Ti ₂ O ₃ , the refractive index of Ti ₂ O ₃ can be measured as 2.40.

It is considered that the closer S _BET /S _PSD is to 1, the closer the particle shape of particle group P is to a true sphere, and the larger S _BET /S _PSD is, the more complex the particle shape of particle group P is.

As described above, in the particle group P of this embodiment, S _BET /S _PSD needs to be 4.0 or more and 20.0 or less. S _BET /S _PSD is preferably at least 4.3, more preferably at least 4.5. S _BET /S _PSD can be 5.0 or more, 6.0 or more, 7.0 or more, 8.0 or more, 9.0 or more, or 10.0 or more. S _BET /S _PSD is preferably at most 16.0, more preferably at most 15.0. S _BET /S _PSD can be below 14.0, below 13.0 or below 12.0.

If the particle group P satisfies Requirement 2, the thermal linear expansion coefficient is likely to be lowered in the composition and molded article containing the particle group P.

(Requirement 3) Next, requirement 3 will be described. Requirement 3 stipulates that the porosity defined by the following formula is 2.0 to 20.0%. Porosity (%)=(1-apparent density of particle group P/true density of particle group P)×100

The apparent density of the particle group P refers to the value obtained by dividing the mass of the particle group P by the sum of the volume of the solid constituting the particle group P and the volume of closed pores in the solid constituting the particle group P. In other words, the apparent density of the particle group P means that the volume obtained by adding the volume occupied by the solid to the volume of the closed pores is used as the density of the volume for density calculation. The larger the volume of the closed pores, the smaller the value of the apparent density. When there are no closed pores, the apparent density is equal to the true density.

The true density of the particle group P is obtained by dividing the mass of the particle group P by the volume of the solid constituting the particle group P. In other words, the true density of the particle group P means the density in which only the volume occupied by the solid portion is used as the volume for density calculation. The true density does not depend on the shape of the particle, it is an inherent value of matter.

The closed pores in the particle group P exist in the space inside the solid constituting the particle group P. This space is usually a space not filled with other materials in the composition to which the particle group P is added, the molded article, etc. mentioned later, and contributes to reducing the thermal expansion rate. The closed pores may be spaces formed in crystals or spaces formed between crystals. For example, when the particles are polycrystalline particles in which a large number of crystals are randomly arranged within the particles, the particles may have closed pores between the crystals.

FIG. 1 is a schematic cross-sectional view of an example of particles of the particle group P according to this embodiment. The particle 4 is an aggregate having a plurality of crystals 2 , and the particle 4 has closed pores 6 arranged between the crystals 2 .

The porosity defined by the above formula means the ratio of the total volume of closed pores present in the particle group P to the apparent volume of the particle group P. Furthermore, the apparent volume of the particle group P refers to the sum of the volume of the solid constituting the particle group P and the volume of closed pores in the solid constituting the particle group P.

As mentioned above, in the particle|grains of this embodiment, the said porosity needs to be 2.0 % or more and 20 % or less. The porosity is preferably at least 2.3%, more preferably at least 2.5%. The porosity may be 2.7% or more, 2.8% or more, 2.9% or more, 3.0% or more, 3.2% or more, 3.5% or more, 3.7% or more, or 4.0% or more. The porosity is preferably at most 16%, more preferably at most 14%. The porosity may be 13.0% or less, 12.0% or less, 11.0% or less, 10.0% or less, 9.0% or less, 8.0% or less, 7.0% or less, 6.0% or less, or 5.0% or less.

If the particles satisfy Requirement 3, the coefficient of thermal expansion is likely to be lowered in a composition containing the particle group P, etc., and in a molded article.

In this specification, in the cumulative particle size distribution curve based on the volume of the particle group P, the cumulative frequency is calculated from the smaller particle size, and the particle size when the cumulative frequency reaches 50% is set as D50.

From the viewpoint of ensuring the fluidity of the liquid composition added with the particle group P, D50 is preferably at least 1 μm, more preferably at least 3 μm, further preferably at least 5 μm, and most preferably at least 7 μm. From the viewpoint of ensuring the ease of penetration into narrow gaps of the liquid composition added with the particle group P, D50 is preferably 100 μm or less, more preferably 80 μm or less, further preferably 60 μm or less. D50 may be 50 μm or less, 40 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less.

The crystal is preferably an oxide. In particular, the crystal is more preferably a metal oxide. Metal oxides may contain a plurality of metals.

The metal oxide is not particularly limited, but is preferably a metal oxide containing a metal having d electrons, more preferably a metal oxide containing a metal having only 3d electrons among d electrons.

The metal oxide containing a metal having d electrons is not particularly limited, and examples include metal oxides containing Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, and Mo. thing.

Examples of the metal oxide containing a metal having only 3d electrons among d electrons include metal oxides containing Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu. Among them, metal oxides containing titanium are preferable from the viewpoint of resource availability.

More specifically, the metal oxide containing titanium is preferably represented by the composition formula TiO _x (x=1.30-1.66), and more preferably represented by the composition formula TiO _x (x=1.40-1.60). In _TiOx , a part of Ti atoms may be replaced by other elements.

Furthermore, the metal oxide containing titanium may be an oxide containing titanium and metal atoms other than titanium, such as LaTiO ₃ , in addition to TiO _x .

