Silica powder, resin composition, and dispersion

Abstract

The present invention relates to a silica powder which, when used as a resin filler material for semiconductor encapsulating materials and the like, enables a resin composition resin to be obtained which has excellent filling properties and slit permeability, and which enables the filler to be adjusted while obtaining a sufficient filling amount. The silica powder of the present invention is characterized in that the volume-based cumulative 50% particle diameter, i.e. D50, measured by a laser diffraction scattering method is 0.05 to 2.00 μm, and the amount of individual particles of 5 μm or more, detected by a dynamic image analysis method, is less than 100 ppm. 50 0.05 to 2.00 μm, and the amount of individual particles of 5 μm or more, detected by a dynamic image analysis method, is less than 100 ppm.

Description

Technical Field

[0001] This invention relates to silica powder, resin compositions, and dispersions suitable for use as filler materials in semiconductor packaging materials, liquid crystal sealants, and thin films. Background Technology

[0002] In recent years, with the development of high performance, miniaturization, and lightweight electronic devices, the semiconductor packaging methods they employ have also been continuously advancing towards higher integration, higher density, and thinner profiles. To make these semiconductor packages practical, in addition to the design of integrated circuits, developing packaging materials suitable for these designs has become crucial.

[0003] For example, epoxy resin is commonly used as an underfill between a semiconductor chip and a wiring substrate. However, epoxy resin, the semiconductor chip, and the wiring substrate each have different coefficients of linear expansion. Therefore, if the connection cannot absorb stress, cracks may form at that connection. To suppress the formation of these cracks, fillers with low coefficients of linear expansion, such as silica, are typically dispersed in the underfill. In this case, to suppress the coefficient of linear expansion of the encapsulation material, the amount of low-expansion-rate filler needs to be increased. Furthermore, when the underfill with added filler is penetrated into the gap, voids must be avoided; that is, the underfill needs to have sufficient slit penetration.

[0004] To increase the filling amount of the aforementioned filler, a hydrophilic dry silica powder with excellent dispersibility, small particle size, and narrow particle size distribution during dispersion has been proposed (Patent Document 1). However, the silica powder described in Patent Document 1, due to its small particle size, although it does not create voids when penetrating into gaps, causes a thickening effect on the resin composition, leading to an increase in the viscosity of the resin composition filled with this silica powder. Therefore, the problem of insufficient filling amount still exists.

[0005] Furthermore, a method has been proposed to improve the affinity with resin by treating the surface of silica particles with high particle size uniformity using a silane coupling agent (e.g., Patent Document 2). The silica particles described in Patent Document 2 indicate that when conventional silica particles are surface-treated with an epoxy silane coupling agent, the silica particles self-aggregate after drying. Further surface treatment with a nitrogen-containing compound can suppress this self-aggregation, thereby inhibiting viscosity increases when filled into the resin. Furthermore, it is shown that by suppressing agglomeration, grading is unnecessary. However, although the number of agglomerated particles is reduced, coarse material, defined as the content of large particles that cannot pass through a 20 μm mesh, still remains at more than 0.1%. When used as a filler in encapsulation materials, this can create voids during gap penetration, still leading to molding defects.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2014-152048

[0009] Patent Document 2: Japanese Patent Application Publication No. 2019-189509 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] Therefore, the object of the present invention is to provide a silica powder with excellent slit permeability. More specifically, the object of the present invention is to provide a silica powder that can be formulated with added fillers while obtaining a sufficient filling amount, thereby obtaining a resin composition resin with excellent filling properties and slit permeability.

[0012] Problem-solving methods

[0013] To address the aforementioned problems, the inventors conducted in-depth research and discovered that even silica powder containing large-diameter particles (agglomerated particles and individual particles) possesses a specific particle size distribution. Furthermore, silica powder with fewer large-diameter individual particles exhibits excellent filling characteristics and slot permeability when mixed with resin and used as filler. The resulting resin composition also demonstrates high flowability and good controllability in its powder state. In this invention, individual particles refer to primary particles.

[0014] That is, the silica powder of the present invention is silica powder formed from spherical silica particles, and the cumulative 50% particle size of the dispersion after dispersion by the following dispersion method A, measured by laser diffraction scattering method, is D. 50The particle size ranges from 0.05 to 2.00 μm, and the cumulative 100% particle size on a volume basis, i.e., D... 100 For particles smaller than 5 μm, the dispersion obtained by the following dispersion method B has a particle size greater than 100 ppm of particles larger than 5 μm detected by dynamic image analysis, and the number of independent particles is less than 100 ppm.

[0015] [Dispersion Method A] A method for dispersing an ethanol suspension of 5% by mass silica powder for 5 minutes using an ultrasonic homogenizer with a frequency of 20 kHz.

[0016] [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.

[0017] In the silica powder of the present invention, preferably 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 .

[0018] Furthermore, the volume-based cumulative 50% particle size, i.e., D, obtained using laser diffraction scattering, is... 50 (μm) and the cumulative 100% particle size based on the volumetric standard, i.e., D 100 The ratio of (μm) to (D) 100 / D 50 Preferably, the particle size is 1 or more and 5 or less, and the cumulative 50% particle size based on the volume reference obtained by laser diffraction scattering method is D. 50 and the cumulative 90% volumetric particle size D based on volumetric reference 90 The amount of coarse particles (V) of the spherical silica particles was calculated using formula (1). 90 The value is preferably 10 or more but less than 100.

[0019] V 90 ={(D 90 -D 50 ) / D 50}×100 (1)

[0020] Invention Effects

[0021] The silica powder of the present invention has good controllability because it contains a specific amount of particles with a particle size exceeding 5 μm detected after dispersion by dispersion method B; the cumulative 50% particle size based on the volume standard measured by dispersion method A, i.e., D... 50 Within a specific particle size range, the cumulative 100% particle size on a volume basis, i.e., D 100The silica powder has a particle size smaller than a specific value; furthermore, after dispersion using method B, the number of individual particles with a diameter exceeding 5 μm is reduced (individual particles are less than a specific amount). Therefore, the resin composition containing this silica powder can simultaneously possess excellent filling properties and slit penetration. Thus, it is suitable as a filler material for semiconductor packaging materials and semiconductor mounting adhesives. It is particularly suitable as a filler for high-density packaging resins.

[0022] Silica powder contains both individual particles and aggregated particles. If a resin composition containing added silica powder and after mixing contains a large number of large-diameter individual particles and aggregated particles (hereinafter also referred to as large-diameter particles), then when the resin composition is used as a semiconductor packaging material or a filler material for semiconductor mounting adhesives, the penetration of the resin composition during the gap penetration process will be hindered by the large particles, easily leading to poor gap penetration.

