Silica powder, resin composition and dispersion

Abstract

The present invention provides a silica powder that, when used as a resin filler for semiconductor sealants or the like, can obtain a resin composition resin with excellent filling characteristics and narrow-gap penetration properties, allowing for the incorporation of a sufficient amount of filler. The silica powder of the present invention is characterized by having a cumulative 50% diameter D50 based on volume by laser diffraction scattering method of 0.05 to 2.00 μm, and an amount of independent particles exceeding 5 μm detected by dynamic image analysis method of less than 100 ppm.

Description

Technology Field

[0001] The present invention relates to silica powder, a resin composition, and a dispersion that can be suitably used as fillers for semiconductor sealants, liquid crystal sealants, films, etc. Background Technology

[0002] Recently, as electronic devices have become more high-performance, smaller, and lighter, the form of the semiconductor packages they are mounted on is also becoming more highly integrated, high-density, and thin. For the practical application of such semiconductor packages, the development of sealing materials suitable for the design is indispensable, along with the design of the integrated circuit.

[0003] For example, epoxy resin is mainly used as the underfill material filled between a semiconductor chip and a wiring board, but the epoxy resin, the semiconductor chip, and the wiring board each have different coefficients of linear expansion. Therefore, if the connection part cannot absorb stress, cracks may occur in the connection part. To suppress the occurrence of these cracks, fillers with a relatively small coefficient of linear expansion, such as silica, are dispersed in the underfill material. At this time, in order to suppress the coefficient of linear expansion of the sealant, it is required to increase the amount of low-expansion rate filler. In addition, sufficient narrow-gap penetration is required, that is, that no voids occur when the underfill material with added filler penetrates into the gap.

[0004] In order to increase the filling amount of the above filler, a hydrophilic dry silica powder with excellent dispersibility, a small diameter of dispersed particles, and a narrow particle size distribution during dispersion has been proposed (Patent Document 1). However, in the silica powder described in Patent Document 1, since the diameter of the dispersed particles is small, voids do not occur when infiltrated into the gap, but at the same time, it causes a thickening effect on the resin composition, and since the viscosity of the resin composition filled with it increases, a problem remains that a sufficient filling amount cannot be obtained.

[0005] In addition, a method has been proposed to improve affinity with the resin by treating the surface of silica particles with high particle size uniformity with a silane coupling agent (e.g., Patent Document 2). It was shown that when conventional silica particles described in Patent Document 2 are surface-treated with an epoxy group-containing silane coupling agent, the aggregation of silica particles alone during drying can be suppressed by further surface-treating the area where the silica particles aggregate alone with a nitrogen-containing compound, thereby suppressing the increase in viscosity when filling into the resin. Furthermore, it was shown that by suppressing aggregation, there is no need for classification. However, although the amount of aggregated particles can be reduced, the amount of coarse particles that do not pass through a sieve with a mesh size of 20 μm, defined as the amount of coarse particles, still remains at 0.1% or more, and when used as a filler for sealing materials, voids occur during penetration into gaps, which is a cause of molding defects. Prior art literature

[0006] Patent Document 1: Japanese Patent Publication No. 2014-152048 Patent Document 2: Japanese Patent Publication No. 2019-189509 The problem to be solved

[0007] Accordingly, the objective of the present invention is to provide a silica powder with excellent gap penetration. More specifically, the objective is to provide a silica powder that can obtain a resin composition resin with excellent filling characteristics and narrow gap penetration, which allows for the incorporation of a sufficient amount of filler. means of solving the problem

[0008] In order to solve the above problem, the inventors conducted a thorough investigation and discovered that even if the silica powder contains large-diameter particles (aggregated particles and independent particles), the silica powder having a specific particle size distribution and having reduced large-diameter independent particles exhibits excellent filling characteristics when kneaded with a resin and filled, as well as excellent narrow-gap penetration of the obtained resin composition, and also has good handling properties due to high fluidity in the powder state. Furthermore, in the present invention, independent particles refer to primary particles.

[0009] That is, the silica powder of the present invention is a silica powder comprising spherical silica particles, wherein the cumulative 50% diameter D50 based on volume, as determined by laser diffraction scattering of a dispersion solution dispersed by the following dispersion method A, is 0.05 to 2.00 μm and the cumulative 100% diameter D100 based on volume is 5 μm or less, and the amount of particles exceeding a particle diameter of 5 μm detected by dynamic image analysis of a dispersion solution dispersed by the following dispersion method B is 100 ppm or more and the amount of independent particles is less than 100 ppm.

[0010] [Dispersion Method A] A method of dispersing a 5 mass% ethanol suspension of silica powder for 5 minutes using an ultrasonic homogenizer at a frequency of 20 kHz.

[0011] [Dispersion Method B] A method of dispersing a 0.1 mass% aqueous suspension of silica powder using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes.

[0012] The silica powder of the present invention comprises spherical silica particles surface-treated with a silane coupling agent, wherein the component amount of the silane coupling agent is 2.0 to 22.0 particles / nm 2 It is desirable that it is.

[0013] In addition, it is preferable that the ratio (D100 / D50) of the volume-based cumulative 50% diameter D50 (μm) and the volume-based cumulative 100% diameter D100 (μm) obtained by the laser diffraction scattering method is 1 or more and 5 or less, and it is also preferable that the amount of coarse particles (V90) of the spherical silica particles obtained by Equation (1) from the volume-based cumulative 50% diameter D50 and the cumulative 90% diameter (D90) obtained by the laser diffraction scattering method is 10 or more and less than 100.

[0014] V90={(D90-D50) / D50}×100 (1) Effects of the invention

[0015] The silica powder of the present invention has good handling properties because it contains a specific amount of particles with a diameter exceeding 5 μm detected after dispersion by dispersion method B, and the cumulative diameter D50 based on volume measured after dispersion by dispersion method A is within a specific particle size range and the cumulative diameter D100 based on volume is less than a specific particle size, and the independent particles with a diameter exceeding 5 μm detected after dispersion by dispersion method B are reduced (the independent particles are less than a specific amount). Therefore, the resin composition to which the silica powder is added can achieve both excellent filling characteristics and narrow gap penetration. Accordingly, it is suitable as a filler for semiconductor sealants or semiconductor mounting adhesives. In particular, it can be suitably used as a filler for high-density mounting resins.

[0016] Silica powder contains independent particles and aggregated particles, and if the resin composition after adding and mixing silica powder contains a large number of independent particles or aggregated particles with large particle sizes (hereinafter also referred to as large particle sizes), when the resin composition is used as a filler for semiconductor sealing materials or semiconductor mounting adhesives, the penetration of the resin composition during gap penetration is inhibited by the large particles, and the narrow gap penetration performance is likely to be poor.

