JP2023077403A - Heat shielding composition, heat shielding material, and hollow particles used for heat shielding composition - Google Patents

Abstract

An object of the present invention is to provide a heat-shielding composition, a heat-shielding material, and hollow particles used in the heat-shielding composition capable of exhibiting excellent heat-shielding performance.
SOLUTION: Hollow particles (A) whose outer shell portion contains a thermoplastic resin and a base component (B) are included, and the ratio (r1/ r2) is 0.7 to 0.999, the average particle diameter of the particles (A) is 0.1 to 50 μm, and the particle residual rate after immersing the particles (A) in methyl ethyl ketone for 24 hours is A heat-shielding composition that is 50% or more.
[Selection diagram] Fig. 1

Description

TECHNICAL FIELD The present invention relates to a heat shielding composition, a heat shielding material, and hollow particles used in the heat shielding composition.

Thermal barrier properties are generally obtained by reflecting light in the wavelength range of 780-2100 nm. In addition, heat-shielding materials are applied to the roofs and exterior walls of buildings such as factories and houses, the roofs and exterior walls of containers, refrigerated trucks, etc., and the roofs and exterior walls of storerooms, thereby reducing the internal temperature caused by light. It can suppress the rise.
Pigments such as titanium oxide are generally used to exhibit heat shielding properties, but inorganic particles such as glass beads are also used to enhance the heat shielding effect.

In Patent Document 1, a paint containing hollow particles and a structure-retaining agent that maintains the arrangement structure of the hollow particles after forming a coating film, wherein hollow glass particles are used as the hollow particles to improve thermal conductivity and It is disclosed that it is possible to improve heat insulation and sound insulation since airborne noise can be reduced.
However, when hollow glass particles are used, a large amount of hollow glass particles are required to exhibit the heat shielding effect, and the dispersibility of the hollow glass particles is insufficient, resulting in poor coating properties. Additives must be added or the amount of hollow glass particles added must be suppressed, and there is a problem that the heat shielding performance cannot be sufficiently exhibited.

JP 2017-186452 A

Thus, there has been no heat-shielding composition capable of exhibiting sufficient heat-shielding performance.
An object of the present invention is to provide a heat-shielding composition, a heat-shielding material, and hollow particles used in the heat-shielding composition capable of exhibiting excellent heat-shielding performance.

As a result of intensive studies, the present inventors have found that the above problems can be solved by a heat shielding composition containing specific hollow particles and a base component, and have completed the present invention.
That is, the present invention comprises a hollow particle (A) whose outer shell contains a thermoplastic resin, and a base component (B), wherein the ratio (r1 /r2) is 0.7 to 0.999, the average particle diameter of the particles (A) is 0.1 to 50 μm, and the particle residual rate after immersing the particles (A) in methyl ethyl ketone for 24 hours is 50% or more.

The heat shielding composition of the present invention preferably satisfies at least one of the following 1) to 3).
1) The thermoplastic resin is a polymer of a polymerizable component containing a monomer (C) having one polymerizable carbon-carbon double bond, wherein the monomer (C) is a nitrile-based monomer The content of the nitrile-based monomer is 30 parts by weight or more based on 100 parts by weight of the monomer (C).
2) The content of the hollow particles (A) is 0.001 to 20 parts by weight per 100 parts by weight of the base component (B).
3) the coating composition;

The heat shielding material of the present invention is obtained by molding the above heat shielding composition.

Further, the present invention relates to hollow particles used in a heat shielding composition, wherein the outer shell contains a thermoplastic resin, and the ratio (r1/r2) of the inner diameter (r1) and the outer diameter (r2) is 0.7 to 0.999, an average particle diameter of 0.1 to 50 μm, and a residual rate of 50% or more after being immersed in methyl ethyl ketone for 24 hours.

The microparticle-attached hollow particles of the present invention contain the above-described hollow particles and microparticles, and the microparticles adhere to the outer shell surface of the hollow particles.

The heat-shielding composition of the present invention can exhibit excellent heat-shielding performance.
Since the heat shielding material of the present invention is obtained by molding the above heat shielding composition, it has excellent heat shielding performance.
The hollow particles used in the heat-shielding composition of the present invention can provide a heat-shielding composition capable of exhibiting excellent heat-shielding performance.

1 is a schematic diagram showing an example of microparticle-attached hollow particles; FIG. FIG. 2 is a schematic diagram of an expansion process section of a manufacturing apparatus for manufacturing hollow particles by a dry thermal expansion method. 1 is a schematic diagram of an apparatus for measuring the backside temperature of a test piece with a heat shield. FIG.

The heat shielding composition of the present invention essentially contains hollow particles (A) and a base component (B). Each component constituting the heat shielding composition will be described in detail below.

[Hollow particles (A)]
The hollow particles (A) (hereinafter sometimes simply referred to as particles (A)) are an essential component of the heat-shielding composition of the present invention, and are used in the heat-shielding composition.
The particle (A) has an outer shell containing a thermoplastic resin, and has a hollow portion corresponding to a cavity inside the particle. By forming the outer shell containing a thermoplastic resin, the particles (A) are lightweight, have high dispersibility, and exhibit excellent heat shielding performance.
Further, the particles (A) preferably include an outer shell and a hollow portion surrounded by the outer shell. Particles (A) are (substantially) spherical, and if the shape is exemplified by a familiar article, a soft tennis ball can be mentioned.
The particles (A) may be expanded bodies of thermally expandable microspheres, which will be described later.

The outer shell portion of the particles (A) is surrounded by the outer surface and the inner surface and has a continuous shape without end portions.
The hollow portion of the particles (A) is (substantially) spherical and is in contact with the inner surface of the outer shell portion. The hollow part is basically filled with gas and may have a liquefied state. Generally, it is preferable that the hollow part is one large hollow part, but there may be a plurality of hollow parts in the particle (A).

The ratio (r1/r2) of the inner diameter (r1) to the outer diameter (r2) of the particles (A) is 0.7 to 0.999. If the ratio is less than 0.7, the resulting heat shielding performance is lowered. On the other hand, when the ratio exceeds 0.999, the thickness of the outer shell of the particles (A) is thin, and the particles (A) are crushed or deformed during the production of the heat shielding composition or heat shielding material. . The upper limit of the ratio is preferably 0.99, more preferably 0.98, still more preferably 0.97, particularly preferably 0.95, most preferably 0.94. On the other hand, the lower limit of the ratio is preferably 0.75, more preferably 0.80, still more preferably 0.85.
The ratio of the inner diameter (r1) to the outer diameter (r2) of the particles (A) is according to the method described in the examples of the present invention.

The particles (A) have an average particle size of 0.1 to 50 μm. If the average particle size is less than 0.1 μm, the hollow particles aggregate, resulting in a decrease in dispersibility and a decrease in heat shielding performance. On the other hand, if the average particle size is more than 50 μm, the efficiency of reflecting infrared light is lowered, and the resulting heat shielding performance is lowered. The upper limit of the average particle size is preferably 40 μm, more preferably 35 μm, still more preferably 30 μm, particularly preferably 25 μm, most preferably 20 μm. On the other hand, the lower limit of the average particle size is preferably 0.3 µm, more preferably 0.5 µm, still more preferably 1 µm, and particularly preferably 2 µm.
Incidentally, the average particle size of the particles (A) is obtained by the method described in the examples of the present invention.

The ratio of the volume-based cumulative 90% particle size (D90) to the average particle size (D90/D50) of the particles (A) is not particularly limited, but is preferably 1.1-6. When the ratio is 1.1 or more, the dispersibility in the heat shield composition tends to be improved, and when the ratio is 6 or less, unevenness of the obtained heat shield tends to be reduced. The upper limit of the ratio is more preferably 5, still more preferably 4, and particularly preferably 3. On the other hand, the lower limit of the ratio is more preferably 1.2, still more preferably 1.3, particularly preferably 1.4.
The volume-based cumulative 90% particle diameter (D90) of the particles (A) is determined by the method described in the examples of the present invention.

Although the true specific gravity of the particles (A) is not particularly limited, it is preferably 0.003 to 0.6. When the true specific gravity is 0.003 or more, crushing and deformation of the particles (A) tend to be suppressed. On the other hand, when the true specific gravity is 0.6 or less, the heat shielding performance tends to be improved. The upper limit of the true specific gravity is more preferably 0.4, still more preferably 0.3, particularly preferably 0.2, most preferably 0.15. The lower limit of the true specific gravity is more preferably 0.005, still more preferably 0.01, and particularly preferably 0.03.
The true specific gravity of the particles (A) is determined by the method described in Examples of the present invention.

The particle residual rate of the particles (A) after being immersed in methyl ethyl ketone for 24 hours (hereinafter simply referred to as the particle residual rate) is 50% or more. If the particle residual rate is less than 50%, the strength of the thermoplastic resin forming the outer shell is low, and the particles (A) are crushed or deformed during the production of the heat shielding composition or heat shielding material. . Furthermore, when used together with an organic solvent, the particles (A) are greatly swollen by the organic solvent, and sufficient heat shielding performance cannot be exhibited. The particle retention rate is preferably 60 to 100%, more preferably 65 to 100%, even more preferably 70 to 100%, and particularly preferably 75 to 100%.
The residual rate of particles of particles (A) after being immersed in methyl ethyl ketone for 24 hours is determined by the method described in the examples of the present invention.

The outer shell portion that constitutes the particles (A) contains a thermoplastic resin. The thermoplastic resin that forms the outer shell of the particles (A) is not particularly limited, but includes a monomer (C) having one polymerizable carbon-carbon double bond, polymerizable carbon-carbon double bond It is preferably a polymer of a polymerizable component that may contain a monomer (D) having at least two bonds.