[0023] 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 dispersion by weak shear dispersion method B, the resin composition using the silica powder of the present invention still exhibits excellent slit permeability. This is because the cumulative 100% particle size on a volume basis, i.e., D, obtained by dispersion by strong shear dispersion method A, is... 100 The number of individual particles smaller than a specific particle size, and whose particle size exceeds 5 μm after dispersion by dispersion method B, is less than a specific quantity. This is presumably because, in its unsheared state before being added to the resin for mixing, the silica powder of the present invention contains both agglomerated particles and individual particles. However, in the resin composition after mixing with the resin and undergoing shearing, the agglomerated particles are dispersed into smaller particles due to strong shearing. On the other hand, the particle size of the individual particles exceeding 5 μm detected after dispersion by dispersion method B does not change due to strong shearing, but in the silica powder of the present invention, their content has been reduced to below a specific quantity, thus not affecting slit permeability. Detailed Implementation

[0024] The silica powder of the present invention will be described in detail below with reference to the embodiments.

[0025] [Silica powder]

[0026] The silica powder of the present invention is formed from spherical silica particles. The dispersion of the silica powder after dispersion by the following dispersion method A is measured by laser diffraction scattering method, with the cumulative 50% particle size as the volume reference, i.e., D. 50 The particle size ranges from 0.05 to 2.00 μm, and the cumulative 100% particle size on a volume basis, i.e., D... 100 It is below 5μm.

[0027] [Dispersion Method A] A method for dispersing an ethanol suspension of 5% by mass silica powder for 5 minutes using an ultrasonic homogenizer with a frequency of 20 kHz.

[0028] Because dispersion method A uses a low-frequency ultrasonic homogenizer to apply strong shear, the measurement results obtained by laser diffraction scattering method A reflect the state of the silica powder during the mixing process when it is filled into the resin. The D… of the silica powder dispersion treated by dispersion method A is measured. 100 As can be seen, no large particles were detected in the particle size distribution, indicating that the particles can be dispersed under strong shear. However, due to the low sensitivity of laser diffraction scattering method at the percentage level, it cannot detect trace particles with a diameter exceeding D in silica powder. 100 The particles were detected and quantified.

[0029] Among them, the cumulative 50% particle size based on volume is D 50 The particle size is 0.05–2.00 μm. When it is less than 0.05 μm, it induces a thickening effect on the resin composition, leading to an increase in the viscosity of the resin composition filled with this powder. Therefore, there is a tendency to not obtain sufficient filling amount. When it exceeds 2.00 μm, when the resin composition filled with this powder is subjected to crevice penetration, the penetration is hindered due to the narrowness of the crevice and the small particle size difference, and there is a tendency to easily generate voids. If D 50 Within the range of 0.05 to 2.00 μm, even with a large amount of silica powder added to the resin, the low viscosity of the resin composition can be maintained.

[0030] Furthermore, the cumulative 100% particle size on a volume basis, i.e., D, of the silica powder dispersion dispersed by dispersion method A was measured by laser diffraction scattering. 100 The size should be below 5μm, preferably less than 3μm.

[0031] Wherein, if the volumetric reference cumulative 100% of the particle size, i.e., D 100 If the particle size exceeds 5μm, the presence of particles will hinder the penetration of the gaps and create voids, leading to molding defects. If D 100 If the particle size is less than 5 μm, and the amount of independent particles larger than 5 μm, as measured by the method described later, is less than 100 ppm, then even with the addition of a large amount of silica powder to the resin, good slit permeability can be exhibited when the resin composition penetrates into the crevices. (Volume-based cumulative D) 100 Preferably, it is below 3μm.

[0032] Furthermore, the silica powder of the present invention, when dispersed by the following dispersion method B, has a dispersion of more than 100 ppm of particles with a diameter greater than 5 μm, as detected by dynamic image analysis, and a dispersion of less than 100 ppm of individual particles with a diameter greater than 5 μm.

[0033] [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.

[0034] As described above, in addition to measuring the particle size distribution of the dispersion using dispersion method A (which applies strong shear) using laser diffraction scattering, the amount of particles larger than 5 μm and the amount of independent particles larger than 5 μm were measured using dynamic image analysis for the dispersion using dispersion method B. Because dispersion method B uses a high-frequency ultrasonic cleaner to apply weak shear, the particles larger than 5 μm detected by dynamic image analysis include aggregated particles that disperse into smaller particles after strong shearing, as well as independent particles that cannot be dispersed even with strong shearing. Independent particles larger than 5 μm refer to particles that cannot be dispersed even with strong shearing. Furthermore, to distinguish and detect these aggregated particles and independent particles, the image was filtered using parameters representing shape. In the "roundness" calculated in dynamic image analysis, particles with a roundness of 0.90 or higher were considered to have high roundness and were identified as independent spherical particles; while particles with a roundness of less than 0.90 were identified as amorphous and were more likely to be aggregated particles formed from primary particle aggregation.

[0035] The amount of silica powder particles with a diameter greater than 5 μm, detected by dynamic image analysis, is 100 ppm or more. As mentioned above, the particles detected here include both aggregated particles formed by primary particle aggregation and individual particles. If this particle amount is 100 ppm or more, the flowability of the silica powder can be improved, thereby improving the controllability when adding silica powder to the resin.

[0036] On the other hand, the amount of individual particles with a particle size greater than 5 μm is less than 100 ppm. Preferably less than 50 ppm, more preferably less than 10 ppm. If the amount of individual particles with a particle size greater than 5 μm is more than 100 ppm, the individual particles may not be able to penetrate into the gaps, thus creating voids and causing molding defects. If it is less than 100 ppm, even with the addition of a large number of spherical silica particles to the resin, good slit permeability can be exhibited when the resin composition penetrates into the gaps.