[0017] Although the silica powder of the present invention contains a specific amount of particles with a particle size exceeding 5 μm detected after dispersion by dispersion method B that imparts a weak shear, the resin composition using the silica powder of the present invention has excellent narrow-gap penetration because the cumulative 100% diameter D100 measured by volume after dispersion by dispersion method A that imparts a strong shear is less than the specific particle size, and the amount of independent particles with a particle size exceeding 5 μm detected after dispersion by the dispersion method B is less than the specific amount. This is presumed to be because the silica powder of the present invention contains aggregated particles and independent particles in a state where no shear is applied before being added to and kneaded with the resin, but in the resin composition after kneading with the resin and applying a shear, the aggregated particles are dispersed by the strong shear and become particles with a smaller particle size. Meanwhile, independent particles with a particle size exceeding 5 μm detected after dispersion by the above dispersion method B do not change in particle size due to strong shear, but in the silica powder of the present invention, the amount is reduced to less than a specific amount, so it does not affect narrow gap penetration. Specific details for implementing the invention

[0018] The silica powder of the present invention will be described in detail below based on embodiments.

[0019] [Silica Powder]

[0020] The silica powder of the present invention comprises spherical silica particles, and the cumulative 50% diameter D50 based on volume and the cumulative 100% diameter D100 based on volume, as determined by laser diffraction scattering of the dispersion solution dispersed by the following dispersion method A of the silica powder, is 0.05 to 2.00 μm and 5 μm or less.

[0021] [Dispersion Method A] A method of dispersing a 5 mass% ethanol suspension of silica powder for 5 minutes using an ultrasonic homogenizer at a frequency of 20 kHz.

[0022] Since dispersion method A applies strong shear using a low-frequency ultrasonic homogenizer, the measurement result obtained by the laser diffraction scattering method obtained by dispersion method A indicates the state of the silica powder during the mixing process when filling into the resin. By measuring the D100 of the silica powder dispersion solution by this dispersion method A, it can be shown that large particles are not detected in the particle size distribution and that particles can be dispersed by applying a large shear. However, since the detection level by the laser diffraction scattering method is only in the percent range and the detection sensitivity is low, it is not possible to detect or quantify trace amounts of particles exceeding D100 in the silica powder.

[0023] Here, the cumulative 50% diameter D50 based on volume is 0.05 to 2.00 μm. If it is less than 0.05 μm, it causes a thickening effect on the resin composition, and since the viscosity of the resin composition filled with it increases, there is a tendency not to obtain a sufficient amount of filling. If it exceeds 2.00 μm, when the resin composition filled with it penetrates the gap, penetration is inhibited because the gap narrowness and the difference in particle size are small, and voids tend to occur. If it is 0.05 to 2.00 μm, the viscosity of the resin composition can be maintained low even if a large amount of silica powder is filled into the resin.

[0024] In addition, the volume-based cumulative 100% diameter D100 of the dispersion solution dispersed by dispersion method A of silica powder is 5 μm or less. It is preferable that it be less than 3 μm.

[0025] Here, if the cumulative 100% diameter D100 by volume exceeds 5 μm, the existing particles hinder gap penetration, causing voids and resulting in molding defects. If D100 is 5 μm or less and the amount of independent particles exceeding 5 μm by the method described below is less than 100 ppm, good narrow-gap penetration can be achieved when the resin composition penetrates the gaps even if a large amount of silica powder is added to the resin. It is preferable that the cumulative 100% diameter D100 by volume is 3 μm or less.

[0026] In addition, the silica powder of the present invention has a particle size exceeding 5 μm detected by dynamic image analysis of a dispersion dispersed by the following dispersion method B, which is 100 ppm or more, and an independent particle size exceeding 5 μm is less than 100 ppm.

[0027] [Dispersion Method B] A method of dispersing a 0.1 mass% aqueous suspension of silica powder using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes.

[0028] As described above, in addition to using the laser diffraction scattering method to measure the particle size distribution of a dispersion solution dispersed by dispersion method A, which imparts strong shear, the amount of particles exceeding 5 μm and the amount of independent particles exceeding 5 μm were measured for a dispersion solution dispersed by dispersion method B using dynamic image analysis. Since dispersion method B imparts weak shear using a high-frequency ultrasonic cleaner, the particles exceeding 5 μm detected by dynamic image analysis include aggregated particles that are dispersed by strong shear and become particles of smaller diameter, and independent particles that are not dispersed even by strong shear. Independent particles exceeding 5 μm are particles that are not dispersed even by strong shear. Furthermore, in order to identify and detect the aggregated particles and independent particles, the image is filtered using parameters representing the shape. In the "circularity" calculated by dynamic image analysis, particles with a circularity of 0.90 or higher are judged to have high circularity and are independent spherical particles, while particles with a circularity of less than 0.90 are judged to be irregular and are identified as aggregated particles likely formed by the aggregation of primary particles.

[0029] The amount of particles exceeding 5 μm detected by the dynamic image analysis method of silica powder is 100 ppm or more. As described above, the particles detected here include both aggregated particles formed by the aggregation of primary particles and independent particles. If this amount of particles is 100 ppm or more, the fluidity of the silica powder can be increased, thereby improving the handling properties when adding silica powder to a resin.

[0030] Meanwhile, the amount of independent particles exceeding 5 μm is less than 100 ppm. Less than 50 ppm is preferable, and less than 10 ppm is more preferable. If the amount of independent particles exceeding 5 μm is 100 ppm or more, the existing independent particles do not penetrate into the gaps, and there is a risk that voids will be generated, causing molding defects. If it is less than 100 ppm, good narrow-gap penetration can be exhibited when the resin composition penetrates into the gaps, even if a large amount of spherical silica particles is added to the resin.

[0031] That is, if the amount of particles exceeding 5 μm detected by the dynamic image analysis method of the dispersion solution dispersed by dispersion method B is 100 ppm or more and the amount of independent particles exceeding 5 μm is less than 100 ppm, then the silica powder of the present invention before applying shear has high fluidity because there are 100 ppm or more of aggregated particles exceeding 5 μm and independent particles exceeding 5 μm, and thus the handling properties when adding silica powder to the resin are good. After applying strong shear and dispersing the silica powder in the resin, the aggregated particles exceeding 5 μm are dispersed by the strong shear, and the independent particles exceeding 5 μm are less than 100 ppm, so even if a large amount of spherical silica particles are added to the resin, good narrow-gap penetration properties are exhibited when penetrating the resin composition into the gaps. In addition, if the amount of particles exceeding 3 μm detected by the dynamic image analysis method of the dispersion solution dispersed by dispersion method B is 100 ppm or more and the amount of independent particles exceeding 3 μm is less than 100 ppm, then the silica powder of the present invention before applying shear has 100 ppm or more of aggregated particles exceeding 3 μm and independent particles exceeding 3 μm, so the fluidity is high and the handling properties are good when adding silica powder to the resin. After applying strong shear and dispersing the silica powder in the resin, the aggregated particles exceeding 3 μm are dispersed by the strong shear, and the independent particles exceeding 3 μm are less than 100 ppm, so even if a large amount of spherical silica particles are added to the resin, the time required for gap penetration can be shortened when penetrating the resin composition into the gap, and good narrow gap penetration properties are exhibited.

