Novel compound powder

Abstract

Provided is a novel compound powder which exhibits negative thermal expansion characteristics in a lower temperature range and can be used as a negative thermal expansion material having a higher thermal shrinkage percentage. This compound powder contains at least one element A selected from a specific element group, e.g., P. The compound powder is a composite comprising base material particles formed from a compound containing the element A and oxygen (O), and a coating layer coating the base material particle surfaces and formed from a metal compound containing Ca and the element A, and has negative thermal expansion characteristics. The compound powder may be one which has negative thermal expansion characteristics and in which, when a filtrate is used as a test liquid for ion elution testing, the amount of ions of at least one kind of the element A eluted into the test liquid is 3000 mass ppm or less per 1 g of a sample of the compound powder, said filtrate having been obtained by storing and sealing the sample and purified water in a pressure-resistant container at room temperature and subjecting a treated liquid which has undergone a heating pressurization treatment to solid-liquid separation under prescribed conditions to remove an insoluble part.

Description

Novel compound powder

[0001] The present invention relates to a novel compound powder containing a Ca (calcium)-containing coating layer and having negative thermal expansion properties. Further, the present invention preferably relates to a novel compound powder containing a Ca (calcium)-containing coating layer, having negative thermal expansion properties, and capable of suppressing the elution of specific ions under predetermined conditions.

[0002] In recent years, in technical fields that require high precision, such as highly developed electronic devices, optical devices, fuel cells, and sensors, the control and suppression of thermal expansion of solid materials have been strongly demanded. In particular, when constructing precision devices such as semiconductor devices that require high precision at the nanometer level by combining multiple materials, if positional deviation, interfacial peeling, disconnection, warping, cracks, etc. occur due to differences in the thermal expansion coefficients between the materials, it may become a serious problem. Therefore, technologies for highly controlling thermal expansion are required.

[0003] While many substances thermally expand with an increase in temperature, it is also known that negative thermal expansion materials having a negative thermal expansion coefficient with the property that the volume decreases with an increase in temperature are rarely present. As one of the technologies for controlling the thermal expansion of precision devices, for example, a technology for controlling the thermal expansion coefficient of the entire device by adding a negative thermal expansion material in combination with a matrix material (resin, glass, metal, etc.) having a large positive thermal expansion coefficient and a material having a low positive thermal expansion coefficient (e.g., silica) as needed has attracted attention. Examples of negative thermal expansion materials include, for example, β-eucryptite, zirconium tungstate (ZrW ２ O ８ ), zirconium tungsten phosphate (Zr ２ WO ４ (PO ４ ) ２ ), Zn ｘ Cd １－ｘ (CN ２ ), manganese nitride, bismuth nickel ferrite, etc. are known.

[0004] For example, in Patent Document 1, zirconium oxide ZrO ３ with respect to tungsten trioxide WO ２The negative thermal expansion material Zr is characterized by mixing raw materials in a stoichiometric ratio such that the sum of the substitution element X with the substitution amount x is 1 molar ratio, forming a powder with a bipolar particle size distribution consisting of small particles with particle sizes within a predetermined range and large particles with particle sizes within a predetermined range, and then placing the raw material powder into a desired mold and sintering it. （１－ｘ） X ｘ W ２ O ８ A method for synthesizing (where X is a substitution element for zirconium Zr, 0 ≤ x << 1) has been reported. Patent Document 1 states that this synthesis method has the effect of synthesizing large, high-density heat-shrinkable ceramics without press molding of the raw material powder. In addition to Patent Document 1, development is underway on new negative thermal expansion materials with various compositions and properties, as well as methods for manufacturing them.

[0005] For example, Patent Document 2 reports a negative thermal expansion material containing an oxide represented by a general formula that includes at least one element selected from Mg, Al, Zn, etc., and / or Cu, V, and P. Patent Document 3 reports a lead sealing glass and magnesium pyrophosphate (Mg ２ P ２ O ７ Mill additives of pyrophosphate crystalline materials consisting of ) particularly MgO and P present in approximately stoichiometric molar ratios of magnesium pyrophosphate. ２ O ５ A sealing material having a negative coefficient of thermal expansion has been reported, which includes crystallized glass that is essentially made from. Patent Document 4 describes a material that is substantially P ２ O ５ Negative thermal expansion materials consisting of crystalline phosphate glass particles with one cation selected from magnesium, zinc, aluminum, etc., and mixtures of organic polymers have been reported. Patent document 5 reports modified zirconium tungstate phosphate, which is a negative thermal expansion material whose surface is coated with an inorganic compound containing one or more elements selected from Zn, Mg, V, etc., and it is shown that the amount of phosphorus ions eluting from modified zirconium tungstate phosphate under predetermined conditions can be suppressed by such surface modification.

[0006] Japanese Patent Publication No. 2003-342075, International Publication No. 2022 / 114004, U.S. Patent No. 5089445, Japanese Patent Publication No. Hei 08-048809, Japanese Patent Publication No. 2020-147486

[0007] For example, in precision equipment such as semiconductor devices that require high-precision thermal expansion control, the actual operating temperature during the heat cycle of the equipment is often below 150°C. Therefore, there is a need for materials that exhibit negative thermal expansion characteristics in such temperature ranges. However, many conventional negative thermal expansion materials only exhibit negative thermal expansion characteristics when they reach temperatures above 150°C. Consequently, research is ongoing to find specific compositions of negative thermal expansion materials that exhibit negative thermal expansion characteristics in lower temperature ranges, such as below 150°C, and preferably achieve a higher thermal contraction rate (i.e., a lower negative thermal expansion rate).

[0008] Furthermore, as mentioned above, negative thermal expansion materials can be used in mixture with matrix materials (resins, glass, metals, etc.). For example, when a resin is used as the matrix material, trace amounts of ions of the elements constituting the negative thermal expansion material may dissolve into the matrix resin as impurities. When negative thermal expansion materials are used in precision equipment such as semiconductor devices, it is preferable that the conductivity of the negative thermal expansion material is lower (i.e., the volume resistivity is higher). However, the undesirable consequence is that the dissolution of elemental ion impurities from the negative thermal expansion material into the matrix resin can impair the structural stability of the material itself, hinder the stable performance of negative thermal expansion characteristics, and may even lead to an increase in conductivity. Therefore, it is desirable to provide a negative thermal expansion material in which the dissolution of elemental ions is suppressed and, preferably, conductivity is kept low.

[0009] Therefore, an object of the present invention is to provide a novel compound powder that exhibits negative thermal expansion characteristics in a lower temperature range and can be used as a negative thermal expansion material with a preferably higher thermal shrinkage coefficient. Another object of the present invention is to provide a novel compound powder that exhibits negative thermal expansion characteristics in a lower temperature range and can be used as a negative thermal expansion material with a preferably higher thermal shrinkage coefficient, and in which the elution of specific elemental ions, which are impurities, is suppressed. Yet another object of the present invention is to provide a novel compound powder that exhibits negative thermal expansion characteristics in a lower temperature range and can be used as a negative thermal expansion material with a preferably higher thermal shrinkage coefficient, and in which the elution of specific elemental ions, which are impurities, is suppressed, and consequently, the conductivity is kept low.

[0010] As a result of diligent research, the inventors have discovered a novel compound powder that exhibits negative thermal expansion characteristics in a lower temperature range and can preferably be used as a negative thermal expansion material with a higher thermal shrinkage coefficient. This compound powder is a composite comprising base particles formed from a compound containing a specific element selected from the group of elements including P and O (oxygen), and a coating layer formed from a metal compound containing Ca and a specific element that coats the surface of the base particles, thereby completing the present invention. Furthermore, as a preferred embodiment of the present invention, the inventors have discovered a novel compound powder that exhibits negative thermal expansion characteristics in a lower temperature range and can preferably be used as a negative thermal expansion material with a higher thermal shrinkage coefficient, and in which the elution of specific element ions is suppressed. This compound powder is a composite comprising base particles formed from a compound containing a specific element selected from the group of elements including P and O (oxygen), and a coating layer formed from a metal compound containing Ca and a specific element that coats the surface of the base particles, wherein the amount of at least one ion of this specific element that elutes in an ion elution test under predetermined conditions is 3000 ppm by mass per gram of sample.

[0011] In other words, the compound powder according to the present invention is as follows: A compound powder containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, wherein the compound powder is a composite comprising base particles formed from a compound containing element A and O (oxygen), and a coating layer formed from a metal compound containing Ca and element A that coats the surface of the base particles, and having a temperature range in which the coefficient of linear expansion (α) is less than 0 ppm / K in a temperature range of at least 0°C to 70°C, or having a temperature range in which the dimensional change ratio (ΔL / L) is less than 0 in a temperature range of at least 0°C to 70°C, or -0.5 × 10 in a temperature range of at least 30°C to 70°C －３ A compound powder having the following dimensional change ratio (ΔL / L).

[0012] Furthermore, the method for producing the compound powder according to the present invention is as follows: A method for producing a compound powder containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, comprising the steps of: providing base particles formed from a compound containing the element A and O (oxygen); and applying a coating medium containing a Ca-containing compound to the surface of the base particles and firing it to obtain a composite product including a coating layer formed from a metal compound containing Ca and element A, wherein the compound powder has a temperature range in which the coefficient of linear expansion (α) is less than 0 ppm / K in a temperature range of at least 0°C to 70°C, or has a temperature range in which the dimensional change ratio (ΔL / L) is less than 0 in a temperature range of at least 0°C to 70°C, or has a temperature range in which the dimensional change ratio (ΔL / L) is less than 0 in a temperature range of at least 30°C to 70°C. －３ A method for producing the compound powder having the following dimensional change ratio (ΔL / L).

[0013] In this specification, the term "ion" of at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V (the ion whose elution amount is measured in the ion elution test according to a preferred embodiment of the present invention) includes ions bonded with other atoms (one or more) and ions with different valencies, as long as they contain a specific element A. For example, the P ion may include PO ４ ３－ HPO ４ ２－ , H ２ PO ４ － , P ２ O ７ ４－ , P ３ O １０ ５－ , PO ３ － It includes.

[0014] The compound powder according to the present invention exhibits negative thermal expansion characteristics in a lower temperature range and can be used as a negative thermal expansion material with preferably a higher thermal shrinkage coefficient. Furthermore, according to a preferred embodiment, a compound powder can be obtained in which the elution of at least one ion of a specific element such as P is suppressed. Moreover, according to a preferred embodiment, a compound powder can be obtained in which the conductivity is kept low, i.e., the volume resistivity, which is an indicator of insulating properties, is increased. According to the method for producing the compound powder of the present invention, by applying a coating medium containing a Ca-containing compound to the base particles and firing by a simple means, a compound powder can be obtained that exhibits negative thermal expansion characteristics in a lower temperature range and can be used as a negative thermal expansion material with preferably a higher thermal shrinkage coefficient, and in which the elution of at least one ion of a specific element such as P is effectively suppressed.

