Silicon dioxide powder, resin composition and dispersion

Abstract

The present invention relates to a silica powder which, when used as a resin filler for a semiconductor sealing material or the like, is capable of obtaining a resin composition resin having excellent filling characteristics and slit permeability, and which is capable of preparing a filler while obtaining a sufficient filling amount. The silica powder according to the present invention is characterized in that the volume-based cumulative 50% particle diameter (D50) measured by laser diffraction scattering is 0.05-2.00 [mu] m, and the amount of individual particles greater than 5 [mu] m detected by dynamic image analysis is less than 100 ppm.

Description

Technical Field

[0001] The present invention relates to silica powder, a resin composition, and a dispersion suitable for use as a filler for semiconductor encapsulation materials, liquid crystal sealants, thin films, and the like. Background Art

[0002] In recent years, with the development of high performance, miniaturization, and light weight of electronic devices, the semiconductor packaging forms mounted thereon have been continuously progressing in the direction of high integration, high density, and thinness. In order to make these semiconductor packages practical, in addition to the design of integrated circuits, it has become crucial to develop packaging materials suitable for this design.

[0003] For example, an epoxy resin is usually used as the underfill filled between a semiconductor chip and a wiring substrate. However, the epoxy resin, the semiconductor chip, and the wiring substrate each have different coefficients of linear expansion. Therefore, if the connecting portion cannot absorb stress, cracks may occur in the connecting portion. In order to suppress the generation of such cracks, fillers having a relatively small coefficient of linear expansion, such as silica, are usually dispersed in the underfill. At this time, in order to suppress the coefficient of linear expansion of the encapsulation material, it is necessary to increase the filling amount of the low-expansion-rate filler. In addition, when the underfill containing the filler is infiltrated into the gap, it is necessary to avoid generating voids, that is, the underfill needs to have sufficient slit permeability.

[0004] In order to increase the filling amount of the above-mentioned filler, hydrophilic dry-process silica powder having excellent dispersibility, a small particle size of dispersed particles, and a narrow particle size distribution during dispersion has been proposed (Patent Document 1). However, since the particle size of the dispersed particles of the silica powder described in Patent Document 1 is small, although no voids are generated when infiltrating into the gap, it causes a thickening effect on the resin composition, resulting in an increase in the viscosity of the resin composition filled with the silica powder. Therefore, there is still a problem that a sufficient filling amount cannot be obtained.

[0005] In addition, a method for improving the affinity with a resin by treating the surface of silica particles with high particle size uniformity with a silane coupling agent has been proposed. (For example, Patent Document 2). The silica particles described in Patent Document 2 indicate that when the surface of conventional silica particles is treated with an epoxy silane coupling agent, the silica particles self-aggregate after drying, and by further treating the surface with a nitrogen-containing compound, this self-aggregation of the silica particles can be suppressed, so that an increase in viscosity can be suppressed when filled into a resin. In addition, it has also been shown that by suppressing aggregation, a classification treatment is not required. However, although the number of aggregated particles has decreased, more than 0.1% of the coarse material that cannot pass through a sieve with a mesh size of 20 μm, which is defined as the coarse particle content, still remains. When used as a filler for an encapsulating material, voids are generated during the gap penetration process, and there is still a problem of causing molding defects. Prior Art Documents Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-152048 Patent Document 2: Japanese Unexamined Patent Application Publication No. 2019-189509 Summary of the Invention Technical Problem to be Solved by the Invention

[0007] Therefore, an object of the present invention is to provide silica powder having excellent slit permeability. More specifically, an object of the present invention is to provide silica powder capable of obtaining a sufficient filling amount while blending and adding a filler, thereby obtaining a resin composition resin having excellent filling properties and slit permeability. Means for Solving the Problem

[0008] In order to solve the above problems, the present inventors conducted in-depth research and found that: even silica powder containing large particle size particles (aggregated particles and independent particles) has a specific particle size distribution, and silica powder with a reduced number of large particle size independent particles has excellent filling properties when kneaded with a resin and filled with this silica powder, and the slit permeability of the resulting resin composition, and has high fluidity and good handleability in the powder state. In the present invention, an independent particle refers to a primary particle.

[0009] That is, the silica powder of the present invention is silica powder formed of spherical silica particles, and the volume-based cumulative 50% particle size, that is, D 50 measured by laser diffraction scattering method of the dispersion liquid after being dispersed by the following dispersion method A is 0.05 to 2.00 μm, and the volume-based cumulative 100% particle size, that is, D 100It is less than 5 μm, the amount of particles with a particle size exceeding 5 μm detected by the dynamic image analysis method in the dispersion liquid dispersed by the following dispersion method B is 100 ppm or more, and the amount of independent particles is less than 100 ppm. [Dispersion method A] A method of dispersing an ethanol suspension of 5% by mass silica powder for 5 minutes using an ultrasonic homogenizer with a frequency of 20 kHz. [Dispersion method B] A method of dispersing an aqueous suspension of 0.1% by mass silica powder for 30 minutes using an ultrasonic cleaner with a frequency of 40 kHz.

[0010] In the silica powder of the present invention, preferably, 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 per nm 2 .

[0011] In addition, the volume-based cumulative 50% particle size, that is, D 50 (μm), and the volume-based cumulative 100% particle size, that is, D 100 (μm), the ratio (D 100 / D 50 ) is preferably 1 or more and 5 or less, and the volume-based cumulative 50% particle size, that is, D 50 and the volume-based cumulative 90% volume particle size D 90 , the amount of coarse particles (V 90 ) of the spherical silica particles calculated by the formula (1) is preferably 10 or more and less than 100.

[0012] V 90 = { (D 90 - D 50 ) / D 50} × 100 (1) Advantages of the Invention

[0013] The silica powder of the present invention contains a specific amount of particles with a particle size exceeding 5 μm detected after being dispersed by dispersion method B, and thus has good handleability; the volume-based cumulative 50% particle size, that is, D 50 is within a specific particle size range, and the volume-based cumulative 100% particle size, that is, D 100 is less than a specific particle size; moreover, the independent particles with a particle size exceeding 5 μm detected after being dispersed by dispersion method B are reduced (the independent particles are less than a specific amount), so that the resin composition added with this silica powder can simultaneously have excellent filling properties and slit permeability. Therefore, it is suitable as a filling material for semiconductor packaging materials and semiconductor mounting adhesives. In particular, it is suitable as a filler for resins used in high-density packaging.

[0014] The silica powder contains individual particles and agglomerated particles. If, in the resin composition after adding the silica powder and kneading, there are a large number of individual particles and agglomerated particles with relatively large particle sizes (hereinafter also referred to as large-sized particles), then when using this resin composition as a filler for a semiconductor encapsulation material or a semiconductor mounting adhesive, during the gap penetration process, the penetration of the resin composition will be hindered by the large particles, easily resulting in poor slit permeability.