As the crystal structure of the above-mentioned crystal, it is preferable to have a perovskite structure or a corundum structure, and it is more preferable to have a corundum structure.

Although it does not specifically limit as a crystal system, Rhombohedral crystal system is preferable. As a space group, it is preferably assigned to R-3c.

<Manufacturing method of particle group P> Next, an example of a method for producing the above-mentioned particle group P will be described. The method for producing particle group P according to this embodiment includes step 1 of calcining raw materials to obtain intermediates, step 2 of pulverizing the intermediates to obtain precursors, and step 3 of calcining the precursors. The calcination temperature is not less than 1000°C and not more than 1300°C.

step 1 The raw material refers to a substance that can be converted into the above-mentioned crystals through subsequent steps. The type of raw material is not particularly limited, and may be a single substance or a mixture. For example, when the crystal of the particle group P to be produced is a metal oxide containing titanium, the raw material may be a mixture of metal titanium and titanium oxide.

Calcination of raw materials is preferably carried out in an electric furnace. Examples of electric furnace structures include box type, crucible type, tubular type, continuous type, bottom lift type, rotary kiln, platform type, etc. As a box-type electric furnace, there exists FD-40*40*60-1Z4-18TMP (made by NEMS Co., Ltd.), for example. Examples of tubular electric furnaces include PCR (manufactured by MOTOYAMA Co., Ltd.) and DSPSH28 (manufactured by MOTOYAMA Co., Ltd.). In step 1, all the raw materials can be converted into the above-mentioned crystals, or only a part of the raw materials can be converted into the above-mentioned crystals. In other words, as long as the obtained intermediate contains the crystals in the above-mentioned particle group P, unreacted raw materials may or may not be contained.

step 2 The method of pulverizing the intermediate obtained in Step 1 is not particularly limited, and examples include a method of pulverizing the pulverized product in a mortar with a pestle, and a method of pulverizing with a ball mill or bead mill. The crushing can be dry crushing or wet crushing. By appropriately changing the crushing conditions, such as the intensity of the applied force and the time for performing the crushing, the average particle diameter of the particle group of the obtained precursor can be adjusted.

Between the above step 2 and step 3, a step of granulating the pulverized precursor by spray drying to obtain the granular precursor may be further included.

step 3 The calcination of the precursor can be carried out by the same method as the calcination in step 1.

As mentioned above, the calcination temperature in step 1 and step 3 is not less than 1000°C and not more than 1300°C. From the viewpoint of improving the crystallinity in the particle group P, the firing temperature may be, for example, 1025°C or higher, 1040°C or higher, or 1050°C or higher. From the viewpoint of preventing the increase of the crystal particle size and each particle size of the particle group, the calcination temperature may be, for example, 1275°C or lower, 1260°C or lower, or 1250°C or lower. The calcination temperature in step 1 and the calcination temperature in step 3 can be the same or different.

When the calcination temperature is in the above-mentioned range, it tends to be easy to control the S _BET /S _PSD of the particle group and the above-mentioned porosity. As a result, it is easy to produce a particle group that can exhibit excellent thermal expansion control characteristics.

<Composition containing particle group P> <First composition (powder composition for filler)> One embodiment of the present invention is a powder composition containing the above-mentioned particle group P and other powders. Such a powder composition can be suitably used as a filler for controlling the coefficient of thermal expansion of a solid composition described later. The content of the particle group P in the powder composition is not limited, and the function of controlling the amount of thermal expansion can be exerted according to the content. From the viewpoint of efficiently controlling the amount of thermal expansion, the content of the particle group P may be 75% by mass or more, 85% by mass or more, or 95% by mass or more.

Examples of powders other than particle group P in the powder composition are calcium carbonate, talc, mica, silicon oxide, clay, wollastonite, potassium titanate, xonotlite, gypsum fiber, aluminum borate, aromatic Polyamide fiber, carbon fiber, glass fiber, glass flake, polyoxybenzoyl whisker, glass balloon, carbon black, graphite, alumina, aluminum nitride, boron nitride, beryllium oxide, ferrite, iron oxide, Barium titanate, lead zirconate titanate, zeolite, iron powder, aluminum powder, barium sulfate, zinc borate, red phosphorus, magnesium oxide, aluminum magnesium carbonate, antimony oxide, aluminum hydroxide, magnesium hydroxide, zinc carbonate, TiO ₂ , TiO.

The D50 of the powder composition can be set in the same manner as the D50 of the above-mentioned particles.

The method for producing the powder composition is not particularly limited. For example, the above-mentioned particle group P is mixed with other powders, and the particle size distribution can be adjusted by crushing, sieving, pulverizing, etc. as necessary.

＜Second composition (solid composition)＞ The solid composition of the present embodiment includes a matrix material and the particle group P mentioned above.

[Matrix material] The base material is not particularly limited, and examples thereof include resins, alkali metal silicates, ceramics, and metals. The matrix material may maintain the above-mentioned particle group P in a solid state at normal temperature (20° C.).

Examples of resins are thermoplastic resins and cured products of thermal or active energy ray curable resins.

