Metal oxide particle, method for producing same, filler, composition, cured product, and component

Abstract

Provided are metal oxide particles and the like, from which a cured product and the like that are less likely to cause interfacial peeling between the metal oxide particles and a resin, and that have a low thermal expansion coefficient as well as a low water absorption and dielectric loss tangent can be obtained.　In the metal oxide particles, at least a part of the surface of inorganic particles represented by formula (1) is coated with at least one compound selected from the group consisting of organosilane compounds, phosphonic acid compounds, amine compounds, hydroxy group-containing compounds, and hydrosilane compounds. (1): Zn2-xTxP2-yAyO7 (In formula (1), T includes at least one element selected from Mg, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Ga, Ge, Zr, Mo, Ag, In, Sn, W, and Bi, A includes at least one element selected from Al, Si, V, Sn, and Ge, and 0≤X<2 and 0≤y≤2 are satisfied, but the case of (x, y)=(0, 2) is excluded.)

Description

Metal oxide particles, method for producing the same, filler, composition, cured product and component

[0001] The present invention relates to metal oxide particles, a method for producing the same, a filler, a composition, a cured product and a component.

[0002] Generally, substances thermally expand as temperature increases. In contrast, there also exist materials having the property of decreasing in volume when heat is applied (hereinafter also referred to as "negative thermal expansion materials"). Examples of negative thermal expansion materials include zeolite, zirconium tungstate, β-eucryptite, and metal pyrophosphate compounds. Among these, metal pyrophosphate compounds are known to be particularly excellent in negative thermal expansion properties (see Patent Document 1).

[0003] On the other hand, some cured products such as insulating films used for semiconductor devices, circuit boards and the like are formed from a composite material containing a resin and an inorganic material. In recent years, a high degree of suppression of thermal expansion has been demanded for such cured products, and development of inorganic materials that can further suppress thermal expansion when compounded into resins is expected.

[0004] Japanese Patent Laid-Open No. 2024-100562

[0005] As described above, metal pyrophosphate compounds are materials particularly excellent in negative thermal expansion properties. However, in cured products formed from composite materials in which such a negative thermal expansion material is compounded into a resin, peeling may occur at the interface between the resin and the negative thermal expansion material, and the negative thermal expansion material may not be able to fully exhibit its negative thermal expansion performance.

[0006] An object of the present invention is to provide metal oxide particles in which interfacial peeling between the metal oxide particles and a resin is less likely to occur, and which can provide a cured product or the like having a low coefficient of thermal expansion, a method for producing the same, and a filler, a composition, a cured product and a component using such metal oxide particles.

[0007] The invention made to solve the above problem is metal oxide particles, wherein at least a part of the surface of inorganic particles represented by the following formula (1) is coated with at least one compound selected from the group consisting of an organosilane compound, a phosphonic acid compound, an amine compound, a hydroxy group-containing compound and a hydrosilane compound. Zn２－ｘ T ｘ P ２－ｙ A ｙ O ７ ... (1) (In formula (1), T includes at least one element selected from Mg, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Ga, Ge, Zr, Mo, Ag, In, Sn, W, and Bi. A includes at least one element selected from Al, Si, V, Sn, and Ge. The conditions 0 ≤ x < 2 and 0 ≤ y ≤ 2 are satisfied, except for (x, y) = (0, 2).)

[0008] Another invention made to solve the above problem is a filler containing the metal oxide particles.

[0009] Another invention made to solve the above problems is a composition comprising the filler and at least one resin selected from the group consisting of epoxy resin, phenolic resin, fluororesin, acrylic resin, styrene resin, butadiene resin, polyarylene ether, polyarylene, polycarbonate, polyimide, polyamideimide, polypropylene, polyamide, polyethylene, polyethylene terephthalate, bismaleimide resin, cyanate resin, polyester resin, cycloolefin polymer, cycloolefin copolymer, and cyclic olefin resin.

[0010] Another invention made to solve the above problem is a cured product formed from the composition.

[0011] Another invention made to solve the above problem is a component containing the cured product.

[0012] According to the present invention, metal oxide particles and a method for producing the same can be provided, which make it difficult for interfacial delamination between the metal oxide particles and the resin to occur and can produce cured products with a low coefficient of thermal expansion. Furthermore, fillers, compositions, cured products, and parts using such metal oxide particles can be provided.

[0013] The following describes in detail metal oxide particles and their manufacturing method according to one embodiment of the present invention, as well as fillers, compositions, cured products, and parts using said metal oxide particles.

[0014] Unless otherwise specified, the descriptions of the upper and lower limits of numerical ranges in the present specification allow the upper limit to be either "not more than" or "less than", and the lower limit to be either "not less than" or "more than". In addition, the upper limit value and the lower limit value can be combined arbitrarily from the disclosed numerical values. When a numerical range is indicated using the symbol "~", it means that the numerical range includes the numerical values of the upper limit and the lower limit. For example, "1~6" means "1 or more and 6 or less". The term "main element" refers to the element with the highest content on a molar basis.

[0015] <Metal oxide particles> The metal oxide particles according to one embodiment of the present invention have at least a part of the surface of inorganic particles represented by formula (1) coated with a predetermined compound (coating agent), and have a negative linear expansion coefficient.

[0016] According to the metal oxide particles, interface delamination between the metal oxide particles and a resin is less likely to occur, and a cured product or the like having a low coefficient of thermal expansion (coefficient of linear expansion) can be obtained. In a conventional composite material obtained by mixing a metal pyrophosphate compound and a resin, a cause of interface delamination is the large difference in thermal expansion coefficient between the metal pyrophosphate compound, which is a negative thermal expansion material, and the resin. In contrast, in the metal oxide particles of the present invention, since at least a part of the surface of the inorganic particles, which are negative thermal expansion materials, is coated with a predetermined coating agent, the adhesion to the resin is improved, and interface delamination is less likely to occur. It is considered that due to the presence of such a coating agent, the metal oxide particles exhibit great negative thermal expansion performance when compounded with a resin, and a cured product or the like having a low coefficient of thermal expansion can be obtained. In addition, a cured product or the like obtained by using the metal oxide particles has a good appearance because interface delamination between the resin and the metal oxide particles is less likely to occur. Furthermore, in a varnish containing the metal oxide particles, a resin, and optionally a dispersion medium, the dispersion stability of the metal oxide particles is also good.

[0017] (Inorganic particles) The inorganic particles serving as the core of the metal oxide particles according to one embodiment of the present invention are particles of a compound represented by the following formula (1). In other words, in the metal oxide particles, the compound represented by the following formula (1) is used as a negative thermal expansion material. Zn ２－ｘ T ｘ P ２－ｙ A ｙO ７ ... (1) (In formula (1), T includes at least one element selected from Mg, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Ga, Ge, Zr, Mo, Ag, In, Sn, W, and Bi. A includes at least one element selected from Al, Si, V, Sn, and Ge. The conditions 0 ≤ x < 2 and 0 ≤ y ≤ 2 are satisfied, except for (x, y) = (0, 2).)