[0032] In addition, it is preferable that the sphericity of particles 5 μm or smaller detected by the dynamic image analysis method of silica powder be 0.90 or higher. If the sphericity is 0.90 or higher, the proportion of spherical particles increases, and since fluidity increases, good narrow-gap penetration can be achieved.

[0033] It is preferable that the aspect ratio of particles 5 μm or smaller detected by the dynamic image analysis method of silica powder be 0.92 or higher. If the aspect ratio is 0.92 or higher, the proportion of spherical particles increases, and since fluidity increases, good narrow-gap penetration can be exhibited.

[0034] In the present invention, the spherical silica particles may be surface-treated with a silane coupling agent. The component amount of the silane coupling agent is 2.0 to 22.0 particles / nm. 2 It is desirable that it be 4.0 to 18.0 pieces / nm 2 ...is more preferable. The component amount of the silane coupling agent is 2.0 to 22.0 atoms / nm. 2 On this side, reactive hydroxyl groups on the surface of silica particles can be sufficiently blocked from the resin. 2.0 groups / nm 2 If this is the case, reactive hydroxyl groups on the surface of silica particles are blocked from the organic resin, and affinity tends to improve, and also 22.0 groups / nm 2 If the amount is less than or equal to the amount of excess silane coupling agent, the dispersibility of the silica particles tends to improve.

[0035] The particle size distribution of silica powder can be expressed as the ratio (D100 / D50) when the cumulative volume-based particle size distribution obtained by laser diffraction scattering is 50 volume% diameter D50 and the maximum particle diameter is D100. It is preferable that (D100 / D50) is 1 or more and 5 or less. If (D100 / D50) is 1 or more and 5 or less, spherical silica particles tend to be packed in the resin in a form close to close packing, and even if a large amount of spherical silica particles are packed, the amount of resin not contained in the interparticle gaps increases, so the viscosity of the resin composition can be maintained low.

[0036] In addition, the amount of coarse particles of silica powder can be expressed as V90, which is calculated by the following equation (1).

[0037] V90={(D90-D50) / D50}×100 (1)

[0038] D50: Cumulative 50 volume% diameter of the volume-based particle size distribution obtained by laser diffraction scattering.

[0039] D90: Cumulative 90% volumetric diameter of the volumetric particle size distribution obtained by laser diffraction scattering.

[0040] It is preferable that V90 be 10 or more and less than 100, more preferable that it be 10 to 95, and even more preferable that it be 20 to 90. If V90 is 10 or more and less than 100, good gap penetration can be obtained when the resin composition is infiltrated into the gap.

[0041] [use]

[0042] The uses of the silica powder of the present invention are not particularly limited. For example, it can be used as a filler for semiconductor sealants or semiconductor mounting adhesives, as a filler for die attach films or die attach pastes, or as a filler for resin compositions such as insulating films of semiconductor package substrates. In particular, the spherical silica particles obtained in the present invention can be suitably used as a filler for high-density mounting resin compositions.

[0043] In addition, the silica powder of the present invention can also be used as abrasive particles for Chemical Mechanical Polishing (CMP) abrasives, abrasive particles for grinding wheels used for grinding, toner additives, additives for liquid crystal seals, dental fillers, or inkjet coating agents.

[0044] [Method for manufacturing silica powder]

[0045] Next, the method for manufacturing silica powder of the present invention will be described.

[0046] Silica-based spherical particles are classified to obtain silica powder containing spherical silica particles. This is explained in detail below.

[0047] Silica-based spherical particles

[0048] The silica-based spherical particles used in the present invention are preferably silica-based spherical particles having an average particle diameter of 0.05 to 2.00 μm as determined by laser diffraction scattering.

[0049] In addition, as silica-based spherical particles, a wet silica-based spherical particle dispersion obtained by the sol-gel method may be used. Here, the sol-gel method involves hydrolyzing and polycondensing silicon alkoxide in a reaction medium containing water and an organic solvent containing a catalyst to produce a silica sol, and then gelling the silica sol to obtain a wet silica-based spherical particle dispersion.

[0050] In addition, as silica-based spherical particles, dry silica-based spherical particles obtained by the flame method may be used. Here, the flame method is produced by burning a silicon compound, and the dry silica-based spherical particles can be obtained by growing and aggregating in and near the flame. For example, International Publication No. 2020 / 175160 describes a method for manufacturing silica by burning a silicon compound, wherein a burner having a concentric multi-tube structure of three or more tubes is installed in a reactor having a jacket section for cooling around it, and by adjusting the combustion conditions of the flame and the cooling conditions, a silica powder can be obtained in which the cumulative 50% mass diameter of the mass-based particle size distribution obtained by centrifugal sedimentation is 300 nm or more and 500 nm or less.

[0051] Classification Processing

[0052] Spherical silica particles with reduced independent particles can be obtained by classifying silica-based spherical particles. For example, the above wet silica-based spherical particle dispersion is wet-filtered to remove the contained independent particles. That is, by filtering the above wet silica-based spherical particle dispersion, if independent particles, as well as bonded particles or aggregated clumps, are generated on the filter material along with reaction residues, etc., these are also separated. Here, as for the filter material, a wet filtration filter with a mesh size of 5 μm or less can be used without special limitation, and suitably, a filter with a mesh size of 3 μm or less may also be used. If the mesh size becomes excessively small, not only is filtration performance reduced, but the average particle size of the silica particles being filtered also varies greatly from the above range; therefore, although it varies depending on the average particle diameter of the target powder, the lower limit of the mesh size is typically 1 μm. The material of the filter is not particularly limited, but examples include resin materials (polypropylene, PTFE, etc.) or metal materials. From the perspective of preventing the incorporation of metal impurities, it is desirable to use a resin filter.

[0053] In addition, since the dry silica-based spherical particles are powders by manufacturing method, they may be dispersed in a solvent and filtered wet. The solvent used is not particularly limited, but it is preferable to select a solvent that allows the dry silica-based particles to be easily dispersed.

[0054] In addition, classification treatment utilizing inertial force, such as a liquid cyclone or wind classification, may be used. The medium used is not particularly limited, but it is preferable to use liquid for wet silica-based spherical particles and air for dry silica-based spherical particles, as this ensures good dispersibility in the medium.