Examples of thermoplastic resins are polyolefins (polyethylene, polypropylene, etc.), ABS (Acrylonitrile-Butadiene-Styrene, acrylonitrile-butadiene-styrene) resins, polyamides (nylon 6, nylon 6,6, etc.), Polyamide imide, polyester (polyethylene terephthalate, polyethylene naphthalate), liquid crystal polymer, polyphenylene oxide, polyacetal, polycarbonate, polyphenylene sulfide, poly imide, polyetherimide, polyethersulfone, polyketone, polystyrene, and polyetheretherketone.

Examples of thermosetting resins are epoxy resins, oxetane resins, unsaturated polyester resins, alkyd resins, phenolic resins (phenolic resins, resole resins, etc.), acrylic resins, and urethane resins. , silicone resin, polyimide resin, and melamine resin, etc. Examples of active energy ray curable resins include ultraviolet curable resins and electron beam curable resins, such as urethane acrylate resins, epoxy acrylate resins, acrylic acrylate resins, polyester acrylate resins, phenolic acrylate resin. Other examples of resins include adhesives such as silicone-based, urethane-based, rubber-based, and acrylic-based.

A matrix material may contain 1 type of said resin, and may contain 2 or more types.

From the standpoint of improving heat resistance, the base material is preferably epoxy resin, polyethersulfone, liquid crystal polymer, polyimide, polyamideimide, or silicone.

Examples of the alkali metal silicate include lithium silicate, sodium silicate, and potassium silicate. The first material may contain one type of alkali metal silicate, or may contain two or more types. Such materials are preferable because of their high heat resistance.

The ceramics are not particularly limited, and examples include alumina, silicon oxide (including silicon oxide, silica glass), titanium oxide, zirconium oxide, magnesium oxide, cerium oxide, yttrium oxide, zinc oxide, and iron oxide. Material-based ceramics; silicon nitride, titanium nitride, boron nitride and other nitride-based ceramics; silicon carbide, calcium carbonate, aluminum sulfate, barium sulfate, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolin, polyhydrate Kaolin, pyrophyllite, montmorillonite, sericite, mica, magnesium chlorite, bentonite, asbestos, zeolite, calcium silicate, magnesium silicate, diatomaceous earth, quartz sand and other ceramics. The 1st material may contain 1 type of ceramics, and may contain 2 or more types. Ceramics are preferable because they improve heat resistance. A sintered body can be produced by discharge plasma sintering or the like.

The metal is not particularly limited, and examples include aluminum, tantalum, niobium, titanium, molybdenum, iron, nickel, cobalt, chromium, copper, silver, gold, platinum, lead, tin, tungsten and other simple metals, stainless steel (SUS) Such alloys, and such mixtures. The first material may contain one type of metal, or may contain two or more types. Such metals are preferable because they improve heat resistance.

[other ingredients] The solid composition may contain other components than the matrix material and the above-mentioned particle group P. As this component, a catalyst is mentioned, for example. It does not specifically limit as a catalyst, An acidic compound, a basic compound, an organometallic compound etc. are mentioned. As the acidic compound, acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphoric acid, formic acid, acetic acid, and oxalic acid can be used. As the basic compound, ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, or the like can be used. As an organometallic compound, the compound containing aluminum, zirconium, tin, titanium, or zinc, etc. are mentioned. In addition, powders other than the particle group P exemplified in the first composition (powder composition) may be contained.

The content of the above-mentioned particle group P in the solid composition is not particularly limited, and the function of controlling thermal expansion can be exerted according to the content. The content of the particle group P in the solid composition may be, for example, 1% by weight or more, 3% by weight or more, 5% by weight or more, 10% by weight or more, 20% by weight or more, or 40% by weight or more, or 70% by weight or more. When the content of the above-mentioned particle group P becomes high, the effect of reducing the coefficient of thermal linear expansion is likely to be exhibited. The content of the particle group P in the solid composition can be, for example, 99% by weight or less. The content of the above-mentioned particle group P in the solid composition may be 95% by weight or less, or may be 90% by weight or less.

The content of the matrix material in the solid composition can be, for example, 1% by weight or more. The content of the matrix material in the solid composition may be more than 5% by weight, or more than 10% by weight. The content of the matrix material in the solid composition can be, for example, 99% by weight or less. The content of the matrix material in the solid composition may be less than 97% by weight, less than 95% by weight, less than 90% by weight, less than 80% by weight, less than 60% by weight, or less than 30% by weight the following.

Since the solid composition of the present embodiment contains the above-mentioned particle group P, the thermal linear expansion coefficient of the solid composition can be reduced compared to the case where the particle group P is not added. Therefore, according to this solid composition, it is possible to obtain a member with little dimensional change when the temperature changes. Therefore, it can be suitably used for optical members and members for semiconductor manufacturing equipment that are particularly sensitive to dimensional changes due to temperature.

＜The third composition (liquid composition)＞ The liquid composition of the present embodiment includes the above-mentioned particle group P and a liquid material. The liquid composition of this embodiment is a fluid composition at 25°C. The liquid composition can be a raw material for the above-mentioned solid composition. "Having fluidity at 25°C" means that after supplying the composition into a predetermined container and making the liquid level level, the container is tilted at 45 degrees, and the liquid level moves or deforms one hour later.

[Liquid Material] The liquid material is in a liquid state and may be capable of dispersing the particle group P described above. The liquid material can be the raw material of the matrix material.

