Spherical silica particle powder and method for producing spherical silica particle powder

Abstract

The present invention provides an inorganic material having a high dielectric constant and a low dielectric loss tangent. A spherical silica particle powder according to the present invention contains a plurality of spherical element-supporting silica particles. The spherical element-supporting silica particles are particles in which at least one metal element M selected from groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table is supported on spherical silica particles. The spherical silica particle powder contains 10-90 mass% of the metal element M, and has a relative dielectric constant of 7.0-300 and a dielectric loss tangent of 0.02 or less at a frequency of 1 GHz.

Description

Spherical silica particle powder and method for producing spherical silica particle powder

[0001] The present invention relates to a powder of spherical silica particles and a method for producing the powder of spherical silica particles.

[0002] In recent years, with the increase in the amount of information communication in the field of communications, the use of high-frequency band signals has become widespread in electronic devices, communication devices, etc. However, the application of high-frequency band signals to such devices has also caused a problem of increased transmission loss of circuit signals. Therefore, materials with a low dielectric loss tangent are required for use in high-frequency band devices.

[0003] Furthermore, as related electronic materials and components become more highly functional, further miniaturization of devices is also required. Communication devices can be made even smaller if the relative dielectric constant of the antenna material incorporated therein is increased. Therefore, ceramic fillers (inorganic oxide fillers) used in antenna materials and the like are required to have a high dielectric constant and a low dielectric loss tangent (see, for example, Non-Patent Document 1).

[0004] Known ceramic fillers with a relatively high dielectric constant and high versatility include titanium oxide powder, titanates, etc. For example, Patent Document 1 proposes an inorganic oxide powder containing spherical titanium oxide powder and aluminum oxide powder, in which the amount of aluminum in the inorganic oxide powder is 20 to 50,000 ppm by mass.

[0005] International Publication No. 2022 / 249941

[0006] A. K. Tagantsev et al: J. of Electroceramics, 11 (2003) pp. 5-66

[0007] However, although conventionally known ceramic fillers have a high dielectric constant, they also have a high dielectric loss tangent.

[0008] Therefore, an object of the present invention is to provide an inorganic material having a high dielectric constant and a low dielectric loss tangent.

[0009] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by a spherical silica particle powder containing spherical element-supported silica particles in which a specific metal element is supported on spherical silica particles in a specific amount, and have thus completed the present invention.

[0010] One aspect of the present invention relates to a spherical silica particle powder containing a plurality of spherical element-supported silica particles, wherein the spherical element-supported silica particles are spherical silica particles supported with at least one of the following metal elements M, the metal element M being contained in the spherical silica particle powder in an amount of 10 to 90 mass %, and the spherical silica particle powder has a relative dielectric constant of 7.0 to 300 and a dielectric loss tangent of 0.02 or less at a frequency of 1 GHz: M: a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table.

[0011] Another aspect of the present invention relates to a method for producing the spherical silica particle powder, which comprises using a spherical silica precursor obtained by a wet method and causing the silica precursor to support at least one of the following metal elements M: M: a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table.

[0012] Another aspect of the present invention relates to a resin composition containing 5 to 90% by mass of the spherical silica particles.

[0013] Another aspect of the present invention relates to a slurry composition containing 1 to 80% by mass of the spherical silica particle powder.

[0014] The present invention provides a powder of spherical silica particles having a high dielectric constant and a small dielectric loss tangent. When the powder is filled into a resin material as a filler, the powder can provide a resin-formed body with a high dielectric constant and a low dielectric loss tangent. The powder can therefore be suitably used for antennas of radio wave transmitters, etc., and can enable miniaturization of the radio wave transmitters.

[0015] The present invention will be described below, but the present invention is not limited to the examples in the following description. In this specification, the term "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits. In this specification, "spherical silica particle powder" means a powder that is an aggregate of spherical silica particles. In this specification, "mass" is synonymous with "weight."

[0016] A spherical silica particle powder according to an embodiment of the present invention (hereinafter referred to as "this embodiment") comprises a plurality of spherical element-supported silica particles, and the spherical element-supported silica particles are particles in which at least one of the following metal elements M is supported on spherical silica particles, the metal element M being contained in the spherical silica particle powder in an amount of 10 to 90 mass %, and the spherical silica particle powder has a relative dielectric constant of 7.0 to 300 and a dielectric loss tangent of 0.02 or less at a frequency of 1 GHz: M: a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table.

[0017] By including a plurality of spherical element-supported silica particles, each of which supports at least one of the metal elements M, the bulk polarization within the spherical silica particles increases, thereby increasing the dielectric constant. Furthermore, by including 10 to 80 mass % of the metal element M in the spherical silica particle powder, the band gap of the silica base material itself is large, thereby reducing the dielectric loss tangent.

[0018] The metal element M is a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table. Examples of metal elements in Group 2 include magnesium (Mg), calcium (Ca), strontium (Sr), and barium (Ba). Examples of metal elements in Group 3 include scandium (Sc), yttrium (Y), and lanthanoids (lanthanum (La), cerium (Ce), and the like. Examples of metal elements in Group 4 include titanium (Ti) and zirconium (Zr). Examples of metal elements in Group 12 include zinc (Zn) and cadmium (Cd). Examples of metal elements in Group 13 include aluminum (Al) and gallium (Ga). Examples of metal elements in Group 14 include germanium (Ge) and lead (Pb). Examples of metal elements in Group 15 include antimony (Sb) and bismuth (Bi). Among these, metal elements selected from Periods 4 to 6 and Groups 2, 3, 4, 12, 14, and 15 of the periodic table are preferred, with magnesium, calcium, barium, lanthanum, titanium, zirconium, zinc, lead, antimony, and bismuth being more preferred because they are easily available and have relatively low toxicity, and magnesium, calcium, barium, lanthanum, titanium, zirconium, and bismuth being even more preferred from the viewpoint of lower toxicity and the ability to further increase the dielectric constant.

[0019] The metal element M is contained in the spherical silica particle powder in an amount of 10 to 90% by mass. When the content of the metal element M is 10% by mass or more, the dielectric constant of the spherical silica particle powder can be increased, and when the content is 90% by mass or less, the high band gap of the silica base material can be maintained, thereby reducing the dielectric tangent of the spherical silica particle powder. The content of the metal element M in the spherical silica particle powder is preferably more than 10% by mass, more preferably 18% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, particularly preferably 50% by mass or more, and most preferably 60% by mass or more. The upper limit is preferably 80% by mass or less, more preferably 78% by mass or less, even more preferably 75% by mass or less, particularly preferably 70% by mass or less, and most preferably 63% by mass or less.

[0020] The content of the metal element M in the spherical silica particle powder can be measured by adding perchloric acid and hydrofluoric acid to the spherical silica particle powder, igniting the mixture to remove the main component silicon, and then subjecting the mixture to inductively coupled plasma (ICP) emission spectrometry.

[0021] As described above, the spherical silica particle powder of this embodiment contains a plurality of spherical element-supported silica particles in which a metal element M is supported on spherical silica particles, thereby containing the metal element M in the powder. The content of the spherical element-supported silica particles is not particularly limited as long as the content of the metal element M in the spherical silica particle powder is 10 to 90 mass %, but the spherical silica particle powder preferably contains 10 mass % or more of the element-supported silica particles, more preferably 30 mass % or more, and even more preferably 50 mass % or more, and the spherical silica particle powder may be composed of element-supported silica particles (100 mass %).