[0018] In equation (1), T is Zn ２ P ２ O ７ It is an element that substitutes for part of the Zn in the mixture. T may contain at least one element selected from Mg, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Ga, Ge, Zr, Mo, Ag, In, Sn, W, and Bi as the main element. The total content ratio of Mg, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Ga, Ge, Zr, Mo, Ag, In, Sn, W, and Bi in T is preferably 0.9 or higher in molar ratio, and more preferably 0.99 or higher. T may contain at least one element selected from Mg, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Ga, Ge, Zr, Mo, Ag, In, Sn, W, and Bi.

[0019] T preferably contains at least one selected from the group consisting of Mg, Al, Ti, and Cu, more preferably contains at least Mg, and even more preferably contains both Mg and Al. T may also be at least one selected from the group consisting of Mg, Al, Ti, and Cu.

[0020] In equation (1), x may be greater than 0. The lower limit of x may be 0.05, 0.1, or 0.2. The upper limit of x may be 1.9, 1.5, 1.0, 0.8, or 0.5. Of these, the case where x is greater than 0 and less than or equal to 0.8 is particularly preferred in that it exhibits a particularly large negative coefficient of linear expansion.

[0021] In equation (1), A is Zn ２ P ２ O ７It is an element that substitutes for at least a portion of the P in the mixture. A may contain at least one element selected from Al, Si, V, Sn, and Ge as its main element. The total content ratio of Al, Si, V, Sn, and Ge in A is preferably 0.9 or higher in molar ratio, and more preferably 0.99 or higher. A may contain at least one element selected from Al, Si, V, Sn, and Ge.

[0022] The upper limit of y in equation (1) may be 1, 0.5, 0.3, 0.2, 0.1, or 0.05. y may also be 0.

[0023] The shape of the inorganic particles is not particularly limited and may be spherical, plate-shaped, flaky, whisker-shaped, rod-shaped, filamentous, crushed, or a combination thereof. From the viewpoint of dispersibility, the size of the inorganic particles is preferably submicron to micron-sized, and the shape is preferably close to crushed or spherical.

[0024] The inorganic particles described above can be manufactured by known methods. For example, the inorganic particles are NH ４ H ２ PO ４ These can be obtained by mixing zinc oxide, the oxide of T in formula (1) and the oxide of A in formula (1) in a predetermined ratio and firing the mixture. More specifically, the inorganic particles can be produced, for example, by the method described in Patent Document 1.

[0025] (Coating Agent) The coating agent that coats at least a portion of the surface of the inorganic particles is at least one compound selected from the group consisting of organosilane compounds, phosphonic acid compounds, amine compounds, hydroxyl group-containing compounds, and hydrosilane compounds. These compounds are preferred as coating agents because they can chemically bond with or adsorb to the inorganic particles (functional groups on the surface of the inorganic particles). The presence of such a coating agent on the surface of the inorganic particles makes them less susceptible to the effects of moisture and suppresses dielectric loss tangent.

[0026] The above coating agent (compound) preferably has at least one reactive group selected from the group consisting of hydroxyl group, phenyl group, vinyl group, styryl group, epoxy group, acryloyloxy group, methacryloyloxy group, amino group, mercapto group, isocyanate group, and alkoxy group. These reactive groups are groups that can chemically bond with the resin. Therefore, when such a coating agent has such reactive groups, interfacial delamination between the metal oxide particles and the resin is less likely to occur in the resulting cured product, and the thermal expansion coefficient of the cured product is lower. The above reactive group may be at least one selected from the group consisting of vinyl group, styryl group, acryloyloxy group, methacryloyloxy group, and amino group. The above alkoxy group is preferably an alkoxy group having 1 to 3 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group.

[0027] In particular, when using a resin having a styryl group or a maleimide group, it is preferable that the coating agent (compound) has at least one reactive group selected from the group consisting of vinyl group, styryl group, acryloyloxy group, methacryloyloxy group, and mercapto group. Furthermore, when using a resin having an epoxy group, it is preferable that the coating agent (compound) has at least one reactive group selected from the group consisting of epoxy group, amino group, and isocyanate group.

[0028] The organosilane compound can be any molecule containing a silicon-oxygen bond or a silicon-nitrogen bond, such as dimethylsiloxane, phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, trimethoxy(4-vinylphenyl)silane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 1,2-bis(t Examples of silane coupling agents include dimethoxysilyl)ethane, (3-mercaptopropyl)trimethoxysilane, hexyltrimethoxysilane, 4-(trimethoxysilyl)styrene, and 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane; hexamethyldisilazane; and polymer-type silane coupling agents manufactured by Shin-Etsu Chemical Co., Ltd., such as "KR-513", "X-12-1050", "X-12-972F", "KR-251", "KF-868", "KF-8012", "X-12-1154", "X-22-3701E", and "X-22-162C".

[0029] When using a resin having a styryl group or a maleimide group, organosilane compounds having at least one reactive group selected from the group consisting of a vinyl group, a styryl group, an acryloyloxy group, a methacryloyloxy group, and a mercapto group are preferred, such as vinyltrimethoxysilane, vinyltriethoxysilane, trimethoxy(4-vinylphenyl)silane, 3-methacryloxypropyltrimethoxysilane, (3-mercaptopropyl)trimethoxysilane, "KR-513", and "X-12-1050". Among these, organosilane compounds having at least one reactive group selected from the group consisting of a styryl group and a mercapto group, such as trimethoxy(4-vinylphenyl)silane and (3-mercaptopropyl)trimethoxysilane, are even more preferred from the viewpoint of reactivity.

[0030] When using a resin having epoxy groups, organosilane compounds having at least one reactive group selected from the group consisting of epoxy groups, amino groups, and isocyanate groups, such as 3-glycidoxypropyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane, are preferred, and organosilane compounds having at least one reactive group selected from the group consisting of epoxy groups and amino groups are more preferred.

[0031] Examples of phosphonic acid compounds include vinylphosphonic acid, propene-1-phosphonic acid, propene-2-phosphonic acid, alkylphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid, nitrilotris(methylenephosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid, 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid monoethyl, didodecyl hydrogen phosphate, octadecyl dihydrogen phosphate, vinylphosphonic acid diethyl, phenylphosphonic acid dimethyl, tetraethylmethylenedibis(phosphonic acid), and other compounds having a phosphate group.

[0032] When using a resin having a styryl group or a maleimide group, a phosphonic acid compound having at least one reactive group selected from the group consisting of vinyl groups, styryl groups, acryloyloxy groups, methacryloyloxy groups, and mercapto groups is preferred, and a phosphonic acid compound having a vinyl group is more preferred. When using a resin having an epoxy group, a phosphonic acid compound having at least one reactive group selected from the group consisting of epoxy groups, amino groups, and isocyanate groups is preferred. When using a resin having an epoxy group, 1-hydroxyethane-1,1-diphosphonic acid is also preferred.

