JP5519489B2 - Method for producing inorganic hollow powder and resin composition used therefor - Google Patents

Description

The present invention relates to a method for producing an inorganic hollow powder and a resin composition using the same.

  As a typical inorganic hollow powder, there is a fine hollow glass sphere. In general, these micro hollow glass spheres are called glass micro balloons and have a lighter specific gravity than non-hollow inorganic powders, making use of various characteristics such as heat resistance, heat insulation, impact resistance, and pressure resistance. By adding, it is used for weight reduction, heat insulation performance and dimensional stability. For example, for the purpose of weight reduction, it is used for resin molded parts such as molding compounds for portable electronic devices and automobiles, paint for moving bodies, members, various building materials, and the like.

On the other hand, with the advent of an advanced information society, communication devices such as satellite broadcasting and mobile phones tend to be digitized and high-speed signal processing. Wire covering materials and substrates used in these communication devices, or those In the peripheral resin members, lower dielectric constant and lower dielectric loss tangent are desired.
By the way, the above-mentioned micro hollow glass spherical body has a low dielectric constant effect due to the form of hollow particles, and therefore there is a need for a material having a low dielectric constant such as a multilayer printed board, a wire coating material, and a semiconductor sealing material. Use in is expected.

  Thus, although the hollow glass spherical body has a wide range of uses, in recent years, further refinement of the hollow glass spherical powder, the appearance of high-purity inorganic oxide hollow powder, and the like have been strongly demanded.

  Also, in high-frequency wiring boards that require low dielectric constant and low dielectric loss tangent, if there is an impedance discontinuity on the circuit pattern transmission line, waveform disturbance due to signal reflection at that location, malfunction, and operational efficiency Decrease. For this reason, it is important to match the characteristic impedance when designing the circuit pattern of the wiring board. For example, in the case of a strip line, this characteristic impedance is determined by the line width, the dielectric constant and thickness of the insulating layer, and the like.

As a method for producing a fine hollow glass sphere, a fine powder having a glass forming component and a foaming agent component supported on silica gel is fired in a furnace to obtain a fine hollow glass sphere (see Patent Document 1). . As physical properties of the micro hollow glass sphere obtained by this method, it is shown that the particle density is about 0.3 g / cm ³ and the average particle size is about 70 μm. However, in the micro hollow glass spheres obtained by such a production method, a hollowness sufficient to impart a lightening effect, a heat insulating effect, etc. can be obtained, but a foaming agent component is essential as a production method, Purity does not increase, such as foaming agent components remaining. Further, the average particle diameter is around 70 μm, and it cannot be used for applications in which the thickness of the composite material is regulated including applications for reducing the dielectric constant.

As a further method for producing a fine inorganic hollow powder, a fine silica hollow powder having a high specific surface area is fired in a furnace to obtain a fine inorganic hollow powder (see Patent Document 2 and Patent Document 3). As the physical properties of the fine inorganic hollow powder obtained by this method, it is shown that the average hollowness is about 20 to 85% by volume, but the distribution of the hollowness of the hollow particles is not described. When used as a substrate, there may be a difference in the dielectric constant of the insulating layer between the laminate with segregated particles with high hollowness and the laminate with segregated particles with low hollowness. Impedance was unclear.
Japanese Examined Patent Publication No. 4-37017 JP 2005-206436 A JP 2006-62902 A

The object of the present invention is to produce inorganic hollow powders that are further refined than conventional hollow glass spheres, especially inorganic hollow powders that are made of amorphous silica that is refined and has high purity and low segregation of hollow ratio. to provide a mETHODS and resin composition.

  That is, the present invention has the following gist.

(1) An amorphous silica raw material powder having a pore volume of 0.1 to 1.0 ml / g and a maximum particle size of 10 μm or less at a powder concentration of 50 to 500 g / Nm ³ and 0.1 to 2. By supplying from a raw material supply pipe having a donut-like structure having a slit width of 0 mm and hollowing with a flame, the hollow particles having a hollow ratio of 60 to 80% by volume are 70 to 90% by mass, and the hollow ratio is 0 to 0%. 20% by volume of hollow particles are each contained in an amount of 5% by mass or less, the maximum particle diameter of the contained hollow particles is 25 μm or less, the specific surface area determined by the BET method is 30 m ² / g or less, and the average sphericity is 0.85. The method for producing an inorganic hollow powder comprising amorphous silica having a SiO ₂ content of 99.0% by mass or more .
(2) The method for producing an amorphous silica hollow powder according to (1) , wherein the flame is a high temperature flame of 1700 to 2200 ° C. and a low temperature flame of 1000 to 1400 ° C.
(3) Amorphous silica raw material powder having a pore volume of 0.1 to 1.0 ml / g and a maximum particle size of 10 μm or less at a powder concentration of 50 to 500 g / Nm ³ and 0.1 to 2. It is supplied from a raw material supply pipe having a donut-like structure having a slit width of 0 mm, and is hollowed by a high temperature flame of 1700 to 2200 ° C. and a low temperature flame of 1000 to 1400 ° C., and the SiO ₂ content is 99.0% by mass or more. A method for producing an inorganic hollow powder comprising amorphous silica .
(4) A resin composition comprising an inorganic hollow powder made of amorphous silica obtained by the production method according to any one of (1) to (3) .