[0015] <Compound Powder According to the Present Invention> The compound powder of the present invention is a composite comprising (a) base particles formed from a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), and (b) a coating layer formed from a metal compound containing Ca and element A that coats the surface of the base particles (a), and having a temperature range in which the coefficient of linear expansion (α) is less than 0 ppm / K in a temperature range of at least 0°C to 70°C, or having a temperature range in which the dimensional change ratio (ΔL / L) is less than 0 in a temperature range of at least 0°C to 70°C, or -0.5 × 10 in a temperature range of at least 30°C to 70°C. －３ The compound powder containing element A has the following dimensional change ratio (ΔL / L), that is, it has negative thermal expansion characteristics according to the above definition in a temperature range of at least 0°C to 70°C.

[0016] In a compound powder, the compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is not particularly limited as long as it contains these specific elements A and O. The compound containing at least one element A and O may be a compound containing any two or more elements A and O selected from the group consisting of P, Zn, Cu, Mg, and V. Furthermore, the compound containing at least one element A and O may be a mixture of any two or more compounds in any ratio.

[0017] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, as well as O (oxygen), which forms the base particle (a), is a negative thermal expansion material having a negative coefficient of thermal expansion, characterized by a decrease in volume as the temperature rises. Such negative thermal expansion materials typically have a temperature range in which the coefficient of linear expansion (α: as defined below) is usually less than 0 ppm / K, preferably less than -10 ppm / K, more preferably less than -20 ppm / K, even more preferably less than -30 ppm / K, and even more preferably less than -40 ppm / K. By using such a negative thermal expansion material that exhibits a low coefficient of linear expansion in an appropriate temperature range as a compound containing elements A and O that form the base particles (a), it is possible to obtain a compound powder having negative thermal expansion characteristics that are not significantly different from those of the base particles, even after forming a composite including a thin coating layer (b) thereon.

[0018] In this specification, the "coefficient of linear expansion (α)" is defined by the following formula (A): Coefficient of linear expansion (α) [unit ppm / K] = (1 / L) × (ΔL / ΔT) × 10 ６ ...Equation (A) In the equation, L refers to the length of the sample (μm), ΔL refers to the change in sample length (μm) within the specified temperature range, and ΔT refers to the temperature difference (K) within the specified temperature range. In this specification, the "dimensional change ratio," which is the ratio of the change in sample length within the specified temperature range, is defined by the following equation (B). Dimensional change ratio (dimensionless) = ΔL / L ...Equation (B) ΔL and L in the equation are as defined above. The coefficient of linear expansion (α) is expressed in the following relationship with the dimensional change ratio ΔL / L. Coefficient of linear expansion (α) [ppm / K] = {(ΔL / L) / ΔT} × 10 ６The definitions and relationships for the coefficient of linear expansion (α) and the dimensional change ratio (ΔL / L) described herein can also be applied similarly to the compound powders of any of the embodiments described later.

[0019] In one embodiment, the compound containing elements A and O (oxygen) that form the base particles (a) of the compound powder may have a temperature range in which the dimensional change ratio (ΔL / L) is usually less than 0, preferably in any range within the temperature range of 0°C to 200°C, more preferably in the temperature range of room temperature or higher (for example, 0°C or higher, 10°C or higher, 20°C or higher or 30°C or higher) to 150°C or lower, 70°C or lower or 50°C or lower. Preferably, -0.5 × 10 －３ It may have a temperature range of the following, and more preferably -1 × 10⁻⁶. －３ It may have a temperature range of the following, and more preferably -2 × 10 －３ It may have a temperature range of the following, and more preferably -3 × 10 －３ The following temperature range may be observed: In other embodiments, the compound containing elements A and O that form the base particle (a) is preferably in any range within the temperature range of 0°C to 200°C, and more preferably in a temperature range of room temperature or higher (e.g., 0°C or higher, 10°C or higher, 20°C or higher, or 30°C or higher) up to 150°C, where the dimensional change ratio (ΔL / L) is -5 × 10 －３ It may have the following temperature range: -6 × 10 －３ It may have the following temperature range: -7 × 10 －３ It may have the following temperature range: -8 × 10 －３ It may have a temperature range of the following, or -10 × 10 －３ The following temperature range may be included.

[0020] The dimensional change ratio (ΔL / L: the ratio of length change due to linear expansion) for the base particles in this specification may be measured by mixing the base particles with a resin component to form a resin composition, or by measuring the base particles in the state of a compacted molded body (unsintered), or by sintering this compacted molded body. The dimensional change ratio can be measured by a thermomechanical analyzer (TMA), for example, by a Hitachi High-Tech TA7000. The description here can also be applied to the base particles constituting the compound powder of any of the embodiments described later. When calculating the coefficient of linear expansion (α) using the above formula (A), when substituting values ​​for L to ΔL as described above, the sample length in units of mm displayed in the above device should be set to 10 ３ You can convert it to the unit μm by multiplying by two.

[0021] By including base particles (a) formed from a compound powder containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, as well as O (oxygen), a negative thermal expansion material exhibiting negative thermal expansion characteristics in a lower temperature range can be obtained. Furthermore, by a preferred selection of metal oxides containing P and at least one element selected from the group consisting of Zn, Cu, Mg, Ca, and V, a negative thermal expansion material with a higher thermal shrinkage rate can be obtained.

[0022] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound with the general formula: Zn ２－ｘ T ｘ P ２－ｙ A ｙ O ７±δ(T includes at least one element selected from Mg, Ca, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ta, W, and Bi; A includes at least one element selected from Al, Si, V, Ge, and Sn, satisfying 0 ≤ x < 2 and 0 ≤ y ≤ 2; δ is a value determined to satisfy the charge neutrality condition, except for (x, y) = (0, 0) and (0, 2).) It should be noted that in this specification, the "charge neutrality condition" does not have to be completely neutral, and compositions with oxygen deficiencies or excesses within an acceptable range for the compound may be included.

[0023] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound with the general formula: Cu ２－ｘ R ｘ V ２－ｙ P ｙ O ７±δ It may contain at least one oxide represented by (R is at least one element selected from Mg, Al, Si, Ti, Cr, Mn, Fe, Co, Ni, Zn, Sn, satisfying 0 ≤ x ≤ 2 and 0 < y < 2, and δ is a value determined to satisfy the charge neutrality condition).

[0024] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound with the general formula: Cu in which an Al atom is solid-dissolved. ｘ M ｙ V ｚ O ｔ±δThe material may contain at least one oxide represented by the formula (wherein M represents a metallic element with an atomic number of 11 or higher other than Cu, V, and Al, preferably one or more metallic elements selected from Zn, Ga, Fe, Mg, Co, Mn, Ba, and Ca. x represents 1.60 ≤ x ≤ 2.40, y represents 0.00 ≤ y ≤ 0.40, z represents 1.70 ≤ z ≤ 2.30, t represents 6.00 ≤ t ≤ 9.00, and δ is a value determined to satisfy the charge neutrality condition, provided that 1.00 ≤ x + y ≤ 3.00. Also, when element M is included, the number of moles of Al atoms on an atomic basis > the number of moles of M atoms on an atomic basis.)

[0025] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound in which a Li atom is in solid solution, with the general formula: (Cu ｘ M ｙ ) (V ａ P ｂ ) O ｔ±δ It may contain at least one oxide represented by the formula (wherein M represents a metallic element with an atomic number of 11 or higher other than Cu and V, preferably one or more selected from Zn, Ga, Fe, Mg, Co, Mn, Al, Ba, and Ca. x represents 1.60 ≤ x ≤ 2.40, y represents 0.00 ≤ y ≤ 0.40, a represents 1.60 ≤ a ≤ 2.40, b represents 0.00 ≤ b ≤ 0.40, t represents 5.00 ≤ t ≤ 9.00, and δ is a value determined to satisfy the charge neutrality condition, provided that 1.60 ≤ x + y ≤ 2.40 and 1.60 ≤ a + b ≤ 2.40).

[0026] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound with the general formula: Zr ｘ (WO ４ ) ｙ±δ１ (PO ４ ) ｚ±δ２ It may contain at least one oxide represented by the formula (wherein 1.7 ≤ x ≤ 2.3, 0.8 ≤ y ≤ 1.2, 1.7 ≤ z ≤ 2.3, and δ1 and δ2 are values ​​that are independently determined to satisfy the charge neutrality condition).

[0027] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound with the general formula: Zr ２．００－ｂ M ｂ S Ｙ P Ｚ O １２．００±δ The material may contain at least one oxide represented by the formula (wherein M is at least one selected from Ti, Ce, Sn, Mn, Hf, Ir, Pb, Pd, Cr, W, Mo, 0 ≤ b < 2.00, 0 < Y < 0.30, Z ≥ 2.00, and δ is a value determined to satisfy the charge neutrality condition).

[0028] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound with the general formula: Zr ２．００－ｂ M ｂ S Ｙ P Ｚ O １２．００±δ The material may contain at least one oxide represented by the formula (wherein M is at least one selected from Ti, Ce, Sn, Mn, Hf, Ir, Pb, Pd, Cr, W, Mo, 0 ≤ b < 2.00, 0.30 ≤ Y ≤ 1.00, Z > 2.00, and δ is a value determined to satisfy the charge neutrality condition).

[0029] In a compound powder, a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particle (a), is, for example, a compound with the general formula: Ti ２－ｘ M ｘ O ３±δ (M may contain at least one oxide represented by (M is an element selected from Mg, Al, Si, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ta, W, Bi, satisfying 0 ≤ x < 2, and δ is a value determined to satisfy the charge neutrality condition. However, M includes at least one element selected from the group consisting of Zn, Cu, Mg, and V.)

[0030] In a compound powder, the metal compound that forms the coating layer (b) covering the surface of the base particles (a) is not particularly limited as long as it contains Ca and element A. The metal compound that forms the coating layer (b) covering the surface of the base particles (a) may contain at least one metal compound selected from the group consisting of oxides, oxynitrides, nitrides, carbides, and sulfides of element A and Ca. Preferably, the metal compound that forms the coating layer (b) covering the surface of the base particles (a) contains or is derived from at least one oxide of element A and Ca (i.e., a compound containing element A, Ca, and O (oxygen)). In this way, by having the coating layer (b) contain a metal compound of a specific type of element A and Ca, such as P derived from the base particles (a), a compound powder can be obtained in which the elution of at least one ion of element A is suppressed. Furthermore, by a preferred selection of the types of element A and metal compound, a compound powder can be obtained in which conductivity is kept low, i.e., volume resistivity is increased.