[0022] Furthermore, the spherical silica particle powder of this embodiment may contain particles other than element-supported silica particles, as long as the powder has a relative dielectric constant of 7.0 to 300 and a dielectric loss tangent of 0.02 or less at a frequency of 1 GHz. For example, the powder may contain spherical silica particles that do not support metal elements, or inorganic particles other than silica, such as alumina, titanium oxide, titanate, or zirconate.

[0023] The silica particles contained in the spherical silica particle powder are spherical, and their sphericity is preferably 0.75 to 1.0. As the sphericity decreases, the specific surface area increases, which tends to increase the dielectric loss tangent, so the sphericity is preferably 0.75 or more. The sphericity is more preferably 0.90 or more, even more preferably 0.93 or more, and the closer to 1.0 the better.

[0024] The sphericity can be expressed as the average value of the ratio (DS / DL) of the minimum diameter (DS) to the maximum diameter (DL) calculated by measuring the maximum diameter (DL) and the minor diameter (DS) perpendicular to the maximum diameter (DL) for each of 100 particles in a photographic projection of a powder of spherical silica particles obtained by photographing with a scanning electron microscope (SEM).

[0025] The spherical silica particle powder of this embodiment has a dielectric dissipation factor of 0.02 or less at a frequency of 1 GHz. When the dielectric dissipation factor of the spherical silica particle powder is 0.02 or less at a frequency of 1 GHz, substrates and sheets with improved high-frequency characteristics can be formed. In particular, when measuring the dielectric dissipation factor and dielectric constant of a powder, the sample space becomes small and measurement accuracy deteriorates at frequencies of 10 GHz or higher, so in the present invention, measurements at a frequency of 1 GHz are used. The dielectric dissipation factor of the spherical silica particle powder is preferably 0.01 or less, more preferably 0.009 or less, even more preferably 0.007 or less, even more preferably 0.005 or less, particularly preferably 0.003 or less, and most preferably 0.001 or less. The smaller the dielectric dissipation factor, the more the transmission loss in the circuit is suppressed, so the lower limit is not particularly limited.

[0026] The spherical silica particle powder of this embodiment has a relative dielectric constant of 7.0 to 300 at a frequency of 1 GHz. When the relative dielectric constant of the spherical silica particle powder at a frequency of 1 GHz is 7.0 or more, the effective wavelength of radio waves in a medium can be sufficiently reduced, and when it is 300 or less, both can be achieved with a low dielectric loss tangent. The relative dielectric constant is more preferably 10 or more, even more preferably 20 or more, and particularly preferably 50 or more. Furthermore, it is more preferably 150 or less, even more preferably 130 or less, particularly preferably 120 or less, and most preferably 100 or less.

[0027] The dielectric loss tangent and relative permittivity are measured using a dedicated device (e.g., Keycom Corporation's "Vector Network Analyzer E5063A") using a perturbation resonator method for particle powders dried according to the method described in the Examples. Specifically, a 15 mm diameter x 40 mm long resin tube is capped on the bottom with tape, filled with dried powder, tapped five times, and then refilled with more powder, repeating this process three times. The top is then capped with tape to obtain a tube uniformly filled with powder. The dielectric loss tangent and relative permittivity are obtained by measuring a blank using an empty 15 mm diameter x 40 mm long resin tube capped with the same mass of tape, followed by measurement of the tube uniformly filled with powder.

[0028] The spherical silica particle powder of this embodiment preferably has a median diameter (d50) of 0.5 to 20 μm. A median diameter of 0.5 μm or more can significantly reduce the dielectric loss tangent. Furthermore, if the median diameter is too large, the particle gauge value will increase, and when a resin composition containing the spherical silica particle powder is formed into, for example, a sheet, the minimum thickness of the sheet will be large. Therefore, the median diameter is preferably 20 μm or less. The median diameter of the spherical silica particle powder is more preferably 0.5 to 10 μm, even more preferably 1 to 10 μm, and particularly preferably 1 to 5 μm.

[0029] The spherical silica particle powder of this embodiment has a 10% particle size (d10), which is the particle size at which the cumulative volume becomes 10% in a volume-based particle size distribution curve, of preferably 0.5 to 5.0 μm, more preferably 1.0 to 5.0 μm, and even more preferably 1.0 to 3.0 μm, from the viewpoints of improving uniform dispersibility in a resin composition and enhancing the interaction between the spherical silica particle powder and the resin.

[0030] The ratio of the median diameter d50 to the 10% particle diameter d10 (d50 / d10) is preferably more than 1.0 and not more than 5.0, more preferably 1.3 to 4.0, and even more preferably 1.5 to 3.0, from the viewpoints of improving uniform dispersibility in the resin composition and enhancing the interaction between the spherical silica particles and the resin.

[0031] The maximum particle diameter (Dmax) of the spherical silica particle powder is preferably 150 times or less, more preferably 100 times or less, even more preferably 50 times or less, and particularly preferably 10 times or less, of the median diameter. If the maximum particle diameter is 150 times or less of the median diameter, defects are unlikely to occur, for example, when a sheet is processed using the spherical silica particle powder. Furthermore, the maximum particle diameter is preferably 1.2 times or more, more preferably 1.5 times or more, and even more preferably 2 times or more, of the median diameter.

[0032] The median diameter is a volume-based cumulative 50% diameter determined using a laser diffraction particle size distribution analyzer (e.g., "MT3300EXII" manufactured by Microtrac Bell Co., Ltd.). That is, the particle size distribution is measured by a laser diffraction / scattering method, a cumulative curve is determined with the total volume of the spherical silica particle powder set to 100%, and the median diameter is the particle diameter at the point on the cumulative curve where the cumulative volume is 50%. The 10% particle diameter and maximum particle diameter can also be obtained by the same measurement as the median diameter.

[0033] In this embodiment, the spherical silica particle powder preferably has a unimodal particle size distribution, which can be confirmed by a single peak in the particle size distribution measured by a laser diffraction / scattering method.

[0034] The specific surface area of ​​the spherical silica particles of this embodiment is 0.1 to 5.0 m ２ / g. ２ When the specific surface area is 5.0 m / g or more, there is sufficient contact point with the resin when the spherical silica particles are contained in the resin composition, and therefore the compatibility with the resin is good. ２ When the specific surface area is 0.1 m / g or less, the dielectric loss tangent can be reduced, and therefore an excellent low dielectric loss tangent can be exhibited even in a resin composition, and further, since the specific surface area is small, the fluidity in the resin composition is improved, and the dispersibility in the resin composition is improved. ２ / g or more, and ２ / g or more is more preferable, and 0.5m ２ / g or more is more preferable, and 5.0m ２ / g or less, and ２ / g or less is more preferable, and 3.5m ２ / g or less is more preferable, and 3.0m ２ / g or less is particularly preferred. ２ It is practically difficult to obtain a value less than 1 / g.

[0035] The specific surface area is determined by a multipoint BET method based on a nitrogen adsorption method using a specific surface area / pore distribution measuring device (for example, a "BELSORP-mini II" manufactured by Microtrac-Bell or a "Tristar II" manufactured by Micromeritics). Specifically, 0.1 g of a sample is filled into a measurement glass cell, and the sample is vacuum-dried at 230°C for 5 hours. After that, the relative pressure range of 0.05 to 0.25 is measured at 11 logarithmically equalized points, and the obtained data is analyzed by the multipoint BET method to obtain the specific surface area.