Examples of the monomer (C) contained in the polymerizable component include nitrile monomers such as acrylonitrile, methacrylonitrile, fumaronitrile and maleonitrile; vinyl halide monomers such as vinyl chloride; vinylidene halide monomers; vinyl ester monomers such as vinyl acetate, vinyl propionate and vinyl butyrate; unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid and cinnamic acid, Unsaturated dicarboxylic acids such as maleic acid, itaconic acid, fumaric acid, citraconic acid, chloromaleic acid, anhydrides of unsaturated dicarboxylic acids, monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, fumaric acid Carboxyl group-containing monomers such as unsaturated dicarboxylic acid monoesters such as monoethyl, monomethyl itaconate, monoethyl itaconate, and monobutyl itaconate; 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)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylic acid ester-based monomers such as (meth)acrylate; (meth)acrylamide-based monomers such as acrylamide, substituted acrylamide, methacrylamide, and substituted methacrylamide; N-phenylmaleimide, N-cyclohexylmaleimide and the like Maleimide-based monomers; styrene-based monomers such as styrene and α-methylstyrene; ethylenically unsaturated monoolefin-based monomers such as ethylene, propylene and isobutylene; vinyl ether monomers; vinyl ketone monomers such as vinyl methyl ketone; N-vinyl monomers such as N-vinylcarbazole and N-vinylpyrrolidone; vinylnaphthalene salts; itacones such as dimethyl itaconate and dibutyl itaconate Acid diesters and the like can be mentioned. Part or all of the carboxyl groups of the carboxyl group-containing monomer may be neutralized during or after polymerization. These monomer components may be used singly or in combination of two or more.
In the present invention, acrylic acid and methacrylic acid are sometimes collectively referred to as (meth)acrylic acid, (meth)acrylic means acrylic or methacrylic, and (meth)acrylate means acrylate or methacrylate. shall be

When the polymerizable component contains a nitrile-based monomer as the monomer (C), it is preferable from the viewpoint of improving the denseness and solvent resistance of the thermoplastic resin forming the outer shell. Although the content of the nitrile-based monomer is not particularly limited, it is preferably 30 parts by weight or more with respect to 100 parts by weight of the monomer (C). The upper limit of the content is preferably 100 parts by weight, more preferably 99.7 parts by weight, still more preferably 99.5 parts by weight, particularly preferably 99 parts by weight, most preferably 98 parts by weight. On the other hand, the lower limit of the content is more preferably 35 parts by weight, still more preferably 40 parts by weight, particularly preferably 45 parts by weight, and most preferably 50 parts by weight.

When the monomer (C) contains a nitrile-based monomer, the nitrile-based monomer preferably contains acrylonitrile and/or methacrylonitrile in terms of improving the rigidity of the thermoplastic resin forming the outer shell. , preferably acrylonitrile.
When the nitrile-based monomer contains acrylonitrile, its amount is not particularly limited, but is preferably 30 to 100 parts by weight per 100 parts by weight of the nitrile-based monomer. The upper limit of the content is more preferably 95 parts by weight, still more preferably 90 parts by weight, particularly preferably 80 parts by weight, and most preferably 70 parts by weight. On the other hand, the lower limit of the content is more preferably 35 parts by weight, still more preferably 40 parts by weight, particularly preferably 45 parts by weight, most preferably 50 parts by weight.
When the nitrile-based monomer contains methacrylonitrile, its amount is not particularly limited, but is preferably 5 to 100 parts by weight per 100 parts by weight of the nitrile-based monomer. The upper limit of the content is more preferably 70 parts by weight, still more preferably 65 parts by weight, particularly preferably 60 parts by weight, most preferably 50 parts by weight. On the other hand, the lower limit of the content is more preferably 10 parts by weight, still more preferably 20 parts by weight, and particularly preferably 30 parts by weight.

When the nitrile-based monomer contains acrylonitrile (AN) and methacrylonitrile (MAN), the weight ratio of AN and MAN (AN/MAN) is not particularly limited, but is preferably 30/70 to 99/1. be. The upper limit of the weight ratio is more preferably 90/10, still more preferably 87/13, particularly preferably 80/20. On the other hand, the lower limit of the weight ratio is more preferably 40/60, still more preferably 50/50, particularly preferably 55/45, most preferably 60/40.

When the monomer (C) contains a (meth)acrylic acid ester, it is preferable in that the glass transition temperature of the thermoplastic resin forming the outer shell can be adjusted, and the production conditions for the hollow particles (A) can be adjusted.
When the monomer (C) contains a (meth)acrylic acid ester, its amount is not particularly limited, but it is 0.2 to 70 parts by weight per 100 parts by weight of the monomer (C). The upper limit of the content is more preferably 60 parts by weight, still more preferably 50 parts by weight, particularly preferably 35 parts by weight, most preferably 20 parts by weight. On the other hand, the lower limit of the content is more preferably 0.5 parts by weight, still more preferably 0.7 parts by weight, and particularly preferably 1 part by weight.

When the monomer (C) contains a vinylidene halide monomer, it is preferable from the viewpoint of improving the gas barrier properties of the thermoplastic resin forming the outer shell.
When the monomer (C) contains a vinylidene halide-based monomer, the amount is not particularly limited, but preferably 0.2 to 70 parts by weight with respect to 100 parts by weight of the monomer (C). be. The upper limit of the content is more preferably 60 parts by weight, still more preferably 50 parts by weight, particularly preferably 35 parts by weight, most preferably 20 parts by weight. On the other hand, the lower limit of the weight ratio is more preferably 0.5 parts by weight, still more preferably 0.7 parts by weight, and particularly preferably 1 part by weight.

It is preferable that the monomer (C) contains a carboxyl group-containing monomer because the heat resistance of the thermoplastic resin forming the outer shell is improved.
Although the content of the carboxyl group-containing monomer is not particularly limited, it is preferably 0 to 80 parts by weight per 100 parts by weight of the monomer (C). The upper limit of the content is more preferably 70 parts by weight, still more preferably 60 parts by weight, particularly preferably 50 parts by weight, most preferably 45 parts by weight. On the other hand, the lower limit of the content is more preferably 5 parts by weight, still more preferably 10 parts by weight, particularly preferably 15 parts by weight, most preferably 20 parts by weight.

As mentioned above, the polymerizable component may contain the monomer (D). When the polymerizable component contains the monomer (D), the heat resistance and solvent resistance of the thermoplastic resin forming the outer shell are improved, which is preferable.
Examples of the monomer (D) include aromatic divinyl compounds such as divinylbenzene; allyl methacrylate, triacrylformal, triallyl isocyanate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol Di(meth)acrylate, neopentyl glycol di(meth)acrylate, polytetramethylene glycol diacrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9- nonanediol di(meth)acrylate, PEG#200 di(meth)acrylate, PEG#400 di(meth)acrylate, PEG#600 di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri( Polyfunctional compounds such as meth)acrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 2-butyl-2-ethyl-1,3-propanediol diacrylate, tricyclodecanedimethanol di(meth)acrylate, etc. (Meth)acrylate compounds and the like. These monomers (D) may be used singly or in combination of two or more.

The polymerizable component may not contain the monomer (D), but when the polymerizable component contains the monomer (D), the amount is not particularly limited, but the monomer (C) 100 parts by weight is preferably 0.01 to 10 parts by weight. The upper limit of the content is more preferably 0.1 parts by weight, still more preferably 0.3 parts by weight, and particularly preferably 0.5 parts by weight. On the other hand, the lower limit of the content is more preferably 6 parts by weight, still more preferably 3.5 parts by weight, particularly preferably 1.6 parts by weight, most preferably 1.1 parts by weight.

Particles (A) may contain a component that is vaporized by heating. When a component that vaporizes by heating is contained, the pressure inside the particles (A) is increased, the pressure resistance of the particles (A) is improved, the shape can be maintained, and the heat shielding performance to be imparted is improved.
Examples of components that vaporize by heating include propane, (iso)butane, (iso)pentane, (iso)hexane, (iso)heptane, (iso)octane, (iso)nonane, (iso)decane, and (iso) Hydrocarbons with 3 to 13 carbon atoms such as undecane, (iso)dodecane, and (iso)tridecane; Hydrocarbons such as petroleum fractions such as normal paraffins and isoparaffins having a boiling point of 150 to 260° C. and/or a distillation range of 70 to 360° C.; hydrocarbon halides; fluorine-containing compounds such as hydrofluoroethers; silanes having an alkyl group having 1 to 5 carbon atoms such as tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane, trimethyl-n-propylsilane; azo Compounds that are thermally decomposed by heating such as dicarbonamide, N,N'-dinitrosopentamethylenetetramine, 4,4'-oxybis(benzenesulfonylhydrazide) to generate gas, and the like. The component may be composed of one compound, or may be composed of a mixture of two or more compounds. The component may be linear, branched, or alicyclic, preferably aliphatic.
Although there are no particular limitations on the component that vaporizes upon heating, it is preferable to include a compound with a boiling point of 30° C. or lower, since the pressure resistance of the particles (A) is further improved. Further, the compound having a boiling point of 30° C. or less is preferably a hydrocarbon having 3 to 5 carbon atoms.

The content of the component that is vaporized by heating contained in the particles (A) is not particularly limited, but is preferably 0.5% by weight or more with respect to the entire particles (A). When the content is 0.5% by weight or more, there is a tendency to have sufficient pressure resistance. The upper limit of the content is preferably 20% by weight, more preferably 15% by weight, still more preferably 12% by weight, and particularly preferably 10% by weight. On the other hand, the lower limit of the content is more preferably 1% by weight, still more preferably 1.5% by weight, and particularly preferably 2% by weight.
The content of the component vaporized by heating the particles (A) is according to the method described in the examples of the present invention.

