JP5943555B2 - Thermally expandable microspheres and their applications - Google Patents

Description

  The present invention relates to thermally expandable microspheres and uses thereof.

Thermally expandable microspheres having a structure in which a thermoplastic resin is used as an outer shell and a foaming agent is enclosed therein are generally called thermal expandable microcapsules (thermally expandable microspheres). As the thermoplastic resin, a vinylidene chloride copolymer, an acrylonitrile copolymer, an acrylate copolymer, or the like is usually used. Moreover, hydrocarbons, such as isobutane and isopentane, are mainly used as a foaming agent (refer patent document 1).
When these thermally expandable microspheres are heated and expanded, hollow fine particles are obtained. For example, Patent Documents 2 and 3 introduce hollow fine particles having polar groups on the surface, which are difficult to be destroyed during mixing and forming of a ceramic composition. However, the crushing resistance improvement (durability improvement) at the time of mixing and molding is insufficient.

Patent Document 4 discloses hollow fine particles obtained by heating and foaming thermally expandable microcapsules having an outer shell formed of a polymer obtained from a specific monomer and a crosslinking agent and having an expansion ratio of 20 to 100 times. It is described that it is blended into lightweight cement products. However, even with these hollow fine particles, the improvement in durability is insufficient.
Furthermore, Patent Document 5 discloses a mixture of hollow microparticles and thermally expandable microcapsules that are not easily destroyed during mixing and molding of a ceramic composition. However, this mixture only sharpens the particle size distribution and is not an essential improvement in durability.

Patent Document 6 describes hollow fine particles exhibiting excellent repeated compression durability. In the measurement of repeated compression durability, the hollow fine particles were pressurized from 2.5 N to 18 N at a very slow pressurization rate of 10 N / min, and then from 18 N to 2.5 N at a very slow depressurization of 10 N / min. A series of operations for releasing pressure at a speed is repeated eight times. Here, pressurization and depressurization are both performed gently, and the hollow fine particles exhibiting excellent repeated compression durability are restored until they are almost spherical when the applied pressure is the lowest of 2.5N.
However, when actually using the hollow fine particles, it is very rare to receive a “static pressure change” in which pressure is gently applied or gently removed as described above. The hollow fine particles are usually very often mixed under pressure, transferred by piping, or filled. In that case, the hollow fine particles are subjected to “dynamic pressure change” in which pressurization and depressurization are repeatedly performed in a short time. Even hollow microparticles with excellent compression durability against “static pressure changes” are deformed and removed by pressurization when the interval between pressurization and depressurization is repeated in a short time. It was found that the compression durability is not always excellent when subjected to a “dynamic pressure change” in which the state of further pressurization is repeated before being restored to a spherical shape by pressure.

US Pat. No. 3,615,972 JP 2003-327482 A JP 2003-327383 A JP 2004-131361 A JP 2005-067943 A International Publication No. 2007/058379 Pamphlet

  An object of the present invention is to provide thermally expandable microspheres that are hollow microparticles having excellent durability against dynamic pressure changes when thermally expanded, and uses thereof. Hereinafter, “durability against dynamic pressure change” may be abbreviated as “dynamic durability”.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be achieved if they are thermally expandable microspheres containing a specific amount of two specific types of compounds, and the present invention has been achieved. did.
That is, the thermally expandable microsphere according to the present invention is a thermally expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating. The agent is a hydrocarbon having 3 to 12 carbon atoms, contains a straight chain hydrocarbon (A) having 13 or more carbon atoms and an ester (B) represented by the following general formula (1), and the total of these two components (a + B) Ri weight ratio 0.05 to 3 wt% der occupied in the heat-expandable microspheres, wherein the linear hydrocarbon (a) is a compound represented by the following general formula (2), wherein The ester (B) is a compound represented by the following general formula (3) .

R ¹ COOR ² (1)
(However, R ¹ and R ² are linear hydrocarbon groups and may be the same or different. )

n-C _2X H _{4X + 2} (2)
(However, X is a number from 7 to 18.)
n-C _Y H _{2Y + 1} COO (n-C _Z H _{2Z + 1} ) (3)
(However, Y is a number from 6 to 18, and Z is a number from 6 to 18.)

Here, it is preferable that | X−Y |, | Y−Z |, and | Z−X | are all 3 or less. Moreover, it is preferable in said X, Y, and Z being all the numbers of 11-15.
Further, another thermally expandable microsphere according to the present invention is a thermally expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent encapsulated therein and vaporized by heating, The foaming agent is a hydrocarbon having 3 to 12 carbon atoms, and contains a linear hydrocarbon (A) having 13 or more carbon atoms and an ester (B) represented by the above general formula (1), and these two components The weight ratio of the total (A + B) to the thermally expandable microspheres is 0.05 to 3% by weight, and the weight ratio (A / B) of the linear hydrocarbon (A) to the ester (B) There, Ru 35 / 65-80 / 20 der.

The thermoplastic resin is composed of a copolymer obtained by polymerizing a monomer component containing a nitrile monomer, and the weight ratio of the nitrile monomer in the monomer component is 80% by weight. The above is preferable. Moreover, it is preferable that a fine particle filler adheres to the outer shell.
The hollow fine particles according to the present invention can be obtained by heating and expanding the thermally expandable microspheres.

The composition concerning this invention contains the said thermally expansible microsphere and / or hollow microparticle, and a base material component. The base material component may be at least one inorganic material selected from cements, cordierite, and silicon carbide. This composition is preferably an adhesive composition.
The molded product according to the present invention is formed by molding the above composition.

The thermally expandable microspheres of the present invention can provide hollow fine particles having excellent dynamic durability when thermally expanded.
The hollow fine particles of the present invention are obtained by thermally expanding thermally expandable microspheres and have excellent dynamic durability.

Since the composition of the present invention contains the above heat-expandable microspheres and / or hollow fine particles, it is excellent in dynamic durability.
Since the molded product of the present invention is obtained by molding the above composition, it is lightweight and has excellent dynamic durability.

It is the schematic which shows an example of a thermally expansible microsphere. It is an example of the schematic diagram of microparticles | fine-particles adhering hollow microparticles. It is the schematic of the foaming process part of the manufacturing apparatus used for the manufacturing method of a hollow microparticle for dynamic durability measurement. It is the schematic of the measuring apparatus of dynamic durability.

[Thermal expandable microspheres and method for producing the same]
As shown in FIG. 1, for example, the thermally expandable microsphere (1) of the present invention comprises an outer shell (2) made of a thermoplastic resin and a foaming agent (3) encapsulated therein and vaporized by heating. It is a thermally expansible microsphere comprised.
The average particle diameter of the thermally expandable microsphere is not particularly limited, but is preferably 1 to 100 μm, more preferably 2 to 80 μm, still more preferably 3 to 60 μm, and particularly preferably 5 to 50 μm.

  The coefficient of variation CV of the particle size distribution of the heat-expandable microspheres is not particularly limited, but is preferably 35% or less, more preferably 30% or less, and particularly preferably 25% or less. The variation coefficient CV is calculated by the following calculation formulas (1) and (2).

(Wherein, s is the standard deviation of the particle size, <x> is an average particle size, x _i is the i-th particle diameter, n is the number of particles.)
The encapsulating rate of the foaming agent encapsulated in the heat-expandable microspheres is not particularly limited, but is preferably 2 to 60% by weight, preferably 5 to 50% by weight, more preferably based on the weight of the heat-expandable microspheres. Is 8 to 45% by weight, particularly preferably 10 to 40% by weight.

The maximum expansion ratio of the thermally expandable microsphere is not particularly limited, but is preferably 20 times or more, more preferably 25 times or more, further preferably 30 times or more, particularly preferably 35 times or more, and most preferably 40 times or more. is there. The upper limit of the maximum expansion ratio of the thermally expandable microsphere is 200 times.
The maximum expansion temperature of the thermally expandable microsphere is not particularly limited, but is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, further preferably 120 ° C. or higher, particularly preferably 130 ° C. or higher, and most preferably 140 ° C. or higher. is there. The upper limit of the maximum expansion temperature of the thermally expandable microsphere is 350 ° C.