[0055] Separation Processing

[0056] In this embodiment, the spherical silica particles obtained by classification may be recovered as a cake by solid-liquid separation as needed. Alternatively, solid-liquid separation may be performed after forming weak aggregates by adding a flocculating agent. By adding a flocculating agent, the solid and liquid can be separated and easily recovered. The filtration method is not particularly limited, and known methods such as vacuum filtration, pressurized filtration, and centrifugal filtration may be applied.

[0057] In addition, the added coagulant is not particularly limited, but from the perspective of the concern regarding incorporation into the obtained spherical silica particles, a coagulant comprising a compound that does not contain metal element components such as carbon dioxide, ammonium carbonate, ammonium bicarbonate, and ammonium carbamate is suitable.

[0058] <Drying Treatment>

[0059] In this embodiment, the cake containing spherical silica particles obtained by separation treatment can be dried as needed to obtain silica powder containing spherical silica particles.

[0060] The drying method is not particularly limited, and known methods such as air drying or vacuum drying may be adopted. However, since drying under reduced pressure tends to result in easier disintegration than drying under atmospheric pressure, it is preferable to adopt vacuum drying.

[0061] In addition, the drying temperature is preferably 35 to 200°C, more preferably 50 to 200°C, particularly preferably 80 to 200°C, and especially preferably 120 to 200°C. If the drying temperature is 35 to 200°C, it is advantageous from the perspective of making the silica powder easy to disintegrate.

[0062] <Sintering>

[0063] In this embodiment, the silica powder containing spherical silica particles obtained by drying treatment can be calcined as needed.

[0064] Silica powder containing spherical silica particles after drying has residual silanol groups because the dispersion medium absorbed within the particles has not been completely removed; in particular, spherical silica particles made using wet silica-based spherical particles contain pores. In order to highly remove the dispersion medium within the particles and break down the silanol groups to obtain solid silica, it is desirable to perform a calcination treatment depending on the application. That is, silica particles treated in the above calcination process are desirable not only because the amount of silanol groups on the particle surface is reduced, but also because the dispersion medium remaining within the particles is removed. When the solvent remaining within the particles is used as a resin filler, heating causes bubbles and other issues, which lead to a decrease in yield. This is particularly pronounced in applications requiring high filling rates, such as semiconductor sealants or liquid crystal sealants. Therefore, it is desirable to implement the above process, especially when manufacturing silica particles used for semiconductor sealants or liquid crystal sealants.

[0065] The calcination temperature during the above calcination treatment is preferably 300 to 1300°C, or furthermore 600 to 1200°C, because if it is too low, it is difficult to remove the dispersion medium components, and if it is too high, fusion of the silica particles occurs. The calcination time is not particularly limited as long as the remaining dispersion medium is removed, but since productivity decreases if it is too long, it is sufficient to raise the temperature to the target calcination temperature and then maintain the temperature in the range of 0.5 to 48 hours, more preferably 2 to 24 hours, to perform calcination. The atmosphere during calcination is also not particularly limited and can be performed under an inert gas such as argon or nitrogen, or under an atmospheric atmosphere.

[0066] The silica powder of the present invention may also be used after undergoing a disintegration treatment by a known disintegration means to further reduce agglomerated lumps, if necessary. The disintegration method is not particularly limited, and known methods such as a ball mill or a jet mill may be employed.

[0067] [Surface treatment with silane coupling agent]

[0068] Spherical silica particles may be surface-treated with a silane coupling agent. This will be explained in detail below.

[0069] Silane coupling agents

[0070] Examples of silane coupling agents include those represented by the following formula (2).

[0071] R n -Si-X (4-n) (2)

[0072] However, in the above formula (2), R is an organic group having 1 to 18 carbon atoms, X is a hydrolyzable group, and n is an integer from 1 to 3.

[0073] In addition, the above X may include alkoxy groups having 1 to 3 carbon atoms, such as methoxy groups, ethoxy groups, and propoxy groups, and / or halogen atoms such as chlorine atoms, among which methoxy groups and / or ethoxy groups are preferred. In addition, when n is 1 or 2, the plurality of Xs may be the same or different, but are preferred to be the same. In addition, n is an integer from 1 to 3, but is preferred to be 1 or 2, and is particularly preferred to be 1.

[0074] As silane coupling agents that can be given by the above formula (2), methyltrimethoxysilane, methyltrimethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxytrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, Examples include N,N-dimethyl-3-aminopropyltrimethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane, 4-styryltrimethoxysilane, etc.

[0075] Surface treatment agents (other additives)

[0076] In addition, in addition to the silane coupling agent, at least one surface treatment agent selected from silicone oil, siloxanes, and / or silane residues may be added. The surface treatment agent may be added simultaneously with the silane coupling agent, or the silane coupling agent may be added after the surface treatment agent. Furthermore, the surface treatment agent may be added after the silane coupling agent. By doing so, spherical silica particles with various surface properties are obtained. For example, spherical silica particles composed of trimethylsilyl groups and epoxy groups can be easily obtained.

[0077] The amount of surface treatment agent used is preferably 0.05 to 80 parts by mass per 1 part by weight of spherical silica particles in the case of silicone oil, more preferably 0.1 to 60 parts by mass, and most preferably 1 to 20 parts by mass. Likewise, in the case of siloxanes, it is preferably 0.001 to 40 parts by mass per 1 part by weight of spherical silica particles, more preferably 0.003 to 30 parts by mass, and most preferably 0.005 to 20 parts by mass. Likewise, in the case of silazanes, it is preferably 0.001 to 40 parts by mass per 1 part by weight of silica powder, more preferably 0.003 to 30 parts by mass, and most preferably 0.005 to 20 parts by mass.

[0078] Mixed

[0079] Spherical silica particles and a silane coupling agent are mixed using a conventionally known method. For example, spherical silica particles are placed in a mixing container, and a predetermined amount of silane coupling agent is added by dropping or spraying while the spherical silica particles are fluidized by shaking or stirring. For example, silica powder is added into the container, and stirring is initiated by rotating a stirring blade. Then, the silane coupling agent is added using a peristaltic pump. The addition rate can be appropriately adjusted according to the amount added.

[0080] After adding the silane coupling agent, it is preferable to continue stirring for at least 10 minutes. By continuing the stirring, the silane coupling agent can be uniformly attached to the surface of the spherical silica particles.

[0081] Examples of mixing vessels include Henschel-type mixing devices equipped with stirring blades or mixing blades, Redige mixers, air blenders that mix airflow using air, V blenders that mix by the rotation or oscillation of the vessel body, double cone-type mixing devices, and locking mixers.