[0031] In a preferred embodiment of the compound powder, the element A of the compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen), which forms the base particles (a), includes P, and the metal compound containing Ca and element A that constitutes the coating layer (b) covering the surface of the base particles (a) may include a Ca-P-O composite oxide. In another preferred embodiment, the element A of the compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O, which forms the base particles (a), includes at least one selected from the group consisting of Zn, Cu, Mg, and V, and the metal compound containing Ca and element A that constitutes the coating layer (b) covering the surface of the base particles (a) may include a Ca-Zn-O composite oxide, a Ca-Cu-O composite oxide, a Ca-Mg-O composite oxide, a Ca-V-O composite oxide, or a mixture of two or more of these composite oxides. In further other preferred embodiments, the element A of the compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O, which forms the base particle (a), comprises P and one or more elements selected from the group consisting of Zn, Cu, Mg, and V. The metal compound containing Ca and element A that constitutes the coating layer (b) covering the surface of the base particle (a) may include a Ca-Zn-P-O composite oxide, a Ca-Cu-P-O composite oxide, a Ca-Mg-P-O composite oxide, a Ca-V-P-O composite oxide, or a mixture of two or more of these composite oxides. By selecting specific types of element A and metal compounds, the elution of at least one ion of element A can be effectively suppressed, and a compound powder can be obtained in which conductivity is kept sufficiently low, i.e., volume resistivity is greatly increased. From this viewpoint, it is preferable that the metal compound forming the coating layer (b) contains at least one oxide of element A and Ca (i.e., a compound containing element A, Ca, and O (oxygen)) or consists of these.In a preferred embodiment, the compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V and O (oxygen) that forms the base material particles (a) may include one or more kinds of Zn—Mg—P—O-based compounds. Particularly preferred examples of such Zn—Mg—P—O-based compounds include Zn. ２－ｘ Mg ｘ P ２ O ７ Examples of the oxide represented by are oxides. Here, x may be 0.1 or more and 0.8 or less, preferably 0.2 or more and 0.5 or less. By using such oxide base material particles (a), firing is easy, and a compound powder having high negative thermal expansion characteristics and being dense and stable can be obtained.

[0032] In the compound powder, the thickness of the coating layer (b) is not particularly limited, but may be, for example, 0.01 μm or more and 5 μm or less, preferably 0.02 μm or more and 4 μm or less, 0.03 μm or more and 3 μm or less, 0.04 μm or more and 2 μm or less, 0.05 μm or more and 1 μm or less, or 0.1 μm or more and 1 μm or less. The thickness of the coating layer (b) can be observed by a SEM image of the compound powder.

[0033] The compound powder may optionally be further surface-treated with respect to the coating layer (b). By surface-treating the compound powder with a predetermined surface treatment compound, insulation properties and chemical resistance can be improved, and it can contribute to improving the wettability with respect to the resin.

[0034] Examples of the surface treatment compound for the coating layer (b) are not particularly limited, and include organic compounds such as silane coupling agents, aluminate coupling agents, titanate coupling agents, zirconium coupling agents, organic carboxylic acids, and organic amines, and inorganic compounds such as silicon dioxide, aluminum oxide, zinc oxide, and titanium oxide. These surface treatment compounds can be used alone or in a mixed form of a plurality of kinds. For example, as the silane coupling agent of the surface treatment compound, various silane coupling agents such as epoxy-based, amino-based, vinyl-based, methacrylic-based, acrylic-based, mercapto-based, and alkyl-based can be used.

[0035] Even when the compound powder of the composite containing a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V and O (oxygen) that forms the base material particles (a) has a coating layer formed of a metal compound containing Ca and element A on its surface, it is preferable that substantially the same negative thermal expansion characteristics as those of the above compound that forms the base material particles (a) are maintained in such a compound powder of the composite. Therefore, like the base material particles (a) described above, the compound powder as the negative thermal expansion material usually has a linear expansion coefficient (α) in any range included in the temperature range of -200°C or higher and 500°C or lower, preferably in any range included in the temperature range of 0°C or higher and 200°C or lower, more preferably in the temperature range of room temperature or higher (for example, 0°C or higher, 10°C or higher, 20°C or higher, or 30°C or higher) and 150°C or lower, 70°C or lower, or 50°C or lower, and may have a temperature range where it is usually less than 0 ppm / K, preferably may have a temperature range where it is -10 ppm / K or lower, more preferably may have a temperature range where it is -20 ppm / K or lower, even more preferably may have a temperature range where it is -30 ppm / K or lower, and even more preferably may have a temperature range where it is -40 ppm / K or lower.

[0036] Also, like the base material particles (a) described above, the compound powder as the negative thermal expansion material usually has a dimensional change ratio (ΔL / L) in any range included in the temperature range of -200°C or higher and 500°C or lower, preferably in any range included in the temperature range of 0°C or higher and 200°C or lower, more preferably in the temperature range of room temperature or higher (for example, 0°C or higher, 10°C or higher, 20°C or higher, or 30°C or higher) and 150°C or lower, 70°C or lower, or 50°C or lower, and may have a temperature range where it is usually less than 0, preferably may have a temperature range where it is -0.5×10 －３ or less, more preferably may have a temperature range where it is -1×10 －３ or less, even more preferably may have a temperature range where it is -2×10 －３ or less, and even more preferably may have a temperature range where it is -3×10 －３The following temperature range may be observed: In other embodiments, the compound powder has a dimensional change ratio (ΔL / L) of -5 × 10 in any range typically included in the temperature range of -200°C to 500°C, preferably in any range included in the temperature range of 0°C to 200°C, and more preferably in a temperature range of room temperature or higher (e.g., 0°C or higher, 10°C or higher, 20°C or higher, or 30°C or higher) up to 150°C or 70°C or lower. －３ It may have a temperature range of the following, preferably -6 × 10 －３ It may have a temperature range of the following, more preferably -7 × 10 －３ It may have a temperature range of the following, and more preferably -8 × 10 －３ The temperature range may be as follows, and more preferably -10 × 10 －３ The following temperature range may be included.

[0037] The dimensional change ratio (ΔL / L: the ratio of change in length due to linear expansion) for compound powders in this specification may be measured by mixing the compound powder with a resin component to form a resin composition. The dimensional change ratio can be measured by a thermomechanical analyzer (TMA), such as the Hitachi High-Tech TA7000. The description herein can also be applied to compound powders of any embodiment described later.

[0038] By mixing compound powders of two or more negative thermal expansion materials, it is possible to create a material that exhibits gradual thermal shrinkage with two or more shrinkage temperature ranges. This suppresses the rapid shrinkage of the negative thermal expansion material. Therefore, for example, a resin composition containing a mixture of two or more such negative thermal expansion materials can reduce the difference in thermal expansion with the resin in the shrinkage temperature range compared to a resin composition containing only one negative thermal expansion material. The matters described here can be similarly applied to the compound powders of any embodiment described later.

[0039] The particle shape of the compound powder is not particularly limited and may be spherical, granular, plate-like, flaky, whisker-like, rod-like, filament-like, or crushed. From the viewpoint of achieving uniform mixing and dispersion when mixed with positive thermal expansion materials such as silica, and from the viewpoint of suppressing wear of the raw material mixing container and reducing the inclusion of impurities, it is preferable that the compound powder contains a large proportion of spherical particles. Furthermore, it is preferable that the compound powder contains a large proportion of spherical particles because it has the advantage of improving the fluidity of the resin composition and suppressing viscosity increase. The compound powder can be processed into compacted molded bodies. In addition, the compound powder or resin composition containing it can be processed into various shapes such as film materials and plate materials.

[0040] The compound powder preferably contains a large number of spherical particles with a sphericity (perfect sphericity) of 0.7 to 1.0. The content of spherical particles in the compound powder may be 75% or more, preferably 80% or more, based on the number of particles, from the viewpoint of achieving a uniform mixing and dispersion state when mixed with positive thermal expansion materials such as silica, suppressing wear of the raw material mixing container, and reducing the inclusion of impurities. Furthermore, this has the advantage of improving the fluidity of the resin composition and suppressing the increase in viscosity. In this specification, the sphericity of the compound powder can be measured as follows. A sample of the compound powder is observed at a magnification of 2500x using a scanning electron microscope (SU3500, manufactured by Hitachi High-Technologies Corporation) and three SEM images are obtained. For each of the three obtained SEM images, a binarization process of particles and background is performed as image adjustment. Subsequently, image analysis is performed on each of the 100 particles in the image. Using the image processing software ImageJ, drawing is performed along the particles, and after all drawing is complete, particle analysis is performed to obtain the average area and average circumference of each particle. Then, the sphericity of one SEM image is calculated using equation (1). The arithmetic mean of the sphericity values ​​obtained from the three images is taken as the sphericity (true sphericity). Sphericity of one particle = 4π × (average area of ​​one particle) / (average circumference of one particle)^2 ... (1) It has been known for some time that the concept of sphericity or true sphericity of compound powder itself, and that the closer the value is to 1, the higher the degree of spherical approximation of the particle shape, is the case. However, it is not known and is considered not easy to raise the sphericity of compound powder to 0.7 or higher using the calculation method defined above, which is unique to this application (this applies to all embodiments described later).

[0041] The average particle size of the compound powder (a composite containing base particles (a) and a coating layer (b)) is determined by the cumulative particle size D at 50% of the cumulative volume, as measured by laser diffraction scattering particle size distribution analysis, from the viewpoint of dispersibility in matrix materials such as resin, glass, and metal. ５０ It is preferable that the particle size is 0.05 μm or more and 100 μm or less. Volume cumulative particle size D of the compound powder ５０More preferably, the thickness may be 0.1 μm to 50 μm, 0.5 μm to 40 μm, 1 μm to 30 μm, 1 μm to 20 μm, or 1 μm to 10 μm.

[0042] The BET specific surface area of ​​the compound powder is 0.1 m². ２ / g or more 10m ２ It is preferable that the BET specific surface area is less than or equal to 0.1 m². Having a BET specific surface area within this range can improve the dispersibility of the compound powder in matrix materials such as resins, glass, and metals. The BET specific surface area of ​​the compound powder is more preferably 0.1 m². ２ / g or more 8m ２ It may be less than or equal to / g, and more preferably 0.1m ２ / g or more 5m ２ / g or less, 0.1m ２ / g or more 4m ２ / g or less, 0.1m ２ / g or more 3m ２ / g or less, 0.1m ２ / g or more 2m ２ / g or less, or 0.1m ２ / g or more 1m ２ It may be less than or equal to / g. Furthermore, from the viewpoint of dispersibility in matrix materials such as resin, glass, and metal, the BET specific surface area of ​​the compound powder may preferably be 10 times or less the BET specific surface area of ​​the base material particles (a) that are not compounded, and more preferably 5 times or less, 4 times or less, 3 times or less, 2 times or less, 1 time or less, or 0.5 times or less the BET specific surface area of ​​the base material particles (a).

[0043] The volume resistivity of the compound powder is 1.0 × 10⁻⁶ at 25°C, making it suitable for applications requiring insulating properties. ９ It is preferable that the resistivity is Ω·cm or greater. The volume resistivity of the compound powder is more preferably 5.0 × 10 at 25°C. ９ Ω・cm or more, 1.0×10 １０ Ω・cm or more, 5.0×10 １０ Ω・cm or more, 1.0×10 １１ Ω・cm or more, 5.0×10 １１ Ω·cm or greater, or 1.0 × 10⁻⁶ １２It may be Ω·cm or greater. In this specification, the volume resistivity of a compound powder can be measured, for example, by compressing the compound powder at a pressure of 63 MPa using the "MCP-PD51" powder resistance measurement system manufactured by Nitto Seiko Analytech Co., Ltd., and following the four-terminal method. Samples that exceed the measurement limit of this device can be measured using a pellet prepared by separately compressing it at a pressure of 63 MPa and measuring it using the High Resistance Meter High Resta UX / MCP-HT800 manufactured by Nitto Seiko Analytech Co., Ltd.

[0044] The method for producing the compound powder is not particularly limited, but for example, it includes the steps of: (1) providing base particles (a) formed from a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen); and (2) applying a coating medium containing a Ca-containing compound to the surface of the base particles (a) and firing it to obtain a composite product including a coating layer formed from a metal compound containing Ca and element A.