According to the present invention, an inorganic hollow powder made of amorphous silica further refined than a conventional hollow glass sphere (hereinafter also referred to as an inorganic hollow powder), in particular, refinement and high purity and hollow ratio. An inorganic hollow powder with little segregation can be produced , and the obtained inorganic hollow body is useful for producing electronic parts, electric wire coating materials, semiconductor encapsulating materials, varnishes and the like.

The inorganic hollow powder made of amorphous silica produced by the present invention (hereinafter also referred to as inorganic hollow powder) contains 60-100% by mass of hollow particle powder having a particle hollowness of 60-80% by volume. In addition, 5% by mass or less (including 0% by mass) of hollow particle powder having a particle hollow ratio of 0 to 20% by volume is contained. If the hollowness exceeds 80% by volume, the shell thickness of the particles becomes thin and the particle strength becomes weak, and the particles may be broken during handling of the powder or kneading with rubber or resin.
In addition, in the impedance characteristic, when the hollow particle having a particle hollow ratio of 60 to 80% by volume is less than 60% by mass, a uniform resin molded body is produced when segregation of the hollow particle for each hollow ratio occurs. Becomes difficult. When the hollow particle having a particle hollow ratio of 0 to 20% by volume exceeds 5% by mass, the effect of the low dielectric property which is a characteristic of the hollow particle is not sufficiently exhibited.
The inorganic hollow powder of the present invention preferably contains 70 to 90% by mass of a hollow particle powder having a particle hollow ratio of 60 to 80% by volume, and is a hollow particle having a particle hollow ratio of 0 to 20% by volume. It is preferable to contain 3% by mass or less (including 0% by mass) of the powder.

  The hollow particles in the inorganic hollow powder of the present invention have shells in the surface layer of the particles, and the inside of the particles has a hollow structure. Basically, it is single-pored and has a different structure from porous hollow particles. Porous hollow particles do not sufficiently exhibit the effect of low dielectric properties, which is a feature of the hollow particles of the present invention.

The hollow ratio can be defined as the content of closed cells in the particle, and can be calculated from the ratio of the measured value of the particle density to the theoretical density of the particle.
For example, when the measured density (B) of the hollow silica particles is the theoretical density (A) of the amorphous silica, the hollow ratio (C) is C = (A−B) / A × 100, Can be obtained from The density can be measured using, for example, a pycnometer automatic powder particle true specific gravity measuring instrument (trade name “Auto True Densor MAT-7000”) manufactured by Seishin Enterprise Co., Ltd.

The degree of hollowness of the hollow particles can also be measured from the relationship between the particles and the film thickness by a scanning electron microscope.
For example, in the case of spherical silica hollow particles having a particle diameter of 8 μm and a hollow ratio of 70% by volume, the portion corresponding to closed cells is 70% by volume, and thus the volume of the bubble part is 187.56 μm ³ and the radius is 3.55 μm. It becomes. Therefore, the thickness of the shell containing closed cells is calculated as 0.45 μm from the difference between the radius of the hollow particles and the radius of the closed cells.
The relationship between such particles and shell thickness is that the resin hollow product obtained by mixing and curing the inorganic hollow powder of the present invention with resin is cut and polished, and the inorganic hollow particles exposed on the polished surface are cut. The surface can be imaged with a scanning electron microscope, and can be determined by measuring the shell thickness of any 500 particles.