[0033] Examples of amine compounds include aliphatic amines such as n-hexylamine, N-methylhexane-1-amine, penta-4-en-1-amine, 5-norbornene-2-methylamine, and (4Z)-hepta-4,6-dien-1-amine; and aromatic amines such as 2-vinylaniline, 4-aminostyrene, N-phenyl-4-vinylaniline, 2-(3-phenylpropa-1-en-2-yl)aniline, 4-(propa-1-en-2-yl)aniline, and 2,2'-bis(trifluoromethyl)benzidine.

[0034] When using a resin having a styryl group or a maleimide group, an amine compound having at least one polymerizable group selected from the group consisting of a vinyl group, a styryl group, an acryloyloxy group, a methacryloyloxy group, and a mercapto group is preferred, and an amine compound having a vinyl group is more preferred. When using a resin having an epoxy group, any amine compound having an amino group can be suitably used, with 2,2'-bis(trifluoromethyl)benzidine being more preferred.

[0035] Examples of hydroxyl group-containing compounds include aliphatic alcohols and phenols. Examples of aliphatic alcohols include 1-hexanol, cyclohexanol, cyclohexylmethanol, 5-hexen-1-ol, 2-cyclohexen-1-ol, CRODA Dimergol 2033, and Preplast 3172. Primary or secondary alcohols are preferred for the aliphatic alcohols. Examples of phenols include 4-vinylphenol and 2-methoxy-4-(2-propenyl)phenol.

[0036] When using a resin having a styryl group or a maleimide group, a hydroxyl group-containing compound having at least one polymerizable group selected from the group consisting of vinyl groups, styryl groups, acryloyloxy groups, methacryloyloxy groups, and mercapto groups, such as 5-hexen-1-ol and 4-vinylphenol, is preferred, and a hydroxyl group-containing compound having a vinyl group is more preferred. When using a resin having an epoxy group, a hydroxyl group-containing compound having at least one polymerizable group selected from the group consisting of epoxy groups, amino groups, and isocyanate groups is preferred. When using a resin having an epoxy group, dimerols such as dimerol 2033 are also preferred.

[0037] Examples of hydrosilane compounds include benzyldimethylsilane, (3-phenylpropyl)silane, dimethyl(4-vinylphenyl)silane, tripropylsilane, 1,4-bis(dimethylsilyl)benzene, 1,1,3,3-tetramethyldisilazane, KF-9901 hydrosilane-modified silicone manufactured by Shin-Etsu Chemical Co., Ltd., methylphenyl-vinyl-silane, and 1,1,3,3-tetramethyl-1-vinyldisiloxane.

[0038] When using a resin having a styryl group or a maleimide group, a hydrosilane compound having at least one reactive group selected from the group consisting of vinyl groups such as dimethyl(4-vinylphenyl)silane and methyl-phenyl-vinyl-silane, styryl groups, acryloyloxy groups, methacryloyloxy groups, and mercapto groups is preferred, and a hydrosilane compound having a vinyl group is more preferred. When using a resin having an epoxy group, a hydrosilane compound having at least one reactive group selected from the group consisting of epoxy groups, amino groups, and isocyanate groups is preferred. When coating the surface of inorganic particles with a hydrosilane compound, a boron catalyst such as trichloroborane, tribromoborane, trifluoroborane, or tris(pentafluorophenyl)borane may be used.

[0039] The lower limit of the content of the coating agent in the metal oxide particles may be 1 part by mass per 100 parts by mass of the inorganic particles, or 5 parts by mass, 10 parts by mass, 20 parts by mass, 30 parts by mass, or 40 parts by mass. The upper limit of the content of the coating agent in the metal oxide particles may be 200 parts by mass per 100 parts by mass of the inorganic particles, or 150 parts by mass, 100 parts by mass, 80 parts by mass, or 60 parts by mass.

[0040] The metal oxide particles can be obtained by coating the inorganic particles with the coating agent, or by reacting the inorganic particles with the coating agent. This process can be carried out wet or dry by mixing and stirring the inorganic particles and the coating agent. The temperature during this process may be, for example, 25°C to 1200°C. The processing time may be, for example, 1 minute to 48 hours.

[0041] The lower limit of the amount of coating agent used when reacting the inorganic particles with the coating agent may be 1 part by mass per 100 parts by mass of the inorganic particles, or 5 parts by mass, 10 parts by mass, 20 parts by mass, 30 parts by mass, or 40 parts by mass. The upper limit of the amount of coating agent used may be 200 parts by mass per 100 parts by mass of the inorganic particles, or 150 parts by mass, 100 parts by mass, 80 parts by mass, or 60 parts by mass.

[0042] The metal oxide particles may be substantially composed only of the inorganic particles and the coating agent. The total content of the inorganic particles and the coating agent in the metal oxide particles may be 80% by mass or more, 90% by mass or more, 95% by mass or more, 97% by mass or more, 99% by mass or more, or 100% by mass.

[0043] (Water absorption rate of metal oxide particles) The metal oxide particles preferably have a water absorption rate of 1.0% or less after being exposed to water at 23°C and 50% humidity for one week. The upper limit of the water absorption rate is more preferably 0.50%, but may be 0.3%, 0.1%, or 0.01%. The lower limit of the water absorption rate may be 0.001%, 0.002%, or 0.003%.

[0044] (Dielectric loss tangent of metal oxide particles (D) ｆ The metal oxide particles are preferably such that the dielectric loss tangent, determined by the 10 GHz cavity resonance method after being left to stand at 23°C and 50% RH for one week, is 0.0060 or less. The upper limit of the dielectric loss tangent is more preferably 0.0060, but may also be 0.0030 or 0.0020. The lower limit of the dielectric loss tangent may be 0.0001, 0.0005 or 0.0010.

[0045] (Coefficient of linear expansion) The metal oxide particles have a negative coefficient of linear expansion. The coefficient of linear expansion of the metal oxide particles in at least a portion of the temperature range from 243K to 573K, determined by the following steps [1] and [2], is α ｆ It is preferable that the coefficient of thermal expansion is -5 ppm / K or less. The upper limit of the temperature range is more preferably 573 K, but may also be 473 K or 373 K. The lower limit of the temperature range may be 243 K, 273 K or 298 K. Coefficient of linear expansion α ｆ The upper limit is more preferably -10 ppm / K, and may be -20 ppm / K or -30 ppm / K. Linear expansion coefficient α ｆ The lower limit may be -150 ppm / K, -120 ppm / K, or -100 ppm / K. [1] Linear expansion coefficient α of a composite material obtained by mixing the above metal oxide particles and resin in a volume ratio of 30:70 in at least a portion of the temperature range from 243 K to 573 K ｃ [2] Based on the following equation (i), the coefficient of linear expansion α ｆ Calculate α. ｆ = (α ｃ -ν ｍ ×α ｍ ) / ν ｆ ... (i) (In equation (i), ν ｍ α is the volume ratio of the resin, ｍ ν is the coefficient of linear thermal expansion of the resin, ｆ α is the volume ratio of metal oxide particles, ｆ α is the coefficient of linear expansion of metal oxide particles, ｃ ν is the coefficient of linear thermal expansion of the composite material, ｍ +ν ｆ (This satisfies the condition = 1.)