For example, when the matrix material is an alkali metal silicate, the liquid material may include the alkali metal silicate and a solvent capable of dissolving or dispersing the alkali metal silicate. When the matrix material is a thermoplastic resin, the liquid material may include a thermoplastic resin and a solvent capable of dissolving or dispersing the thermoplastic resin. In the case where the base material is a cured product of heat or active energy ray curable resin, the liquid material is heat or active energy ray curable resin before hardening.

The thermosetting resin before hardening has fluidity at room temperature, and will harden due to cross-linking reaction when heated. The thermosetting resin before hardening may contain 1 type of resin, and may contain 2 or more types.

Active energy ray-curable resins before curing have fluidity at room temperature, and are cured by irradiating active energy rays such as light (UV (Ultraviolet, ultraviolet rays) etc.) or electron beams to cause cross-linking reactions. The active energy ray-curable resin before curing contains a curable monomer and/or a curable oligomer, and may further contain a solvent and/or a photoinitiator as necessary. Examples of curable monomers and curable oligomers are photocurable monomers and photocurable oligomers. Examples of photocurable monomers are monofunctional or polyfunctional acrylate monomers. Examples of photocurable oligomers are urethane acrylate, epoxy acrylate, acrylate acrylate, polyester acrylate, phenol methacrylate.

Examples of the solvent include organic solvents such as alcohol solvents, ether solvents, ketone solvents, glycol solvents, hydrocarbon solvents, aprotic polar solvents, and water. Moreover, the solvent in the case of an alkali metal silicate is water, for example.

[other ingredients] The liquid composition of this embodiment may contain other components other than the liquid material and the particle group P mentioned above. For example, powders other than the particle group P mentioned in the first composition (powder composition) may be included.

The content of the particle group P in the liquid composition of the present embodiment is not particularly limited, and may be appropriately set from the viewpoint of controlling the coefficient of thermal expansion in the solid composition after hardening. Specifically, it may be the same as the content of the particle group P in the second composition (solid composition).

<Manufacturing method of liquid composition> The production method of the liquid composition is not particularly limited. For example, a liquid composition can be obtained by stirring and mixing the above-mentioned particle group P or powder composition with a liquid material. As a stirring method, the stirring mixing by a mixer is mentioned, for example. Alternatively, the particle group P and the like can be dispersed in the liquid material by ultrasonic treatment.

As a mixing method that can be used in the mixing step, for example, ball mill method, self-rotation-revolution mixer, impeller rotation method, blade rotation method, rotary film method, rotor/stator type mixer method, colloid mill method, high-pressure homogenizer method, ultrasonic dispersion method. In the mixing step, multiple mixing methods may be performed sequentially, or multiple mixing methods may be performed simultaneously. By homogenizing the composition while applying shear during the mixing step, the flowability and deformability of the composition can be improved.

<Manufacturing method of solid composition> After the liquid composition is shaped into the desired shape, the liquid material in the liquid composition is converted into a matrix material, so that a solid composition composed of the above-mentioned particle group P or powder composition and matrix material can be produced. thing.

For example, when the liquid material includes an alkali metal silicate and a solvent capable of dissolving or dispersing the alkali metal silicate, and a case of including a thermoplastic resin and a solvent capable of dissolving or dispersing the thermoplastic resin, by combining the liquid After the object is formed into a desired shape, the solvent is removed from the liquid composition to obtain a solid composition comprising the above-mentioned particle group and a matrix material (alkali metal salt or thermoplastic resin).

As a method for removing the solvent, a method of evaporating the solvent by natural drying, vacuum drying, heating, or the like can be applied. From the viewpoint of suppressing the generation of coarse bubbles, it is preferable to remove the solvent while maintaining the temperature of the mixture below the boiling point of the solvent when removing the solvent.

When the liquid material is heat or active energy ray hardening type resin before hardening, after forming the liquid composition into a desired shape, harden the liquid composition by heat or active energy rays (UV, etc.) .

Examples of methods for forming a liquid composition into a predetermined shape are as follows: injecting into a mold; and coating on the surface of a substrate to form a film shape.

Also, when the base material is ceramic or metal, it can be carried out as follows. A mixture of the raw material powder of the matrix material and the above-mentioned particle group P, etc. is prepared, and the mixture is heat-treated to sinter the raw material powder of the matrix material, whereby a solid composition comprising the matrix material as a sintered body and the above-mentioned particle group P, etc. can be obtained. If necessary, the pores of the solid composition can be adjusted by heat treatment such as annealing. As the sintering method, methods such as general heating, hot pressing, and discharge plasma sintering can be used.

Discharge plasma sintering refers to pressurizing the mixture of the raw material powder of the matrix material and the above-mentioned particle group P, etc., and passing a pulse-like current to the mixture. Thereby, electric discharge is generated between the raw material powder of the matrix material, and the raw material powder of the matrix material can be heated and sintered.

In order to prevent the obtained compound from deteriorating due to contact with air, the plasma sintering step is preferably performed under an inert gas such as argon, nitrogen, or vacuum.

The applied pressure in the plasma sintering step is preferably within a range of more than 0 MPa and not more than 100 MPa. In order to obtain a high-density first material, the pressurized pressure in the plasma sintering step is preferably set at 10 MPa or above, more preferably at 30 MPa or above.

