JP2011195813A - Thermally expandable microsphere, hollow microparticle, method of manufacturing the same and application - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally expandable microsphere having a shape more nearly sphere and having a uniform shell thickness, wherein the presence of large resin particles at an inner side than a shell is suppressed, to provide the hollow microparticle obtained from the thermally expandable microsphere and to provide a method of manufacturing the hollow microparticle and application.SOLUTION: The thermally expandable microsphere is composed of the shell consisting of a thermoplastic resin and a foaming agent encapsulated in the shell and vaporized by heating, a repeating high temperature pressure resistant property of the hollow microparticle obtained by thermal expansion is 75% or more and a foaming agent retention before and after the thermal expansion is 80% or more. The hollow microparticle is obtained by thermally expanding the thermally expandable microsphere. The composition includes a granular material selected from the thermally expandable microsphere and the hollow microparticle and a substrate component. A formed body is obtained by forming the composition.

Description

  The present invention relates to thermally expandable microspheres, hollow fine particles, a method for producing the same, and applications.

Thermally expandable microspheres having a structure in which a thermoplastic resin is used as an outer shell and a foaming agent is enclosed in the outer shell are generally referred to as thermally expandable microcapsules. As the thermoplastic resin, a vinylidene chloride copolymer, an acrylonitrile copolymer, an acrylic copolymer, or the like is usually used. Moreover, hydrocarbons, such as isobutane and isopentane, are mainly used as a foaming agent (refer patent document 1).
For example, 80% by weight or more of nitrile monomer, 20% by weight or less of non-nitrile monomer, and a thermoplastic resin obtained from a component containing a crosslinking agent are used as heat-expandable microcapsules having high heat resistance. Patent Document 2 discloses a thermally expandable microcapsule used as a shell. The production method includes colloidal silica as a dispersion stabilizer (suspension agent), diethanolamine-adipic acid condensation product as an auxiliary stabilizer, and an aqueous dispersion medium containing a polymerization aid. This is a method for producing thermally expandable microcapsules by suspension polymerization of a polymerizable mixture containing a polymerizable monomer and a polymerization initiator.

The shape and structure of the thermally expandable microcapsule is ideally 1) the appearance is spherical, 2) the thickness of the outer shell is uniform, and 3) all the thermoplastic resin constitutes the outer shell, It is preferable that resin particles that do not constitute the outer shell, particularly large resin particles, are not present as much as possible inside the outer shell. However, in reality, it is very difficult to realize these three simultaneously. So far, 3) has been realized in thermally expandable microcapsules produced by suspension polymerization using peroxycarbonate as an initiator (see Patent Document 3). This thermally expandable microcapsule has an excellent thermal expansion property because the thickness of the outer shell is less likely to be smaller than the theoretical value.
However, there is no thermally expandable microcapsule that satisfies the above 1) to 3) at the same time, and in recent years its development has been strongly desired due to the demand for higher physical properties expected of the thermally expandable microcapsule.

US Pat. No. 3,615,972 JP-A-62-286534 International Publication No. 2007/046273 Pamphlet

  An object of the present invention is a thermally expandable microsphere having a shape closer to a sphere, having a uniform thickness of the outer shell, and suppressing the presence of large resin particles on the inner side of the outer shell, and its thermal expansion It is to provide hollow microparticles obtained from conductive microspheres, a method for producing the same, and uses thereof.

As a result of intensive studies, the present inventor has found that the above-described problems can be solved if the thermally expandable microspheres satisfy two specific physical properties at the same time, and have reached the present invention.
That is, the thermally expandable microsphere of the present invention is a thermally expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating. The high temperature pressure resistance of the hollow microparticles obtained in this way is 75% or more, and the foaming agent retention before and after the thermal expansion is 80% or more.

The thermoplastic resin is obtained by polymerizing a polymerizable component, and the polymerizable component is a nitrile monomer, a (meth) acrylic acid ester monomer, a carboxyl group-containing monomer, or a styrene monomer. And at least one monomer component selected from vinyl acetate, acrylamide monomers, maleimide monomers, and vinylidene chloride. The monomer component preferably includes a nitrile monomer and a (meth) acrylic acid ester monomer, and the nitrile monomer accounts for 80% by weight or more of the monomer component.
The method for producing thermally expandable microspheres of the present invention is a method for producing thermally expandable microspheres comprising an outer shell made of a thermoplastic resin and a foaming agent that is encapsulated in the shell and vaporizes when heated. ,

A polyalkylenimine having a molecular weight of 1000 or more having at least one structure in which an alkyl group substituted with a hydrophilic functional group selected from a carboxylic acid (salt) group and a phosphonic acid (salt) group is bonded to a nitrogen atom, and polyvinylpyrrolidone In the presence of the above, in the aqueous dispersion medium in which the oily mixture containing the polymerizable component and the foaming agent is dispersed, a polymerization initiator having an azo compound having a 10-hour half-life temperature of 63 ° C. or lower as an essential component is used. And a process for polymerizing the polymerizable component.
The azo compound is preferably 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) and / or 2,2′-azobis (2,4-dimethylvaleronitrile). The amount of the polyalkyleneimines is preferably 0.0001 to 1 part by weight with respect to 100 parts by weight of the polymerizable component.

The thermoplastic resin is obtained by polymerizing a polymerizable component, and the polymerizable component is a nitrile monomer, a (meth) acrylic acid ester monomer, a carboxyl group-containing monomer, or a styrene monomer. And at least one monomer component selected from vinyl acetate, acrylamide monomers, maleimide monomers, and vinylidene chloride. The monomer component preferably includes a nitrile monomer and a (meth) acrylic acid ester monomer, and the nitrile monomer accounts for 80% by weight or more of the monomer component.
The hollow fine particles of the present invention are obtained by heating and expanding the thermally expandable microspheres and / or the thermally expandable microspheres obtained by the production method.

It is preferable that the hollow fine particles are further composed of a fine particle filler attached to the outer surface of the outer shell. The method for producing the hollow fine particles includes a step of mixing the heat-expandable microspheres and / or the heat-expandable microspheres obtained by the production method and a fine particle filler, and the mixture obtained in the mixing step to the heat And heating the plastic resin to a temperature above the softening point of the plastic resin to expand the thermally expandable microspheres and attaching the fine particle filler to the outer surface of the outer shell.
The composition of the present invention comprises at least one granular material selected from the above-mentioned thermally expandable microspheres, the thermally expandable microspheres obtained by the above production method, the above hollow fine particles, and the hollow fine particles obtained by the above production method. And a base material component. It is preferable that the granular material is hollow fine particles, the content of the hollow fine particles is 0.1 to 10% by weight of the whole, and the base material component is an inorganic component. The inorganic component may be at least one inorganic material selected from cements, cordierite, and silicon carbide.
The molded product of the present invention is formed by molding the above composition.

The thermally expandable microspheres of the present invention satisfy the following 1) to 3).
1) It has a shape closer to a sphere.
2) The thickness of the outer shell is uniform.
3) The presence of large resin particles on the inner side of the outer shell is suppressed.
The method for producing the thermally expandable microspheres of the present invention has a shape that is closer to a sphere, the outer shell is uniform in thickness, and the thermal expansion in which large resin particles are suppressed on the inner side of the outer shell is suppressed. Active microspheres can be produced efficiently.

The hollow fine particles of the present invention are obtained by heating and expanding the heat-expandable microspheres of the present invention and / or the heat-expandable microspheres obtained by the production method of the present invention, so that they are lightweight and compressed in a high-temperature atmosphere. It is hard to crush.
The method for producing hollow fine particles of the present invention can efficiently produce hollow fine particles that are light in weight and are not easily crushed even when compressed in a high temperature atmosphere.

Since the composition of the present invention contains the thermally expandable microspheres and / or hollow fine particles, a lightweight molded product can be obtained by molding.
Since the molded product of the present invention is obtained by molding the above composition, it is lightweight.

It is an example of the schematic diagram of the thermally expansible microsphere of this invention. It is an example of the schematic diagram of the hollow microparticle A of this invention. It is the schematic of the foaming process part of the manufacturing apparatus used for the manufacturing method of a hollow microparticle for repeated high temperature pressure resistance measurement. 2 is an electron micrograph of thermally expandable microspheres obtained in Example 1. 2 is an electron micrograph of thermally expandable microspheres obtained in Comparative Example 1. 4 is an electron micrograph of thermally expandable microspheres obtained in Comparative Example 3.

[Thermal expandable microspheres and method for producing the same]
The thermally expandable microspheres of the present invention are composed of an outer shell made of a thermoplastic resin and a foaming agent that is contained in the outer shell and vaporizes when heated.
As shown in FIG. 1, the thermally expandable microsphere (1) of the present invention ideally has an outer shell (shell 2) made of a thermoplastic resin, and foam that is contained in the shell and is vaporized by heating. It has a core-shell structure composed of an agent (core, 3). Thermally expandable microspheres exhibit thermal expandability as a whole microsphere (property that the entire microsphere expands by heating). The thermoplastic resin, the polymerizable component that is polymerized to become a thermoplastic resin, the foaming agent, and the like are as described below.