[0037] That is, when the dispersion obtained by dispersion method B has a particle size greater than 5 μm of more than 100 ppm and an individual particle size greater than 5 μm of less than 100 ppm as detected by dynamic image analysis, the silica powder of the present invention before shearing has a particle size greater than 100 ppm of both aggregated particles and individual particles greater than 5 μm of more than 100 ppm. Therefore, it has high fluidity and good controllability when adding silica powder to resin. After strong shearing is applied to disperse silica powder in resin, the aggregated particles with a particle size greater than 5 μm are dispersed due to strong shearing, and the individual particles with a particle size greater than 5 μm remain in a state of less than 100 ppm. Even if a large number of spherical silica particles are added to the resin, it can still exhibit good slit permeability when the resin composition penetrates into the gaps. Furthermore, when the dispersion obtained by dispersion method B has a particle size exceeding 3 μm of more than 100 ppm and an individual particle size exceeding 3 μm of less than 100 ppm as detected by dynamic image analysis, the silica powder of the present invention before shearing has both aggregated particles exceeding 3 μm and individual particles exceeding 3 μm of more than 100 ppm, thus exhibiting high fluidity and good controllability when adding silica powder to resin. After being dispersed into the resin under strong shearing, the aggregated particles exceeding 3 μm of more than 3 μm are dispersed due to strong shearing, while the individual particles exceeding 3 μm of more than 3 μm remain at less than 100 ppm. Even when a large number of spherical silica particles are added to the resin, the time required for the resin composition to penetrate into the gaps can be shortened, exhibiting good slit permeability.

[0038] Furthermore, the silica powder particles with a diameter of less than 5 μm, detected by dynamic image analysis, preferably have a sphericity of 0.90 or higher. A sphericity of 0.90 or higher increases the proportion of spherical particles, improves flowability, and thus exhibits good slit permeability.

[0039] For silica powder particles with a diameter of less than 5 μm detected by dynamic image analysis, the aspect ratio (vertical-to-horizontal ratio) is preferably 0.92 or higher. An aspect ratio of 0.92 or higher increases the proportion of spherical particles, improves flowability, and exhibits good slit permeability.

[0040] In this invention, spherical silica particles can be surface-treated with a silane coupling agent. The preferred concentration of the silane coupling agent is 2.0–22.0 particles / nm. 2 More preferably, it is 4.0–18.0 per nm. 2 When the concentration of the silane coupling agent is between 2.0 and 22.0 units / nm... 2 At this time, it can effectively block the contact between the reactive hydroxyl groups on the surface of silica particles and the resin. When the composition is 2.0 particles / nm2 At the above levels, the reactive hydroxyl groups on the surface of silica particles are blocked by organic resin, leading to a trend of increased affinity; while at 22.0 hydroxyl groups / nm... 2 In the following cases, there is less excess silane coupling agent, and the dispersibility of silica particles tends to improve.

[0041] The particle size distribution of silica powder can be obtained by using the cumulative 50% volume diameter of the volume-based particle size distribution, i.e., D, obtained by laser diffraction scattering. 50 and D as the largest particle size 100 Their ratio (D) 100 / D 50 (D) 100 / D 50 The preferred value is 1 or more and 5 or less. If D 100 / D 50 If the value is above 1 and below 5, the spherical silica particles can easily fill the resin in a near-close-packed form. Even if a large amount of spherical silica particles are filled, the amount of resin not included in the particle gaps will increase, thereby maintaining the low viscosity of the resin composition.

[0042] Furthermore, the amount of coarse particles in the silica powder can be calculated using the following formula (1): V 90 To express.

[0043] V 90 ={(D 90 -D 50 ) / D 50}×100 (1)

[0044] D 50 Cumulative 50% volume diameter of volume-based particle size distribution obtained by laser diffraction scattering method

[0045] D 90 Cumulative 90% volume percentage particle size of volume-based particle size distribution obtained by laser diffraction scattering method

[0046] V 90 Preferably, the value is 10 or more but less than 100, more preferably 10 to 95, and even more preferably 20 to 90. When V 90 When the value is 10 or higher but less than 100, good crevice permeability can be obtained when the resin composition penetrates into the crevice.

[0047] [use]

[0048] The applications of the silica powder of the present invention are not particularly limited. For example, it can be used as a filler in semiconductor packaging materials or semiconductor mounting adhesives, a filler in chip mounting films or chip mounting pastes, or as a filler in resin compositions such as insulating films for semiconductor packaging substrates. In particular, the spherical silica particles obtained in the present invention are suitable for use as fillers in high-density packaging resin compositions.

[0049] Furthermore, the silica powder of the present invention can also be used as abrasive grains in CMP (Chemical Mechanical Polishing) abrasives, abrasive grains in grinding wheels, external additives in toners, additives in liquid crystal sealing materials, dental filling materials, or as inkjet coating materials.

[0050] [Method for manufacturing silica powder]

[0051] Next, the method for manufacturing the silica powder of the present invention will be described.

[0052] The silica-based spherical particles are classified to obtain silica powder composed of spherical silica particles. This is explained in detail below.

[0053] <Silica-based spherical particles>

[0054] The silica-based spherical particles used in this invention are preferably silica-based spherical particles with an average particle size of 0.05 to 2.00 μm as measured by laser diffraction scattering.

[0055] In addition, wet silica-based spherical particles can also be obtained using the sol-gel method to produce a dispersion of these particles. The sol-gel method involves hydrolyzing and condensing silanols in a reaction medium composed of water containing a catalyst and an organic solvent to generate a silica sol, which is then gelled to obtain the wet silica-based spherical particle dispersion.

[0056] Furthermore, dry-process silica spherical particles can also be obtained using a flame method. The flame method involves generating silica spherical particles by burning silicon compounds, allowing them to grow and coalesce in and near a flame. For example, International Publication No. 2020 / 175160 discloses a method for preparing silica by burning silicon compounds, using a burner with a concentric multi-tube structure of three or more tubes, surrounded by a reactor with a cooling jacket. By adjusting the combustion and cooling conditions, silica powder with a cumulative 50% mass particle size of 300 nm or more and 500 nm or less in the mass-based particle size distribution obtained by centrifugal sedimentation can be obtained.

[0057] <Hierarchical Processing>

[0058] By classifying silica-based spherical particles, spherical silica particles with fewer independent particles can be obtained. For example, the wet-process silica-based spherical particle dispersion can be wet-filtered to remove the independent particles it contains. That is, by filtering the wet-process silica-based spherical particle dispersion, independent particles can be separated from the filter media along with reaction residues, and any agglomerated particles or clumps that are formed can also be separated. As the filter media, filter media with a pore size of 5 μm or less can be used without particular restriction in wet filtration, but filter media with a pore size of 3 μm or less are preferred. If the pore size is too small, not only will the filtration efficiency decrease, but the average particle size of the filtered silica particles will also deviate significantly from the above range; therefore, the lower limit of the pore size is usually 1 μm, depending on the average particle size of the desired powder. The material of the filter membrane is not particularly limited; for example, it can be made of resin (polypropylene, PTFE, etc.) or metal. From the perspective of preventing the introduction of metal impurities, resin-made filter membranes are preferred.

[0059] Furthermore, since the dry-process silica spherical particles are prepared as powder, they can also be dispersed in a solvent and subjected to wet filtration. In this case, the solvent is not particularly limited, but a solvent in which the dry-process silica particles are easily dispersed is preferred.