[0015] For the silica powder of the present invention, although it contains a specific amount of particles with a particle size exceeding 5 μm detected after being dispersed by the dispersion method B with weak shear applied, the resin composition using the silica powder of the present invention still has excellent slit permeability. This is because the volume-based cumulative 100% particle size, that is, D 100 is less than a specific particle size, and the number of individual particles with a particle size exceeding 5 μm detected after being dispersed by the dispersion method B is less than a specific number. It is speculated that this is because, in the unsheared state of the silica powder of the present invention before being added to the resin and kneaded, although it contains agglomerated particles and individual particles, in the resin composition after being kneaded with the resin and subjected to shear, the agglomerated particles are dispersed into smaller particles due to the strong shear. On the other hand, for the individual particles with a particle size exceeding 5 μm detected after being dispersed by the dispersion method B, their particle sizes will not change due to the strong shear, but in the silica powder of the present invention, their content has been reduced to less than a specific number, so they will not affect the slit permeability. Detailed Description of the Invention

[0016] The silica powder of the present invention will be described in detail below according to the examples.

[0017] [Silica Powder] The silica powder of the present invention is formed by spherical silica particles. The volume-based cumulative 50% particle size, that is, D 50 of the dispersion liquid of the silica powder dispersed by the following dispersion method A measured by the laser diffraction scattering method is 0.05 to 2.00 μm, and the volume-based cumulative 100% particle size, that is, D 100 is 5 μm or less. [Dispersion Method A] A method of dispersing a 5% by mass ethanol suspension of silica powder for 5 minutes using an ultrasonic homogenizer with a frequency of 20 kHz.

[0018] Since the dispersion method A uses a low-frequency ultrasonic homogenizer to apply strong shear, the measurement results by the laser diffraction scattering method obtained by dispersing with the dispersion method A reflect the state of the silica powder in the kneading process when filled into the resin. By measuring D of the silica powder dispersion liquid treated by the dispersion method A100 , it can be seen that no large particles are detected in the particle size distribution, indicating that the particles can be dispersed when strong shear is applied. However, due to the low detection sensitivity of the laser diffraction scattering method at the percentage level, it is impossible to detect and quantify the trace particles in the silica powder with a particle size exceeding D 100 .

[0019] Among them, the volume-based cumulative 50% particle size, that is, D 50 is 0.05 - 2.00 μm. When it is less than 0.05 μm, it will induce the thickening effect on the resin composition, resulting in an increase in the viscosity of the resin composition filled with this powder. Therefore, there is a tendency that a sufficient filling amount cannot be obtained. When it exceeds 2.00 μm, when the resin composition filled with this powder is permeated into the gap, due to the small difference in the narrowness of the gap and the particle size, the permeation is hindered, and there is a tendency to easily generate voids. If D 50 is within the range of 0.05 - 2.00 μm, even if a large amount of silica powder is filled into the resin, the low viscosity of the resin composition can be maintained.

[0020] In addition, the volume-based cumulative 100% particle size, that is, D 100 measured by the laser diffraction scattering method for the silica powder dispersion liquid dispersed by the dispersion method A is 5 μm or less, preferably less than 3 μm.

[0021] Among them, if the volume-based cumulative 100% particle size, that is, D 100 exceeds 5 μm, the existing particles will hinder the gap permeation and generate voids, resulting in molding defects. If D 100 is 5 μm or less, and the amount of independent particles exceeding 5 μm measured by the method described below is less than 100 ppm, then even if a large amount of silica powder is added to the resin, when the resin composition is permeated into the gap, good slit permeability can be exhibited. The volume-based cumulative D 100 is preferably 3 μm or less.

[0022] Furthermore, for the silica powder of the present invention, the amount of particles with a particle size exceeding 5 μm detected by the dynamic image analysis method for the dispersion liquid dispersed by the following dispersion method B is 100 ppm or more, and the amount of independent particles with a particle size exceeding 5 μm is less than 100 ppm. [Dispersion method B] A method of dispersing a 0.1 mass% water suspension of silica powder for 30 minutes using an ultrasonic cleaner with a frequency of 40 kHz.

[0023] As described above, in addition to measuring the particle size distribution of the dispersion liquid dispersed by the dispersion method A using strong shear, the amount of particles with a particle size exceeding 5 μm and the amount of independent particles with a particle size exceeding 5 μm in the dispersion liquid dispersed by the dispersion method B were measured by the dynamic image analysis method. Since the dispersion method B applies weak shear using a high-frequency ultrasonic cleaner, among the particles with a particle size exceeding 5 μm detected by the dynamic image analysis method, there are agglomerated particles dispersed into smaller particle sizes after applying strong shear and independent particles that cannot be dispersed even when strong shear is applied. The independent particles with a particle size exceeding 5 μm refer to particles that cannot be dispersed even when strong shear is applied. In addition, in order to distinguish and detect the agglomerated particles and independent particles, the images were filtered using parameters representing the shape. Among the "roundness" calculated in the dynamic image analysis, particles with a roundness of 0.90 or more are considered to have a high roundness and are judged to be independent spherical particles; while particles with a roundness less than 0.90 are judged to be amorphous and are identified as agglomerated particles with a high possibility of being formed by primary particle aggregation.

[0024] The amount of particles with a particle size exceeding 5 μm detected by the dynamic image analysis method for the silica powder is 100 ppm or more. As described above, the particles detected here include both agglomerated particles formed by primary particle aggregation and independent particles. If the amount of these particles is 100 ppm or more, the fluidity of the silica powder can be improved, and furthermore, the handling property when adding the silica powder to the resin can be improved.

[0025] On the other hand, the amount of independent particles with a particle size exceeding 5 μm is less than 100 ppm. It is preferably less than 50 ppm, more preferably less than 10 ppm. If the amount of independent particles with a particle size exceeding 5 μm is 100 ppm or more, the existing independent particles may not be able to penetrate into the gaps, resulting in voids and causing molding defects. If it is less than 100 ppm, even when a large amount of spherical silica particles are added to the resin, good slit permeability can be exhibited when the resin composition penetrates into the gaps.