In the heat-expandable microspheres of the present invention, the repeated fine high-temperature pressure resistance (measurement temperature: 70 ° C.) of the hollow fine particles obtained by thermally expanding the microspheres is 75% or more, preferably 77% or more, more preferably 79. % Or more, more preferably 80% or more, particularly preferably 82% or more, and most preferably 84% or more. The upper limit of the repeated high temperature pressure resistance of the hollow fine particles is 100%. When the high temperature pressure resistance of the hollow microparticles is less than 75%, the thermally expandable microsphere does not have a shape close to a sphere, the thickness of the outer shell is not uniform, and the resin is larger on the inner side than the outer shell. There are grains. In addition, when the high temperature pressure resistance of the hollow fine particles is less than 75%, the molded product such as a molded product or a coating film obtained from the thermally expandable microspheres as a raw material, in a high-temperature atmosphere of 60 ° C. or higher, light weight, Various physical properties such as porosity, heat insulating properties, design properties, and strength are lowered, and solvent resistance is lowered.
Repeated high-temperature pressure resistance is obtained by thermally expanding thermally expandable microspheres, and for hollow fine particles having a true specific gravity of (0.025 ± 0.001) g / cc, according to a measurement method described in detail in Examples, 70 Measured in degrees Celsius.

Repeated high temperature pressure resistance is part of the index of the degree of spherical shape of thermally expandable microspheres, the degree of uniformity of the outer shell thickness, and the degree of presence of large resin grains on the inner side of the outer shell. Physical properties for evaluating durability of hollow fine particles against stress generated when a base material component and hollow fine particles are mixed in a high temperature atmosphere of 60 ° C. or higher, or when a composition comprising the base material component and hollow fine particles is formed. Value. When hollow microparticles and / or heat-expandable microspheres, which are repeatedly high-temperature pressure-resistant, are mixed with a base material component at a high temperature, or consist of a base material component and hollow microparticles and / or heat-expandable microspheres. When the composition is molded or coated at a high temperature, durability against the generated stress is increased, and damage due to the stress is less likely to occur.
When the thermally expandable microsphere of the present invention is thermally expanded to obtain hollow fine particles, the foaming agent retention before and after thermal expansion is 80% or more, preferably 85% or more, more preferably 90% or more, More preferably, it is 93% or more, particularly preferably 95% or more, and most preferably 97% or more. The upper limit of the foaming agent retention before and after thermal expansion is 100%. When the foaming agent retention before and after thermal expansion is less than 80%, the thermally expandable microspheres do not have a shape close to a sphere, the thickness of the outer shell is not uniform, and the inner shell is larger than the outer shell. Resin grains are present. Moreover, when the foaming agent retention rate before and after thermal expansion is less than 80%, the hollow fine particles are deflated, and various physical properties such as lightness, porosity, heat insulating properties, design properties, and strength are deteriorated.

  In the thermally expandable microspheres of the present invention, the repeated high-temperature pressure resistance of the hollow fine particles obtained by thermal expansion is 75% or more, and the foaming agent retention before and after the thermal expansion is 80% or more, It is necessary to be satisfied at the same time. When both are satisfied, the thermally expandable microsphere has a shape closer to a sphere, the thickness of the outer shell is uniform, and the presence of large resin particles on the inner side of the outer shell can be suppressed. For the degree of spherical shape of the thermally expandable microspheres, the degree of uniformity of the outer shell thickness, and the extent of the presence of large resin particles on the inner side of the outer shell, an electron micrograph of a cross section of the thermally expandable microspheres was taken. It can be judged by observation.

In the thermally expandable microsphere of the present invention, the outer shell thickness is uniform. When an electron micrograph of the thermally expandable microsphere is observed, the ratio (D _max / D _min ) between the maximum outer shell thickness (D _max ) and the minimum outer shell thickness (D _min ) in the same cross section is preferably 1.6. Below, more preferably 1.4 or less, still more preferably 1.3 or less, particularly preferably 1.2 or less, and most preferably 1.1 or less. The lower limit value of D _max / D _min is 1.
In the thermally expandable microsphere of the present invention, the presence of large resin particles on the inner side than the outer shell is suppressed. When an electron micrograph of the heat-expandable microspheres is observed, the maximum diameter of the resin particles is preferably about 25% or less, more preferably about 20% or less, more preferably about 15% of the particle diameter of the heat-expandable microspheres. Hereinafter, it is particularly preferably about 13% or less, most preferably about 10% or less. The lower limit value of the maximum diameter of the resin particles is 0% of the particle diameter of the thermally expandable microsphere.

The thermally expandable microsphere preferably has the following physical properties.
The average particle diameter of the thermally expandable microsphere is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 80 μm, still more preferably 3 to 60 μm, and particularly preferably 5 to 50 μm.
The coefficient of variation CV of the particle size distribution of the heat-expandable microspheres is not particularly limited, but is preferably 45% or less, more preferably 40% or less, and particularly preferably 30% or less. The variation coefficient CV is calculated by the following calculation formulas (1) and (2).

(Wherein, s is the standard deviation of the particle size, <x> is an average particle size, x _i is the i-th particle diameter, n is the number of particles.)
The encapsulating rate of the foaming agent encapsulated in the thermally expandable microspheres is not particularly limited because it can be freely designed according to the application, but preferably 2 to 2 with respect to the weight of the thermally expandable microspheres. It is 60% by weight, more preferably 5 to 50% by weight, particularly preferably 8 to 45% by weight.

The thermally expandable microspheres of the present invention can be produced by a production method by suspension polymerization described in detail below, but are not limited to this production method. For example, the interfacial polymerization method, reverse phase emulsification method, emulsion weight It may be possible to manufacture it legally.
The method for producing thermally expandable microspheres of the present invention is a method for producing thermally expandable microspheres composed of an outer shell made of a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating. In this production method, in the presence of a polyalkyleneimine and polyvinylpyrrolidone, the polymerizable component and the foaming agent are dispersed in an aqueous dispersion medium in which the polymerizable component and the foaming agent are dispersed. A step of polymerization (polymerization step) is included.

The foaming agent is not particularly limited as long as it is a substance that is vaporized by heating. For example, propane, (iso) butane, (iso) pentane, (iso) hexane, (iso) heptane, (iso) octane, ( C3-C13 hydrocarbons such as (iso) nonane, (iso) decane, (iso) undecane, (iso) dodecane, (iso) tridecane; (iso) hexadecane, (iso) eicosane, etc. Hydrocarbons of 20 or less; pseudocumene, petroleum ether, hydrocarbons such as petroleum fractions such as normal paraffin and isoparaffin having an initial boiling point of 150 to 260 ° C and / or a distillation range of 70 to 360 ° C; their halides; hydro Fluorine-containing compounds such as fluoroethers; tetraalkylsilanes; compounds that thermally decompose by heating to generate gases Can. These foaming agents may be used alone or in combination of two or more. The foaming agent may be linear, branched or alicyclic, and is preferably aliphatic.
The polymerizable component is a component that becomes a thermoplastic resin that forms the outer shell of the thermally expandable microsphere by polymerization. The polymerizable component is a component which essentially includes a monomer component and may contain a crosslinking agent.

The monomer component generally includes a component called a (radical) polymerizable monomer having one polymerizable double bond.
The monomer component is not particularly limited. For example, nitrile monomers such as acrylonitrile, methacrylonitrile, and fumaronitrile; vinyl halide monomers such as vinyl chloride; vinylidene halides such as vinylidene chloride Monomers; Vinyl ester monomers such as vinyl acetate, vinyl propionate and vinyl butyrate; Carboxyl group-containing monomers such as (meth) acrylic acid, ethacrylic acid, crotonic acid and cinnamic acid; maleic acid and itacone Carboxylic anhydride monomers such as acid and fumaric acid; methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, Stearyl (meth) acrylate, phenyl (meth) acrylate, isobornyl (meth) (Meth) acrylic acid ester monomers such as acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate; methacrylic, substituted acrylamide, methacrylamide, substituted methacrylamide (meth) ) Acrylamide monomers; Maleimide monomers such as N-phenylmaleimide and N-cyclohexylmaleimide; Styrene monomers such as styrene and α-methylstyrene; Ethylene unsaturated monoolefins such as ethylene, propylene and isobutylene Monomers; vinyl ether monomers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone monomers such as vinyl methyl ketone; N-vinyl such as N-vinyl carbazole and N-vinyl pyrrolidone Monomer, vinyl naphthalene salt and the like. In addition, (meth) acryl means acryl or methacryl.

Monomer components include nitrile monomers, (meth) acrylic acid ester monomers, carboxyl group-containing monomers, styrene monomers, vinyl ester monomers, acrylamide monomers, maleimides It is preferable to further contain at least one selected from a system monomer and vinylidene chloride.
When the monomer component contains a nitrile monomer and a (meth) acrylic acid ester monomer, it is preferable from the viewpoints of retention of the foaming agent in the heat-expandable microsphere and heat resistance. In this case, the weight ratio of the nitrile monomer to the monomer component is not particularly limited, but is preferably 80% by weight or more, more preferably 85% by weight or more, particularly preferably 90% by weight or more, and most preferably Is 95% by weight or more.