[0082] <Heat Treatment>

[0083] By performing a heat treatment, some of the added silane coupling agents react with the surface of the silica particles (i.e., chemical bonding), while the remaining silane coupling agents do not chemically bond and remain on the surface of the silica particles (i.e., physical adsorption). If the temperature at which the heat treatment is performed is too low, the reaction proceeds slowly, which reduces production efficiency; if it is too high, it promotes the decomposition of the silane coupling agent or surface treatment agent, or the formation of aggregation due to rapid polymerization reactions. Therefore, although it varies depending on the silane coupling agent used, it is generally preferable to perform the treatment at 25 to 300°C, preferably 40 to 250°C.

[0084] The heat treatment time can be appropriately determined based on the reactivity of the silane coupling agent used. Typically, it is possible to obtain a sufficient reaction rate within 1 hour or more and 500 hours.

[0085] In addition, if heat treatment is possible within the mixing container used for mixing, the mixed powder may be provided directly to the heat treatment within the device.

[0086] <Drying Treatment>

[0087] The drying temperature is not particularly limited, but if the temperature is high, the silane coupling agent component (physical adsorption) existing without chemical bonding volatilizes and is removed from the spherical silica particles, which is undesirable, and if the temperature is low, the by-product cannot be sufficiently removed. Therefore, it is preferable to set the drying temperature to 25 to 200°C, more preferable to set it to 25 to 180°C, and even more preferable to set it to 25 to 150°C. By drying at 25°C or higher, the by-product generated when the silane coupling agent reacts with the surface of the silica particles can be sufficiently removed.

[0088] The device used for drying is not particularly limited, and conventionally known drying devices may be used. Additionally, if drying is possible within the reaction vessel used for heat treatment, the treated powder may be provided directly to the drying treatment within the device.

[0089] It is preferable that the pressure inside the device during drying be at or above atmospheric pressure. Specifically, it is preferable that it be at or above 1000 hPa. By drying at a pressure at or above atmospheric pressure, unreacted silane coupling agents can be sufficiently removed. If the pressure is at or above 1000 hPa, by-products can be sufficiently removed without volatilizing physically adsorbed silane coupling agent components.

[0090] The drying time is not specifically limited and can be appropriately selected according to drying conditions, such as drying temperature or pressure, but generally, by drying for about 1 to 48 hours, surface-treated silica powder with by-products removed can be obtained.

[0091] [Dispersion]

[0092] The silica powder of the present invention can be dispersed in a solvent to form a dispersed body. The solvent used to disperse the silica powder is not particularly limited as long as it is a solvent that facilitates the dispersion of the silica powder.

[0093] As such solvents, organic solvents such as water, alcohols, ethers, and ketones may be used. Examples of the above alcohols include methanol, ethanol, and 2-propyl alcohol. As a solvent, a mixture of water and one or more of the above organic solvents may be used. In addition, to improve the stability and dispersibility of the silica powder, various additives such as dispersants like surfactants, thickeners, wetting agents, defoaming agents, or acidic or alkaline pH adjusters may be added. Furthermore, the pH of the dispersion is not limited.

[0094] Applications of the dispersion include filling into semiconductor sealants or semiconductor mounting adhesives. If the dispersion is silica powder that has been pre-dispersed in a solvent, it is easily dispersed in the resin. For example, by mixing the resin and the dispersion and then removing the solvent, an underfill material in which the filler is well dispersed can be easily prepared.

[0095] [Resin Composition]

[0096] The type of resin to which silica powder is blended to prepare the resin composition of the present invention is not particularly limited. The type of resin may be appropriately selected according to the desired application, and examples include epoxy resin, acrylic resin, silicone resin, olefin-based resin, polyimide resin and / or polyester-based resin.

[0097] A method for preparing a resin composition may be appropriately adopted from known methods, and silica powder, various resins, and other components blended as needed may be mixed.

[0098] When the dispersion of the present invention is mixed into a resin, a resin composition with a better dispersion of silica powder in the resin can be obtained compared to when dry silica powder is mixed into the resin. A good dispersion of silica powder means that there are fewer aggregated particles in the resin composition. Therefore, the performance of both viscosity characteristics and interstitial penetration of a resin composition containing the silica powder of the present invention as a filler can be further improved.

[0099] Applications of the resin composition include semiconductor sealants and semiconductor mounting adhesives. A resin composition incorporating silica powder is suitable for the above applications because it can suppress the coefficient of linear expansion.

[0100] [organize]

[0101] As understood from the above description, the silica powder according to the first embodiment of the present invention is a silica powder comprising spherical silica particles, characterized in that the cumulative 50% diameter D50 based on volume by laser diffraction scattering of the dispersion solution dispersed by the following dispersion method A is 0.05 to 2.00 μm, and the cumulative 100% diameter D100 based on volume is 5 μm or less, and the amount of particles exceeding 5 μm detected by dynamic image analysis of the dispersion solution dispersed by the following dispersion method B is 100 ppm or more, and the amount of independent particles exceeding 5 μm is less than 100 ppm.

[0102] [Dispersion Method A] A method of dispersing a 5 mass% ethanol suspension of silica powder for 5 minutes using an ultrasonic homogenizer at a frequency of 20 kHz.

[0103] [Dispersion Method B] A method of dispersing a 0.1 mass% aqueous suspension of silica powder using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes.

[0104] With such silica powder, when added to a resin, a high filling amount is obtained, and excellent filling characteristics and narrow gap penetration can be achieved without hindering the penetration of the resin composition during gap penetration.

[0105] The silica powder according to the second aspect of the present invention is, in the silica powder according to the first aspect described above, wherein spherical silica particles are surface-treated with a silane coupling agent, and the component amount of the silane coupling agent is 2.0 to 22.0 particles / nm 2 It is characterized by being.

[0106] The silica powder according to the third embodiment of the present invention is characterized in that, in the silica powder according to the first or second embodiment described above, the ratio (D100 / D50) of the volume-based cumulative 50% diameter D50 (μm) and the volume-based cumulative 100% diameter D100 (μm) obtained by laser diffraction scattering is 1 or more and 5 or less.

[0107] The silica powder according to the fourth embodiment of the present invention is characterized in that, in the silica powder according to the first or second embodiment described above, the amount of coarse particles (V90) of the silica powder obtained by Equation (1) from the volume-based cumulative 50% diameter D50 and cumulative 90% diameter D90 obtained by laser diffraction scattering method is 10 or more and less than 100.

[0108] V90={(D90-D50) / D50}×100 (1)

[0109] A resin composition according to the fifth embodiment of the present invention is formed by dispersing silica powder according to the first or second embodiment described above in a resin.

[0110] A dispersion according to the sixth aspect of the present invention is formed by dispersing silica powder according to the first or second aspect described above in a solvent.

[0111] Examples

[0112] The following describes specific examples of the present embodiment, but the present invention is not limited in any way by these examples.

[0113] The measurement and evaluation methods for each physical property of silica powder are as follows.