[0046] The coefficient of linear expansion α mentioned above ｆ The composite material used to determine the result may contain a polymerization initiator as a component other than the metal oxide particles and resin, to the extent that it does not affect the measurement results. The amount of polymerization initiator in the composite material may be 0.5 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the total content of the metal oxide particles and resin.

[0047] <Filler> The filler according to one embodiment of the present invention includes metal oxide particles according to one embodiment of the present invention. The filler according to one embodiment of the present invention may also be metal oxide particles according to one embodiment of the present invention. The filler according to one embodiment of the present invention may be a mixture of metal oxide particles according to one embodiment of the present invention and other particles. The lower limit of the content of metal oxide particles according to one embodiment of the present invention in the filler is preferably 50% by mass, and may be 60% by mass, 70% by mass, 80% by mass, 90% by mass, 95% by mass, or 99% by mass. The upper limit of the content of metal oxide particles according to one embodiment of the present invention in the filler may be 100% by mass.

[0048] The filler preferably has a negative coefficient of linear expansion. The filler has a coefficient of linear expansion α in at least a portion of the temperature range from 243K to 573K, which is determined by the procedures in [1] and [2] above. ｆ It is preferable that the linear expansion coefficient α of the filler is -5 ppm / K or less. ｆ The upper limit is more preferably -10 ppm / K, and may be -20 ppm / K or -30 ppm / K. The linear expansion coefficient α of the filler. ｆ The lower limit may be -150 ppm / K, -120 ppm / K, or -100 ppm / K.

[0049] This filler can be suitably used as a filler when forming composite materials with resins, etc.

[0050] <Composition> A composition according to one embodiment of the present invention comprises the filler and a resin. A composition according to one embodiment of the present invention may also comprise a resin and a filler according to one embodiment of the present invention. The composition may be a mixture of the resin and the filler. The composition may be a crosslinkable composition. The composition can be produced by mixing the resin and the filler.

[0051] The resin used in the composition may be a thermosetting resin or a thermoplastic resin. Preferably, the resin is at least one selected from the group consisting of epoxy resins, phenolic resins, fluororesins, acrylic resins, styrene resins, butadiene resins, polyarylene ethers, polyarylene, polycarbonate, polyimide, polyamide-imide, polypropylene, polyamide, polyethylene, polyethylene terephthalate, bismaleimide resins, cyanate resins, polyester resins, cycloolefin polymers, cycloolefin copolymers, and cyclic olefin resins. Among these, it is more preferable that the resin be at least one selected from the group consisting of polyarylene ethers, cycloolefin polymers, epoxy resins, bismaleimide resins, and cyanate resins. These can be used individually or in combination.

[0052] The resin used in the composition may be a resin having polymerizable groups or reactive groups. The resin may have at least one group selected from the group consisting of styryl groups, maleimide groups, and epoxy groups, or it may have at least one group selected from the group consisting of styryl groups and epoxy groups.

[0053] The total content of resin and filler in the composition may be 80% by mass or more and 100% by mass or less of the total solid content. The lower limit of the total content may be 90% by mass or 95% by mass. The upper limit of the total content may be 99.9% by mass or 99% by mass.

[0054] The composition of the present invention may contain a resin, and may also contain metals, semiconductors, ceramics, glass, etc. One or more of these can be used.

[0055] The resin content in the composition can be appropriately changed depending on the type of resin, the intended use of the composition, etc., but for example, it is preferably 10% to 99% by mass of the total solids, more preferably 20% to 90% by mass, even more preferably 30% to 80% by mass, and may also be 40% to 70% by mass.

[0056] The filler content in the composition is preferably 1% to 90% by mass of the total solids, more preferably 10% to 80% by mass, even more preferably 20% to 70% by mass, and may also be 30% to 60% by mass. The metal oxide particle content in the composition is preferably 1% to 90% by mass of the total solids, more preferably 10% to 80% by mass, even more preferably 20% to 70% by mass, and may also be 30% to 60% by mass.

[0057] The composition may further contain a polymerization initiator. Conventionally known polymerization initiators can be used. Examples of polymerization initiators include organic peroxides, azo initiators, basic initiators, acid initiators, and acid generators, with organic peroxides being preferred.

[0058] If the composition contains a resin having a styryl group (such as polyarylene ether) and a resin having a maleimide group (such as bismaleimide resin), it is preferable that the composition contains a polymerization initiator together with a coating agent having at least one polymerizable group selected from the group consisting of vinyl group, styryl group, acryloyloxy group, methacryloyloxy group, and mercapto group. In this case, it is preferable to use organic peroxides such as dicumyl peroxide, ditert-butyl peroxide, and 1,1-di(t-butylperoxy)cyclohexane; or azo initiators such as 2,2'-azobis(2,4,4-trimethylpentane) and 2,2'-azobis(N-butyl-2-methylpropionamide) as polymerization initiators.

[0059] If the composition contains a resin having an epoxy group (such as an epoxy resin), it is preferable that the composition contains a polymerization initiator together with a coating agent having at least one polymerizable group selected from the group consisting of epoxy groups, amino groups, and isocyanate groups. In this case, it is preferable to use basic initiators such as dicyandiamide, diaminodiphenylsulfone, 2-ethyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, and DBU salts manufactured by Sunapro Co., Ltd. ("SA102", "SA5002", etc.); or acid generators such as "TA-100" and "IK-1" manufactured by Sunapro Co., Ltd.

[0060] The composition may not contain a polymerization initiator. For example, if the composition contains a thermoplastic resin as a positive thermal expansion material, the composition may not contain a polymerization initiator.

[0061] The content of the polymerization initiator in the composition may be, for example, 0.1 parts by mass or more and 10 parts by mass or 1 part by mass or more and 5 parts by mass, based on 100 parts by mass of the total of the resin and filler.

[0062] The composition may further contain a dispersion medium. The composition may be fluid. The composition may be a paste, varnish, etc. As the dispersion medium, any suitable medium can be selected and used, as long as it disperses or dissolves the other components, does not react with these components, and has appropriate volatility.

[0063] The dispersion medium is not particularly limited and may be an organic dispersion medium such as alcohol, ether, ketone, ester, aliphatic hydrocarbon, aromatic hydrocarbon, amide, lactam, etc., or it may be water. One or more dispersion media may be used.

[0064] The dispersion medium is preferably an organic dispersion medium (organic solvent). The content of the organic dispersion medium in the dispersion medium contained in the composition is preferably 80% by volume or more, more preferably 90% by volume or more, and may be 95% by volume or more, 98% by volume or more, 99% by volume or more, or 100% by volume.