The polymerizable component may contain a polymerizable monomer (crosslinking agent) having two or more polymerizable double bonds in addition to the monomer component. By polymerizing using a cross-linking agent, a decrease in the retention rate of the encapsulated foaming agent at the time of thermal expansion is suppressed, and thermal expansion can be effectively performed.
Although it does not specifically limit as a crosslinking agent, For example, aromatic divinyl compounds, such as divinylbenzene; Allyl methacrylate, triacryl formal, triallyl isocyanate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1 , 4-butanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, PEG # 200 di (meth) acrylate, PEG # 600 di (meth) acrylate, trimethylolpropane trimethacrylate, pentaerythrul Examples include di (meth) acrylate compounds such as tall tri (meth) acrylate, dipentaerythritol hexaacrylate, and 2-butyl-2-ethyl-1,3-propanediol diacrylate. These crosslinking agents may be used alone or in combination of two or more.

The amount of the crosslinking agent is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, and particularly preferably 0. 3 to 0.9 parts by weight.
Polymerization of the polymerizable component is performed using a polymerization initiator. The polymerization initiator is essentially composed of an azo compound having a 10-hour half-life temperature of 63 ° C. or less (hereinafter, sometimes referred to as “azo compound A” for simplicity) A soluble oil-soluble polymerization initiator is preferred.

The weight ratio of the azo compound A to the polymerization initiator is not particularly limited, but is preferably 50% by weight or more, more preferably 70% by weight or more, further preferably 80% by weight or more, and particularly preferably 90% by weight or more. Most preferably, it is 100% by weight. When the weight ratio of the azo compound A is less than 50% by weight, the resulting thermally expandable microspheres do not have a shape close to a sphere, the thickness of the outer shell is not uniform, and the inner side of the outer shell is not even. There may be large resin grains.
Examples of the azo compound A include 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) [10 hour half-life temperature: 30 ° C.], 2,2′-azobis (2,4-dimethyl). Valeronitrile) [10 hour half-life temperature: 51 ° C.] and the like. These azo compounds A may be used alone or in combination of two or more.

The 10-hour half-life temperature of the polymerization initiator is defined as a temperature at which 50% of the polymerization initiator is thermally decomposed in 10 hours when the polymerization initiator is charged in an inert solvent. In the present invention, the inert solvent is a value measured using toluene when the 10-hour half-life temperature is 105 ° C. or less, and ethylbenzene when the temperature exceeds 105 ° C. The 10-hour half-life temperature of the azo compound A shown above is listed in the oil-soluble azo polymerization initiator item of Chemical Products Home on the website of Wako Pure Chemical Industries, Ltd. as of February 10, 2010. It was the value that was. The 10-hour half-life temperature of 2,2′-azobis (2,4-dimethylvaleronitrile) is also listed on page 3 of an old catalog called V-65 by Wako Pure Chemical Industries, Ltd. (catalog number: 8201010). 31Y; obtained on September 12, 1983).
The polymerization initiator may contain a peroxide or an azo compound other than the azo compound A.

Examples of the peroxide include peroxydicarbonates such as diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate and di-2-ethylhexyl peroxydicarbonate, di-2-octyl peroxydicarbonate, Peroxydicarbonates such as dibenzylperoxydicarbonate; t-butylperoxypivalate, t-hexylperoxypivalate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-butylperoxy3 , 5,5-trimethylhexanoate, and the like.
Examples of the azo compound other than the azo compound A include 2,2′-azobisisobutyronitrile, dimethyl 2,2′-azobis (2-methylpropionate), 2,2′-azobis (2-methyl). Butyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide], 1-[(1-cyano- 1-methylethyl) azo] formamide, 2,2′-azobis (N-butyl-2-methylpropionamide), 2,2′-azobis (N-cyclohexyl-2-methylpropionamide), and the like. .

Although there is no limitation in particular about the quantity of a polymerization initiator, it is preferable in it being 0.3-10 weight part with respect to 100 weight part of said monomer components.
In the polymerization step, the oily mixture may further contain a chain transfer agent and the like.

The polymerization step is a step of polymerizing the polymerizable component in an aqueous dispersion medium in which an oily mixture is dispersed in the presence of a polyalkylenimine as a water-soluble compound and polyvinylpyrrolidone as a dispersion stabilizing aid. Polyalkyleneimines and dispersion stabilizing aids have high water solubility and are usually contained in an aqueous dispersion medium. In addition, the water solubility in this invention means the state which melt | dissolves 1g or more per 100g of water.
The aqueous dispersion medium is a medium mainly composed of water such as ion-exchanged water in which the oily mixture is dispersed, and may further contain an alcohol such as methanol, ethanol or propanol, or a hydrophilic organic solvent such as acetone. . The hydrophilicity in the present invention means that it can be arbitrarily mixed with water. Although there is no limitation in particular about the usage-amount of an aqueous dispersion medium, it is preferable to use 100-1000 weight part aqueous dispersion medium with respect to 100 weight part of polymeric components.

Polyalkyleneimines are alkyl groups substituted with a hydrophilic functional group selected from a carboxylic acid (salt) group and a phosphonic acid (salt) group (hereinafter referred to as “substituted alkyl group (A)” for the sake of simplicity). And at least one structure bonded to a nitrogen atom in the polyalkylenimines.
The polyalkyleneimines have, for example, an N-unsubstituted polyalkyleneimine obtained by polymerizing at least one alkyleneimine as a main skeleton, and a secondary amino group (—NH—) and primary in the main skeleton. A compound having at least one structure obtained by converting an amino group selected from an amino group (—NH ₂ ) into a tertiary amino group (—NR— or —NR ₂ ) and / or a secondary amino group (—NHR); It can also be expressed. Here, R is a substituted alkyl group (A).

The polyalkyleneimines may be linear (a state in which all alkyleneimine structural units are secondary amino groups) or branched (primary amino groups other than secondary amino groups in alkyleneimine structural units). Group and / or a tertiary amino group may be present). The polyalkyleneimines may have a main skeleton of a copolymer of a plurality of alkyleneimines.
The molecular weight (weight average molecular weight) of the polyalkyleneimines is usually 1000 or more, preferably 1000 to 1000000, more preferably 5000 to 500000, particularly preferably 8000 to 200000, and most preferably 10000 to 100,000.

The carboxylic acid (salt) group means a carboxylic acid group or a carboxylic acid group. The carboxylic acid group is a carboxyl group (—COOH), and the carboxylic acid group is a group in which the proton of the carboxyl group is replaced with a metal atom, a primary to quaternary amine group, an ammonium group (—NH ₄ ⁺ ), or the like.
A phosphonic acid (salt) group means a phosphonic acid group or a phosphonic acid group. The phosphonic acid group is —PO ₃ H ₂ , and the phosphonic acid group is a group in which at least one proton of the phosphonic group is replaced with a metal atom, a primary to quaternary amine group, an ammonium group (—NH ₄ ⁺ ), or the like. .

Examples of the metal atom include alkali metals such as lithium, sodium and potassium (Group 1 metals in the periodic table); alkaline earth metals such as beryllium, magnesium, calcium, strontium and barium (Group 2 metals in the periodic table); iron , Transition metals such as copper, manganese, zinc and cobalt. Of these metal atoms, sodium, potassium and the like are preferable.
As for the primary to quaternary amine group, the primary amine group is a group having a positive charge as a whole obtained by reacting a proton with a primary amine, and the secondary amine group is a proton having a secondary amine. The group obtained by reaction is a group having a +1 charge as a whole, and the tertiary amine group is a group having a +1 charge as a whole obtained by reacting a proton with a tertiary amine, and a quaternary amine group. Is a group having a +1 charge as a whole, wherein the proton of the tertiary amine group is substituted with a hydrocarbon group.

Examples of the primary to tertiary amine used as a raw material for the primary to tertiary amine group include (mono, di, or tri) alkylamines having 1 to 5 carbon atoms (for example, ethylamine, propylamine, etc.), and 2 to 10 carbon atoms. (Mono, di or tri) alkanolamine (eg, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, cyclohexyldiethanolamine, etc.), morpholine, cyclohexane having 5 to 20 carbon atoms There are alkylamines (for example, dicyclohexylamine), 3,3-dimethylpropanediamine, and the like.
Examples of quaternary amine groups include dodecyltrimethylammonium, cocoalkyltrimethylammonium, hexadecyltomethylammonium, beef tallow alkyltrimethylammonium, octadecyltrimethylammonium, behenyltrimethylammonium, cocoalkyldimethylbenzylammonium, tetradecyldimethylbenzammonium, octadecyl. Examples thereof include dimethylbenzylammonium, cocoalkylalkylammonium, tetradecylammonium, octadecylammonium, triethylmethylammonium, dioleyldimethylammonium, didecyldimethylammonium and the like.

The alkylene in the polyalkyleneimines is not particularly limited as long as it is a divalent saturated hydrocarbon group, but usually a divalent saturated hydrocarbon group having 1 to 10 carbon atoms (—C _n H _2n —, where n 1 to 10), and preferable examples include ethylene, propylene and butylene. The divalent saturated hydrocarbon group may be substituted with a substituent such as a hydroxyl group, an alkoxy group (for example, methoxy group, ethoxy group, etc.), a halogen atom (for example, fluorine atom, chlorine atom, bromine atom, etc.). Good.
Preferred examples of the substituted alkyl group (A) include a substituted methyl group, a substituted ethyl group, and a substituted propyl group.
Examples of the substituted alkyl group (A) include a group represented by the following general formula (1).

(Here, p is 1 to _10, C _{p H 2p} is be linear, may be branched, X is a carboxylic acid (salt) group or phosphonic acid (salt) group.)
In the above, p = 1 is a substituted methyl group, p = 2 is a substituted ethyl group, and p = 3 is a substituted propyl group.