[0114] (Volume-based particle size distribution by laser diffraction scattering)

[0115] About 0.5 g of silica powder was weighed into a 50 mL glass bottle using an electronic balance, 10 g of ethanol was added, and the mixture was dispersed using an ultrasonic homogenizer (Sonifier 250 manufactured by Branson) under conditions of a frequency of 20 kHz and 5 minutes. Then, the volume-based cumulative diameter D50 (㎛), volume-based cumulative diameter D100 (㎛), and volume-based cumulative diameter D90 (㎛) of spherical silica particles were measured using a laser diffraction scattering particle size distribution measuring device (LS13 320 manufactured by Beckmann Coulter). From the obtained D50 and D90, the amount of coarse particles (V90) of the surface-treated silica powder was calculated using Equation (1).

[0116] V90={(D90-D50) / D50}×100 (1)

[0117] (Dynamic Image Analysis Method)

[0118] (Method for measuring circularity, aspect ratio, particle size exceeding 5 μm, and independent particle size exceeding 5 μm by dynamic image analysis)

[0119] (1) For dynamic image analysis, a dispersion of silica powder dispersed in pure water was used. The dispersion was prepared by adding 0.03 g of silica powder and 0.1 mL of 0.1 M sodium hydroxide solution to 30 g of ultrapure water to prepare a 0.1 mass% suspension, and then dispersing it for 30 minutes using an ultrasonic cleaner at a frequency of 40 kHz.

[0120] (2) The dispersion obtained in (1) was measured using a dynamic image analysis device [Parshe Analyzer manufactured by Hosokawa Micron] to obtain the particle image in 0.015 mL of the dispersion. For the obtained particle image, "circle equivalent diameter d", "circularity" and "aspect ratio" were obtained through internal calculations of the device.

[0121] (3) When calculating the amount of particles exceeding 5 μm and the amount of independent particles exceeding 5 μm from the particle image obtained in (2), only particles with “circle equivalent diameter d > 5 μm” were selected, and the number of particles exceeding 5 μm was counted. Additionally, the particles exceeding 5 μm were identified as “circularity ≥ 0.9” and “aspect ratio ≥ 0.92”, and the number of independent particles exceeding 5 μm was counted. Here, using the particle's circle equivalent diameter d [μm], the amount of particles exceeding 5 μm and the amount of independent particles exceeding 5 μm, respectively, W [ppm] was calculated using the calculation method of (4) below. When calculating the amount of particles exceeding 3 μm and the amount of independent particles exceeding 3 μm, the calculation was performed in the same manner except that only particles with “circle equivalent diameter d > 3 μm” were selected from the particle image obtained in (2).

[0122] (4) The mass w [g] per particle was calculated from Equation (i) using the circle equivalent diameter d [㎛] obtained from dynamic image analysis. ρ is the true density of amorphous silica ρ = 2.2 [g·m -3 The value of ] was used.

[0123] w=ρ×π / 6×(d÷10 6 ) 3 (i)

[0124] This operation was performed for each particle detected by dynamic image analysis to calculate the weight of each particle. The sum of all these was taken as the total weight ws [g], and from Equation (ii), the particle weight W [ppm] at the amount of spherical silica particles provided for measurement was obtained.

[0125] W=ws / (0.015×(0.1 / 100) (ii)

[0126] In addition, the lower detection limit in this measurement method was calculated by measuring 0.015 mL of a dispersion to which a known amount of standard particle 1 (Thermo Fisher Scientific 4206A) was added to the dispersion obtained in (1) above. The amount of independent particles obtained by measuring the dispersion to which the standard particles were added represents the amount of standard particles detected, and from this result, the lower detection limit for particle amounts exceeding 5 μm was stated to be 10 ppm. In the same way, a dispersion to which standard particle 2 (Thermo Fisher Scientific 4204A) was added was measured, and the lower detection limit for particle amounts exceeding 3 μm was stated to be 10 ppm.

[0127] (Method for measuring the amount of silane coupling agent component in silica powder)

[0128] Using the carbon content of the silica powder (described later), the BET specific surface area of ​​the silica powder (described later), and the number of carbon atoms of the silane coupling agent (unitless), the amount of the silane coupling agent component (amounts / nm) 2 ) was calculated using the following formula.

[0129] Silane coupling agent component amount (units / nm) 2 ) = Carbon content of spherical silica particles (mass%) / 100 / 12 (atomic weight of carbon) / {Number of carbon atoms in silane coupling agent - N} × Avogadro's number (atoms / mol) / BET specific surface area of ​​silica powder (m² / g) / 10 18

[0130] (In the formula, the number of carbon atoms in the silane coupling agent is the number of carbon atoms in the molecular formula of the silane coupling agent used. For example, if KBM-403 manufactured by Shin-Etsu Silicon is used, the silane coupling agent has the molecular formula C9H 20 Because it has O5Si, the number of carbon atoms in the silane coupling agent is 9. N is the number of carbon atoms of the hydrolysis group X of the silane coupling agent × 2. For example, if X is a methoxy group, N is 2, and if X is an ethoxy group, N is 4. Avogadro's number is 6.02 × 10⁻⁶. 23It is (a mole).

[0131] (Carbon content)

[0132] The carbon content (mass%) was measured using a total nitrogen total carbon measuring device (Sumigraph NC-TR22 manufactured by Sumika Bunseki Center). In addition, the silica sample for measurement was set to 50–100 mg.

[0133] (BET specific surface area)

[0134] The BET specific surface area S (m² / g) was measured by the nitrogen adsorption BET 1-point method using a specific surface area measuring device (SA-1000 manufactured by Shibata Rikagaku).

[0135] (Evaluation of Silica Powder's Interstitial Penetration)

[0136] 36 g of silica powder was added to a mixture of 17 g of bisphenol F-type epoxy resin (YDF-8170C manufactured by Nittetsu Chemical & Material) and 7 g of amine curing agent (KARAHARD AA manufactured by Nippon Kayaku), and kneaded by hand. The resin composition kneaded by hand was pre-kneaded using a rotary mixer (Awatori Rentaro AR-500 manufactured by THINKY) (kneading: 1000 rpm, 8 minutes; degassing: 2000 rpm, 2 minutes). After pre-kneading, the resin composition was stored in a constant temperature water bath at 25°C, and then kneaded using a 3-roller (BR-150HCV manufactured by IMEX, roll diameter φ63.5). The kneading conditions were set as follows: kneading temperature at 25°C, distance between rolls at 20 μm, and kneading frequency at 8 times. The obtained resin composition was degassed for 30 minutes under reduced pressure using a vacuum pump (TSW-150 manufactured by Sato Shinku) to obtain a blended resin composition. This blended resin composition was poured into the opening of a gap heated to 110°C by stacking two sheets of glass with a gap of 30 μm, and a high-temperature penetration test was performed. The presence or absence of flow marks was evaluated by visual inspection. If no flow marks were visible, the gap penetration was judged to be good, and if flow marks were visible, the gap penetration was judged to be poor. Here, if the gap penetration is good, it is considered that the silica powder has excellent packing and viscosity characteristics.

