WO2024128317A1 - Spherical alumina powder - Google Patents

Spherical alumina powder Download PDF

Info

Publication number
WO2024128317A1
WO2024128317A1 PCT/JP2023/045120 JP2023045120W WO2024128317A1 WO 2024128317 A1 WO2024128317 A1 WO 2024128317A1 JP 2023045120 W JP2023045120 W JP 2023045120W WO 2024128317 A1 WO2024128317 A1 WO 2024128317A1
Authority
WO
WIPO (PCT)
Prior art keywords
alumina powder
spherical alumina
cup
less
measured
Prior art date
Application number
PCT/JP2023/045120
Other languages
French (fr)
Japanese (ja)
Inventor
輝洋 相京
直嗣 野上
Original Assignee
デンカ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by デンカ株式会社 filed Critical デンカ株式会社
Publication of WO2024128317A1 publication Critical patent/WO2024128317A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C01F7/021—After-treatment of oxides or hydroxides
    • C01F7/022—Classification
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F7/00—Compounds of aluminium
    • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
    • C01F7/021—After-treatment of oxides or hydroxides
    • C01F7/027—Treatment involving fusion or vaporisation

Definitions

  • the present invention relates to spherical alumina powder.
  • Patent Document 1 describes spherical alumina powder with an average particle size (D50) of 50 ⁇ m or less and a sphericity of 0.9 or more (e.g., claim 1 of Patent Document 1).
  • the present inventors found that by appropriately controlling one of the particle size distributions of the spherical alumina powder, namely (D 97 -D 10 )/D 50 , it is possible to suppress the generation of burrs during molding using a resin molding material containing the same, and thus completed the present invention.
  • a spherical alumina powder as follows: 1. In a volume frequency particle size distribution measured by a wet laser diffraction scattering method, when the particle size at which the cumulative value is 10% is D10 , the particle size at which the cumulative value is 50% is D50 , and the particle size at which the cumulative value is 97% is D97 , A spherical alumina powder having a (D 97 -D 10 )/D 50 of 4.2 or more and 20.0 or less. 2. The spherical alumina powder according to 1., A spherical alumina powder having a D 97 /D 50 of 5.0 or more and 20.0 or less. 3.
  • the spherical alumina powder according to 1. or 2. A spherical alumina powder, the thixotropy index of a resin varnish for evaluation containing the spherical alumina powder being 0.10 or more and 0.80 or less, as measured according to the following procedure. (procedure)
  • the spherical alumina powder is mixed with bisphenol F type epoxy that is liquid at 25° C. so that the content is 83 mass %, to obtain the above-mentioned resin varnish for evaluation.
  • the viscosity ( ⁇ 1 ) of the obtained resin varnish for evaluation is measured using a rheometer at a shear rate of 2 [1/s] and a shear rate of 20 [1/s] at 25 ° C.
  • the thixotropic index is calculated based on ⁇ 20 / ⁇ 1 . 4.
  • the spherical alumina powder according to any one of 1 to 3 A test sample of the resin composition has a viscosity ⁇ 20 of 10 Pa ⁇ s or more and 200 Pa ⁇ s or less at a shear rate of 20 [1/s]. 5.
  • the spherical alumina powder according to any one of 1. to 4. A spherical alumina powder having a loose bulk density of 1.10 g/ cm3 or more and 1.50 g/ cm3 or less, as measured by the following procedure.
  • the spherical alumina powder is allowed to fall from a height of 25 cm at a rate of 5 to 10 g per minute into a 100 cm3 measuring cup, and the fall is continued until the powder overflows from the cup, to prepare a heaping cup.
  • the overflowing amount is leveled off without tapping, and then the mass (g) of the spherical alumina powder filled in the cup is measured to calculate the loose bulk density (g/cm 3 ).
  • the present invention provides spherical alumina powder that is excellent at suppressing burrs when used in resin molding materials.
  • FIG. 2 is a schematic cross-sectional view showing the configuration of a thermal spraying device.
  • the spherical alumina powder of this embodiment will be described.
  • the volume frequency particle size distribution of the spherical alumina powder is measured by a wet laser diffraction scattering method, and in the obtained volume frequency particle size distribution, the particle size at which the cumulative value is 10% is defined as D10 , the particle size at which the cumulative value is 50% is defined as D50 , and the particle size at which the cumulative value is 97% is defined as D97 .
  • the spherical alumina powder of this embodiment is configured so that (D 97 -D 10 )/D 50 , which is one of the particle size distributions, is 4.2 or more and 20.0 or less.
  • the lower limit of (D 97 -D 10 )/D 50 is at least 4.2, preferably at least 4.5, and more preferably at least 5.0, which can suppress the generation of burrs during molding of a resin molding material containing spherical alumina powder.
  • the upper limit of ( D97 - D10 )/ D50 is 20.0 or less, preferably 15.0 or less, and more preferably 10.0 or less, so that the particle size distribution is not too broad and D50 is not too small, and the flowability and filling property of the powder itself can be improved by keeping the range appropriate.
  • the lower limit of D 97 /D 50 is, for example, 5.0 or more, preferably 5.5 or more, and more preferably 6.0 or more, whereby the particle size distribution has a certain width, and the flowability and moldability can be improved.
  • the upper limit of D 97 /D 50 is, for example, 20.0 or less, preferably 10.0 or less, and more preferably 8.0 or less, whereby the particle size of the coarse particles becomes sharp, and molding defects in the molded product due to the coarse particles can be suppressed.
  • the lower limit of D50 is, for example, 2.0 ⁇ m or more, preferably 3.0 ⁇ m or more, and more preferably 4.0 ⁇ m or more.
  • the upper limit of D50 is, for example, 15.0 ⁇ m or less, preferably 9.0 ⁇ m or less, and more preferably 8.5 ⁇ m or less.
  • the lower limit of D90 is, for example, 20.0 ⁇ m or more, preferably 25.0 ⁇ m or more, and more preferably 30.0 ⁇ m or more.
  • the upper limit of D90 is, for example, 80.0 ⁇ m or less, preferably 70.0 ⁇ m or less, and more preferably 60.0 ⁇ m or less.
  • the particle size distribution of the spherical alumina powder is a value based on particle size measurement by the laser diffraction light scattering method, and can be measured using a particle size distribution measuring device such as the "Model LS-13230" (manufactured by Beckman Coulter).
  • a particle size distribution measuring device such as the "Model LS-13230" (manufactured by Beckman Coulter).
  • water was used as the solvent, and as a pretreatment, the powder was dispersed for 1 minute using a homogenizer at 200 W output.
  • the PIDS (Polarization Intensity Differential Scattering) concentration was adjusted to 45-55%.
  • the refractive index of water was 1.33, and the refractive index of the powder was determined taking into account the refractive index of the powder material.
  • the refractive index of amorphous silica was 1.50
  • the refractive index of alumina was 1.68.
  • the above (D 97 -D 10 )/D 50 and D 97 /D 50 by appropriately selecting, for example, the raw material components of the spherical alumina powder, the manufacturing method of the spherical alumina powder, etc.
  • factors for setting the above (D 97 -D 10 )/D 50 and D 97 /D 50 within the desired numerical range include, for example, appropriately controlling the melting flame conditions such as the raw material supply amount, raw material particle size, flame temperature, combustible gas, combustion supporting gas, and dispersion gas , heating the raw material carrier gas , using alumina raw material powders of different particle sizes in combination, and appropriately adjusting the aperture during classification treatment.
  • the thixotropy index of the evaluation resin varnish containing spherical alumina powder is configured to be, for example, 0.10 or more and 0.80 or less.
  • the thixotropy index of the resin varnish to be evaluated can be measured according to the following procedure.
  • the spherical alumina powder is mixed with bisphenol F type epoxy (Epicoat 807) that is liquid at 25° C. so that the content is 83 mass % to obtain the above-mentioned resin varnish for evaluation.
  • the viscosity ( ⁇ 1 ) of the obtained resin varnish for evaluation is measured using a rheometer at a shear rate of 2 [1/s] and a shear rate of 20 [1/s] at 25 ° C.
  • the thixotropic index is calculated based on ⁇ 20 / ⁇ 1 .
  • the lower limit of the thixotropy index is, for example, 0.10 or more, preferably 0.12 or more, and more preferably 0.15 or more, which can improve the wire sweepability of the resin molding material.
  • the upper limit of the thixotropy index is, for example, 0.80 or less, preferably 0.70 or less, and more preferably 0.60 or less, thereby improving the moldability of the resin molding material.
  • the lower limit of the viscosity ( ⁇ 1 ) of the resin varnish for evaluation at a shear rate of 1 [1/s] is, for example, 100 Pa ⁇ s or more, preferably 120 Pa ⁇ s or more, and more preferably 150 Pa ⁇ s or more. This can improve the handleability of the resin molding material.
  • the upper limit of the viscosity ( ⁇ 1 ) is, for example, 1000 Pa ⁇ s or less, preferably 800 Pa ⁇ s or less, and more preferably 600 Pa ⁇ s or less, which can improve the handleability of the resin molding material and suppress deformation of the wire due to flow pressure during molding.
  • the spherical alumina powder may be configured so that the degree of compression calculated based on ((P-A)/P) x 100, where A is the loose bulk density and P is the compacted bulk density measured according to the following procedure, is, for example, 35% or more and 55% or less.
  • the loose bulk density, the hardened bulk density and the compressibility can be measured according to the following procedure under conditions of a room temperature of 25° C. and a humidity of 55%.
  • the spherical alumina powder is allowed to fall from a height of 25 cm at a rate of 5 to 10 g per minute into a 100 cm3 measuring cup, and the fall is continued until the powder overflows from the cup, to prepare a heaping cup.
  • the overflowing amount is leveled off without tapping, and then the mass (g) of the spherical alumina powder filled in the cup is measured to calculate the loose bulk density (g/cm 3 ).
  • the lower limit of the compression degree is, for example, 35% or more, preferably 38% or more, and more preferably 40% or more, which can improve the handleability of the spherical alumina powder.
  • the upper limit of the compression degree is, for example, 55% or less, preferably 53% or less, and more preferably 50% or less, which can improve the mixability of the resin and the spherical alumina powder.
  • the spherical alumina powder may be configured so as to have a loose bulk density (A) of 1.10 g/cm 3 or more and 1.50 g/cm 3 or less.
  • the lower limit of the loose bulk density (A) is, for example, 1.10 cm 3 /g or more, preferably 1.15 cm 3 /g or more, and more preferably 1.20 cm 3 /g or more. This improves the denseness and may improve the strength of the molded article of the resin molding material.
  • the upper limit of the loose bulk density (A) is, for example, 1.50 cm 3 /g or less, preferably 1.45 cm 3 /g or less, and more preferably 1.40 cm 3 /g or less, which can improve the mixability of the resin and the spherical alumina powder.
  • Spherical alumina powder is produced, for example, by supplying alumina raw material powder into a high-temperature flame formed by the combustion reaction of a combustible gas and a combustion supporting gas, and melting and spheroidizing the powder at a temperature above its melting point.
  • the particles obtained by this type of molten flame method are called molten spherical particles.
  • the obtained molten spherical particles may be further subjected to classification and sieving processing as necessary.
  • For the alumina raw material powder multiple raw material powders with different particle sizes are used.
  • FIG. 1 shows a schematic diagram of an example of a thermal spraying apparatus used for producing molten spherical particles.
  • the thermal spraying device 100 in FIG. 1 is composed of a melting furnace 2 in which a burner 1 is installed, a cyclone 4 for classifying molten spherical particles generated by high-temperature exhaust gas from a flame by suction with a blower 9, and a bag filter 8 for collecting fine powder that cannot be captured by the cyclone 4.