[0060] Alternatively, classification processes utilizing inertial forces, such as liquid cyclones or wind-based classification, can be used. The medium is not particularly limited, but from the viewpoint of good dispersibility in the medium, liquids are preferred for wet-process silica-based spherical particles, and air is preferred for dry-process silica-based spherical particles.

[0061] <Separation Processing>

[0062] In this embodiment, the spherical silica particles obtained through grading can be subjected to solid-liquid separation if necessary, and recovered as a filter cake. Alternatively, solid-liquid separation can be performed after adding a coagulant to form weak aggregates. Adding a coagulant facilitates solid-liquid separation and recovery. The filtration method is not particularly limited; for example, known methods such as vacuum filtration, pressure filtration, and centrifugal filtration can be used.

[0063] Furthermore, there are no particular restrictions on the coagulant added, but from the perspective of preventing contamination into the resulting spherical silica particles, it is preferable to use compounds that do not contain metal elements as coagulants, such as carbon dioxide, ammonium carbonate, ammonium bicarbonate, and ammonium carbamate.

[0064] <Drying process>

[0065] In this embodiment, the filter cake containing spherical silica particles obtained through separation processing can be dried if necessary to obtain silica powder composed of spherical silica particles.

[0066] The drying method is not particularly limited and well-known methods such as forced-air drying and vacuum drying can be used. However, since drying under reduced pressure makes the material more prone to breakage than drying under atmospheric pressure, vacuum drying is preferred.

[0067] Furthermore, the drying temperature is preferably 35–200°C, more preferably 50–200°C, particularly preferably 80–200°C, and especially preferably 120–200°C. A drying temperature of 35–200°C is advantageous for obtaining easily breakable silica powder.

[0068] <Roasting Treatment>

[0069] In this embodiment, if necessary, the silica powder containing spherical silica particles obtained by drying can be calcined.

[0070] The dried silica powder containing spherical silica particles still contains residual silanol groups, particularly in silica particles made using wet-process silica, where the dispersion medium adsorbed within the particles has not been completely removed. Porosity is also present. To achieve a high degree of removal of the dispersion medium and eliminate silanol groups to obtain dense silica, a further calcination process is preferable, depending on the application. That is, this calcination process is preferred because it reduces the amount of silanol groups on the particle surface and removes the residual dispersion medium within the particles. Residual solvent in the particles, when used as a filler in resins, can generate bubbles upon heating, leading to a decrease in yield. This is especially noticeable in applications requiring high filler concentrations, such as semiconductor packaging materials and liquid crystal sealants. Therefore, this process is particularly preferred in the manufacture of silica particles used in semiconductor packaging materials and liquid crystal sealants.

[0071] The calcination temperature described above is crucial; too low a temperature will make it difficult to remove the dispersion medium, while too high a temperature will cause the silica particles to melt and agglomerate. Therefore, a temperature of 300–1300°C is preferred, and 600–1200°C is even more suitable. The calcination time is not particularly limited as long as the residual dispersion medium is removed, but excessively long times will reduce production efficiency. Therefore, after reaching the target calcination temperature, calcination should be maintained for 0.5–48 hours, and more preferably 2–24 hours. The atmosphere during calcination is also not particularly limited; it can be carried out under inert gases such as argon or nitrogen, or in an atmospheric environment.

[0072] The silica powder of the present invention can be further crushed by known crushing methods to reduce agglomerates before use. The crushing method is not particularly limited; for example, known methods such as ball mills and air jet mills can be used.

[0073] Surface treatment based on silane coupling agents

[0074] Spherical silica particles can be surface-treated using silane coupling agents. Details are as follows.

[0075] <Silane Coupling Agent>

[0076] Examples of silane coupling agents include compounds as shown in formula (2).

[0077] R n –Si–X (4–n) (2)

[0078] In formula (2) above, R is an organic group with 1 to 18 carbon atoms, X is a hydrolyzable group, and n is an integer from 1 to 3.

[0079] Furthermore, examples of X include alkoxy atoms with 1 to 3 carbon atoms such as methoxy, ethoxy, and propoxy, and halogen atoms such as chlorine atoms, with methoxy and / or ethoxy being preferred. It should be noted that when n is 1 or 2, multiple Xs may be the same or different, but are preferably the same. Additionally, n is an integer from 1 to 3, preferably 1 or 2, and particularly preferably 1.

[0080] As examples of silane coupling agents mentioned in formula (2) above, the following can be listed:

[0081] Methyltrimethoxysilane, methyltriethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-acryloyloxytrimethoxysilane, 3-glycidyletheroxypropyltrimethoxysilane, 3-glycidyletheroxypropyltrimethoxysilane Ethoxysilane, 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.

[0082] <Surface treatment agents (other additives)>

[0083] In addition to the silane coupling agent, at least one surface treatment agent selected from silicone oil, siloxanes, and / or silazanes can be added. The surface treatment agent can be added simultaneously with the silane coupling agent, or it can be added after the surface treatment agent. Furthermore, the surface treatment agent can be added after the silane coupling agent. Thus, spherical silica particles with various surface properties can be obtained. For example, spherical silica particles composed of trimethylsilyl and epoxy groups can be readily obtained.

[0084] Regarding the amount of surface treatment agent used, if it is silicone oil, it is preferably added at 0.05 to 80 parts by weight per part by weight of spherical silica particles, more preferably 0.1 to 60 parts by weight, and most preferably 1 to 20 parts by weight. Similarly, if it is a siloxane, it is preferably added at 0.001 to 40 parts by weight per part by weight of spherical silica particles, more preferably 0.003 to 30 parts by weight, and most preferably 0.005 to 20 parts by weight. Similarly, if it is a silazane, it is preferably added at 0.001 to 40 parts by weight per part by weight of silica powder, more preferably 0.003 to 30 parts by weight, and most preferably 0.005 to 20 parts by weight.

[0085] <Mix>

[0086] Spherical silica particles and silane coupling agents are mixed using conventionally known methods. For example, spherical silica particles are placed in a mixing container, and while the particles are fluidized by shaking or stirring, a predetermined amount of silane coupling agent is added by dropping or spraying. Alternatively, silica powder is added to 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 adjusted appropriately based on the amount added.

[0087] After adding the silane coupling agent, it is preferable to continue stirring for at least 10 minutes. Continued stirring allows the silane coupling agent to adhere evenly to the surface of the spherical silica particles.