The heating temperature in the plasma sintering step is preferably sufficiently lower than the melting point of the target host material.

Furthermore, the size and distribution of fine pores can be adjusted by heat-treating the obtained solid composition.

<Molded body of particle group P or powder composition> The molding system of this embodiment is a molded body of the particle group P or powder composition described above. The molded body in this embodiment may be a sintered body obtained by sintering the above-mentioned particle group P or powder composition.

Usually, a molded body is obtained by sintering the above-mentioned particle group P or powder composition. In this case, it is preferable to perform sintering within a temperature range in which the crystal structure in the particle group P can be maintained.

Various known sintering methods can be applied to obtain a sintered body. As a method for obtaining a sintered body, common methods such as heating, hot pressing, and discharge plasma sintering can be used.

Furthermore, the molded body of this embodiment is not limited to a sintered body, and may be, for example, a pressurized powder obtained by press-molding the above-mentioned particle group P or powder composition.

According to the molded body of the above-mentioned particle group P or powder composition of this embodiment, a member with less thermal expansion can be provided, and the dimensional change of the member when the temperature changes can be minimized. Therefore, it can be suitably used for various members used in devices that are particularly sensitive to dimensional changes due to temperature. Therefore, it can be suitably used for optical members and members for semiconductor manufacturing equipment that are particularly sensitive to dimensional changes due to temperature.

Next, specific usage forms of the above-mentioned solid composition and molded body will be described. The solid composition and molded article of the above-mentioned embodiment are excellent in electrical insulation, so they can be used as components for electronic devices, mechanical components, containers, optical components, and adhesives.

[Components for electronic devices] Examples of members for electronic devices include sealing members, conductive adhesives, circuit boards, prepregs, and insulating sheets.

Examples of sealing members are sealing members for semiconductor elements, underfill members, and interchip fillers for 3D-LSI (three-dimensional large-scale integration). Examples of semiconductor elements include power semiconductors such as power transistors and power ICs (Integrated Circuits), and light emitting elements such as LEDs (Light Emitting Diodes, light emitting diodes). According to the sealing member using the above solid composition and molded body, cracks due to differences in thermal expansion coefficients can be suppressed.

Examples of the conductive adhesive are anisotropic conductive film and anisotropic conductive paste. By including the particles of the present embodiment in the conductive adhesive, thermal expansion of the adhesive member can be reduced, problems of cracks and warpage in the contact portion of different materials can be eliminated, and electrical insulation can be improved.

The circuit substrate has a metal layer and an electrical insulating layer arranged on the metal layer. By using the above-mentioned solid composition and molded body on the electrical insulation layer, the coefficient of thermal expansion can be reduced while maintaining electrical insulation, and the difference between the thermal expansion coefficient and the metal layer can be reduced, thereby eliminating problems such as warping and cracks . As a specific example of a circuit board, a printed circuit board, a multilayer printed wiring board, a buildup board, a capacitor built-in board, etc. are mentioned.

A prepreg is a semi-hardened material impregnated with a base material comprising a reinforcing base material and a matrix material impregnated in the reinforcing base material. By making the prepreg contain the particles of this embodiment, the cured prepreg can exhibit high dimensional stability even in an environment where a thermal load is applied.

An example of the insulating sheet is a resin sheet such as polyvinyl chloride. By making the insulating sheet contain the above-mentioned particles, electrical insulation can be maintained and dimensional accuracy can be improved.

[Mechanical components] Mechanical components refer to the components that constitute various mechanical devices. Examples of mechanical devices include machine tools such as cutting devices, processing devices, and semiconductor manufacturing devices. Examples of mechanical components are fixed mechanisms, moving mechanisms, tools, and the like. According to the heat dissipation member using the above-mentioned solid composition and molded body, dimensional deviation due to thermal expansion can be suppressed, and precision such as working precision and machining precision can be improved. In addition, it is also suitable for use in joints between members made of different materials.

Also, the mechanical member may be a rotating member. A rotating member refers to a member that rotates while interacting with other members, such as a gear. In a rotating member, if the size changes due to thermal expansion, problems such as meshing failure and wear will occur, so the above-mentioned solid composition and molded body are preferably used.

Also, the mechanical component may be a substrate. In the substrate, if the size changes due to thermal expansion, there will be problems such as dislocation, so the above-mentioned solid composition and molded body are preferably used.

[container] A container refers to a component used to contain gas, liquid, solid, etc. An example of a container is, for example, a mold for making a molded body. For example, if the size of the mold changes due to thermal expansion, there will be problems such as the dimensional accuracy of the molded body cannot be guaranteed, so the above-mentioned solid composition and molded body are suitable for use.

[Optical components] Examples of optical components are optical fibers, optical waveguides, lenses, mirrors, filters, optical filters, diffraction gratings, fiber gratings, and wavelength conversion components. Examples of the lens are an optical pickup lens and a camera lens. Examples of optical waveguides are arrayed waveguides and planar optical circuits.

The optical member has a problem in that if the grating interval, the refractive index, the optical path length, and the like change with changes in temperature, the characteristics will fluctuate. According to the optical member or the fixing member or the support substrate of the optical member using the above-mentioned solid composition and molded body, such variation in characteristics of the optical member due to temperature can be reduced.