The thermally expandable microsphere contains a straight-chain hydrocarbon (A) having 13 or more carbon atoms and an ester (B) represented by the following general formula (1), and the total of these two components (A + B) is the above-mentioned heat. The weight ratio of the expandable microspheres is 0.05 to 3% by weight.
R ¹ COOR ² (1)
(However, R ¹ and R ² are linear hydrocarbon groups, which may be the same or different.)

The straight chain hydrocarbon (A) may be any hydrocarbon that forms a single chain in which the carbon-carbon bond has no branching or cyclic structure. The straight chain hydrocarbon (A) may be an n-alkene, n-alkadiene, n-alkyne or the like having a carbon-carbon double bond or triple bond, but is composed of only a carbon-carbon single bond. n-Alkane is preferred.
The carbon number of the linear hydrocarbon (A) is usually 13 or more, preferably 14 or more, more preferably 15 or more, particularly preferably 16 or more, and most preferably 20 or more. The upper limit of the carbon number of the straight chain hydrocarbon (A) is 50.

Specific examples of the linear hydrocarbon (A) include n-alkanes represented by the following general formula (2).
n-C _2X H _{4X + 2} (2)
(However, X is a number from 7 to 18.)

Here, X is usually 7 to 18, preferably 8 to 17, more preferably 10 to 16, and particularly preferably 11 to 15. When X is less than 7, the thermoplastic resin constituting the outer shell (hereinafter sometimes referred to as outer shell resin) lacks flexibility and dynamic durability may be insufficient. If X is more than 18, the outer shell resin is plasticized, the retention of the foaming agent contained in the outer shell becomes insufficient, and the dynamic durability may be insufficient.
Next, R ¹ and R ² of the ester (B) are straight-chain hydrocarbon groups, and the carbon-carbon bond is a hydrocarbon group that forms a single chain having no branching or cyclic structure. Good. R ¹ and R ² may be n-alkenyl, n-alkadienyl, n-alkynyl or the like having a carbon-carbon double bond or triple bond, but are composed of only a carbon-carbon single bond. n-alkyl is preferred.

The number of carbon atoms of the ester (B) is not particularly limited, but is preferably 10 or more, more preferably 12 or more, particularly preferably 18 or more, and most preferably 20 or more. The upper limit of the carbon number of the ester (B) is 101. In addition, the carbon number of ester (B) means the number of all carbons contained in ester (B).
The ester (B) is preferably an ester of a linear saturated fatty acid and a linear saturated alcohol, and examples thereof include a compound represented by the following general formula (3).

n-C _Y H _{2Y + 1} COO (n-C _Z H _{2Z + 1} ) (3)
(However, Y is a number from 6 to 18, and Z is a number from 6 to 18.)
Here, Y is usually 6-18, preferably 7-17, more preferably 10-16, and particularly preferably 11-15. If Y is less than 6, the outer shell resin may lack flexibility and dynamic durability may be insufficient. On the other hand, if Y is more than 18, the outer shell resin is plasticized, the retention of the foaming agent contained in the outer shell becomes insufficient, and the dynamic durability may be insufficient.

Z is usually 6 to 18, preferably 7 to 17, more preferably 10 to 16, and particularly preferably 11 to 15. If Z is less than 6, the outer shell resin may lack flexibility and dynamic durability may be insufficient. On the other hand, when Z is more than 18, the outer shell resin is plasticized, the retention of the foaming agent contained in the outer shell becomes insufficient, and the dynamic durability may be insufficient.
From the correspondence relationship of the general formula (1) and the general formula (3), there is a relationship of R ¹ = n−C _Y H _{2Y + 1} and R ² = n−C _Z H _{2Z + 1} .

The mutual relationship between X, Y and Z is not particularly limited, but the absolute value | X−Y | of the difference between X and Y, the absolute value | Y−Z | of the difference between Y and Z, and Z The absolute value | Z−X | of the difference between X and X is preferably 3 or less, more preferably 2 or less, particularly preferably 1 or less, and most preferably 0. If the absolute value exceeds 3, the dispersibility of the linear hydrocarbon (A) in the outer shell resin becomes non-uniform due to the action of the ester (B), and the flexibility of the outer shell resin becomes non-uniform. Inferred and dynamic durability may be insufficient.
X, Y and Z are all preferably in the range of 7 to 17, more preferably 10 to 16, and particularly preferably 11 to 15.

The weight ratio of the total of two components of the linear hydrocarbon (A) and the ester (B) (A + B) to the thermally expandable microsphere is usually 0.05 to 3% by weight, preferably 0.075 to 2% by weight. %, More preferably 0.10 to 1.5% by weight, particularly preferably 0.12 or more and less than 1% by weight. When the total weight ratio of the two components is less than 0.05% by weight, the outer shell resin lacks flexibility and dynamic durability is insufficient. On the other hand, if the total weight ratio of the two components is more than 3% by weight, the outer shell resin is plasticized, the retention of the foaming agent becomes insufficient, and the dynamic durability is insufficient.
The weight ratio (A / B) between the linear hydrocarbon (A) and the ester (B) is not particularly limited, but is preferably 35/65 to 80/20, more preferably 40/60 to 70/30. Particularly preferred is 50/50 to 65/35. When A / B is smaller than 35/65, the outer shell resin is plasticized, the retention of the foaming agent becomes insufficient, and the dynamic durability may be insufficient. On the other hand, when A / B is larger than 80/20, the flexibility of the outer shell resin becomes uneven, and dynamic durability may be insufficient.

The blowing agent is a substance that is vaporized by heating, and is not particularly limited as long as it is a hydrocarbon having 3 to 12 carbon atoms. The hydrocarbon preferably has 4 to 10 carbon atoms, more preferably 5 to 8 carbon atoms. It is. Examples of the blowing agent include propane, (iso) butane, (iso) pentane, (iso) hexane, (iso) heptane, (iso) octane, (iso) nonane, (iso) decane, and (iso) dodecane. Can be mentioned. These foaming agents may be used alone or in combination of two or more. The foaming agent may be linear, branched or alicyclic, and is preferably aliphatic.
In order to expand the heat-expandable microspheres by heating, together with the above blowing agent, a halide having 3 to 12 carbon atoms; a fluorine-containing compound such as hydrofluoroether; tetraalkylsilane; You may use a compound etc. together.

The thermoplastic resin forming the outer shell of the thermally expandable microsphere is obtained by polymerizing a polymerizable component (preferably in the presence of a polymerization initiator). The polymerizable component is a component which essentially includes a monomer component and may contain a crosslinking agent.
The monomer component generally includes a component called a (radical) polymerizable monomer having one polymerizable double bond.

The monomer component is not particularly limited. For example, nitrile monomers such as acrylonitrile, methacrylonitrile, and fumaronitrile; vinyl halide monomers such as vinyl chloride; vinylidene halides such as vinylidene chloride Monomers; carboxyl group-containing monomers such as acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid, itaconic acid, fumaric acid, citraconic acid, chloromaleic acid; anhydrides of carboxyl group-containing monomers; Vinyl ester monomers such as vinyl acetate, vinyl propionate and vinyl butyrate; methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl ( (Meth) acrylate, stearyl (meth) acrylate, phenyl (meth) (Meth) acrylic acid ester monomers such as acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate; (meth) acrylamide, substituted (meth) (Meth) acrylamide monomers such as acrylamide; maleimide monomers such as N-phenylmaleimide and N-cyclohexylmaleimide; styrene monomers such as styrene and α-methylstyrene; ethylene, propylene, isobutylene and the like Ethylenically unsaturated monoolefin monomers; vinyl ether monomers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketone monomers such as vinyl methyl ketone; N-vinyl carbazole, N-vinyl pyrrolidone And N-vinyl monomers such as vinyl naphthalene salts. In addition, (meth) acryl means acryl or methacryl.
Monomer component includes nitrile monomer, carboxyl group-containing monomer, (meth) acrylic acid ester monomer, styrene monomer, vinyl ester monomer, (meth) acrylamide single monomer And at least one selected from vinylidene halide monomers.