[0088] As a mixing container, for example, a Henschel-type mixing device equipped with stirring blades or mixing blades, a Radig mixer, an airflow mixer that mixes by airflow, a V-type mixer that mixes by rotating or shaking the container body, a double-cone mixing device, and a rocking mixer can be used.

[0089] <Heat Treatment>

[0090] Through heat treatment, a portion of the added silane coupling agent reacts with the surface of the silica particles (i.e., chemical bonding), while the remaining silane coupling agent does not chemically bond and remains on the surface of the silica particles (i.e., physical adsorption). If the heat treatment temperature is too low, the reaction process is slow, leading to decreased production efficiency; if it is too high, it will promote the decomposition of the silane coupling agent and surface treatment agent, or promote the formation of aggregates due to rapid polymerization. Therefore, although it depends on the silane coupling agent used, the reaction is usually carried out at a temperature of 25–300°C, preferably 40–250°C.

[0091] The heat treatment time can be appropriately determined based on the reactivity of the silane coupling agent used. Generally, a sufficient reaction rate can be obtained within 1 hour to 500 hours. Furthermore, if the heat treatment can be carried out in a mixing vessel, the mixed powder can be directly used in the heat treatment apparatus.

[0092] <Drying>

[0093] There are no particular limitations on the drying temperature, but excessively high temperatures will cause the unbonded silane coupling agent components (physical adsorption) to volatilize and be removed from the spherical silica particles, which is therefore undesirable; excessively low temperatures will not sufficiently remove byproducts. Therefore, the drying temperature is preferably 25–200°C, more preferably 25–180°C, and even more preferably 25–150°C. Drying at temperatures above 25°C can sufficiently remove byproducts generated when the silane coupling agent reacts with the surface of the silica particles.

[0094] There are no particular restrictions on the equipment used for drying; existing and known drying equipment can be used. Furthermore, if drying can be performed within the reaction vessel used during heat treatment, the treated powder can be dried directly within the apparatus.

[0095] The pressure inside the drying apparatus is preferably above atmospheric pressure. Specifically, it is preferably above 1000 hPa. By drying at a pressure above atmospheric pressure, unreacted silane coupling agent can be sufficiently removed. If the pressure is above 1000 hPa, byproducts can be sufficiently removed without causing the physically adsorbed silane coupling agent components to volatilize.

[0096] There are no particular restrictions on drying time; it can be selected appropriately based on the drying conditions, such as drying temperature and pressure. Generally, surface-treated silica powder with byproducts removed can be obtained in about 1 to 48 hours.

[0097] [Dispersion]

[0098] The silica powder of the present invention can be dispersed in a solvent to form a dispersion. There are no particular limitations on the solvent used to disperse the silica powder, as long as it is a solvent capable of easily dispersing the silica powder.

[0099] Solvents that can be used include water and organic solvents such as alcohols, ethers, and ketones. Examples of alcohols include methanol, ethanol, and 2-propanol. Mixtures of water and one or more of the aforementioned organic solvents can also be used as solvents. Furthermore, to improve the stability and dispersibility of the silica powder, various additives such as surfactants, dispersants, thickeners, wetting agents, defoamers, or acidic or alkaline pH adjusters can be added. Moreover, there are no limitations on the pH of the dispersion.

[0100] Applications of dispersions include filling in semiconductor packaging materials and semiconductor mounting adhesives. A dispersion, which is silica powder pre-dispersed in a solvent, can be easily dispersed in resins. For example, by mixing the resin with the dispersion and then removing the solvent, a well-dispersed underfill can be easily prepared.

[0101] [Resin Composition]

[0102] There are no particular limitations on the type of resin used to formulate the silica powder for manufacturing the resin composition of the present invention. The type of resin may be appropriately selected according to the desired application, for example, epoxy resin, acrylic resin, silicone resin, olefin resin, polyimide resin and / or polyester resin, etc.

[0103] The resin composition can be manufactured by means of a known method, which involves mixing silica powder with various resins and other components as necessary.

[0104] When the dispersion of the present invention is mixed with a resin, a resin composition in which the silica powder is better dispersed in the resin can be obtained compared to mixing dried silica powder with the resin. Good dispersion of the silica powder means fewer aggregated particles in the resin composition. Therefore, the viscosity characteristics and slit permeability of the resin composition containing the silica powder of the present invention as a filler material can be further improved.

[0105] The resin composition has applications including semiconductor packaging materials and semiconductor mounting adhesives. The resin composition formulated with silica powder can suppress the coefficient of linear expansion and is suitable for such applications.

[0106] [Summarize]

[0107] 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 silica powder composed of spherical silica particles, and the dispersion after dispersion by the following dispersion method A has a cumulative 50% particle size D measured by laser diffraction scattering method. 50 The particle size ranges from 0.05 to 2.00 μm, and the cumulative 100% particle size D on a volume basis is... 100 The particle size is less than 5 μm; and the dispersion after dispersion method B has a particle size greater than 100 ppm and an individual particle size greater than 5 μm less than 100 ppm as detected by dynamic image analysis.

[0108] [Dispersion Method A] A method for dispersing an ethanol suspension of 5% by mass silica powder for 5 minutes using an ultrasonic homogenizer with a frequency of 20 kHz.

[0109] [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.

[0110] Based on this silica powder, a high filling capacity can be obtained when it is added to the resin, while it does not hinder the penetration of the resin composition when penetrating into crevices, thus possessing both excellent filling properties and crevices permeability.

[0111] The silica powder of the second aspect of the present invention is characterized in that, in the silica powder of the first aspect described above, 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 .

[0112] The silica powder of the third aspect of the present invention is characterized in that: it is a silica powder of the first or second aspect described above, wherein the cumulative 50% particle size based on the volume reference, i.e., D, is measured by laser diffraction scattering method. 50 (μm) and the cumulative 100% particle size based on the volumetric standard, i.e., D 100 The ratio of (μm) to (D) 100 / D 50 () is 1 or more and 5 or less.

[0113] The silica powder according to the fourth aspect of the present invention is characterized in that: it comprises silica powder according to the first or second aspect described above, wherein the cumulative 50% particle size, i.e., D, is determined by laser diffraction scattering. 50 And the cumulative 90% particle size based on volume is D 90 The amount (V) of coarse particles in the silica powder obtained using formula (1) 90 The value is 10 or higher and less than 100.

[0114] V 90 ={(D 90 -D 50 ) / D 50}×100 (1)

[0115] The resin composition according to the fifth aspect of the present invention is formed by dispersing the silica powder according to the first or second aspect in a resin.

[0116] The dispersion according to the sixth aspect of the present invention is formed by dispersing the silica powder according to the first or second aspect in a solvent.