  Hollow ratio distribution is measured by stirring and dispersing / sedimentation of inorganic hollow powder in an aqueous sucrose solution with a specific gravity of 1.3. The suspended matter and sediment are collected, washed, dried and weighed, and less than 40% by volume. The distribution of is calculated. Next, the cross section of the sediment is observed with a scanning electron microscope, the hollow ratio is obtained from the particle diameter and film thickness, and the mass frequency of 20% by volume or less is calculated. The suspended matter is further stirred and dispersed and settled in an alcohol aqueous solution having a liquid specific gravity of 0.9, and the suspended matter and sediment are collected, washed, dried and weighed to calculate a distribution of 60% by volume or more and less. Furthermore, the cross section of the suspended matter is observed with a scanning electron microscope, the hollow ratio is obtained from the particle diameter and film thickness, and the mass frequency of 80% by volume or less is calculated.

  The maximum particle size of the inorganic hollow powder of the present invention is 25 μm or less, preferably 20 μm or less. When the maximum particle size exceeds 25 μm, for example, when a resin molded body is used, the smoothness of the surface is impaired, which causes deterioration of the appearance and deterioration starting from the uneven portion. When the maximum particle diameter exceeds 25 μm, when used as an interlayer insulating material for a multilayer substrate or a filler for a resist material, it cannot be accommodated in a predetermined layer thickness, and various problems such as short-circuiting and disconnection of a conductive part are caused. There is a risk of inviting. The maximum particle diameter can be measured, for example, using a laser diffraction scattering method particle size distribution measuring apparatus (trade name “LS-230”) manufactured by Beckman Coulter. The average particle size is not particularly limited, but is preferably about 1/5 times the maximum particle size.

The specific surface area of the inorganic hollow powder of the present invention is 30 m ² / g or less, preferably 20 m ² / g or less. When the specific surface area exceeds 30 m ² / g or more, for example, when the varnish is formed, the viscosity increases, and it may be difficult to perform high filling, and the moldability may be deteriorated. In addition, as the specific surface area increases, the water absorption also increases, and the moisture resistance reliability may decrease when resin molding is performed.

The average sphericity of the inorganic hollow powder of the present invention is 0.85 or more. If the average sphericity is less than 0.85, the mixing with the resin and the fluidity of the resin composition are problematic. Particularly preferably, the average sphericity is 0.90 or more.
The average sphericity is measured by measuring the projected area (A) and perimeter (PM) of a particle from a scanning electron micrograph, and assuming that the area of a perfect circle with respect to the perimeter (PM) is (B), the sphericity of the particle Is represented as A / B. Therefore, assuming a perfect circle having the same circumference as that of the sample particle (PM), PM = 2πr and B = πr ² , so that B = π × (PM / 2π) ² . The sphericity is calculated as sphericity = A / B = A × 4π / (PM) ² . The sphericity is measured for 100 particles, and the average value is taken as the average sphericity.

Examples of the material of the inorganic hollow powder include composite oxides containing silica as a constituent component . Among these, amorphous silica is preferable because it is excellent in strength, low thermal expansion, and low dielectric properties. The purity of the amorphous silica is preferably such that the content of silicon dioxide (SiO ₂ ) is 99.0% by mass or more. In the case of a complex oxide having two or more components, the component constituting the complex oxide is not an impurity.

The SiO ₂ content is measured by, for example, an energy dispersive X-ray fluorescence analyzer (EDX), an atomic absorption photometer (AAS), a plasma emission spectrometer (ICP), a fluorescent X-ray analyzer (XRF), or the like. In the present invention, the inorganic hollow powder is heated and dissolved in a mixed solution of hydrogen fluoride and perchloric acid (20: 1 volume ratio), diluted with pure water, and then an atomic absorption photometer (for example, Shimadzu Corporation). ).

  When the inorganic hollow powder of the present invention is amorphous silica, the amorphous ratio is preferably 100 to 99.0%. The amorphous ratio of amorphous silica is determined by X-ray diffraction analysis using a powder X-ray diffractometer (for example, RIGAKU (“Model Mini Flex”)) in the range of 2θ of CuKα ray of 26 ° to 27.5 °. For example, in the case of silica, crystalline silica has a main peak at 26.7 °, but there is no peak in amorphous silica. When silica is mixed, a peak height of 26.7 ° corresponding to the ratio of crystalline silica is obtained, so from the ratio of the X-ray intensity of the sample corresponding to the X-ray intensity of the standard sample of crystalline silica, The mixing ratio of crystalline silica is calculated, and the amorphous ratio is obtained from the formula, amorphous ratio (%) = (1-crystalline silica mixing ratio) × 100.