The thermoplastic resin is composed of a copolymer obtained by polymerizing a monomer component containing a nitrile monomer, and the weight ratio of the nitrile monomer in the monomer component is preferably 80% by weight. % Or more, more preferably 90% by weight or more, still more preferably 95% by weight or more, and particularly preferably 98% by weight or more, because the gas barrier property of the thermoplastic resin constituting the outer shell is improved. The upper limit of the weight ratio of the nitrile monomer is 100% by weight.
The polymerizable component may contain a polymerizable monomer (crosslinking agent) having two or more polymerizable double bonds in addition to the monomer component. By polymerizing using a crosslinking agent, a decrease in the retention rate (encapsulation retention rate) of the encapsulated foaming agent at the time of thermal expansion is suppressed, and thermal expansion can be effectively performed.

Although it does not specifically limit as a crosslinking agent, For example, aromatic divinyl compounds, such as divinylbenzene; Allyl methacrylate, triacryl formal, triallyl isocyanate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1 , 4-butanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, PEG # 200 di (meth) acrylate, PEG # 600 di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Di (meth) acrylate compounds such as pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, etc. Give Door can be. These crosslinking agents may be used alone or in combination of two or more. In addition, (meth) acrylate means an acrylate or a methacrylate.
The amount of the crosslinking agent is not particularly limited, but is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, and particularly preferably 0. 15 to 0.8 parts by weight.

Examples of the method for producing thermally expandable microspheres of the present invention include an aqueous dispersion in which an oily mixture containing the polymerizable component, the foaming agent, the linear hydrocarbon (A) and the ester (B) described above is dispersed. A method of polymerizing a polymerizable component in a medium can be mentioned. The manufacturing method of the thermally expandable microsphere may be anything other than this manufacturing method. In the method for producing the thermally expandable microsphere, for example, polymerization is carried out without containing the linear hydrocarbon (A) and the ester (B) in the oily mixture, and the linear hydrocarbon (A) and the ester ( B) may be produced by some kind of reaction.
The thermally expandable microsphere may have a fine particle filler attached to its outer shell. In the heat-expandable microsphere, when the fine particle filler adheres to the outer surface of the outer shell, the dispersibility and fluidity during use are improved. In addition, when hollow microparticles obtained by heating and expanding thermally expandable microspheres (hereinafter referred to as microparticle-attached thermally expandable microspheres) having a particulate filler attached to the outer surface of the outer shell are used as a lightweight filler. In addition, the dispersibility can be improved.

The fine particle filler may be either an organic or inorganic filler, and the type and amount thereof are appropriately selected according to the purpose of use.
Examples of organic fillers include metal soaps such as magnesium stearate, calcium stearate, zinc stearate, barium stearate, lithium stearate; polyethylene wax, lauric acid amide, myristic acid amide, palmitic acid amide, stearic acid Synthetic waxes such as amide and hardened castor oil; resin powders such as polyacrylamide, polyimide, nylon, polymethyl methacrylate, polyethylene, and polytetrafluoroethylene.

Examples of inorganic fillers include talc, mica, bentonite, sericite, carbon black, molybdenum disulfide, tungsten disulfide, fluorinated graphite, calcium fluoride, boron nitride, etc .; others, silica, alumina, mica, colloidal Examples include calcium carbonate, heavy calcium carbonate, calcium hydroxide, calcium phosphate, magnesium hydroxide, magnesium phosphate, barium sulfate, titanium dioxide, zinc oxide, ceramic beads, glass beads, and crystal beads. The inorganic filler may be surface-treated with a fatty acid, a fatty acid metal salt, a fatty acid amide, a fatty acid ester, a silane coupling agent, a wax or the like.
These fine particle fillers may be used alone or in combination of two or more. When the heat-expandable microspheres with fine particles attached are used for applications where elongation properties are important, such as an elastic adhesive, a sealing material, a body sealer, and a paint, it is preferable that the elongation properties are not easily impaired.

In the method for producing thermally expandable microspheres, it is preferable to polymerize a polymerizable component in the presence of a polymerization initiator using an oily mixture containing a polymerization initiator. In the following description of the manufacturing method, various explanations regarding the above-described thermally expandable microspheres may be applied as they are unless otherwise noted in order to avoid duplication.
Although there is no limitation in particular as a polymerization initiator, A peroxide, an azo compound, etc. can be mentioned.

Examples of the peroxide include diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-octyl peroxydicarbonate, and dibenzyl peroxydicarbonate. Peroxydicarbonates such as t-butyl peroxypivalate, t-hexyl peroxypivalate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-butylperoxy 3,5,5-trimethyl Peroxyesters such as hexanoate; isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, caproyl peroxide, lauroyl peroxide, stearoyl peroxide, benzene Yl diacyl peroxide of peroxide and the like, and the like.
Examples of the azo compound include 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4- Dimethylvaleronitrile), 2,2'-azobis (2-methylpropionate), 2,2'-azobis (2-methylbutyronitrile), and the like. Among the polymerization initiators, peroxydicarbonate is preferable.

These polymerization initiators may be used alone or in combination of two or more. As the polymerization initiator, an oil-soluble polymerization initiator soluble in the monomer component is preferable.
Although there is no limitation in particular about the quantity of a polymerization initiator, it is preferable in it being 0.3-8.0 weight part with respect to 100 weight part of said monomer components.

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 in which the oily mixture is dispersed, and may further contain an alcohol such as methanol, ethanol or propanol, or a hydrophilic organic solvent such as acetone. . The hydrophilicity in the present invention means that it can be arbitrarily mixed with water. Although there is no limitation in particular about the usage-amount of an aqueous dispersion medium, it is preferable to use 100-1000 weight part aqueous dispersion medium with respect to 100 weight part of polymeric components.

The aqueous dispersion medium may further contain an electrolyte. Examples of the electrolyte include sodium chloride, magnesium chloride, calcium chloride, sodium sulfate, magnesium sulfate, ammonium sulfate, and sodium carbonate. These electrolytes may be used alone or in combination of two or more. Although there is no limitation in particular about content of an electrolyte, it is preferable to contain 0.1-50 weight part with respect to 100 weight part of aqueous dispersion media.
An 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 hetero atom are bonded to the same carbon atom , Potassium dichromate, alkali metal nitrite, metal (III) halide, boric acid, water-soluble ascorbic acids, water-soluble polyphenols, water-soluble vitamin Bs and water-soluble phosphonic acids (salts) It may contain at least one water-soluble compound. In addition, the water solubility in this invention means the state which melt | dissolves 1g or more per 100g of water.

The amount of the water-soluble compound contained in the aqueous dispersion medium is not particularly limited, but is preferably 0.0001 to 1.0 part by weight, more preferably 0.0003 to 100 parts by weight of the polymerizable component. 0.1 parts by weight, particularly preferably 0.001 to 0.05 parts by weight. If the amount of the water-soluble compound is too small, the effect of the water-soluble compound may not be sufficiently obtained. Moreover, when there is too much quantity of a water-soluble compound, a polymerization rate may fall or the residual amount of the polymeric component which is a raw material may increase.
The aqueous dispersion medium may contain a dispersion stabilizer and a dispersion stabilization auxiliary agent in addition to the electrolyte and the water-soluble compound.