  • the melting furnace 2 is configured as a vertical furnace body, but is not limited to this, and may be a so-called horizontal furnace or inclined furnace that is horizontal and blows out flames horizontally.
  • the hot exhaust gas is cooled by pipes 3 and 5 which are equipped with water-cooled jackets.
  • the blower 9 may be connected to a suction gas amount control valve and a gas exhaust port (not shown).
  • a collected powder removal device (not shown) may be connected to the lower portion of the melting furnace 2, the cyclone 4, and the bag filter 8.
  • the classification can be carried out using known equipment such as a settling chamber, a cyclone, a classifier having a rotor, etc. This classification operation may be incorporated into the transportation process of the molten spheroidized product, or may be carried out in a separate line after collecting the molten spheroidized product all at once.
  • the combustible gas for example, one or more of acetylene, propane, butane, etc. may be used, but propane, butane, or a mixture thereof, which have a relatively small calorific value, is preferred.
  • the combustion supporting gas for example, a gas containing oxygen is used. In general, it is most preferable to use pure oxygen of 99 mass% or more, as it is inexpensive.
  • an inert gas such as air or argon can be mixed with the combustion supporting gas.
  • Alumina powder having an average particle size of, for example, 3 to 70 ⁇ m may be used as the raw material powder, which is the alumina raw material powder.
  • the aluminum hydroxide powder may be supplied to the high-temperature flame in a dry manner or in a wet manner in which it is slurried with water or the like.
  • the spherical alumina powder of the present invention can be blended with a resin composition and used suitably as a resin molding material.
  • the resin composition contains, in addition to the spherical alumina powder of the present invention, a resin and known resin additives.
  • the spherical alumina powder may be used alone or may be mixed with other fillers.
  • the resin composition may contain 10 to 99% by mass of the spherical alumina powder, or 10 to 99% by mass of a mixed inorganic powder containing the spherical alumina powder and other fillers.
  • the content of the other fillers in the mixed inorganic powder may be, for example, 1 to 20% by mass or 3 to 15% by mass relative to 100% by mass of the spherical alumina powder.
  • the range "to" indicates that both the upper and lower limits are included, unless otherwise specified.
  • Examples of the other fillers include crystalline silica, fused silica, titania, silicon nitride, aluminum nitride, silicon carbide, talc, and calcium carbonate.
  • the average particle size of the other fillers is, for example, about 5 to 100 ⁇ m, and there are no particular restrictions on the particle size composition and shape.
  • Examples of the above resins include epoxy resins, silicone resins, phenolic resins, melamine resins, urea resins, unsaturated polyesters, fluororesins, polyamides such as polyimide, polyamideimide, and polyetherimide, polyesters such as polybutylene terephthalate and polyethylene terephthalate, polyphenylene sulfide, wholly aromatic polyesters, polysulfones, liquid crystal polymers, polyethersulfones, polycarbonates, maleimide-modified resins, ABS resins, AAS (acrylonitrile-acrylic rubber-styrene) resins, and AES (acrylonitrile-ethylene-propylene-diene rubber-styrene) resins. These may be used alone or in combination of two or more.
  • the resin composition can be produced, for example, by blending the raw material components in a prescribed ratio using a blender or Henschel mixer, kneading the mixture using a heated roll, kneader, single-screw or twin-screw extruder, etc., cooling the mixture, and then pulverizing it.
  • the thermal spraying device 100 shown in FIG. 1 includes a melting furnace 2, a burner 1 installed in the upper part of the melting furnace 2, and a collection system line installed directly connected to the lower part of the melting furnace 2 and consisting of a cyclone 4 and a bag filter 8.
  • Burner 1 has a double-tube structure capable of forming an inner flame and an outer flame, and is installed at the top of melting furnace 2, to which a combustible gas supply pipe 11, a combustion supporting gas supply pipe 12, and a raw material supply pipe 13 are each connected.
  • raw material powder is fed into the high-temperature flame through a raw material supply pipe 13 and melted to form molten spherical particles.
  • the molten spherical particles that have passed through the melting furnace 2 are sucked in by a blower 9 together with the combustion exhaust gas, moved by the air through pipes 3 and 5, and classified and collected by a cyclone 4 or a bag filter 8.
  • Example 1 Using the above-mentioned thermal spraying device 100, LPG was supplied as a combustible gas from the combustible gas supply pipe 11, and oxygen was supplied as a combustion supporting gas from the combustion supporting gas supply pipe 12. A high-temperature flame was formed in the burner 1 by combustion of the LPG and oxygen. Secondary air is supplied to the cyclone 4 by a rotary valve (not shown) installed in the pipe 3. Air in the atmosphere is used as the secondary air. The degree of opening and closing of the lower valve in the cyclone 4 (lower opening degree) is set to 100%. As the raw material powder, alumina powders having a maximum average particle size (D 50 ) in the range of 2 to 45 ⁇ m were used.
  • D 50 maximum average particle size
  • the supply rates were 15 Nm 3 /hr for the raw material carrier gas heated to 500° C., 5 Nm 3 /hr for the burner combustible gas, and 10 Nm 3 /hr for the combustion supporting gas.
  • the molten spherical particles captured by the bag filter 8 were recovered as spherical alumina powder.
  • Examples 2 to 5 The spherical alumina powder was collected in the same manner as in Example 1 above, except that the lower opening degree during the classification process in the production of the spherical alumina powder was changed to 20%, 25%, 35%, and 45%, respectively.
  • Comparative Example 1 To the spherical alumina powder recovered in the same manner as in Example 1, spherical alumina fine powder (DAW-01, manufactured by Denka Company, Ltd., average particle diameter D 50 : 2 ⁇ m) was added to adjust the particle size distribution in Table 1, thereby obtaining the spherical alumina powder of Comparative Example 1.
  • DWA-01 spherical alumina fine powder
  • Comparative Example 2 To the spherical alumina powder recovered in the same manner as in Example 1, spherical alumina coarse powder (DAW-70, manufactured by Denka Company, average particle diameter D 50 : 45 ⁇ m) was added to adjust the particle size distribution in Table 1, thereby obtaining the spherical alumina powder of Comparative Example 2.
  • DWA-70 spherical alumina coarse powder
  • ⁇ Loose bulk density, hard bulk density> The loose bulk density and the packed bulk density of the obtained spherical alumina powder were measured at room temperature of 25° C. and humidity of 55% using a powder tester (PT-E type, manufactured by Hosokawa Micron Corporation). The specific steps are as follows: The spherical alumina powder sample was allowed to fall from a height of 25 cm at a rate of 5 to 10 g per minute into a 100 cm3 measuring cup. The drop was continued until the powder overflowed from the cup, and a heaping cup was prepared.
  • the overflowing powder was leveled off without tapping, and then the mass (g) of the spherical alumina powder filled in the cup was measured to calculate the loose bulk density (g/cm 3 ).
  • the heaped cup was tapped up and down 180 times (stroke length 2 cm, 1 second/time), and the overflowed powder was leveled off.
  • the mass (g) of the spherical alumina powder filled in the cup was then measured, and the compacted bulk density (g/ cm3 ) was calculated.
  • the loose bulk density obtained by the above procedure is A and the hardened bulk density is P
  • the degree of compression (%) was calculated based on the formula: ((P-A)/P) x 100.
  • the volume frequency particle size distribution of the obtained spherical alumina powder was determined by a wet laser diffraction scattering method using a particle size distribution measuring device (LS-13230, manufactured by Beckman Coulter, Inc.). Water was used as the solvent, and as a pretreatment, the powder was dispersed for 1 minute using a homogenizer at an output of 200 W. The PIDS (Polarization Intensity Differential Scattering) concentration was adjusted to 45 to 55%, and the measurement was performed. Based on the obtained volume frequency particle size distribution, the particle diameter D X at which the cumulative value becomes X% was calculated.
  • ⁇ Viscosity> The obtained spherical alumina powder was mixed with bisphenol F type epoxy (Epicoat 807) in a liquid state at 25° C. so that the content was 83 mass %, to obtain the above-mentioned resin varnish for evaluation.
  • the obtained resin varnish for evaluation was measured for viscosity ( ⁇ 1 ) at a shear rate of 1 [1/s] at 25° C. and viscosity ( ⁇ 20 ) at a shear rate of 20 [1/s] using a rheometer (manufactured by Anton Paar).
  • the obtained ⁇ 1 and ⁇ 20 were used to calculate the "thixotropy index" represented by the formula ⁇ 20 / ⁇ 1 .
  • ⁇ Burring prevention> A mixture of 90.1 parts by mass of the obtained spherical alumina powder, 4.8 parts by mass of biphenylene aralkyl phenol type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name: NC-3000, epoxy equivalent 275, softening point 56° C.), 3.7 parts by mass of phenol resin (phenol aralkyl resin, manufactured by Meiwa Kasei Co., Ltd. MEHC-7800S), 0.19 parts by mass of triphenylphosphine (manufactured by Hokko Chemical Industry Co., Ltd.: TPP), and N-phenyl-3-aminopropyltrimethylamine was used.
  • biphenylene aralkyl phenol type epoxy resin manufactured by Nippon Kayaku Co., Ltd., product name: NC-3000, epoxy equivalent 275, softening point 56° C.
  • phenol resin phenol aralkyl resin, manufactured by Meiwa Kasei Co.
  • toxosilane manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-573
  • a Henschel mixer manufactured by Nippon Coke and Engineering Co., Ltd., "FM-20C/I”
  • screw diameter D 25 mm
  • the obtained resin composition was molded using a burr measurement mold having slits of 2 ⁇ m, 5 ⁇ m, 10 ⁇ m, and 30 ⁇ m at a molding temperature of 175° C. and a molding pressure of 7.4 MPa.
  • the amount of resin that flowed into the slits was measured with a vernier caliper, and the values measured for each slit were averaged to determine the burr length ( ⁇ m).
  • the burr length was 2 mm or less, it was evaluated as being able to suppress the generation of burrs during molding (good), and when it exceeded 2 mm, it was evaluated as being likely to generate burrs during molding (bad).
  • the resin composition obtained above was used in a spiral flow mold in accordance with EMMI-1-66 (Epoxy Molding Material Institute; Society of Plastics Industry).
  • the mold temperature was 175° C.
  • the molding pressure was 7.4 MPa
  • the pressure retention time was 90 seconds.
  • a spiral flow of 150 cm or more was evaluated as good, and a spiral flow of less than 150 cm was evaluated as poor.
  • the resin composition obtained above was poured into a mold having a disk-shaped hole with a diameter of 28 mm and a thickness of 3 mm, and molded at 150°C for 20 minutes after degassing.
  • the thermal conductivity (W/m ⁇ K) of the obtained molded body was measured by a steady method in accordance with ASTM D5470 using a thermal conductivity measuring device (a resin material thermal resistance measuring device "TRM-046RHHT" (product name) manufactured by Hitachi Technology and Services Co., Ltd.).
  • the resin composition was processed to a width of 10 mm x 10 mm, and measurements were performed while applying a load of 2 N.
  • Thermal conductivity (W/m ⁇ K) thickness of molded body (m)/ ⁇ thermal resistance (° C./W) ⁇ heat transfer area (m 2 ) ⁇
  • the spherical alumina powders of Examples 1 to 4 were able to suppress the generation of burrs during molding of the resin composition, and also showed results that could improve the thermal conductivity of the resin molding material.
  • the spherical alumina powders of Examples 1 to 4 showed results that showed excellent flowability when used in the resin molding material.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Inorganic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