[0036] The specific surface area A (m ２ / g) and the median diameter d50 (μm), A×d50 is 2.7 to 5.0 μm ２ / g, and more preferably 2.7 to 4.5 μm m ２ / g, and more preferably 2.7 to 4.0 μm m ２ / g. The theoretical value of A × d50 is 2.7 [specific surface area = 6 / (true density of silica 2.2 (g / cm ３ A × d50 is calculated by multiplying the specific surface area by the median diameter d50 (μm) by the average particle size. A smaller value is difficult to achieve in practice. The larger the value of A × d50, the larger the specific surface area per particle size and the larger the dielectric tangent. Therefore, A × d50 is 5.0 μm m ２ / g or less is preferred.

[0037] The spherical silica particles of this embodiment may be treated with a silane coupling agent. Treating the surfaces of the silica particles with a silane coupling agent reduces the amount of silanol groups remaining on the surfaces, making the surfaces hydrophobic, suppressing moisture adsorption and improving dielectric loss. In addition, when the particles are used in a resin composition, they have improved affinity with the resin, improving dispersibility and strength after being formed into a resin film.

[0038] Examples of the silane coupling agent include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, etc. One type of silane coupling agent may be used, or two or more types may be used in combination.

[0039] The amount of the silane coupling agent attached is preferably 0.01 to 5 parts by mass, more preferably 0.02 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass, relative to 100 parts by mass of the spherical silica particle powder. Here, the amount of the silane coupling agent attached is preferably 0.01 part by mass or more, more preferably 0.02 part by mass or more, and even more preferably 0.1 part by mass or more, relative to 100 parts by mass of the spherical silica particle powder, and is preferably 5 parts by mass or less, and more preferably 2 parts by mass or less.

[0040] The fact that the surface of the silica particles has been treated with a silane coupling agent can be confirmed by detecting a peak due to a substituent of the silane coupling agent by IR. The amount of the silane coupling agent attached can be measured by the carbon content.

[0041] (Method for Producing Spherical Silica Particle Powder) The spherical silica particle powder of this embodiment is produced by using a spherical silica precursor obtained by a wet method and causing the silica precursor to support at least one of the following metal elements M: M: a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table.

[0042] The wet method refers to a method that uses a liquid silica source and involves gelling it to obtain the raw material for spherical silica particle powder. By using the wet method, spherical silica particles can be formed, eliminating the need to shape the particles by grinding or other methods, resulting in particles with a small specific surface area. Furthermore, the wet method is less likely to produce particles significantly smaller than the average particle size, and the specific surface area tends to decrease after firing. Furthermore, the wet method makes it easier to control the particle size.

[0043] Examples of wet methods include spraying and emulsion gelation. A preferred emulsion gelation method involves emulsifying a dispersed phase containing a silica precursor with a continuous phase and gelling the resulting emulsion to obtain a spherical silica precursor. A preferred emulsification method involves supplying a dispersed phase containing a silica precursor to a continuous phase through a micropore or porous membrane to produce an emulsion. This produces an emulsion with uniform droplet size, resulting in spherical silica with a uniform particle size. Examples of such emulsification methods include a micromixer method and a membrane emulsification method. For example, the micromixer method is disclosed in International Publication No. 2013 / 062105.

[0044] When the obtained silica precursor has a high water content and the weight loss rate exceeds 10% when dried for 12 hours at 230° C., it is preferable to dry it until the weight loss rate is 10% or less. Examples of drying methods include spray drying, static drying in a dryer, and ventilation treatment with dry air.

[0045] If the silica precursor particles are sintered together to form large agglomerates, they may be crushed. However, if the sintering is too strong, the particles will not become spherical even after crushing, and will be crushed, failing to produce spherical particles.

[0046] Commercially available silica precursors may be used. Examples of spherical silica precursors obtained by a wet method include "Sunsphere H-31," "Sunsphere H-33," "Sunsphere H-51," "Sunsphere H-121," "Sunsphere L-51," and "Sunsphere L-52" from the Sunsphere (registered trademark) series manufactured by AGC Si-Tech Co., Ltd., as well as "HNP-20B" and "SLT-20," also manufactured by AGC Si-Tech Co., Ltd.

[0047] The average pore diameter of the silica precursor is preferably 1.0 to 50.0 nm. When the average pore diameter is 1.0 nm or more, the metal element M can be sufficiently supported, thereby achieving the effects of the present invention. Furthermore, when the average pore diameter of the silica precursor is 50.0 nm or less, the silica particles can be densified (the specific surface area can be reduced) without leaving pores by calcination, thereby reducing the dielectric loss tangent. The average pore diameter is more preferably 2.0 nm or more, even more preferably 3.0 nm or more, and particularly preferably 5.0 nm or more. It is also more preferably 30.0 nm or less, even more preferably 20.0 nm or less, and particularly preferably 15.0 nm or less.

[0048] The average pore diameter is determined by the BJH method based on the nitrogen adsorption method using a specific surface area / pore distribution measuring device (for example, a "BELSORP-mini II" manufactured by Microtrac-Bell or a "Tristar II" manufactured by Micromeritics). Specifically, 0.1 g of a sample is filled into a measurement glass cell, and the sample is vacuum-dried at 230°C for 5 hours. After that, the relative pressure range of 0.05 to 1.0 is measured at 49 logarithmically equalized points, and the obtained data is analyzed by the BJH method to obtain the average pore diameter.

[0049] The specific surface area of ​​the silica precursor is 100 to 1000 m ２ / g. The specific surface area of ​​the silica precursor is preferably 100 m ２ When the amount is 1000m / g or more, the metal element M can be sufficiently supported, and the effect of the present invention can be obtained. ２ When the specific surface area of ​​the silica precursor is 200 m / g or less, the strength of the silica precursor particles is sufficiently high. ２ / g or more is more preferable, and 400m ２ / g or more is more preferable, and 500m ２ / g or more is particularly preferred, and ２ / g or less is more preferable, and ２ / g or less is more preferable, and 650m ２ / g or less is particularly preferred.

[0050] The specific surface area is determined by the method described above.

[0051] The sphericity of the silica precursor is preferably 0.75 or more. When the sphericity is 0.75 or more, the particles are substantially spherical, which allows the specific surface area of ​​the particles to be reduced, and the active surface is not exposed due to the vibration of the particles, so the silica particles can have a low dielectric constant. The sphericity is more preferably 0.90 or more, and particularly preferably 0.93 or more. The closer to a sphere, the more desirable it is, so the most preferred is 1.0.

[0052] The sphericity of the silica precursor is measured by the method described above.

[0053] The median diameter (d50) of the silica precursor is preferably 0.5 to 20 μm. If the median diameter is 0.5 μm or more, the particles can be made spherical even after calcination to reduce the specific surface area, and if the median diameter is 20 μm or less, the particles can be easily used as a filler for resins that are easy to mold. The median diameter is more preferably 1 μm or more, even more preferably 1.5 μm or more, and particularly preferably 2 μm or more, and more preferably 10 μm or less, even more preferably 5 μm or less, and particularly preferably 4 μm or less.