  The inorganic hollow powder of the present invention is preferably treated with a surface treatment agent such as a silane coupling agent. Usually, since the surface of the inorganic powder is hydrophilic, the dispersibility in a hydrophobic dispersion medium such as a resin or an organic solvent is not good. Therefore, when the surface is treated with a surface treatment agent, the dispersibility is improved. In addition, when treated with a surface treatment agent, adhesion to rubber or resin, peel strength, and the like are also improved. The amount of the surface treatment agent used is preferably 0.05 to 5 parts by mass and more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the inorganic hollow powder.

As the surface treatment agent, a silane coupling agent, an aluminum coupling agent, a titanate coupling agent, a Zr chelate, or the like can be used.
Examples of silane coupling agents include epoxy silanes such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; aminopropyltriethoxysilane, ureidopropyltriethoxy Aminosilanes such as silane and N-phenylaminopropyltrimethoxysilane; hydrophobic silane compounds such as phenyltrimethoxysilane, methyltrimethoxysilane and octadecyltrimethoxysilane; vinylsilanes such as vinyltriethoxysilane and vinyltrimethoxysilane; mercaptosilane Etc.

In the method for producing an inorganic hollow powder of the present invention, an inorganic raw material powder having a pore volume of 0.1 to 1.0 ml / g is mixed with a powder concentration of 50 to 500 g in a high temperature flame and a low temperature flame formed by a burner. This is a method of collecting after spheroidizing and hollowing by supplying at / Nm ³ .

Here, when the pore volume of the inorganic raw material powder exceeds 1.0 ml / g, spheroidization and / or hollowing cannot be achieved, resulting in porosity, and the pore volume is less than 0.1 ml / g. Then, hollowing cannot be achieved, and it becomes solid. A preferable pore volume is 0.2 to 0.8 ml / g.
The maximum particle size of the inorganic raw material powder is 10 μm or less. If it exceeds 10 μm, the particle size when hollowed out exceeds 25 μm, and the inorganic hollow powder of the present invention cannot be produced. A preferred maximum particle size is 1.0 to 8.0 μm.

If the powder concentration when supplying the inorganic raw material powder is less than 50 g / Nm ³ , the powder is partially overheated, so that hollowing is insufficient and hollow particles are hardly formed. If it is 500 g / Nm ³ or more, dispersion is insufficient and uniform heating cannot be achieved, and spheroidization and hollowing are insufficient, so that the inorganic hollow powder of the present invention cannot be produced. The powder concentration of the supply of the inorganic raw material powder is preferably 100 to 300 g / Nm ³ .

  The inorganic raw material powder is supplied from a raw material supply pipe separate from the burner. As a method for supporting the inorganic raw material powder on the supporting gas, for example, a known method such as supplying the inorganic raw material powder cut from the table feeder together with the supporting gas from the raw material supply pipe may be used. The inorganic raw material powder can be supported on one or both of a combustible gas and a combustion-supporting gas. As a result of the study by the present inventors, the method of supporting on any one of the gases is preferably the method of supporting on a combustion-supporting gas, and the object of the present invention is easily achieved.

  The raw material supply pipe of the present invention has a donut-like structure having a slit width of 0.1 to 2.0 mm. If the doughnut-shaped structure is not used, the distribution of the ejection speed becomes large at the wall surface portion and the center portion of the supply pipe. Although the velocity distribution can be suppressed by reducing the supply pipe diameter, the pressure loss is large and it is difficult to eject the inorganic raw material powder. Even if the slit width is less than 0.1 mm, the pressure loss is similarly large, and it is difficult to eject the inorganic raw material powder. When the slit width exceeds 2.0 mm, the jet velocity distribution becomes large, it is impossible to heat uniformly, the spheroidization / hollowing is insufficient, and the inorganic hollow powder of the present invention cannot be produced. The raw material supply pipe preferably has a donut-like structure having a slit width of 0.5 to 1.5 mm.

The high temperature flame and the low temperature flame are formed by supplying a combustible gas and a combustion supporting gas to each burner. Each burner is arranged in order from the inside to surround the raw material supply pipe, high temperature flame burner group, low temperature flame burner group with an angle to the raw material supply pipe side, and adjusting the angle of each burner group, the inorganic raw material The residence time of the powder in the flame can be controlled. Each burner group consists of 2-8. One burner group cannot uniformly heat all of the inorganic raw material powders. If the number of burner groups is nine or more, flame temperature control becomes difficult. Preferably, each burner group is 3-6.
As the combustible gas, for example, one or more mixed gases selected from the group consisting of hydrocarbon gases such as methane, ethane, acetylene, propane, butane, and propylene, and hydrogen gas are used. As the combustion-supporting gas, any gas having any component composition can be used as long as it contains oxygen.
The adjustment control of the flame temperature can be controlled by adjusting the ratio of the amount of combustible gas and the amount of combustible gas. It is also possible by adjusting and controlling the oxygen concentration in the combustion-supporting gas.