Abstract

In a volume frequency particle size distribution of this spherical alumina powder as measured by a wet-type laser diffraction scattering method, when the particle size at which the cumulative value becomes 10% is denoted as D10, the particle size at which the cumulative value becomes 50% is denoted as D50, and the particle size at which the cumulative value becomes 97% is denoted as D97, (D97-D10)/D50 equals 4.2 to 20.0.

Description

球状アルミナ粉末Spherical Alumina Powder
　本発明は、球状アルミナ粉末に関する。 The present invention relates to spherical alumina powder.
　これまで球状アルミナ粉末について様々な開発がなされてきた。この種の技術として、例えば、特許文献１に記載の技術が知られている。特許文献１には、平均粒子径（Ｄ５０）が５０μｍ以下、真球度が０．９以上である球状アルミナ粉末が記載されている（特許文献１の請求項１など）。 Various developments have been made on spherical alumina powder to date. One such technology is described in Patent Document 1. Patent Document 1 describes spherical alumina powder with an average particle size (D50) of 50 μm or less and a sphericity of 0.9 or more (e.g., claim 1 of Patent Document 1).
特開２０１５－１９３４９３号公報JP 2015-193493 A
　しかしながら、本発明者が検討した結果、上記特許文献１に記載の球状アルミナ粉末において、樹脂成形材料に使用したときのバリ発生の点で改善の余地があることが判明した。 However, as a result of the inventor's investigations, it was found that there is room for improvement in terms of the generation of burrs when the spherical alumina powder described in Patent Document 1 is used in resin molding materials.
　本発明者はさらに検討したところ、球状アルミナ粉末の粒度分布の一つである（Ｄ９７－Ｄ１０）／Ｄ５０を適切に制御することにより、これを含む樹脂成形材料を用いた成形時に発生するバリを抑制できることを見出し、本発明を完成するに至った。 As a result of further investigation, the present inventors found that by appropriately controlling one of the particle size distributions of the spherical alumina powder, namely (D 97 -D 10 )/D 50 , it is possible to suppress the generation of burrs during molding using a resin molding material containing the same, and thus completed the present invention.
　本発明の一態様によれば、以下の球状アルミナ粉末が提供される。
１．　湿式によるレーザー回折散乱法で測定される体積頻度粒度分布において、累積値が１０％となる粒子径をＤ１０、累積値が５０％となる粒子径をＤ５０、累積値が９７％となる粒子径をＤ９７としたとき、
　（Ｄ９７－Ｄ１０）／Ｄ５０が、４．２以上２０．０以下である、球状アルミナ粉末。
２．　１．に記載の球状アルミナ粉末であって、
　Ｄ９７／Ｄ５０が、５．０以上２０．０以下である、球状アルミナ粉末。
３．　１．又は２．に記載の球状アルミナ粉末であって、
　下記の手順に従って測定される、当該球状アルミナ粉末を含む評価用樹脂ワニスのチキソ指数が、０．１０以上０．８０以下である、球状アルミナ粉末。
（手順）
　当該球状アルミナ粉末を、含有量が８３質量％となるように、２５℃で液状のビスフェノールＦ型エポキシと混合して、上記の評価用樹脂ワニスを得る。
　続いて、得られた評価用樹脂ワニスにおいて、レオメータを用いて、２５℃下、せん断速度２［１／ｓ］で測定したときの粘度（η１）、およびせん断速度２０［１／ｓ］で測定したときの粘度（η２０）を測定する。上記のチキソ指数を、η２０／η１に基づいて求める。
４．　１．～３．に記載の球状アルミナ粉末であって、
　前記樹脂組成物の試験サンプルにおけるせん断速度：２０［１／ｓ］時における粘度η２０が、１０Ｐａ・ｓ以上２００Ｐａ・ｓ以下である、球状アルミナ粉末。
５．　１．～４．のいずれか一つに記載の球状アルミナ粉末であって、
　下記の手順で測定される、ゆるめ嵩密度が、１．１０ｇ／ｃｍ３以上１．５０ｇ／ｃｍ３以下である、球状アルミナ粉末。
（手順）
　当該球状アルミナ粉末を、１分間に５～１０ｇの投入量で、高さ２５ｃｍから自然落下させ、１００ｃｍ３の測定用カップの内部に投入し、カップから溢れ出るまで続けて、山盛りカップを準備する。
　続いて、山盛りカップについて、タッピングせずに、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、ゆるめ嵩密度（ｇ／ｃｍ３）を算出する。
　一方、山盛りカップについて、上下方向に１８０回の条件（ストローク長２ｃｍ、１秒／回）でタッピングした後で、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、かため嵩密度（ｇ／ｃｍ３）を算出する。
６．　１．～５．に記載の球状アルミナ粉末であって、
　前記手順で測定される、ゆるめ嵩密度をＡ、かため嵩密度をＰとしたとき、
　（（Ｐ－Ａ）／Ｐ）×１００に基づいて求められる圧縮度が、３５％以上５５％以下である、球状アルミナ粉末。 According to one aspect of the present invention, there is provided a spherical alumina powder as follows:
1. In a volume frequency particle size distribution measured by a wet laser diffraction scattering method, when the particle size at which the cumulative value is 10% is D10 , the particle size at which the cumulative value is 50% is D50 , and the particle size at which the cumulative value is 97% is D97 ,
A spherical alumina powder having a (D 97 -D 10 )/D 50 of 4.2 or more and 20.0 or less.
2. The spherical alumina powder according to 1.,
A spherical alumina powder having a D 97 /D 50 of 5.0 or more and 20.0 or less.
3. The spherical alumina powder according to 1. or 2.,
A spherical alumina powder, the thixotropy index of a resin varnish for evaluation containing the spherical alumina powder being 0.10 or more and 0.80 or less, as measured according to the following procedure.
(procedure)
The spherical alumina powder is mixed with bisphenol F type epoxy that is liquid at 25° C. so that the content is 83 mass %, to obtain the above-mentioned resin varnish for evaluation.
Next, the viscosity (η 1 ) of the obtained resin varnish for evaluation is measured using a rheometer at a shear rate of 2 [1/s] and a shear rate of 20 [1/s] at 25 ° C. The thixotropic index is calculated based on η 20 /η 1 .
4. The spherical alumina powder according to any one of 1 to 3,
A test sample of the resin composition has a viscosity η20 of 10 Pa·s or more and 200 Pa·s or less at a shear rate of 20 [1/s].
5. The spherical alumina powder according to any one of 1. to 4.,
A spherical alumina powder having a loose bulk density of 1.10 g/ cm3 or more and 1.50 g/ cm3 or less, as measured by the following procedure.
(procedure)
The spherical alumina powder is allowed to fall from a height of 25 cm at a rate of 5 to 10 g per minute into a 100 cm3 measuring cup, and the fall is continued until the powder overflows from the cup, to prepare a heaping cup.
Next, for the heaping cup, the overflowing amount is leveled off without tapping, and then the mass (g) of the spherical alumina powder filled in the cup is measured to calculate the loose bulk density (g/cm 3 ).
On the other hand, for a heaping cup, after tapping it up and down 180 times (stroke length 2 cm, 1 second/time), the overflowed powder was leveled off from the top of the cup, and the mass (g) of the spherical alumina powder filled in the cup was measured to calculate the compacted bulk density (g/ cm3 ).
6. The spherical alumina powder according to any one of 1 to 5,
When the loose bulk density measured by the above procedure is A and the hard bulk density is P,
A spherical alumina powder having a degree of compression calculated based on ((P−A)/P)×100 of 35% or more and 55% or less.
　本発明によれば、樹脂成形材料に使用したときのバリ抑制に優れた球状アルミナ粉末が提供される。 The present invention provides spherical alumina powder that is excellent at suppressing burrs when used in resin molding materials.
溶射装置の構成を示す模式的断面図である。FIG. 2 is a schematic cross-sectional view showing the configuration of a thermal spraying device.
　以下、本発明の実施の形態について、図面を用いて説明する。なお、すべての図面において、同様な構成要素には同様の符号を付し、適宜説明を省略する。また、図は概略図であり、実際の寸法比率とは一致していない。 Below, an embodiment of the present invention will be described with reference to the drawings. Note that in all drawings, similar components are given similar reference symbols and descriptions will be omitted where appropriate. Also, the drawings are schematic and do not correspond to the actual dimensional ratios.
　本実施形態の球状アルミナ粉末について説明する。 The spherical alumina powder of this embodiment will be described.
　球状アルミナ粉末における体積頻度粒度分布を湿式によるレーザー回折散乱法により測定し、得られた体積頻度粒度分布において、累積値が１０％となる粒子径をＤ１０、累積値が５０％となる粒子径をＤ５０、累積値が９７％となる粒子径をＤ９７とする。 The volume frequency particle size distribution of the spherical alumina powder is measured by a wet laser diffraction scattering method, and in the obtained volume frequency particle size distribution, the particle size at which the cumulative value is 10% is defined as D10 , the particle size at which the cumulative value is 50% is defined as D50 , and the particle size at which the cumulative value is 97% is defined as D97 .
　本実施形態の球状アルミナ粉末は、粒度分布の一つである（Ｄ９７－Ｄ１０）／Ｄ５０が、４．２以上２０．０以下となるように構成される。
　（Ｄ９７－Ｄ１０）／Ｄ５０の下限は、４．２以上、好ましくは４．５以上、より好ましくは５．０以上である。これにより、球状アルミナ粉末を含む樹脂成形材料の成形時におけるバリ発生を抑制できる。
　また、（Ｄ９７－Ｄ１０）／Ｄ５０の上限は、２０．０以下、好ましくは１５．０以下、より好ましくは１０．０以下である。これにより、粒度分布が広くなりすぎたり、Ｄ５０が小さくなりすぎたりすることなく、適切な範囲にあることで、粉体自身の流動性、充填性が向上できる。 The spherical alumina powder of this embodiment is configured so that (D 97 -D 10 )/D 50 , which is one of the particle size distributions, is 4.2 or more and 20.0 or less.
The lower limit of (D 97 -D 10 )/D 50 is at least 4.2, preferably at least 4.5, and more preferably at least 5.0, which can suppress the generation of burrs during molding of a resin molding material containing spherical alumina powder.
The upper limit of ( D97 - D10 )/ D50 is 20.0 or less, preferably 15.0 or less, and more preferably 10.0 or less, so that the particle size distribution is not too broad and D50 is not too small, and the flowability and filling property of the powder itself can be improved by keeping the range appropriate.
　Ｄ９７／Ｄ５０の下限は、例えば、５．０以上、好ましくは５．５以上、より好ましくは６．０以上である。これにより、粒度分布が一定の幅を持ち、流動性および成形性が向上できる。
　また、Ｄ９７／Ｄ５０の上限は、例えば、２０．０以下、好ましくは１０．０以下、より好ましくは８．０以下である。これにより、粗大な粒子の粒度がシャープになり、粗大な粒子による成形体の成形不良を抑制できる。 The lower limit of D 97 /D 50 is, for example, 5.0 or more, preferably 5.5 or more, and more preferably 6.0 or more, whereby the particle size distribution has a certain width, and the flowability and moldability can be improved.
The upper limit of D 97 /D 50 is, for example, 20.0 or less, preferably 10.0 or less, and more preferably 8.0 or less, whereby the particle size of the coarse particles becomes sharp, and molding defects in the molded product due to the coarse particles can be suppressed.
　Ｄ５０の下限は、例えば、２．０μｍ以上、好ましくは３．０μｍ以上、より好ましくは４．０μｍ以上である。
　また、Ｄ５０の上限は、例えば、１５．０μｍ以下、好ましくは９．０μｍ以下、より好ましくは８．５μｍ以下である。 The lower limit of D50 is, for example, 2.0 μm or more, preferably 3.0 μm or more, and more preferably 4.0 μm or more.
The upper limit of D50 is, for example, 15.0 μm or less, preferably 9.0 μm or less, and more preferably 8.5 μm or less.
　Ｄ９０の下限は、例えば、２０．０μｍ以上、好ましくは２５．０μｍ以上、より好ましくは３０．０μｍ以上である。
　また、Ｄ９０の上限は、例えば、８０．０μｍ以下、好ましくは７０．０μｍ以下、より好ましくは６０．０μｍ以下である。 The lower limit of D90 is, for example, 20.0 μm or more, preferably 25.0 μm or more, and more preferably 30.0 μm or more.
The upper limit of D90 is, for example, 80.0 μm or less, preferably 70.0 μm or less, and more preferably 60.0 μm or less.