[0054] The median diameter of the silica precursor is measured by the method described above.

[0055] The pore volume (PV) of the silica precursor is preferably 0.1 to 2.0 g / cc. When the pore volume of the silica precursor is 0.1 g / cc or more, the metal element M can be favorably supported, and when it is 2.0 g / cc or less, the amount charged to the container can be sufficiently ensured, improving productivity. The pore volume of the silica precursor is preferably 0.1 g / cc or more, more preferably 0.2 g / cc or more, even more preferably 0.5 g / cc or more, particularly preferably 0.7 g / cc or more, and preferably 2.0 g / cc or less, more preferably 1.7 g / cc or less, even more preferably 1.5 g / cc or less, and particularly preferably 1.3 g / cc or less.

[0056] The pore volume is determined by the BJH method based on the nitrogen adsorption method using a specific surface area / pore distribution measuring device (for example, a "BELSORP-mini II" manufactured by Microtrac-Bell or a "Tristar II" manufactured by Micromeritics). Specifically, 0.1 g of a sample is filled into a measurement glass cell, and the sample is vacuum-dried at 230°C for 5 hours. After that, the relative pressure range of 0.05 to 1.0 is measured at 49 logarithmically equalized points, and the obtained data is analyzed by the BJH method to obtain the pore volume.

[0057] Furthermore, the silica precursor preferably has a weight loss rate of 10% or less when dried at 230°C for 12 hours. If the weight loss rate is 10% or less, sintering of the particles is unlikely to occur when the silica precursor is fired in a state where the particles are in contact with each other, making it easier to obtain spherical silica particle powder. The weight loss rate is more preferably 9% or less, even more preferably 8% or less, and particularly preferably 6% or less. Furthermore, since it is desirable for the weight to remain unchanged even after drying at 230°C for 12 hours, there is no particular lower limit.

[0058] The ignition loss of the silica precursor is preferably 5.0 to 15.0% by mass. The ignition loss is the sum of the mass of water adhering to the silica precursor and the mass of water generated by condensation of silanol groups contained in the silica precursor. When the silica precursor has an appropriate number of silanol groups, condensation proceeds during calcination, making it easier for the silanol groups to be reduced. If the ignition loss is too high, the yield during calcination decreases and productivity deteriorates. Therefore, the ignition loss of the silica precursor is more preferably 13.0% by mass or less, and most preferably 12.0% by mass or less. If the ignition loss is too low, silanol groups are more likely to remain during calcination. Therefore, the ignition loss of the silica precursor is more preferably 6.0% by mass or more, and most preferably 7.0% by mass or more.

[0059] Here, the ignition loss is determined in accordance with JIS K0067:1992 as the mass loss when 1 g of silica precursor is heated and dried at 850° C. for 0.5 hours.

[0060] In the manufacturing method of this embodiment, the metal element M is supported on the silica precursor, but it is preferable to first wash the silica precursor. For example, hydrochloric acid, sulfuric acid, nitric acid, or the like is preferably used for washing. Specifically, when hydrochloric acid is used for washing, the silica precursor is dispersed in an aqueous hydrochloric acid solution, followed by solid-liquid separation, and the cake is washed with water and dried. This removes the alkali content from the silica precursor.

[0061] Next, a metal element M is added to the silica precursor. The metal element M is a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table, and specific and preferred examples thereof are as described above. The metal element M exists in the form of an oxide, hydrate, chloride, nitrate, sulfate, or the like. For example, bismuth (Bi) can be used as bismuth nitrate hydrate, lead (Pb) can be used as lead nitrate, zinc (Zn) can be used as zinc sulfate hydrate, lanthanum (La) can be used as lanthanum nitrate hydrate, titanium (Ti) can be used as titanium sulfate, barium (Ba) can be used as barium nitrate, and antimony (Sb) can be used as antimony chloride.

[0062] The washed silica precursor is added to a solution in which a compound containing a metal element M is dissolved in a solvent, and the reaction is carried out. Examples of the solvent include water, alcohols, acetone, etc. The solvent may be used at room temperature or may be heated.

[0063] The silica precursor and the compound containing the metal element M are preferably mixed in such a ratio that the final spherical silica particle powder contains 10 to 90% by mass of the metal element M, and the compound containing the metal element M is preferably mixed in an amount ranging from 20 to 700 parts by mass per 100 parts by mass of the silica precursor. The content of the compound containing the metal element M is more preferably more than 20 parts by mass, even more preferably 50 parts by mass or more, and particularly preferably 100 parts by mass or more, and is preferably 700 parts by mass or less, more preferably 600 parts by mass or less, per 100 parts by mass of the silica precursor.

[0064] As the mixing means, for example, a mixing device such as an evaporator, a Henschel mixer, or a Nauta mixer can be used.

[0065] The silica precursor and the compound containing the metal element M are thoroughly mixed, dried, and then converted into a powder, which is then calcined. The calcination fixes the metal element M to the voids in the silica precursor, densifies the silica precursor, and reduces the number of silanol groups on the surface. This reduces the dielectric loss tangent of the silica particle powder.

[0066] The heat treatment temperature during firing is preferably 700 to 1600°C. If the treatment temperature is too low, the densification takes a long time, resulting in reduced productivity, while if the temperature is too high, the particles tend to aggregate, resulting in a large particle size in the resin composition. The treatment temperature is preferably 800°C or higher, more preferably 900°C or higher, and more preferably 1500°C or lower, and even more preferably 1400°C or lower.

[0067] The heat treatment time may be adjusted as appropriate depending on the apparatus used, the firing temperature, etc., but is preferably 0.5 to 50 hours, more preferably 1 to 10 hours, for example.

[0068] The atmosphere during the heat treatment may be either an oxygen-containing atmosphere or an oxygen-free atmosphere. For example, the calcination may be performed in an air atmosphere, a hydrogen atmosphere, or a nitrogen atmosphere, and the atmosphere may be appropriately adjusted depending on the transition metal element to be supported.

[0069] The heat treatment method is not particularly limited, but examples thereof include a stationary heat treatment, a rotary kiln heat treatment, and a spray combustion heat treatment.

[0070] Spherical silica particle powder may be weakly sintered after firing, and in such cases, it may be subjected to crushing. Crushing is preferably performed so that the sphericity of the particles does not fall below 0.75 in order to maintain the sphericity and surface area without impairing the effects of the present invention. It is also preferable that the surface area does not increase as a result of the crushing treatment. A significant increase in surface area due to crushing treatment means that some spherical particles have been crushed or that fine damage has occurred on the surface, resulting in the generation of fine powder. An increase in surface area is undesirable because it leads to an increase in viscosity when dispersed in a resin and a deterioration in dielectric loss tangent. Crushing can be performed using a crushing device such as a cyclone mill, jet mill, impact mill, or wonder crusher. Crushing can also be performed using an agate mortar or a vibrating sieve.

[0071] The spherical silica particles after calcination may be surface-treated with a silane coupling agent. This process causes the silanol groups present on the surfaces of the spherical silica particles to react with the silane coupling agent, reducing the number of silanol groups on the surfaces and improving the dielectric loss tangent. Furthermore, the surfaces are hydrophobicized, improving the affinity for resins and improving the dispersibility in resins.

[0072] The conditions for the surface treatment are not particularly limited, and general surface treatment conditions may be used, and a wet treatment method or a dry treatment method may be used. From the viewpoint of uniform treatment, the wet treatment method is preferred.