The dispersion stabilizer is not particularly limited. For example, colloidal silica, colloidal calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, ferric hydroxide, calcium sulfate, barium sulfate, calcium oxalate, metasilicic acid. Calcium, calcium carbonate, barium carbonate, magnesium carbonate, calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, etc. phosphates, calcium pyrophosphate, aluminum pyrophosphate, pyrophosphates such as zinc pyrophosphate, difficulties such as alumina sol The dispersion stabilizer of a water-soluble inorganic compound can be mentioned. These dispersion stabilizers may be used alone or in combination of two or more.
The blending amount of the dispersion stabilizer is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the polymerizable component.

The dispersion stabilizing aid is not particularly limited, and examples thereof include a polymer type dispersion stabilizing aid, a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant. Mention may be made of activators. These dispersion stabilizing aids may be used alone or in combination of two or more.
The aqueous dispersion medium is prepared, for example, by blending water (ion-exchanged water) with a water-soluble compound and, if necessary, a dispersion stabilizer and / or a dispersion stabilizing aid. The pH of the aqueous dispersion medium at the time of polymerization is appropriately determined depending on the type of the water-soluble compound, the dispersion stabilizer, and the dispersion stabilization aid.

The oily mixture is usually emulsified and dispersed in an aqueous dispersion medium so that spherical oil droplets having a predetermined particle diameter are prepared. Examples of the method for emulsifying and dispersing the oily mixture include, for example, a method of stirring with a homomixer (for example, manufactured by Tokushu Kika Kogyo Co., Ltd.) and the like, and a static dispersion device such as a static mixer (for example, manufactured by Noritake Engineering Co., Ltd.). And general dispersion methods such as a method using a film, a membrane emulsification method, and an ultrasonic dispersion method.
Next, suspension polymerization is started by heating the dispersion in which the oily mixture is dispersed as spherical oil droplets in the aqueous dispersion medium. During the polymerization reaction, it is preferable to stir the dispersion, and the stirring may be performed so gently as to prevent, for example, floating of the monomer and sedimentation of the thermally expandable microspheres after polymerization.

Although superposition | polymerization temperature is freely set by the kind of polymerization initiator, Preferably it is 30-100 degreeC, More preferably, it controls in the range of 40-90 degreeC. The time for maintaining the reaction temperature is preferably about 0.1 to 20 hours. Although there is no limitation in particular about the superposition | polymerization initial pressure, it is the range of 0-5.0 MPa by gauge pressure, More preferably, it is the range of 0.1-3.0 MPa.
In the method for producing fine particle-adhering thermally expandable microspheres, the fine particle filler can be adhered by mixing the thermally expandable microspheres and the fine particle filler before adhesion. The mixing is not particularly limited, and can be performed using an apparatus having a very simple mechanism such as a container and a stirring blade. Moreover, you may use the powder mixer which can perform a general rocking | swiveling or stirring. Examples of the powder mixer include a powder mixer that can perform rocking stirring or stirring, such as a ribbon mixer and a vertical screw mixer. In recent years, super mixers (made by Kawata Co., Ltd.), high-speed mixers (made by Fukae Co., Ltd.) and Negura Machine (made by Seishin Enterprise Co., Ltd.), which are efficient and multifunctional powder mixers combined with a stirring device ), SV mixer (manufactured by Shinko Environmental Solution Co., Ltd.) or the like may be used.

  The amount of the fine particle filler adhering to the thermally expandable microsphere is not particularly limited, but the function of the fine particle filler can be sufficiently exerted, and considering the size of the true specific gravity of the thermally expandable microsphere, etc. Is preferably 0.1 to 95 parts by weight, more preferably 0.5 to 60 parts by weight, particularly preferably 5 to 50 parts by weight, and most preferably 8 to 30 parts by weight per 100 parts by weight of the thermally expandable microspheres. Part.

[Use of thermally expandable microspheres]
The hollow fine particles of the present invention can be obtained by heating and expanding the above heat-expandable microspheres. The method of heating expansion is not particularly limited as long as it includes a step of heating to a temperature at which the thermally expandable microsphere expands or higher, and either a dry heating expansion method or a wet heating expansion method may be used.
There are no particular limitations on the temperature for thermal expansion as long as the thermally expandable microspheres are above the expansion start temperature and below the maximum expansion temperature. The temperature is preferably 80 to 350 ° C, more preferably 100 to 300 ° C, and particularly preferably 120 to 250 ° C.

Examples of the dry heating expansion method include a method described in JP-A-2006-213930, particularly an internal injection method (particularly, the 0057th paragraph to the 0080th paragraph). As another dry heating expansion method, there are a method described in JP-A-3-273037 and JP-A-2006-96963. Examples of the wet heating expansion method include the method described in JP-A No. 62-201231.
As described in detail in the background art above, the repeated compression durability measured in Patent Document 6 means the durability of hollow fine particles against “static pressure changes” in which pressurization and depressurization are repeated at a moderate rate. To do. However, in situations where hollow microparticles are actually used in various ways, it is rare to receive only such a “static pressure change”, and “dynamics” in which pressurization and depressurization are repeatedly performed at a high speed in a short time. Are often subject to “changes in pressure”. The hollow fine particles of the present invention have excellent durability against dynamic pressure changes (excellent dynamic durability). Moreover, when hollow fine particles are mixed, transferred to a pipe, filled, etc., it is difficult to increase the specific gravity.

The dynamic durability (D _dyn ) of the hollow fine particles is measured by the method described in detail in Examples. The dynamic durability is preferably 0.06 or less, more preferably 0.05 or less, further preferably 0.04 or less, particularly preferably 0.03 or less, and most preferably 0.02 or less. A preferred lower limit of dynamic durability is zero. When the dynamic durability exceeds 0.06, the durability against the dynamic pressure change is small, and even when the pressure is completely removed after the measurement of the dynamic durability, it is difficult to restore the spherical shape. Further, when the dynamic durability of the hollow fine particles is low, the specific gravity may be larger than the assumed specific gravity when the hollow fine particles are mixed, transferred to a pipe, filled, or the like.
Although there is no limitation in particular about the average particle diameter of a hollow microparticle, Preferably it is 1-1000 micrometers, More preferably, it is 5-800 micrometers, Most preferably, it is 10-500 micrometers. Further, the coefficient of variation CV of the particle size distribution of the hollow fine particles is not particularly limited, but is preferably 30% or less, more preferably 27% or less, and particularly preferably 25% or less.

The thickness of the outer shell made of the thermoplastic resin in the hollow fine particles is not particularly limited, but is preferably 0.05 to 1.0 μm, more preferably 0.1 to 0.7 μm, and particularly preferably 0.15 to 0.15 μm. 0.5 μm. The film thickness of the outer shell can be measured by observing the cross section of the hollow fine particles with an electron microscope.
The true specific gravity of the hollow fine particles is not particularly limited, but is preferably 0.010 to 0.5, more preferably 0.015 to 0.3, and particularly preferably 0.020 to 0.2.

As shown in FIG. 2, the hollow fine particles of the present invention may be further composed of a fine particle filler adhering to the outer surface of the outer shell. Hereinafter, the hollow fine particles may be referred to as fine particle-adhered hollow fine particles.
The term “adhesion” as used herein may simply be the state (6) in which the fine particle fillers (6 and 7) are adsorbed on the outer surface of the outer shell (5) of the fine particle-adhered hollow fine particles (4). This means that the thermoplastic resin constituting the nearby outer shell may be melted by heating, and the fine particle filler may sink into the outer surface of the outer shell of the fine particle-attached hollow fine particles and be fixed (7). The particle shape of the fine particle filler may be indefinite or spherical. In the case of fine particles-attached hollow fine particles, the dispersibility is improved and the fluidity is improved during use, similar to the fine-particle-attached thermally expandable microsphere. Further, when the fine particle-attached hollow fine particles obtained by this production method are used as a light weight filler for elastic adhesives, sealing materials, body sealers, paints, etc., it is difficult to impair the stretch physical properties of the base component.