[0045] Step (1) of providing base particles (a) formed from a compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, and O (oxygen) can usually be appropriately selected and employed as a dry synthesis method or a liquid-phase synthesis method (hydrothermal reaction method).

[0046] A dry synthesis method for obtaining base particle (a) includes, for example, (i) preparing a raw material compound which is a single or multiple mixture containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V; (ii) obtaining a primary calcined product by calcining the raw material compound; (iii) obtaining a secondary calcined product by crushing and remixing the primary calcined product and then calcining it again; (iv) obtaining an additional calcined product by optionally performing step (c) at least once; (v) crushing the secondary calcined product or additional calcined product; (vi) optionally grinding the crushed secondary calcined product or additional calcined product; (vii) optionally sieving the ground secondary calcined product or additional calcined product with or without washing and decantation with water; and (viiii) Optionally, the process may include drying the sieved secondary or additional calcined product.

[0047] The starting material compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V is not particularly limited as long as it is a compound containing the desired element. The starting material compound may be at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V in its elemental form. An example of a starting material compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V that is suitably used in the dry synthesis method is a compound containing the element and an oxygen atom, for example, P ２ O ５ , ZnO, CuO, MgO, V ２ O ５ Examples include one or more of the following. For example, an example of a P-containing compound used as a raw material is phosphoric acid (H ３ PO ４ ), diammonium hydrogen phosphate ((NH ４ ) ２ HPO ４ ), ammonium dihydrogen phosphate (NH ４ H ２ PO ４ ), ammonium phosphate, pyrophosphate, polyphosphate, Zn ２ P ２ O７ Mg ２ P ２ O ７ Examples include one or more of the following.

[0048] The firing temperature at each firing stage in the dry synthesis method is not particularly limited, but may be, for example, 200°C or higher, 250°C or higher, or 300°C or higher, or 1200°C or lower, 1000°C or lower, or 900°C or lower. The firing temperature range at each firing stage in the dry synthesis method may be, for example, 200°C or higher and 1200°C or lower, or 250°C or higher and 1000°C or lower, or 300°C or higher and 900°C or lower. From the viewpoint of reliably obtaining a composite with the desired composition, it is preferable to set the firing temperature higher as the process progresses to the subsequent firing stages. The number of times the firing stage is repeated is usually two or three times, but it may be four or more times if necessary.

[0049] The optional grinding of the secondary or additionally fired material after crushing may be dry or wet grinding. Dry grinding can be performed using, for example, a jet mill with a collision plate or a jet mill that causes particles to collide with each other. Wet grinding can be performed, for example, by adding pure water and, if necessary, a small amount of dispersant to the crushed fired material, and while stirring, supplying beads such as small-diameter zirconia beads to a media-stirred bead mill.

[0050] Optional sieving performed on the crushed calcined material may involve, for example, a volume cumulative particle size D within the preferred range described above. ５０ A suitable sieve can be selected to obtain a compound powder having the properties of the material. Washing with water and decantation, which may be performed in conjunction with sieving, are preferably repeated until the desired conductivity (e.g., 20 μS / cm or less) is achieved. Drying, which is optionally performed on the sieved calcined material, may be carried out, for example, at a temperature of 50°C to 200°C, preferably 80°C to 150°C, for 30 minutes to 10 hours, preferably 1 hour to 8 hours.

[0051] A wet synthesis method for obtaining base material particles (a) may include, for example, (i) preparing a raw material compound which is a single or multiple mixture containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V; (ii) obtaining a hydrothermally treated mixture by hydrothermally treating the raw material compound; (iii) optionally separating the solid and liquid of the hydrothermally treated mixture and washing it; (iv) drying the hydrothermally treated mixture; and (v) calcining the dried mixture.

[0052] The raw material compound containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V is not particularly limited as long as it is a compound containing the desired element. The raw material compound may be at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V in its elemental form. Examples of raw material compounds containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V that are suitably used in liquid-phase synthesis (hydrothermal reaction) include one or more of the following: chloride salt or hydrate of the element, oxychloride salt or hydrate of the element, acetate or hydrate of the element, oxyacetate or hydrate of the element, sulfate or hydrate of the element, nitrate or hydrate of the element, carbonate or hydrate of the element, ammonium carbonate or hydrate of the element, sodium carbonate or hydrate of the element, potassium carbonate or hydrate of the element, polyacid or salt or hydrate of the element, oxide or hydrate of the element, etc. The raw material compound may be compounded with sulfuric acid as a sulfur raw material as needed. For example, an example of a P-containing compound used as a raw material compound is phosphoric acid (H ３ PO ４ ), diammonium hydrogen phosphate ((NH ４ ) ２ HPO ４ ), ammonium dihydrogen phosphate (NH ４ H ２ PO ４ Examples include one or more of the following: ammonium phosphate, pyrophosphate, polyphosphate, etc.

[0053] The hydrothermal treatment conditions for the raw material compounds in the liquid-phase synthesis method (hydrothermal reaction method) are not particularly limited, but for example, the reaction can be carried out continuously in a sealed container under pressure at a temperature of 100°C to 250°C, preferably 110°C to 230°C, for a period of time of, for example, 30 minutes to 100 hours, preferably 1 hour to 80 hours, 2 hours to 60 hours, or 3 hours to 40 hours.

[0054] In the liquid-phase synthesis method (hydrothermal reaction method), washing after solid-liquid separation may be performed, for example, by adding water to separate the solid-liquid again or by washing with water. This washing operation may be repeated multiple times. If sulfur (S) components are present in the system, washing can effectively remove them.

[0055] In the liquid-phase synthesis method (hydrothermal reaction method), the hydrothermally treated mixture may be dried, for example, at a temperature of 60°C to 200°C, preferably 50°C to 150°C, for about 30 minutes to 40 hours, preferably about 1 hour to 30 hours. Furthermore, the calcination of the dried mixture is not particularly limited, but may be at a temperature of 250°C or higher, 300°C or higher, or 350°C or higher, or 1200°C or lower, 1000°C or lower, or 900°C or lower.

[0056] In step (2) of the method for producing compound powder, examples of Ca-containing compounds that can be used as a coating medium for forming a coating layer include, but are not limited to, calcium hydroxide (Ca(OH) ２ ), calcium carbonate (CaCO3) ３ ), calcium chloride (CaCl ２ ), calcium oxide (CaO), calcium nitrate (Ca(NO) ３ ) ２ ), calcium sulfate (CaSO4) ４ ), calcium acetate (Ca(CH) ３ COO) ２ Examples include ionic compounds that can release calcium ions in water, such as ). The proportion (concentration) of the Ca-containing compound in the coating medium is not particularly limited, but may be, for example, 0.05% by mass or more and 10% by mass or less, and preferably 0.1% by mass or more and 5% by mass or less.

[0057] The solvent used in the coating medium (dispersion) usually contains a majority of water, and preferably is substantially all water. The solvent may also contain other solvents such as lower alcohols that are miscible with water. In addition to the Ca-containing compound and solvent, the coating medium may also contain a dispersant (dispersion accelerator). Examples of such dispersants are not particularly limited, but include polycarboxylic acid-based dispersants such as ammonium polycarboxylate, polyacrylic acid-based dispersants, or polysulfonic acid-based dispersants. The dispersant can be used in an amount of, for example, 0.1 parts by mass or more and 1 part by mass or less per 100 parts by mass of the total of the Ca-containing compound and solvent. It is preferable that the Ca-containing compound is more uniformly dispersed in the coating medium. Dispersion operations may be performed by manual or mechanical means. To obtain a uniform dispersion state, ultrasonic dispersion operations may be used.

[0058] The application of a coating medium containing a Ca-containing compound to the surface of substrate particles (a) includes mixing the substrate particles in the coating medium to form a mixture, thoroughly stirring it, then separating the solid and liquid by filtration or the like, and drying if necessary to obtain substrate particles with the Ca-containing compound applied to their surface. The ratio of the Ca-containing compound to the substrate particles is not particularly limited, but from the viewpoint of suppressing ion elution by forming a sufficient coating layer and maintaining negative thermal expansion characteristics, it may be, for example, 0.6% by mass or more and 60% by mass or less, preferably 0.7% by mass or more and 50% by mass or less, 0.8% by mass or more and 40% by mass or less, 0.9% by mass or more and 30% by mass or less, or 1% by mass or more and 20% by mass or less. The stirring of the mixture can usually be done by mechanical means, for example, about 5 minutes or more and 5 hours or less.

[0059] The firing of substrate particles to which a Ca-containing compound obtained by solid-liquid separation after stirring has been applied to the surface can be carried out for a period of time of, for example, 30 minutes to 40 hours, preferably 1 hour to 30 hours, at a temperature of, for example, 300°C to 1500°C, preferably 400°C to 1200°C, more preferably 500°C to 1000°C, from the viewpoint of reliably forming a Ca-containing coating layer.

[0060] The calcined product obtained in this way may be washed by mixing and stirring with pure water, and solid-liquid separation may be performed by removing the supernatant liquid. This washing and solid-liquid separation process may be performed once or multiple times, for example, 3 to 6 times. After these processes, the solid content can be dried at a predetermined temperature (for example, 80°C to 150°C).

[0061] In this way, a compound powder can be obtained which is a composite product comprising base particles and a coating layer formed from a metal compound containing Ca and element A that coats the surface of the base particles. The metal compound containing Ca and element A that constitutes the coating layer may include, for example, a Ca-P-O composite oxide, a Ca-Zn-O composite oxide, a Ca-Cu-O composite oxide, a Ca-Mg-O composite oxide, a Ca-V-O composite oxide, a Ca-Zn-P-O composite oxide, a Ca-Cu-P-O composite oxide, a Ca-Mg-P-O composite oxide, a Ca-V-P-O composite oxide, or a mixture of two or more of these composite oxides. Preferably, the metal compound containing Ca and element A that constitutes the coating layer may include, or be derived from, a metal compound containing Ca, element A, and O (oxygen).

[0062] <Compound Powder According to Preferred Embodiments> In preferred embodiments, the compound powder possesses all of the essentially required properties described above, or any of the preferred properties within that range. In addition, when 2 g of a compound powder sample and 40 ml of pure water are placed in a pressure vessel (e.g., a 100 ml autoclave made of polytetrafluoroethylene resin) at room temperature, sealed, and shaken manually for 1 minute, the sealed pressure vessel is heated at 121°C for 20 hours, then allowed to cool to room temperature, the sealed pressure vessel is opened to remove the treated liquid, solid-liquid separation is performed using a 0.45 μm membrane filter, and the filtrate from which insoluble matter has been removed is used as the test solution for the ion elution test (the same applies in each of the following embodiments), the amount of at least one ion of element A eluted in this test solution may be 3000 ppm by mass or less per 1 g of sample.

[0063] With this compound powder, the amount of at least one ion of element A that dissolves in the above-mentioned ion dissolution test (i.e., the amount of ions that can become impurities in the dissolved substance) is controlled to be below a predetermined upper limit, thereby maintaining the structural stability of the material itself, and consequently, the negative thermal expansion characteristics can be stably exhibited, and the increase in conductivity can be effectively suppressed.