[0073] Examples of the silane coupling agent used in the surface treatment include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, etc. These may be used alone or in combination of two or more.

[0074] Specific examples of the surface treatment agent include aminosilane coupling agents such as aminopropyl methoxysilane, aminopropyl triethoxysilane, ureidopropyl triethoxysilane, N-phenylaminopropyl trimethoxysilane, and N-2(aminoethyl)aminopropyl trimethoxysilane; epoxysilane coupling agents such as glycidoxypropyl trimethoxysilane, glycidoxypropyl triethoxysilane, glycidoxypropyl methyldiethoxysilane, glycidylbutyltrimethoxysilane, and (3,4-epoxycyclohexyl)ethyltrimethoxysilane; mercaptosilane coupling agents such as mercaptopropyl trimethoxysilane and mercaptopropyl triethoxysilane; silane coupling agents such as methyltrimethoxysilane, vinyltrimethoxysilane, octadecyltrimethoxysilane, phenyltrimethoxysilane, metachloroxypropyltrimethoxysilane, imidazole silane, and triazine silane; and CF ３ (CF ２ ) ７ CH ２ CH ２ Si(OCH ３ ) ３ , C.F. ３ (CF ２ ) ７ CH ２ CH ２ SiCl ３ , C.F. ３ (CF ２ ) ７ CH ２ CH ２ Si(CH ３ ) (OCH ３ ) ２ , C.F. ３ (CF ２ ) ７ CH ２ CH ２ Si(CH ３ ) Cl ２ , C.F. ３ (CF ２ ) ５ CH ２ CH ２ SiCl ３ , C.F. ３ (CF ２ ) ５CH ２ CH ２ Si(OCH ３ ) ３ , C.F. ３ CH ２ CH ２ SiCl ３ , C.F. ３ CH ２ CH ２ Si(OCH ３ ) ３ , C ８ F １７ SO ２ N (C ３ H ７ ) CH ２ CH ２ CH ２ Si(OCH ３ ) ３ , C ７ F １５ CONHCH ２ CH ２ CH ２ Si(OCH ３ ) ３ , C ８ F １７ CO ２ CH ２ CH ２ CH ２ Si(OCH ３ ) ３ , C ８ F １７ -O-CF(CF ３ )CF ２ -O-C ３ H ６ SiCl ３ , C ３ F ７ -O-(CF(CF ３ )CF ２ -O) ２ -CF (CF ３ )CONH-(CH ２ ) ３ Si(OCH ３ ) ３ and organosilazane compounds such as hexamethyldisilazane, hexaphenyldisilazane, trisilazane, cyclotrisilazane, and 1,1,3,3,5,5-hexamethylcyclotrisilazane.

[0075] The amount of the silane coupling agent used for treatment is preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and even more preferably 0.10 parts by mass or more, per 100 parts by mass of the spherical silica particle powder, and is preferably 5 parts by mass or less, and more preferably 2 parts by mass or less.

[0076] Examples of methods for treating with a silane coupling agent include a dry method in which the silane coupling agent is sprayed onto a powder of spherical silica particles, and a wet method in which the powder of spherical silica particles is dispersed in a solvent and then a silane coupling agent is added to cause a reaction.

[0077] (Resin composition and slurry composition) The spherical silica particle powder of this embodiment has good dispersibility in various solvents and is excellent in mixability with resin compositions. The resin composition of this embodiment contains the spherical silica particle powder of this embodiment and a resin. The content of the spherical silica particle powder is preferably 5 to 90 mass% with respect to the entire resin composition. When the content of the spherical silica particle powder is 5 mass% or more, a sufficient dielectric constant increasing effect is obtained, and when it is 90 mass% or less, the mechanical strength of the resin composition can be maintained. From the viewpoint of improving the dielectric constant, the content of the spherical silica particle powder in the resin composition is more preferably 10 mass% or more, and even more preferably 15 mass% or more. From the viewpoint of improving the mechanical strength, it is more preferably 85 mass% or less, even more preferably 80 mass% or less, particularly preferably 75 mass% or less, and most preferably 70 mass% or less.

[0078] Examples of the resin include epoxy resin, silicone resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, fluororesin, polyamide resin such as polyimide resin, polyamideimide resin, and polyetherimide; polyester resin such as polybutylene terephthalate and polyethylene terephthalate; polyphenylene ether resin, polyphenylene sulfide resin, phenol resin, orthodivinylbenzene resin, aromatic polyester resin, polysulfone, liquid crystal polymer, polyethersulfone, polycarbonate, maleimide-modified resin, ABS (acrylonitrile butadiene styrene) resin, AAS (acrylonitrile-acrylic rubber styrene) resin, AES (acrylonitrile ethylene propylene diene rubber styrene) resin, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-ethylene copolymer (ETFE). One or more of these may be used. The dielectric loss tangent of a resin composition also depends on the properties of the resin, so the resin to be used should be selected taking these into consideration.

[0079] The resin preferably contains a thermosetting resin. One type of thermosetting resin may be used alone, or two or more types may be used. Examples of the thermosetting resin include epoxy resin, polyphenylene ether resin, polyimide resin, phenol resin, and orthodivinylbenzene resin. From the viewpoints of adhesion, heat resistance, and the like, the thermosetting resin is preferably an epoxy resin, polyphenylene ether resin, or orthodivinylbenzene resin.

[0080] From the viewpoint of adhesion, dielectric properties, etc., the weight average molecular weight of the thermosetting resin is preferably 1000 to 7000, more preferably 1000 to 5000, and even more preferably 1000 to 3000. The weight average molecular weight is determined using gel permeation chromatography (GPC) in terms of polystyrene.

[0081] From the viewpoints of suppressing uneven distribution of silica particles, reducing water absorption, low dielectric tangent, adhesion, etc., the content of the spherical silica particle powder relative to 100 parts by mass of the thermosetting resin is preferably 10 to 400 parts by mass, more preferably 50 to 300 parts by mass, and even more preferably 70 to 250 parts by mass. In particular, when a high loading of silica particles is desired, the content of the silica particle powder is preferably 80 parts by mass or more, more preferably 90 parts by mass or more. Due to the above-mentioned mechanism of action, the spherical silica particle powder is in a sufficiently wetted and uniformly dispersed state, and is in a state in which it is easy to highly interact with the thermosetting resin. Therefore, even in this composition in which the content is within this range, i.e., this composition in which the loading of the spherical silica particle powder relative to the thermosetting resin is high, both components are easily stabilized, and a molded product with excellent adhesion to the metal substrate layer can be formed.

[0082] The spherical silica particle powder of this embodiment can also be used as a filler for a slurry composition. A slurry composition is a mud-like composition in which the spherical silica particle powder of this embodiment is dispersed in an aqueous or oil-based medium. The content of the spherical silica particle powder is preferably 1 to 80 mass %, more preferably 20 to 80 mass %, even more preferably 40 to 80 mass %, and particularly preferably 50 to 80 mass %, based on the total amount of the slurry composition. By including the spherical silica particle powder in this proportion, the viscosity of the dispersion can be maintained at an appropriate level.