  The fine particle-attached hollow fine particles can be obtained by heating and expanding the fine particle-attached thermally expandable microspheres. As the fine particle-attached hollow fine particles, a step of mixing thermally expandable microspheres and a fine particle filler (mixing step), and heating the mixture obtained in the mixing step to a temperature above the softening point, the thermal expansion The following production method is preferred, which includes a step of attaching the fine particle filler to the outer surface of the resulting hollow fine particles (attachment step) while expanding the functional microspheres.

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

  As an apparatus used for the mixing step, the production apparatus used in the production method of the fine particle-attached thermally expandable microsphere can be used as it is.

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

The temperature condition for heating depends on the type of the heat-expandable microsphere, but the optimum expansion temperature is preferable, preferably 60 to 250 ° C, more preferably 70 to 230 ° C, and still more preferably 80 to 220 ° C. is there.
The average particle size of the hollow particles with fine particles is not particularly limited, but is preferably 1 to 1000 μm, more preferably 5 to 800 μm, and particularly preferably 10 to 500 μm. Further, the coefficient of variation CV of the particle size distribution of the hollow fine particles is not particularly limited, but is preferably 30% or less, more preferably 27% or less, and particularly preferably 25% or less.

The film thickness of the outer shell made of the thermoplastic resin in the fine particle-attached hollow fine particles is not particularly limited, but is preferably 0.05 to 1.0 μm, more preferably 0.1 to 0.7 μm, and particularly preferably 0.8. 15 to 0.5 μm. The film thickness of the outer shell can be measured by observing the cross section of the hollow fine particles with an electron microscope.
The true specific gravity of the fine particle-attached hollow fine particles is not particularly limited, but is preferably 0.01 to 0.5, more preferably 0.03 to 0.4, and particularly preferably 0.05 to 0.35. Most preferably, it is 0.07-0.30. When the true specific gravity of the fine particles attached hollow fine particles is smaller than 0.01, the durability may be insufficient. On the other hand, when the true specific gravity of the fine particle-adhered hollow fine particles is larger than 0.5, the effect of lowering the specific gravity is reduced. Therefore, when the composition is prepared using the fine particle-adhered hollow fine particles, the amount added is large, which is uneconomical. Sometimes.

The composition of the present invention contains the thermally expandable microspheres and / or hollow fine particles, and a base component. The composition of the present invention is excellent in dynamic durability. When the composition of the present invention contains hollow fine particles as a base component, it is preferable because the weight can be reduced.
The composition of the present invention may be a one-component type. In addition, the composition of the present invention comprises, for example, a liquid A containing a precursor of a base component and a precursor of the base component, like an adhesive composition and a molding composition described in detail below. It may consist of a combination of liquid B containing a curing agent for generating a base material component by curing, and may be a two-liquid type in which the base material component is generated by mixing the liquid A and the liquid B.

The base material component is not particularly limited. For example, rubbers such as natural rubber, butyl rubber, silicone rubber, ethylene-propylene-diene rubber (EPDM); thermosetting resins such as epoxy resin and phenol resin; polyethylene wax, paraffin Waxes such as wax; ethylene-vinyl acetate copolymer (EVA), ionomer, polyethylene, polypropylene, polyvinyl chloride (PVC), acrylic resin, thermoplastic polyurethane, acrylonitrile-styrene copolymer (AS resin), acrylonitrile- Thermoplastic resins such as butadiene-styrene copolymer (ABS resin) and polystyrene (PS); Thermoplastic elastomers such as olefin elastomer and styrene elastomer; Bioplastics such as polylactic acid (PLA) and starch resin; Silico Emissions, modified silicone, polyurethane, polysulfide, acrylic rubber, the sealing material of polyisobutylene; urethane, ethylene - vinyl acetate copolymer-based, vinyl chloride, and a coating component such as an acrylic.
The substrate component may be an inorganic substance. Examples of such inorganic substances include ordinary portland cement, early-strength cement, alumina cement, blast furnace slag cement, fly ash cement, mortar, and other cements; slag such as blast furnace slag, electric furnace oxidation slag, and electric furnace reduction slag; Lime such as quicklime and slaked lime; titania, alumina, zirconia, silica, magnesia, zircon, barium zirconate, lead titanate, barium titanate, mullite, zinc oxide, tin oxide, silicon carbide, silicon nitride, ferrite, cordierite Ceramics such as: Limestone (heavy calcium carbonate), quartz, quartzite (silica), wollastonite, gypsum, apatite, magnetite, zeolite, clay (montmorillonite, saponite, hectorite, beidellite, stevensite, nontronite, bar Minerals such as curite, halloysite, talc, mica, mica, etc .; in the periodic table of elements, metal oxides (titanium oxide, zinc oxide, aluminum oxide, manganese oxide, each having a metal belonging to Group 1 to Group 16; Molybdenum oxide, tungsten oxide, vanadium oxide, tin oxide, iron oxide (including magnetic iron oxide, indium oxide, etc.), metal hydroxide (aluminum hydroxide, gold hydroxide, magnesium hydroxide, etc.), metal carbonate ( Calcium carbonate (light calcium carbonate), calcium hydrogen carbonate, sodium hydrogen carbonate (bicarbonate), iron carbonate, etc.), sulfate metal salts (aluminum sulfate, cobalt sulfate, sodium hydrogen sulfate, copper sulfate, nickel sulfate, barium sulfate, etc.), others Metal salts (titanates (barium titanate, magnesium titanate, potassium titanate Etc.), borate (aluminum borate, zinc borate, etc.), phosphates (calcium phosphate, sodium phosphate, magnesium phosphate, etc.), nitrates (sodium nitrate, iron nitrate, lead nitrate, etc.) But you can. These inorganic substances may be used alone or in combination of two or more.

Since the hollow fine particles of the present invention are excellent in dynamic durability, when the base material component is at least one inorganic material selected from cements, cordierite and silicon carbide, they are mixed and molded with the hollow fine particles at room temperature. Further, it is preferable that the hollow base particles are not destroyed and the base material component is further cured by hydration condensation, firing, or the like, so that the pores and the weight can be easily reduced by the voids derived from the hollow fine particles.
The composition of the present invention can be prepared by mixing these base components with thermally expandable microspheres and / or hollow fine particles.

As described above, the hollow fine particles of the present invention are particularly excellent in dynamic durability. For this reason, when preparing the composition containing hollow microparticles, there is little destruction by the dynamic pressure change at the time of mixing. Therefore, there is a difference between the actual specific gravity of the obtained composition and the design specific gravity of the composition obtained by calculation from the specific gravity of each component mixed when it is assumed that no destruction of the hollow fine particles occurs. Not likely to occur. In the composition of the present invention containing hollow fine particles, the ratio of the specific gravity of the actually obtained composition to the design specific gravity of the composition (specific gravity ratio) is preferably 1.10 times or less, more preferably 1.05 times. Hereinafter, it is particularly preferably 1.03 times or less, most preferably 1.0 times. Here, the specific gravity ratio of 1.0 means that the hollow fine particles are hardly broken. On the other hand, if the specific gravity ratio is greater than 1.10 times, the weight reduction effect may be impaired.
Examples of the use of the composition of the present invention include a molding composition, a coating composition, a clay composition, a fiber composition, an adhesive composition, and a powder composition.

When the composition of the present invention is an adhesive composition, it is preferable to contain the sealing material as a base material component together with the hollow fine particles because the weight can be reduced and the influence on the elongation physical properties is small. The weight ratio of the base material component and the hollow fine particles to be blended in the adhesive composition (base material component / hollow fine particles) is not particularly limited, but is preferably 99.995 / 0.005-70 / 30, Preferably it is 99.99 / 0.01-80 / 20, Most preferably, it is 99.95 / 0.05-90 / 10. When the said weight ratio is larger than 99.995 / 0.005, there is a possibility that the amount of hollow fine particles added is small and the effect of weight reduction is diminished. On the other hand, when the said weight ratio is smaller than 70/30, there are few base material components and the function as an adhesive composition falls remarkably. Here, when the adhesive composition is a two-component type, it means the total amount of the base material component precursor contained in the A solution and the curing agent contained in the B solution.
In the adhesive composition, it is more preferable that the hollow fine particles are fine particle-adhered hollow fine particles with little influence on the elongation property. Moreover, it is preferable that the sealing material which is a base material component is modified silicone, polyurethane, polysulfide or the like.