[adhesive] Examples of adhesives include thermosetting resins such as epoxy resins and silicone resins as matrix materials, and the above-mentioned particles. The adhesive can be liquid or solid before hardening. The cured product of the adhesive can suppress cracks due to its low coefficient of thermal expansion. It is suitable for heat-resistant adhesive members, etc., which are subjected to heat loads. [Example]

The present invention will be described in further detail below by means of examples. 1. Crystal structure analysis of particle swarms For the analysis of the crystal structure, use a powder X-ray diffraction measurement device SmartLab (manufactured by Rigaku Co., Ltd.), change the temperature under the following conditions, perform powder X-ray diffraction measurement on the particle group, and obtain a powder X-ray diffraction pattern . For the compound constituting the crystal, based on the obtained powder X-ray diffraction pattern, the software PDXL2 (manufactured by Rigaku Co., Ltd.) was used to refine the lattice constant by the least square method, and two lattice constants, that is, the length of the a-axis, were obtained. and the c-axis length.

Measuring device: powder X-ray diffraction measuring device SmartLab (manufactured by Rigaku Co., Ltd.) X-ray generator: CuKα ray source voltage 45 kV, current 200 mA Slit: slit width 2 mm Scanning step: 0.02 deg Scanning range: 5-80 deg Scanning speed: 10 deg/min X-ray detector: One-dimensional semiconductor detector Measuring gas: Ar 100 mL/min Sample stage: Made of special glass substrate SiO ₂

2. Measurement of BET specific surface area (S _BET ) of particle population The BET specific surface area of particles was measured by the following method. Pretreatment: dry the particle group at 200° C. for 30 minutes in a nitrogen atmosphere. Measurement: Measurement was performed by BET flow method. Measuring conditions: use the mixed gas of nitrogen and helium. The ratio of nitrogen in the mixed gas was set to 30% by volume, and the ratio of helium in the mixed gas was set to 70% by volume. Measuring device: BET specific surface area measuring device Macsorb HM-1201 (manufactured by Mountech Co., Ltd.)

3. Measurement of Particle Size Distribution of Particle Group The particle size distribution of the particle group was measured by the following method. Pretreatment: Add 99 parts by weight of water to 1 part by weight of the particle group for dilution, and perform ultrasonic treatment with an ultrasonic cleaning machine. The ultrasonic treatment time was set to 10 minutes, and as an ultrasonic cleaning machine, NS200-6U manufactured by Nippon Seiki Seisakusho Co., Ltd. was used. As the frequency of ultrasonic waves, it is implemented at about 28 kHz. Measurement: Measure the particle size distribution of the volume-based particle group by the laser diffraction scattering method. Measuring conditions: The refractive index of Ti ₂ O ₃ was set to 2.40. Measuring device: laser diffraction particle size distribution measuring device Mastersizer 2000 (manufactured by Malvern Instruments Ltd.) S _PSD was calculated based on the obtained particle size distribution of the particle group and the assumption that each particle is spherical. Also, D50 of the particle swarm was obtained.

4. Measurement of porosity of particle group The apparent density of the particle group was measured by a method based on JISZ 8807 using a pycnometer with a capacity of 10 mL (manufactured by AS ONE Co., Ltd.). Use water as the liquid. When the material of the particle group is Ti ₂ O ₃ , the true density of Ti ₂ O ₃ is assumed to be 4.49 g/cm ³ for calculation. Using the apparent density of the particle group and the true density of the particle group to calculate the porosity of the particle group according to formula (2). Porosity (%)=(1-apparent density of particle group/true density of particle group)×100…(2)

5. Evaluation of thermal expansion control characteristics (epoxy resin composite materials) The composite material of particle group and epoxy resin was produced by the following method, and the thermal expansion control characteristics were evaluated. By adding 57.5 g of epoxy resin (manufactured by Sumitomo Chemical Co., Ltd., ELM-100), 26.4 g of hardener (manufactured by Tokyo Chemical Co., Ltd., bis(4-aminophenyl) sulfide), and 0.3 g of hardening accelerator (Tokyo Chemical Co., Ltd., piperidinium trifluoroborate) was mixed to obtain an uncured epoxy resin composition. A mixture was obtained by mixing 5.0 g of the particle groups of Examples and Comparative Examples with 1.3 g of an unhardened epoxy resin composition. The resulting mixture was put into a mold and cured at 180° C. for 5 minutes while applying pressure, cooled to room temperature, taken out from the mold, and cured at 220° C. for 2 hours to obtain an epoxy resin composite material.

The thermal linear expansion coefficient of the obtained epoxy resin composite material was measured using the following apparatus. Measuring device: Thermo plus EVO2 TMA series Thermo plus 8311 As measurement conditions, temperature range: -10°C to 160°C, temperature change rate: 10°C/min, sampling interval: 2.7 seconds. Reference Solid: Silicon Oxide

As a representative size of a measurement sample of a solid composition, it is set at 15 mm×4 mm×4 mm. The longest side of the solid composition measurement sample is set as the sample length L, and the sample length L(T) at the temperature T is measured. The dimensional change rate ΔL(T)/L(30°C) with respect to the sample length (L(30°C)) at 30°C was calculated by the following formula. ΔL(100℃)/L(30℃)=(L(100℃)－L(30℃))/L(30℃)

When the rate of dimensional change at 100°C, ie, ΔL(100°C)/L(30°C), is less than 0.1%, it is evaluated that the thermal expansion control property is good.