[0026] That is, when the amount of particles with a particle size exceeding 5 μm detected by the dynamic image analysis method in the dispersion liquid dispersed by the dispersion method B is more than 100 ppm, and the amount of independent particles with a particle size exceeding 5 μm is less than 100 ppm, in the silica powder of the present invention before shearing is applied, both the agglomerated particles with a particle size exceeding 5 μm and the independent particles with a particle size exceeding 5 μm are more than 100 ppm. Therefore, the fluidity is high and the handling property is good when adding the silica powder to the resin. After the silica powder is dispersed in the resin by applying strong shear, the agglomerated particles with a particle size exceeding 5 μm are dispersed due to the strong shear, and the amount of independent particles with a particle size exceeding 5 μm remains less than 100 ppm. Even when a large amount of spherical silica particles are added to the resin, good slit permeability can be exhibited when the resin composition penetrates into the slit. In addition, when the amount of particles with a particle size exceeding 3 μm detected by the dynamic image analysis method in the dispersion liquid dispersed by the dispersion method B is more than 100 ppm, and the amount of independent particles with a particle size exceeding 3 μm is less than 100 ppm, in the silica powder of the present invention before shearing is applied, both the agglomerated particles with a particle size exceeding 3 μm and the independent particles with a particle size exceeding 3 μm are more than 100 ppm. Therefore, the fluidity is high and the handling property is good when adding the silica powder to the resin. After the silica powder is dispersed into the resin by applying strong shear, the agglomerated particles with a particle size exceeding 3 μm are dispersed due to the strong shear, and the amount of independent particles with a particle size exceeding 3 μm remains less than 100 ppm. Even when a large amount of spherical silica particles are added to the resin, the time required for slit penetration can be shortened and good slit permeability can be exhibited when the resin composition penetrates into the slit.

[0027] In addition, for the particles of the silica powder with a particle size of 5 μm or less detected by the dynamic image analysis method, the roundness is preferably 0.90 or more. When the roundness reaches 0.90 or more, the proportion of spherical particles increases and the fluidity improves, so that good slit permeability can be exhibited.

[0028] For the particles of the silica powder with a particle size of 5 μm or less detected by the dynamic image analysis method, the aspect ratio (length-to-width ratio) is preferably 0.92 or more. When the aspect ratio reaches 0.92 or more, the proportion of spherical particles increases and the fluidity improves, and good slit permeability can be exhibited.

[0029] In the present invention, the spherical silica particles can be surface-treated with a silane coupling agent. The component amount of the silane coupling agent is preferably 2.0 to 22.0 per nm 2 , more preferably 4.0 to 18.0 per nm 2 . When the component amount of the silane coupling agent is 2.0 to 22.0 per nm 2 , the contact between the reactive hydroxyl groups on the surface of the silica particles and the resin can be sufficiently blocked. When the component amount is 2.0 per nm2 When it is above, the reactive hydroxyl groups on the surface of the silica particles are blocked by the organic resin, and the affinity has a tendency to increase; while at 22.0 per nm 2 When it is below, there is less excess silane coupling agent, and the dispersibility of the silica particles has a tendency to increase.

[0030] The particle size distribution of the silica powder can be obtained by the volume-based particle size distribution of laser diffraction scattering method, that is, the cumulative 50 volume% particle size D 50 and D as the maximum particle size 100 Their ratio (D 100 / D 50 ) is used to represent. (D 100 / D 50 ) is preferably 1 or more and 5 or less. If D 100 / D 50 ) is 1 or more and 5 or less, the spherical silica particles are likely to fill in the resin in a form close to close packing. Even if a large amount of spherical silica particles are filled, the resin not contained in the particle gaps will increase, so that the low viscosity of the resin composition can be maintained.

[0031] Furthermore, the amount of coarse particles of the silica powder can be represented by V obtained by the following formula (1) 90 .

[0032] V 90 ={(D 90 -D 50 ) / D 50}×100 (1) D 50 : The cumulative 50 volume% particle size of the volume-based particle size distribution obtained by the laser diffraction scattering method D 90 : The cumulative 90 volume% particle size of the volume-based particle size distribution obtained by the laser diffraction scattering method V 90 is preferably 10 or more and less than 100, more preferably 10 to 95, and further preferably 20 to 90. When V 90 is 10 or more and less than 100, good gap permeability can be obtained when the resin composition penetrates into the gaps.

[0033] [Use] The use of the silica powder of the present invention is not particularly limited. For example, it can be used as a filler for semiconductor packaging materials or semiconductor mounting adhesives, a filler for chip mounting films or chip mounting pastes, or a filler for resin compositions such as insulating films of semiconductor packaging substrates. In particular, the spherical silica particles obtained in the present invention are suitable for use as fillers in resin compositions for high-density packaging.

[0034] Furthermore, the silica powder of the present invention can also be used as abrasive grains for CMP (Chemical Mechanical Polishing), abrasive grains for grinding wheels used in grinding, external additives for toners, additives for liquid crystal sealing materials, dental filling materials, or can also be used as an inkjet coating material.

[0035] [Method for manufacturing silica powder] Next, the method for manufacturing the silica powder of the present invention will be described.

[0036] The silica-based spherical particles are classified to obtain silica powder composed of spherical silica particles. This will be described in detail below.

[0037] <Silica-based spherical particles> 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 measured by the laser diffraction scattering method.

[0038] In addition, as the silica-based spherical particles, a wet silica-based spherical particle dispersion obtained by the sol-gel method can also be used. Among them, the sol-gel method is to hydrolyze and polycondense a silicate in a reaction medium composed of water containing a catalyst and an organic solvent to generate a silica sol, and then gelate it to obtain a wet silica-based spherical particle dispersion.

[0039] In addition, as the silica-based spherical particles, dry silica-based spherical particles obtained by the flame method can also be used. Among them, the flame method is to generate by burning a silicon compound, and grow and agglomerate it in and near the flame to obtain the dry silica-based spherical particles. For example, in International Publication No. 2020 / 175160, a method for preparing silica by burning a silicon compound is shown. A burner having a concentric multi-tube structure with three or more tubes is used, and a reactor with a jacket part for cooling is provided around it. By adjusting the combustion conditions and cooling conditions of the flame, silica powder having a cumulative 50% mass particle diameter of 300 nm or more and 500 nm or less in the mass-based particle size distribution obtained by the centrifugal sedimentation method can be obtained.

[0040] <Classification treatment> By classifying spherical silica particles, spherical silica particles with fewer independent particles can be obtained. For example, the wet silica spherical particle dispersion is wet-filtered to remove the independent particles contained therein. That is, by filtering the wet silica spherical particle dispersion, the independent particles can be separated together with reaction residues, etc. on the filter medium. If there are generated adhered particles or agglomerates, they can also be separated. Among them, as the filter medium, in the wet filtration membrane, a filter medium with a pore size of 5 μm or less can be used without particular limitation on the type, and a filter medium with a pore size of 3 μm or less is preferably used. If the pore size is too small, not only the filtration property decreases, but also the average particle size of the filtered silica particles deviates from the above range and changes greatly. Therefore, the lower limit of the pore size is usually 1 μm, depending on the average particle size of the required powder. The material of the filter membrane is not particularly limited. For example, it can be resin-made (such as polypropylene, PTFE, etc.) or metal-made. From the perspective of preventing the mixing of metal impurities, a resin-made filter membrane is preferably used.