[0083] Examples of oil-based media include acetone, methanol, ethanol, butanol, 2-propanol, 1-propanol, isobutyl alcohol, 1-butanol, 2-butanol, 2-methoxyethanol, 2-ethoxyethanol, 1-methoxy-2-propanol, 2-acetoxy-1-methoxypropane, propyl acetate, isobutyl acetate, butyl acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, N,N-dimethylformamide, methyl isobutyl ketone, N-methylpyrrolidone, n-hexane, n-heptane, cyclohexane, methylcyclohexane, cyclohexanone, and naphtha, which is a mixture. These may be used alone or as a mixture of two or more.

[0084] The resin composition and the slurry composition may contain optional components other than the resin and the medium. Examples of optional components include surfactants, fillers other than silica, etc. A dispersing aid may also be added to improve dispersibility.

[0085] Dispersion treatment of spherical silica particle powder in various compositions can be carried out using dispersing devices used for pigment dispersion, etc. For example, mixers such as Disper, Homomixer, Planetary Mixer, etc., homogenizers (e.g., "Clearmix" manufactured by M Technique, "Filmix" manufactured by PRIMIX, "Abramix" manufactured by Silverson, etc.), paint conditioners (manufactured by Red Devil), colloid mills (e.g., "PUC Colloid Mill" manufactured by PUC, "Colloid Mill MK" manufactured by IKA), cone mills (e.g., "Cone Mill MKO" manufactured by IKA), ball mills, sand mills, etc. Examples of suitable dispersers include media-type dispersers such as a jet mill (e.g., "Dynomill" manufactured by Shinmaru Enterprises, etc.), an attritor, a pearl mill (e.g., "DCP Mill" manufactured by Eirich), and a Coball mill; wet jet mills (e.g., "Genus PY" manufactured by Genus, "Starburst" manufactured by Sugino Machine, "Nanomizer" manufactured by Nanomizer, etc.); media-less dispersers such as "Clear SS-5" manufactured by M Technique Co., Ltd. and "MICROS" manufactured by Nara Kikai Co., Ltd.; and other roll mills and kneaders. Among these, those that do not use grinding media (balls, beads, etc.) are preferred. This is because the use of grinding media raises concerns about contamination from worn media. Specifically, media-less dispersers such as wet jet mills (such as "Genus PY" manufactured by Genus Corporation, "Starburst" manufactured by Sugino Machine Ltd., and "Nanomizer" manufactured by Nanomizer Co., Ltd.), "Clear SS-5" manufactured by M Technique Co., Ltd., and "MICROS" manufactured by Nara Kikai Co., Ltd. are preferred.

[0086] The temperature during dispersion treatment is preferably 0 to 100°C. By performing dispersion treatment within this temperature range, the viscosity of the solvent is maintained at an appropriate level, productivity is maintained, and evaporation of the solvent is suppressed, making it possible to easily control the solid content. The treatment temperature is preferably 0 to 100°C, more preferably 5 to 90°C, and even more preferably 10 to 80°C. Here, the treatment temperature is more preferably 5°C or higher, more preferably 10°C or higher, and more preferably 90°C or lower, and even more preferably 80°C or lower.

[0087] The time for the dispersion treatment may be appropriately set depending on the dispersion device used so as not to cause particle destruction, but is preferably 0.5 to 60 minutes, more preferably 0.5 to 10 minutes, and even more preferably 0.5 to 5 minutes.

[0088] Thereafter, the agglomerates of the spherical silica particles that remain after the dispersion treatment are subjected to wet classification. Examples of wet classification include classification using a sieve or centrifugal force. When using a sieve, classification is preferably performed using a sieve with a mesh size of 100 μm or less. As the sieve, for example, a metal sieve with a dense lattice structure, such as an electroformed sieve, is preferably used.

[0089] The sieve opening is preferably 0.2 to 100 μm, more preferably 0.5 to 75 μm, even more preferably 0.5 to 50 μm, and particularly preferably 1 to 35 μm. Here, the sieve opening is preferably 100 μm or less, more preferably 75 μm or less, even more preferably 50 μm or less, and particularly preferably 35 μm or less, and is preferably 0.2 μm or more, more preferably 0.5 μm or more, and even more preferably 1 μm or more.

[0090] Thereafter, the mixture may be diluted or concentrated as necessary to adjust the concentration to an appropriate level. Concentration methods include evaporation concentration and solid-liquid separation.

[0091] In the method for producing a slurry composition of this embodiment, a silane coupling agent may be added to the mixture of the solvent and the spherical silica particle powder. Examples of the silane coupling agent include the silane coupling agents described above.

[0092] When a resin film is produced using a resin composition containing the spherical silica particle powder of this embodiment, the dielectric loss tangent is preferably 0.005 or less, more preferably 0.004 or less, and even more preferably 0.0035 or less at a frequency of 10 GHz. When the dielectric loss tangent of the resin film at a frequency of 10 GHz is 0.005 or less, the resin film has excellent electrical properties and is therefore expected to be used in electronic devices, communication devices, etc. The smaller the dielectric loss tangent, the more the circuit transmission loss can be suppressed, so the lower limit is not particularly limited.

[0093] Furthermore, when a resin film is produced using the resin composition containing the spherical silica particle powder of this embodiment, the relative dielectric constant thereof at a frequency of 10 GHz is preferably 4.0 to 20.0, with the lower limit being preferably 4.0 or more, more preferably 5.0 or more, and even more preferably 5.5 or more, and the upper limit being more preferably 15.0 or less, even more preferably 12.0 or less, and particularly preferably 8.0 or less. When the relative dielectric constant at a frequency of 10 GHz of the resin film is within this range, the resin film has excellent electrical properties and is therefore expected to be used in electronic devices, communication devices, etc.

[0094] The relative dielectric constant of the resin film can be measured by a perturbation resonator method using a dedicated device (for example, a "Vector Network Analyzer E5063A" manufactured by Keycom Co., Ltd.). The dielectric loss tangent of the resin film can be measured using a split post dielectric resonator (SPDR) (for example, manufactured by Agilent Technologies).

[0095] The spherical silica particle powder of this embodiment can be used as various fillers, and is particularly suitable as a filler for resin compositions used in the production of antenna materials for electronic devices such as personal computers, laptops, and digital cameras, and communication devices such as smartphones and game consoles. Specifically, the silica particle powder of this embodiment is expected to be applied to resin compositions, prepregs, metal foil-clad laminates, printed wiring boards, resin sheets, adhesive layers, adhesive films, solder resists, bump reflow materials, rewiring insulating layers, die bond materials, encapsulants, underfills, mold underfills, and laminated inductors, etc., in order to achieve low dielectric tangent, low transmission loss, low moisture absorption, and improved peel strength.