　球状アルミナ粉末の粒度分布は、レーザー回折光散乱法による粒度測定に基づく値であり、粒度分布測定機としては、例えば「モデルＬＳ－１３２３０」（ベックマンコールター社製）にて測定することができる。測定に際しては、溶媒には水を用い、前処理として、１分間、ホモジナイザーを用いて２００Ｗの出力をかけて分散処理させた。また、ＰＩＤＳ（ＰｏｌａｒｉｚａｔｉｏｎＩｎｔｅｎｓｉｔｙＤｉｆｆｅｒｅｎｔｉａｌＳｃａｔｔｅｒｉｎｇ）濃度を４５～５５％になるように調製した。なお、水の屈折率には１．３３を用い、粉末の屈折率については粉末の材質の屈折率を考慮した。たとえば、非晶質シリカについては屈折率を１．５０、アルミナについては屈折率を１．６８として測定した。 The particle size distribution of the spherical alumina powder is a value based on particle size measurement by the laser diffraction light scattering method, and can be measured using a particle size distribution measuring device such as the "Model LS-13230" (manufactured by Beckman Coulter). For the measurement, water was used as the solvent, and as a pretreatment, the powder was dispersed for 1 minute using a homogenizer at 200 W output. The PIDS (Polarization Intensity Differential Scattering) concentration was adjusted to 45-55%. The refractive index of water was 1.33, and the refractive index of the powder was determined taking into account the refractive index of the powder material. For example, the refractive index of amorphous silica was 1.50, and the refractive index of alumina was 1.68.
　詳細なメカニズムは定かではないが、上記の球状アルミナ粉末の粒度分布を制御することにより、樹脂に配合したときの樹脂成形材料（樹脂組成物）において、適当な粘弾特性を実現できるため、成形時におけるバリ発生を抑制できると、考えられる。 Although the detailed mechanism is unclear, it is believed that by controlling the particle size distribution of the above-mentioned spherical alumina powder, it is possible to achieve appropriate viscoelastic properties in the resin molding material (resin composition) when it is mixed with resin, thereby suppressing the occurrence of burrs during molding.
　本実施形態では、たとえば球状アルミナ粉末の原料成分や、球状アルミナ粉末の製造方法等を適切に選択することにより、上記（Ｄ９７－Ｄ１０）／Ｄ５０およびＤ９７／Ｄ５０を制御することが可能である。これらの中でも、たとえば原料供給量、原料粒径、火炎温度、可燃性ガス、助燃ガス、分散ガス等の溶融火炎条件を適切に制御すること、原料のキャリアガスを加熱すること、異なる粒径のアルミナ原料粉末を併用すること、分級処理時における開度を適切に調整すること等が、上記（Ｄ９７－Ｄ１０）／Ｄ５０およびＤ９７／Ｄ５０を所望の数値範囲とするための要素として挙げられる。 In this embodiment, it is possible to control the above (D 97 -D 10 )/D 50 and D 97 /D 50 by appropriately selecting, for example, the raw material components of the spherical alumina powder, the manufacturing method of the spherical alumina powder, etc. Among these, factors for setting the above (D 97 -D 10 )/D 50 and D 97 /D 50 within the desired numerical range include, for example, appropriately controlling the melting flame conditions such as the raw material supply amount, raw material particle size, flame temperature, combustible gas, combustion supporting gas, and dispersion gas , heating the raw material carrier gas , using alumina raw material powders of different particle sizes in combination, and appropriately adjusting the aperture during classification treatment.
　本実施形態において、球状アルミナ粉末を含む評価用樹脂ワニスのチキソ指数は、例えば、０．１０以上０．８０以下となるように構成される。 In this embodiment, the thixotropy index of the evaluation resin varnish containing spherical alumina powder is configured to be, for example, 0.10 or more and 0.80 or less.
　評価用樹脂ワニスのチキソ指数は、以下の手順に従って測定できる。
　当該球状アルミナ粉末を、含有量が８３質量％となるように、２５℃で液状のビスフェノールＦ型エポキシ（エピコート８０７）と混合して、上記の評価用樹脂ワニスを得る。
　続いて、得られた評価用樹脂ワニスにおいて、レオメータを用いて、２５℃下、せん断速度２［１／ｓ］で測定したときの粘度（η１）、およびせん断速度２０［１／ｓ］で測定したときの粘度（η２０）を測定する。上記のチキソ指数を、η２０／η１に基づいて求める。 The thixotropy index of the resin varnish to be evaluated can be measured according to the following procedure.
The spherical alumina powder is mixed with bisphenol F type epoxy (Epicoat 807) that is liquid at 25° C. so that the content is 83 mass % to obtain the above-mentioned resin varnish for evaluation.
Next, the viscosity (η 1 ) of the obtained resin varnish for evaluation is measured using a rheometer at a shear rate of 2 [1/s] and a shear rate of 20 [1/s] at 25 ° C. The thixotropic index is calculated based on η 20 /η 1 .
　上記チキソ指数の下限は、例えば、０．１０以上、好ましくは０．１２以上、より好ましくは０．１５以上である。これにより、樹脂成形材料のワイヤースイープ性を向上できる。
　また、上記チキソ指数の上限は、例えば、０．８０以下、好ましくは０．７０以下、より好ましくは０．６０以下である。これにより、樹脂成形材料の成形性を向上できる。 The lower limit of the thixotropy index is, for example, 0.10 or more, preferably 0.12 or more, and more preferably 0.15 or more, which can improve the wire sweepability of the resin molding material.
The upper limit of the thixotropy index is, for example, 0.80 or less, preferably 0.70 or less, and more preferably 0.60 or less, thereby improving the moldability of the resin molding material.
　上記評価用樹脂ワニスにおけるせん断速度１［１／ｓ］時の粘度（η１）の下限は、例えば、１００Ｐａ・ｓ以上、好ましくは１２０Ｐａ・ｓ以上、より好ましくは１５０Ｐａ・ｓ以上である。これにより、樹脂成形材料のハンドリング性の向上できる。
　また、上記の粘度（η１）の上限は、例えば、１０００Ｐａ・ｓ以下、好ましくは８００Ｐａ・ｓ以下、より好ましくは６００Ｐａ・ｓ以下である。これにより、樹脂成形材料のハンドリング性を向上や成型時の流動圧によるワイヤーが変形を抑制することができる。 The lower limit of the viscosity (η 1 ) of the resin varnish for evaluation at a shear rate of 1 [1/s] is, for example, 100 Pa·s or more, preferably 120 Pa·s or more, and more preferably 150 Pa·s or more. This can improve the handleability of the resin molding material.
The upper limit of the viscosity (η 1 ) is, for example, 1000 Pa·s or less, preferably 800 Pa·s or less, and more preferably 600 Pa·s or less, which can improve the handleability of the resin molding material and suppress deformation of the wire due to flow pressure during molding.
　球状アルミナ粉末は、下記の手順で測定される、ゆるめ嵩密度をＡ、かため嵩密度をＰとしたとき、（（Ｐ－Ａ）／Ｐ）×１００に基づいて求められる圧縮度が、例えば、３５％以上５５％以下となるように構成されてもよい。 The spherical alumina powder may be configured so that the degree of compression calculated based on ((P-A)/P) x 100, where A is the loose bulk density and P is the compacted bulk density measured according to the following procedure, is, for example, 35% or more and 55% or less.
　ゆるめ嵩密度、かため嵩密度、圧縮度は、室温２５℃、湿度５５％の条件下、次の手順に従って測定できる。
　当該球状アルミナ粉末を、１分間に５～１０ｇの投入量で、高さ２５ｃｍから自然落下させ、１００ｃｍ３の測定用カップの内部に投入し、カップから溢れ出るまで続けて、山盛りカップを準備する。
　続いて、山盛りカップについて、タッピングせずに、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、ゆるめ嵩密度（ｇ／ｃｍ３）を算出する。
　一方、山盛りカップについて、上下方向に１８０回の条件（ストローク長２ｃｍ、１秒／回）でタッピングした後で、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、かため嵩密度（ｇ／ｃｍ３）を算出する。
　上記手順により求めた、ゆるめ嵩密度（Ａ）およびかため嵩密度（Ｐ）を用いて、（（Ｐ－Ａ）／Ｐ）×１００に基づいて、圧縮度（％）を算出する。 The loose bulk density, the hardened bulk density and the compressibility can be measured according to the following procedure under conditions of a room temperature of 25° C. and a humidity of 55%.
The spherical alumina powder is allowed to fall from a height of 25 cm at a rate of 5 to 10 g per minute into a 100 cm3 measuring cup, and the fall is continued until the powder overflows from the cup, to prepare a heaping cup.
Next, for the heaping cup, the overflowing amount is leveled off without tapping, and then the mass (g) of the spherical alumina powder filled in the cup is measured to calculate the loose bulk density (g/cm 3 ).
On the other hand, for a heaping cup, after tapping it up and down 180 times (stroke length 2 cm, 1 second/time), the overflowed powder was leveled off from the top of the cup, and the mass (g) of the spherical alumina powder filled in the cup was measured to calculate the compacted bulk density (g/ cm3 ).
Using the loose bulk density (A) and the hardened bulk density (P) obtained by the above procedure, the compressibility (%) is calculated based on ((P−A)/P)×100.
　圧縮度の下限は、例えば、３５％以上、好ましくは３８％以上、より好ましくは４０％以上である。これにより、球状アルミナ粉末のハンドリング性を向上できる。
　また、圧縮度の上限は、例えば、５５％以下、好ましくは５３％以下、より好ましくは５０％以下である。これにより、樹脂と球状アルミナ粉末との混合性を向上できる。 The lower limit of the compression degree is, for example, 35% or more, preferably 38% or more, and more preferably 40% or more, which can improve the handleability of the spherical alumina powder.
The upper limit of the compression degree is, for example, 55% or less, preferably 53% or less, and more preferably 50% or less, which can improve the mixability of the resin and the spherical alumina powder.
　球状アルミナ粉末は、ゆるめ嵩密度（Ａ）が１．１０ｇ／ｃｍ３以上１．５０ｇ／ｃｍ３以下となるように構成されてもよい。
　ゆるめ嵩密度（Ａ）の下限は、例えば、１．１０ｃｍ３／ｇ以上、好ましくは１．１５ｃｍ３／ｇ以上、より好ましくは１．２０ｃｍ３／ｇ以上である。これにより、緻密性が向上し、樹脂成形材料の成形体における強度向上の可能性がある。
　また、ゆるめ嵩密度（Ａ）の上限は、例えば、１．５０ｃｍ３／ｇ以下、好ましくは１．４５ｃｍ３／ｇ以下、より好ましくは１．４０ｃｍ３／ｇ以下である。これにより、樹脂と球状アルミナ粉末との混合性を向上できる。 The spherical alumina powder may be configured so as to have a loose bulk density (A) of 1.10 g/cm 3 or more and 1.50 g/cm 3 or less.
The lower limit of the loose bulk density (A) is, for example, 1.10 cm 3 /g or more, preferably 1.15 cm 3 /g or more, and more preferably 1.20 cm 3 /g or more. This improves the denseness and may improve the strength of the molded article of the resin molding material.
The upper limit of the loose bulk density (A) is, for example, 1.50 cm 3 /g or less, preferably 1.45 cm 3 /g or less, and more preferably 1.40 cm 3 /g or less, which can improve the mixability of the resin and the spherical alumina powder.
　本実施形態の球状アルミナ粉末の製造方法について説明する。 The method for producing the spherical alumina powder of this embodiment will be described.
　球状アルミナ粉末は、例えば、可燃ガスと助燃ガスとの燃焼反応によって形成される高温火炎中に、アルミナ原料粉末を供給し、その融点以上で溶融球状化して製造される。このような溶融火炎法により得られた粒子を溶融球状粒子と呼称する。得られた溶融球状粒子は、必要に応じて、分級・篩分処理をさらに施してもよい。アルミナ原料粉末には、異なる粒子径の原料粉末を複数使用する。 Spherical alumina powder is produced, for example, by supplying alumina raw material powder into a high-temperature flame formed by the combustion reaction of a combustible gas and a combustion supporting gas, and melting and spheroidizing the powder at a temperature above its melting point. The particles obtained by this type of molten flame method are called molten spherical particles. The obtained molten spherical particles may be further subjected to classification and sieving processing as necessary. For the alumina raw material powder, multiple raw material powders with different particle sizes are used.
　溶融球状粒子を製造するために用いる溶射装置の概略図の一例を図１に示す。
　図１の溶射装置１００は、バーナー１が設置された溶融炉２と、火炎の高温排ガスで生成した溶融球状粒子を、ブロワー９の吸引にて分級するためのサイクロン４と、サイクロン４で捕集できなかった微粉を回収するバグフィルター８と、により構成されている。
　溶融炉２は、縦型炉体で構成されるが、これに限定されず、横型にして火炎を水平方向に吹き出す、いわゆる横型炉又は傾斜炉であってもよい。
　高温排ガスは、水冷ジャケットを備える配管３，５によって冷却される。
　ブロワー９には、不図示の吸引ガス量制御バルブ、およびガス排気口が接続されていてもよい。
