JP4244323B2 - Spherical inorganic hollow powder, method for producing the same, and resin composition - Google Patents

Description

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

  Small hollow glass spherical powder is lighter in specific gravity than non-hollow inorganic powder, has low dielectric properties, heat resistance, heat insulation, pressure resistance, impact resistance, electrical characteristics, dimensional stability, molding Has an effect of improving physical properties such as For this reason, for example, for the purpose of weight reduction, resin molded parts such as molding compounds such as automobiles, portable electronic devices and home appliances, putty and sealing materials, buoyancy materials for ships, synthetic wood, reinforced cement outer wall materials, lightweight outer wall materials It is used for artificial marble. On the other hand, since it has a low dielectric constant effect due to the form of hollow particles, it is expected to be used in fields where there is a need for a low dielectric constant, such as multilayer printed boards, wire coating materials, and semiconductor encapsulants. As described above, the fine hollow glass spherical powder has a wide range of uses, and accordingly, in recent years, further miniaturization of the hollow glass spherical powder, the emergence of inorganic oxide hollow powders other than glass, and the like have been strongly demanded. ing.

A typical conventional spherical inorganic hollow powder is a hollow glass spherical powder. The production method is a method in which fine powder in which a glass-forming component and a foaming agent component are supported on silica gel is fired in a furnace to obtain a fine hollow glass sphere (Patent Document 1). As the physical properties of the hollow glass spheres obtained by this method, it is shown that the particle density is about 0.3 g / cm ³ and the average particle diameter is about 70 μm. However, in such a production method, the foaming agent component is essential, the purity does not increase such as the foaming agent component remaining, and there is a limit to further refinement and hollowness.
Japanese Examined Patent Publication No. 4-37017

An object of the present invention is further miniaturized amorphous spherical silica hollow powder, and amorphous spherical silica hollow powder is particularly a higher hollow rate of the highly purified with finer than conventional products, their It is providing a manufacturing method and the resin composition containing it.

That is, according to the present invention, the average particle size is 0.5 to 8 μm , the average sphericity is 0.85 or more, the 50% breaking pressure is 10 MPa or more, and the average hollowness calculated from the density measured using the pycnometer method is 20 It is an amorphous spherical silica hollow powder characterized in that it is ˜70% by volume and the maximum particle size is within 5 times the average particle size . Furthermore, the amorphous spherical silica hollow powder preferably contains 98% by mass or more of the amorphous spherical silica hollow powder. The present invention also provides a resin composition comprising these amorphous spherical silica hollow powders.

Furthermore, the present invention is a high temperature formed by a burner having at least a quadruple tube part assembled in this order from the outside: a combustion gas supply pipe, a combustible gas supply pipe, a combustion gas supply pipe, and a silica raw material powder supply pipe. In the flame, a silica raw material powder having a specific surface area of 40 m ² / g or more and an average particle diameter of 10 μm or less is supplied from the silica raw material powder supply pipe, spheroidized and hollowed, and then collected. This is a method for producing a crystalline spherical silica hollow powder. In particular, the silica raw material powder is preferably a silica powder having a specific surface area of 200 m ² / g or more.

  According to the present invention, the above object can be achieved. For example, good moldability with a varnish viscosity of 1000 mPa · s or less, particularly 800 mPa · s or less, a thermal expansion coefficient of 30 ppm or less, particularly 20 ppm or less, flame retardancy of V-0, and a relative dielectric constant of 3.5 or less. In particular, it is possible to produce a resin molded body of 3.0 or less (25 ° C., 1 GHz).

The amorphous spherical silica hollow powder of the present invention has fine and high sphericity as particles. First, an average particle diameter is 0.5-8 micrometers as a volume-based average particle diameter. When the average particle size exceeds 8 μm, for example, when a resin molded product is used, the smoothness of the surface is impaired, which causes deterioration of appearance and deterioration starting from uneven portions, and an interlayer insulating layer for multilayer substrates. When used as a material or a filler for a resist material, it cannot be accommodated in a predetermined layer thickness, which may cause various problems such as short-circuiting of a conduction part. The lower limit of the average particle size is 0.5 μm or more from the viewpoints of miscibility with the resin, hand linkability as a powder, and the like. The maximum particle size is within 5 times the average particle size. The average 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 sphericity is 0.85 or more. If the average sphericity is less than 0.85, the mixing property with the resin and the fluidity of the resin composition are also difficult. The average sphericity is obtained by taking a particle image taken with a stereomicroscope (for example, Nikon model “SMZ-10”), a scanning electron microscope or the like into an image analyzer (for example, manufactured by Avionics, Japan) as follows. Can be measured. In addition to this method, from the roundness of individual particles quantitatively automatically measured by a particle image analyzer (for example, “FPIA-1000” manufactured by Sysmex Corporation), the formula, sphericity = (roundness) ² It can also be obtained by conversion.