[0096] As described above, the present invention includes the following configurations <1> to <10>. <1> A spherical silica particle powder containing a plurality of spherical element-supported silica particles, wherein the spherical element-supported silica particles are spherical silica particles carrying at least one of the following metal elements M, and the metal element M is contained in the spherical silica particle powder in an amount of 10 to 90 mass %, and the spherical silica particle powder has a relative dielectric constant of 7.0 to 300 and a dielectric dissipation factor of 0.02 or less at a frequency of 1 GHz. M: a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table. <2> The spherical silica particle powder according to <1>, wherein the median diameter of the spherical silica particle powder is 0.5 to 20 μm. <3> The specific surface area of ​​the spherical silica particle powder is 0.1 to 5.0 m. ２ <4> The spherical silica particle powder according to <1> or <2>, wherein the specific surface area A (m ２ / g) and the median diameter d50 (μm), the product A×d50 is 2.7 to 5.0 μm ２ / g. <5> The spherical silica particle powder according to any one of <1> to <4>, wherein the metal element M is a metal element of Periods 4 to 6 and Groups 2, 3, 4, 12, 14, and 15 of the periodic table. <6> A method for producing the spherical silica particle powder according to any one of <1> to <5>, comprising using a spherical silica precursor obtained by a wet method and causing the silica precursor to support at least one of the following metal elements M: M: a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table. <7> A method for producing the spherical silica particle powder according to <6>, wherein the silica precursor has a pore volume of 0.1 to 2.0 g / cc. <8> The specific surface area of ​​the silica precursor is 100 to 1000 m ２<9> A method for producing the spherical silica particle powder according to <6> or <7>, wherein the spherical silica particle powder has a viscosity of 1000 s / g. <10> A resin composition comprising 5 to 90 mass % of the spherical silica particle powder according to any one of <1> to <5>. <11> A slurry composition comprising 1 to 80 mass % of the spherical silica particle powder according to any one of <1> to <5>.

[0097] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. In the following description, the same components are used. Unless otherwise specified, "parts" and "%" represent "parts by mass" and "% by mass." Examples 1 to 27 and 29 to 31 are working examples, and Examples 28 and 32 are comparative examples.

[0098] The additive compounds used in the following examples are as follows: Bismuth nitrate pentahydrate, lead (II) nitrate, zinc sulfate heptahydrate, lanthanum nitrate hexahydrate, barium nitrate, antimony trichloride, 30% titanium (IV) sulfate solution, tin (II) chloride, zinc chloride, tungsten (VI) chloride: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Calcium nitrate tetrahydrate, strontium nitrate: manufactured by Aldrich

[0099] Test Example 1 (Example 1) As a spherical silica precursor, silica particle powder (Sunsphere H-31, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 3 μm, pore volume (PV) 1.00 g / cc, BET specific surface area 650 m) produced by a wet method was used. ２ / g, oil absorption 150 mL / 100 g) was used. 100 g of spherical silica precursor was dispersed in 1 L of 1 M hydrochloric acid, followed by solid-liquid separation. The resulting cake was washed with 10 L of distilled water and dried in vacuo at 200°C to obtain washed silica particle powder. 100 g of the washed silica particle powder was placed in a container, and a solution of 400 g of bismuth nitrate pentahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) dissolved in 1 L of acetone was added thereto. The solvent was distilled off while rotating using an evaporator, and then the mixture was fired in air at 800°C. The obtained particle powder was pulverized using a Wonder Crusher to obtain 400 g of element-supported silica particle powder 1.

[0100] Examples 2 to 12 Element-supported silica particles 2 to 12 were obtained in the same manner as in Example 1, except that the additive compounds, their amounts, and supporting conditions were changed as shown in Table 1.

[0101] (Example 13) As a spherical silica precursor, silica particle powder produced by a wet method (Sunsphere H-51, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 5 μm, pore volume (PV) 0.8 g / cc, BET specific surface area 700 m) was used. ２ Element-supported silica particle powder 13 was obtained in the same manner as in Example 1, except that an element-supported silica particle powder 13 (amount of silica particles: 1000 kJ / g, oil absorption: 150 mL / 100 g) was used.

[0102] (Example 14) As a spherical silica precursor, silica particle powder produced by a wet method (Sunsphere H-121, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 12 μm, pore volume (PV) 0.8 g / cc, BET specific surface area 680 m) was used. ２ Element-supported silica particle powder 14 was obtained in the same manner as in Example 1, except that an element-supported silica particle powder 14 (1 / g, oil absorption 150 mL / 100 g) was used.

[0103] (Example 15) As a spherical silica precursor, silica particle powder produced by a wet method (Sunsphere H-33, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 4 μm, pore volume (PV) 1.7 g / cc, BET specific surface area 700 m) was used. ２ Element-supported silica particle powder 15 was obtained in the same manner as in Example 1, except that an ion-supported silica particle powder (amount of ion-supported silica particles: 1000 kJ / g, oil absorption: 400 mL / 100 g) was used.

[0104] (Example 16) As a spherical silica precursor, silica particle powder produced by a wet method (Sunsphere L-51, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 5 μm, pore volume (PV) 0.7 g / cc, BET specific surface area 420 m) was used. ２ Element-supported silica particle powder 16 was obtained in the same manner as in Example 1, except that an element-supported silica particle powder 16 (amount of silica particles: 1000 kJ / g, oil absorption: 150 mL / 100 g) was used.

[0105] (Example 17) As a spherical silica precursor, silica particle powder produced by a wet method (Sunsphere L-52, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 5 μm, pore volume (PV) 1.3 g / cc, BET specific surface area 400 m) was used. ２Element-supported silica particle powder 17 was obtained in the same manner as in Example 1, except that an ion-supported silica particle powder (100 mL / 100 g, oil absorption 300 mL / 100 g) was used.

[0106] (Example 18) As a spherical silica precursor, silica particle powder produced by a wet method (Sunsphere H-31, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 4 μm, pore volume (PV) 0.1 g / cc, BET specific surface area 200 m) was used. ２ / g, oil absorption 150 mL / 100 g) was used to obtain washed silica particle powder in the same manner as in Example 1. Subsequently, the washed silica particle powder was air-calcined at 800°C for 1 hour to obtain calcined silica particle powder. 100 g of the calcined silica particle powder was placed in a container, and a solution of 400 g of bismuth nitrate pentahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) dissolved in 1 L of acetone was added thereto. The solvent was distilled off while rotating using an evaporator, and then the mixture was air-calcined at 1240°C. The obtained powder was pulverized using a Wonder Crusher to obtain 400 g of element-supported silica particle powder 18.

[0107] Examples 19 to 23 Element-supported silica particles 19 to 23 were obtained in the same manner as in Example 1, except that the added compounds and their amounts were changed as shown in Table 2.

[0108] (Examples 24 to 27) As a spherical silica precursor, silica particle powder (Sunsphere L-52, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 5 μm, pore volume (PV) 1.3 g / cc, BET specific surface area 400 m) produced by a wet method was used. ２ Element-supported silica particles 24 to 27 were obtained in the same manner as in Example 1, except that an element-supported silica particle powder (24 / 27, oil absorption 300 mL / 100 g, and 100 mL / 100 g) was used, and the added compound, its amount added, and the supporting conditions were changed as shown in Table 2.

[0109] Example 28 Silica particles before supporting a metal element were used for comparison with Examples 1 to 27. As a spherical silica precursor, silica particles (Sunsphere H-31, manufactured by AGC Si-Tech Co., Ltd., median diameter (d50) 3 μm, pore volume (PV) 1.00 g / cc, BET specific surface area 650 m) produced by a wet method were used. ２A spherical silica precursor (100 g, oil absorption 150 mL / 100 g) was used. 100 g of the spherical silica precursor was dispersed in 1 L of 1 M hydrochloric acid, followed by solid-liquid separation. The resulting cake was washed with 10 L of distilled water and vacuum dried at 200°C to obtain washed silica particle powder. The washed silica particle powder was air-calcined at 1200°C for 1 hour, and the resulting particle powder was pulverized using a Wonder Crusher to obtain 100 g of silica particle powder 28.