[0117] Example

[0118] The following are specific examples of embodiments described in this implementation, but the present invention is not limited to these embodiments in any way.

[0119] The methods for measuring and evaluating the various properties of silica powder are as follows.

[0120] (Volume-based particle size distribution using laser diffraction scattering method)

[0121] Weigh approximately 0.5 g of silica powder into a 50 mL glass bottle, add 10 g of ethanol, and disperse using an ultrasonic homogenizer (Sonifier 250, Branson, Inc.) at a frequency of 20 kHz for 5 minutes. Then, measure the volumetric cumulative 50% particle size (D) of the spherical silica particles using a laser diffraction scattering particle size distribution measurement device (LS 13 320, Beckman Coulter, Inc.). 50 (μm), the cumulative 100% particle size based on volume is D 100 (μm), and the cumulative 90% volume percentage particle size on a volume basis, i.e., D 90 (μm). Based on the obtained D 50 and D 90 The amount of coarse particles (V) of the surface-treated silica powder can be determined using equation (1). 90 ).

[0122] V 90 ={(D 90 -D 50 ) / D 50}×100 (1)

[0123] (Dynamic Image Analysis Method)

[0124] (A method for measuring roundness, aspect ratio, particle size exceeding 5 μm, and the number of independent particles exceeding 5 μm using dynamic image analysis)

[0125] (1) The dynamic image analysis method used a dispersion in pure water to disperse silica powder. 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 form a suspension of 0.1% by mass, and then dispersing it for 30 minutes using an ultrasonic cleaner with a frequency of 40 kHz.

[0126] (2) The dispersion prepared in (1) was 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. The "equivalent particle diameter d", "roundness" and "aspect ratio" were obtained from the obtained particle images through internal calculations of the device.

[0127] (3) When calculating the number of particles with a diameter greater than 5 μm and the number of independent particles with a diameter greater than 5 μm from the particle image obtained in (2), only particles with an "equivalent circular diameter dd > 5 μm" are selected, and the number of particles with a diameter greater than 5 μm is measured. Further, particles with a diameter greater than 5 μm are identified by "roundness ≥ 0.9" and "aspect ratio ≥ 0.92", and the number of independent particles with a diameter greater than 5 μm is measured. Among them, the equivalent circular diameter d [μm] of the particles is used, and the particle quantity W [ppm] of particles with a diameter greater than 5 μm and independent particles with a diameter greater than 5 μm are calculated according to the calculation method in (4) below. When calculating the number of particles with a diameter greater than 3 μm and the number of independent particles with a diameter greater than 3 μm, except that only particles with an "equivalent circular diameter d > 3 μm" are selected from the particle image obtained in (2), the rest is the same as the above method.

[0128] (4) Using the equivalent spherical particle size d [μm] obtained from dynamic image analysis, the mass w [g] of each particle is calculated according to equation (i). The true density ρ of amorphous silica is ρ = 2.2 [g·m³]. -3 The value of ].

[0129] w = ρ × π / 6 × (d ÷ 10) 6 ) 3 (i)

[0130] This operation is performed on each particle detected by dynamic image analysis, and the weight of each particle is calculated. Their sum is taken as the total weight ws[g], and the particle amount W[ppm] in the amount of spherical silica particles used for measurement is obtained according to equation (ii).

[0131] W=ws / (0.015×(0.1 / 100)) (ii)

[0132] Furthermore, the detection limit of this measurement method was calculated by measuring 0.015 mL of a dispersion containing 10 ppm of standard particle 1 (4206A manufactured by Thermo Fisher Scientific) in the dispersion prepared in (1) above. The amount of individual particles obtained by measuring the dispersion containing the added standard particles represents the amount of standard particles to be detected, and the detection limit for particles with a diameter greater than 5 μm was determined to be 10 ppm based on this result. Similarly, a dispersion containing standard particle 2 (4204A manufactured by Thermo Fisher Scientific) was measured, and the detection limit for particles with a diameter greater than 3 μm was determined to be 10 ppm.

[0133] (Method for measuring the amount of silane coupling agent in silica powder)

[0134] Using the carbon content of silica powder (described later), the BET specific surface area of ​​silica powder (described later), and the number of carbon atoms (unitless) of the silane coupling agent, the amount of silane coupling agent (atoms / nm) is calculated according to the following formula. 2 ).

[0135] Silane coupling agent content (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 constant (atoms / mol) / BET specific surface area of ​​silica powder (m²) 2 / g) / 10 18

[0136] (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, when using KBM-403 manufactured by Shin-Etsu Silicone, since this silane coupling agent has the molecular formula C9H...) 20 O5Si, therefore the silane coupling agent has 9 carbon atoms. N is the number of carbon atoms in the hydrolyzable group X of the silane coupling agent multiplied by 2. For example, when X is methoxy, N is 2; when X is ethoxy, N is 4. Avogadro's constant is 6.02 × 10⁻⁶. 23 (units / mol)

[0137] (Carbon content)

[0138] The carbon content (mass %) was measured using a total nitrogen and total carbon measuring device (Sumigraph NC-TR22 manufactured by Sumigraph Chemical Analysis Center). Additionally, the sample amount of silica measured was 50–100 mg.

[0139] (BET specific surface area)

[0140] The BET specific surface area S (m²) was measured using a specific surface area measuring device (SA-1000 manufactured by Shibata Rikan Co., Ltd.) via the nitrogen adsorption BET single-point method. 2 / g).

[0141] (Evaluation of the permeability of silica powder in gaps)

[0142] Add 36g of silica powder to a mixture of 17g of bisphenol F epoxy resin (YDF-8170C manufactured by Nippon Steel Chemical Materials Co., Ltd.) and 7g of amine curing agent (KARAHARD AA manufactured by Nippon Kayaku Co., Ltd.), and stir by hand. Premix the hand-stirred resin composition using a rotary mixer (Awatori Rentaro AR-500 manufactured by THINKY) (mixing: 1000 rpm, 8 minutes; defoaming: 2000 rpm, 2 minutes). Store the premixed resin composition in a 25°C constant temperature water bath, then use a three-roll mill (BR-150HCV manufactured by IMEX, roller diameter...). The silica powder was mixed (63.5%). The mixing conditions were: mixing temperature 25°C, roller distance 20 μm, and 8 mixing cycles. The resulting resin composition was defoamed for 30 minutes under reduced pressure using a vacuum pump (TSW-150, Sato Vacuum Corporation) to obtain a mixed resin composition. This mixed resin composition was dropped into the slit inlet, where two glass plates were stacked to form a 30 μm gap and heated to 110°C, for a high-temperature permeability test. The presence or absence of flow marks was visually evaluated. No flow marks were observed, indicating good slit permeability; the presence of flow marks indicated poor slit permeability. Good slit permeability indicated that the silica powder possessed excellent filling and viscosity characteristics.