Percentage of nitrogen atoms forming a structure in which the substituted alkyl group (A) is bonded to the nitrogen atom in the polyalkyleneimine (hereinafter sometimes referred to as “substitution rate of the substituted alkyl group (A)” for simplicity) .) Is preferably at least 10%, more preferably at least 20%, even more preferably at least 30%, particularly preferably at least 50%, most preferably at least 70% of the total nitrogen atoms of the polyalkyleneimines. When the substitution rate of the substituted alkyl group (A) is less than 10%, the effects of the present invention may not be obtained.
Examples of polyalkyleneimines include, for example, polyethyleneimines having at least one structure in which a substituted methyl group is bonded to a nitrogen atom, polypropyleneimines having at least one structure in which a substituted methyl group is bonded to a nitrogen atom, and substituted methyl groups Is a polybutyleneimine having at least one structure bonded to a nitrogen atom, a polyethyleneimine having at least one structure in which a substituted ethyl group is bonded to a nitrogen atom, and at least one structure in which a substituted ethyl group is bonded to a nitrogen atom Polypropylene imines having at least one structure in which a substituted ethyl group is bonded to a nitrogen atom, polyethylene imines having at least one structure in which a substituted propyl group is bonded to a nitrogen atom, and a substituted propyl group having a nitrogen atom Has at least one structure combined with Polypropylene imines, mention may be made of polybutylene imines such as substituted propyl group having at least one structure bonded to a nitrogen atom. These polyalkyleneimines may be used alone or in combination of two or more.

The amount of the polyalkyleneimines is not particularly limited, but is preferably 0.0001 to 1 part by weight, more preferably 0.0003 to 0.1 part by weight, particularly preferably 100 parts by weight of the polymerizable component. Is 0.001 to 0.05 parts by weight. If the amount of polyalkyleneimines is too small, the effects of polyalkyleneimines may not be sufficiently obtained. On the other hand, when the amount of polyalkyleneimines is too large, the polymerization rate may decrease, or the residual amount of the polymerizable component as a raw material may increase.
The aqueous dispersion medium may further contain a dispersion stabilizer and the like.

The dispersion stabilizer is not particularly limited, and examples thereof include tricalcium phosphate, magnesium pyrophosphate, calcium pyrophosphate obtained by a metathesis generation method, colloidal silica, alumina sol, and the like. These dispersion stabilizers may be used alone or in combination of two or more. The blending amount of the dispersion stabilizer is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymerizable component.
Polyvinyl pyrrolidone is a component used as a dispersion stabilizing aid, and is a water-soluble polymer, but also has high affinity with a polymerizable component. Polyvinylpyrrolidone may be a copolymer containing vinyl acetate or the like as a monomer component.

The amount of polyvinyl pyrrolidone is preferably 0.01 to 10 parts by weight, more preferably 0.05 to 5 parts by weight, particularly preferably 0.1 to 3 parts, most preferably 100 parts by weight of the polymerizable component. 0.2 to 1 part by weight.
The aqueous dispersion medium may further contain an electrolyte. Examples of the electrolyte include sodium chloride, magnesium chloride, calcium chloride, sodium sulfate, magnesium sulfate, ammonium sulfate, and sodium carbonate. These electrolytes may be used alone or in combination of two or more. Although there is no limitation in particular about content of an electrolyte, it is preferable to contain 0.1-50 weight part with respect to 100 weight part of aqueous dispersion media.

In the polymerization step, the oily mixture is emulsified and dispersed in an aqueous dispersion medium so that spherical oil droplets having a predetermined particle diameter are prepared.
Examples of the method for emulsifying and dispersing the oily mixture include, for example, a method of stirring with a homomixer (for example, manufactured by Tokushu Kika Kogyo Co., Ltd.) and the like, and a static dispersion device such as a static mixer (for example, manufactured by Noritake Engineering Co., Ltd.). And general dispersion methods such as a method using a film, a membrane emulsification method, and an ultrasonic dispersion method.

Next, suspension polymerization is started by heating the dispersion in which the oily mixture is dispersed as spherical oil droplets in the aqueous dispersion medium. During the polymerization reaction, it is preferable to stir the dispersion, and the stirring may be performed so gently as to prevent, for example, floating of the monomer and sedimentation of the thermally expandable microspheres after polymerization.
Although superposition | polymerization temperature is freely set by the kind of polymerization initiator, Preferably it is 30-100 degreeC, More preferably, it controls in the range of 40-90 degreeC. The time for maintaining the reaction temperature is preferably about 0.1 to 20 hours. Although there is no particular limitation on the initial polymerization pressure, the gauge pressure is in the range of 0 to 5.0 MPa, and more preferably in the range of 0.1 to 3.0 MPa.

[Hollow particles and method for producing the same]
The hollow fine particles are particles obtained by heating and expanding the heat-expandable microspheres described above and / or the heat-expandable microspheres obtained by the manufacturing method described above.
The hollow fine particles of the present invention are composed of an outer shell made of a thermoplastic resin and a hollow portion surrounded by the outer shell. The hollow fine particles are (almost) spherical and have a hollow portion corresponding to a large cavity inside. If the shape of the hollow fine particles is exemplified by familiar articles, a soft tennis ball can be mentioned.

The hollow part is (substantially) spherical and is in contact with the inner surface of the outer shell. The hollow portion is basically filled with a gas obtained by vaporizing the foaming agent, and a part of the foaming agent may be in a liquefied state. Further, all or part of the foaming agent may be replaced with other gas such as air. Usually, the hollow part is preferably one large hollow part, but there may be a plurality of hollow fine particles.
Although there is no limitation in particular about the average particle diameter of a hollow microparticle, Preferably it is 1-1000 micrometers, More preferably, it is 5-800 micrometers, Most preferably, it is 10-500 micrometers. Further, the coefficient of variation CV of the particle size distribution of the hollow fine particles is not particularly limited, but is preferably 45% or less, more preferably 40% or less, and particularly preferably 30% or less.

The true specific gravity of the hollow fine particles is not particularly limited, but is preferably 0.005 to 0.3, more preferably 0.010 to 0.25, and particularly preferably 0.015 to 0.20. When the true specific gravity of the hollow fine particles is smaller than 0.005, the durability may be lowered. On the other hand, when the true specific gravity of the hollow fine particles is larger than 0.3, the effect of lowering the specific gravity is reduced. Therefore, when the composition is prepared using the hollow fine particles, the amount added is large, which is uneconomical. There is.
As shown in FIG. 2, the hollow fine particles may be further composed of a fine particle filler adhered to the outer surface of the outer shell. Hereinafter, for the sake of simplicity, the hollow fine particles to which the fine particle filler is attached may be referred to as “hollow fine particles A”. The term “adhesion” as used herein refers to the state (6) in which the fine particle fillers (6 and 7) are simply adsorbed on the outer surface of the outer shell (5) of the hollow fine particles A (4). This means that the thermoplastic resin constituting the outer shell may be melted by heating, and the fine particle filler may sink into the outer surface of the outer shell of the hollow fine particle A and be fixed (7). The particle shape of the fine particle filler may be indefinite or spherical.

The true specific gravity of the hollow fine particles A is not particularly limited, but is preferably 0.01 to 0.5, more preferably 0.03 to 0.4, particularly preferably 0.05 to 0.35, most preferably Preferably it is 0.07-0.30. When the true specific gravity of the hollow fine particles A is smaller than 0.01, the durability may be lowered. On the other hand, when the true specific gravity of the hollow fine particles A is larger than 0.5, the effect of lowering the specific gravity is lowered. Therefore, when the composition is prepared using the hollow fine particles A, the amount added is large, which is uneconomical. There may be.
The average particle size of the fine particle filler is appropriately selected and is not particularly limited, but is preferably 0.001 to 30 μm, more preferably 0.005 to 25 μm, and particularly preferably 0.01 to 20 μm.

The ratio between the average particle diameter of the fine particle filler and the average particle diameter of the hollow fine particle A (average particle diameter of the fine particle filler / average particle diameter of the hollow fine particle A) is preferably 1 or less from the viewpoint of adhesion of the fine particle filler. More preferably, it is 0.8 or less, and particularly preferably 0.6 or less.
Various particles can be used as the fine particle filler, and any of inorganic and organic materials may be used. Examples of the shape of the fine particle main body include a spherical shape, a needle shape, and a plate shape.

Examples of inorganic substances constituting the fine particle filler include limestone (heavy calcium carbonate), quartz, silica (silica), wollastonite, gypsum, apatite, magnetite, zeolite, clay (montmorillonite, saponite, hectorite, beidellite, and steven. Minerals such as sight, nontronite, vermiculite, halloysite, talc, mica, mica, etc .; in the periodic table of elements, metal oxides of groups 1 to 16 (titanium oxide, zinc oxide, aluminum oxide, manganese oxide, Molybdenum oxide, tungsten oxide, vanadium oxide, tin oxide, iron oxide (including magnetic iron oxide, indium oxide, etc.), metal hydroxide (aluminum hydroxide, gold hydroxide, magnesium hydroxide, etc.), metal carbonate ( Calcium carbonate (light calcium carbonate), hydrogen carbonate Cium, sodium bicarbonate (bicarbonate), iron carbonate, etc., sulfate metal salts (aluminum sulfate, cobalt sulfate, sodium hydrogen sulfate, copper sulfate, nickel sulfate, barium sulfate, etc.), other metal salts (titanate (titanic acid) Barium, magnesium titanate, potassium titanate, etc.), borate (aluminum borate, zinc borate, etc.), phosphate (calcium phosphate, sodium phosphate, magnesium phosphate, etc.), nitrate (sodium nitrate, iron nitrate, lead nitrate, etc.) )) And the like.
Inorganic substances constituting the fine particle filler are also synthetic calcium carbonate, ferrite, zeolite, silver ion supported zeolite, zirconia, alum, lead zirconate titanate, alumina fiber, cement, zonotlite, silicon oxide (silica, silicate, glass, (Including glass fiber), silicon nitride, silicon carbide, silicon sulfide, carbon black, carbon nanotube, graphite, activated carbon, bamboo charcoal, charcoal, fullerene, and the like.