(Examples 1-2 and Comparative Examples 1-2) The particle groups of Examples 1-2 and Comparative Examples 1-2 were obtained by the following method.

<Example 1><Step1> 1000 g of 2 mmϕ zirconia balls and 166.7 g of TiO ₂ (manufactured by Ishihara Sangyo Co., Ltd., CR -EL), and 33.3 g of Ti (manufactured by High Purity Chemical Research Institute Co., Ltd., <38 μm), a 1 L polyethylene bottle was placed on the ball mill stand, and the ball mill was mixed at a speed of 60 rpm for 4 hours to produce raw materials Mix powder 1.

Fill the above-mentioned raw material mixed powder 1 into a container for calcination (manufactured by NIKKATO Co., Ltd., SSA-T SAYA 90 square), and then put it into an electric furnace (manufactured by MOTOYAMA Co., Ltd., PCR), and replace the gas in the electric furnace with Ar, The raw material mixed powder is calcined. The calcination program was set as follows: the temperature was raised from 0° C. to 1100° C. over 11 hours, kept at 1100° C. for 1 hour, and the temperature was lowered from 1100° C. to 0° C. over 11 hours. During the operation of the calcination program, Ar gas was blown in at 5 L/min. After calcination, intermediate powder 1 was obtained.

<Step 2> The intermediate powder 1 was pulverized using a batch type Ready Mill (manufactured by AIMEX Co., Ltd., RM B-08). Use an 800 cm ³ container to pulverize at 1348 rpm and a peripheral speed of 5 m/s. Using ZrO ₂ beads with a particle diameter of 0.5 mm, they were mixed at a ratio of 113 g of ethanol, 675 g of ZrO ₂ , and 180 g of intermediate powder, and pulverized for 60 minutes. After pulverization, powder A1 was obtained.

50 g of powder A1, 200 g of pure water, 10 g of a 10 wt % aqueous solution of polyvinyl alcohol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., PVA-3500), and polyglycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. , PEG-400) mixed to obtain slurry B1.

The slurry B1 was spray-dried using a small spray dryer (manufactured by Yamato Scientific Co., Ltd.). Under the conditions of a pressure of 1.0 MPa, an outlet temperature of 85°C, and a display value of 40 on the aspirator, the output of the infusion pump is properly adjusted in such a way that the outlet temperature is constant, and spray drying is carried out. After spray drying, precursor powder 1 was obtained.

＜Step 3＞ Fill the precursor powder 1 into a calcination container (manufactured by AS ONE Co., Ltd., calcined crystal boat No. 5), and then put it into a tubular furnace (manufactured by MOTOYAMA Co., Ltd., DSPSH28), and replace the inside of the tubular furnace with Ar. gas to calcine the precursor powder. The calcination program was set as follows: the temperature was raised from 0° C. to 1150° C. over 11.5 hours, kept at 1150° C. for 1 hour, and then the temperature was lowered from 1150° C. to 0° C. over 11.5 hours. During the operation of the calcination program, Ar gas was blown in at 100 mL/min. After calcination, the particle group of Example 1 was obtained.

<Example 2> ＜Step 1＞ Raw material mixed powder 1 was produced by the method described in Example 1.

Fill the above-mentioned raw material mixed powder 1 into a container for calcination (manufactured by NIKKATO Co., Ltd., SSA-T SAYA 150 square), and then put it into an electric furnace (manufactured by NEMS Co., Ltd., FD-40×40×60-1Z4-18TMP) In the process, the gas in the electric furnace is replaced with Ar, and the raw material mixed powder is calcined. The calcination program was set as follows: the temperature was raised from 0° C. to 1150° C. over 11.5 hours, kept at 1150° C. for 1 hour, and then the temperature was lowered from 1150° C. to 0° C. over 11.5 hours. During the operation of the calcination program, Ar gas was blown in at 2 L/min. After calcination, intermediate powder 2 was obtained.

<Step 2> The intermediate powder 2 was pulverized using a batch type Ready Mill (manufactured by AIMEX Co., Ltd., RM B-08). Use an 800 cm ³ container to pulverize at 1348 rpm and a peripheral speed of 5 m/s. Using ZrO ₂ beads with a particle diameter of 0.5 mm, they were mixed at a ratio of 113 g of ethanol, 675 g of ZrO ₂ , and 2 80 g of intermediate powder, and pulverized for 60 minutes. After pulverization, powder A2 was obtained.

50 g of powder A, 200 g of pure water, 10 g of a 10 wt % aqueous solution of polyvinyl alcohol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., PVA-3500), and polyglycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. , PEG-400) mixed to obtain slurry B2.

The slurry B2 was spray-dried by the method described in Example 1 to obtain the precursor powder 2.

＜Step 3＞ Fill the precursor powder 2 into a calcination container (manufactured by AS ONE Co., Ltd., calcined crystal boat No. 5), and then put it into a tubular furnace (manufactured by MOTOYAMA Co., Ltd., DSPSH28), and replace the inside of the tubular furnace with Ar. gas to calcine the precursor powder. The calcination program was set as follows: the temperature was raised from 0° C. to 1220° C. over 12.2 hours, kept at 1220° C. for 5 hours, and then the temperature was lowered from 1220° C. to 0° C. over 12.2 hours. During the operation of the calcination program, Ar gas was blown in at 100 mL/min. After calcination, the particle group of Example 2 was obtained.