[0065] The dispersion medium preferably contains at least one selected from the group consisting of ketones and aromatic hydrocarbons, and more preferably at least one selected from the group consisting of ketones and aromatic hydrocarbons. Examples of ketones include chain ketones such as methyl ethyl ketone, 2-heptanone, and 3-heptanone, and cyclic ketones such as cyclopentanone and cyclohexanone. Examples of aromatic hydrocarbons include toluene and xylene.

[0066] The content of the dispersion medium in the composition is not particularly limited. The lower limit of the solid content concentration (total of each component excluding the dispersion medium) in the composition is preferably 5% by volume, more preferably 10% by volume, and even more preferably 20% by volume. On the other hand, the upper limit of this solid content concentration is preferably 50% by volume, more preferably 45% by volume, and even more preferably 40% by volume. By setting the solid content concentration within the above range, good dispersibility, stability, and coatability are achieved.

[0067] The composition may not contain a dispersion medium. The composition may also be in the form of a solid, such as a powder or a lump. The composition can be prepared by mixing its components.

[0068] <Cured Product> A cured product according to one embodiment of the present invention is formed from a composition according to one embodiment of the present invention. In other words, a cured product according to one embodiment of the present invention is obtained by curing a composition according to one embodiment of the present invention. The cured product is less prone to interfacial delamination and has a low coefficient of thermal expansion. The shape of the cured product is not particularly limited, but may be, for example, a film. That is, the cured product may be a cured film. The cured product may be an insulator or insulating film used in semiconductor devices, circuit boards, etc. The insulator or insulating film may be an interlayer insulating film, a encapsulant, etc. The cured product can be obtained by curing a composition according to one embodiment of the present invention by heating or the like.

[0069] <Component> A component according to one embodiment of the present invention includes a cured product according to one embodiment of the present invention. This component has a low water absorption rate, a low dielectric loss tangent, a low coefficient of thermal expansion, and suppressed volume change due to temperature changes. This component can be suitably used as various components that are undesirable to change in shape and dimensions due to temperature changes. This component can be used, for example, in electronic components such as semiconductor devices and circuit boards. This component can also be used in precision optical components, mechanical components, and the like.

[0070] The following describes some examples. It should be noted that the following examples are representative examples of the present invention and should not be interpreted as narrowing the scope of the invention.

[0071] [Synthesis Example 1] As raw materials for the synthesis of surface-modified fillers, ZnO (13.02 g), MgO (1.61 g), and NH ４ H ２ PO ４ 23.0 g of powder was weighed. These were mixed in an agate mortar and pestle, and then calcined in an alumina crucible at 800-850°C in air for 6 hours. After calcination, it was removed and mixed again in an agate mortar and pestle, and then calcined in an alumina crucible at 850-900°C in air for 10 hours. The inorganic particles synthesized above (Zn-Mg-P-O: compound where T=Mg, x=0.4, y=0 in formula (1)) (0.90 g), 2-butanone (0.80 g), and trimethoxy(4-vinylphenyl)silane (silane coupling agent 1) (0.045 g) were weighed into a vial. These were dispersed in an ultrasonic generator (UT-107) at room temperature for 5 minutes. Then, a stirring bar was added and the mixture was stirred at 70°C for 24 hours. After filtering the powder from the obtained dispersion using a centrifuge, the mixture was washed and filtered again with 2-butanone, and then vacuum-dried at 80°C to obtain metal oxide particle fillers (surface-modified fillers).

[0072] [Synthesis Example 2] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that 3-methacryloyloxypropyltrimethoxysilane (silane coupling agent 2) was used instead of trimethoxy(4-vinylphenyl)silane.

[0073] [Synthesis Example 3] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that hexyltrimethoxysilane (silane coupling agent 3) was used instead of trimethoxy(4-vinylphenyl)silane.

[0074] [Synthesis Example 4] Synthesis of surface-modified filler Surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that vinylphosphonic acid (phosphonic acid compound) was used instead of trimethoxy(4-vinylphenyl)silane.

[0075] [Synthesis Example 5] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that 4-aminostyrene (amine compound) was used instead of trimethoxy(4-vinylphenyl)silane.

[0076] [Synthesis Example 6] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that 5-hexen-1-ol (hydroxyl group-containing compound) was used instead of trimethoxy(4-vinylphenyl)silane.

[0077] [Synthesis Example 7] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that dimethyl(4-vinylphenyl)silane (a hydrosilane compound) was used instead of trimethoxy(4-vinylphenyl)silane.

[0078] [Synthesis Example 8] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that the amount of trimethoxy(4-vinylphenyl)silane added was changed from 0.045 g to 0.090 g.

[0079] [Synthesis Example 9] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 1, except that the amount of trimethoxy(4-vinylphenyl)silane added was changed from 0.045 g to 0.900 g.

[0080] [Synthesis Example 10] ZnO (13.02 g), MgO (1.61 g), and NH as raw materials for the synthesis of surface-modified fillers. ４ H ２ PO ４ Instead of (23.0g), use ZnO (13.83g), MgO (1.01g), α-Al２ O3 (0.25g) and NH ４ H ２ PO ４ Inorganic particles (Zn-Mg-Al-P-O: a compound in formula (1) where T=Mg, Al, x=0.3, and y=0) were obtained using the same procedure as in Synthesis Example 1, except that (23.0 g) was used. Surface-modified fillers were synthesized using the same procedure as in Synthesis Example 1, except that the above inorganic particles were used.

[0081] [Synthesis Example 11] ZnO (13.02 g), MgO (1.61 g), and NH are the raw materials for the synthesis of surface-modified fillers. ４ H ２ PO ４ Instead of (23.0 g), use ZnO (13.83 g), MgO (1.01 g), CuO (0.40 g) and NH ４ H ２ PO ４ Inorganic particles (Zn-Mg-Cu-P-O: a compound in formula (1) where T=Cu, Mg, x=0.3, and y=0) were obtained using the same procedure as in Synthesis Example 1, except that (23.0 g) was used. Surface-modified fillers were synthesized using the same procedure as in Synthesis Example 1, except that the above inorganic particles were used.

[0082] [Synthesis Example 12] ZnO (13.02 g), MgO (1.61 g), and NH as raw materials for the synthesis of surface-modifying fillers. ４ H ２ PO ４ Instead of (23.0g), use ZnO (13.83g), MgO (1.01g), TiO ２ (0.39 g), and NH ４ H ２ PO ４ Inorganic particles (Zn-Mg-Ti-P-O: a compound in formula (1) where T=Mg, Ti, x=0.3, and y=0) were obtained using the same procedure as in Synthesis Example 1, except that (23.0 g) was used. Surface-modified fillers were synthesized using the same procedure as in Synthesis Example 1, except that the above inorganic particles were used.