[0137] [Example 1-1]

[0138] As a reaction medium, 4.3 parts by mass of methanol, 1.7 parts by mass of isopropanol, and 1.4 parts by mass of ammonia water (25 mass%) were prepared, and the reaction temperature was set to 40°C and stirred. Then, a mixture of 0.2 parts by mass of tetramethoxysilane, 0.4 parts by mass of methanol, and 0.1 parts by mass of isopropanol was added to the reaction medium as a raw material to produce silica seed particles. Next, 100 parts by mass of tetramethoxysilane and 28.5 parts by mass of methanol were supplied into the reaction medium, and simultaneously 42.8 parts by mass of ammonia water (25 mass%) was supplied to grow and synthesize sol-gel silica particles. After the supply was finished, stirring was continued for 1 hour to obtain a silica-based spherical particle dispersion with an average particle diameter of 1.0 μm. The silica-based spherical particle dispersion was wet-filtered using a polypropylene filter with a mesh size of 3 μm to remove isolated particles. Subsequently, 0.9 parts by mass of dry ice were added, and the mixture was left for 20 hours. After 20 hours, the sol-gel silica particles had settled, and a cake was obtained by separating the solid and liquid using a quantitative filter paper (grain particle size 6 μm). Additionally, vacuum drying was performed at 100°C for 15 hours. Subsequently, calcination was performed at 800°C for 10 hours under an air atmosphere. Furthermore, a disintegration treatment was carried out using a jet mill to obtain silica powder 1. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0139] [Examples 1-2]

[0140] Silica powder 2 was prepared and measured in the same manner as in Example 1-1, except that the mesh size of the polypropylene filter used for wet filtration was changed from 3 μm to 5 μm. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0141] [Examples 1-3]

[0142] In Example 1-1, the reaction medium was changed to 21.4 parts by mass of methanol, 8.6 parts by mass of isopropanol, and 7.1 parts by mass of ammonia water (25 mass%). Subsequently, the raw materials for preparing silica seed particles were changed to 0.9 parts by mass of tetraethoxysilane, 2.0 parts by mass of methanol, and 0.6 parts by mass of isopropanol to prepare silica seed particles. Afterward, silica powder 3 was prepared and measured in the same manner as in Example 1-1. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0143] [Examples 1-4]

[0144] In Example 1-1, the reaction medium was changed to 83.3 parts by weight of methanol, 33.3 parts by weight of isopropanol, and 27.8 parts by weight of water ammonia (25 mass%). Subsequently, the raw materials for preparing silica seed particles were changed to 3.3 parts by weight of tetraethoxysilane, 7.8 parts by weight of methanol, and 2.2 parts by weight of isopropanol to prepare silica seed particles. Next, the raw materials after preparing the silica seed particles were changed to 100 parts by weight of tetramethoxysilane, 27.8 parts by weight of methanol, and 44.4 parts by weight of water ammonia (25 mass%). Afterward, silica powder 4 was prepared and measured in the same manner as in Example 1-1. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0145] [Examples 1-5]

[0146] In Example 1-1, the reaction medium was changed to 50.0 parts by mass of methanol and 8.3 parts by mass of ammonia water (25 mass%). Subsequently, a mixture of 100 parts by mass of tetramethoxysilane, 10.0 parts by mass of methanol, and 46.7 parts by mass of ammonia water (25 mass%) was added to the reaction medium as a raw material to grow and synthesize sol-gel silica particles. Afterward, silica powder 5 was prepared and measured in the same manner as in Example 1-1. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0147] [Examples 1-6]

[0148] In Example 1-1, the reaction medium was changed to 1.8 parts by mass of methanol, 0.7 parts by mass of isopropanol, and 0.6 parts by mass of ammonia water (25 mass%). Subsequently, the raw materials for preparing silica seed particles were changed to 0.1 parts by mass of tetraethoxysilane, 0.2 parts by mass of methanol, and 0.1 parts by mass of isopropanol to prepare silica seed particles. Afterward, silica powder 6 was prepared and measured in the same manner as in Example 1-1. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0149] [Examples 1-7]

[0150] Silica powder 7 was prepared and measured in the same manner as in Examples 1-6, except that the mesh size of the polypropylene filter used for wet filtration was changed from 3 μm to 5 μm. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0151] [Examples 1-8]

[0152] 5 parts by mass of dry silica-based spherical particles (silfil NSS-40D manufactured by Tokuyama Corporation) with an average particle diameter of 0.38 μm were added to 100 parts by mass of pure water to prepare a dry silica-based spherical particle dispersion. This dry silica-based spherical particle dispersion was wet-filtered using a polypropylene filter with a mesh size of 3 μm to remove isolated particles, thereby preparing silica particles 8, which were then measured. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0153] [Examples 1-9]

[0154] Silica powder 9 was prepared and measured in the same manner as in Examples 1-8, except that dry silica-based spherical particles with an average particle diameter of 0.24 μm (Silfil NSS-24D manufactured by Tokuyama Corporation) were used instead of dry silica-based spherical particles with an average particle diameter of 0.38 μm (Silfil NSS-40D manufactured by Tokuyama Corporation). Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0155] [Examples 1-10]

[0156] Silica powder 10 was prepared by classifying dry silica-based spherical particles (Silphil NSS-40D manufactured by Tokuyama Corporation) with an average particle diameter of 0.38 μm using a wind classifier, and was measured. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0157] [Comparative Example 1-1]

[0158] Silica powder A was prepared and measured in the same manner as in Example 1-1, except that wet filtration using a polypropylene filter with a mesh size of 3 μm was not performed. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0159] [Comparative Example 1-2]

[0160] Silica powder B was prepared and measured in the same manner as in Example 1-1, except that the polypropylene filter used for wet filtration was changed from a mesh size of 3 μm to 7 μm. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0161] [Comparative Example 1-3]

[0162] Silica powder C was prepared and measured in the same manner as in Example 1-1, except that the mesh size of the polypropylene filter used for wet filtration was changed from 3 μm to 10 μm. Table 1 shows the characteristics and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0163] [Comparative Example 1-4]

[0164] Commercially available spherical silica powder D was measured. Table 1 shows the characteristics of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0165] [Comparative Example 1-5]

[0166] Commercially available spherical silica powder E was measured. Table 1 shows the characteristics of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0167]

[0168]

[0169] [Example 2-1]