When the adhesive composition is a one-pack type and the sealing material is polyurethane, in the composition containing hollow fine particles and an isocyanate group-containing urethane prepolymer, the isocyanate group reacts with moisture in the air, and the urethane prepolymer is crosslinked and It cures and produces polyurethane, thereby exhibiting adhesiveness.
When the adhesive composition is a two-component type and the sealing material is polyurethane, a solution A (precursor of a base material component) containing a urethane prepolymer and a solution B (curing agent) containing a polyol, hollow fine particles, etc. It consists of two combinations. By mixing the A liquid and the B liquid, the urethane prepolymer is cross-linked and cured, and the polyurethane is produced, thereby exhibiting adhesiveness.

When the adhesive composition is a one-pack type and the sealing material is a modified silicone, in the composition containing hollow fine particles and a crosslinkable silyl group-containing resin, the crosslinkable silyl group-containing resin reacts with moisture in the air to crosslink.・ Adhesiveness is expressed by curing to produce modified silicone.
When the adhesive composition is a two-pack type and the sealing material is a modified silicone, it contains a liquid A containing a siloxane polymer (a precursor of the base material component), a curing agent such as aminoxysiloxane and polyol, and hollow fine particles. It consists of two combinations with B liquid (curing agent). By mixing the A liquid and the B liquid, the siloxane polymer is cross-linked and cured, and the modified silicone is generated to exhibit adhesiveness.

When the adhesive composition is a one-component type and the sealing material is polysulfide, hollow fine particles, liquid polysulfide resin, and peroxides of alkali or alkaline metals such as BaO ₂ and CaO ₂ (latent curing agents) In the composition containing, the liquid polysulfide resin reacts with moisture in the air, and the liquid polysulfide resin is crosslinked / cured to produce polysulfide, thereby exhibiting adhesiveness.
When the adhesive composition is a two-component type and the sealing material is polysulfide, a liquid A containing a sulfide prepolymer (a precursor of a base material component), a metal peroxide curing agent such as PdO ₂ and hollow fine particles, etc. It consists of two combinations with B liquid (curing agent) to contain. By mixing the A liquid and the B liquid, the sulfide prepolymer is cross-linked and cured, and polysulfide is generated, thereby exhibiting adhesiveness.

The composition of the present invention is a compound having a melting point lower than the expansion start temperature of the thermally expandable microsphere and / or a thermoplastic resin (for example, polyethylene wax, paraffin wax, in particular, as a base component together with the thermally expandable microsphere. Waxes such as ethylene-vinyl acetate copolymer (EVA), ionomers, polyethylene, polypropylene, polyvinyl chloride (PVC), acrylic resins, etc .; thermoplastic elastomers such as olefin elastomers and styrene elastomers) Can be used as a master batch for resin molding.
In this case, this resin molding masterbatch composition is used for injection molding, extrusion molding, press molding, and the like, and is suitably used for introducing bubbles during resin molding. The resin used at the time of resin molding is not particularly limited as long as it is selected from the above base material components. For example, ethylene-vinyl acetate copolymer (EVA), ionomer, polyethylene, polypropylene, polyvinyl chloride (PVC), Acrylic resin, thermoplastic polyurethane, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polystyrene (PS), olefin elastomer, styrene elastomer, polylactic acid (PLA), Examples thereof include starch resin, natural rubber, butyl rubber, silicone rubber, ethylene-propylene-diene rubber (EPDM), and mixtures thereof. Moreover, you may contain reinforcing fibers, such as glass fiber and carbon fiber.

The molded product of the present invention is obtained by molding this composition. As a molded product of this invention, molded products, such as a molded article and a coating film, can be mentioned, for example. The molded product of the present invention has excellent dynamic durability, and various physical properties such as lightness, porosity, sound absorption, heat insulation, low thermal conductivity, low dielectric constant, design, shock absorption, strength, etc. Has improved.
Since the molded product of the present invention is obtained by molding the above composition, it is lightweight and has excellent dynamic durability.
A ceramic filter or the like can be obtained by further firing a molded product containing an inorganic substance as a base component.

Examples of the present invention will be specifically described below. The present invention is not limited to these examples. In the following Examples and Comparative Examples, “%” means “% by weight” unless otherwise specified.
About an Example and a comparative example, various physical properties and performance were measured and evaluated in the way shown below.

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

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

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

[Measurement of expansion start temperature (Ts) and maximum expansion temperature (Tmax)]
As a measuring device, DMA (DMA Q800 type, manufactured by TA instruments) was used. 0.5 mg of thermally expandable microspheres are placed in an aluminum cup having a diameter of 6.0 mm (inner diameter 5.65 mm) and a depth of 4.8 mm, and an aluminum lid (diameter 5.6 mm, thickness 0) is placed on top of the thermally expandable microsphere layer. .1 mm) to prepare a sample. The sample height was measured in a state where a force of 0.01 N was applied to the sample with a pressurizer from above. In a state where a force of 0.01 N was applied by the pressurizer, the plate was heated from 20 ° C. to 300 ° C. at a temperature rising rate of 10 ° C./min, and the displacement of the pressurizer in the vertical direction was measured. The displacement start temperature in the positive direction was defined as the expansion start temperature (Ts), and the temperature when the maximum displacement was indicated was defined as the maximum expansion temperature (Tmax).

[Measurement of content of hydrocarbon (A) and ester (B)]
0.5 g of thermally expandable microspheres and 20 ml of n-hexane were mixed, stirred for 30 minutes, and then filtered to take out thermally expandable microspheres. After repeating this operation three times, the thermally expandable microspheres were dried to prepare washed thermally expandable microspheres. After adding 0.1 g of the washed thermally expandable microspheres and 5 ml of DMF to a vial with a capacity of 20 ml, the vial is covered with a septum cap, and the thermally expandable microspheres are swollen with DMF at 23 ° C. for 24 hours. I let you. Next, 5 ml of acetone was further added to the vial, mixed and allowed to stand at 23 ° C. for 2 hours. GC-MS analysis (FID method, manufactured by Agilent, 7890A GC) was performed using 1 μl of the supernatant as a sample, and hydrocarbon (A) And the content of ester (B) were measured.

[Measurement of true specific gravity]
The true specific gravity of particles such as thermally expandable microspheres and hollow fine particles was measured by the following measuring method.
The true specific gravity was measured by an immersion method (Archimedes method) using isopropyl alcohol in an atmosphere having an environmental temperature of 25 ° C. and a relative humidity of 50%.
Specifically, the volumetric flask having a capacity of 100 cc was emptied and dried, and the weight of the volumetric flask (WB ₁ ) was weighed. After the weighed volumetric flask was accurately filled with isopropyl alcohol to the meniscus, the weight (WB ₂ ) of the volumetric flask filled with 100 cc of isopropyl alcohol was weighed.
Further, the volumetric flask with a capacity of 100 cc was emptied and dried, and the weight of the volumetric flask (WS ₁ ) was weighed. The weighed volumetric flask was filled with about 50 cc of particles, and the weight (WS ₂ ) of the volumetric flask filled with the particles was weighed. Then, the weight (WS ₃ ) after accurately filling the meniscus with isopropyl alcohol so that bubbles do not enter into the volumetric flask filled with particles was weighed. Then, the obtained WB ₁ , WB ₂ , WS ₁ , WS ₂ and WS ₃ were introduced into the following equation, and the true specific gravity (d) of the particles was calculated.
d = {(WS ₂ −WS ₁ ) × (WB ₂ −WB ₁ ) / 100} / {(WB ₂ −WB ₁ ) − (WS ₃ −WS ₂ )}

[Dynamic durability of hollow fine particles]
As described above, the internal injection method described in Japanese Patent Application Laid-Open No. 2006-213930 was adopted as a method for producing the hollow fine particles used for measuring the dynamic durability. Specifically, using the manufacturing apparatus provided with the foaming process part shown in FIG.