  The temperature of the high temperature flame is 1700-2200 ° C. If it is less than 1700 ° C., it is difficult to spheroidize. The temperature of the high temperature flame is preferably 1800 to 2000 ° C. The temperature of the low temperature flame is 1000 to 1400 ° C. If it is less than 1000 degreeC, the bubble expansion effect is not acquired and the inorganic hollow powder of this invention cannot be manufactured. If it exceeds 1400 ° C., the temperature close to the softening temperature of the inorganic raw material powder will continue, and bubbles will be degassed and it will be difficult to make them hollow. The temperature of the low temperature flame is preferably 1100 to 1300 ° C.

  The furnace for forming the flame may be either a vertical furnace or a horizontal furnace, but the above burner is placed at the top of the furnace from the viewpoint of suppressing adhesion of inorganic hollow powder to the furnace body, flame stability, operational stability, etc. A vertical furnace with a lower part connected to the collection system is preferred. A dust collector is installed in the collection system, and the produced inorganic hollow powder is sucked, transported and collected in the collection system by a blower provided on the exhaust side, and classified as necessary. Examples of the dust collector include a cyclone, an electric dust collector, and a bag filter. Regarding the manufacture of such a vertical furnace, there are many known examples except for the burner structure, which can be used.

The average sphericity of the inorganic hollow powder can be adjusted and controlled mainly by controlling the temperature of the high-temperature flame.
Further, the maximum particle size and specific surface area of the inorganic hollow powder can be adjusted and controlled mainly by the maximum particle size of the inorganic raw material powder and the powder concentration at the time of supplying the inorganic raw material powder.
The hollow ratio of the inorganic hollow powder can be adjusted and controlled by controlling the temperature of the low-temperature flame and the powder concentration at the time of supplying the inorganic raw material powder.
Specifically, when the flow rate of the combustible gas in the high-temperature flame burner is increased, the flame temperature is increased and the inorganic raw material powder is sufficiently heated, so that an inorganic hollow powder having a high average sphericity can be obtained. In addition, when the flame temperature of the low-temperature flame burner is increased, the expansion effect of the inorganic raw material powder is increased, and an inorganic hollow powder having a large hollow ratio is obtained. However, if the powder concentration at the time of supplying the inorganic raw material powder is too high, heating is performed. Distribution occurs in the state, and an inorganic hollow powder having a small hollow ratio is generated.

  The resin composition of the present invention is one in which the inorganic hollow powder of the present invention is contained in rubber and / or resin. The content of the inorganic hollow powder varies depending on the purpose. For example, it is 1 to 97% by mass, preferably 5 to 95% by mass.

  Examples of the rubber in the resin composition of the present invention include natural rubber, polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), polyisoprene rubber (IR), butyl rubber (IIR), and nitrile-butadiene copolymer. Examples thereof include polymer rubber (NBR).

  Examples of the resin in the resin composition of the present invention include epoxy resin, phenol resin, furan resin, unsaturated ester resin, xylene resin, silicone resin, melamine resin, urea resin, unsaturated polyester, fluororesin, BT resin (bismaleimide).・ Triazine resin), polyamide such as polyimide, polyamideimide, polyetherimide, polyester such as polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, wholly aromatic polyester, polysulfone, liquid crystal polymer, polyethersulfone, polycarbonate, maleimide modified resin, Examples include ABS resin, AAS (acrylonitrile-acrylic rubber / styrene) resin, AES (acrylonitrile / ethylene / propylene / diene rubber / styrene) resin, and the like.

  Examples of the resin for multilayer substrates in the resin composition of the present invention include polyimide resins such as modified polyimide resins; fluorine resins; low dielectric constant resins such as polyphenylene oxide, polyphenylene ether, and BT resin; polyimide, polyester, polyamide In particular, resins having good heat resistance and mechanical strength such as aromatic polyamide, polyamideimide, polyetherimide, etc. can be used.