[0143] [Example 1-1]

[0144] 4.3 parts by mass of methanol, 1.7 parts by mass of isopropanol, and 1.4 parts by mass of ammonia (25% by mass) were prepared as the reaction medium, and the reaction temperature was set to 40°C and stirred. 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 added to the reaction medium as a raw material to prepare silica seed particles. Next, 100 parts by mass of tetramethoxysilane and 28.5 parts by mass of methanol were added to the reaction medium, along with 42.8 parts by mass of ammonia (25% by mass), to allow the sol-gel silica particles to grow and synthesize. After the addition was complete, 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 silica-based spherical particle dispersion was wet-filtered using a 3 μm pore size polypropylene membrane to remove individual particles. Then, 0.9 parts by mass of dry ice were added, and the mixture was left to stand for 20 hours. After 20 hours, the sol-gel silica particles had settled. Solid-liquid separation was performed using quantitative filter paper (maintaining a particle size of 6 μm) to obtain a filter cake. Then, it was dried under reduced pressure at 100°C for 15 hours. Next, it was calcined at 800°C for 10 hours in air. Finally, it was crushed using an air-jet pulverizer 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.

[0145] [Examples 1-2]

[0146] In wet filtration, except that the pore size of the polypropylene filter was changed from 3 μm to 5 μm, the remaining steps were the same as in Example 1-1 to prepare silica powder 2 and perform measurements. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0147] [Examples 1-3]

[0148] 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 (25% by 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, and silica seed particles were prepared. Afterwards, silica powder 3 was prepared according to the same method as in Example 1-1, and measurements were performed. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0149] [Examples 1-4]

[0150] 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 (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 for 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 (25% by mass). Silica powder 4 was then prepared according to the same method as in Example 1-1, and measurements were performed. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0151] [Examples 1-5]

[0152] 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 (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 (25% by mass) was added to the reaction medium as a raw material to allow the sol-gel silica particles to grow and synthesize. Afterwards, silica powder 5 was prepared according to the same method as in Example 1-1, and measurements were performed. Table 1 shows the morphology and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0153] [Examples 1-6]

[0154] 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 (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. Afterwards, silica powder 6 was prepared according to the same method as in Example 1-1, and measurements were performed. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0155] [Examples 1-7]

[0156] Except for changing the pore size of the polypropylene filter from 3 μm to 5 μm during wet filtration, silica powder 7 was prepared and measured using the same method as in Examples 1-6. Table 1 shows the morphology and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0157] [Examples 1-8]

[0158] Five parts by weight of dry-processed silica spherical particles (Silphill Nss-40D manufactured by Tokuyama Corporation) with an average particle size of 0.38 μm were added to 100 parts by weight of pure water to prepare a dispersion of dry-processed silica spherical particles. The dispersion was wet-filtered using a polypropylene filter with a pore size of 3 μm to remove individual particles, yielding silica particles 8, which were then measured. Table 1 shows the morphology and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0159] [Examples 1-9]

[0160] Except that dry-processed silica spherical particles (Silphill Nss-24D manufactured by Tokuyama Corporation) with an average particle size of 0.24 μm were used instead of dry-processed silica spherical particles (Silphill Nss-40D manufactured by Tokuyama Corporation) with an average particle size of 0.38 μm, silica powder 9 was prepared and measured using the same method as in Examples 1-8. Table 1 shows the morphology and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0161] [Examples 1-10]

[0162] Dry-process silica spherical particles (Silphill Nss-40D manufactured by Tokuyama Corporation) with an average particle size of 0.38 μm were classified using an air classifier to prepare silica powder 10, and measurements were performed. Table 1 shows the morphology and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0163] [Comparative Example 1-1]

[0164] Except for the absence of a 3 μm pore size polypropylene filter for wet filtration, silica powder A was prepared and measured using the same method as in Examples 1-1. Table 1 shows the morphology and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0165] [Comparative Examples 1-2]

[0166] In wet filtration, silica powder B was prepared and measured using the same method as in Examples 1-1, except that the pore size of the polypropylene filter was changed from 3 μm to 7 μm. Table 1 shows the properties and preparation conditions of the silica powder, and Table 2 shows the physical properties of the silica powder.

[0167] [Comparative Examples 1-3]

[0168] In wet filtration, silica powder C was prepared and measured using the same method as in Examples 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.

[0169] [Comparative Examples 1-4] 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.

[0170] [Comparative Examples 1-5]

[0171] 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.

[0172] Table 1

[0173]

[0174] Table 2

[0175]

[0176] [Example 2-1]

[0177] The silica powder 1 prepared in Example 1-1 was added to a mixing container and stirred. Subsequently, for 100 parts by mass of silica powder 1, 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.5 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were supplied via a peristaltic pump (SJ-1211II-H manufactured by ATTA). Stirring continued immediately after supplying the agent, and the mixture was mixed for 15 minutes. After mixing, while continuing stirring, the temperature was raised from room temperature to 40°C over 20 minutes, and then maintained at 40°C for 60 minutes. Then, the temperature was raised to 100°C over 60 minutes and maintained at 100°C for 180 minutes to complete the reaction. After the reaction, the mixture was cooled and dried by purging nitrogen gas into the container while maintaining a temperature of 30°C, yielding spherical silica powder surface-treated with the silane coupling agent. 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.

[0178] [Example 2-2]

[0179] 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.

[0180] [Examples 2-3]

[0181] Except that for 100 parts by weight of silica powder 1, no surface treatment agent was used, and the silane coupling agent was replaced with 0.5 parts by weight of 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 Examples 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.

[0182] [Examples 2-4]

[0183] Except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.7 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 3, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0184] [Examples 2-5]

[0185] Except that 0.02 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.2 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 4, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0186] [Examples 2-6]

[0187] Except that 0.08 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 4.0 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 5, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0188] [Examples 2-7]

[0189] Except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.3 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 6, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0190] [Examples 2-8]

[0191] Except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.3 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 7, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0192] [Examples 2-9]

[0193] Except that 0.03 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.5 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 8, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0194] [Example 2-10]

[0195] Except that 0.05 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 2.5 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 9, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0196] [Example 2-11]

[0197] Except that 0.03 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.5 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 10, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0198] [Example 2-12]

[0199] Except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.2 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 1, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0200] [Example 2-13]

[0201] Except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 1.2 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 1, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0202] [Example 2-14]

[0203] Except that 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 2.4 parts by mass of silane coupling agent (KBM-403 manufactured by Shin-Etsu Quartz Co., Ltd.) were used for 100 parts by mass of silica powder 1, the surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0204] [Comparative Example 2-1]

[0205] Except that silica powder A prepared in Comparative Example 1-1 was used instead of silica powder 1, surface-treated silica powder was prepared and measured using the same method 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.