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

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

(Method for setting manufacturing conditions for hollow fine particles)
First, parameters such as the supply amount of the heat-expandable microspheres that are raw materials, the flow rate of hot air and the amount of raw material dispersed gas are fixed, and the temperature of the hot air flow (hereinafter sometimes referred to as “hot air temperature”) is changed. . Next, while changing the hot air temperature stepwise and fixing other parameters constant, the thermally expandable microspheres were expanded at each temperature, and the true specific gravity of the obtained microspheres was measured, and the hot air temperature ( A graph in which the relationship between the x axis) and the true specific gravity (y axis) is plotted is created.
Moreover, when manufacturing hollow microparticles having a desired true specific gravity ((0.030 ± 0.002) g / cc), the hot air temperature corresponding to the desired true specific gravity in the above graph is set. In this way, the expansion conditions are controlled, and hollow fine particles having a true specific gravity of (0.030 ± 0.002) g / cc are produced.
About the obtained hollow microparticles, the dynamic durability is measured by the following method.

(Measurement of dynamic durability)
The hollow particles having a true specific gravity of (0.030 ± 0.002) g / cc obtained above were allowed to elapse for 24 hours in an environment of 23 ° C. and 50% RH, and then the dynamic durability was measured. .
As a dynamic durability measuring device, a powder viscoelasticity measuring device described in JP-A-2005-257600 is used. Specifically, as shown in FIG. 4, a container (22) containing hollow fine particles (21), and a piston (23) at a position facing the container (22) on the same line are installed, The container (22) can be advanced and retracted toward the piston (23) via the hydraulic cylinder (24) and the support base (25). Accordingly, the container (22) can impart vertical vibration on the same axis to the hollow fine particles (21). The piston (23) is provided with a temperature sensor (30) and a pressure sensor (31) so that the pressure (surface pressure) at the contact surface with the hollow fine particles (21) can be measured.

The container (22) is placed in the thermostatic chamber (26), and the thermostatic chamber (26) is controlled to a constant temperature by the heater (27) and the inert gas (29) by the internal temperature sensor (28). This stabilizes the measurement environment.
Further, at the bottom of the container (22), the container (22) is advanced toward the piston (23) by the hydraulic cylinder (24), and the hollow fine particles (21) in the container (22) are transferred to the container (22). And a filter (32) for removing air contained in the hollow fine particle layer out of the container (22) when compressed between the bottom of the tube and the piston (23).

The measurement conditions for dynamic durability will be specifically described. 66 cc of hollow fine particles was put into a container (inner diameter Φ40 mm, depth 53 mm, bottom filter Φ30 mm, filtration accuracy 20 μm wire mesh sintered filter). Next, when the container is moved upward by a hydraulic cylinder, the hollow fine particles are compressed between the bottom of the container and the fixed piston, and the pressure (surface pressure) of the surface where the hollow fine particles contact the piston is 30 kPa The thickness H ₀ (mm) of the hollow fine particle layer in the container was measured. The hollow fine particles were further compressed, and the thickness H (mm) of the layer of the hollow fine particles in the container when the surface pressure at which the hollow fine particles contact the piston was 100 kPa. And the container was vibrated up and down so that the thickness (mm) of the layer of hollow microparticles may change at a frequency of 10 Hz in the range of (H−0.05H ₀ ) to H.
When the thickness (static displacement) of the hollow fine particle layer in the container when the surface pressure is 100 kPa is set to H ₁₅₀ (mm) and H ₅₀₀ (mm) after 150 seconds and 500 seconds from the start of vibration, the durability _{D dyn} was calculated according to the following equation.

D _dyn = (H ₁₅₀ −H ₅₀₀ ) / H ₀
In addition, when the hollow fine particles are fine particles-adhered hollow fine particles, it may be difficult to produce by the internal injection method described above, so the fine particle-adhered hollow fine particles were produced as follows.

25 g of heat-expandable microspheres and 75 g of heavy calcium carbonate (manufactured by Asahi Kogyo, MC-120) were mixed and added to a 2 L separable flask previously heated to 90-110 ° C. with a mantle heater. Next, the mixture was stirred at a speed of 600 rpm using a stirring blade of polytetrafluoroethylene (length: 150 mm) so that the true specific gravity became (0.12 ± 0.03) g / cc in about 5 minutes. The heating temperature was set to prepare fine particle-attached hollow fine particles. The dynamic durability of the obtained fine particle-attached hollow fine particles was measured according to the above method.
When the hollow fine particles are fine particles-attached hollow fine particles, the hollow fine particles are produced so that the true specific gravity is (0.12 ± 0.03) g / cc, and otherwise, the true specific gravity is (0. 030 ± 0.002) g / cc, but the degree of expandability is almost the same.

[Example 1]
After adding 120 g of sodium chloride, 100 g of colloidal silica 20% by weight of silica active ingredient, 1.0 g of polyvinylpyrrolidone and 1.0 g of 5% aqueous solution of carboxymethylated polyethyleneimine / Na salt to 600 g of ion-exchanged water, The pH of the resulting mixture was adjusted to 2.8 to 3.2 to prepare an aqueous dispersion medium.
Separately, 130 g of acrylonitrile, 107 g of methacrylonitrile, 3 g of methyl methacrylate (above, monomer component); 1.0 g of ethylene glycol dimethacrylate, 0.5 g of trimethylolpropane trimethacrylate (above, cross-linking agent); normal tetradecane 1.0 g, normal heptyl caprylate 1.5 g (above, oil-based additive); isopentane 20 g (foaming agent); and azobisisobutyronitrile 3 g (polymerization initiator) were mixed to prepare an oily mixture. .
The aqueous dispersion medium and the oily mixture were mixed, and the obtained mixed liquid was dispersed for 2 minutes with a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd., TK homomixer, rotation speed: 12000 rpm) to prepare a suspension. The suspension was transferred to a pressure reactor having a capacity of 1.5 liters, and purged with nitrogen. Then, the initial reaction pressure was 0.5 MPa, and polymerization was performed at a polymerization temperature of 70 ° C. for 20 hours while stirring at 80 rpm. The polymer solution obtained after the polymerization was filtered and dried to obtain thermally expandable microspheres. Table 1 shows the physical properties of the obtained thermally expandable microspheres.

[Examples 2 to 8 and Comparative Examples 1 to 4]
Example 1 except that the aqueous dispersion medium, monomer component, crosslinking agent, oil-based additive, foaming agent and polymerization initiator used in Example 1 and the reaction temperature are changed to those shown in Table 1. Similarly, thermally expandable microspheres were obtained. The physical properties are shown in Table 1.
In Table 1, the abbreviations shown in Table 2 below are used.

Example 9
(1 liquid type adhesive composition)
1.7 g of fine particles attached hollow fine particles (average particle size 30 μm, true specific gravity 0.13 g / cc) prepared for dynamic durability evaluation of the thermally expandable microspheres obtained in Example 3, and one-component type modification 100 g of a silicone sealant (Sikaflex-M1, Nippon Seika, specific gravity 1.40) was premixed. Thereafter, the resulting mixture was stirred and degassed for 150 seconds under the rotation conditions of 500 rpm rotation and 2000 rpm revolution using a conditioning mixer (AR-360 manufactured by Sinky Corporation) to obtain an adhesive composition. It was. The physical properties of the obtained adhesive composition were evaluated by the method described in JIS A 1439. The specific gravity was 1.20 (design specific gravity 1.20), and the tensile adhesiveness of the specimen using an aluminum plate as the adherend. The elongation at the maximum load in the test was 480%.