[Method for producing hollow particles (A)]
The hollow particles (A) contained in the heat shielding composition of the present invention are produced by, for example, a heat-expandable particle containing an outer shell containing a thermoplastic resin and a foaming agent contained therein and vaporized by heating. A manufacturing method including step 1 (expansion step) of heating and expanding microspheres can be mentioned. In addition, prior to the expansion step, it is necessary to produce heat-expandable microspheres. As a method for producing the heat-expandable microspheres, for example, an oily mixture containing the above-mentioned polymerizable component and foaming agent is prepared. A production method including step 2 (polymerization step) of polymerizing the polymerizable component using a polymerization initiator in the dispersed aqueous dispersion medium can be exemplified.
Therefore, the particles (A) can be produced through a polymerization step and an expansion step in that order.
The particles (A) contained in the heat-shielding composition of the present invention are manufactured through a step of heating and expanding the thermally expandable microspheres, as in the expansion step, in that the particles (A) can be obtained efficiently. preferably.

(Polymerization process)
Any foaming agent may be used as long as it is vaporized by heating, and a component that is vaporized by heating contained in the particles (A) described above may be used.
Further, when the particles (A) contained in the heat shielding composition of the present invention are expandable bodies obtained by expanding thermally expandable microspheres, the component of the particles (A) that is vaporized by heating is a thermally expandable Includes foaming agent contained in the microspheres.

In the polymerization step, by polymerizing the polymerizable component described above, a thermoplastic resin that forms the outer shell of the heat-expandable microspheres can be obtained.
Moreover, in the polymerization step, the polymerizable component is preferably polymerized in the presence of a polymerization initiator. The polymerization initiator is preferably contained in the oily mixture together with the polymerizable component and foaming agent.
The polymerization initiator is not particularly limited, but for example, peroxides such as peroxydicarbonate, peroxyester, and diacyl peroxide; azo compounds such as azonitriles, azoesters, azoamides, azoalkyls, and polymeric azo initiators; is mentioned. These polymerization initiators may be used alone or in combination of two or more. As the polymerization initiator, an oil-soluble polymerization initiator that is soluble in the polymerizable component is preferable.
The amount of the polymerization initiator is not particularly limited, but it is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, and 0.2 to 5 parts by weight with respect to 100 parts by weight of the polymerizable component. Parts by weight are more preferred.
In the polymerization step, the oily mixture may further contain a chain transfer agent and the like.

The aqueous dispersion medium is a medium mainly composed of water such as ion-exchanged water for dispersing the oily mixture, and may further contain an alcohol such as methanol, ethanol or propanol, or a hydrophilic organic solvent such as acetone. good. Hydrophilicity in the present invention means being arbitrarily miscible with water. The amount of the aqueous dispersion medium to be used is not particularly limited, but it is preferable to use 100 to 1000 parts by weight of the aqueous dispersion medium with respect to 100 parts by weight of the polymerizable component.

The aqueous dispersion medium may further contain an electrolyte. Examples of electrolytes include sodium chloride, magnesium chloride, calcium chloride, sodium sulfate, magnesium sulfate, ammonium sulfate, sodium carbonate and the like. These electrolytes may be used singly or in combination of two or more. The content of the electrolyte is not particularly limited, but is preferably 0.1 to 50 parts by weight per 100 parts by weight of the aqueous dispersion medium.

The aqueous dispersion medium is a water-soluble 1,1-substituted compound having a structure in which a hydrophilic functional group selected from a hydroxyl group, a carboxylic acid (salt) group and a phosphonic acid (salt) group and a heteroatom are bonded to the same carbon atom. Polyalkyleneimines having a 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, water-soluble ascorbic acids, water-soluble polyphenols , water-soluble B vitamins, potassium dichromate, alkali metal nitrite; metal (III) halides, boric acid, and water-soluble phosphonic acids (salts) containing at least one water-soluble compound selected from You may The term "water-soluble" as used in the present invention means a state in which 1 g or more is dissolved in 100 g of water.
The amount of the water-soluble compound contained in the aqueous dispersion medium is not particularly limited. 0.1 parts by weight, more preferably 0.001 to 0.05 parts by weight.

The aqueous dispersion medium may contain a dispersion stabilizer and a dispersion stabilizing aid in addition to the electrolyte and water-soluble compound.
The dispersion stabilizer is not particularly limited, but examples thereof include tribasic calcium phosphate, magnesium pyrophosphate obtained by a metathesis synthesis method, calcium pyrophosphate, colloidal silica, alumina sol, and magnesium hydroxide. These dispersion stabilizers may be used singly or in combination of two or more.
The content of the dispersion stabilizer is preferably 0.05 to 100 parts by weight, more preferably 0.2 to 70 parts by weight, per 100 parts by weight of the polymerizable component.
The dispersion stabilizing aid is not particularly limited. Active agents may be mentioned. These dispersion stabilizing aids may be used singly or in combination of two or more.

The aqueous dispersion medium is prepared, for example, by blending water (ion-exchanged water) with an electrolyte, a water-soluble compound, a dispersion stabilizer, a dispersion stabilizing aid, and the like, if necessary. The pH of the aqueous dispersion medium during polymerization is appropriately determined according to the types of water-soluble compound, dispersion stabilizer, and dispersion stabilizing aid.
In the polymerization step, polymerization may be carried out in the presence of sodium hydroxide or sodium hydroxide and zinc chloride.

In the polymerization step, the oily mixture is suspended and dispersed in an aqueous dispersion medium so as to prepare spherical oil droplets having a predetermined particle size.
As a method for suspending and dispersing the oily mixture, for example, a method of stirring with a homomixer (eg, manufactured by Primix Co., Ltd.) or a static mixer (eg, manufactured by Noritake Engineering Co., Ltd.) or the like is used. method, membrane suspension method, ultrasonic dispersion method, and other general dispersion methods.
Suspension polymerization is then initiated by heating a dispersion in which the oily mixture is dispersed as spherical oil droplets in an aqueous dispersion medium. It is preferable to stir the dispersion during the polymerization reaction, and the stirring may be carried out gently enough to prevent floating of the monomers and sedimentation of the heat-expandable microspheres after polymerization, for example.

The polymerization temperature is freely set depending on the type of polymerization initiator, but is preferably controlled in the range of 30 to 100°C, more preferably 40 to 90°C. The time for which the reaction temperature is maintained is preferably about 1 to 20 hours. The initial polymerization pressure is not particularly limited, but is in the range of 0 to 5 MPa, more preferably 0.2 to 3 MPa in terms of gauge pressure.

The obtained slurry is filtered by a centrifugal separator, a pressure press, a vacuum dehydrator or the like to obtain a cake-like product having a water content of 10 to 50% by weight, preferably 15 to 45% by weight, more preferably 20 to 40% by weight. Then, the cake-like material is dried with a tray dryer, an indirect heating dryer, a fluidized bed dryer, a vacuum dryer, a vibration dryer, a flash dryer, etc., and the moisture content is 5% by weight or less, preferably 3% by weight or less. , more preferably 1% by weight or less of dry powder.
Alternatively, the slurry may be dried with a spray dryer, a fluidized bed dryer, or the like to obtain a dry powder.

In this way, heat-expandable microspheres containing a shell containing a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating are obtained.
The average particle size of the heat-expandable microspheres obtained by the polymerization step is not particularly limited, but is preferably 0.05 to 25 μm, more preferably 0.1 to 20 μm, still more preferably 0.3 to 15 μm, and particularly preferably is 0.5-12 μm, most preferably 0.7-12 μm.
The heat-expandable microspheres obtained by the polymerization process preferably have a true specific gravity of 0.97 to 1.30, more preferably 1.05 to 1.20. When the true specific gravity of the heat-expandable microspheres is within the above range, there is a tendency that the particles (A) can be efficiently obtained.

(Expansion process)
The expansion step is not particularly limited as long as it is a step of heating and expanding the heat-expandable microspheres, and may be either a dry heat expansion method or a wet heat expansion method.
Examples of the dry thermal expansion method include the method described in JP-A-2006-213930, particularly the internal injection method. As the wet thermal expansion method, there is a method described in JP-A-62-201231. The temperature for heating and expanding the heat-expandable microspheres is preferably 80 to 450°C.

When the particles (A) are thermally expandable microspheres, it is preferable that the particles (A) have sufficient expansion capacity from the standpoint of pressure resistance. The expansion capacity of the particles (A) means the property of further expansion (re-expansion) when the hollow particles are heated.
The expansion reserve power factor of the hollow particles is not particularly limited, but is preferably 1 to 80%. When the residual power factor is 1% or more, the pressure resistance tends to be improved, and when it is 80% or less, the heat shielding performance to be imparted tends to be improved. The upper limit of the reserve power factor is more preferably 75%, still more preferably 70%, and particularly preferably 65%. On the other hand, the lower limit of the reserve power factor is more preferably 5%, still more preferably 10%, and particularly preferably 15%. The expansion reserve power factor of the unexpanded thermally expandable microspheres exceeds approximately 95%.
The expansion reserve power factor indicates the degree of expansion of the hollow particles at the maximum re-expansion, and the true specific gravity (d ₁ ) of the hollow particles and the true specific gravity (d ₂ ) of the hollow particles at the maximum re-expansion are measured. and is calculated by the following formula (1).
Expansion reserve power factor (%) = (1-d ₂ /d ₁ ) x 100 (1)

When the particles (A) have an expansion reserve power factor, they preferably have a re-expansion start temperature (T _S2 ). The re-expansion start temperature (T _S2 ) of the particles (A) is not particularly limited, but is preferably 60 to 210°C. When the re-expansion start temperature (T _S2 ) of the particles (A) is 70° C. or higher, the heat shielding performance to be imparted tends to be improved, and when it is 180° C. or lower, the particles (A) have sufficient pressure resistance. tend to have The upper limit of the re-expansion initiation temperature is more preferably 150°C, still more preferably 130°C, and particularly preferably 120°C. On the other hand, the lower limit of the re-expansion initiation temperature is more preferably 75°C, still more preferably 80°C, and particularly preferably 85°C.
The re-expansion start temperature (T _S2 ) of the particles (A) is determined by the method described in Examples of the present invention.