[0041] In addition, since the dry silica spherical particles are powders in terms of the manufacturing method, they can also be dispersed in a solvent and wet-filtered. At this time, the solvent is not particularly limited, but a solvent in which the dry silica particles are easily dispersed is preferably selected.

[0042] In addition, for example, a classification treatment using inertial force such as a liquid cyclone or air classification can also be used. The medium at this time is not particularly limited, but from the viewpoint of good dispersibility in the medium, for wet silica spherical particles, a liquid is preferably used; for dry silica spherical particles, air is preferably used.

[0043] <Separation treatment> In this embodiment, the spherical silica particles obtained by classification can be subjected to solid-liquid separation and recovered as a filter cake if necessary. In addition, solid-liquid separation can also be carried out after adding a flocculant to form weak aggregates. By adding a flocculant, solid-liquid separation can be achieved, facilitating recovery. The filtration method is not particularly limited. For example, well-known methods such as vacuum filtration, pressure filtration, and centrifugal filtration can be adopted.

[0044] In addition, the added flocculant is not particularly limited, but from the perspective of preventing it from being mixed into the obtained spherical silica particles, a compound containing no metal element components is preferably used as the flocculant, such as carbon dioxide, ammonium carbonate, ammonium bicarbonate, and ammonium carbamate.

[0045] <Drying treatment> In this embodiment, the filter cake containing spherical silica particles obtained by the separation treatment can be dried if necessary to obtain silica powder composed of spherical silica particles.

[0046] The drying method is not particularly limited, and known methods such as air drying and reduced-pressure drying can be used. However, since drying under reduced pressure is more likely to cause breakage than drying at atmospheric pressure, reduced-pressure drying is preferably used.

[0047] 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. When the drying temperature is in the range of 35 to 200 °C, it is beneficial to obtain silica powder that is easy to break.

[0048] <Calcination treatment> In this embodiment, the silica powder containing spherical silica particles obtained by the drying treatment can be calcined if necessary.

[0049] For the silica powder containing spherical silica particles after drying, the dispersion medium adsorbed in the particles has not been completely removed, and silanol groups remain. In particular, pores exist in the silica particles using wet-process silica-based spherical particles. In order to highly remove the dispersion medium in the particles and eliminate the silanol groups to obtain dense silica, depending on the use, further calcination treatment is preferably performed. That is, for the silica particles treated through this calcination process, it is also preferred that not only the amount of silanol groups on the particle surface is reduced, but also the remaining dispersion medium in the particles is removed. When the solvent remaining in the particles is used as a filler for a resin, heating will generate bubbles, etc., resulting in a decrease in the yield. This is particularly significant in applications such as semiconductor encapsulation materials and liquid crystal sealants with a high filling rate. Therefore, in the manufacture of silica particles for use in semiconductor encapsulation materials and liquid crystal sealants in particular, it is preferred to set this process.

[0050] If the calcination temperature of the above-mentioned calcination treatment is too low, it is difficult to remove the dispersion medium component, and if it is too high, it will cause melting and adhesion of the silica particles. Therefore, it is preferably carried out at 300 to 1300 °C, more preferably at 600 to 1200 °C. The calcination time is not particularly limited as long as the remaining dispersion medium is removed, but if it is too long, the production efficiency will be reduced. Therefore, after heating to the target calcination temperature, it is sufficient to carry out calcination for 0.5 to 48 hours, more preferably in the range of 2 to 24 hours. The atmosphere during calcination is not particularly limited, and it can be carried out under an inert gas such as argon or nitrogen, or in an atmospheric environment.

[0051] The silica powder of the present invention can be subjected to a crushing treatment by known crushing means if necessary to further reduce agglomerates before use. The crushing method is not particularly limited, and for example, known methods such as a ball mill and a jet mill can be used.

[0052] [Surface treatment based on a silane coupling agent] Spherical silica particles can be surface-treated with a silane coupling agent. Details are as follows.

[0053] <Silane coupling agent> The silane coupling agent can be exemplified by a compound represented by the following formula (2).

[0054] R n –Si–X (4–n) (2) 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.

[0055] In addition, as the above X, alkoxy groups having 1 to 3 carbon atoms such as methoxy, ethoxy, and propoxy and / or halogen atoms such as chlorine atoms can be cited, and methoxy and / or ethoxy are preferred. It should be noted that when n is 1 or 2, multiple Xs can be the same or different, but are preferably the same. In addition, n is an integer from 1 to 3, preferably 1 or 2, and particularly preferably 1.

[0056] As the silane coupling agent exemplified by the above formula (2), the following can be cited: Methyltrimethoxysilane, methyltriethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-acryloxytrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N,N-dimethyl-3-aminopropyltrimethoxysilane, N,N-diethyl-3-aminopropyltrimethoxysilane, 4-styryltrimethoxysilane, etc.

[0057] <Surface treatment agent (other additives)> In addition, in addition to the silane coupling agent, at least one surface treatment agent selected from silicone oils, siloxanes, and / or silazanes can be added. The surface treatment agent can be added simultaneously with the silane coupling agent, or the silane coupling agent can be added after adding the surface treatment agent. Further, the surface treatment agent can also be added after adding the silane coupling agent. Thus, spherical silica particles having various surface properties can be obtained. For example, spherical silica particles composed of trimethylsilyl and epoxy groups can be easily obtained.

[0058] The usage amount of the surface treatment agent, if it is silicone oil, is preferably 0.05 to 80 parts by mass, more preferably 0.1 to 60 parts by mass, and most preferably 1 to 20 parts by mass per 1 part by weight of spherical silica particles. Similarly, if it is a siloxane, it is preferably 0.001 to 40 parts by mass, more preferably 0.003 to 30 parts by mass, and most preferably 0.005 to 20 parts by mass per 1 part by weight of spherical silica particles. Similarly, if it is a silazane, it is preferably 0.001 to 40 parts by mass, more preferably 0.003 to 30 parts by mass, and most preferably 0.005 to 20 parts by mass per 1 part by weight of silica powder.

[0059] <Mixing> The spherical silica particles and the silane coupling agent are mixed by a conventionally well-known method. For example, the spherical silica particles are put into a mixing container, and a prescribed amount of the silane coupling agent is added in a state where the spherical silica particles are fluidized by methods such as shaking or stirring, for example, by dropping or spraying. For example, silica powder is added into a container, and stirring is started by the rotation of a stirring blade. Then, a silane coupling agent is added using a peristaltic pump. The addition speed can be appropriately adjusted according to the addition amount.