  As the resin for a semiconductor sealing material in the resin composition of the present invention, an epoxy resin having two or more epoxy groups in one molecule is preferable. Specific examples include phenol novolac epoxy resins, orthocresol novolac epoxy resins, epoxidized phenol and aldehyde novolac resins, glycidyl ethers such as bisphenol A, bisphenol F and bisphenol S, phthalic acid, Glycidyl ester acid epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, alkyl-modified polyfunctional epoxy resin obtained by reaction of polybasic acid such as dimer acid and epochlorohydrin, β-naphthol novolac-type epoxy resin, 1,6-dihydroxynaphthalene-type epoxy resin, 2,7-dihydroxynaphthalene-type epoxy resin, bishydroxybiphenyl-type epoxy resin, and bromine and other halogen compounds to impart flame retardancy. An epoxy resin obtained by introducing a Gen. Among these, from the viewpoint of moisture resistance and solder reflow resistance, orthocresol novolac type epoxy resins, bishydroxybiphenyl type epoxy resins, epoxy resins having a naphthalene skeleton, and the like are preferable.

  When an epoxy resin is used as the resin, a curing agent is used, but the curing agent is not particularly limited as long as it is cured by reacting with the epoxy resin. For example, one or a mixture of two or more selected from the group consisting of phenol, cresol, xylenol, resorcinol, chlorophenol, t-butylphenol, nonylphenol, isopropylphenol, and octylphenol together with formaldehyde, paraformaldehyde or paraxylene Novolak-type resin obtained by reaction under the following conditions: polyparahydroxystyrene resin; bisphenol compounds such as bisphenol A and bisphenol S; trifunctional phenols such as pyrogallol and phloroglucinol; maleic anhydride, phthalic anhydride and pyromellitic anhydride Acid anhydrides such as acids; aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone;

  In the present invention, a curing accelerator can be blended to promote the reaction between the epoxy resin and the curing agent. Examples of the curing accelerator include 1,8-diazabicyclo (5,4,0) undecene-7, triphenylphosphine, benzyldimethylamine, 2-methylimidazole and the like.

The resin composition of the present invention may contain the following components as necessary.
That is, as a stress reducing agent, silicone rubber, polysulfide rubber, acrylic rubber, butadiene rubber, rubbery substances such as styrene block copolymers and saturated elastomers, various thermoplastic resins, resinous substances such as silicone resins, Examples thereof include resins obtained by modifying part or all of epoxy resins and phenol resins with amino silicone, epoxy silicone, alkoxy silicone, and the like.
Examples of the silane coupling agent include epoxy silanes such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; aminopropyltriethoxysilane, ureidopropyltriethoxysilane, N- And aminosilanes such as phenylaminopropyltrimethoxysilane; hydrophobic silane compounds such as phenyltrimethoxysilane, methyltrimethoxysilane, and octadecyltrimethoxysilane; mercaptosilane;
Examples of the surface treatment agent include Zr chelates, titanate coupling agents, and aluminum coupling agents.
Examples of the flame retardant aid include Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O _{5 and the} like.
Examples of the flame retardant include halogenated epoxy resins and phosphorus compounds.
Examples of the colorant include carbon black, iron oxide, dye, and pigment.
Furthermore, a release agent such as wax can be added. Specific examples include natural waxes, synthetic waxes, metal salts of linear fatty acid salts, acid amides, esters, paraffins and the like.

  Addition of various ion trapping agents is effective when moisture resistance reliability and high temperature storage stability are required. Specific examples of the ion trapping agent include Kyowa Chemical Co., Ltd. (trade names; “DHF-4A”, “KW-2000”, “KW-2100”, etc.) and Toa Gosei Chemical Industries Co., Ltd. (trade name; “IXE-”). 600 "etc.).

The resin composition of the present invention is obtained by, for example, blending a predetermined amount of each of the above materials with a blender, a Henschel mixer or the like, then kneading with a heating roll, kneader, uniaxial or biaxial extruder, etc. Can be manufactured.
In multilayer printed circuit board applications and paint applications, the above materials and organic solvents are mixed to make a varnish, but these materials can be mixed by mixing machines such as a raking machine, bead mill, three rolls, stirring mixer, etc. Is used. After forming the varnish, it is preferable to remove bubbles in the varnish by vacuum degassing.
In order to provide an antifoaming function and an antifoaming function, it is effective to add an antifoaming agent such as silicone, acrylic, or fluorine to the resin composition.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention should not be construed as being limited thereto.
The apparatus used for producing the inorganic hollow powder of the present invention is composed of three high-temperature flame burners inclined at 20 degrees with respect to the raw material supply pipe and three low-temperature flame burners inclined at 10 degrees with respect to the raw material supply pipe. It is installed at the top of the mold furnace and the lower part of the furnace is connected to a collection system (cyclone, bag filter).
The inorganic hollow powder was sucked and transported with a combustion exhaust gas by a blower and collected by a cyclone and a bag filter.