When the particles (A) have an expansion reserve power factor, they preferably have a maximum re-expansion temperature (T _max2 ). Although the maximum re-expansion temperature (T _max2 ) of the particles (A) is not particularly limited, it is preferably 90 to 200°C. When the maximum re-expansion temperature (T _max2 ) of the particles (A) is 90° C. or higher, the heat shielding performance to be imparted tends to be improved, and when it is 200° C. or lower, the particles (A) have sufficient pressure resistance. tend to have The upper limit of the maximum re-expansion temperature is more preferably 150°C, still more preferably 130°C. On the other hand, the lower limit of the maximum re-expansion temperature is more preferably 100°C, still more preferably 105°C, and particularly preferably 110°C.
The maximum re-expansion temperature (T _max2 ) of the particles (A) is determined by the method described in Examples of the present invention.

[Fine particle-attached hollow particles]
The heat-shielding composition may use microparticle-attached hollow particles during its production. The microparticle-attached hollow particles include the above-described hollow particles (hollow particles (A)) and microparticles, and the microparticles are attached to the outer surface of the outer shell of the hollow particles. It is like The term "adhesion" as used herein may simply refer to the state (4) in which the fine particles (4 and 5) are adsorbed to the outer surface of the outer shell (2) of the hollow particles, and the outer shell near the outer surface may be in a state (4). It means that the thermoplastic resin to be formed may be softened or melted by heating, and fine particles may be embedded in the outer surface of the outer shell of the hollow particles and fixed (5). The particle shape of the fine particles may be amorphous or spherical.

Various kinds of particles can be used as the fine particles, and they may be inorganic or organic. Examples of the shape of the fine particles include spherical, needle-like, and plate-like shapes.
The inorganic substance constituting the fine particles is not particularly limited. Dolomite, calcium sulfate, barium sulfate, glass flakes, boron nitride, silicon carbide, silica, alumina, mica, titanium dioxide, zinc oxide, magnesium oxide, zinc oxide, hydrosaltite, carbon black, molybdenum disulfide, tungsten disulfide, ceramic beads, glass beads, crystal beads, glass microballoons, and the like.
Pigments, which will be described later, may be used as the inorganic substance that constitutes the fine particles.

The organic matter constituting the fine particles is not particularly limited, but examples include sodium carboxymethylcellulose, hydroxyethylcellulose, methylcellulose, ethylcellulose, nitrocellulose, hydroxypropylcellulose, sodium alginate, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, carboxyvinyl. Polymer, polyvinyl methyl ether, magnesium stearate, calcium stearate, zinc stearate, polyethylene wax, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid amide, hydrogenated castor oil, (meth)acrylic resin, polyamide resin, silicone resin , urethane resin, polyethylene resin, polypropylene resin, fluorine-based resin, and the like.
Inorganic substances and organic substances constituting fine particles may be treated with surface treatment agents such as silane coupling agents, paraffin wax, fatty acids, resin acids, urethane compounds, and fatty acid esters, or may be untreated.

The average particle size of the fine particles 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 average particle size is a volume-based cumulative 50% particle size value measured by a laser diffraction method. The ratio between the average particle size of fine particles and the average particle size of hollow particles (average particle size of fine particles/average particle size of hollow particles) is not particularly limited, but in terms of adhesion of fine particles to hollow particle surfaces, it is preferable. is 1 or less, more preferably 0.1 or less, and still more preferably 0.05 or less.

The weight ratio of the fine particles to the whole fine-particle-attached hollow particles is not particularly limited, but is preferably 95% by weight or less, more preferably 90% by weight or less, particularly preferably 85% by weight or less, and most preferably 80% by weight or less. is. If the weight ratio is more than 95% by weight, the amount to be added becomes large when preparing a composition using fine-particle-attached hollow particles, which may be uneconomical. The lower limit of the weight percentage of fine particles is preferably 10% by weight, more preferably 20% by weight, particularly preferably 30% by weight, and most preferably 40% by weight.

The true specific gravity of the microparticle-attached hollow particles is not particularly limited, but is preferably 0.01 to 0.6. When the true specific gravity is 0.01 or more, crushing and deformation of the microparticle-attached hollow particles tend to be suppressed. On the other hand, when the true specific gravity is 0.6 or less, there is a tendency that the heat shielding performance exhibited is improved. The upper limit of the true specific gravity is more preferably 0.5, still more preferably 0.4, particularly preferably 0.3, most preferably 0.20. On the other hand, the lower limit of the true specific gravity is more preferably 0.03, more preferably 0.05, particularly preferably 0.07, most preferably 0.1.

Fine particle-attached hollow particles can be obtained, for example, by thermally expanding fine particle-attached heat-expandable microspheres. As a method for producing fine particle-attached hollow particles, there is a step of mixing heat-expandable microspheres and fine particles (mixing step), and the mixture obtained in the mixing step is mixed with a thermoplastic resin that forms the outer shell of the heat-expandable microspheres. A preferred manufacturing method includes a step of heating to a temperature above the softening point of to expand the heat-expandable microspheres and attaching fine particles to the outer surface of the obtained hollow particles (adhesion step).

(Mixing process)
The mixing step is a step of mixing thermally expandable microspheres and microparticles.
The weight ratio of fine particles to the total of heat-expandable microspheres and fine particles in the mixing step is not particularly limited, but is preferably 95% by weight or less, more preferably 90% by weight or less, particularly preferably 85% by weight or less, and most preferably. is 80% by weight or less. When the weight ratio is 95% by weight or less, the resulting fine-particle-adhered hollow particles tend to be lightweight, and a sufficient effect of lowering the specific gravity tends to be obtained. The lower limit of the weight ratio is preferably 5% by weight, more preferably 10% by weight, particularly preferably 20% by weight, and most preferably 30% by weight.

In the mixing step, the device used to mix the heat-expandable microspheres and the fine particles is not particularly limited, and a device having a very simple mechanism such as a container and stirring blades can be used. Alternatively, a powder mixer capable of general shaking or stirring may be used.
Examples of powder mixers include ribbon mixers and vertical screw mixers. In recent years, more efficient and multi-functional powder mixers combined with a stirring device, Super Mixer (manufactured by Kawata Co., Ltd.), High Speed Mixer (manufactured by Fukae Co., Ltd.), New Gram Machine (manufactured by Seishin Enterprise Co., Ltd.) , SV mixer (manufactured by Kobelco Eco-Solutions Co., Ltd.) or the like may be used.

(Adhesion process)
The adhering step is a step of heating the mixture obtained in the mixing step described above to a temperature above the softening point of the thermoplastic resin forming the outer shell of the thermally expandable microspheres. In the adhering step, the heat-expandable microspheres are expanded and the microparticles are adhered to the outer surface of the outer shell of the obtained hollow particles.
Heating may be performed using a general contact heat transfer type or direct heating type mixing drying apparatus. The function of the mixing-type drying device is not particularly limited, but it is preferable to have a temperature controllable ability to disperse and mix raw materials, and optionally a decompression device or a cooling device for speeding up drying. Devices used for heating include, for example, Loedige Mixer (manufactured by Matsubo Co., Ltd.) and Solid Air (Hosokawa Micron Co., Ltd.).
The temperature conditions for heating depend on the type of thermally expandable microspheres, but the optimum expansion temperature is preferred, preferably 70 to 250°C, more preferably 80 to 230°C, further preferably 90 to 220°C. be.

Even when the fine particle-attached hollow particles are obtained by expanding thermally expandable microspheres, it is preferable that the hollow particles constituting the fine particle-attached hollow particles have an expansion margin, as described above.
When the fine particle-attached hollow particles have residual expansion power, the residual expansion power factor of the constituent hollow particles is preferably in the same numerical range as the residual expansion power factor of the particles (A) described above. Further, when the fine particle-attached hollow particles have an expansion margin, the re-expansion start temperature and maximum re-expansion temperature of the fine particle-attached hollow particles are respectively the re-expansion start temperature and maximum re-expansion temperature of the particles (A) described above. It is preferable that they are in the same numerical range.

[Base material component (B)]
The base component (B) (hereinafter sometimes simply referred to as component (B)) is an essential component of the heat-shielding composition. Component (B) is not particularly limited, and can be appropriately selected according to the form and application of the heat shielding composition.
Examples of component (B) include natural rubber, isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), butyl rubber, silicone rubber, acrylic Rubbers such as rubber, urethane rubber, fluororubber, ethylene-propylene-diene rubber (EPDM); thermosetting resins such as epoxy resin, melanin resin, phenolic resin, unsaturated polyester resin, polyurethane; resin waxes such as polyethylene wax ; ethylene-vinyl acetate copolymer (EVA), polyethylene, modified polyethylene, polypropylene, modified polypropylene, modified polyolefin, acrylic resin, thermoplastic polyurethane, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer coalescence (ABS resin), polystyrene (PS), polylactic acid (PLA), polybutylene succinate (PBS), polyhydroxyalkanoate (PHA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyacetal (POM) Ionomer resins such as ethylene ionomers, urethane ionomers and styrene ionomers; Thermoplastic elastomers such as olefin elastomers, styrene elastomers and polyester elastomers; Bioplastics such as starch resins. In addition, vinyl chloride resin, acrylic resin, polyurethane resin, polyester resin, melamine resin, epoxy resin, ethylene-vinyl acetate copolymer (EVA), rubber such as natural rubber and styrene rubber, etc. and plasticizer Also included are plastisols containing these, resin emulsions containing these and a liquid dispersion medium, resin-containing liquids such as latex, and the like.
Among these components (B), rubbers, thermoplastic resins, and resin-containing liquids are preferred from the standpoint of moldability of the heat shield material.