[0083] [Synthesis Example 13] As raw materials for the synthesis of surface-modified fillers, ZnO (13.02 g), MgO (1.61 g), and NH ４ H ２ PO ４23.0 g of powder was weighed out. These were mixed in an agate mortar and pestle, and then calcined in an alumina crucible at 800-850°C in air for 6 hours. After calcination, it was removed and mixed again in an agate mortar and pestle, and then calcined in an alumina crucible at 850-900°C in air for 10 hours. The inorganic particles synthesized above (Zn-Mg-P-O: compound with T=Mg, x=0.4, y=0 in formula (1)) (0.90 g), 2-butanone (0.80 g), and N-phenyl-3-aminopropyltrimethoxysilane (silane coupling agent 4) (0.039 g) were weighed into a vial, and the powder was dispersed using an ultrasonic generator (UT-107) at room temperature for 5 minutes. Then a stirring bar was added and the mixture was stirred at room temperature for 24 hours. The obtained dispersion was filtered to separate the powder by suction filtration, then washed and filtered again with 2-butanone, and vacuum dried to obtain a surface-modified filler.

[0084] [Synthesis Example 14] Synthesis of surface-modified filler The surface-modified filler was synthesized using the same procedure as in Synthesis Example 10, except that 0.045 g of trimethoxy(4-vinylphenyl)silane (silane coupling agent 1) was replaced with trimethoxy(4-vinylphenyl)silane (0.80 g).

[0085] [Synthesis Example 15] Synthesis of Surface Modified Filler The surface modified filler was synthesized using the same procedure as in Synthesis Example 10, except that KR-251 (0.80 g) was used instead of trimethoxy(4-vinylphenyl)silane (silane coupling agent 1).

[0086] [Synthesis Example 16] Synthesis of Surface Modified Filler The surface modified filler was synthesized using the same procedure as in Synthesis Example 10, except that KR-251 (0.80 g) was used instead of trimethoxy(4-vinylphenyl)silane (silane coupling agent 1) (0.045 g), and then it was calcined at 1000°C for 10 minutes after vacuum drying.

[0087] [Synthesis Example 17] Synthesis of Surface Modified Filler The surface modified filler was synthesized using the same procedure as in Synthesis Example 10, except that KF-8012 (0.80 g) was used instead of trimethoxy(4-vinylphenyl)silane (silane coupling agent 1) (0.045 g), and then it was calcined at 1000°C for 10 minutes after vacuum drying.

[0088] [Synthesis Example 18] Synthesis of Surface Modified Filler The surface modified filler was synthesized using the same procedure as in Synthesis Example 10, except that X-12-1050 (0.80 g) was used instead of trimethoxy(4-vinylphenyl)silane (silane coupling agent 1) (0.045 g).

[0089] [Synthesis Example 19] Synthesis of Surface Modified Filler The surface modified filler was synthesized using the same procedure as in Synthesis Example 1, except that KR-251 (0.40 g) was used instead of trimethoxy(4-vinylphenyl)silane (silane coupling agent 1) (0.045 g).

[0090] [Synthesis Example 20] Synthesis of Surface Modified Filler The surface modified filler was synthesized using the same procedure as in Synthesis Example 1, except that KR-251 (0.80 g) was used instead of trimethoxy(4-vinylphenyl)silane (silane coupling agent 1) (0.045 g), and then it was calcined at 1000°C for 10 minutes after vacuum drying.

[0091] [Comparative Synthesis Example 1] As raw materials for the synthesis of the unmodified filler, ZnO (13.02 g), MgO (1.61 g), and NH ４ H ２ PO ４ 23.0 g of powder was weighed out. These were mixed in an agate mortar and pestle, and then calcined in an alumina crucible at 800-850°C in air for 6 hours. After calcination, the mixture was removed and mixed again in an agate mortar and pestle, and then calcined in an alumina crucible at 850-900°C in air for 10 hours to obtain inorganic particles (Zn-Mg-P-O: a compound in formula (1) where T=Mg, x=0.4, and y=0). No further surface modification was performed, and these inorganic particles were used as an unmodified filler.

[0092] [Comparative Synthesis Example 2] As raw materials for the synthesis of the unmodified filler, ZnO (13.83 g), MgO (1.01 g), α-Al ２ O ３ (0.25g) and NH ４ H ２ PO ４23.0 g of powder was weighed out. These were mixed in an agate mortar and pestle, and then calcined in an alumina crucible at 800-850°C in air for 6 hours. After calcination, the mixture was removed and mixed again in an agate mortar and pestle, and then calcined in an alumina crucible at 850-900°C in air for 10 hours to obtain inorganic particles (Zn-Mg-Al-P-O: a compound in formula (1) where T=Mg, Al, x=0.3, and y=0). No further surface modification was performed, and these inorganic particles were used as an unmodified filler.

[0093] [Comparative Synthesis Example 3] As raw materials for the synthesis of the unmodified filler, ZnO (13.83 g), MgO (1.01 g), CuO (0.40 g), and NH ４ H ２ PO ４ 23.0 g of powder was weighed out. These were mixed in an agate mortar and pestle, and then calcined in an alumina crucible at 800-850°C in air for 6 hours. After calcination, the mixture was removed and mixed again in an agate mortar and pestle, and then calcined in an alumina crucible at 850-900°C in air for 10 hours to obtain inorganic particles (Zn-Mg-Cu-P-O: a compound in formula (1) where T=Mg, Cu, x=0.3, and y=0). No further surface modification was performed, and these inorganic particles were used as an unmodified filler.

[0094] [Comparative Synthesis Example 4] As raw materials for the synthesis of the unmodified filler, ZnO (13.83 g), MgO (1.01 g), TiO ２ (0.39 g), and NH ４ H ２ PO ４ 23.0 g of powder was weighed out. These were mixed in an agate mortar and pestle, and then calcined in an alumina crucible at 800-850°C in air for 6 hours. After calcination, the mixture was removed and mixed again in an agate mortar and pestle, and then calcined in an alumina crucible at 850-900°C in air for 10 hours to obtain inorganic particles (Zn-Mg-Ti-P-O: a compound in formula (1) where T=Mg, Ti, x=0.3, and y=0). No further surface modification was performed, and these inorganic particles were used as an unmodified filler.

[0095] (Confirmation of the presence or absence of surface modification of fillers) The presence or absence of surface modification of each filler obtained in Synthesis Examples 1-20 and Comparative Synthesis Examples 1-4 was confirmed by the KBr tablet method using infrared absorption spectroscopy (Thermonicolette "FT-IR Avator"). The measurement conditions at this time were a resolution of 4 and 64 scans. In the obtained infrared absorption spectrum, the C-H absorption from the coating agent was 2800-3150 cm⁻¹. －１ If it was observed, it was marked with "○"; if it was not observed, it was marked with "×".