Organic substances constituting the fine particle filler are sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, nitrocellulose, hydroxypropyl cellulose, sodium alginate, polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, ( Examples include (meth) acrylic resins, polyamide resins, nylon resins, silicone resins, urethane resins, polyethylene resins, and fluorine resins.
The inorganic substance or organic substance constituting the fine particle filler may be treated with a surface treating agent such as fatty acid, resin acid, urethane compound, fatty acid ester, or may be untreated.

The method for producing the hollow fine particles is not particularly limited as long as it is a method for thermally expanding the heat-expandable microspheres, and may be either a dry heat expansion method or a wet heat expansion method.
Examples of the dry heating expansion method include a method described in Japanese Patent Application Laid-Open No. 2006-213930, particularly an internal injection method. As another dry heating expansion method, there is a method described in Japanese Patent Application Laid-Open No. 2006-96963. Examples of the wet heating expansion method include the method described in Japanese Patent Application Laid-Open No. 62-201231.

  As a method for producing the hollow fine particles A, for example, a step (mixing step) of mixing the thermally expandable microspheres and / or the thermally expandable microspheres obtained by the above production method with a fine particle filler, and the mixing step, A step of heating the obtained mixture to a temperature above the softening point of the thermoplastic resin to expand the thermally expandable microspheres and attaching the fine particle filler to the outer surface of the outer shell (attachment step) The manufacturing method containing these can be mentioned.

(Mixing process)
The mixing step is a step of mixing the thermally expandable microspheres and the fine particle filler.
The weight ratio of the fine particle filler and the thermally expandable microsphere in the mixing step (fine particle filler / thermally expandable microsphere) is not particularly limited, but is preferably 90 / 10-60 / 40, more preferably 85. / 15 to 65/35, particularly preferably 80/20 to 70/30. When the fine particle filler / heat-expandable microsphere (weight ratio) is larger than 90/10, the true specific gravity of the hollow fine particles A is increased, and the effect of lowering the specific gravity may be reduced. On the other hand, when the fine particle filler / heat-expandable microsphere (weight ratio) is smaller than 60/40, the true specific gravity of the hollow fine particles A becomes low, and handling such as dusting may deteriorate.

  There is no limitation in particular as an apparatus used for a mixing process, It can carry out using the apparatus provided with the very simple mechanism, such as a container and a stirring blade. Moreover, you may use the powder mixer which can perform a general rocking | swiveling or stirring. Examples of the powder mixer include a powder mixer that can perform rocking stirring or stirring, such as a ribbon mixer and a vertical screw mixer. In recent years, super mixers (manufactured by Kawata Co., Ltd.), high-speed mixers (manufactured by Fukae Co., Ltd.), and Newgram Machines (Seishin Co., Ltd.), which are efficient and multifunctional powder mixers by combining stirring devices Product), SV mixer (manufactured by Shinko Environmental Solution Co., Ltd.), and the like.

(Adhesion process)
In the attaching step, the mixture containing the thermally expandable microspheres and the fine particle filler obtained in the mixing step is heated to a temperature above the softening point of the thermoplastic resin constituting the outer shell of the thermally expandable microsphere. It is a process. In the attaching step, the thermally expandable microspheres are expanded and the fine particle filler is attached to the outer surface of the outer shell.
Heating may be performed using a general contact heat transfer type or direct heating type mixed drying apparatus. The function of the mixing type drying apparatus is not particularly limited, but it is preferable to be able to adjust the temperature and disperse and mix the raw materials, and optionally equipped with a decompression device and a cooling device for speeding up drying. Although there is no limitation in particular as an apparatus used for a heating, For example, a Ladige mixer (made by Matsubo Co., Ltd.), solid air (Hosokawa Micron Co., Ltd.), etc. can be mentioned.

  The temperature condition for heating depends on the type of the heat-expandable microsphere, but the optimum expansion temperature is preferable, preferably 60 to 250 ° C, more preferably 70 to 230 ° C, and still more preferably 80 to 220 ° C. is there.

[Application of thermally expandable microspheres and hollow fine particles]
The composition of the present invention comprises a base component and thermally expandable microspheres and / or hollow fine particles. Here, the heat-expandable microsphere means the heat-expandable microsphere described above and / or the heat-expandable microsphere obtained by the manufacturing method described above, and the hollow microparticle is described above. It means hollow fine particles and / or hollow fine particles obtained by the production method described above. Hereinafter, the thermally expandable microspheres and / or the hollow fine particles may be referred to as a granular material.
There is no limitation in particular as a base material component, What is necessary is just an inorganic component and / or an organic component.

The inorganic component is not particularly limited. For example, ordinary portland cement, early strength cement, alumina cement, blast furnace slag cement, fly ash cement, and the like; blast furnace slag, electric furnace oxidation slag, electric furnace reduction slag, etc. Slag; limes such as quicklime and slaked lime; titania, alumina, zirconia, silica, magnesia, zircon, barium zirconate, cordierite, lead titanate, barium titanate, mullite, zinc oxide, tin oxide, silicon carbide, silicon nitride And ceramics such as ferrite, and the like. These inorganic components may be used alone or in combination of two or more.
The inorganic component may be a component other than the inorganic components specifically shown above. For example, limestone (heavy calcium carbonate), quartz, silica (silica), wollastonite, gypsum, apatite, magnetite, zeolite, clay Minerals such as (montmorillonite, saponite, hectorite, beidellite, stevensite, nontronite, vermiculite, halloysite, talc, mica, mica, etc.); metals belonging to groups 1 to 16 in the periodic table of elements Metal oxide (titanium oxide, zinc oxide, aluminum oxide, manganese oxide, molybdenum oxide, tungsten oxide, vanadium oxide, tin oxide, iron oxide (including magnetic iron oxide), indium oxide, etc.), metal hydroxide ( Aluminum hydroxide, gold hydroxide, magnesium hydroxide, etc.), carbonic acid Metal salts (calcium carbonate (light calcium carbonate), calcium hydrogen carbonate, sodium hydrogen carbonate (bicarbonate), iron carbonate, etc.), metal sulfates (aluminum sulfate, cobalt sulfate, sodium hydrogen sulfate, copper sulfate, nickel sulfate, barium sulfate, etc.) ), Other metal salts (titanates (barium titanate, magnesium titanate, potassium titanate, etc.), borates (aluminum borate, zinc borate, etc.), phosphates (calcium phosphate, sodium phosphate, magnesium phosphate, etc.) ), Nitrates (sodium nitrate, iron nitrate, lead nitrate, etc.), and other metal compounds. These inorganic components may be used alone or in combination of two or more.

When the inorganic component is at least one inorganic material selected from cements, cordierite, and silicon carbide, it can be easily mixed and molded with hollow fine particles at room temperature, and can be formed by hydration condensation or firing. Since the material component is cured, it is preferable because it is easy to be made porous and lightweight by voids derived from hollow fine particles.
The organic component is not particularly limited. For example, rubbers such as natural rubber, butyl rubber, silicon rubber, ethylene-propylene-diene rubber (EPDM); thermosetting resins such as epoxy resin and phenol resin; polyethylene wax, paraffin Waxes such as wax; ethylene-vinyl acetate copolymer (EVA), ionomer, polyethylene, polypropylene, polyvinyl chloride (PVC), acrylic resin, thermoplastic polyurethane, acrylonitrile-styrene copolymer (AS resin), acrylonitrile- Butadiene-styrene copolymer (ABS resin), polystyrene (PS), polyamide resin (nylon 6, nylon 66, etc.), polycarbonate, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), poly Thermoplastic resins such as tar (POM) and polyphenylene sulfide (PPS); thermoplastic elastomers such as olefin elastomers and styrene elastomers; bioplastics such as polylactic acid (PLA), cellulose acetate, PBS, PHA, and starch resins; Sealing materials such as silicone, urethane, polysulfide, acrylic, silicone, polyisobutylene, butyl rubber, etc .; organic materials such as urethane, ethylene-vinyl acetate copolymer, vinyl chloride, and acrylic paint components These organic components may be used alone or in combination of two or more.

When these organic components are used as a base material component, there are generally some advantages such as a low melting temperature at the time of molding and a tendency to prevent modification when blended with hollow fine particles.
The composition of the present invention includes, as necessary, binders such as hydroxypropylmethylcellulose, methylcellulose, hydroxyethylcellulose, carboxylmethylcellulose, polyvinyl alcohol, polyethylene terephthalate, and the like; Further, it may contain a dispersant such as polyalcohol.