[Other ingredients]
In addition to the particles (A) and component (B), the heat-shielding composition of the present invention may optionally contain pigments, inorganic fillers, organic fillers, plasticizers, stabilizers, lubricants, rheology modifiers, and interfaces. Other ingredients such as activators, antioxidants and the like may be included.
Pigments include, for example, white pigments such as titanium oxide; black pigments such as Paliogen (registered trademark) Black L 0086 (manufactured by BASF) and Sicopal (registered trademark) Black 0095 (manufactured by BASF); Fastogen (registered trademark) Blue Blue pigments such as 5485K (manufactured by DIC Corporation), Fastogen (registered trademark) Blue RSE (manufactured by DIC Corporation), Cyanine Blue 5240KB (manufactured by Dainichiseika Kogyo Co., Ltd.); Fastogen (registered trademark) Super Magenta RH (manufactured by DIC Corporation); (manufactured by DIC Corporation), Fastogen (registered trademark) Red7100Y (manufactured by DIC Corporation), and red pigments such as Rubicron Red 400RG (manufactured by DIC Corporation).
Examples of inorganic fillers include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, alumina, titanium oxide, magnesium oxide, calcium oxide, zinc oxide, antimony trioxide, antimony pentoxide, calcium sulfate, barium sulfate, and potassium carbonate. , magnesium carbonate, aluminum silicate, calcium silicate, magnesium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, calcium aluminum silicate, wollastonite, glass beads and the like.

Examples of organic fillers include cellulose fibers such as cotton fiber, hemp fiber and kenaf fiber, cellulose powder such as paper powder, wood powder, bamboo powder, rice husk powder and fruit husk powder, and starch.
Plasticizers include, for example, phthalates; adipates; sebacates; azelaates; phosphates; Epoxy-based plasticizers and the like are included.

Examples of lubricants include metal soaps such as calcium stearate, magnesium stearate, barium stearate, lead stearate, zinc stearate, calcium laurate, barium laurate, zinc laurate, and calcium ricinoleate; paraffin wax, liquid paraffin, etc. hydrocarbon waxes; amide waxes such as stearic acid amide, oleic acid amide, erucic acid amide, methylenebisstearic acid amide, and ethylenebisstearic acid amide; esters such as stearic acid monoglyceride, stearyl stearate, and butyl stearate Wax; fatty acid wax such as stearic acid; higher alcohol wax such as stearyl alcohol;

Examples of rheology modifiers include methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyacrylic acid, polyethylene glycol, polyethylene oxide, polyoxyethylene/polypropylene block polymer, polyalkylene glycol derivatives, polyvinyl alcohol, ethylene-modified polyvinyl alcohol, and polyvinylpyrrolidone. , gum arabic, guar gum, xanthan gum, gelatin, corn starch, polyacrylamide, polyethyleneimine, polynaphthalenesulfonate, polycarboxylic acid-based copolymers, vinyl alcohol-based copolymers, vinylpyrrolidone-based copolymers, and the like.
Examples of surfactants include anionic surfactants and nonionic surfactants.
Examples of antioxidants include phenolic antioxidants such as n-octadecyl-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate, tris(2,4-di- Phosphorus-based antioxidants such as t-butylphenyl)phosphite and the like are included.

The heat-shielding composition of the present invention can be prepared by mixing the hollow particles (A), the base component (B) and, if necessary, other components. Alternatively, a composition obtained by mixing the hollow particles (A) and the base component (B) may be further mixed with another base component (B) to form a heat shielding composition. can.

[Heat shield composition and method for producing the same]
The heat shielding composition of the present invention essentially contains the hollow particles (A) described above and the base component (B) described above, and is molded to provide excellent heat shielding performance. can be obtained.
The heat shielding composition of the present invention is preferably a coating composition in that the heat shielding material can be produced more efficiently. is preferably a composition of

In the heat-shielding composition of the present invention, the content of the particles (A) is not particularly limited, but is preferably 0.001 to 20 parts by weight per 100 parts by weight of the component (B). When the content is 0.001 parts by weight or more, there is a tendency that the heat shielding performance that can be exhibited is improved. On the other hand, when the content is 20 parts by weight or less, there is a tendency that the physical properties of component (B) can be maintained more efficiently. The upper limit of the content is more preferably 15 parts by weight, still more preferably 12 parts by weight, and particularly preferably 10 parts by weight. On the other hand, the lower limit of the content is more preferably 0.01 parts by weight, still more preferably 0.1 parts by weight, particularly preferably 0.5 parts by weight, and most preferably 1 part by weight.

The method for producing the heat-shielding composition of the present invention is not particularly limited, but conventionally known methods may be employed. Examples of the method include mixing using a mixer such as a disper, a homomixer, a static mixer, a Henschel mixer, a tumbler mixer, a planetary mixer, a mixer, a single-screw kneader, a twin-screw kneader, and a multi-screw kneader. There is a method to make

[Thermal insulation material and its manufacturing method]
The heat shielding material of the present invention is obtained by molding the heat shielding composition described above, and has excellent heat shielding properties. The form of the heat shielding material of the present invention includes a coating film, a film, a sheet, and the like, and can be applied to roofs and exteriors of buildings, roadbeds such as asphalt roads, and the like.

When the heat shielding material of the present invention has a layer containing the particles (A), the thickness of the layer is not particularly limited, but is preferably 50 to 1000 μm. When the thickness is 50 µm or more, the film tends to have good heat shielding performance, and when it is 1000 µm or less, the economic efficiency tends to be improved.
The heat shielding material of the present invention may have only a layer containing the particles (A), or may have other layers such as a protective layer in addition to the layer containing the particles (A).

Although the specific gravity of the heat shielding material of the present invention is not particularly limited, it is preferable that the heat shielding material has uniform performance and good heat shielding performance when it is 0.4 to 1.0. The upper limit of the specific gravity is more preferably 0.9, still more preferably 0.8, and particularly preferably 0.7. On the other hand, the lower limit of the specific gravity is more preferably 0.5.

The heat shielding material of the present invention can be produced by, for example, a spraying method, a flow heat shielding method, a roll coating method, a bar coating method, a brush coating method, a dip heat shielding method, a spin heat shielding method, and a screen printing method. , casting method, gravure printing method, flexographic printing method and the like; extrusion molding; injection molding; calendar molding; inflation molding; blow molding;
When the heat shielding material is formed by the method of coating, drying may be performed after coating, and after drying, heat treatment at 100 ° C. or less, ultraviolet irradiation, etc. is preferably performed to the extent that the performance of the heat shielding material is not impaired. may be performed.

Examples of the present invention will be specifically described below. However, the present invention is not limited to these examples. In the following examples and comparative examples, "%" means "% by weight" and "parts" means "parts by weight" unless otherwise specified.
In addition, the physical properties of the heat-expandable microspheres, hollow particles, and fine-particle-attached hollow particles used below, and the heat-shielding compositions and heat-shielding materials mentioned in Examples and Comparative Examples were measured according to the following procedures. Further performance was evaluated. Hereinafter, thermally expandable microspheres are sometimes referred to as "microspheres" for simplicity.

[Measurement of average particle size of heat-expandable microspheres]
As a measuring device, a laser diffraction scattering type particle size distribution measuring device (Microtrac ASVR, manufactured by Nikkiso Co., Ltd.) was used, and the D50 value by volume-based measurement was taken as the average particle diameter.

[Measurement of average particle size of hollow particles]
A laser diffraction particle size distribution analyzer (Mastersizer 3000 (Malvern)) was used and measured by a dry measurement method. The D50 value based on volume-based measurement was adopted as the average particle size.
Regarding the hollow particles wet with water, the hollow particles obtained by drying the hollow particles were measured for the average particle size.

[Measurement of moisture content]
The water content of the heat-expandable microspheres and hollow particles was measured using a Karl Fischer moisture meter (MKA-510N, manufactured by Kyoto Electronics Industry Co., Ltd.). The water content of the heat-expandable microspheres was C _W1 (%).

[Measurement of Content of Foaming Agent Contained in Thermally Expandable Microspheres]
1.0 (g) of the dried heat-expandable microspheres was placed in a stainless steel evaporating dish having a diameter of 80 mm and a depth of 15 mm, and its weight W ₃ (g) was measured. After adding 30 mL of acetonitrile and dispersing it uniformly, it was allowed to stand at room temperature for 2 hours, and the weight W ₄ (g) after drying at 110° C. for 2 hours was measured. From the measured W ₃ , W ₄ and C _W1 , the foaming agent content CR ₁ (% by weight) was calculated from the following formula.
CR ₁ = ((W ₃ −W ₄ )/1.0)×100−C _W