[0096] (Surface Modification Rate of Fillers) For the analysis of the surface modification rate of fillers, TG-DTA was used for the analysis of organic compound coatings, and SEM-EDS was used for the analysis of coatings containing a silicone skeleton. The respective analytical methods are described below. The surface modification rates of the powders obtained in Synthesis Examples 1 to 14 and Comparative Synthesis Examples 1 to 4 were measured using TG-DTA (Thermo Gravimetry-Differential Thermal Analysis) (STA-2500, manufactured by Netsch, at room temperature to 1000°C, under air, 20°C / min) and calculated using the following formula. Surface modification rate (%) = Mass of coating agent ÷ Mass of metal oxide particles × 100 = (Mass loss between 120°C and 1000°C) ÷ (Mass at 1000°C) × 100 The surface modification rates of the powders obtained in synthesis examples 15 to 20 were calculated using the following formula, based on the elemental ratios of zinc and silicon measured by SEM-EDS (Scanning Electron Microscope-Energy Dispersive x-ray Spectroscopy) (PhenomProX, manufactured by PhenomWorld, accelerating voltage 15kV). Surface modification rate (%) = Mass of coating agent ÷ Mass of metal oxide particles × 100 = {(Molar ratio of silicon in EDS / Atomic weight of silicon) ÷ (Mass ratio of silicon contained in 1 g of coating agent)} ÷ {((Molar ratio of zinc in EDS / Atomic weight of zinc) ÷ (Mass ratio of zinc contained in 1 g of metal oxide particles))} × 100 The surface modification rate of the filler is evaluated according to the following criteria, and the results are shown in Tables 1 to 5. S: Surface modification rate 1.0% or more and 10.0% or less A: Surface modification rate 0.1% or more and less than 1.0% B: Surface modification rate 0.01% or more and less than 0.1% C: Surface modification rate less than 0.01% When the surface modification rate is 0.01% or more and less than 0.1% (B rating), or 0.1% or more (A rating and S rating), the effect of moisture can be reduced, and therefore it can be judged that the surface modification rate is good in the present invention.

[0097] (Filler Size and Shape) The size of the fillers was analyzed using a laser diffraction / scattering particle size distribution analyzer (LA-1000S, powder measurement unit, Horiba, Ltd.) and evaluated by the average value of three measurements. The particle size of the fillers obtained in Synthesis Examples 1-20 and Comparative Synthesis Examples 1-4 was approximately 2 μm. The shape of the fillers was measured using a Scanning Electron Microscope (SEM) (PhenomProX, PhenomWorld, accelerating voltage 15 kV), and the particle size of the fillers obtained in Synthesis Examples 1-20 and Comparative Synthesis Examples 1-4 was all fragmented.

[0098] [Examples 1-21 and Comparative Examples 1-5] The compositional resins, fillers obtained in Synthesis Examples 1-20 and Comparative Synthesis Examples 1-4, the polymerization initiator dicumyl peroxide (Perkmyl D) or 1B2PZ, and the dispersion medium (toluene and methyl ethyl ketone (MEK)) were weighed in the mass ratios shown in Tables 1-5. The dispersion medium used was a mixture of toluene and methyl ethyl ketone in a 1:1 volume ratio. The types of resins and fillers used are also shown in Tables 1-5. These were mixed in a mix rotor to obtain each composition (composition varnish) of Examples 1-21 and Comparative Examples 1-5. The solid content concentration in each composition was 30% by volume. The resin:filler volume ratio in each composition varnish was 70:30.

[0099] The raw materials used in the examples and comparative examples are as follows: <Resins> ・Resin 1: Styrene-modified polyphenylene ether with two ends, manufactured by Mitsubishi Gas Chemical Co., Ltd., molecular weight 2200 ・Resin 2: "JER828" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation <Polymerization initiators> ・Parkmyl D (dicumyl peroxide, manufactured by Tokyo Chemical Industry Co., Ltd.) ・1B2PZ (1-Benzyl-2-phenyl-1H-imidazole, manufactured by Shikoku Chemical Holdings Co., Ltd.) <Coating agents> • Silane coupling agent 1 (organosilane compound): Trimethoxy(4-vinylphenyl)silane, manufactured by Tokyo Chemical Industry Co., Ltd. • Silane coupling agent 2 (organosilane compound): 3-methacryloyloxypropyltrimethoxysilane, manufactured by Tokyo Chemical Industry Co., Ltd. • Silane coupling agent 3 (organosilane compound): Hexyltrimethoxysilane, manufactured by Tokyo Chemical Industry Co., Ltd. • Silane coupling agent 4 (organosilane compound): N-phenyl-3-aminopropyltrimethoxysilane, manufactured by Tokyo Chemical Industry Co., Ltd. Sulfonic acid compound: vinylphosphonic acid, manufactured by Tokyo Chemical Industry Co., Ltd.; Amine compound: 4-aminostyrene, manufactured by Tokyo Chemical Industry Co., Ltd.; Hydroxy compound (hydroxyl group-containing compound): 5-hexen-1-ol, manufactured by Tokyo Chemical Industry Co., Ltd.; KR-251: silicone resin manufactured by Shin-Etsu Chemical Co., Ltd.; KF-8012: double-ended amino group modified silicone resin manufactured by Shin-Etsu Chemical Co., Ltd.; X-12-1050: alkoxysilyl group / acryloyloxy group side chain resin manufactured by Shin-Etsu Chemical Co., Ltd. Other raw materials were also purchased commercially and used.

[0100] [Evaluation] (Dispersion stability of the composition varnish) The composition varnish was left to stand at room temperature for 1 hour, and then visually checked for sedimentation. If no sedimentation occurred, it was marked with "○", and if sedimentation was observed, it was marked with "×".

[0101] (Measurement of water absorption rate) The powders obtained in Synthesis Examples 1-20 and Comparative Synthesis Examples 1-4 were left to stand at 23°C and 50% humidity for one week to absorb water. After preparing the filler, its mass was measured, and then it was vacuum dried at 120°C for 3 hours. The mass of the dried filler was measured again. The water absorption rate (%) was calculated using the following formula: Water absorption rate (%) = (Mass of filler after water absorption - Mass of dried filler) ÷ (Mass of dried filler) × 100 and evaluated according to the following criteria. The results are shown in Tables 1-5. S: Water absorption rate 0.001% or more and 0.01% or less A: Water absorption rate greater than 0.01% and 0.1% or less B: Water absorption rate greater than 0.1% and 1.0% or less C: Water absorption rate greater than 1.0%

[0102] (Measurement of Dielectric Loss Tangent) The powders obtained in Synthesis Examples 1-20 and Comparative Synthesis Examples 1-4 were evaluated by measuring the dielectric loss tangent at 10 GHz using the cavity resonance method (resonator for powder measurement of dielectric constant measurement system, manufactured by AET Co., Ltd.) and according to the following criteria. The results are shown in Tables 1-5. S: Dielectric loss tangent 0.0001 or more and 0.0020 or less A: Dielectric loss tangent greater than 0.0020 and 0.0030 or less B: Dielectric loss tangent greater than 0.0030 and 0.0060 or less C: Dielectric loss tangent greater than 0.0060

[0103] (Preparation of cured film) The composition varnish was applied to copper foil (CF-T49A-DS-HD2 (manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.), matte surface) using a baker-type applicator (gap: 100 μm) and dried at 100°C for 5 minutes. Subsequently, it was fired under nitrogen at 200°C for 2 hours to form a copper foil laminate with a cured film of about 50 μm on the copper foil. The obtained copper foil laminate was immersed in a 40% by mass iron chloride solution to remove the copper foil. After that, it was washed with water and oven-dried at 80°C for 30 minutes to obtain a cured film.