[0064] In a preferred embodiment, the amount of at least one ion of element A eluted in the above ion elution test of the compound powder is preferably 2500 ppm by mass or less, more preferably 2000 ppm by mass or less, even more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 100 ppm by mass or less, and even more preferably 50 ppm by mass or less.

[0065] In a preferred embodiment, the amount of P ions eluted in the above ion elution test of the compound powder may be typically 3000 ppm by mass or less per gram of sample, preferably 2500 ppm by mass or less, more preferably 2000 ppm by mass or less, even more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 100 ppm by mass or less, and even more preferably 50 ppm by mass or less.

[0066] In a preferred embodiment, the amount of at least one ion of element A eluted in the above ion elution test of the compound powder is preferably such that, in addition to the amount of P ions eluted being within the specified range, or if the amount of P ions eluted being outside the specified range, one or more of the following (i) to (iv) are satisfied: (i) The amount of Zn ions eluted in the above ion elution test is 3000 ppm by mass or less per gram of sample, preferably 2500 ppm by mass or less, more preferably 2000 ppm by mass or less, even more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 100 ppm by mass or less, and even more preferably 50 ppm by mass or less; (ii) The amount of Cu ions eluted in the above ion elution test is 3000 ppm by mass or less per gram of sample, preferably 2500 ppm by mass or less, more preferably 2000 ppm by mass or less, even more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 100 ppm by mass or less, and even more preferably 50 ppm by mass or less; (iii) The amount of Mg ions eluted in the above ion elution test is 3000 ppm by mass or less per gram of sample, preferably 2500 ppm by mass or less, more preferably 2000 ppm by mass or less, even more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, even more preferably 50 ppm by mass or less; and (iv) The amount of V ions eluted in the above ion elution test is 3000 ppm by mass or less per gram of sample, preferably 2500 ppm by mass or less, more preferably 2000 ppm by mass or less, even more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 100 ppm by mass or less, and even more preferably 50 ppm by mass or less.Satisfying any one or more of the above (i) to (iv) may include satisfying only (i), satisfying only (ii), satisfying only (iii), satisfying only (iv), satisfying (i) and (ii), satisfying (i) and (iii), satisfying (i) and (iv), satisfying (ii) and (iii), satisfying (ii) and (iv), satisfying (iii) and (iv), satisfying (i), (ii) and (iii), satisfying (i), (ii) and (iv), satisfying (i), (iii) and (iv), satisfying (ii), (iii) and (iv), satisfying (ii), (iii) and (iv), or satisfying (i), (ii), (iii) and (iv).

[0067] <Resin Composition> The compound powder according to any of the above embodiments may be combined with a resin component to constitute a resin composition. The type and amount of resin used in the resin composition are not particularly limited and may be appropriately selected and adjusted to obtain the target negative thermal expansion properties or other desired properties. In this specification, the term "resin composition" is intended to encompass both a composition that partially contains a solvent such as water or an organic solvent used when mixing the components to prepare the resin composition, and a composition that has had the solvent, such as an organic solvent, removed when mixing the components to prepare the resin composition and which can be removed by reduced pressure after preparation.

[0068] Examples of resins, though not particularly limited, include epoxy resins; polyolefin resins such as polyethylene resin and polypropylene resin; polyvinyl resins such as polyvinyl chloride resin and polyvinyl butyral resin; phenolic resins such as polyphenylene sulfide resin and polystyrene resin such as ABS; polyacrylate resins; polyamide resins; polyimide resins; polyamide-imide resins; polyetherimide resins; silicone resins; polycarbonate resins; ester resins or unsaturated polyester resins such as polybutylene terephthalate (PBT resin) and polyethylene terephthalate (PET resin); fluororesins; liquid crystal polymers; polysulfones; polyethersulfones; aromatic polyether ketone resins such as polyetherether ketones; and mixtures of two or more of these. Among these resins, epoxy resins are preferred from the viewpoint of balancing various properties such as rapid curing, mechanical properties, and heat resistance.

[0069] The amount of resin that constitutes the resin composition is not particularly limited, but is usually 5% by mass or more and 95% by mass or less, preferably 10% by mass or more and 80% by mass or less, more preferably 15% by mass or more and 75% by mass or less, or 20% by mass or more and 70% by mass or less, relative to the total amount of the resin composition.

[0070] The resin composition may contain, in addition to compound powders and resin components, at least one inorganic material powder such as silica (silicon dioxide), silicates, titanium dioxide, graphite, sapphire (aluminum oxide), magnesium oxide, calcium oxide, silicon nitride, boron nitride, aluminum nitride, various glass materials, concrete materials, and various ceramic materials. The inorganic material powder may be in crushed form, spherical form, or aggregate form such as fumed silica. The inorganic material powder is preferably spherical in order to reduce the viscosity of the resin composition. For example, if the inorganic material powder is silica, it may be crystalline or amorphous. The total amount of compound powder and inorganic material powder such as silica (if present) in the resin composition is not particularly limited, but is usually 5% to 95% by mass, preferably 10% to 80% by mass, more preferably 15% to 75% by mass, or 20% to 70% by mass, relative to the total amount of the resin composition.

[0071] The resin composition may contain a curing agent in addition to the compound powder and resin components. Any known curing agent can be used, but examples include acid anhydride compounds, phenolic compounds, amine / amide compounds, and active ester compounds. The amount of curing agent included in the resin composition is not particularly limited, but is usually 0.05% to 10% by mass, preferably 0.1% to 5% by mass or 0.5% to 3% by mass, relative to the total amount of the resin composition.

[0072] Examples of acid anhydride compounds that may be included in the resin composition as curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, polypropylene glycol maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Examples of phenolic compounds that may be included in the resin composition as curing agents include dicyclopentadienephenol addition resins, phenol aralkyl resins, naphthol aralkyl resins, triphenylol methane resins, tetraphenylolethane resins, naphthol novolac resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, biphenyl-modified phenolic resins, aminotriazine-modified phenolic resins, and modified products thereof.

[0073] Examples of amine / amide compounds that may be included in the resin composition as curing agents include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, polypropylene glycol diamine, diethylenetriamine, triethylenetetramine, and pentaethylenehexamine; aromatic polyamines such as metaxylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and phenylenediamine; alicyclic polyamines such as 1,3-bis(aminomethyl)cyclohexane, isophoronediamine, and norbornanediamine; and polyamide resins synthesized from dicyandiamide, a dimer of linolenic acid, and ethylenediamine. Examples of active ester compounds that may be included in the resin composition include compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Preferred examples of active ester compounds include those obtained by the condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound (or its halide) with a hydroxy compound and / or a thiol compound. More preferred examples of active ester compounds include those obtained from a carboxylic acid compound or its halide with a phenol compound and / or a naphthol compound. Examples of carboxylic acid compounds constituting such active ester compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc., or their halides.Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, dihydroxydiphenyl ether, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, polyhydroxynaphthylene ether, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, and dicyclopentadiene-phenol addition resins.

[0074] Other additives that may be included in the resin composition include inorganic fillers and fibers other than negative thermal expansion materials, lubricants and release agents such as fatty acid amides, fatty acid esters, and metal salts of fatty acids, ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, and phenyl salicylate compounds, hindered amine stabilizers, phenolic and phosphorus antioxidants, tin-based heat stabilizers, various antistatic agents, lubricity enhancers such as polysiloxanes, various coloring pigments, silane coupling agents, titanium coupling agents, dyes, plasticizers such as waxes and silicone resins, and mixtures of two or more of these. The amount of such other additives in the resin composition is not particularly limited, but from the viewpoint of maintaining the negative thermal expansion properties and other properties of the resin composition, it is usually 5% by mass or less, preferably 3% by mass or less, relative to the total amount of the resin composition.

[0075] The alpha dose of the negative thermal expansion material and resin composition was 0.0200 cph / cm². ２ The following is preferable: By having the alpha radiation dose of the negative thermal expansion material and resin composition within this range, malfunctions caused by current noise generated by alpha radiation can be suppressed when the negative thermal expansion material and resin composition are used as encapsulating materials for semiconductor devices. The alpha radiation dose of the negative thermal expansion material and resin composition is more preferably 0.0150 cph / cm². ２ Further more preferably, 0.0100 cph / cm²２ The following may apply: The alpha dose of the negative thermal expansion material and resin composition is 0.050 cph / cm². ２ It may also be less than 0.020 cph / cm². ２ It may also be less than 0.010 cph / cm². ２ The following is also acceptable.

[0076] In this specification, for measuring the alpha dose, a semiconductor-type trace alpha-ray energy distribution analyzer may be used, or a measurement method using a gas prosional counter type analyzer or an ionization type analyzer based on the international standard JEDEC STANDARD may be used. When using a semiconductor-type trace alpha-ray energy distribution analyzer, for example, the Hitachi "KS-1000" may be used. When using a semiconductor-type trace alpha-ray energy distribution analyzer, alcohol treatment may be performed as a pretreatment. As a more specific measurement method when measuring the alpha dose of a powder sample of a negative thermal expansion material using a semiconductor-type trace alpha-ray energy distribution analyzer, the following procedure may be adopted: (i) Place the sample to be measured (10 g) and ethyl alcohol (25 ml) into a 50 ml beaker and diffuse the beaker in an ultrasonic cleaner for about 1 minute. (ii) Transfer the entire amount of sample in the beaker to the sample stage so that the surface is uniform, and allow to air dry for about 2 hours. (iii) After natural drying, place the sample stage in a vacuum desiccator, start the vacuum pump, and perform vacuum drying for approximately 3 hours or more. (iv) The vacuum-dried sample stage will be used as the sample for trace alpha radiation measurement. (v) Set the sample stage in the chamber of the measuring device and perform measurement for 200 hours. The effective measurement area is 169 cm². ２ The sample size shall be (13 cm x 13 cm). When measuring the alpha dose of a resin composition, the resin composition can be placed directly on the sample stage. The alpha dose shall be the net count value obtained by subtracting the background from the actual measurement result obtained by the above procedure. The surface alpha dose measured in the range of 2.0 to 10 MeV using the above-mentioned Hitachi KS-1000 device may be used as the alpha dose here.

[0077] In measuring alpha dose according to the international standard JEDEC STANDARD, the measurement can be performed by the following procedure: (i) Use a gas flow type alpha dose measuring device. As the sample to be measured, spread powder on a sample base, for example, with a surface area of ​​900 cm². ２ A sample sheet formed into a sheet shape is used. Depending on the device, the sample sheet may be one that fills the maximum measurement area. The sample sheet is placed as a measurement sample in the alpha dose measuring device (gas prosional counter type measuring device or ionization type measuring device), and PR gas is purged into it. The PR gas used conforms to the international standard JEDEC STANDARD. That is, the PR gas used for measurement is a mixture of 90% argon and 10% methane that has been filled into a gas cylinder for more than three weeks, and is a decayed radon (Rn) gas. (ii) After the PR gas is flowed through the alpha dose measuring device in which the sample sheet is placed for 12 hours and left to stand, the alpha dose measurement is performed for 72 hours. (iii) The average alpha dose is measured in "cph / cm²". ２ The alpha radiation dose is calculated as follows: Anomalies (such as counts due to device vibration) are removed from the count for that hour. The following devices are used for the above measurement method: ・Alpha-ray counter: For example, "LACS-4000M" manufactured by Sumika Analysis Center Co., Ltd. ・"Gas flow type alpha-ray measuring device (MODEL-1950)" manufactured by Alpha Science Co., Ltd. ・"Gas Flow Proportional Counter Model 8600A-LB" manufactured by Ordela Co., Ltd. ・"UltraLo-1800" manufactured by XIA Co., Ltd. The alpha radiation dose using this method is measured over a measurement area of ​​1000 cm². ２ From 4000cm ２ This refers to the alpha dose value calculated from the values ​​counted over 72 to 100 hours.