Examples 1-10 and Comparative Examples 1-8
A raw material supply pipe having a slit width of 0.1 to 1.5 mm was used. Hot flame burner groups, and one per LPG a 1 to 4 nm ³ / Hr burner to form a high-temperature flame of the oxygen supplied to the 3 to 15 nm ³ / Hr. Also, low-temperature flame burner group, and 0.5 to 3 nm ³ / Hr of LPG per one burner, to form a cold flame the oxygen-enriched air supplies and 1~10Nm ³ / Hr.
The inorganic raw material powder (silica) shown in Table 1 was supplied from a raw material supply pipe at a powder concentration of 50 to 500 g / Nm ³ and sprayed into a high temperature flame and a low temperature flame. Depending on the characteristics of the inorganic raw material powder and the LPG supply amount of each burner group, the support gas (oxygen, oxygen-enriched air) supply amount, and the powder concentration of the inorganic raw material powder, various inorganic hollows with different characteristics Powder (spherical hollow silica) was collected from the cyclone.
Content of hollow particles having a hollowness of 60 to 80% by volume and hollow particles having a hollowness of 0 to 20% by volume of particles of the collected inorganic hollow powder, maximum particle diameter, specific surface area, average sphericity, And the purity was measured according to the above. The results are shown in Table 1.
Moreover, as a result of measuring the amorphous ratio by the above method, it was confirmed that there was no peak and it was amorphous.
In addition, when surface-treating with a silane coupling agent, 0.5 mass part vinyltriethoxysilane was used with respect to 100 mass parts of inorganic hollow powder. A Henschel mixer was used for mixing, and the mixing time was 10 minutes.
In Tables 1 and 2, A hollow particles mean hollow particles having a hollow rate of 60 to 80% by volume, and B hollow particles mean hollow particles having a hollow rate of 0 to 20% by volume.
The measuring method of various physical properties is as follows.
(1) Pore volume The pore volume was determined by creating an adsorption isotherm of nitrogen at 7 8 K using an automatic specific surface area / pore distribution measuring device (manufactured by Micromeritics, TriStar 3000). The pore distribution curve was prepared by the BJH method.
(2) Maximum particle diameter The maximum particle diameter was measured using a laser diffraction scattering method particle size distribution measuring apparatus (trade name "LS-230") manufactured by Beckman Coulter.
(3) Content of silicon dioxide (SiO ₂ ) The content of silicon dioxide in the inorganic hollow powder was measured by the method described above.
(4) Hollow ratio of hollow particles The hollow ratio of the hollow particles was calculated from the ratio of the measured density of the particles to the theoretical density of the particles by the method described above. The density of the particles was measured by using a pycnometer method automatic granule true specific gravity measuring instrument (trade name “Auto True Denser MAT-7000”) manufactured by Seishin Enterprise Co., Ltd.
(5) Hollow ratio distribution of hollow particles The hollow ratio distribution of the hollow particles was measured by the method described above.
(6) Specific surface area The specific surface area measured the multipoint method specific surface area by BET method using the automatic specific surface area / pore distribution measuring apparatus (The product made by Micromeritics, TriStar3000).
(7) Average sphericity The average sphericity of the hollow particles was measured by the method described above.

  In order to evaluate the properties of the obtained inorganic hollow powder, 100 parts by mass of brominated bisphenol A type liquid epoxy resin, 4 parts by mass of dicyandiamide, and 0.2 parts by mass of 2-ethyl 4-methylimidazole were added to 200 parts by mass of methyl ethyl ketone. Dissolved. Thereafter, 1 part by mass of 3-glycidoxypropyltrimethoxysilane and 100 parts by volume of the inorganic hollow powder were added to 100 parts by volume of the epoxy resin, and stirred for 10 minutes with a high-speed mixer to produce a varnish.

After measuring the viscosity of the varnish, the glass cloth was impregnated with varnish, heated in an electric furnace at 150 ° C. for 5 minutes, and then cut to obtain a prepreg. This prepreg is piled up to the required thickness, and a laminate is manufactured by heating molding press for 200 minutes at a pressure (gauge pressure) of 5.0 MPa and a temperature of 180 ° C., and the coefficient of thermal expansion and flame retardancy are compared. The dielectric constant was measured. Thereafter, a microstrip line wiring board was prepared so that the characteristic impedance was 50Ω, and the variation in the characteristic impedance was measured. The results are shown in Table 1.
In addition, when using a varnish for a laminated board, it is preferable from a point which shape | molds a laminated board that varnish viscosity is 800 mPa * s or less, especially 700 mPa * s or less.