[0110] The spherical silica particle powders of Examples 1 to 28 were evaluated as follows. The results are shown in Tables 1 and 2.

[0111] "Evaluation" <Dielectric Constant, Dielectric Loss Tangent> Using a dedicated device (Vector Network Analyzer E5063A, manufactured by Keycom Corporation), silica particle powder was measured using a perturbation resonator method at a test frequency of 1 GHz, a test temperature of approximately 24°C, a humidity of approximately 45%, and three measurements. First, the powder was vacuum dried at 150°C. One end of a 15 mm diameter x 40 mm long polytetrafluoroethylene (PTFE) tube was capped with Teflon tape, and the dried powder was filled into the tube. The tube was tapped five times and then further filled with powder. This process was repeated three times. The open end of the tube was capped with Teflon tape to obtain a PTFE tube uniformly filled with powder. A blank measurement was performed using an empty PTFE tube (diameter 15 mm × length 40 mm) of the same mass covered with Teflon tape, and then measurements were performed on the PTFE tube uniformly filled with powder. The results were converted into the relative dielectric constant and dielectric loss tangent using the filling rate of the powder in the container.

[0112] <Measurement of Metal Element Content> Perchloric acid and hydrofluoric acid were added to silica particle powder, and the mixture was ignited to remove the main component silicon, and then the metal element content was measured by inductively coupled plasma (ICP) emission spectrometry.

[0113] <Particle diameter (median diameter)> The median diameter was measured using a laser diffraction particle size distribution measuring device (MT3300EXII manufactured by Microtrac-Bell). The measurement was performed after dispersing the spherical silica particle powder by irradiating it with ultrasonic waves three times for 60 seconds inside the device. The measurement was performed twice for 60 seconds each, and the average value was calculated.

[0114] <Specific Surface Area> The spherical silica particle powder was dried under reduced pressure at 230°C to completely remove moisture, and used as a sample. The specific surface area of ​​this sample was determined by the multi-point BET method using nitrogen gas with an automatic specific surface area and pore distribution measuring device "Tristar II" manufactured by Micromeritics.

[0115]

[0116]

[0117] As shown in Tables 1 and 2, Examples 1 to 27 in which a metal element was supported on silica particles had a higher relative dielectric constant than Example 28, and were particle powders with a high dielectric constant and a low dielectric loss tangent.

[0118] Test Example 2 Example 29 39 parts by mass of polyphenylene ether (OPE-2st 2200, a toluene solution with a solid content of 65%, manufactured by Mitsubishi Gas Chemical Company, Inc.), 21 parts by mass of a hydrogenated styrene-based thermoplastic elastomer (Tuftec (registered trademark) M1913), 10 parts by mass of triallyl isocyanurate, 1 part by mass of α,α'-di(t-butylperoxy)diisopropylbenzene, 5 parts by mass of toluene, and 40 parts by volume of the element-supported silica particle powder 1 produced in Example 1 were weighed out and placed in a plastic bottle, and kneaded using a planetary dispenser to obtain a resin composition.

[0119] Example 30 A resin composition was obtained in the same manner as in Example 29, except that the element-supported silica particle powder 4 prepared in Example 4 was used instead of the element-supported silica particle powder 1.

[0120] Example 31 A resin composition was obtained in the same manner as in Example 29, except that the element-supported silica particle powder 5 prepared in Example 5 was used instead of the element-supported silica particle powder 1.

[0121] Example 32 A resin composition was obtained in the same manner as in Example 29, except that the element-supported silica particle powder 1 was replaced with the silica particle powder 28 prepared in Example 28.

[0122] The resin compositions of Examples 29 to 32 were evaluated as follows. The results are shown in Table 3.

[0123] "Evaluation" <Dielectric constant, dielectric loss tangent> The resin composition was vacuum dried at 120°C, the solvent was removed, and then pulverized using a cutter mill. 5 g of this was weighed into a 10 cm x 10 cm x 0.2 mm mold, and low-profile copper foil (thickness: 18 μm, Rz: 3.5 μm, manufactured by Mitsui Kinzoku Co., Ltd., 3EC-M3-V-18) was laminated on top and bottom and set in a vacuum press. The substrate was evacuated, heated to 200°C at 2.5°C / min under 1 MPa, and held at 200°C for 3 hours to obtain a resin-coated metal substrate. The obtained resin-coated metal substrate was immersed in an etching solution (manufactured by Sanhayato Co., Ltd., H-1000A, ferric chloride aqueous solution) to completely remove the copper foil on one side, and then dried in an oven at 100°C for 10 minutes. The relative permittivity and dielectric loss tangent (measurement frequency: 10 GHz) of the obtained pressed prepreg were measured using a vertical split post dielectric resonator (manufactured by Agilent Technologies).

[0124]

[0125] As shown in Table 3, the resin compositions of Examples 29 to 31 had a dielectric constant that was at least twice as high as that of Example 32, and a smaller dielectric loss tangent. The spherical silica particle powder of the present invention was able to exhibit a high dielectric constant and a low dielectric loss tangent among resin compositions.

[0126] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made thereto without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-028874) filed on February 28, 2024, the contents of which are incorporated herein by reference.

Claims

1. A spherical silica particle powder containing a plurality of spherical element-supported silica particles, wherein the spherical element-supported silica particles are spherical silica particles carrying at least one of the following metal elements M, the metal element M being contained in the spherical silica particle powder in an amount of 10 to 90 mass %, and the spherical silica particle powder has a relative dielectric constant of 7.0 to 300 and a dielectric loss tangent of 0.02 or less at a frequency of 1 GHz, where M is a metal element selected from Groups 2, 3, 4, 12, 13, 14, and 15 of the periodic table:

2. The powder of spherical silica particles according to claim 1, wherein the median diameter of the powder of spherical silica particles is 0.5 to 20 μm.

3. The specific surface area of ​​the spherical silica particles is 0.1 to 5.0 m ２ The spherical silica particle powder according to claim 1, wherein the surface roughness is 1 / g.

4. The specific surface area A (m ２ / g) and the median diameter d50 (μm), the product A×d50 is 2.7 to 5.0 μm ２ The spherical silica particle powder according to claim 1, wherein the surface roughness is 1 / g.

5. The spherical silica particle powder according to claim 1, wherein the metal element M is a metal element of Periods 4 to 6 and Groups 2, 3, 4, 12, 14, and 15 of the periodic table.

6. A method for producing a powder of spherical silica particles according to any one of claims 1 to 5, comprising using a spherical silica precursor obtained by a wet method and causing the silica precursor to support at least one of the following metal elements M: M: a metal element selected from Groups 2, 3, 4, 12, 13, 14 and 15 of the periodic table.

7. The method for producing spherical silica particle powder according to claim 6, wherein the pore volume of the silica precursor is 0.1 to 2.0 g / cc.

8. The specific surface area of ​​the silica precursor is 100 to 1000 m ２ The method for producing a powder of spherical silica particles according to claim 6, wherein the average particle diameter is 1 / g.

9. A resin composition containing 5 to 90 mass % of the spherical silica particle powder according to any one of claims 1 to 5.

10. A slurry composition containing 1 to 80 mass % of the spherical silica particle powder according to any one of claims 1 to 5.

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