＜Comparative example 1＞ Utilize the method described in embodiment 1 to obtain raw material mixed powder. Fill 1000 g of the above-mentioned raw material mixed powder into a container for calcination (manufactured by NIKKATO Co., Ltd., SSA-T SAYA 150 square), and then put it into an electric furnace (manufactured by NEMS Co., Ltd., FD-40×40×60-1Z4-18TMP ), the gas in the electric furnace is replaced with Ar, and the raw material mixed powder is calcined. The calcination program was set as follows: the temperature was raised from 0° C. to 1500° C. over 15 hours, kept at 1500° C. for 3 hours, and the temperature was lowered from 1500° C. to 0° C. over 15 hours. During the operation of the calcination program, Ar gas was blown in at 2 L/min. After calcination, powder C is obtained.

Add 1000 g of 2 mm ϕ zirconia balls and 161 g of powder C to a plastic 1 L polyethylene bottle (outer diameter 97.4 mm), place the 1 L polyethylene bottle on the ball mill stand, and rotate at 60 rpm Ball mill pulverization was performed for 4 hours to pulverize the intermediate powder. After pulverization, powder D was obtained. The pulverized powder was sprinkled on a 45 μm mesh sieve, and the powder that passed through the sieve was defined as the powder of Comparative Example 1.

<Comparative Example 2> Ti ₂ O ₃ (manufactured by High Purity Chemical Laboratory Co., Ltd., <45 μm) was used as the powder of Comparative Example 2.

Table 1 summarizes the results of each measurement in Examples 1-2 and Comparative Examples 1-2 obtained.

[Table 1] |dA(T)/dT| T＝150℃ (ppm/℃) S _BET /S _PSD Porosity (%) D50 (μm) ∆L(100℃) /L(30℃) (%) Example 1 40 11.0 4.4 11 0.07 Example 2 36 4.9 2.5 11 0.08 Comparative example 1 2.5 1.8 16 0.10 Comparative example 2 3.3 0.4 27 0.10

According to the particle group of the embodiment, the rate of dimensional change in the solid composition is reduced. That is, the particle group of the embodiment is a particle group excellent in thermal expansion control characteristics.

2: crystal 4: Particles 6: closed air hole

Fig. 1 is a schematic cross-sectional view of particles according to one embodiment of the present invention.

2: crystal

4: Particles

6: closed air hole

Claims (14)

A particle group, wherein each particle contains a plurality of crystals, and the particle group satisfies the following requirement 1, and at least one of the following requirements 2 and 3; Requirement 1: At least one temperature T1 among -200°C to 1200°C , |dA(T)/dT| is above 10 ppm/°C; A is (lattice constant of the a-axis (short axis) of the above-mentioned crystal)/(lattice constant of the c-axis (long axis) of the above-mentioned crystal), Each lattice constant is obtained by X-ray diffraction measurement of the above-mentioned particle group; Requirement 2: S _BET /S _PSD is 4.0 to 20.0; S _BET is the specific surface area of the above-mentioned particle group obtained by the BET method; S _PSD is The specific surface area of the virtual particle group, the virtual particle group has the same particle size distribution as the volume-based particle size distribution of the above-mentioned particle group obtained by the laser diffraction scattering method, and the same as the true density of the above-mentioned particle group True density, and each of the above-mentioned imaginary particles has the shape of a true sphere; Requirement 3: The porosity defined by the following formula is 2.0-20.0%; Porosity (%)=(1-apparent density of the above-mentioned particle group/the above-mentioned particle group True density) × 100. The particle swarm as claimed in claim 1 satisfies all of the above-mentioned requirements 1-3. The particle group according to claim 1 or 2, wherein the diameter D50 at which the cumulative frequency reaches 50% in the volume-based particle size distribution curve of the above-mentioned particle group obtained by the laser diffraction scattering method is 1-100 μm. The particle group according to any one of claims 1 to 3, wherein the above-mentioned crystals are metal oxides. The particle group according to claim 4, wherein the metal oxide is a metal oxide containing a metal having d electrons. The particle group according to claim 4 or 5, wherein the metal oxide is a metal oxide containing titanium. The particle group according to claim 6, wherein the metal oxide containing titanium is _TiOx (x=1.30-1.66). A composition comprising the particle group according to any one of claims 1 to 7. The composition as claimed in item 8, which has a powder form. The composition according to claim 8, further comprising a matrix material. The composition according to claim 8, further comprising an uncured curable resin. A shaped body, which is the particle group according to any one of claims 1 to 7 or the shaped body of the composition according to claim 8 or 9. A method for manufacturing the particle swarm according to any one of claims 1 to 7, comprising: Step 1, calcining the raw material to obtain an intermediate; step 2, pulverizing the above intermediate to obtain a precursor; and step 3, calcining the above precursor, and the calcination temperature in the above step 1 and step 3 is 1000-1300°C. The method according to claim 13, further comprising the step of granulating the precursor by spray drying to obtain the granular precursor between the above step 2 and step 3.

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