The measuring method of various physical properties is as follows.
(1) Varnish viscosity: Measured using an E-type viscometer manufactured by Tokimec Co., Ltd. under conditions of a cone rotor of 3 ° R14, a temperature of 30 ° C., and a rotor rotational speed of 2.5 rpm.
(2) Thermal expansion coefficient of laminated plate: A test piece having a diameter of 5 mm and a height of 10 mm was prepared from the laminated plate, and measured according to JIS K7197 standard using a thermomechanical analyzer (TMA) manufactured by Shimadzu Corporation.
(3) Flame retardancy of laminate: A test piece of 12.7 mm × 127 mm × 1 mm was prepared from the laminate and measured according to UL-94 standards.
(4) Relative dielectric constant of the laminate: A test piece having a diameter of 100 mm and a thickness of 2 mm was prepared from the laminate, and measured according to the JIS K6911 standard using a dielectric constant measuring device manufactured by Hewlett-Packard Company.
(5) Characteristic impedance: The substrate thickness (h) was 0.1 ± 0.02 mm and the conductor thickness (t) was 0.016 ± 0.002 mm so that the characteristic impedance would be 50Ω, and measured in (4). A microstrip line wiring board having a conductor width (W) of 0.223 to 0.181 ± 0.015 mm in accordance with the relative dielectric constant (εr) was prepared and measured using a network analyzer.

  As is clear from the comparison between the examples and the comparative examples, according to the examples of the present invention, the thermal expansion coefficient is 30 ppm or less, the flame retardancy is V-0, and the relative dielectric constant is 3.3 or less (25 ° C., 1 GHz). ) Can be produced. Furthermore, it is possible to manufacture a wiring board having a characteristic impedance variation of 5Ω or less when the specific impedance is set to 50Ω.

The inorganic hollow powder of the present invention is used as a filler for resin molded parts such as molding compounds for automobiles, portable electronic devices, home appliances, etc., as well as putty, sealing materials, lightweight outer wall materials and the like. Further, the resin composition of the present invention is impregnated into a glass woven fabric, glass nonwoven fabric, or other organic base material and cured. For example, a prepreg for a printed circuit board or one or a plurality of prepregs is thermoformed together with a copper foil or the like. In addition, it is used for manufacturing electronic parts, electric wire coating materials, semiconductor encapsulants, varnishes and the like.

The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2008-054370 filed on Mar. 5, 2008 are incorporated herein as the disclosure of the description of the present invention. Is.

Claims (4)

An inorganic raw material powder made of amorphous silica having a pore volume of 0.1 to 1.0 ml / g and a maximum particle size of 10 μm or less is used at a powder concentration of 50 to 500 g / Nm ³ and 0.1 to 2. By supplying from a raw material supply pipe having a donut-like structure having a slit width of 0 mm and hollowing with a flame, the hollow particles having a hollow ratio of 60 to 80% by volume are 70 to 90% by mass, and the hollow ratio is 0 to 0%. 20% by volume of hollow particles are each contained in an amount of 5% by mass or less, the maximum particle diameter of the contained hollow particles is 25 μm or less, the specific surface area determined by the BET method is 30 m ² / g or less, and the average sphericity is 0.85. der is, the production method of the inorganic hollow powder SiO ₂ content is 99.0 mass% or more amorphous silica or more. The method for producing an inorganic hollow powder according to claim 1 , wherein the flame is a high temperature flame of 1700 to 2200 ° C and a low temperature flame of 1000 to 1400 ° C. An amorphous silica raw material powder having a pore volume of 0.1 to 1.0 ml / g and a maximum particle size of 10 μm or less is slit at a powder concentration of 50 to 500 g / Nm ³ and 0.1 to 2.0 mm. It is supplied from a raw material supply pipe having a donut-like structure having a width, and is hollowed by a high temperature flame of 1700 to 2200 ° C. and a low temperature flame of 1000 to 1400 ° C., and an amorphous silica having a SiO ₂ content of 99.0% by mass or more A method for producing an inorganic hollow powder comprising : A resin composition comprising an inorganic hollow powder made of amorphous silica obtained by the production method according to any one of claims 1 to 3 .