That is, the projected area (A) and the perimeter (PM) of the particle are measured from the particle image. When the area of a perfect circle corresponding to the perimeter (PM) is (B), the roundness of the particle can be displayed as A / B. Therefore, assuming a perfect circle having the same peripheral length as the sample particle (PM), PM = 2πr and B = πr ² , so that B = π × (PM / 2π) ² , and each particle The sphericity can be calculated as sphericity = A / B = A × 4π / (PM) ² . The sphericity of 200 arbitrary particles thus obtained is obtained, and the average value is defined as the average sphericity.

The hollow powder as used in the present invention is defined as a powder having an average hollowness ratio measured by the following of 10% by volume (hereinafter referred to as vol%) or more. When the average hollowness is less than 10 vol%, the effects of light weight, heat insulation, and low dielectric properties, which are the characteristics of the hollow particles, are not sufficiently exhibited . Average hollow rate is 20~70vol%. When it exceeds 70 vol%, the shell thickness of the particles becomes thin, and there is a possibility that the particles are destroyed during handling of the powder or kneading with the resin.

That is, the average hollow ratio can be calculated from the ratio of the measured particle density to the theoretical density of the particles. For example, when the measured value of the density of the spherical silica hollow particles is 1.1 g / cm ³ , the average hollow ratio is calculated as 50% by dividing by the theoretical density of amorphous silica 2.2 g / cm ^3. Is done. The density can be measured using, for example, a pycnometer automatic powder particle true density measuring device (trade name “Auto True Densor MAT-7000”) manufactured by Seishin Enterprise Co., Ltd.

The 50% breaking pressure is desirably 10 MPa or more. If it is less than 10 MPa, there is a possibility that the number of particles that are destroyed when mixed with resin increases. Here, the 50% breaking pressure is defined as a pressure at which the average hollowness is halved by pressing the powder with a cold isostatic press (CIP) manufactured by Kobe Steel, for example.

As for the material of the amorphous spherical silica hollow powder, the amorphous silica is preferably 98% by mass or more. Amorphous silica, compared to other mineral oxides, strength, low thermal expansion, Ru excellent electrical insulating properties.

The amount of impurities can be measured by, for example, an X-ray fluorescence analyzer (XRF), an energy dispersive X-ray fluorescence analyzer (EDX), an atomic absorption photometer (AAS), a plasma emission spectrometer (ICP), or the like. In the present invention, the spherical inorganic hollow powder was heated and dissolved in a mixed solution of hydrogen fluoride and perchloric acid, diluted with pure water, and then measured using an atomic absorption photometer manufactured by Shimadzu Corporation.

The amorphous spherical silica hollow powder of the present invention was assembled in the order of the production method of the present invention, that is , an auxiliary combustion gas supply pipe, a combustible gas supply pipe, an auxiliary combustion gas supply pipe, and a silica raw material powder supply pipe from the outside . A high-temperature flame is formed by a burner having at least a quadruple tube portion, and a silica raw material powder having a specific surface area of 40 m ² / g or more is supplied from the silica raw material powder supply pipe to be spheroidized and hollowed, and then captured. Can be manufactured by the method of collecting.

Here, when the specific surface area of the silica raw material powder is less than 40 m ² / g, either or both of spheroidization and hollowing cannot be achieved. A preferred specific surface area is 50 m ² / g or more, particularly 100 m ² / g or more. An average particle diameter is 10 micrometers or less, and it is preferable that it is 0.1-8 micrometers.

The material of the silica raw material powder used in the present invention, electrical characteristics, chemical stability, dimensional stability, considering the moldability, amorphous silica is preferred, especially fine amorphous spherical silica Silica powder having a specific surface area of 200 m ² / g or more is optimal in view of easy availability of the hollow powder.