[Measurement of Content of Component Vaporized by Heating Contained in Hollow Particles]
The content of the component contained in the hollow particles and vaporized by heating was measured by headspace gas chromatography as follows.
0.1 g of hollow particles was weighed into a 20 mL headspace vial, and the headspace vial was sealed with a silicone rubber septum coated with a fluororesin and an aluminum cap. After heating the sealed headspace vial at 170° C. for 20 minutes and pressurizing with helium for 0.5 minutes, 3 mL of the gas phase (headspace) was collected, introduced into a gas chromatograph, and the hollow particles contained by heating The contents of vaporizable components were measured.
The analysis conditions for the headspace gas chromatography method were as follows.
(Analysis conditions)
GC column; Agilent DB-624 length 30 m, inner diameter 0.25 mm, film thickness 1.40 μm)
Detector: FID, temperature 200°C
Temperature rising program: after holding at 40°C for 6 minutes, heating up to 200°C at a rate of 20°C/min, 20
After reaching 0°C, the temperature was maintained for 3 minutes.
Inlet temperature: 200°C
Gas introduction amount: 3 mL
Helium flow rate: 1 mL/min
Split ratio: 10:1
A calibration curve method was adopted as the quantification method, and the following method was used.
(Conditions for quantitative method)
5 μL of a solution in which a known amount of sample was dissolved in DMF was collected in a 20 mL headspace vial, and the headspace vial was sealed with a fluororesin-coated silicone rubber septum using an aluminum cap. The hermetically capped headspace vial was heated at 170° C. for 20 minutes, pressurized with helium for 0.5 minutes, and then 3 mL of gas phase (headspace) was sampled and introduced into a gas chromatograph.
As for the microparticle-adhered hollow particles, first, as a pretreatment, an operation of washing off the microparticles from the microparticle-adhered hollow particles was performed. Specifically, the microparticle-attached hollow particles, water, and if necessary, an acid or a base were mixed, and the mixture was stirred to decompose or wash away the microparticles. Subsequently, solid-liquid separation was carried out by filtering this. By repeating this operation several times, hollow particles were obtained from which fine particles were removed from the fine particle-adhered hollow particles. For example, when the microparticles are calcium carbonate or magnesium hydroxide, hollow particles to which microparticles are not adhered can be taken out by repeating the water washing process several times after washing with hydrochloric acid or the like.
The resulting hollow particles were then dried to adjust the moisture content to 1% or less (the ash content was analyzed and found to be less than 5% by weight). Then, the amount of the component contained in the hollow particles and vaporized by heating was measured in the same manner as described above.
In addition, the hollow particles wet with water were dried in an environment of 40° C. or lower as a pretreatment to obtain hollow particles adjusted to a water content of 1% or lower. The amount of the component contained in the obtained hollow particles and vaporized by heating was measured in the same manner as described above.

[Measurement of ash]
The dried sample Wp (g) is placed in a crucible, heated with an electric heater, and ignited at 700° C. for 30 minutes to be incinerated, and the weight of the resulting ash Wq (g) is measured. The ash content CA (% by weight) of the sample is calculated from Wp (g) and Wq (g) by the following formula.
CA (% by weight) = (Wq/Wp) x 100
Here, the ash content was measured using thermally expandable microspheres or hollow particles as the samples. A sample with a moisture content of 1% or less was used for the measurement of ash content.

[Measurement of expansion start temperature (T _S1 ), maximum expansion temperature (T _max1 ), and maximum displacement (H _max1 )]
A DMA (DMA Q800 type, manufactured by TA Instruments) was used as a measuring device. Put 0.5 mg of thermally expandable microspheres in an aluminum cup with a diameter of 6.0 mm (inner diameter of 5.65 mm) and a depth of 4.8 mm, and put an aluminum lid (diameter of 5.6 mm, thickness of 0) on top of the thermally expandable microsphere layer. .1 mm) was applied to prepare the sample. The height of the sample was measured while a force of 0.01 N was applied to the sample from above by a pressurizer. The sample was heated from 20° C. to 300° C. at a rate of temperature increase of 10° C./min while a force of 0.01 N was applied by the presser, and the amount of displacement of the presser in the vertical direction was measured. The temperature at which the displacement in the positive direction starts is the expansion start temperature (T _S1 ) of the thermally expandable microspheres, and the temperature at which the maximum amount of displacement (H _max1 ) is exhibited is the maximum expansion temperature (T _max1 ) of the thermally expandable microspheres. and

[Measurement of re-expansion start temperature (T _S2 ) and maximum re-expansion temperature (T _max2 )]
Measurements of the expansion start temperature and the maximum expansion temperature were performed in the same manner, except that 0.5 mg of the heat-expandable microspheres were replaced with 0.5 mg of the hollow particles. The positive displacement start temperature (T _S2 ) of the hollow particles was defined as the re-expansion start temperature (T s2 ), and the temperature at which the maximum amount of displacement (H _max2 ) was exhibited was defined as the maximum re-expansion temperature (T _max2 ) of the hollow particles.
As for the microparticle-attached hollow particles, the re-expansion start temperature and maximum re-expansion temperature were measured in the same manner except that 3.0 mg of the microparticle-attached hollow particles were used.
For the hollow particles wet with water, hollow particles are obtained by the method described in the method for measuring the content of the component that is vaporized by heating contained in the hollow particles, and the re-expansion start temperature and maximum re-expansion temperature of the obtained hollow particles are measured. Expansion temperature measurements were taken in the same manner as described above.

[Measurement of true specific gravity (d ₁ ) of hollow particles]
The true specific gravity (d ₁ ) of the hollow particles was measured by a liquid immersion method (Archimedes method) using isopropyl alcohol in an atmosphere with an ambient temperature of 25° C. and a relative humidity of 50%.
Specifically, a volumetric flask with a capacity of 100 mL was emptied, and after drying, the volumetric flask weight (WB1) was measured. After accurately filling the weighed volumetric flask with isopropyl alcohol up to the meniscus, the weight (WB2) of the volumetric flask filled with 100 mL of isopropyl alcohol was weighed.
Also, a volumetric flask with a volume of 100 mL was emptied, and after drying, the volumetric flask weight (WS1) was measured. A weighed volumetric flask was filled with about 50 mL of hollow particles and the weight of the volumetric flask (WS2) was weighed. Then, the volumetric flask filled with the hollow particles was accurately filled with isopropyl alcohol up to the meniscus without air bubbles, and the weight (WS3) was weighed. Then, the obtained WB1, WB2, WS1, WS2 and WS3 were introduced into the following formula to calculate the true specific gravity (d ₁ ) of the hollow particles.
d ₁ = {(WS2-WS1)×(WB2-WB1)/100}/{(WB2-WB1)-(WS3-WS2)}
In addition, in the fine particle-attached hollow particles or the water-wet matter of the hollow particles, the hollow particles are obtained by the method described in the method for measuring the content of the component contained in the hollow particles that is vaporized by heating. The true specific gravity of the particles was measured in the same manner as described above.

[Measurement of true specific gravity (d ₂ ) at maximum re-expansion of hollow particles]
The true specific gravity (d ₂ ) of the hollow particles at maximum re-expansion was measured by the following measuring method.
A box with a flat bottom of 12 cm long, 13 cm wide and 9 cm high was prepared from aluminum foil, and 1.0 g of hollow particles or fine particles-attached hollow particles (hereinafter generally referred to simply as a hollow particle sample) was uniformly placed in the box. The temperature was raised by 5 ° C. from the re-expansion start temperature obtained by measuring the re-expansion start temperature, and after heating for 1 minute at each temperature, the true specific gravity of the re-expanded hollow particle sample was measured as above. It was measured in the same manner as the true specific gravity (d ₁ ) of hollow particles. The one showing the lowest true specific gravity among them was taken as the true specific gravity (d') at the time of maximum re-expansion of the hollow particle sample. When the hollow particle sample is hollow particles, the true specific gravity (d') is the true specific gravity (d ₂ ) at maximum re-expansion.
In addition, in the water wet matter of hollow particles, hollow particles are obtained by the method described in the method for measuring the content of the component contained in the hollow particles that is vaporized by heating, and the obtained hollow particles are measured as a hollow particle sample. bottom.
(Measurement of true specific gravity (d ₂ ) of hollow particles at the time of maximum re-expansion of fine particle-attached hollow particles)
When the hollow particle sample is fine particle-attached hollow particles, the hollow particles are obtained from the fine particle-attached hollow particles exhibiting the lowest true specific gravity by the method described in the method for measuring the content of the component contained in the hollow particles and vaporized by heating. rice field. The true specific gravity (d ₂ ) at maximum re-expansion was measured in the same manner as the true specific gravity (d ₁ ) of the hollow particles thus obtained.

[Measurement of true specific gravity (d ₃ ) of fine particle-attached hollow particles]
In the measurement of the true specific gravity (d ₁ ) of the hollow particles, the true specific gravity (d ₁ ) of the fine particle-attached hollow particles was measured in the same manner as in the measurement of the true specific gravity (d 1 ) of the hollow particles, except that the fine particle-attached particles were used instead of the hollow particles. Specific gravity ( _d3 ) was measured.

[Particle retention rate of hollow particles after immersion in methyl ethyl ketone]
The particle retention rate of the hollow particles after being immersed in methyl ethyl ketone was measured as follows.
First, 1.0 g of hollow particles was weighed into a screw tube with a volume of 100 mL. Next, 50 mL of methyl ethyl ketone was added to the screw tube containing the hollow particles and allowed to stand at 25° C. for 24 hours to immerse the hollow particles in methyl ethyl ketone. After 24 hours, centrifugation was carried out at 2000 rpm for 2 minutes, and the gel-like portion swollen by methyl ethyl ketone was precipitated at the bottom. The hollow particles remaining on the top were transferred to an aluminum heat-resistant container (W1), placed in a dryer, and dried at 40°C for 24 hours. The weight of the aluminum heat-resistant container used was measured in advance before the remaining hollow particles were transferred (W1).
After drying, the weight (W2) of the hollow particles and the heat-resistant container was measured, the dry weight (W=W2-W1) of the remaining hollow particles was obtained, and the residual ratio of the hollow particles was calculated from the following formula.
Percentage of hollow particles remaining (%) = (dry weight of remaining hollow particles (W)/1.0) x 100
In addition, in the fine particle-attached hollow particles or the water-wet matter of the hollow particles, the hollow particles are obtained by the method described in the method for measuring the content of the component contained in the hollow particles that is vaporized by heating. The particle retention rate of the hollow particles after the particles were immersed in methyl ethyl ketone was measured in the same manner as described above.

[Measurement of true specific gravity of outer shell of hollow particles]
The true specific gravity (dp) of the outer shell resin (thermoplastic resin forming the outer shell portion) of the hollow particles was measured as follows.
Specifically, 5 g of hollow particles were dispersed in 200 mL of N,N-dimethylformamide, treated with an ultrasonic disperser for 30 minutes, and allowed to stand at room temperature for 24 hours. After 24 hours, it was dried under reduced pressure at 120° C. for 5 hours to obtain a shell resin. The true specific gravity (d ₄ ) of the obtained outer shell resin was measured in the same manner as in the measurement of the true specific gravity (d ₁ ) of the hollow particles except that the outer shell resin was used instead of the hollow particles. The measured true specific gravity of the outer shell resin was taken as the true specific gravity (dp) of the outer shell portion of the hollow particles.