[0078] <Powder mixture> The compound powder according to any of the above embodiments may be combined with silica powder or other thermally conductive powders to form a powder mixture.

[0079] The silica powder that can constitute the powder mixture is not particularly limited as long as it is a particulate material containing silica. The silica powder may be silica. As silica, fused silica or crystalline silica may be used. The silica powder may be, for example, a core-shell type silica powder in which a silica layer is formed around core particles of resin particles or metal particles, or a hollow silica powder. From the viewpoint of fluidity when mixed with a matrix material such as resin, the particle shape of the silica powder or other thermally conductive powder is preferably substantially spherical. Volume cumulative particle size D at 50% cumulative volume measured by laser diffraction scattering particle size distribution analysis of silica powder or other thermally conductive powder ５０ From the same viewpoint as above, the particle size may be, for example, 0.1 μm or more and 10 μm or less, and preferably 0.5 μm or more and 5 μm or less.

[0080] Other thermally conductive powders besides silica powder are not particularly limited and may be any known ones. Examples of other thermally conductive powders include carbon compounds such as graphite and diamond; metal oxides such as aluminum oxide, magnesium oxide, beryllium oxide, titanium oxide, zirconium oxide, and zinc oxide (other than the Ca-containing composite oxides that are the compound powders mentioned above); metal nitrides such as boron nitride, aluminum nitride, and silicon nitride; metal carbides such as boron carbide, aluminum carbide, and silicon carbide; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; metal carbonates such as magnesium carbonate and calcium carbonate; organic polymer calcined products such as acrylonitrile polymer calcined products, furan resin calcined products, cresol resin calcined products, polyvinyl chloride calcined products, sugar calcined products, and charcoal calcined products; composite ferrites of ferrite and Zn ferrite; Fe-Al-Si ternary alloys; metal powders, or mixtures thereof.

[0081] The mass ratio of compound powder to silica powder or other thermally conductive powder in the powder mixture may be, for example, between 1:99 and 100:0, between 20:80 and 100:0, preferably between 30:70 and 95:5, more preferably between 40:60 and 90:10, and even more preferably between 50:50 and 80:20 or between 60:40 and 80:20, from the viewpoint of balancing the effective expression of negative thermal expansion properties and the suppression of manufacturing costs.

[0082] In one embodiment, a powder mixture may be obtained by mixing two or more negative thermal expansion material powders, including the compound powder, and further including silica-containing powder or other thermally conductive powder. In a further embodiment, a powder mixture can be obtained that includes the compound powder and other negative thermal expansion material, wherein the other negative thermal expansion material has a temperature range in which its linear expansion coefficient (α) is less than 0 ppm / K in a temperature range of at least 0°C to 70°C. In a modified embodiment, a mixed material obtained by mixing two or more negative thermal expansion materials can be obtained that has a temperature range in which its linear expansion coefficient (α) is less than 0 ppm / K in a temperature range of at least 0°C to 70°C. Furthermore, in a related modified embodiment, a mixed material can be constructed by mixing two or more negative thermal expansion materials, wherein the mixed material has a temperature range in which the linear expansion coefficient (α) is less than 0 ppm / K in at least a temperature range of 0°C to 70°C, and each of the powders of two or more negative thermal expansion materials has a temperature range in which the linear expansion coefficient (α) is less than 0 ppm / K in at least a temperature range of 0°C to 70°C.

[0083] <Method for Manufacturing Electronic Components> For example, an electronic component can be manufactured by (1) applying a resin composition containing compound powder and resin components according to any of the above embodiments to a first member, (2) applying a second member to the resin composition simultaneously with or after the application of the resin composition to the first member to obtain a component assembly in which the resin composition is sealed between the first and second members, and (3) sealing the space between the first and second members with the resin composition by pressing the component assembly under heat simultaneously with or after obtaining the component assembly. In the manufacture of such an electronic component, a sealing material containing a resin composition containing compound powder and resin components can be applied for sealing the electronic component. Furthermore, in the manufacture of such an electronic component, a sealing material containing a resin composition containing compound powder and resin components can be applied as an underfill for sealing electronic components. That is, in this application, a sealing material for electronic components containing (or formed from) a resin composition containing compound powder and resin components is provided; and an underfill for sealing electronic components containing (or formed from) a resin composition containing compound powder and resin components is also provided. Underfill for electronic component encapsulation can be rephrased as underfill encapsulating material for electronic components.

[0084] The resin composition applied to the first member can be appropriately selected from either a compound powder or a resin composition containing resin components. The first and second members are not particularly limited, as long as the resin composition can be applied to their surfaces and they can withstand pressure bonding under heat. The materials constituting the first and second members may be the same or different. Specific examples of the first and second members include silicon wafers, metal plates, glass plates, heat-resistant resin plates, and electronic components such as semiconductor chips. For example, one of the first and second members may be a silicon wafer on which electrodes are mounted as a circuit board, and the other may be a semiconductor chip on which electrodes are mounted.

[0085] In a preferred embodiment, an electronic component (semiconductor device) can be manufactured by applying a resin composition containing compound powder and resin components as an underfill encapsulant to a circuit board, which is a silicon wafer, a first component; placing a semiconductor chip, which is a second component, on top of the resin composition, which is the underfill encapsulant; and then sealing the semiconductor chip and the circuit board with the resin composition by pressing under heat, thereby simultaneously curing the resin composition and connecting the electrodes formed on the semiconductor chip and the electrodes formed on the circuit board. The heating temperature for pressing under heat is not particularly limited as long as the molten state of the resin constituting the resin composition is maintained. The pressure applied for pressing under heat is not particularly limited as long as the connection between the semiconductor chip and the circuit board can be reliably achieved. Such a thermocompression bonding method is called the NCP (Non-Conductive Paste) method. Advantages of the NCP method include the ability to shorten the process and curing time, and consequently, the possibility of providing a pre-supplied flip-chip bonding process that can be manufactured at low cost and with low energy. Furthermore, this thermocompression bonding method suppresses the generation of unfilled areas (voids) in the encapsulant and allows for a sufficient filling rate, even when the sphericity (perfect sphereness) of the compound powder contained in the resin composition is not high.

[0086] In another preferred embodiment, a film-like semiconductor encapsulant, pre-formed from a resin composition containing compound powder and resin components, is laminated onto a semiconductor chip, which is a first component. Then, the film-like semiconductor encapsulant is pressed against a circuit board, which is a second component, under heating to connect electrodes formed on the semiconductor chip and electrodes formed on the circuit board. Subsequently, the resin composition is heat-cured to manufacture an electronic component (semiconductor device) in which the semiconductor chip is mounted on the circuit board. Similar to the embodiments described above, the heating temperature for pressing under heating is not particularly limited as long as the molten state of the resin constituting the resin composition is maintained. The pressure applied for pressing under heating is not particularly limited as long as a reliable connection between the semiconductor chip and the circuit board can be achieved. Such a thermocompression bonding method is called the NCF (Non-Conductive Film) method. Advantageous of the NCF method is that even when the gap between the semiconductor chip and the substrate is narrow, good bonding can be achieved through reliable sealing with suppressed void generation. Furthermore, this thermocompression bonding method, like the NCP method, can suppress the generation of unfilled areas (voids) in the encapsulant and achieve a sufficient filling rate, even when the sphericity (perfect sphericity) of the compound powder contained in the resin composition is not high.

[0087] In other preferred embodiments, instead of the NCP or NCF methods described above, electronic components (semiconductor devices) can be manufactured by the ACP (Anitropic Conductive Paste) method or ACF (Anitropic Conductive Film) method, which involves mixing predetermined conductive particles with a resin composition containing compound powder and resin components to form an anisotropic conductive adhesive and performing a similar process. The conductive particles are not particularly limited, but examples include metal particles (e.g., nickel or nickel-gold coated composite materials), resin particles such as acrylic resin that are metal-plated (e.g., gold-plated), or particles having an insulating film that breaks or melts upon contact with heat or pressure. The average size of the conductive particles may be, for example, 1 μm to 50 μm. This thermocompression bonding method, like the NCP or NCF methods, can suppress the generation of unfilled areas (voids) in the encapsulant and achieve a sufficient filling rate, even when the sphericity (perfect sphereness) of the compound powder contained in the resin composition is not high.

[0088] The present invention will be described in more detail below with reference to examples. These examples should be understood as merely illustrative and not as limiting the present invention in any way.

[0089] Example 1 (1) Preparation of base material particles containing P, Zn and Mg By dry synthesis method, Zn １．６ Mg ０．４ P ２ O ７ A ceramic powder of base particles represented by was prepared. Specifically, 19.629 g of ZnO, 2.472 g of MgO, and (NH were weighed in stoichiometric ratios.) ４ ) H ２ PO ４34.619 g was mixed in a mortar in the open air. Next, the mixed powder was fired in an electric furnace at 250°C in the open air for 5 hours. Then, the resulting fired product was manually crushed in a mortar in the open air and remixed, and then fired again in an electric furnace at 350°C in the open air for 10 hours. Next, the resulting fired product was crushed using a Force Mill pulverizer for about 30 seconds and remixed, and then fired again in an electric furnace at 900°C in the open air for 10 hours. This fired product was then crushed using a Force Mill pulverizer for about 30 seconds. After that, the powder of the crushed fired product was placed in a plastic container with 1.0 mm diameter zirconia beads and pure water, and the plastic container was set in a rocking shaker manufactured by Seiwa Giken Co., Ltd., and shaken using the rocking shaker for 1 hour. Subsequently, the zirconia beads were separated using a mesh, and then solid-liquid separation was performed using a small centrifuge (Eppendorf Hi-Mac Technologies Co., Ltd.: CT6E). The solid components were dried to a powder at 110°C using a dryer. This powder was then mixed with pure water and allowed to stand until natural sedimentation occurred, followed by washing with decantation. The supernatant was repeatedly washed until its conductivity (measured according to JIS K0130:2008, using the same method as described below) was ≤20 μS / cm, and then the same solid-liquid separation was performed again. The particles after solid-liquid separation were dried at approximately 110°C for 3 hours, and then crushed using a Force Mill for approximately 30 seconds to obtain base particles. The X-ray diffraction patterns of the substrate particles were evaluated using powder X-ray diffraction (XRD) (measurement temperature 295 K, characteristic X-rays of CuKα: wavelength λ = 0.15418 nm) and synchrotron radiation temperature-dependent X-ray diffraction (wavelength λ = 0.06521 nm), and Zn １．６ Mg ０．４ P ２ O ７ The formation of the crystalline structure was confirmed. The average particle size of the obtained substrate particles (cumulative particle size D at 50% cumulative volume, measured by laser diffraction scattering particle size distribution analysis) ５０ The diameter was approximately 5 μm.