　溶融炉２、サイクロン４、およびバグフィルター８の下部には、不図示の捕集粉抜き出し装置が接続されていてもよい。
　分級は、重沈室、サイクロン、回転翼を有する分級機等公知の機器を用いて行うことができる。この分級操作は、溶融球状化品の輸送工程に織り込んで行ってもよく、また一括捕集してから別ラインで行ってもよい。 FIG. 1 shows a schematic diagram of an example of a thermal spraying apparatus used for producing molten spherical particles.
The thermal spraying device 100 in FIG. 1 is composed of a melting furnace 2 in which a burner 1 is installed, a cyclone 4 for classifying molten spherical particles generated by high-temperature exhaust gas from a flame by suction with a blower 9, and a bag filter 8 for collecting fine powder that cannot be captured by the cyclone 4.
The melting furnace 2 is configured as a vertical furnace body, but is not limited to this, and may be a so-called horizontal furnace or inclined furnace that is horizontal and blows out flames horizontally.
The hot exhaust gas is cooled by pipes 3 and 5 which are equipped with water-cooled jackets.
The blower 9 may be connected to a suction gas amount control valve and a gas exhaust port (not shown).
A collected powder removal device (not shown) may be connected to the lower portion of the melting furnace 2, the cyclone 4, and the bag filter 8.
The classification can be carried out using known equipment such as a settling chamber, a cyclone, a classifier having a rotor, etc. This classification operation may be incorporated into the transportation process of the molten spheroidized product, or may be carried out in a separate line after collecting the molten spheroidized product all at once.
　可燃ガスとしては、例えば、アセチレン、プロパン、ブタン等の１種又は２種以上が使用されるが発熱量の比較的小さいプロパン、ブタン又はその混合ガスが好ましい。
　助燃ガスとしては、例えば、酸素を含むガスが使用される。一般的には、９９質量％以上の純酸素を用いるのが安価で最も好ましい。ガスの発熱量低減を目的とし、空気やアルゴン等の不活性ガスを助燃ガスに混合することもできる。 As the combustible gas, for example, one or more of acetylene, propane, butane, etc. may be used, but propane, butane, or a mixture thereof, which have a relatively small calorific value, is preferred.
As the combustion supporting gas, for example, a gas containing oxygen is used. In general, it is most preferable to use pure oxygen of 99 mass% or more, as it is inexpensive. In order to reduce the calorific value of the gas, an inert gas such as air or argon can be mixed with the combustion supporting gas.
　原料粉末であるアルミナ原料粉末として、例えば、平均粒径が３～７０μｍのアルミナ粉末を使用してもよい。水酸化アルミニウム粉末の高温火炎中への供給は、乾式又は水等でスラリー化した湿式でもよい。 Alumina powder having an average particle size of, for example, 3 to 70 μm may be used as the raw material powder, which is the alumina raw material powder. The aluminum hydroxide powder may be supplied to the high-temperature flame in a dry manner or in a wet manner in which it is slurried with water or the like.
　本発明の球状アルミナ粉末を樹脂組成物に配合したものを、樹脂成形材料として好適に使用できる。 The spherical alumina powder of the present invention can be blended with a resin composition and used suitably as a resin molding material.
　樹脂組成物は、本発明の球状アルミナ粉末の他に、樹脂や公知の樹脂添加剤などを含む。
　樹脂組成物中に、球状アルミナ粉末は、単独で使用してもよいが、その他のフィラーと混合して使用してもよい。樹脂組成物中には、球状アルミナ粉末が１０～９９質量％含まれていてもよく、または球状アルミナ粉末およびその他のフィラーを含む混合無機粉末が１０～９９質量％含まれていてもよい。また、混合無機粉末中、その他のフィラーの含有量は、球状アルミナ粉末１００質量％に対して、例えば、１～２０質量％、３～１５質量％であってもよい。
　なお、本明細書中、「～」は、特に明示しない限り、上限値と下限値を含むことを表す。 The resin composition contains, in addition to the spherical alumina powder of the present invention, a resin and known resin additives.
In the resin composition, the spherical alumina powder may be used alone or may be mixed with other fillers. The resin composition may contain 10 to 99% by mass of the spherical alumina powder, or 10 to 99% by mass of a mixed inorganic powder containing the spherical alumina powder and other fillers. The content of the other fillers in the mixed inorganic powder may be, for example, 1 to 20% by mass or 3 to 15% by mass relative to 100% by mass of the spherical alumina powder.
In this specification, the range "to" indicates that both the upper and lower limits are included, unless otherwise specified.
　上記のその他のフィラーとしては、例えば、結晶性シリカ、溶融シリカ、チタニア、窒化珪素、窒化アルミニウム、炭化珪素、タルク、炭酸カルシウム等が挙げられる。
　その他のフィラーの平均粒子径は、例えば、５～１００μｍ程度のものが使用され、その粒度構成及び形状については特に制約はない。 Examples of the other fillers include crystalline silica, fused silica, titania, silicon nitride, aluminum nitride, silicon carbide, talc, and calcium carbonate.
The average particle size of the other fillers is, for example, about 5 to 100 μm, and there are no particular restrictions on the particle size composition and shape.
　上記の樹脂としては、例えば、エポキシ樹脂、シリコーン樹脂、フェノール樹脂、メラミン樹脂、ユリア樹脂、不飽和ポリエステル、フッ素樹脂、ポリイミド、ポリアミドイミド、ポリエーテルイミド等のポリアミド、ポリブチレンテレフタレート、ポリエチレンテレフタレート等のポリエステル、ポリフェニレンスルフィド、全芳香族ポリエステル、ポリスルホン、液晶ポリマー、ポリエーテルスルホン、ポリカーボネイト、マレイミド変成樹脂、ＡＢＳ樹脂、ＡＡＳ（アクリロニトリルーアクリルゴム・スチレン）樹脂、ＡＥＳ（アクリロニトリル・エチレン・プロピレン・ジエンゴムースチレン）樹脂等が挙げられる。これらを単独で用いても２種以上を組み合わせて用いてもよい。 Examples of the above resins include epoxy resins, silicone resins, phenolic resins, melamine resins, urea resins, unsaturated polyesters, fluororesins, polyamides such as polyimide, polyamideimide, and polyetherimide, polyesters such as polybutylene terephthalate and polyethylene terephthalate, polyphenylene sulfide, wholly aromatic polyesters, polysulfones, liquid crystal polymers, polyethersulfones, polycarbonates, maleimide-modified resins, ABS resins, AAS (acrylonitrile-acrylic rubber-styrene) resins, and AES (acrylonitrile-ethylene-propylene-diene rubber-styrene) resins. These may be used alone or in combination of two or more.
　樹脂組成物は、例えば、所定量比の原料成分をブレンダーやヘンシェルミキサー等によりブレンドした後、加熱ロール、ニーダー、一軸又は二軸押し出し機等により混練したものを冷却後、粉砕することによって製造することができる。 The resin composition can be produced, for example, by blending the raw material components in a prescribed ratio using a blender or Henschel mixer, kneading the mixture using a heated roll, kneader, single-screw or twin-screw extruder, etc., cooling the mixture, and then pulverizing it.
　以上、本発明の実施形態について述べたが、これらは本発明の例示であり、上記以外の様々な構成を採用することができる。また、本発明は上述の実施形態に限定されるものではなく、本発明の目的を達成できる範囲での変形、改良等は本発明に含まれる。 The above describes the embodiments of the present invention, but these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of the present invention are included in the present invention.
　以下、本発明について実施例を参照して詳細に説明するが、本発明は、これらの実施例の記載に何ら限定されるものではない。 The present invention will be described in detail below with reference to examples, but the present invention is not limited to the description of these examples.
＜球状アルミナ粉末の製造＞
　図１に示す溶射装置１００を用いて、球状アルミナ粉末を製造した。
　図１に示す溶射装置１００は、溶融炉２と、溶融炉２の上部に設置されたバーナー１と、溶融炉２の下部に直結して設置された、サイクロン４およびバグフィルター８からなる捕集系ラインと、を備える。
　バーナー１は、内炎と外炎とを形成できる二重管構造を有していて、溶融炉２の頂上部に設置されており、可燃ガス供給管１１、助燃ガス供給管１２、原料供給管１３の各々が接続されている。
　溶融炉２内では、原料供給管１３より原料粉末を高温火炎中に供給し、溶融させて、球状化した溶融球状粒子を形成できる。溶融炉２を通過した溶融球状粒子は、燃焼排ガスとともにブロワー９により吸引され、配管３，５内を空気により移動し、サイクロン４またはバグフィルター８にて分級・捕集される。 <Production of spherical alumina powder>
A spherical alumina powder was produced using the thermal spraying apparatus 100 shown in FIG.
The thermal spraying device 100 shown in FIG. 1 includes a melting furnace 2, a burner 1 installed in the upper part of the melting furnace 2, and a collection system line installed directly connected to the lower part of the melting furnace 2 and consisting of a cyclone 4 and a bag filter 8.
Burner 1 has a double-tube structure capable of forming an inner flame and an outer flame, and is installed at the top of melting furnace 2, to which a combustible gas supply pipe 11, a combustion supporting gas supply pipe 12, and a raw material supply pipe 13 are each connected.
In the melting furnace 2, raw material powder is fed into the high-temperature flame through a raw material supply pipe 13 and melted to form molten spherical particles. The molten spherical particles that have passed through the melting furnace 2 are sucked in by a blower 9 together with the combustion exhaust gas, moved by the air through pipes 3 and 5, and classified and collected by a cyclone 4 or a bag filter 8.
（実施例１）
　上記の溶射装置１００を用いて、可燃性ガスとしてＬＰＧを可燃ガス供給管１１から供給し、助燃ガスとして酸素を助燃ガス供給管１２から供給し、バーナー１において、ＬＰＧと酸素との燃焼により高温火炎を形成した。
　サイクロン４に対して、配管３に設置された不図示のロータリーバルブにより二次エアーを供給する。二次エアーには、大気中の空気を使用した。また、サイクロン４における下部の弁の開閉度合（下部開度）を１００％とした。
　なお、原料粉末として、平均粒径（Ｄ５０）が２～４５μｍの範囲に極大値を有するアルミナ粉末を複数使用した。供給量は、５００℃に加熱された原料のキャリアガスが１５Ｎｍ３／ｈｒ、バーナーの可燃性ガスが５Ｎｍ３／ｈｒ、助燃ガスが１０Ｎｍ３／ｈｒとした。バグフィルター８にて捕集された溶融球状粒子を、球状アルミナ粉末として回収した。 Example 1
Using the above-mentioned thermal spraying device 100, LPG was supplied as a combustible gas from the combustible gas supply pipe 11, and oxygen was supplied as a combustion supporting gas from the combustion supporting gas supply pipe 12. A high-temperature flame was formed in the burner 1 by combustion of the LPG and oxygen.
Secondary air is supplied to the cyclone 4 by a rotary valve (not shown) installed in the pipe 3. Air in the atmosphere is used as the secondary air. The degree of opening and closing of the lower valve in the cyclone 4 (lower opening degree) is set to 100%.
As the raw material powder, alumina powders having a maximum average particle size (D 50 ) in the range of 2 to 45 μm were used. The supply rates were 15 Nm 3 /hr for the raw material carrier gas heated to 500° C., 5 Nm 3 /hr for the burner combustible gas, and 10 Nm 3 /hr for the combustion supporting gas. The molten spherical particles captured by the bag filter 8 were recovered as spherical alumina powder.
（実施例２～５）
　球状アルミナ粉末の製造において分級処理の際、下部開度を、それぞれ２０％、２５％、３５％、４５％に変更した以外は、上記の実施例１と同様にして、球状アルミナ粉末を回収した。 (Examples 2 to 5)
The spherical alumina powder was collected in the same manner as in Example 1 above, except that the lower opening degree during the classification process in the production of the spherical alumina powder was changed to 20%, 25%, 35%, and 45%, respectively.
（比較例１）
　実施例１と同様にして回収した球状アルミナ粉末に対して、球状アルミナ微粉（デンカ社製、ＤＡＷ－０１、平均粒子径Ｄ５０：２μｍ）を添加して、表１の粒度分布を調整し、比較例１の球状アルミナ粉末を得た。 (Comparative Example 1)