[0206] [Comparative Example 2-2]

[0207] Except that silica powder B prepared in Comparative Examples 1-2 was used instead of silica powder 1, surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0208] [Comparative Examples 2-3]

[0209] Except that silica powder C prepared in Comparative Examples 1-3 was used instead of silica powder 1, surface-treated silica powder was prepared and measured using the same method as in Examples 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.

[0210] [Comparative Examples 2-4]

[0211] Except that commercially available spherical silica powder D from Comparative Examples 1-4 was used instead of silica powder 1, and for 100 parts by mass of spherical silica powder D, 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.9 parts 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 using the same method as in Examples 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.

[0212] [Comparative Examples 2-5]

[0213] Except that commercially available spherical silica powder D from Comparative Examples 1-4 was used instead of silica powder 1, and for 100 parts by mass of spherical silica powder D, 0.01 parts by mass of hexamethyldisilazane (SZ-31 manufactured by Shin-Etsu Quartz Co., Ltd.) and 0.9 parts 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 using the same method as in Examples 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.

[0214] Table 3

[0215]

[0216] Table 4

[0217]

[0218] The silica powders used in Examples 1-1 to 9, which were filtered using a filter with a pore size of less than 5 μm to remove independent particles larger than 5 μm and control the amount of independent particles larger than 5 μm to less than 100 ppm, and in Examples 1-10, which were classified by a wind classifier to remove independent particles larger than 5 μm and control the amount of independent particles larger than 5 μm to less than 100 ppm, have good pore permeability.

[0219] On the other hand, Comparative Example 1-1, which had no filtration operation and had an independent particle size greater than 5 μm of 100 ppm or more; Comparative Examples 1-2 to 3, which had an independent particle size greater than 5 μm of 100 ppm or more after filtration with a filter with a pore size greater than 5 μm; and Comparative Examples 1-4 to 5, which had commercially available products and had an independent particle size greater than 5 μm of 100 ppm or more, showed poor pore permeability.

[0220] In surface-treated silica powder, regardless of the type of treatment agent, the silica powders of Examples 2-1 to 14, which remove independent particles larger than 5 μm by filtration or air classification with a pore size of less than 5 μm and control the amount of independent particles larger than 5 μm to less than 100 ppm, have good pore permeability.

[0221] On the other hand, Comparative Example 2-1, which had no filtration operation and had an independent particle size greater than 5 μm of 100 ppm or more; Comparative Examples 2-2 to 3, which had an independent particle size greater than 5 μm of 100 ppm or more after filtration with a filter with a pore size greater than 5 μm; and Comparative Examples 2-4 to 5, which had commercially available spherical silica powder with an independent particle size greater than 5 μm of 100 ppm or more, all exhibited poor pore permeability.

Claims

1. A silica powder formed of spherical silica particles, characterized in that, the amount of particles having a particle size of more than 5 μm in a dispersion liquid of the silica powder dispersed by a dispersion method B described below is 100 ppm or more, and the amount of independent particles having a particle size of more than 5 μm is less than 100 ppm, the dispersion method B is a method of dispersing a 0.1 mass% silica powder suspension in water using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes. The volume-based cumulative 50% particle diameter, i.e., D50, of the dispersion liquid of the silica powder dispersed by the following dispersion method A was also measured by a laser diffraction scattering method. 50 0.05 to 2.00 μm, and the volume-based cumulative 100% particle diameter, i.e., D100, was 5 μm or less. 100 0.05 to 2.00 μm, and the volume-based cumulative 100% particle diameter, i.e., D100, was 5 μm or less. Dispersion method A: a method of dispersing a 5 mass% silica powder suspension in ethanol using an ultrasonic homogenizer at a frequency of 20 kHz for 5 minutes. Dispersion method B: a method of dispersing a 0.1 mass% silica powder suspension in water using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes.

2. The silica powder according to claim 1, characterized in that, the amount of particles having a particle size of more than 5 μm in a dispersion liquid of the silica powder dispersed by a dispersion method B described below is 100 ppm or more, and the amount of independent particles having a particle size of more than 5 μm is less than 100 ppm, the dispersion method B is a method of dispersing a 0.1 mass% silica powder suspension in water using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes.

3. The silica powder according to claim 1 or 2, characterized in that, the amount of particles having a particle size of more than 5 μm in a dispersion liquid of the silica powder dispersed by a dispersion method B described below is 100 ppm or more, and the amount of independent particles having a particle size of more than 5 μm is less than 100 ppm, the dispersion method B is a method of dispersing a 0.1 mass% silica powder suspension in water using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes.

4. The silica powder according to claim 1 or 2, characterized in that, the amount of particles having a particle size of more than 5 μm in a dispersion liquid of the silica powder dispersed by a dispersion method B described below is 100 ppm or more, and the amount of independent particles having a particle size of more than 5 μm is less than 100 ppm, the dispersion method B is a method of dispersing a 0.1 mass% silica powder suspension in water using an ultrasonic cleaner at a frequency of 40 kHz for 30 minutes.

5. A resin composition comprising the silica powder according to any one of claims 1 to 4. The spherical silica particles are surface-treated with a silane coupling agent, and the amount of the component of the silane coupling agent is 2.0 to 22.0 per nm 2 .

6. A dispersion formed by dispersing the silica powder according to any one of claims 1 to 4 in a solvent. The volume-based cumulative 50% particle diameter, that is, D50, obtained by the laser diffraction scattering method 50 The ratio of the volume-based cumulative 100% particle diameter, that is, D100, to the volume-based cumulative 50% particle diameter, that is, D50 100 The ratio of the volume-based cumulative 50% particle diameter, that is, D50, to the volume-based cumulative 10% particle diameter, that is, D10 100 / D 50 is 1 or more and 5 or less, where D 50 and D 100 are both in μm. ​ The volume-based cumulative 50% particle diameter, that is, D50, obtained by the laser diffraction scattering method 50 and the volume-based cumulative 90% particle diameter, that is, D90 90 The amount of coarse particles of the silica powder, that is, V, calculated by Formula (1) 90 is 10 or greater but less than 100, V 90 = {(D 90 -D 50 ) / D 50} x 100 (1).

5. A resin composition characterized by comprising: ​ 6. A dispersion, characterized in that, ​

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