In the composition of the present invention, when the granular material is hollow fine particles and the substrate component is an inorganic component, the nonflammability and strength are high, and the heat resistance, durability, weather resistance, and the like are excellent. Furthermore, when the composition of the present invention contains hollow fine particles, the weight can be reduced. Here, the content of the hollow fine particles is not particularly limited, but is preferably 0.1 to 10% by weight, more preferably 0.15 to 5% by weight, and particularly preferably 0.2 to 2% by weight. If the content of the hollow fine particles is less than 0.1% by weight of the entire composition, the effect of reducing the weight may not be sufficiently obtained. On the other hand, if the content of the hollow fine particles is more than 10% by weight of the entire composition, the voids derived from the balloon occupying the composition will be too much, and the strength of the molded product will be reduced or it will be impossible to mold. Sometimes.
The composition of the present invention can be prepared by mixing a base material component with thermally expandable microspheres and / or hollow fine particles.

Examples of the use of the composition of the present invention include a molding composition, a coating composition, a clay composition, a fiber composition, an adhesive composition, and a powder composition.
The molded product of the present invention is obtained by molding this composition. Examples of the molded article of the present invention include molded articles such as molded articles and coating films. In the molded product of the present invention, various physical properties such as lightness, porosity, sound absorption, heat insulation / thermal conductivity, electrical conductivity, design properties, impact absorption, and strength are improved.

Examples will be specifically described below. The present invention is not limited to these examples.
With respect to the thermally expandable microspheres and hollow fine particles produced in the following Examples and Comparative Examples, the physical properties were measured in the following manner, and the performance was further evaluated.

[Measurement of average particle size and particle size distribution]
A laser diffraction particle size distribution analyzer (HEROS & RODOS manufactured by SYMPATEC) was used. The dispersion pressure of the dry dispersion unit was 5.0 bar, the degree of vacuum was 5.0 mbar, and measured by a dry measurement method, and the median diameter (D50 value) was defined as the average particle diameter.

[Measurement of moisture content of thermally expandable microspheres]
As a measuring apparatus, a Karl Fischer moisture meter (MKA-510N type, manufactured by Kyoto Electronics Industry Co., Ltd.) was used for measurement.

[Measurement of encapsulation rate of foaming agent enclosed in thermally expandable microspheres]
1.0 g of thermally expandable microspheres were placed in a stainless steel evaporation dish having a diameter of 80 mm and a depth of 15 mm, and the weight (W ₁ ) was measured. 30 ml of acetonitrile was added and dispersed uniformly, left at room temperature for 30 minutes, then heated at 120 ° C. for 2 hours, and the weight (W ₂ ) after drying was measured. The encapsulation rate of the foaming agent is calculated by the following formula.
Inclusion rate (% by weight) = (W ₁ −W ₂ ) (g) /1.0 (g) × 100− (water content) (% by weight)
(In the formula, the moisture content is measured by the above method.)

[Measurement of true specific gravity]
The true specific gravity of the thermally expandable microsphere and the hollow fine particles obtained by thermally expanding the microsphere was measured by the following measurement method.
The true specific gravity was measured by an immersion method (Archimedes method) using isopropyl alcohol in an atmosphere having an environmental temperature of 25 ° C. and a relative humidity of 50%.
Specifically, the volumetric flask having a capacity of 100 cc was emptied and dried, and the weight of the volumetric flask (WB ₁ ) was weighed. After the weighed volumetric flask was accurately filled with isopropyl alcohol to the meniscus, the weight (WB ₂ ) of the volumetric flask filled with 100 cc of isopropyl alcohol was weighed.

Further, the volumetric flask with a capacity of 100 cc was emptied and dried, and the weight of the volumetric flask (WS ₁ ) was weighed. The weighed volumetric flask was filled with about 50 cc of particles, and the weight (WS ₂ ) of the volumetric flask filled with the particles was weighed. Then, the weight (WS ₃ ) after accurately filling the meniscus with isopropyl alcohol so that bubbles do not enter into the volumetric flask filled with particles was weighed. Then, the obtained WB ₁ , WB ₂ , WS ₁ , WS ₂ and WS ₃ were introduced into the following equation, and the true specific gravity (d) of the particles was calculated.
d = {(WS ₂ −WS ₁ ) × (WB ₂ −WB ₁ ) / 100} / {(WB ₂ −WB ₁ ) − (WS ₃ −WS ₂ )}
In the above, the true specific gravity of each was calculated using thermally expandable microspheres or hollow fine particles as particles.

(Repeated high temperature pressure resistance)
As described above, the internal injection method described in Japanese Patent Application Laid-Open No. 2006-213930 was adopted as a method for producing hollow fine particles used for repeated high-temperature pressure resistance measurements. Specifically, using the manufacturing apparatus provided with the foaming process part shown in FIG. The hollow fine particles obtained were then repeatedly measured for high temperature pressure resistance by the following method.

(Explanation of foaming process part)
This foaming process section has a dispersion nozzle (11) at the outlet and a gas introduction pipe (not shown in the number) arranged in the center, and a collision plate (12) installed downstream of the dispersion nozzle (11). And an overheating prevention cylinder (10) disposed around the gas introduction pipe with a space therebetween, and a hot air nozzle (8) disposed around the overheating prevention cylinder (10) with a space therebetween. In this foaming process section, a gas fluid (13) containing thermally expandable microspheres is caused to flow in the direction of the arrow in the gas introduction tube, and in the space formed between the gas introduction tube and the overheating prevention cylinder (10). The gas flow (14) for improving the dispersibility of the thermally expandable microspheres and preventing the overheating of the gas introduction pipe and the collision plate is flowed in the direction of the arrow, and further, the overheating prevention cylinder (10) and the hot air nozzle In the space formed between (8), a hot air flow for thermal expansion flows in the direction of the arrow. Here, the hot air flow (15), the gas fluid (13), and the gas flow (14) are usually flows in the same direction. A refrigerant flow (9) flows in the direction of the arrow inside the overheating prevention cylinder (10) for cooling.

(Manufacturing equipment operation)
In the jetting process, the gaseous fluid (13) containing the thermally expandable microspheres is flowed through a gas introduction pipe provided with a dispersion nozzle (11) at the outlet and installed inside the hot air flow (15), and the gaseous fluid (13). From the dispersion nozzle (11).
In the dispersion step, the gas fluid (13) is caused to collide with the collision plate (12) installed downstream of the dispersion nozzle (11), so that the thermally expandable microspheres are uniformly dispersed in the hot air flow (15). To be operated. Here, the gaseous fluid (13) exiting from the dispersion nozzle (11) is guided toward the collision plate (12) together with the gas flow (14) and collides with it.
In the expansion step, the dispersed thermally expandable microspheres are heated and expanded above the expansion start temperature in the hot air flow (15). Thereafter, the obtained hollow fine particles are collected by passing them through a cooling part.

(Method for setting manufacturing conditions for hollow fine particles)
First, parameters such as the supply amount of the heat-expandable microspheres that are raw materials, the flow rate of hot air and the amount of raw material dispersed gas are fixed, and the temperature of the hot air flow (hereinafter sometimes referred to as “hot air temperature”) is changed. . Next, while changing the hot air temperature stepwise and fixing other parameters constant, the thermally expandable microspheres were expanded at each temperature, and the true specific gravity of the obtained microspheres was measured, and the hot air temperature ( A graph in which the relationship between the x axis) and the true specific gravity (y axis) is plotted is created.
When producing expanded microspheres having a desired true specific gravity ((0.025 ± 0.001) g / cc), the hot air temperature corresponding to the desired true specific gravity in the above graph is set. In this way, expansion conditions are controlled, and hollow fine particles having a true specific gravity of (0.025 ± 0.001) g / cc are produced.

(Repeated high temperature pressure resistance measurement)
2.00 mg of the hollow fine particles obtained above are put in an aluminum cup having a diameter of 6 mm (inner diameter 5.65 mm) and a depth of 4.8 mm, and an aluminum lid having a diameter of 5.6 mm and a thickness of 0.1 mm is placed on the hollow fine particle layer. Use the sample as a sample. Next, using a DMA (DMAQ800 type, manufactured by TA instruments), the height of the hollow fine particle layer in a state in which a force of 2.5 N was applied to the sample from the top of the aluminum lid with a pressurizer in an environment of 70 ° C. the L ₁ is measured. Then, after pressing the hollow fine particle layer from 2.5 N to 18 N at a speed of 10 N / min and then depressurizing from 18 N to 2.5 N at a speed of 10 N / min, the operation was repeated 8 times, and then the aluminum cap was pressed with the pressurizer. measuring the height L ₂ of the hollow fine particle layer in a state where the upper a force of 2.5 N. Then, as shown in the following formula, the ratio of the measured height L ₁ and L _{2 of} the hollow fine particle layer is repeatedly defined as high temperature pressure resistance.
Repeated high temperature pressure resistance (%) = (L ₂ / L ₁ ) × 100

[Foaming agent retention before and after thermal expansion]
The foaming agent retention before and after thermal expansion is the ratio between the encapsulation rate (G ₁ ) of the foaming agent encapsulated in the thermally expandable microspheres and the encapsulation rate (G ₂ ) of the foaming agent encapsulated in the hollow fine particles. Is calculated by the following equation.
Foaming agent retention (%) = G ₂ / G ₁ × 100

[Example 1]
In 600 g of ion-exchanged water, 80 g of colloidal silica having an active silica content of 20% by weight, 1 g of polyvinylpyrrolidone and polyethyleneimines (substituted alkyl group: —CH ₂ COONa, substitution rate: 80%, weight average molecular weight: 50,000) After adding 1 g, the pH of the obtained mixture was adjusted to 2.8 to 3.2 to prepare an aqueous dispersion medium.
Separately, 150 g of acrylonitrile, 105 g of methacrylonitrile, 13 g of isobornyl methacrylate, 1 g of trimethylolpropane trimethacrylate, 35 g of isobutane as a blowing agent, 25 g of isopentane, and 2,2′-azobis (2,4-dimethylvalero) (Nitrile) 3 g was mixed to prepare an oily mixture. The aqueous dispersion medium and the oily mixture were mixed, and the obtained mixed solution was dispersed for 5 minutes at a rotation speed of 8000 rpm with a homomixer (TK homomixer manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a suspension. The suspension was transferred to a 1.5 liter pressurized reactor and purged with nitrogen, then the initial reaction pressure was 0.5 MPa, and the polymerization reaction was carried out for 20 hours at a polymerization temperature of 60 ° C. while stirring at 80 rpm. The slurry state during the polymerization reaction was determined according to the following evaluation criteria, and the results are shown in Table 1. After polymerization, the polymerization product was filtered and dried to obtain thermally expandable microspheres. The physical properties were evaluated and are shown in Table 1.