Silica raw material powder is supplied from the outside to the silica raw material powder supply of the burner having at least a quadruple tube part assembled in the order of auxiliary combustion gas supply pipe, combustible gas supply pipe, auxiliary combustion gas supply pipe, silica raw material powder supply pipe Supplied from a tube into a high temperature flame. Here, the meaning of the burner having at least a quadruple tube portion is one or more selected from a combustible gas supply tube, an auxiliary combustible gas supply tube, and a silica raw material powder supply tube adjacent to the quadruple tube portion. That is, it may be a burner in which two or more are arranged. The silica raw material powder is supplied by, for example, a dry method in which it is accompanied by one or more mixed gases selected from gases such as air, nitrogen, oxygen, argon, helium, and flammable gas, In addition, it can be carried out by a wet method in which it is dispersed in one or more mixed media selected from a medium such as a flammable liquid and an organic solvent, and is slurried and supplied. From the viewpoint of productivity, the dry method is preferred.

A high temperature flame can be formed by injecting each gas into the furnace from the burner's auxiliary combustion gas supply pipe, combustible gas supply pipe, and auxiliary combustion gas supply pipe. A combustible gas is injected from a combustible gas supply pipe sandwiched between auxiliary combustion gas supply pipes. As the combustible gas, for example, one kind or two or more kinds of mixed gases selected from hydrocarbon gases such as methane, ethane, acetylene, propane, butane, and propylene, and hydrogen gas are used. On the other hand, one or two types of auxiliary combustion gases selected from, for example, air and oxygen are injected from the auxiliary combustion gas supply pipe.

The furnace may be either a vertical furnace or a horizontal furnace, but from the viewpoint of suppressing adhesion of amorphous spherical silica hollow powder to the furnace, flame stability, and operational stability, the above quadruple tube portion is used. A vertical furnace having at least a burner provided at the top of the furnace and a lower part connected to a collection system is preferred. A dust collector is installed in the collection system, and is sucked and transported to the collection system together with combustion exhaust gas or air positively supplied from the lower part of the furnace by a blower provided on the exhaust side and collected. As a dust collector, a cyclone, an electric dust collector, a bag filter, etc. can be used, for example. Regarding the structure of such a vertical furnace, there are many known structures except for the burner structure, which can be used.

The average sphericity of the amorphous spherical silica hollow powder is mainly determined by controlling the temperature in the furnace by controlling the flow rate of the combustible gas, and the average particle size, average hollow ratio, 50% breaking pressure, and purity are mainly silica. Adjustment control is possible by the particle size, specific surface area, and purity of the raw material powder. Specifically, when the flow rate of the combustible gas is increased, the temperature in the reaction vessel is increased and the raw material is sufficiently heated, so that an amorphous spherical silica hollow powder having a high average sphericity can be obtained. However, if the flow rate of the flammable gas is excessively increased, the powder becomes overheated, and there is a tendency that bubbles are not enclosed during the heating spheroidization, so that care must be taken. The higher the specific surface area of the silica raw material powder, the easier it is to enclose air bubbles inside during the heating spheronization, and the higher the hollow ratio can be produced.

Next, the resin composition of the present invention will be described. The resin composition of the present invention preferably contains 1 to 97% by mass of the amorphous spherical silica hollow powder of the present invention.

Examples of the resin include epoxy resins, silicone resins, phenol resins, melamine resins, urea resins, unsaturated polyesters, fluororesins, BT resins, polyimides, polyamideimides, polyetherimides, and other polyamides, polybutylene terephthalates, polyethylene terephthalates, etc. Polyester, polyphenylene sulfide, wholly aromatic polyester, polysulfone, liquid crystal polymer, polyethersulfone, polycarbonate, maleimide modified resin, ABS resin, AAS (acrylonitrile-acrylic rubber / styrene) resin, AES (acrylonitrile / ethylene / propylene / diene rubber) One or two or more selected from resins such as (styrene) resin are used.

Among these, as the multilayer printed circuit board and the semiconductor sealing material, an epoxy resin having two or more epoxy groups in one molecule is preferable. Specific examples include phenol novolac type epoxy resins, orthocresol novolak type epoxy resins, epoxidized phenol and aldehyde novolak 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 novolak type epoxy resin, 1,6-dihydroxynaphthalene type epoxy resin, 2,7-dihydroxynaphthalene type epoxy resin, bishydroxybiphenyl type epoxy resin, and halo such as bromine to impart flame retardancy Epoxy resins obtained by introducing the emissions, and the like. In particular, from the viewpoint of moisture resistance and solder reflow resistance, orthocresol novolac type epoxy resins, bishydroxybiphenyl type epoxy resins, and naphthalene skeleton epoxy resins are suitable.