[0060] After adding the silane coupling agent, it is preferable to continue stirring for at least 10 minutes. By continuing stirring, the silane coupling agent can be uniformly attached to the surface of the spherical silica particles.

[0061] As the mixing container, for example, a Henschel type mixing device equipped with a stirring blade or a mixing blade, a Lodige mixer, etc., an air current stirrer that mixes by an air current, a V-type stirrer that mixes by rotating or shaking the container body, a double cone type mixing device, and a rocking mixer, etc. can be used.

[0062] <Heat treatment> By heat treatment, a part of the added silane coupling agent reacts (i.e., chemically binds) with the surface of the silica particles, while the remaining silane coupling agent does not chemically bind and remains on the surface of the silica particles (i.e., physically adsorbed). If the temperature for heat treatment is too low, the reaction process is slow, resulting in a decrease in production efficiency; if it is too high, the silane coupling agent and the surface treatment agent will decompose, or the formation of agglomerates will be promoted due to a rapid polymerization reaction. Therefore, although it depends on the silane coupling agent used, etc., the reaction is usually carried out at a temperature of 25 to 300 °C, preferably 40 to 250 °C.

[0063] The heat treatment time can be appropriately determined according to the reactivity of the silane coupling agent used, etc. Usually, a sufficient reaction rate can be obtained within 1 hour or more and 500 hours or less. In addition, if the heat treatment can be carried out in the mixing container used for mixing, the mixed powder can be directly used in the heat treatment device.

[0064] <Drying treatment> The drying temperature is not particularly limited, but if the temperature is too high, the silane coupling agent component that has not undergone chemical bonding (physical adsorption) will volatilize and thus be removed from the spherical silica particles, so it is not preferred; if the temperature is too low, by-products cannot be sufficiently removed. Therefore, the drying temperature is preferably 25 to 200 °C, more preferably 25 to 180 °C, and further preferably 25 to 150 °C. Drying at 25 °C or higher can sufficiently remove the by-products generated when the silane coupling agent reacts with the surface of the silica particles.

[0065] The equipment used for drying is not particularly limited, and existing well-known drying equipment can be used. In addition, if drying can be carried out in the reaction vessel used during the heat treatment, the treated powder can be directly dried in the device.

[0066] The pressure inside the device during drying is preferably above atmospheric pressure. Specifically, it is preferably 1000 hPa or higher. By drying under a pressure above atmospheric pressure, unreacted silane coupling agents can be sufficiently removed. If the pressure is 1000 hPa or higher, by-products can be sufficiently removed without volatilizing the physically adsorbed silane coupling agent component.

[0067] The drying time is not particularly limited and can be appropriately selected according to the drying conditions such as drying temperature and pressure; generally, it takes about 1 to 48 hours to obtain surface-treated silica powder with by-products removed.

[0068] [Dispersion] The silica powder of the present invention can be dispersed in a solvent to form a dispersion. The solvent used for dispersing the silica powder is not particularly limited as long as it is a solvent that can easily disperse the silica powder.

[0069] Solvents that can be used include, for example, water and organic solvents such as alcohols, ethers, and ketones. As the alcohols, for example, methanol, ethanol, and 2-propanol can be used. A mixed solvent of water and one or more of the organic solvents can also be used as the solvent. In addition, various additives such as dispersants, thickeners, wetting agents, defoaming agents, or acidic or basic pH regulators can be added to improve the stability and dispersibility of the silica powder. In addition, the pH of the dispersion is not limited.

[0070] The uses of the dispersion include filling for semiconductor encapsulation materials and semiconductor mounting adhesives. The dispersion, that is, the silica powder pre-dispersed in a solvent, can be easily dispersed in a resin. For example, after mixing the resin and the dispersion and removing the solvent, a bottom filler with good dispersion of the filler can be easily prepared.

[0071] [Resin composition] There is no particular limitation on the type of resin used to prepare the silica powder in order to prepare the resin composition of the present invention. The type of resin can be appropriately selected according to the desired use, and examples thereof include epoxy resins, acrylic resins, silicone resins, olefin resins, polyimide resins, and / or polyester resins.

[0072] The method for producing the resin composition may be appropriately adopted by a known method, and the silica powder may be mixed with various resins and other components as necessary.

[0073] When the dispersion of the present invention is mixed with a resin, a resin composition in which the silica powder is dispersed in a better state in the resin can be obtained compared to mixing the silica powder in a dry state with the resin. The good dispersion state of the silica powder means that the agglomerated particles in the resin composition are reduced. Therefore, the viscosity characteristics and the slit permeability of the resin composition containing the silica powder of the present invention as a filler can be further improved.

[0074] The uses of the resin composition include semiconductor packaging materials and semiconductor mounting adhesives. The resin composition containing silica powder can suppress the linear expansion coefficient and is suitable for such uses.

[0075] [Summarize] As can be seen from the above description, the silica powder involved in the first aspect of the present invention is characterized in that: it is a silica powder composed of spherical silica particles, and the volume-based cumulative 50% particle size D measured by the laser diffraction scattering method after the dispersion is dispersed by the following dispersion method A 50 0.05 to 2.00 μm, and the volume-based cumulative 100% particle size D 100 and, the amount of particles with a particle size exceeding 5 μm detected by the dynamic image analysis method of the dispersion after dispersion by the following dispersion method B is above 100 ppm and the amount of independent particles with a particle size exceeding 5 μm is less than 100 ppm. [Dispersion method A] A method in which a 5 mass % ethanol suspension of silica powder is dispersed for 5 minutes using an ultrasonic homogenizer at a frequency of 20 kHz. [Dispersion method B] A method in which a 0.1 mass % aqueous suspension of silica powder is dispersed for 30 minutes using an ultrasonic cleaner at a frequency of 40 kHz.

[0076] According to such silica powder, when added to a resin, a high filling amount can be obtained, and at the same time, when penetrating into gaps, the penetration of the resin composition is not hindered, and excellent filling characteristics and narrow gap penetration can be achieved at the same time.

[0077] The silica powder according to the second form of the present invention is characterized in that: in the silica powder according to the first form, 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 per nm 2 .

[0078] The silica powder according to the third form of the present invention is characterized in that: in the silica powder according to the first form or the second form, the volume-based cumulative 50% particle size measured by the laser diffraction scattering method, that is, D 50 (μm) and the volume-based cumulative 100% particle size, that is, D 100 (μm) ratio (D 100 / D 50 ) is 1 or more and 5 or less.