The obtained heat-expandable microspheres were thermally expanded according to the above repeated high-temperature pressure resistance measurement method to obtain hollow fine particles. The hollow fine particles were repeatedly measured for high temperature pressure resistance and foaming agent retention before and after thermal expansion.
Further, in order to evaluate the shape of the obtained thermally expandable microspheres, 5 g of an epoxy adhesive (trade name Araldite, manufactured by Nichiban Co., Ltd.) and 50 g of thermally expandable microspheres were mixed and cured. The obtained cured product was cut to prepare a sample. A typical example of observing the cut surface of the sample and showing a cross section of the thermally expandable microsphere is obtained by using a scanning electron microscope (manufactured by Keyence Corporation, VE-8800) with an acceleration voltage of 20 kV and a magnification of 5000 times. Shot under the conditions of The obtained electron micrograph is shown in FIG. By visually observing FIG. 4, the shape of the thermally expandable microsphere (spherical degree, degree of uniformity of outer shell thickness, degree of presence of large resin particles on the inner side of the outer shell) is shown below. The results were shown in Table 1.

[Evaluation of slurry state during polymerization reaction]
A: No scale etc.
○: Some small scales are generated.
Δ: There is a large scale, and some aggregation occurs.
X: Aggregation or solidification.

[Evaluation of the shape of thermally expandable microspheres]
A: A shape close to a sphere is shown. Uniform outer shell thickness. There are no large resin grains on the inner side of the outer shell.
○: Not spherical. The outer shell thickness is uniform. There are no large resin grains on the inner side of the outer shell.
Δ: Not spherical. Outer shell thickness is uneven. There are no large resin grains on the inner side of the outer shell.
X: Not spherical. Outer shell thickness is uneven. There are large resin grains on the inner side of the outer shell.

[Examples 2 to 9 and Comparative Examples 1 to 9]
In Examples 2 to 9 and Comparative Examples 1 to 9, polymerization was carried out in the same manner as in Example 1 except that the reaction conditions in Example 1 were changed as shown in Tables 1 and 2, respectively. And hollow fine particles were obtained. Furthermore, the physical properties were evaluated and are shown in Tables 1 and 2.
For Comparative Example 1 and Comparative Example 3, electron micrographs taken in the same manner as in Example 1 are shown in FIGS. 5 and 6, respectively.

In FIG. 5 (Comparative Example 1) and FIG. 6 (Comparative Example 3), compared with FIG. 4 (Example 1), it is far from a spherical shape and has a considerably complicated shape.
Also, the thickness of the outer shell is not uniform. In FIG. 4, the maximum outer shell thickness / minimum outer shell thickness (D _max / D _min ) in the same cross section is about 1.25, whereas in FIGS. 5 and 6, about 2 and about 1 respectively. .7.
In FIG. 4, the maximum diameter of the resin particles is about 15% or less of the particle diameter of the heat-expandable microsphere, whereas the extent of the presence of large resin particles on the inner side of the outer shell is shown in FIGS. 6 is about 33% and about 30%, respectively. In FIGS. 5 and 6, since the thermally expandable microsphere has a shape far from the sphere, the particle diameter of the thermally expandable microsphere is determined by drawing a straight line passing through the approximate center of the thermally expandable microsphere. The maximum value of the distance between the intersection that intersects one outer shell outer surface and the intersection that intersects the other outer shell outer surface.

In either of the above Tables 1 and 2, the following abbreviations are used.
CMPEI: polyethyleneimines (substituted alkyl group: —CH ₂ COONa, substituted alkyl group substitution rate: 80%, weight average molecular weight: 50,000). In addition, it is described as carboxymethylated polyethyleneimine / Na salt.
EDTA: Ethylenediamine tetraacetate, 4Na, 4H2O (manufactured by Kirest Co., Ltd., trade name: Kirest 3D)
AN: acrylonitrile MAN: methacrylonitrile IBX: isobornyl methacrylate MMA: methyl methacrylate TMP: trimethylolpropane trimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.)
V-65: 2,2′-azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd.)
V-70: 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd.)
AIBN: 2,2′-azoisobutylnitrile (manufactured by Nippon Hydrazine Industry Co., Ltd.)
IPP: Diisopropyl peroxydicarbonate (Perroyl IPP-50, purity 50%, manufactured by NOF Corporation)
OPP: Di-2-ethylhexyl peroxydicarbonate (paroyl OPP, purity 70%, manufactured by NOF Corporation)
S (BP): di-sec-butyl peroxydicarbonate (Lupazole 225 or S (BP), purity 50%, manufactured by Arkema Yoshiaki Co., Ltd.)

[Example A1]
20 parts by weight of thermally expandable microspheres (softening point of the thermoplastic resin constituting the outer shell: 109 ° C.) obtained in Example 1 and heavy calcium carbonate (Whiteon SB red made by Shiroishi Calcium Co., Ltd .; laser) 80 parts by weight of an average secondary particle diameter by diffraction method of about 1.8 μm) was added to and mixed with a separable flask. Subsequently, it heated to 140 degreeC over 5 minutes, stirring, and obtained the hollow microparticles A (average particle diameter of 60 micrometers, true specific gravity 0.13).

[Comparative Example A1]
In Example A1, except that the thermally expandable microspheres obtained in Example 1 are changed to the thermally expandable microspheres obtained in Comparative Example 5 (softening point of the thermoplastic resin constituting the outer shell: 110 ° C.). Was added and mixed and heated in the same manner as in Example A1, and the foaming agent leaked out of the outer shell. The obtained hollow fine particles had a large true specific gravity due to the escape of the foaming agent, and were not suitable for weight reduction when mixed with the base material component.
The hollow fine particles can also be produced as follows by a wet heating expansion method described in JP-A No. 62-201231.

[Example B1]
An aqueous dispersion (slurry) containing 5% by weight of the thermally expandable microspheres obtained in Example 1 was prepared. According to the wet heating expansion method described in JP-A-62-201231, this slurry is fed from a slurry introduction tube to a foaming tube (diameter 16 mm, volume 120 ml, made of SUS304TP) at a flow rate of 5 L / min, and further steam ( (Temperature: 147 ° C., pressure: 0.3 MPa) was supplied from the steam introduction pipe, mixed with the slurry, and wet-heated and expanded. The slurry temperature (foaming temperature) after mixing was adjusted to 115 ° C.
The obtained slurry containing hollow fine particles was allowed to flow out from the foaming tube protrusion, mixed with cooling water (water temperature 15 ° C.), and cooled to 50 to 60 ° C. The cooled slurry liquid was dehydrated with a centrifugal dehydrator to obtain a hollow fine particle composition B1 (containing 90% by weight of water) containing 10% by weight of wet hollow fine particles.
The resulting hollow fine particles were isolated and the true specific gravity was 0.025. Moreover, the foaming agent retention before and after thermal expansion was 100%.

[Examples B2 to B4 and Comparative Examples B1 to B2]
In Examples B2 to B4 and Comparative Examples B1 to B2, the hollow microparticles were obtained in the same manner as in Example B1 except that the thermally expandable microspheres and the foaming temperature were changed as shown in Table 3 in Example B1. A hollow fine particle composition containing was obtained. Furthermore, the physical properties were evaluated and are shown in Table 3.
In the column of “Thermal expandable microspheres used” in Table 3, examples and comparative examples in which the respective thermally expandable microspheres were produced were shown.