As the curing agent for the epoxy resin, for example, one or more selected from a novolak type resin, a polyparahydroxystyrene resin, phenols, acid anhydrides, aromatic amines and the like are used. As the novolak type resin, one or a mixture of two or more selected from the group of phenol, cresol, xylenol, resorcinol, chlorophenol, t-butylphenol, nonylphenol, isopropylphenol, octylphenol, etc. is used as formaldehyde, paraformaldehyde or paraxylene. In addition, novolak-type resins obtained by reaction under an oxidation catalyst are used, and as phenols, bisphenol compounds such as bisphenol A and bisphenol S, trifunctional phenols such as pyrogallol and phloroglucinol are used, As the acid anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, etc. are used, and as the aromatic amine, metaphenylene diamine, diaminodiphenylmethane, diaminodiphenyl. Such as vinyl sulfonic is used.

When the resin composition of the present invention is an epoxy resin composition, a curing accelerator can be blended in order to accelerate the reaction between the epoxy resin and the epoxy resin curing agent. As the curing accelerator, for example, one or more selected from 1,8-diazabicyclo (5,4,0) undecene-7, triphenylphosphine, benzyldimethylamine, 2-methylimidazole and the like are used.

If necessary, the resin composition of the present invention may contain a stress reducing agent, a silane coupling agent, a surface treatment agent, a flame retardant aid, a flame retardant, a colorant, a release agent, and the like. Examples of the stress-reducing agent include rubbery substances such as silicone rubber, polysulfide rubber, acrylic rubber, butadiene rubber, styrene block copolymer, and saturated elastomer, for example, amino silicone, epoxy silicone, A modified epoxy resin or a modified phenolic resin modified with alkoxysilicone or the like is used. Examples of the silane coupling agent include epoxy silanes such as γ-glycidoxypropyltrimethoxysilane and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, such as aminopropyltriethoxysilane, ureidopropyltriethoxysilane, An aminosilane such as N-phenylaminopropyltrimethoxysilane, a hydrophobic silane compound such as phenyltrimethoxysilane, methyltrimethoxysilane, or octadecyltrimethoxysilane, or mercaptosilane is used. Examples of surface treatment agents include Zr chelates, titanate coupling agents, and aluminum coupling agents. Examples of flame retardant aids include Sb ₂ O ₃ , Sb ₂ O ₄ , and Sb ₂ O _5. Examples of colorants such as halogenated epoxy resins and phosphorus compounds include carbon black, iron oxide, dyes, and pigments. As the release agent, for example, natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, waxes such as paraffin, and the like are used.

In particular, when high moisture resistance reliability and high temperature storage stability are required, addition of various ion trapping agents is effective. Examples of commercially available ion trapping agents include Kyowa Chemical Co., Ltd. trade names “DHF-4A”, “KW-2000”, “KW-2100”, and Toa Gosei Chemical Co., Ltd. trade names “IXE-600”.

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, etc., then cooling and pulverizing what is kneaded 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. For this purpose, a mixer such as a rough machine, a bead mill, three rolls, a stirring mixer 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 a silicone type, an acrylic type or a fluorine type.

The apparatus used in the examples is a burner 4 comprising a quadruple tube structure nozzle assembled in the order of an auxiliary combustion gas supply pipe A, an inflammable gas supply pipe, an auxiliary combustion gas supply pipe B, and a silica raw material powder supply pipe from the outside. The book is installed at the top of the vertical furnace, while the lower part of the furnace is connected to a collection system (bag filter), and the product (spherical inorganic hollow powder) is sucked and transported together with combustion exhaust gas by a blower. Collected with bag filter.

Examples 1 to 3 Reference Example 1 Comparative Examples 1 to 3
Per one burner, the air from the combustion supporting gas supply tube ^{A 30Nm 3 / Hr, 3~8Nm 3} / Hr of LPG from the combustible gas supply pipe, 5 to 25 nm ³ / Hr supplied oxygen from combustion supporting gas supply tube B While the high-temperature flame is formed, the silica powder shown in Table 1 is supplied from the burner silica raw material powder supply pipe to the center of the high-temperature flame at a rate of about 5 kg / Hr together with the carrier air 20-30 Nm ³ / Hr. The resulting product was collected from the bag filter. As a result, various amorphous spherical silica hollow powders were produced by changing the characteristics of the silica raw material powder and the supply amounts of LPG and oxygen. The particle diameter distribution (average particle diameter D50, maximum particle diameter D100), average sphericity, average hollowness, 50% breaking pressure, and purity are shown in Table 1.