[0079] The silica powder according to the fourth form of the present invention is characterized in that: in the silica powder according to the first form or the second form, based on the volume-based cumulative 50% particle size measured by the laser diffraction scattering method, that is, D 50 and the volume-based cumulative 90% particle size, that is, D 90 , the amount (V 90 ) of the coarse particles of the silica powder obtained by using the formula (1) is 10 or more and less than 100.

[0080] V 90 ={(D 90 -D 50 ) / D 50}×100 (1)

[0081] The resin composition according to the fifth form of the present invention is formed by dispersing the silica powder according to the first form or the second form in a resin.

[0082] The dispersion according to the sixth form of the present invention is formed by dispersing the silica powder according to the first form or the second form in a solvent. Examples

[0083] Hereinafter, examples in this embodiment mode will be listed for specific description, but the present invention is not limited by any of these examples.

[0084] The measurement and evaluation methods for each physical property of the silica powder are as follows.

[0085] (Volume-based particle size distribution by laser diffraction scattering method) Weigh approximately 0.5 g of silica powder into a 50 mL glass bottle, add 10 g of ethanol, and disperse it using an ultrasonic homogenizer (Sonifier 250 manufactured by Branson) under the conditions of a frequency of 20 kHz for 5 minutes. Then, use a laser diffraction scattering particle size distribution measuring device (LS 13 320 manufactured by Beckman Coulter) to measure the volume-based cumulative 50% particle size, namely D 50 (μm), the volume-based cumulative 100% particle size, namely D 100 (μm), and the volume-based cumulative 90 volume% particle size, namely D 90 (μm). Based on the obtained D 50 and D 90 , the amount of coarse particles (V 90 ) of the surface-treated silica powder is calculated by Equation (1).

[0086] V 90 ={(D 90 -D 50 ) / D 50}×100 (1)

[0087] (Dynamic image analysis method) (A method for measuring roundness, aspect ratio, the amount of particles with a particle size exceeding 5 μm, and the amount of independent particles with a particle size exceeding 5 μm by dynamic image analysis) (1) In the dynamic image analysis method, a dispersion in which silica powder is dispersed in pure water is used. The dispersion is 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 form a 0.1 mass% suspension, and then dispersing it using an ultrasonic cleaner with a frequency of 40 kHz for 30 minutes.

[0088] (2) The dispersion prepared in (1) is measured using a dynamic image analysis device (Partec analyzer manufactured by Hosokawa Micron Corporation) to obtain particle images in 0.015 mL of the dispersion. For the obtained particle images, "equivalent circular particle size d", "roundness", and "aspect ratio" are obtained through internal calculations of the device.

[0089] (3) When calculating the amount of particles with a particle size exceeding 5 μm and the amount of independent particles with a particle size exceeding 5 μm from the particle images obtained in (2), only select the particles with "equivalent circular diameter dd > 5 μm", and measure the number of particles with a particle size exceeding 5 μm. Further, the particles with a particle size exceeding 5 μm are identified by "circularity ≥ 0.9" and "aspect ratio ≥ 0.92", and the number of independent particles with a particle size exceeding 5 μm is measured. Among them, using the equivalent circular diameter d [μm] of the particles, according to the following calculation method in (4), the particle amounts W [ppm] of the particles with a particle size exceeding 5 μm and the independent particles with a particle size exceeding 5 μm are calculated respectively. When calculating the amount of particles with a particle size exceeding 3 μm and the amount of independent particles with a particle size exceeding 3 μm, except for only selecting the particles with "equivalent circular diameter d > 3 μm" from the particle images obtained in (2), the rest is the same as the above method.

[0090] (4) Using the equivalent circular diameter d [μm] obtained by dynamic image analysis, the mass w [g] of each particle is calculated according to Equation (i). ρ uses the true density ρ = 2.2 [g·m -3 value. w = ρ × π / 6 × (d ÷ 10 6 ) 3 (i)

[0091] Perform this operation on each particle detected by dynamic image analysis to calculate the weight of each particle. Take their sum as the total weight ws [g], and according to Equation (ii), obtain the particle amount W [ppm] in the measured spherical silica particle amount. W = ws / (0.015 × (0.1 / 100)) (ii)

[0092] In addition, the detection limit of this measurement method is calculated by measuring 0.015 mL of the dispersion liquid of standard particle 1 (4206A manufactured by Thermo Fisher Scientific) with a known amount of 10 ppm added to the dispersion liquid prepared in the above (1). The amount of independent particles obtained by measuring the dispersion liquid with the added standard particles represents the detected amount of the standard particles. From this result, the detection limit of the particle amount with a particle size exceeding 5 μm is determined to be 10 ppm. In addition, similarly, the dispersion liquid of standard particle 2 (4204A manufactured by Thermo Fisher Scientific) is measured, and the detection limit of the particle amount with a particle size exceeding 3 μm is determined to be 10 ppm.

[0093] (Method for Measuring the Amount of Silane Coupling Agent Component in Silica Powder) 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) are used to calculate the component amount of the silane coupling agent (pieces / nm 2 ).

[0094] Component amount of silane coupling agent (pieces / nm 2 ) = Carbon content of spherical silica particles (mass%) / 100 / 12 (atomic weight of carbon) / {Number of carbon atoms of silane coupling agent - N} × Avogadro's constant (pieces / mol) / BET specific surface area of silica powder (m 2 / g) / 10 18 (In the formula, the number of carbon atoms of the silane coupling agent is the number of carbon atoms in the molecular formula of the silane coupling agent used. For example, when using KBM-403 manufactured by Shin-Etsu Silicone Co., Ltd., since this silane coupling agent has the molecular formula C 9 H 20 O 5 Si, the number of carbon atoms of the silane coupling agent is 9. N is the number of carbon atoms of the hydrolyzable group X of the silane coupling agent × 2. For example, when X is methoxy, N is 2; when X is ethoxy, N is 4. Avogadro's constant is 6.02×10 23 (pieces / mol).)

[0095] (Carbon content) The carbon content (mass%) was measured using a total nitrogen and total carbon measurement device (Sumigraph NC-TR22 manufactured by JNC Corporation). In addition, the amount of silica sample measured was 50 - 100 mg.

[0096] (BET specific surface area) The BET specific surface area S (m 2 / g) was measured using a specific surface area measurement device (SA-1000 manufactured by Shibata Rikagaku Corporation) by the nitrogen adsorption BET single-point method.