[Example C1]
(Manufacture of cement composition)
Cement, quartzite, polypropylene fiber, waste paper crushed material and cellulose binder shown below were added to a Redige mixer (M20, manufactured by Matsubo) and stirred for 5 minutes and mixed well. Subsequently, the hollow fine particle composition obtained in Example B1 was added, and further stirred for 1 minute, and then sprayed and mixed with water over 2 minutes. The obtained mixture was transferred to a 10 L double arm kneader (HBN-10D manufactured by Honda Iron Works) and further mixed for 1 minute to produce a clay-like cement composition. The respective components and amounts (unit: parts by weight) contained in the cement composition are shown in Table 4.
Cement: Ordinary Portland cement (manufactured by Sumitomo Osaka Cement)
Silica: Silica Flower # 200 (made by Mizunami Silica)
Polypropylene fiber: PZL (Daiwabo)
Waste paper crushed material: PS (Nippon Paper Industries)
Cellulosic binder: Marporose ME-300000 (Matsumoto Yushi Seiyaku)

(Method for producing cement molding)
The cement composition obtained above was extruded using a vacuum extrusion molding machine (DE-50D manufactured by Honda Tekko Co., Ltd.) set to the following extrusion molding conditions, followed by primary curing (70 ° C., 12 hours) and autoclave Curing (170 ° C., 10 hours) was performed to produce a flat cement molded product.
[Extrusion conditions]
System temperature: 30 ° C
Degree of vacuum: -0.096 MPa or less Die size: 40 mm x 10 mm

The obtained cement molded product was cut to a constant volume, and the specific gravity was measured using an upper plate electronic analysis balance AX200 and a specific gravity measurement kit SMK-301 manufactured by Shimadzu Corporation.
The lower the specific gravity of the cement molding, the better the durability against breakage due to the stress generated during mixing and extrusion of hollow fine particles, and the lightening effect is exhibited. Therefore, the weight reduction effect of the cement molding was evaluated by its specific gravity. . The evaluation criteria for the weight reduction effect of the cement molded product were as follows, and the results were as shown in Table 4.
[Evaluation of lightening effect of cement molding]
A: The specific gravity of the cement molded product is less than 1.45.
○: The specific gravity of the cement molded product is 1.45 or more and less than 1.50.
(Triangle | delta): The specific gravity of a cement molding is 1.50 or more and less than 1.55.
X: The specific gravity of the cement molded product is 1.55 or more.

[Examples C2-C4 and Comparative Examples C1-C2]
In Examples C2 to C4 and Comparative Examples C1 to C2, the cements were obtained in the same manner as in Example C1, except that the components and amounts contained in the cement composition in Example C1 were changed as shown in Table 4. A molded product was produced.

  From the results of Table 4, it is clear that the cement composition containing the hollow fine particles of the present invention and an inorganic component such as cement has excellent performance.

[Example D1]
(Manufacture of ceramic composition and ceramic molding)
A ceramic composition was prepared by kneading cordierite used as a ceramic material with inorganic components, a cellulosic binder, the hollow fine particle composition obtained in Example B1 and water. The respective components and amounts (unit: parts by weight) contained in the ceramic composition are shown in Table 5.
The obtained ceramic composition was shaped by an extrusion molding method to form an unfired ceramic molded product.

In the same manner as in Example C1, the specific gravity of the obtained ceramic molded product was measured, and the weight reduction effect was evaluated according to the following evaluation criteria. The results were as shown in Table 5.
[Evaluation of weight reduction effect of ceramic molding]
A: The specific gravity of the ceramic molded product is less than 1.4.
○: The specific gravity of the ceramic molded product is 1.4 or more and less than 1.6.
Δ: The specific gravity of the ceramic molded product is 1.6 or more and less than 1.7.
X: The specific gravity of the ceramic molded product is 1.7 or more.

[Examples D2 to D4 and Comparative Examples D1 to D2]
In Examples D2 to D4 and Comparative Examples D1 to D2, ceramics were prepared in the same manner as in Example D1, except that the components and amounts contained in the ceramic composition in Example D1 were changed as shown in Table 5. A molding was created.

  From the results in Table 5, it is clear that the ceramic composition containing the hollow fine particles of the present invention and the inorganic component such as the ceramic material has excellent performance.

[Example E1]
(Manufacture of adhesive composition)
The hollow fine particles obtained by drying the hollow fine particle composition obtained in Example B1 were premixed with the one-component type modified silicone sealing material (Sikaflex-M1, Nippon Seika, specific gravity 1.40) as an organic component. Thereafter, the resulting mixture was stirred and degassed for 150 seconds under the rotation conditions of 500 rpm rotation and 2000 rpm revolution using a conditioning mixer (AR-360 manufactured by Sinky Corporation) to obtain an adhesive composition. It was. The respective components and amounts (unit: parts by weight) contained in the adhesive composition are shown in Table 6.
As a result of evaluating the specific gravity of the obtained adhesive composition by the method described in JIS A 1439, the specific gravity of the adhesive composition was 1.21, and the weight reduction effect was evaluated according to the following evaluation criteria. The results were as shown in Table 6.

[Evaluation of lightening effect of adhesive composition]
A: Specific gravity of the adhesive composition is less than 1.23.
○: Specific gravity of the adhesive composition is 1.23 or more and less than 1.26.
Δ: The specific gravity of the adhesive composition is 1.26 or more and less than 1.29.
X: The specific gravity of the adhesive composition is 1.29 or more.

[Examples E2-E4 and Comparative Examples E1-E2]
In Examples E2 to E4 and Comparative Examples E1 to E2, in Example E1, the respective components and amounts contained in the adhesive composition were changed as shown in Table 6, and were the same as Example E1. Evaluation was performed.

  From the results in Table 6, it is clear that the hollow fine particles of the present invention contribute to weight reduction of the adhesive composition without being broken even in the production stage of the adhesive composition.

1 Thermally expandable microspheres 2 Shell
3 Foaming agent (core)
4 Hollow fine particles A
5 Outer shell 6 Fine particle filler (adsorbed state)
7 Fine particle filler (indented and fixed state)
8 Hot Air Nozzle 9 Refrigerant Flow 10 Overheating Prevention Tube 11 Dispersion Nozzle 12 Colliding Plate 13 Gas Fluid Containing Thermally Expandable Microspheres 14 Gas Flow 15 Hot Air Flow

Claims (15)

A thermally expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent contained therein and vaporized by heating;
Thermally expandable microspheres, wherein the hollow microparticles obtained by thermal expansion have a repeated high-temperature pressure resistance of 75% or more, and the foaming agent retention before and after the thermal expansion is 80% or more.   The thermoplastic resin is obtained by polymerizing a polymerizable component, and the polymerizable component is a nitrile monomer, a (meth) acrylic acid ester monomer, a carboxyl group-containing monomer, or a styrene monomer. The thermally expandable microsphere according to claim 1, comprising at least one monomer component selected from vinyl acetate, acrylamide monomers, maleimide monomers, and vinylidene chloride.   The monomer component includes a nitrile monomer and a (meth) acrylic acid ester monomer, and the nitrile monomer occupies 80% by weight or more of the monomer component. Thermally expandable microspheres. A method for producing thermally expandable microspheres comprising an outer shell made of a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating,
A polyalkylenimine having a molecular weight of 1000 or more having at least one structure in which an alkyl group substituted with a hydrophilic functional group selected from a carboxylic acid (salt) group and a phosphonic acid (salt) group is bonded to a nitrogen atom, and polyvinylpyrrolidone In an aqueous dispersion medium in which an oily mixture containing a polymerizable component and the blowing agent is dispersed,
Including a step of polymerizing the polymerizable component using a polymerization initiator whose essential component is an azo compound having a 10-hour half-life temperature of 63 ° C. or less,
A method for producing thermally expandable microspheres.   5. The azo compound is 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) and / or 2,2′-azobis (2,4-dimethylvaleronitrile). A method for producing thermally expandable microspheres.   The method for producing thermally expandable microspheres according to claim 4 or 5, wherein the amount of the polyalkyleneimines is 0.0001 to 1 part by weight with respect to 100 parts by weight of the polymerizable component.   The polymerizable component is a nitrile monomer, (meth) acrylic acid ester monomer, carboxyl group-containing monomer, styrene monomer, vinyl acetate, acrylamide monomer, maleimide monomer And at least one monomer component selected from vinylidene chloride and the method for producing thermally expandable microspheres according to any one of claims 4 to 6.   The monomer component includes a nitrile monomer and a (meth) acrylic acid ester monomer, and the nitrile monomer occupies 80% by weight or more of the monomer component. A method for producing thermally expandable microspheres.   Hollow fine particles obtained by heating and expanding the thermally expandable microspheres according to any one of claims 1 to 3 and / or the thermally expandable microspheres obtained by the production method according to any one of claims 4 to 8.   The hollow microparticle according to claim 9, further comprising a microparticle filler attached to the outer surface of the outer shell.   A step of mixing the thermally expandable microspheres according to any one of claims 1 to 3 and / or the thermally expandable microspheres obtained by the production method according to any one of claims 4 to 8 and a fine particle filler; The mixture obtained in the mixing step is heated to a temperature above the softening point of the thermoplastic resin to expand the thermally expandable microspheres and attach the fine particle filler to the outer surface of the outer shell. The method for producing hollow fine particles according to claim 10, comprising a step.   The thermally expandable microsphere according to any one of claims 1 to 3, the thermally expandable microsphere obtained by the production method according to any one of claims 4 to 8, the hollow microparticle according to claim 9 or 10, And the composition containing at least 1 sort (s) of granular material chosen from the hollow microparticles obtained with the manufacturing method of Claim 11, and a base material component.   The composition according to claim 12, wherein the granular material is hollow fine particles, the content of the hollow fine particles is 0.1 to 10% by weight of the whole, and the base material component is an inorganic component.   The composition according to claim 12 or 13, wherein the inorganic component is at least one inorganic material selected from cements, cordierite, and silicon carbide.   A molded article formed by molding the composition according to claim 12.