To the spherical alumina powder recovered in the same manner as in Example 1, spherical alumina fine powder (DAW-01, manufactured by Denka Company, Ltd., average particle diameter D 50 : 2 μm) was added to adjust the particle size distribution in Table 1, thereby obtaining the spherical alumina powder of Comparative Example 1.
（比較例２）
　実施例１と同様にして回収した球状アルミナ粉末に対して、球状アルミナ粗粉（デンカ社製、ＤＡＷ－７０、平均粒子径Ｄ５０：４５μｍ）を添加して、表１の粒度分布を調整し、比較例２の球状アルミナ粉末を得た。 (Comparative Example 2)
To the spherical alumina powder recovered in the same manner as in Example 1, spherical alumina coarse powder (DAW-70, manufactured by Denka Company, average particle diameter D 50 : 45 μm) was added to adjust the particle size distribution in Table 1, thereby obtaining the spherical alumina powder of Comparative Example 2.
＜ゆるめ嵩密度、かため嵩密度＞
　得られた球状アルミナ粉末において、室温２５℃、湿度５５％の条件下、パウダーテスター（ホソカワミクロン社製、ＰＴ－Ｅ型）を用いて、ゆるめ嵩密度及びかため嵩密度を測定した。
　具体的な手順は以下の通り。
　測定サンプルである球状アルミナ粉末を、１分間に５～１０ｇの投入量で、高さ２５ｃｍから自然落下させ、１００ｃｍ３の測定用カップの内部に投入し、カップから溢れ出るまで続けて、山盛りカップを準備した。
　続いて、山盛りカップについて、タッピングせずに、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、ゆるめ嵩密度（ｇ／ｃｍ３）を算出した。
　一方、山盛りカップについて、上下方向に１８０回の条件（ストローク長２ｃｍ、１秒／回）でタッピングした後で、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、かため嵩密度（ｇ／ｃｍ３）を算出した。
　上記の手順で求められた、ゆるめ嵩密度をＡ、かため嵩密度をＰとしたとき、圧縮度（％）を、式：（（Ｐ－Ａ）／Ｐ）×１００に基づいて求めた。 <Loose bulk density, hard bulk density>
The loose bulk density and the packed bulk density of the obtained spherical alumina powder were measured at room temperature of 25° C. and humidity of 55% using a powder tester (PT-E type, manufactured by Hosokawa Micron Corporation).
The specific steps are as follows:
The spherical alumina powder sample was allowed to fall from a height of 25 cm at a rate of 5 to 10 g per minute into a 100 cm3 measuring cup. The drop was continued until the powder overflowed from the cup, and a heaping cup was prepared.
Next, for the heaping cup, the overflowing powder was leveled off without tapping, and then the mass (g) of the spherical alumina powder filled in the cup was measured to calculate the loose bulk density (g/cm 3 ).
On the other hand, the heaped cup was tapped up and down 180 times (stroke length 2 cm, 1 second/time), and the overflowed powder was leveled off. The mass (g) of the spherical alumina powder filled in the cup was then measured, and the compacted bulk density (g/ cm3 ) was calculated.
When the loose bulk density obtained by the above procedure is A and the hardened bulk density is P, the degree of compression (%) was calculated based on the formula: ((P-A)/P) x 100.
＜粒度分布＞
　得られた球状アルミナ粉末について、粒度分布測定装置（ベックマンコールター社製、ＬＳ－１３２３０）を用いて、湿式によるレーザー回折散乱法により体積頻度粒度分布を求めた。溶媒には水を用い、前処理として、１分間、ホモジナイザーを用いて２００Ｗの出力をかけて分散処理させた。また、ＰＩＤＳ（Ｐｏｌａｒｉｚａｔｉｏｎ　Ｉｎｔｅｎｓｉｔｙ　Ｄｉｆｆｅｒｅｎｔｉａｌ　Ｓｃａｔｔｅｒｉｎｇ）濃度を４５～５５％になるように調製して測定した。
　得られた体積頻度粒度分布に基づいて、累積値がＸ％となる粒子径ＤＸを算出した。 <Particle size distribution>
The volume frequency particle size distribution of the obtained spherical alumina powder was determined by a wet laser diffraction scattering method using a particle size distribution measuring device (LS-13230, manufactured by Beckman Coulter, Inc.). Water was used as the solvent, and as a pretreatment, the powder was dispersed for 1 minute using a homogenizer at an output of 200 W. The PIDS (Polarization Intensity Differential Scattering) concentration was adjusted to 45 to 55%, and the measurement was performed.
Based on the obtained volume frequency particle size distribution, the particle diameter D X at which the cumulative value becomes X% was calculated.
＜粘度＞
　得られた球状アルミナ粉末を、含有量が８３質量％となるように、２５℃で液状のビスフェノールＦ型エポキシ（エピコート８０７）と混合して、上記の評価用樹脂ワニスを得た。
　得られた評価用樹脂ワニスについて、レオメータ（ＡｎｔｏｎＰａａｒ社製）を用いて、２５℃せん断速度１［１／ｓ］で測定した粘度（η１）、およびせん断速度２０［１／ｓ］で測定した時の粘度（η２０）を測定した。得られたη１、η２０を用いて、式η２０／η１で表される「チキソ指数」を求めた。 <Viscosity>
The obtained spherical alumina powder was mixed with bisphenol F type epoxy (Epicoat 807) in a liquid state at 25° C. so that the content was 83 mass %, to obtain the above-mentioned resin varnish for evaluation.
The obtained resin varnish for evaluation was measured for viscosity (η 1 ) at a shear rate of 1 [1/s] at 25° C. and viscosity (η 20 ) at a shear rate of 20 [1/s] using a rheometer (manufactured by Anton Paar). The obtained η 1 and η 20 were used to calculate the "thixotropy index" represented by the formula η 20 /η 1 .
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　得られた各実施例および各比較例の球状アルミナ粉末について、以下の評価を実施した。
　結果を表１に示す。表１中、「－」は未測定を意味する。 The spherical alumina powders obtained in each of the Examples and Comparative Examples were evaluated as follows.
The results are shown in Table 1. In Table 1, "-" means not measured.
＜バリ抑制＞
　得られた球状アルミナ粉末９０．１質量部と、ビフェニレンアラルキルフェノール型エポキシ樹脂（日本化薬株式会社製、商品名；ＮＣ－３０００、エポキシ当量２７５、軟化点５６℃）４．８質量部と、フェノール樹脂（フェノールアラルキル樹脂、明和化成株式会社製ＭＥＨＣ－７８００Ｓ）３．７質量部と、トリフェニルホスフィン（北興化学工業株式会社製：ＴＰＰ）０．１９質量部と、Ｎ－フェニル－３－アミノプロピルトリメトキシシラン信越化学工業株式会社製：ＫＢＭ－５７３）０．３５質量部とを、ヘンシェルミキサー（日本コークス工業社製「ＦＭ－２０Ｃ／Ｉ」）を用いて、常温、回転数２０００ｒｐｍの条件下で混合し、得られた混合物を、同方向噛み合い二軸押出混練機（スクリュー径Ｄ＝２５ｍｍ、Ｌ／Ｄ＝１０．２、パドル回転数５０～１２０ｒｐｍ、吐出量３．０ｋｇ／Ｈｒ、混練物温度９８～１００℃）で加熱混練して、樹脂組成物を得た。 <Burring prevention>
A mixture of 90.1 parts by mass of the obtained spherical alumina powder, 4.8 parts by mass of biphenylene aralkyl phenol type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name: NC-3000, epoxy equivalent 275, softening point 56° C.), 3.7 parts by mass of phenol resin (phenol aralkyl resin, manufactured by Meiwa Kasei Co., Ltd. MEHC-7800S), 0.19 parts by mass of triphenylphosphine (manufactured by Hokko Chemical Industry Co., Ltd.: TPP), and N-phenyl-3-aminopropyltrimethylamine was used. The mixture was mixed with 0.35 parts by mass of toxosilane (manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-573) using a Henschel mixer (manufactured by Nippon Coke and Engineering Co., Ltd., "FM-20C/I") at room temperature and at a rotation speed of 2000 rpm, and the resulting mixture was heated and kneaded using a co-rotating intermeshing twin-screw extruder kneader (screw diameter D=25 mm, L/D=10.2, paddle rotation speed 50 to 120 rpm, discharge rate 3.0 kg/Hr, kneaded product temperature 98 to 100° C.) to obtain a resin composition.
　得られた樹脂組成物について、２μｍ、５μｍ、１０μｍ、３０μｍのスリットを持つバリ測定用金型を用い、成形温度は１７５℃、成形圧力は７．４ＭＰａで成形した際にスリットに流れ出た樹脂をノギスで測定し、それぞれのスリットで測定された値を平均し、バリ長さ（μｍ）を求めた。
　バリ長さが２ｍｍ以下の場合、成形時のバリ発生を抑制できる（良）と評価し、２ｍｍを超える場合、成形時にバリが発生する恐れがある（不良）と評価した。 The obtained resin composition was molded using a burr measurement mold having slits of 2 μm, 5 μm, 10 μm, and 30 μm at a molding temperature of 175° C. and a molding pressure of 7.4 MPa. The amount of resin that flowed into the slits was measured with a vernier caliper, and the values measured for each slit were averaged to determine the burr length (μm).
When the burr length was 2 mm or less, it was evaluated as being able to suppress the generation of burrs during molding (good), and when it exceeded 2 mm, it was evaluated as being likely to generate burrs during molding (bad).
＜流動性＞
　上記で得られた樹脂組成物を使用し、スパイラルフロー金型を用い、ＥＭＭＩ－１－６６（Ｅｐｏｘｙ　Ｍｏｌｄｉｎｇ　Ｍａｔｅｒｉａｌ　Ｉｎｓｔｉｔｕｔｅ；Ｓｏｃｉｅｔｙ　ｏｆ　Ｐｌａｓｔｉｃ　Ｉｎｄｕｓｔｒｙ）に準拠して行った。金型温度は１７５℃、成形圧力７．４ＭＰａ、保圧時間９０秒とした。
　スパイラルフローが１５０ｃｍ以上であるものを良好とし、１５０ｃｍ未満であるものと不良として評価した。 <Liquidity>
The resin composition obtained above was used in a spiral flow mold in accordance with EMMI-1-66 (Epoxy Molding Material Institute; Society of Plastics Industry). The mold temperature was 175° C., the molding pressure was 7.4 MPa, and the pressure retention time was 90 seconds.
A spiral flow of 150 cm or more was evaluated as good, and a spiral flow of less than 150 cm was evaluated as poor.
＜熱伝導率＞
　上記で得られた樹脂組成物を使用し、直径２８ｍｍ、厚さ３ｍｍの円盤状サイズ穴を設けた金型に樹脂組成物を流し込み、脱気後１５０℃×２０分で成形した。得られた成形体について、得られた樹脂組成物について、熱伝導率測定装置（日立テクノロジーアンドサービス社製樹脂材料熱抵抗測定装置「ＴＲＭ－０４６ＲＨＨＴ」（商品名）を用い、ＡＳＴＭ　Ｄ５４７０に準拠した定常法で熱伝導率（Ｗ／ｍ・Ｋ）を測定した。樹脂組成物は幅１０ｍｍ×１０ｍｍに加工し、２Ｎの荷重をかけながら測定を実施した。
　熱伝導率（Ｗ／ｍ・Ｋ）＝成形体の厚さ（ｍ）／｛熱抵抗（℃／Ｗ）×伝熱面積（ｍ２）｝ <Thermal Conductivity>
The resin composition obtained above was poured into a mold having a disk-shaped hole with a diameter of 28 mm and a thickness of 3 mm, and molded at 150°C for 20 minutes after degassing. The thermal conductivity (W/m·K) of the obtained molded body was measured by a steady method in accordance with ASTM D5470 using a thermal conductivity measuring device (a resin material thermal resistance measuring device "TRM-046RHHT" (product name) manufactured by Hitachi Technology and Services Co., Ltd.). The resin composition was processed to a width of 10 mm x 10 mm, and measurements were performed while applying a load of 2 N.
Thermal conductivity (W/m·K)=thickness of molded body (m)/{thermal resistance (° C./W)×heat transfer area (m 2 )}
　実施例１～４の球状アルミナ粉末は、比較例１と比べて、樹脂組成物の成形時におけるバリ発生を抑制でき、また、樹脂成形材料の熱伝導性を高められる結果を示した。また、実施例１～４の球状アルミナ粉末は、樹脂成形材料に使用したときの流動性に優れる結果を示した。 Compared to Comparative Example 1, the spherical alumina powders of Examples 1 to 4 were able to suppress the generation of burrs during molding of the resin composition, and also showed results that could improve the thermal conductivity of the resin molding material. In addition, the spherical alumina powders of Examples 1 to 4 showed results that showed excellent flowability when used in the resin molding material.
　この出願は、２０２２年１２月１６日に出願された日本出願特願２０２２－２０１０２１号を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese Patent Application No. 2022-201021, filed on December 16, 2022, the disclosure of which is incorporated herein in its entirety.
１　バーナー
２　溶融炉
３　配管
４　サイクロン
５　配管
８　バグフィルター
９　ブロワー
１１　可燃ガス供給管
１２　助燃ガス供給管
１３　原料供給管
１００　溶射装置 Reference Signs List 1 burner 2 melting furnace 3 piping 4 cyclone 5 piping 8 bag filter 9 blower 11 combustible gas supply pipe 12 combustion support gas supply pipe 13 raw material supply pipe 100 thermal spraying device