[Measurement of inner diameter (r1) and outer diameter (r2) of hollow particles]
From the measured true specific gravity (d ₁ ) of the hollow particles and the true specific gravity (dp) of the outer shell portion of the hollow particles, the inner diameter (r1) of the hollow particles was calculated from the following formula. Also, the ratio (r1/r2) between the inner diameter (r1) and the outer diameter (r2) was calculated.
r1=(r2)×[{(dp)−(d ₁ )}/(dp)] ^1/3
r2 = (average particle diameter of hollow particles)/2

[Measurement of Hollow Ratio of Hollow Particles]
From the measured inner diameter (r1) and outer diameter (r2) of the hollow particles, the hollow ratio of the hollow particles was calculated by the following formula.
Hollow ratio of hollow particles (%) = (r1/r2) ³ × 100

[Measurement of Specific Gravity of Heat Shielding Composition]
The specific gravity of the heat shield composition obtained by the procedures and ratios described in Examples and Comparative Examples was measured by a method according to JIS K 5600-2-4.
Specifically, a specific gravity cup (manufactured by TP Giken Co., Ltd.) with a capacity of 50 mL was emptied, and after drying, the weight (WB3) of the specific gravity cup was measured. After filling the heat shielding composition to the rim of the weighed specific gravity cup, the lid is closed from the top, the inside is filled with the heat shielding composition, and the total weight of the heat shielding composition and the lightweight cup (WB4) is weighed. bottom.
Then, from the weighed WB3 and WB4, the liquid specific gravity (d ₅ ) of the heat shielding composition was calculated from the following formula.
d ₅ = (WB4-WB3)/50

(Production Example 1, Production Example of Thermally Expandable Microspheres)
After adding 85 g of colloidal silica containing 20% by weight of active ingredient and 3 g of adipic acid-diethanolamine condensate containing 50% by weight of active ingredient to 500 g of ion-exchanged water, the pH of the resulting mixture was adjusted to 3.0 to 4.0. to prepare an aqueous dispersion medium.
Separately, 125 g of acrylonitrile, 55 g of methacrylonitrile, 20 g of methyl methacrylate, 1.0 g of ethylene glycol dimethacrylate, 20 g of isobutane, 10 g of isopentane, and 2 g of di-2-ethylhexylperoxydicarbonate are mixed to form an oily mixture. prepared.
The prepared aqueous dispersion medium and oily mixture were mixed, and the resulting mixture was dispersed at 12000 rpm for 5 minutes with a homomixer to prepare a suspension. This suspension was transferred to a pressurized reactor having a capacity of 1.5 liters, and after nitrogen substitution, the initial reaction pressure was set to 0.2 MPa, and polymerization was carried out at a polymerization temperature of 70° C. for 15 hours while stirring at 80 rpm. The resulting polymerized product was filtered and dried to obtain heat-expandable microspheres 1 (microspheres 1). Table 1 shows the physical properties of Microsphere 1 obtained.

(Production Examples 2 to 10, Production Examples of Thermally Expandable Microspheres)
Thermally expandable microspheres 2 to 10 (microsphere 2 10) were obtained, respectively. Tables 1 and 2 show the physical properties of each of the obtained thermally expandable microspheres.
In Tables 1 and 2, the following abbreviations are used.
AIBN: 2,2'-azobis(isobutyronitrile)
OPP: di-2-ethylhexyl peroxydicarbonate (purity 70%)
Isobutane: 2-methylpropane, boiling point -12°C
Isopentane: 2-methylbutane, boiling point 28°C

(Production Example A1, Method for producing hollow particles)
Microspheres 1 obtained in Production Example 1 were heated by a dry thermal expansion method to produce hollow particles.
The internal injection method described in Japanese Patent Application Laid-Open No. 2006-213930 was employed as the dry thermal expansion method. Specifically, using the manufacturing apparatus having the foaming process section shown in FIG. 2, the heat-expandable microspheres were heated and expanded according to the following procedure to manufacture hollow particles.

(Description of the foaming process section)
As shown in FIG. 2, the foaming process section includes a gas introduction pipe (not numbered) equipped with a dispersion nozzle (11) at the outlet and arranged in the center, and a A collision plate (12), a desuperheating cylinder (10) spaced around the gas introduction pipe, and a hot air nozzle (8) spaced around the desuperheating cylinder (10). Prepare. In this foaming process section, a gas fluid (13) containing heat-expandable microspheres is caused to flow in the direction of the arrow in the gas introduction pipe, and into the space formed between the gas introduction pipe and the overheating prevention tube (10). has a gas flow (14) flowing in the direction of the arrow for improving the dispersibility of the thermally expandable microspheres and preventing overheating of the gas introduction pipe and the impingement plate, and furthermore, an overheating prevention tube (10) and a hot air nozzle. A hot air flow for thermal expansion flows in the direction of the arrow in the space formed between (8). Here, the hot air flow (15), the gaseous fluid (13) and the gaseous flow (14) generally flow in the same direction. A coolant flow (9) flows in the direction of the arrow inside the overheating prevention tube (10) for cooling.
(Operation of manufacturing equipment)
In the injection step, the gaseous fluid (13) containing the thermally expandable microspheres is caused to flow 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) is is jetted from the dispersion nozzle (11).
In the dispersing step, the gaseous fluid (13) is made to collide with a collision plate (12) installed downstream of the dispersing nozzle (11) so that the thermally expandable microspheres are evenly dispersed in the hot air stream (15). to be operated. Here, the gaseous fluid (13) emerging from the dispersion nozzle (11) is guided together with the gaseous stream (14) towards the impingement plate (12) and collides with it.
In the expansion step, the dispersed heat-expandable microspheres are heated in a hot air flow (15) to a temperature equal to or higher than the expansion start temperature and expanded. After that, the obtained hollow particles are collected by, for example, passing through a cooling section.

(Expansion conditions and results)
In Production Example A1, the production apparatus shown in FIG. 2 was used, and the expansion conditions were a raw material supply amount of 0.8 kg/min, a raw material dispersed gas amount of 0.35 m ³ /min, a hot air flow rate of 8.0 m ³ /min, and a hot air temperature of 290. ℃, and hollow particles 1 were obtained. Table 3 shows the physical properties of the obtained hollow particles 1.

(Production Examples A2 to A4 and Comparative Production Examples A1 to A3, Method for producing hollow particles)
In Production Example A1, the heat-expandable microspheres 1 obtained in Production Example 1 were replaced with the heat-expandable microspheres obtained in Production Examples 2-4 and 8-10. Hollow particles were obtained in the same manner except that the manufacturing conditions were changed. Tables 3 and 4 show the physical properties of each of the obtained hollow particles.
The changed manufacturing conditions for the hollow particles are as follows: Hot air temperature of 240°C for Production Example A2, Hot air temperature of 220°C for Production Example A3, Hot air temperature of 270°C for Production Example A4, and Hot air temperature of 280°C for Comparative Production Example A1. °C, the temperature of the hot air was 260°C in Comparative Production Example A2, and the temperature of hot air was 240°C in Comparative Production Example A3.

(Production Example A5, production method of water-wet product of hollow particles)
An aqueous dispersion (slurry) containing 3% by weight of the heat-expandable microspheres 5 obtained in Production Example 5 was prepared. According to the wet superheat expansion method described in JP-A-62-201231, this slurry is fed from a slurry introduction pipe into a foaming pipe (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 a steam introduction pipe, mixed with the slurry, and expanded by wet heating. The slurry temperature (foaming temperature) after mixing was adjusted to 115°C.
The obtained slurry containing the hollow particles was allowed to flow out from the projection of the foaming tube, 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 water-wet product containing 33% by weight of hollow particles 5 (containing 67% by weight of water).
The obtained hollow particles 5 were isolated and their physical properties were measured. Table 3 shows the results.

(Manufacturing Examples A6 and A7, method for manufacturing hollow particles in water)
In Production Example A5, except that the heat-expandable microspheres 5 obtained in Production Example 5 were replaced with the heat-expandable microspheres obtained in Production Examples 6 and 7, and the production conditions were changed to the following: Water wet products of hollow particles were obtained in the same manner. The obtained hollow particles were isolated and their physical properties were measured. The results are shown in Tables 3-4.
In addition, the manufacturing conditions for the water-wetted hollow particles that were changed were that the expansion temperature was 125°C for Production Example A6, and the expansion temperature was 110°C for Production Example A7.

(Production Example A8, Method for producing fine particle-attached hollow particles)
40 parts by weight of the thermally expandable microspheres 1 obtained in Production Example 1 and 60 parts of calcium carbonate (manufactured by Bihoku Funka Kogyo Co., Ltd.: Whiten SB Red) were added to a separable flask and mixed. Next, while stirring, the temperature was raised to 140° C. over 5 minutes to obtain fine particle-attached hollow particles 8, and their physical properties were measured. Table 4 shows the results.

(Production Example A9, Method for producing fine particle-attached hollow particles)
In Production Example A8, the heat-expandable microspheres 1 obtained in Production Example 1 were replaced with the heat-expandable microspheres obtained in Production Example 2, and titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.: Fine particle-adhered hollow particles 2 were obtained in the same manner except that Typaque CR-50) was used and the heating temperature was changed up to 120°C. The physical properties of the obtained fine particle-attached hollow particles 9 were measured. Table 4 shows the results.