[0097] (Evaluation of the gap permeability of silica powder) 36 g of silica powder was added to a mixture of 17 g of bisphenol F type epoxy resin (YDF-8170C manufactured by Nippon Steel Chemical & Material Co., Ltd.) and 7 g of amine curing agent (KARAHARD A-A manufactured by Nippon Kayaku Co., Ltd.) and hand-stirred. The resin composition after hand-stirring was premixed using a planetary mixer (Awatori Rentaro AR-500 manufactured by THINKY) (mixing: 1000 rpm, 8 minutes, defoaming: 2000 rpm, 2 minutes). The resin composition after premixing was stored in a constant temperature water bath at 25°C and then kneaded using a three-roll mill (BR-150HCV manufactured by IMEX Co., Ltd., roll diameter being 63.5). The kneading conditions were a kneading temperature of 25°C, a roll gap of 20 μm, and 8 kneading passes. The obtained resin composition was defoamed under reduced pressure for 30 minutes using a vacuum pump (TSW-150 manufactured by Sato Vacuum Co., Ltd.) to obtain a kneaded resin composition. The kneaded resin composition was dropped at the inlet of a gap where two pieces of glass were superposed in advance to form a 30-μm gap and heated to 110°C to conduct a high-temperature permeability test. The presence or absence of flow marks was evaluated by visual appearance. If no flow marks were seen, the gap permeability was considered good; if flow marks were seen, the gap permeability was judged to be poor. Among them, if the gap permeability was good, the silica powder was considered to have excellent filling properties and viscosity characteristics.

[0098] [Example 1-1] 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 as a reaction medium, the reaction temperature was set at 40 °C, and stirring was carried out. Subsequently, a mixture of 0.2 parts by mass of tetraethoxysilane, 0.4 parts by mass of methanol, and 0.1 parts by mass of isopropanol was used as a raw material and introduced into the reaction medium to prepare silica seed particles. Then, a raw material of 100 parts by mass of tetramethoxysilane and 28.5 parts by mass of methanol was supplied to the reaction medium, and at the same time 42.8 parts by mass of ammonia water (25 mass%) was supplied to grow and synthesize sol-gel silica particles. After the supply was completed, stirring was continued for 1 hour to obtain a dispersion of silica-based spherical particles with an average particle size of 1.0 μm. The dispersion of silica-based spherical particles was wet-filtered using a polypropylene filter membrane with a pore size of 3 μm to remove independent particles. After that, 0.9 parts by mass of dry ice was added and left for 20 hours. After 20 hours, the sol-gel silica particles had settled, and solid-liquid separation was carried out using quantitative filter paper (retaining a particle size of 6 μm) to obtain a filter cake. Then, vacuum drying was carried out at 100 °C for 15 hours. Next, calcination was carried out at 800 °C for 10 hours in an air atmosphere. Then, crushing treatment was carried out using a jet mill to obtain silica powder 1. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0099] [Example 1-2] In wet filtration, except that the pore size of the polypropylene filter was changed from 3 μm to 5 μm, silica powder 2 was prepared and measured in the same manner as in Example 1-1. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0100] [Example 1-3] 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 the 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. After that, silica powder 3 was prepared and measured in the same method as in Example 1-1. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0101] [Example 1-4] In Example 1-1, the reaction medium was changed to 83.3 parts by mass of methanol, 33.3 parts by mass of isopropanol, and 27.8 parts by mass of ammonia water (25% by mass). Subsequently, the raw materials for preparing silica seed particles were changed to 3.3 parts by mass of tetraethoxysilane, 7.8 parts by mass of methanol, and 2.2 parts by mass of isopropanol, and silica seed particles were prepared. Next, the raw materials after preparing silica seed particles were changed to 100 parts by mass of tetramethoxysilane, 27.8 parts by mass of methanol, and 44.4 parts by mass of ammonia water (25% by mass). Thereafter, silica powder 4 was prepared in the same manner as in Example 1-1 and measured. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0102] [Example 1-5] 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% by 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% by mass) was added as raw materials to the reaction medium to grow and synthesize sol-gel silica particles. Thereafter, silica powder 5 was prepared in the same manner as in Example 1-1 and measured. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0103] [Example 1-6] 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% by 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, and silica seed particles were prepared. Thereafter, silica powder 6 was prepared in the same manner as in Example 1-1 and measured. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0104] [Example 1-7] Except that during wet filtration, the pore size of the polypropylene filter was changed from 3 μm to 5 μm, silica powder 7 was prepared and measured in the same manner as in Example 1-6. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0105] [Example 1-8] 5 parts by mass of dry-process silica spherical particles with an average particle diameter of 0.38 μm (Silphill Nss-40D manufactured by Tokuyama Corporation) were added to 100 parts by mass of pure water to prepare a dispersion of dry-process silica spherical particles. The dispersion of dry-process silica spherical particles was wet-filtered using a polypropylene filter with a pore size of 3 μm to remove independent particles, and silica particles 8 were prepared and measured. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0106] [Example 1-9] Except for using dry-process silica spherical particles with an average particle diameter of 0.24 μm (Silphill Nss-24D manufactured by Tokuyama Corporation) instead of dry-process silica spherical particles with an average particle diameter of 0.38 μm (Silphill Nss-40D manufactured by Tokuyama Corporation), silica powder 9 was prepared and measured in the same manner as in Examples 1-8. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0107] [Example 1-10] The dry-process silica spherical particles with an average particle diameter of 0.38 μm (Silphill Nss-40D manufactured by Tokuyama Corporation) were classified by an air classification device, and silica powder 10 was prepared and measured. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0108] [Comparative Example 1-1] Except for not performing wet filtration using a polypropylene filter with a pore size of 3 μm, silica powder A was prepared and measured in the same manner as in Example 1-1. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0109] [Comparative Example 1-2] During wet filtration, except for changing the pore size of the polypropylene filter from 3 μm to 7 μm, silica powder B was prepared and measured in the same manner as in Example 1-1. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0110] [Comparative Example 1-3] In wet filtration, silica powder C was prepared and measured in the same manner as in Example 1-1, except that the pore size of the polypropylene filter was changed from 3 μm to 10 μm. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0111] [Comparative Example 1-4] A commercially available spherical silica powder D was measured. Table 1 shows the properties of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0112] [Comparative Example 1-5] A commercially available spherical silica powder E was measured. Table 1 shows the properties of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0113]

Table 1

[0114]

Table 2

[0115] [Example 2-1] The silica powder 1 prepared in Example 1-1 was put into a mixing container and stirring was started. Subsequently, for 100 parts by mass of the silica powder 1, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.5 part by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used as surface treatment agents and supplied by a peristaltic pump (SJ-1211II-H manufactured by ATTA). Stirring was continued directly after the supply, and mixing was carried out for 15 minutes. After mixing, while continuing to stir, the temperature was raised from room temperature to 40 °C over 20 minutes, and then maintained at 40 °C for 60 minutes. After that, the temperature was raised to 100 °C over 60 minutes and maintained at 100 °C for 180 minutes to complete the reaction process. After the reaction was completed, it was cooled and dried by introducing nitrogen gas into the container under the condition of maintaining at 30 °C, and spherical silica powder surface-treated with a silane coupling agent was obtained. The physical properties of the obtained surface-treated silica powder were measured. Table 3 shows the properties 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.