In order to evaluate the characteristics of the obtained amorphous spherical silica hollow powder, 100 parts by mass of brominated bisphenol A type liquid epoxy resin, 4 parts by mass of dicyandiamide, 0.2 part by mass of 2-ethyl 4-methylimidazole were added to methyl ethyl ketone 200. After dissolving in parts by mass, 1 part by mass of 3-glycidoxypropyltrimethoxysilane and 50 parts by volume of amorphous spherical silica hollow powder are added to 100 parts by volume of the epoxy resin, and stirred for 10 minutes with a high-speed mixer. And varnish was manufactured.

After measuring the viscosity of the obtained varnish, the varnish was impregnated into a glass cloth, heated in an electric furnace at 150 ° C. for 5 minutes, and then cut to obtain a prepreg. Twelve prepregs were stacked, and a laminate was manufactured by heating and pressing for 150 minutes at a pressure of 4.5 MPa and a temperature of 185 ° C., and its thermal expansion coefficient, flame retardancy, and relative dielectric constant were measured. The results are shown in Table 1.

(1) Varnish viscosity Using an E-type viscometer manufactured by Tokimec Co., Ltd., it was measured under the conditions of a cone rotor of 3 ° R14, a temperature of 30 ° C, and a rotor rotational speed of 2.5 rpm.

(2) Coefficient of thermal expansion of laminate plate A test piece having a diameter of 5 mm and a height of 10 mm was cut out from the obtained laminate plate, and measured according to JIS K7197 standard using a thermomechanical analyzer (TMA) manufactured by Shimadzu Corporation. .

(3) Flame retardancy of laminated board From the obtained laminated board, a test piece of 12.7 mm x 127 mm x 1 mm was cut out and measured according to UL-94 standards.

(4) Relative dielectric constant of laminated plate A test piece having a diameter of 100 mm and a thickness of 2 mm was cut out from the obtained laminated plate, and measured according to JIS K6911 standard using a dielectric constant measuring device manufactured by Hewlett-Packard Company.

As is clear from the comparison between the examples and the comparative examples, according to the present invention, the moldability of varnish viscosity of 1000 mPa · s or less, particularly 800 mPa · s or less is improved, and the thermal expansion coefficient is 30 ppm or less, particularly 20 ppm or less. Further, a laminate having a flame retardancy of V-0 and a relative dielectric constant of 3.5 or less, particularly 3.0 or less, and an amorphous spherical silica hollow powder used therefor were obtained.

The amorphous spherical silica hollow powder of the present invention is a resin molded part such as molding compound for automobiles, portable electronic devices, home appliances, etc., as well as putty, sealing material, buoyancy material for ships, synthetic wood, reinforced cement outer wall Used as a filler for materials and lightweight outer wall materials. In addition, the resin composition of the present invention was formed by heat-molding one or a plurality of prepregs for a printed circuit board, for example, a prepreg for a printed circuit board or a prepreg obtained by impregnating and curing a glass woven fabric, glass nonwoven fabric, or other organic base material. It is used for manufacturing electronic parts, and further, wire covering materials, semiconductor encapsulants, varnishes and the like.

Claims (6)

The average particle size is 0.5 to 8 μm, the average sphericity is 0.85 or more, the 50% breaking pressure is 10 MPa or more, and the average hollowness calculated from the density measured using the pycnometer method is 20 to 70% by volume. An amorphous spherical silica hollow powder characterized by having a maximum particle size within 5 times the average particle size. 2. The amorphous spherical silica hollow powder according to claim 1, wherein the amorphous spherical silica hollow powder contains 98% by mass or more of the amorphous spherical silica hollow powder. Specific surface area in a high-temperature flame formed by a burner having at least a quadruple tube part assembled in the order of auxiliary combustion gas supply pipe, inflammable gas supply pipe, auxiliary combustion gas supply pipe, silica raw material powder supply pipe from the outside Amorphous spherical silica hollow, characterized in that a silica raw material powder having an average particle diameter of 40 m ² / g or more and an average particle size of 10 μm or less is supplied from the silica raw material powder supply pipe, spheroidized and hollowed, and then collected. Powder manufacturing method. The method for producing an amorphous spherical silica hollow powder according to claim 3, wherein the silica raw material powder is a silica powder having a specific surface area of 200 m ² / g or more. A resin composition comprising the amorphous spherical silica hollow powder according to claim 1 or 2. A laminate comprising the resin composition according to claim 5.