[0090] (2) Formation of a coating layer made from an oxide containing Ca and P 0.3 g of Ca(OH) ２ The base particles (Zn) that will be mixed in later. １．６Mg ０．４ P ２ O ７ A dispersion was obtained by ultrasonically dispersing 30 g of ceramic powder (represented by ) with 0.5 g of polycarboxylic acid-based dispersant "SN Dispersant 5468" (manufactured by Sunopco Co., Ltd.), which is approximately 1.7% by mass, in 200 g of pure water. 30 g of the above-mentioned base particles were mixed into this dispersion. In the resulting mixture, Ca(OH) relative to the base particles was measured. ２ The amount was 1% by mass. This mixture was thoroughly stirred mechanically for about 1 hour to obtain a raw material dispersion. This raw material dispersion was separated into solid and liquid by filtration and dried at 150°C for 2 hours to obtain a raw material for calcination. Next, this calcination raw material was calcined at 800°C for 10 hours under atmospheric pressure. Furthermore, after mixing this calcined product with pure water, stirring with a stirrer, solid and liquid separation was performed by removing the supernatant liquid, and after repeating the solid and liquid separation five times by adding water, the mixture was poured into an evaporating dish and the solid components were heated and dried in a hot air dryer at 110°C. This yielded a compound powder which is a composite product containing base particles and a Ca-containing coating layer on its surface.

[0091] Example 2 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 0.6 g (2 mass%) to obtain a raw material dispersion.

[0092] Example 3 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 0.75 g (2.5 mass%) to obtain a raw material dispersion, and the calcination raw materials were calcined at 650°C for 10 hours under atmospheric pressure.

[0093] Example 4 The above base material particles (Zn１．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 1.5 g (5% by mass) to obtain a raw material dispersion.

[0094] Example 5 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 3 g (10 mass%) to obtain a raw material dispersion, and the raw materials for calcination were calcined at 500°C for 10 hours under atmospheric pressure.

[0095] Example 6 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 3 g (10% by mass) to obtain a raw material dispersion.

[0096] Example 7 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 3 g (10 mass%) to obtain a raw material dispersion, and the raw material dispersion was separated into solid and liquid by filtration, dried at 150°C for 2 hours, and then not subjected to calcination, washing, or drying.

[0097] Example 8 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 6 g (20% by mass) to obtain a raw material dispersion.

[0098] Example 9 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 6 g (20% by mass) to obtain a raw material dispersion, and the calcination raw materials were calcined at 600°C for 10 hours under atmospheric pressure.

[0099] Example 10 The above base material particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(OH) for ceramic powder represented by ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was changed to 6 g (20% by mass) to obtain a raw material dispersion, and the calcination raw materials were calcined at 700°C for 10 hours under atmospheric pressure.

[0100] Example 11 Ca(OH) as a Ca-containing compound for forming a coating layer ２ Instead of Ca(CH ３ COO) ２ Using the above base particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(CH) for ceramic powder represented by ３ COO) ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was adjusted to 3 g (10% by mass) to obtain a raw material dispersion, and the raw materials for calcination were calcined at 500°C for 10 hours under atmospheric pressure.

[0101] Example 12 Ca(OH) as a Ca-containing compound for forming a coating layer ２ Instead of Ca(CH ３ COO) ２ Using the above base particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(CH) for ceramic powder represented by ３ COO) ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was adjusted to 3 g (10% by mass) to obtain a raw material dispersion, and the raw materials for calcination were calcined at 650°C for 10 hours under atmospheric pressure.

[0102] Example 13 Ca(OH) as a Ca-containing compound for forming a coating layer ２ Instead of Ca(CH ３ COO) ２ Using the above base particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(CH) for ceramic powder represented by ３ COO) ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount was adjusted to 6 g (20% by mass) to obtain a raw material dispersion, and the raw materials for calcination were calcined at 500°C for 10 hours under atmospheric pressure.

[0103] Example 14 Ca(OH) as a Ca-containing compound for forming a coating layer ２ Instead of Ca(CH ３ COO) ２ Using the above base particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(CH) for ceramic powder represented by ３ COO) ２A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount was adjusted to 9 g (30% by mass) to obtain a raw material dispersion, and the calcination raw materials were calcined at 500°C for 10 hours under atmospheric pressure.

[0104] Example 15 Eggshells (main component: calcium carbonate) with a thin egg membrane (main component: protein) attached to the surface were collected and coarsely ground in a mortar, and then further crushed in a food-grade mixer. The crushed eggshells were passed through a 1 mm mesh sieve to separate the egg membrane (main component: protein) attached to the surface from the shell. The shells (main component: calcium carbonate) remaining after the egg membrane had been separated were dissolved in acetic acid to form a calcium acetate solution. Using this calcium acetate solution, the above-mentioned base particles (Zn １．６ Mg ０．４ P ２ O ７ A ceramic powder represented by was coated. The Ca concentration in the calcium acetate solution was the same as the Ca (CH) of the substrate particles in Example 11. ３ COO) ２ The amount of Ca was adjusted to be equivalent to that of the original. The raw materials for firing were fired at 500°C for 10 hours under atmospheric pressure. Except for these operations, a compound powder was obtained, which is a composite product containing base particles and a Ca-containing coating layer on its surface, in the same manner as in Example 1.

[0105] Example 16 Ca(OH) as a Ca-containing compound for forming a coating layer ２ Instead of Ca(CH ３ COO) ２ Using the above base particles (Zn １．６ Mg ０．４ P ２ O ７ Ca(CH) for ceramic powder represented by ３ COO) ２ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount was adjusted to 3 g (10 mass%) to obtain a raw material dispersion, and the calcination raw material was heat-treated at 80°C for 10 hours under atmospheric pressure.

[0106] Example 17 Ca(OH) as a Ca-containing compound for forming a coating layer ２ Instead, CaMoO ４ Using the above base particles (Zn １．６ Mg ０．４ P ２ O ７ CaMoO (represented by ceramic powder) ４ A compound powder, which is a composite product containing base particles and a Ca-containing coating layer on its surface, was obtained in the same manner as in Example 1, except that the amount of was adjusted to 1.5 g (5% by mass) to obtain a raw material dispersion.

[0107] Comparative Example 1 The above substrate particles (Zn) in Example 1 １．６ Mg ０．４ P ２ O ７ In the preparation of the ceramic powder represented by , base particles were formed by omitting decantation washing and the associated solid-liquid separation. These unwashed base particles are referred to as Comparative Example 1.

[0108] Comparative Example 2 Washed substrate particles (Zn) that have not undergone the coating layer formation treatment. １．６ Mg ０．４ P ２ O ７ The ceramic powder represented by [the formula] was prepared itself for comparison.

[0109] Measurement methods for various physical properties: Volume cumulative particle size D by laser diffraction scattering particle size distribution measurement method １０ , D ５０ and D ９０ Measurement: The samples obtained in each example and comparative example were placed in pure water and dispersed by ultrasonic irradiation (40W, 3 minutes). Then, using a particle size distribution analyzer (Microtrac (product name) MT-3300EXII (model number) manufactured by Microtrac-Bell Co., Ltd.), the cumulative volume particle size D at 10% cumulative volume was measured using the laser diffraction scattering particle size distribution method. １０ Volume cumulative particle size D at a cumulative volume of 50% ５０ , and volume cumulative particle size D at 90% of cumulative volume ９０ We measured it.

[0110] - Measurement of Volume Resistivity The samples obtained in each example and comparative example were compressed at a pressure of 63 MPa using the MCP-PD51 powder resistance measurement system manufactured by Mitsubishi Chemical Analytec Co., Ltd., and their volume resistivity was measured according to the four-terminal method. Samples that exceeded the measurement limit of this device were prepared as pellets by separately compressing them at a pressure of 63 MPa, and measured using the High Resistivity Meter High Resista UX / MCP-HT800 manufactured by Mitsubishi Chemical Analytec Co., Ltd.

[0111] - Measurement of BET specific surface area The BET specific surface area of ​​the samples obtained in each example and comparative example was measured using a specific surface area measuring device (Macsorb (HM model-1201) manufactured by Mountec Co., Ltd.) in accordance with JIS Z 8830:2013 (Method for measuring the specific surface area of ​​powders (solids) by gas adsorption). A mixed gas of helium as the carrier gas and nitrogen as the adsorbate gas was used. The degassing conditions were 300°C for 10 minutes.

[0112] • Compositional Analysis: The composition (atomic ratio) of the samples obtained in each example and comparative example was analyzed using ICP-OES (Inductivity Coupled Plasma Optical Emission Spectrometry). The Agilient 5110 (manufactured by Agilient Technologies) was used as the ICP-OES instrument.

[0113] XRD Peak Observation and Peak Intensity Ratio Measurement: For the samples obtained in each example and comparative example, peaks were observed by scanning with a powder X-ray diffractometer (Rigaku "MiniFlex2") at room temperature using Cu-Kα rays under the following conditions: tube voltage 30kV, tube current 15mA, scanning speed 5° / min, and scanning angle 2θ = 5° to 80°. Other than the above, the operating conditions for powder X-ray diffraction were as follows: ・Slit: DS-SS; 1.25 degrees, RS; 0.3 mm ・Monochromator graphite step: 0.02° ・Counting method: Constant counting method ・X-ray analysis software: PDXL2 Version 2.9.1.0 Using a powder X-ray diffractometer under the above conditions, the XRD peak intensity ratio (-6 0 2) / (0 2 2) and the XRD peak intensity ratio (2 0 - 1) / (0 2 2) were measured at 30°C, 50°C, and 100°C, respectively. Here, the peak intensity of "(-6 0 2)" refers to the peak intensity of the (-6 0 2) plane that appears at diffraction angles 2θ = 29.3 to 29.55°, the peak intensity of "(0 2 2)" refers to the peak intensity of the (0 2 2) plane that appears at diffraction angles 2θ = 29.6 to 29.7°, and the peak intensity of "(2 0 - 1)" refers to the peak intensity of the (2 0 - 1) plane that appears at 30.0 to 30.2°.

[0114] - Method for measuring the dimensional change ratio (ΔL / L) of epoxy resin composition by TMA 3.90 g of the compound powder of each example or the base particles of each comparative example, along with 1.28 g of the epoxy resin main component, 0.23 g of the diluent, and 0.55 g of the curing agent listed below, were mixed (rotation speed: 2000 rpm, time: 30 seconds) and degassed (rotation speed: 2200 rpm, time: 30 seconds or more) using a kneader (Awatori Rentaro ARE-310, manufactured by THINKY). The resulting resin composition was placed in a cylindrical container with a diameter of 10 mm and degassed in a vacuum container. The degassed resin composition was heated in a dryer at 80°C for 1 hour and at 150°C for 3 hours to cure. The cured resin composition was cut to a size of 10 mm (diameter) x 5 mm (height) and processed into tablets (pellets). The dimensional change ratio (ΔL / L) of the resin composition processed into tablets was measured. • Epoxy resin main component: JER-807, JER-806H, JER-806 (manufactured by Mitsubishi Chemical Corporation) • Diluent: YED216M (manufactured by Mitsubishi Chemical Corporation) • Hardener: JER Cure 113 (manufactured by Mitsubishi Chemical Corporation)

[0115] The measurement conditions for the dimensional change ratio (ΔL / L) by TMA were as follows: • Apparatus: TA7000 (Hitachi High-Tech Thermomechanical Analyzer TMA7000 series) • Cycle 1: The sample was heated from 30°C to 150°C in an atmospheric environment at a heating rate of 6°C / min while applying a load of 100 mN. It was then cooled to room temperature while the load remained applied. • Cycle 2: The sample was heated from 30°C to 150°C in an atmospheric environment at a heating rate of 1°C / min.