(Example 1)
Solvent-based urethane resin (Vylon UR-1400, manufactured by Toyobo Co., Ltd., active ingredient 30%, solvent: methyl ethyl ketone/isopropyl alcohol = 35/35) is added to 50 parts by weight of hollow particles 1 at a rate of 1.0 part by weight. The mixture was uniformly dispersed and defoamed with a stirring deaerator to obtain a heat shielding composition. The resulting heat shielding composition contained 40% by volume of the hollow particles 1 and had a specific gravity of 0.74.
Next, the obtained heat shielding composition was applied to an OHP film having a thickness of 0.1 mm using a coater so that the coating thickness after drying was 300 μm, and a test piece 1 having a heat shielding material was obtained. rice field. The solar reflectance of the obtained test piece 1 was measured by the method described later. Table 5 shows the results.
In addition, the obtained heat shielding composition 1 was applied to an aluminum plate having a thickness of 0.8 mm using a coater so that the coating thickness after drying was 300 μm, and a test piece 2 having a heat shielding material was obtained. rice field. The temperature of the back surface of the obtained test piece 2 on which the heat insulating material was present was measured by the method described later. Table 5 shows the results.

(Examples 2-6, Comparative Examples 1-9)
In Example 1, the hollow particles 1 obtained in Production Example A1 were changed to the hollow particles obtained in Production Examples A2 to A4, Production Examples A8 to A9, and Comparative Production Examples A1 to A3, and the amount added is shown in Table 5. A heat shielding composition was obtained in the same manner except that the amount was changed to that shown in 1 to 6. The physical properties of each heat shielding composition obtained were measured. The results are shown in Tables 5-6.
Furthermore, in Comparative Examples 4 to 8, heat shielding compositions were obtained in the same manner as in Example 1 except that the other components shown in Table 6 and their amounts were added without adding the hollow particles.
As for the other components listed in Table 6, those shown below were used.
Glass beads: Glass Bubbles VS5500 (manufactured by 3M Japan Ltd.)
Calcium carbonate: Whiten SB Red (manufactured by Bihoku Funka Kogyo Co., Ltd.)
Titanium oxide: TITANIX JR-600A (manufactured by Tayca Corporation)
Next, using the obtained heat shielding composition, test pieces 1 and 2 having a heat shielding material were obtained in the same manner as in Example 1. The solar reflectance and back surface temperature of each test piece obtained were measured and evaluated. The results are shown in Tables 5-6.
In Comparative Example 9, only the solvent-based urethane resin was applied in the same manner as in Example 1, test pieces 1 and 2 were obtained, and measurements and evaluations were performed.

(Example 7)
To 50 parts by weight of water-based urethane paint (for water-based glossy urethane buildings, active ingredient 48%, transparent, manufactured by Dainippon Toryo Co., Ltd.), hollow particles 5 obtained in Production Example A5 were wetted with water (hollow particle content: 33 %) was added and uniformly dispersed to obtain a heat shielding composition. The resulting heat shielding composition contained 40.7% by volume of hollow particles 1 and had a specific gravity of 0.80.
Next, the obtained heat shielding composition was applied to an OHP film having a thickness of 0.1 mm and an aluminum plate having a thickness of 0.8 mm using a coater, and in the same manner as in Example 1, a test piece having a heat shielding material. 1 and specimen 2 were obtained. In the same manner as in Example 1, the solar reflectance and the back surface temperature of each test piece were measured. Table 5 shows the results.

(Examples 8-9)
In Example 7, the water-wetted hollow particles 5 obtained in Production Example A5 were replaced with the water-wetted hollow particles obtained in Production Examples A6 and A7, and the amount added was shown in Table 5. Heat shielding compositions were obtained in the same manner, except for changing to The physical properties of each heat shielding composition obtained were measured. Table 5 shows the results.
Next, using the obtained heat shielding composition, in the same manner as in Example 1, test pieces 1 and 2 having a heat shielding material were obtained. The solar reflectance and back surface temperature of each test piece obtained were measured and evaluated. Table 5 shows the results.

(Example 10)
A heat shielding composition was obtained in the same manner as in Example 1, except that the pigment Paliogen Black L 0086 was added in the amount shown in Table 5. The physical properties of the resulting heat shield composition were measured. Table 5 shows the results.
Next, using the obtained heat shielding composition, in the same manner as in Example 1, test pieces 1 and 2 having a heat shielding material were obtained. The solar reflectance and back surface temperature of the obtained test piece were measured and evaluated. Table 5 shows the results.

(Example 11)
A heat shielding composition was obtained in the same manner as in Example 7, except that the pigment Blue 5484K was added in the amount shown in Table 6. The physical properties of the resulting heat shield composition were measured. Table 6 shows the results.
Next, using the obtained heat shielding composition, in the same manner as in Example 1, test pieces 1 and 2 having a heat shielding material were obtained. The solar reflectance and back surface temperature of each test piece obtained were measured and evaluated. Table 6 shows the results.

<Measurement of solar reflectance>
For the test piece 1, a UV-Vis-IR spectrophotometer (Shimadzu Corporation: Solid Spec 3700) was used to measure the surface spectral reflectance in the measurement wavelength range of 300-2500 nm. Based on the obtained spectral reflectance, the solar reflectance was calculated based on JIS K 5602, and the heat shielding performance of the heat shielding material was evaluated according to the following criteria.
x: The solar reflectance is less than 50%.
◯: Solar reflectance is 50% or more and less than 75%.
〇〇: Solar reflectance is 75% or more and less than 85%.
〇〇〇: The solar reflectance is 85% or more.

<Measurement of rear surface temperature>
The test piece 2 was evaluated for heat shielding performance using the testing apparatus shown in FIG. The evaluation procedure is as follows.
As shown in Fig. 3, cut off the upper part of a 40 cm cubic heat insulating container (17, styrofoam, etc.), and place a test piece (16, aluminum plate with a thickness of 0.8 mm) on top so that the coated surface faces up. installed.
A thermocouple (18) for a temperature sensor was fixed on the back side of the test piece with cellophane tape, and the temperature change on the back side was measured.
Using a 50 W reflector bulb (20) as a heat source, light was applied vertically from the test piece at a distance of 10 cm. The back surface temperature was measured 10 minutes after the start of irradiation. The measurement of the rear surface temperature was performed in an atmosphere of 25° C. with no wind.

[Measurement of specific gravity of heat insulating material]
In the measurement of the true specific gravity (d ₁ ) of the hollow particles, the specific gravity of the heat insulating material is measured in the same manner as the measurement of the true specific gravity (d ₁ ) of the hollow particles, except that the heat insulating material is used instead of the hollow particles. It was measured. The heat insulating material was cut into a size of 2 cm in width and 0.5 cm in depth for the measurement.

As can be seen from Tables 5 and 6, when the outer shell portion is a specific hollow particle (A) containing a thermoplastic resin and a heat shielding composition containing a base component (B), the solar reflectance is 50% or more. can be imparted with excellent heat-shielding performance, and the heat-shielding material obtained from the heat-shielding composition can suppress an increase in the back surface temperature of the member having the heat-shielding material.
On the other hand, when hollow particles with an average particle diameter not in the range of 0.1 to 50 μm are included (Comparative Example 1), the ratio of the inner diameter to the outer diameter (r1/r2) is not in the range of 0.7 to 0.999. When containing (Comparative Example 2), when containing hollow particles whose particle residual rate after immersion in methyl ethyl ketone for 24 hours is not 50% or more (Comparative Examples 1 and 3), and when the outer shell contains a thermoplastic resin When the particles (A) were not contained (Comparative Examples 4 to 9), the solar reflectance was less than 50% and the heat shielding performance was poor. In addition, the heat shielding material obtained from the heat shielding composition has a high rear surface temperature of the member having the heat shielding material. Among them, in Comparative Examples 4 to 6, the dispersibility of the inorganic powder in the resin was low, so that the powder was not uniformly present in the obtained heat shielding material.

REFERENCE SIGNS LIST 1 fine particle-attached hollow particle 2 outer shell portion 3 hollow portion 4 fine particle (adsorbed state)
5 fine particles (embedded, fixed state)
8 Hot air nozzle 9 Refrigerant flow 10 Overheat prevention cylinder 11 Dispersion nozzle 12 Collision plate 13 Gas fluid containing thermally expandable microspheres 14 Gas flow 15 Hot air flow 16 Test piece 17 Insulated container 18 Temperature sensor 19 Temperature sensor body 20 Reflector (50 W )
21 AC power supply

Claims (7)

Hollow particles (A) whose outer shell contains a thermoplastic resin, and a base component (B),
The ratio (r1/r2) of the inner diameter (r1) to the outer diameter (r2) of the particles (A) is 0.7 to 0.999,
The particles (A) have an average particle diameter of 0.1 to 50 μm,
A heat shielding composition, wherein the particles (A) have a particle residual rate of 50% or more after being immersed in methyl ethyl ketone for 24 hours. The thermoplastic resin is a polymerizable component polymer containing a monomer (C) having one polymerizable carbon-carbon double bond, wherein the monomer (C) is a nitrile-based monomer. The heat shield composition according to claim 1, wherein the content of the nitrile-based monomer is 30 parts by weight or more based on 100 parts by weight of the monomer (C). 3. The heat shielding composition according to claim 1, wherein the content of said particles (A) is 0.001 to 20 parts by weight per 100 parts by weight of said component (B). 3. The heat shielding composition according to claim 1, which is a coating composition. A heat shield material obtained by molding the heat shield composition according to claim 1 or 2. A hollow particle used in a heat shielding composition,
The outer shell contains a thermoplastic resin,
The ratio (r1/r2) of the inner diameter (r1) to the outer diameter (r2) is 0.7 to 0.999,
an average particle size of 0.1 to 50 μm,
Hollow particles having a residual rate of 50% or more after being immersed in methyl ethyl ketone for 24 hours. 7. Microparticle-adhered hollow particles comprising the hollow particles according to claim 6 and microparticles, wherein the microparticles adhere to the outer surface of the outer shell of the hollow particles.

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