[0170] Silica powder 1 prepared in Example 1-1 was placed into a mixing vessel and stirring was initiated. Subsequently, 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon Co., Ltd.) and 0.5 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were supplied to 100 parts by mass of silica powder 1 as a surface treatment agent using a peristaltic pump (SJ-1211 II-H manufactured by ATTA). After supplying, stirring was continued and mixed for 15 minutes. After mixing, stirring was continued, and the temperature was raised from room temperature to 40°C over 20 minutes, and then maintained at 40°C for 60 minutes. Subsequently, the temperature was raised to 100°C over 60 minutes, maintained at 100°C for 180 minutes, and the reaction process was terminated. After the reaction process was completed, the mixture was cooled and dried by circulating nitrogen through the container while maintaining the temperature at 30°C to obtain spherical silica powder surface-treated with a silane coupling agent. The physical properties of the obtained surface-treated silica powder were measured. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0171] [Example 2-2]

[0172] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that silica powder 2 was used instead of silica powder 1. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0173] [Examples 2-3]

[0174] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that no surface treatment agent was used for 100 parts by mass of silica powder 1, and the silane coupling agent was changed to 0.5 parts by mass of silane coupling agent (KBM-573 manufactured by Shin-Etsu Silicon). Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0175] [Examples 2-4]

[0176] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 0.7 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 3. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0177] [Examples 2-5]

[0178] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.02 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 1.2 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 4. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0179] [Examples 2-6]

[0180] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.08 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 4.0 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 5. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0181] [Example 2-7]

[0182] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 0.3 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 6. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0183] [Examples 2-8]

[0184] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 0.3 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 7. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0185] [Example 2-9]

[0186] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.03 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 1.5 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 8. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0187] [Example 2-10]

[0188] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.05 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 2.5 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 9. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0189] [Example 2-11]

[0190] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.03 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 1.5 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0191] [Example 2-12]

[0192] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 0.2 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 1. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0193] [Example 2-13]

[0194] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 1.2 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 1. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0195] [Example 2-14]

[0196] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 2.4 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for 100 parts by mass of silica powder 1. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0197] [Comparative Example 2-1]

[0198] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that silica powder A prepared in Comparative Example 1-1 was used instead of silica powder 1. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0199] [Comparative Example 2-2]

[0200] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that silica powder B prepared in Comparative Example 1-2 was used instead of silica powder 1. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0201] [Comparative Example 2-3]

[0202] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that silica powder C prepared in Comparative Examples 1-3 was used instead of silica powder 1. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0203] [Comparative Example 2-4]

[0204] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that commercially available spherical silica powder D of Comparative Examples 1-4 was used instead of silica powder 1, and 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 0.9 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for every 100 parts by mass of spherical silica powder D. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0205] [Comparative Example 2-5]

[0206] Surface-treated silica powder was prepared and measured in the same manner as in Example 2-1, except that commercially available spherical silica powder D of Comparative Examples 1-4 was used instead of silica powder 1, and 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Silicon) and 0.9 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Silicon) were used for every 100 parts by mass of spherical silica powder D. Table 3 shows the characteristics of the silica powder and the preparation conditions of the surface-treated silica powder, and Table 4 shows the physical properties of the surface-treated silica powder.

[0207]

[0208]

[0209] The silica powder of Examples 1-1 to 9, in which filtration was performed with a filter with a mesh size of 5 μm or less to remove independent particles exceeding 5 μm and the amount of independent particles exceeding 5 μm was reduced to less than 100 ppm, and the silica powder of Example 1-10, in which classification was performed with a wind classification device to remove independent particles exceeding 5 μm and the amount of independent particles exceeding 5 μm was reduced to less than 100 ppm, had good interstitial penetration.

[0210] Meanwhile, the spherical silica powders of Comparative Example 1-1, in which filter filtration was not performed and the amount of independent particles exceeding 5 μm was 100 ppm or more; Comparative Examples 1-2 to 3, in which filter filtration was performed with an eye size of 5 μm or more and the amount of independent particles exceeding 5 μm was 100 ppm or more; and Comparative Examples 1-4 to 5, in which commercial products were measured and the amount of independent particles exceeding 5 μm was 100 ppm or more, showed poor interstitial penetration.

[0211] Even in the case of surface-treated silica powder, regardless of the type of treatment agent, the silica powder of Examples 2-1 to 14, in which independent particles exceeding 5 μm are removed by filter filtration or air classification with a mesh size of 5 μm or less and the amount of independent particles exceeding 5 μm is less than 100 ppm, had good interstitial penetration.

[0212] Meanwhile, the spherical silica powders of Comparative Example 2-1, in which filter filtration was not performed and the amount of independent particles exceeding 5 μm was 100 ppm or more; Comparative Examples 2-2 to 3, in which filter filtration was performed with an eye size of 5 μm or more and the amount of independent particles exceeding 5 μm was 100 ppm or more; and Comparative Examples 2-4 to 5, in which commercial products were used and the amount of independent particles exceeding 5 μm was 100 ppm or more, showed poor interstitial penetration.

Claims

Claim 1 A silica powder comprising spherical silica particles, wherein the cumulative 50% diameter D50 based on volume, determined by laser diffraction scattering of a dispersion solution dispersed by the following dispersion method A, is 0.05 to 2.00 μm and the cumulative 100% diameter D100 based on volume is 5 μm or less; wherein the amount of particles exceeding 5 μm detected by dynamic image analysis of a dispersion solution dispersed by the following dispersion method B is 100 ppm or more and the amount of independent particles exceeding 5 μm is less than 100 ppm; wherein the spherical silica particles are surface-treated with a silane coupling agent, and the component amount of the silane coupling agent is 2.0 to 22.0 particles / nm 2 Silica powder characterized by the following: [Dispersion Method A] A method of dispersing a 5 mass% ethanol suspension of silica powder using an ultrasonic homogenizer at a frequency of 20 kHz for 5 minutes. [Dispersion Method B] A method of dispersing a 0.1 mass% aqueous suspension of silica powder using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes. Claim 2 delete Claim 3 In claim 1, silica powder having a ratio (D100 / D50) of a volume-based cumulative diameter D50 (㎛) obtained by laser diffraction scattering method and a volume-based cumulative diameter D100 (㎛) of D100 (㎛) of D100 being 1 or more and 5 or less. Claim 4 In claim 1, the silica powder in which the amount of coarse particles (V90) of the silica powder obtained by Equation (1) from the volume-based cumulative diameter D50 and volume-based cumulative diameter D90 obtained by laser diffraction scattering method is 10 or more and less than 100. V90={(D90-D50) / D50}×100 (1) Claim 5 A resin composition formed by dispersing the silica powder described in claim 1 in a resin. Claim 6 A dispersion formed by dispersing the silica powder described in claim 1 in a solvent.

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