[0116] [Example 2-2] Except that silica powder 2 was used instead of silica powder 1, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0117] [Example 2-3] Except that for 100 parts by mass of silica powder 1, no surface treatment agent was used and the silane coupling agent was replaced with 0.5 part by mass of a silane coupling agent (KBM-573 manufactured by Shin-Etsu Quartz Co., Ltd.), the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0118] [Example 2-4] Except that for 100 parts by mass of silica powder 3, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.7 part by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0119] [Example 2-5] Except that for 100 parts by mass of silica powder 4, 0.02 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.2 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0120] [Example 2-6] Except that for 100 parts by mass of silica powder 5, 0.08 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 4.0 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0121] [Example 2-7] Except that for 100 parts by mass of silica powder 6, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.3 part by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0122] [Example 2-8] Except that for 100 parts by mass of silica powder 7, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.3 part by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0123] [Example 2-9] Except that for 100 parts by mass of silica powder 8, 0.03 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.5 part by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0124] [Example 2-10] Except that for 100 parts by mass of silica powder 9, 0.05 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 2.5 part by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0125] [Example 2-11] Except that for 100 parts by mass of silica powder 10, 0.03 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.5 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0126] [Example 2-12] Except that for 100 parts by mass of silica powder 1, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.2 part by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0127] [Example 2-13] Except that for 100 parts by mass of silica powder 1, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.2 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0128] [Example 2-14] Except that for 100 parts by mass of silica powder 1, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 2.4 parts by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0129] [Comparative Example 2-1] Except that silica powder A prepared in Comparative Example 1-1 was used instead of silica powder 1, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0130] [Comparative Example 2-2] Except for using the silica powder B prepared in Comparative Example 1-2 to replace silica powder 1, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0131] [Comparative Example 2-3] Except for using the silica powder C prepared in Comparative Example 1-3 to replace silica powder 1, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0132] [Comparative Example 2-4] Except for using the commercially available spherical silica powder D in Comparative Example 1-4 to replace silica powder 1, and for 100 parts by mass of the spherical silica powder D, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.9 part by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0133] [Comparative Example 2-5] Except for using the commercially available spherical silica powder D in Comparative Example 1-4 to replace silica powder 1, and for 100 parts by mass of the spherical silica powder D, 0.01 part by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.9 part by mass of a silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used, the surface-treated silica powder was prepared and measured in the same manner as in Example 2-1. Table 3 shows the properties 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.

[0134]

Table 3

[0135]

Table 4

[0136] Examples 1-1 to 9 in which filtration is performed using a filter with a pore size of 5 μm or less to remove independent particles larger than 5 μm and the amount of independent particles larger than 5 μm is controlled to 100 ppm or less, and silica powder of Example 1-10 in which classification is performed by an air classification device to remove independent particles larger than 5 μm and the amount of independent particles larger than 5 μm is controlled to 100 ppm or less have good slit permeability.

[0137] On the other hand, Comparative Example 1-1 in which no filtration operation is performed and the amount of independent particles larger than 5 μm reaches 100 ppm or more; Comparative Examples 1-2 to 3 in which filtration is performed using a filter with a pore size of 5 μm or more and the amount of independent particles larger than 5 μm reaches 100 ppm or more; and spherical silica powder of Comparative Examples 1-4 to 5 in which commercially available products are measured and the amount of independent particles larger than 5 μm reaches 100 ppm or more have poor slit permeability.

[0138] Among the surface-treated silica powders, regardless of the type of treatment agent, the silica powders of Examples 2-1 to 14 in which filtration through a filter with a pore size of 5 μm or less or air classification is performed to remove independent particles larger than 5 μm and the amount of independent particles larger than 5 μm is controlled to 100 ppm or less have good slit permeability.

[0139] On the other hand, Comparative Example 2-1 in which no filtration operation is performed and the amount of independent particles larger than 5 μm reaches 100 ppm or more; Comparative Examples 2-2 to 3 in which filtration is performed using a filter with a pore size of 5 μm or more and the amount of independent particles larger than 5 μm reaches 100 ppm or more; and spherical silica powder of Comparative Examples 2-4 to 5 in which commercially available products are used and the amount of independent particles larger than 5 μm reaches 100 ppm or more have poor slit permeability.

Claims

1. A silicon dioxide powder, which is a silicon dioxide powder formed of spherical silicon dioxide particles, characterized in that: The volume-based cumulative 50% particle size D of the dispersion liquid after the silicon dioxide powder is dispersed by the following dispersion method A is measured by laser diffraction scattering method: 50 The volume-based cumulative 100% particle size is D 100 Less than 5μm, The amount of particles with a particle size exceeding 5 μm detected by a dynamic image analysis method in the dispersion liquid of the silicon dioxide powder after dispersion by the following dispersion method B is 100 ppm or more, and the amount of independent particles with a particle size exceeding 5 μm is less than 100 ppm, Dispersion method A: A method of dispersing a 5 mass % silica powder suspension in ethanol for 5 minutes using an ultrasonic homogenizer with a frequency of 20 kHz; Dispersion method B: A method in which a 0.1 mass % aqueous suspension of silica powder is dispersed for 30 minutes using an ultrasonic cleaner at a frequency of 40 kHz.

2. The silicon dioxide powder according to claim 1, characterized in that The spherical silica particles are surface treated with a silane coupling agent, and the amount of the silane coupling agent is 2.0 to 22.0 particles / nm. 2 .

3. The silicon dioxide powder according to claim 1 or 2, characterized in that The volume-based cumulative 50% particle size D obtained by laser diffraction scattering method 50 (μm) and the volume-based cumulative 100% particle size, i.e. D 100 (μm) ratio, that is, D 100 / D 50 It is 1 or more and 5 or less.

4. The silicon dioxide powder according to claim 1 or 2, characterized in that The volume-based cumulative 50% particle size D obtained by the laser diffraction scattering method 50 and the volume-based cumulative 90% particle size, i.e. D 90 The amount of coarse particles of the silicon dioxide powder calculated by formula (1) is V 90 is greater than 10 and less than 100, V 90 ={(D 90 -D 50 ) / D 50 }×100 (1)。 5. A resin composition, characterized in that The resin composition is formed by dispersing the silica powder according to claim 1 or 2 in a resin.

6. A dispersion, characterized in that The dispersion is formed by dispersing the silicon dioxide powder according to claim 1 or 2 in a solvent.

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