Claims (6)

  1. 　湿式によるレーザー回折散乱法で測定される体積頻度粒度分布において、累積値が１０％となる粒子径をＤ１０、累積値が５０％となる粒子径をＤ５０、累積値が９７％となる粒子径をＤ９７としたとき、
    　（Ｄ９７－Ｄ１０）／Ｄ５０が、４．２以上２０．０以下である、球状アルミナ粉末。     In a volume frequency particle size distribution measured by a wet laser diffraction scattering method, the particle size at which the cumulative value is 10% is D10 , the particle size at which the cumulative value is 50% is D50 , and the particle size at which the cumulative value is 97% is D97 .
    A spherical alumina powder having (D 97 -D 10 )/D 50 of 4.2 or more and 20.0 or less.
  2. 　請求項１に記載の球状アルミナ粉末であって、
    　Ｄ９７／Ｄ５０が、５．０以上２０．０以下である、球状アルミナ粉末。     The spherical alumina powder according to claim 1,
    A spherical alumina powder having a D 97 /D 50 of 5.0 or more and 20.0 or less.
  3. 　請求項１又は２に記載の球状アルミナ粉末であって、
    　下記の手順に従って測定される、当該球状アルミナ粉末を含む評価用樹脂ワニスのチキソ指数が、０．１０以上０．８０以下である、球状アルミナ粉末。
    （手順）
    　当該球状アルミナ粉末を、含有量が８３質量％となるように、２５℃で液状のビスフェノールＦ型エポキシと混合して、上記の評価用樹脂ワニスを得る。
    　続いて、得られた評価用樹脂ワニスにおいて、レオメータを用いて、２５℃下、せん断速度２［１／ｓ］で測定したときの粘度（η１）、およびせん断速度２０［１／ｓ］で測定したときの粘度（η２０）を測定する。上記のチキソ指数を、η２０／η１に基づいて求める。     The spherical alumina powder according to claim 1 or 2,
    A spherical alumina powder, the thixotropy index of a resin varnish for evaluation containing the spherical alumina powder being 0.10 or more and 0.80 or less, as measured according to the following procedure.
    (procedure)
    The spherical alumina powder is mixed with bisphenol F type epoxy that is liquid at 25° C. so that the content is 83 mass %, to obtain the above-mentioned resin varnish for evaluation.
    Next, the viscosity (η 1 ) of the obtained resin varnish for evaluation is measured using a rheometer at a shear rate of 2 [1/s] and a shear rate of 20 [1/s] at 25 ° C. The thixotropic index is calculated based on η 20 /η 1 .
  4. 　請求項３に記載の球状アルミナ粉末であって、
    　前記樹脂組成物の試験サンプルにおけるせん断速度：２０［１／ｓ］時における粘度η２０が、１０Ｐａ・ｓ以上２００Ｐａ・ｓ以下である、球状アルミナ粉末。     The spherical alumina powder according to claim 3,
    A test sample of the resin composition has a viscosity η20 of 10 Pa·s or more and 200 Pa·s or less at a shear rate of 20 [1/s].
  5. 　請求項１または２に記載の球状アルミナ粉末であって、
    　下記の手順で測定される、ゆるめ嵩密度が、１．１０ｇ／ｃｍ３以上１．５０ｇ／ｃｍ３以下である、球状アルミナ粉末。
    （手順）
    　当該球状アルミナ粉末を、１分間に５～１０ｇの投入量で、高さ２５ｃｍから自然落下させ、１００ｃｍ３の測定用カップの内部に投入し、カップから溢れ出るまで続けて、山盛りカップを準備する。
    　続いて、山盛りカップについて、タッピングせずに、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、ゆるめ嵩密度（ｇ／ｃｍ３）を算出する。
    　一方、山盛りカップについて、上下方向に１８０回の条件（ストローク長２ｃｍ、１秒／回）でタッピングした後で、カップの上面に溢れた分をすり切った後、カップに充填された球状アルミナ粉末の質量（ｇ）を測定し、かため嵩密度（ｇ／ｃｍ３）を算出する。     The spherical alumina powder according to claim 1 or 2,
    A spherical alumina powder having a loose bulk density of 1.10 g/ cm3 or more and 1.50 g/ cm3 or less, as measured by the following procedure.
    (procedure)
    The spherical alumina powder is allowed to fall from a height of 25 cm at a rate of 5 to 10 g per minute into a 100 cm3 measuring cup, and the fall is continued until the powder overflows from the cup, to prepare a heaping cup.
    Next, for the heaping cup, the overflowing amount is leveled off without tapping, and then the mass (g) of the spherical alumina powder filled in the cup is measured to calculate the loose bulk density (g/cm 3 ).
    On the other hand, for a heaping cup, after tapping it up and down 180 times (stroke length 2 cm, 1 second/time), the overflowed powder was leveled off from the top of the cup, and the mass (g) of the spherical alumina powder filled in the cup was measured to calculate the compacted bulk density (g/ cm3 ).
  6. 　請求項５に記載の球状アルミナ粉末であって、
    　前記手順で測定される、ゆるめ嵩密度をＡ、かため嵩密度をＰとしたとき、
    　（（Ｐ－Ａ）／Ｐ）×１００に基づいて求められる圧縮度が、３５％以上５５％以下である、球状アルミナ粉末。      The spherical alumina powder according to claim 5,
    When the loose bulk density measured by the above procedure is A and the hard bulk density is P,
    A spherical alumina powder having a degree of compression calculated based on ((P−A)/P)×100 of 35% or more and 55% or less.
PCT/JP2023/045120 2022-12-16 2023-12-15 Spherical alumina powder WO2024128317A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022201021 2022-12-16
JP2022-201021 2022-12-16