[0116] - Measurement of eluted ions, pH, and conductivity of the test solution by ion elution test: 2 g of powder sample of the substance to be measured and 40 ml of pure water were placed in a pressure vessel (100 ml autoclave made of polytetrafluoroethylene resin), sealed, and shaken manually for 1 minute. Then, this sealed pressure vessel was heated at 121°C for 20 hours. After allowing it to cool to room temperature, the sealed pressure vessel was opened to remove the treated solution, and solid-liquid separation was performed using a 0.45 μm membrane filter to remove insoluble matter. The filtrate was used as the test solution for the ion elution test. The amount of eluted ions in this test solution was measured using an ICP-OES instrument "Agilient5110" (manufactured by Agilient Technologies), and the pH and conductivity of the test solution were measured using a HORIBA "LAQUA" model "D-200-2".

[0117] XRD Peaks of Examples 1-2, 4, 6, and 8 The compound powders obtained in Examples 1-2, 4, 6, and 8 showed peaks around 2θ = 22.2-22.3°, 22.6-22.7°, 23.1-23.2°, 23.5°, 24.0°, and 25.0°, respectively, when scanned with an X-ray diffractometer. On average, the Ca(OH) content during coating layer formation increased in the order of Examples 1-2, 4, 6, and 8. ２ As the amount increased, the peak intensity generally increased. These peaks are presumed to originate from the Zn-Ca-P-O metal compound, so Ca(OH) ２ It is understood that a thicker coating layer was formed as the quantity increased. Furthermore, in all of the compound powders obtained in Examples 1-2, 4, 6, and 8, the base particles (Zn) were located around 29.9-30.0°. １．６ Mg ０．４ P ２ O ７A peak thought to originate from the ceramic sintered body represented by was observed. Therefore, it was confirmed that the crystalline structure of the substrate particles was maintained even after the Ca-containing coating layer was formed on the substrate particles. In addition, for each of the compound powders obtained in Examples 1-2, 4, 6, and 8, a peak presumed to originate from the Zn-P-O metal compound was also observed around 25.5-26.5°. For further verification, EDX line analysis was performed on the compound powders obtained in Examples 1-2, 4, 6, and 8. At this time, in order to observe only the elements on the very surface, the conditions for EDX line analysis were set to Vacc. = 5kV and Ipor. = 200pA, which are less likely to cause permeation. As a result, Zn, Mg, O, and P were observed from the surface of the compound powder along with Ca.

[0118] Powder properties of compound powders from Examples 1-17 and base particles from Comparative Examples 1-2. Volume resistivity and volume cumulative particle size D were measured for the compound powders from Examples 1-17 and base particles from Comparative Examples 1-2. １０ , D ５０ , D ９０ , and (D ９０ -D １０ ) / D ５０ The BET specific surface area and the compositional analysis results for each element are shown in Table 1 below. From the results shown in Table 1, it can be seen that the volume resistivity of the compound powders of Examples 1 to 17 was increased compared to Comparative Examples 1 to 2, there was no significant difference in particle size distribution, and there was no significant change in the composition excluding Ca. Furthermore, the BET specific surface area of ​​the compound powders of Examples 1 to 2, 4, and 6 was significantly lower compared to Comparative Examples 1 to 2.

[0119]

[0120] Table 2 below shows the XRD peak intensity ratios (-60²) / (0²²) and (20-1) / (0²²) measured for the compound powders of Examples 1 to 17 and the base particles of Comparative Examples 1 to 2 at 30°C, 50°C, and 100°C, respectively. From the results shown in Table 2, it can be seen that there was no significant difference in the rate of change in crystal structure due to temperature increase in the compound powders of Examples 1 to 17 compared with Comparative Examples 1 to 2.

[0121]

[0122] Table 3 below shows the dimensional change ratio (ΔL / L) of the resin pellets of the compound powders of Examples 1 to 17 and the base particles of Comparative Examples 1 to 2 at 30°C, 50°C, and 70°C, as well as the amount of eluted ions, pH, and conductivity of the test solution measured by the ion elution test. From the results shown in Table 3, it can be seen that, with the compound powders of Examples 1 to 17, compared with Comparative Examples 1 to 2, the expansion characteristics of the resin pellets, depending on the temperature, showed either higher negative thermal expansion characteristics or, if they shifted to positive thermal expansion characteristics, were kept to a minimum. Furthermore, from the results in the same table, it can be seen that, with the compound powders of Examples 1 to 17, the elution of Mg, P, and Zn was significantly suppressed compared with Comparative Examples 1 to 2, and consequently, the conductivity was reduced.

[0123]

[0124] The novel compound powder according to the present invention exhibits negative thermal expansion characteristics in a lower temperature range, and is preferably used as a negative thermal expansion material with a higher thermal shrinkage coefficient. This is advantageous because it can further suppress the possibility of misalignment, interfacial delamination, and wire breakage caused by differences in thermal expansion coefficients between materials. Therefore, it is possible to suppress product defects during the manufacture of highly advanced electronic and optical equipment, fuel cells, and sensors, as well as damage and deterioration during repeated use. Furthermore, it is possible to reduce waste during manufacturing and use, and to reduce energy costs. In these respects, the compound powder of the present invention enables the sustainable management and efficient use of natural resources and promotes decarbonization (carbon neutrality) in the manufacture and use of compound powders and electronic equipment.

Claims

1. A compound powder containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, wherein the compound powder is a composite comprising base particles formed from a compound containing element A and O (oxygen), and a coating layer formed from a metal compound containing Ca and element A that coats the surface of the base particles, and having a temperature range in which the coefficient of linear expansion (α) is less than 0 ppm / K in a temperature range of at least 0°C to 70°C, or having a temperature range in which the dimensional change ratio (ΔL / L) is less than 0 in a temperature range of at least 0°C to 70°C, or -0.5 × 10 in a temperature range of at least 30°C to 70°C －３ A compound powder having the following dimensional change ratio (ΔL / L).

2. The compound powder according to claim 1, wherein 2 g of the compound powder sample and 40 ml of pure water are placed in a pressure-resistant container and sealed at room temperature, shaken manually for 1 minute, the sealed pressure-resistant container is heated at 121°C for 20 hours, then allowed to cool to room temperature, the sealed pressure-resistant container is opened to remove the treated liquid, solid-liquid separation is performed using a 0.45 μm membrane filter, and the filtrate obtained by removing insoluble matter is used as the test solution for the ion elution test, and the amount of at least one ion of element A eluted in this test solution is 3000 ppm by mass or less per 1 g of the sample.

3. The compound powder according to claim 2, wherein the amount of element A ions eluted in the ion elution test is 1,000 ppm by mass or less per gram of the sample.

4. The compound powder according to claim 2, wherein the amount of P ions eluted in the ion elution test is 3000 ppm by mass or less per gram of the sample.

5. The compound powder according to claim 2, satisfying one or more of the following: (i) the amount of Zn ions eluted in the ion elution test is 3000 ppm by mass or less per gram of the sample; (ii) the amount of Cu ions eluted in the ion elution test is 3000 ppm by mass or less per gram of the sample; (iii) the amount of Mg ions eluted in the ion elution test is 3000 ppm by mass or less per gram of the sample; and (iv) the amount of V ions eluted in the ion elution test is 3000 ppm by mass or less per gram of the sample.

6. The base particles are of the general formula Zn ２－ｘ Mg ｘ P ２ O ７ A compound powder according to claim 1 or claim 2, comprising an oxide represented by the formula (wherein 0.1 ≤ x ≤ 0.8).

7. The compound powder according to claim 1 or claim 2, wherein the metal compound containing Ca and element A that coats the surface of the base particles comprises a metal compound containing Ca, element A, and O (oxygen).

8. The volume resistivity at 25°C is 1.0 × 10⁻⁶. ９ The compound powder according to claim 1 or claim 2, wherein the particle size is Ω·cm or larger.

9. The compound powder according to claim 1 or claim 2, wherein element A contains P, and the metal compound containing Ca and element A that coats the surface of the base particle contains oxides of Ca and P.

10. The compound containing the elements A and O (oxygen) has the general formula (1) Zn ２－ｘ T ｘ P ２－ｙ A ｙ O ７±δ (T contains at least one element selected from Mg, Ca, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ta, W, and Bi; A contains at least one element selected from Al, Si, V, Ge, and Sn; 0 ≤ x < 2, 0 ≤ y ≤ 2 are satisfied; δ is a value determined so as to satisfy the charge neutrality condition. However, (x, y) = (0, 0) and (0, 2) are excluded.) The compound powder according to claim 1 or claim 2, comprising an oxide represented by the formula.

11. A resin composition comprising the compound powder and resin component according to claim 1 or claim 2.

12. The resin composition according to claim 11, further comprising a curing agent.

13. Alpha dose is 0.0200 cph / cm² ２ The resin composition according to claim 11, which is as follows:

14. A powder mixture comprising the compound powder described in claim 1 or claim 2 and silica powder or other thermally conductive powder.

15. A encapsulant for electronic components comprising the resin composition described in claim 11.

16. An underfill for encapsulating electronic components comprising the resin composition described in claim 11.

17. A method for producing a compound powder containing at least one element A selected from the group consisting of P, Zn, Cu, Mg, and V, comprising the steps of: providing base particles formed from a compound containing element A and O (oxygen); and applying a coating medium containing a Ca-containing compound to the surface of the base particles and firing it to obtain a composite product including a coating layer formed from a metal compound containing Ca and element A, wherein the compound powder has a temperature range in which the coefficient of linear expansion (α) is less than 0 ppm / K in a temperature range of at least 0°C to 70°C, or has a temperature range in which the dimensional change ratio (ΔL / L) is less than 0 in a temperature range of at least 0°C to 70°C, or has a temperature range in which the dimensional change ratio (ΔL / L) is less than 0 in a temperature range of at least 30°C to 70°C. －３ A method for producing the compound powder having the following dimensional change ratio (ΔL / L).

18. The method according to claim 17, wherein 2 g of the compound powder sample and 40 ml of pure water are placed in a pressure-resistant container and sealed at room temperature, shaken manually for 1 minute, the sealed pressure-resistant container is heated at 121°C for 20 hours, then allowed to cool to room temperature, the sealed pressure-resistant container is opened to remove the treated liquid, solid-liquid separation is performed using a 0.45 μm membrane filter, and the filtrate obtained by removing insoluble matter is used as the test solution for the ion elution test, and the amount of at least one ion of element A eluted in this test solution is 3000 ppm by mass or less per 1 g of the sample.

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