[0104] (Evaluation of the appearance of the cured film) When the cured film was prepared as described above, if it did not crack and a self-supporting film was obtained after immersion in a 40% by mass iron chloride solution, it was marked as "○", and if the cured film cracked and a self-supporting film could not be obtained, it was marked as "×".

[0105] (Presence or absence of delamination at the resin-filler interface) The obtained cured film was bent 180° and broken, and cross-sectional observation was performed using a Phenom World desktop SEM (Phenom ProX). When no delamination at the resin-filler interface was observed at 10,000x magnification, it was marked as "○", and when delamination was observed, it was marked as "×".

[0106] (Measurement of the average thermal expansion coefficient of the cured film) The obtained cured film was cut into a test piece (width: 3 mm x length: 2 cm), set in a thermomechanical analyzer (Hitachi High-Tech TMA7100E), and measured under nitrogen heating at 5°C / min and tensile load of 100 mN to determine the average thermal expansion coefficient (ppm / K) between 243 K (-30°C) and 373 K (100°C).

[0107] (Calculation of the linear expansion coefficient (converted value) of the filler in the cured film) The linear expansion coefficient (converted value) of the fillers synthesized in Synthesis Examples 1 to 20 and Comparative Synthesis Examples 1 to 4 was determined by the following procedure. In the "Measurement of the average thermal expansion coefficient of the cured film" above, the linear expansion coefficient α from 243K to 373K of each cured film (composite material) was ｃ The coefficient of linear expansion α was calculated. ｃ Using the value of , the linear expansion coefficient α of the filler is calculated based on equation (i) above. ｆ We sought ν. ｍ = 0.7, ν ｆ We set it to = 0.3. Also, α ｍ The concentration was set to 78 ppm / K in both the case of resin 1 and resin 2.

[0108] The results for each are shown in Tables 1 to 5 below.

[0109]

[0110]

[0111]

[0112]

[0113]

[0114] As shown in Tables 1 to 5, the cured films in Examples 1 to 21 did not exhibit interfacial delamination between the resin and filler, and had low thermal expansion coefficients (average thermal expansion coefficients). In other words, by using the surface-modified fillers (metal oxide particles) obtained in Synthesis Examples 1 to 20, it was possible to obtain cured products with low thermal expansion coefficients. The surface-modified fillers obtained in Synthesis Examples 1 to 20 exhibited a negative linear expansion coefficient (converted value) in the cured product after surface modification. On the other hand, in Comparative Examples 1 to 5, a sufficiently low linear expansion coefficient (converted value) could not be obtained.

Claims

1. Metal oxide particles in which at least a portion of the surface of inorganic particles represented by the following formula (1) is coated with at least one compound selected from the group consisting of organosilane compounds, phosphonic acid compounds, amine compounds, hydroxyl group-containing compounds, and hydrosilane compounds. Zn ２－ｘ T ｘ P ２－ｙ A ｙ O ７ ... (1) (In formula (1), T includes at least one element selected from Mg, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Ga, Ge, Zr, Mo, Ag, In, Sn, W, and Bi. A includes at least one element selected from Al, Si, V, Sn, and Ge. The conditions 0 ≤ x < 2 and 0 ≤ y ≤ 2 are satisfied, except for (x, y) = (0, 2).) 2. The metal oxide particles according to claim 1, wherein the compound has at least one reactive group selected from the group consisting of a hydroxyl group, a phenyl group, a vinyl group, a styryl group, an epoxy group, an acryloyloxy group, a methacryloyloxy group, an amino group, a mercapto group, an isocyanate group, and an alkoxy group.

3. The metal oxide particles according to claim 1, wherein the surface modification rate (%) measured by either TG-DTA analysis or SEM-EDS analysis is 0.01% or more and 10% or less.

4. The metal oxide particles according to claim 1, wherein the water absorption rate (%) at 23°C and 50% humidity is 0.001% or more and 1.0% or less.

5. Dielectric loss tangent (D) at 23°C and 50% humidity ｆ The metal oxide particles according to claim 1, wherein the ratio is 0.0001 or more and 0.0060 or less.

6. The coefficient of linear expansion α in at least a partial temperature range from 243 K to 573 K determined by the following procedure ｆ is -5 ppm / K or less, the metal oxide particles according to claim 1. [1] Determine the coefficient of linear expansion α in at least a partial temperature range from 243 K to 573 K of a composite material obtained by mixing metal oxide particles and a resin at a volume ratio of 30:70 ｃ . [2] Calculate the coefficient of linear expansion α based on the following formula (i) ｆ .  α ｆ = (α ｃ - ν ｍ × α ｍ ) / ν ｆ    ...(i) (In formula (i), ν ｍ is the volume ratio of the resin, α ｍ is the coefficient of linear expansion of the resin, ν ｆ is the volume ratio of the metal oxide particles, α ｆ is the coefficient of linear expansion of the metal oxide particles, α ｃ is the coefficient of linear expansion of the composite material, and ν ｍ + ν ｆ = 1 is satisfied.) 7. The metal oxide particles according to claim 1, wherein the inorganic particles represented by formula (1) satisfy the following ranges: 0 ≤ x < 0.8 and 0 ≤ y ≤ 2 8. A method for producing metal oxide particles according to any one of claims 1 to 7, comprising the steps of: mixing inorganic particles represented by formula (1) with at least one compound selected from the group consisting of organosilane compounds, phosphonic acid compounds, amine compounds, hydroxyl group-containing compounds, and hydrosilane compounds; and calcining the mixture obtained in the above step.

9. A filler comprising metal oxide particles according to any one of claims 1 to 7.

10. A composition comprising the filler described in claim 9 and at least one resin selected from the group consisting of epoxy resin, phenolic resin, fluororesin, acrylic resin, styrene resin, butadiene resin, polyarylene ether, polyarylene, polycarbonate, polyimide, polyamideimide, polypropylene, polyamide, polyethylene, polyethylene terephthalate, bismaleimide resin, cyanate resin, polyester resin, cycloolefin polymer, cycloolefin copolymer, and cyclic olefin resin.

11. The composition according to claim 10, further comprising a polymerization initiator.

12. A cured product formed from the composition described in claim 10.

13. A component comprising the cured product described in claim 12.

Images