Publications (1)

Publication Number Publication Date
WO2024128317A1 true WO2024128317A1 (en) 2024-06-20

Family

ID=91485880

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/045120 WO2024128317A1 (en) 2022-12-16 2023-12-15 Spherical alumina powder

Country Status (1)

Country Link
WO (1) WO2024128317A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018047871A1 (en) * 2016-09-09 2018-03-15 住友化学株式会社 Alumina powder, alumina slurry, alumina-containing coating layer, multilayer separation membrane and secondary battery
CN111302368A (en) * 2020-04-10 2020-06-19 洛阳中超新材料股份有限公司 α -alumina micropowder and preparation method and application thereof
WO2023013441A1 (en) * 2021-08-05 2023-02-09 株式会社トクヤマ Composition and filler mixture
JP2024021860A (en) * 2022-08-04 2024-02-16 住友化学株式会社 Almina powder, resin composition, and method of manufacturing almina powder

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018047871A1 (en) * 2016-09-09 2018-03-15 住友化学株式会社 Alumina powder, alumina slurry, alumina-containing coating layer, multilayer separation membrane and secondary battery
CN111302368A (en) * 2020-04-10 2020-06-19 洛阳中超新材料股份有限公司 α -alumina micropowder and preparation method and application thereof
WO2023013441A1 (en) * 2021-08-05 2023-02-09 株式会社トクヤマ Composition and filler mixture
JP2024021860A (en) * 2022-08-04 2024-02-16 住友化学株式会社 Almina powder, resin composition, and method of manufacturing almina powder

Similar Documents

Publication Publication Date Title
US20110046267A1 (en) Alumina powder, process for its production and resin composition employing it
JP7543395B2 (en) Alumina powder, resin composition, and heat dissipation part
JP5410245B2 (en) Spherical alumina powder, its production method and use.
WO2022202583A1 (en) Inorganic oxide powder, resin composition, and compression molded article
WO2024128317A1 (en) Spherical alumina powder
WO2024128321A1 (en) Powder of spherical alumina particles
WO2024128320A1 (en) Spherical alumina powder
WO2024128318A1 (en) Spherical alumina powder
WO2024128316A1 (en) Spherical alumina powder
JP3816052B2 (en) Method for producing spherical siliceous powder
WO2023153352A1 (en) Inorganic powder
JP6612919B2 (en) Amorphous silica powder, resin composition, and semiconductor encapsulant
WO2023153353A1 (en) Inorganic powder
WO2022239708A1 (en) Silica powder in which aggregation is reduced, resin composition, and semiconductor sealing material
WO2023153351A1 (en) Inorganic powder
KR20240144981A (en) Mineral Powder
TW202436231A (en) Spherical alumina powder
WO2022202584A1 (en) Inorganic oxide powder, resin composition, and compression-molded article
JP4313924B2 (en) Spherical silica powder and method for producing the same
TW202434526A (en) Spherical alumina powder
WO2023153357A1 (en) Spherical silica powder
KR20240144980A (en) Mineral Powder
KR20240144982A (en) Mineral Powder
WO2023153355A1 (en) Spherical silica powder
WO2023153356A1 (en) Spherical silica powder

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23903596

Country of ref document: EP

Kind code of ref document: A1