Example 10
(2-pack type adhesive composition)
500 g of liquid A (bond UP seal gray base component, specific gravity 1.0) of a two-component type urethane sealant (bond UP seal gray, manufactured by Konishi) was prepared. Next, the fine particle-attached hollow fine particles used in Example 9 and 2000 g of a curing agent (bond UP seal gray curing agent component, specific gravity 1.50) were added to a mixing stirrer (Dalton, 5DMV-r type, hook blade). Then, after stirring and mixing for 1 hour under the rotation conditions of the rotation speed of 288 rpm and the revolution speed of 135 rpm, a liquid B was obtained.
Subsequently, A liquid was added to B liquid, and it mixed for 15 minutes on the same rotation conditions, and obtained the adhesive composition. When the physical properties of the obtained adhesive composition were measured in the same manner as in Example 9, the specific gravity was 1.02 (design specific gravity 1.00), and the elongation at the maximum load was 430%.

[Comparative Example 5]
In Example 10, 100 g of fine particles adhered hollow fine particles (average particle size 38 μm, true specific gravity 0.13 g / cc) prepared for dynamic durability evaluation of the thermally expandable microspheres obtained in Comparative Example 2 are used. Except for this, an adhesive composition was obtained in the same manner as in Example 10. When the physical properties of the obtained adhesive composition were measured in the same manner as in Example 9, the specific gravity was 1.18 (design specific gravity 1.00), and the elongation at the maximum load was 350%.
When Examples 9 and 10 are compared with Comparative Example 5, the hollow microparticles (fine particle-adhered hollow microparticles) of the present invention are excellent in dynamic durability, and thus are not destroyed even in the production stage of the adhesive composition. It is clear that it contributes to weight reduction of the adhesive composition.

Example 11
(Manufacture of cement composition)
1000 parts by weight of cement, 700 parts by weight of silica, 30 parts by weight of polypropylene fiber, 60 parts by weight of waste paper crushed material, and 25 parts by weight of a cellulose binder are added to a Redige mixer (M20 manufactured by Matsubo) and stirred for 5 minutes. Added and mixed well. Subsequently, 6.2 parts by weight of hollow fine particles (average particle diameter 30 μm, true specific gravity 0.031 g / cc) prepared for dynamic durability evaluation of the thermally expandable microspheres obtained in Example 3 were added, After stirring for an additional minute, water was then sprayed over 2 minutes and mixed. The obtained mixture was transferred to a 10 L double arm kneader (HBN-10D manufactured by Honda Iron Works) and further mixed for 1 minute to produce a clay-like cement composition.
Cement: Ordinary Portland cement (manufactured by Sumitomo Osaka Cement)
Silica: Silica Flower # 200 (made by Mizunami Silica)
Polypropylene fiber: PZL (Daiwabo)
Waste paper crushed material: PS (Nippon Paper Industries)
Cellulosic binder: Marporose ME-300000 (Matsumoto Yushi Seiyaku)

(Method for producing cement molding)
The cement composition obtained above was extruded using a vacuum extrusion molding machine (DE-50D manufactured by Honda Tekko Co., Ltd.) set to the following extrusion molding conditions, followed by primary curing (70 ° C., 12 hours) and autoclave Curing (170 ° C., 10 hours) was performed to produce a flat cement molded product.
[Extrusion conditions]
System temperature: 30 ° C
Degree of vacuum: -0.096 MPa or less Die size: 40 mm x 10 mm
The obtained cement molded product was cut so as to have a constant volume, and its specific gravity was measured using an upper plate electronic analysis balance AX200 and a specific gravity measurement kit SMK-301 manufactured by Shimadzu Corporation. The specific gravity of 1.45 was 1.45.

[Comparative Example 6]
A cement molded product was obtained in the same manner as in Example 11 except that hollow fine particles were not added in Example 11. The specific gravity of the obtained cement molded product was 1.70.

[Comparative Example 7]
Hollow fine particles prepared for dynamic durability evaluation of the thermally expandable microspheres obtained in Comparative Example 2 in Example 11 (average particle size 38 μm, true specific gravity 0.031 g / cc) 6.2 weight A cement molding was obtained in the same manner as in Example 11 except that the change was used for the part. The specific gravity of the obtained cement molded product was 1.63.
In the cement composition of Example 11, the specific gravity of the obtained molding is low, the durability against breakage due to the stress generated during mixing and extrusion molding of the hollow fine particles is excellent, the lightening effect is exhibited, and the excellent performance is achieved. Is clear.

Example 12
(Manufacture of ceramic composition and ceramic molding)
300 parts by weight of cordierite used as a ceramic material with inorganic components, 15 parts by weight of a cellulose-based binder, fine particles-attached hollow fine particles prepared for dynamic durability evaluation of the thermally expandable microspheres obtained in Example 3 (average A ceramic composition was prepared by kneading 26 parts by weight of a particle diameter of 30 μm and a true specific gravity of 0.13 g / cc) and 90 parts by weight of water.
The obtained ceramic composition was shaped by an extrusion molding method to form an unfired ceramic molded product.
When the specific gravity of the obtained ceramic molded product was measured in the same manner as in Example 11, the specific gravity of the ceramic molded product was 1.3.

[Comparative Example 8]
A ceramic molded product was obtained in the same manner as in Example 12 except that hollow fine particles were not added in Example 12. The specific gravity of the obtained ceramic molded product was 2.3.

[Comparative Example 9]
Hollow fine particles prepared in Example 12 for evaluation of the dynamic durability of the thermally expandable microspheres obtained in Comparative Example 2 were coated with fine particles (average particle size 38 μm, true specific gravity 0.13 g / cc) 26 weight A ceramic molded product was obtained in the same manner as in Example 12 except that the change was used for the part. The specific gravity of the obtained ceramic molded product was 2.2.
From the above results, it is clear that the ceramic composition containing the hollow fine particles of the present invention and an inorganic component such as a ceramic material has excellent performance.

1 Thermally expandable microspheres 2 Shell
3 Foaming agent (core)
4 Fine particle-attached hollow fine particle 5 Outer shell 6 Fine particle filler (adsorbed state)
7 Fine particle filler (indented and fixed state)
8 Hot Air Nozzle 9 Refrigerant Flow 10 Overheating Prevention Tube 11 Dispersion Nozzle 12 Colliding Plate 13 Gas Fluid Containing Thermally Expandable Microspheres 14 Gas Flow 15 Hot Air Flow 21 Hollow Fine Particles (Fine Particle Adhered Hollow Fine Particles)
22 Container 23 Piston 24 Hydraulic cylinder 25 Support base 26 Thermostatic chamber 27 Heater 28 In-vessel temperature sensor 29 Inert gas 30 Temperature sensor 31 Pressure sensor 32 Filter

Claims (11)

A thermally expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent contained therein and vaporized by heating;
The blowing agent is a hydrocarbon having 3 to 12 carbon atoms;
It contains a straight hydrocarbon (A) having 13 or more carbon atoms and an ester (B) represented by the following general formula (1), and the total of these two components (A + B) occupies the heat-expandable microspheres The proportion is 0.05 to 3% by weight,
The linear hydrocarbon (A) is a compound represented by the following general formula (2), and the ester (B) is a compound represented by the following general formula (3).
Thermally expandable microspheres.
R ¹ COOR ² (1)
(However, R ¹ and R ² are linear hydrocarbon groups, which may be the same or different.)
n-C _2X H _{4X + 2} (2)
(However, X is a number from 7 to 18.)
n-C _Y H _{2Y + 1} COO (n-C _Z H _{2Z + 1} ) (3)
(However, Y is a number from 6 to 18, and Z is a number from 6 to 18.)   The thermally expandable microsphere according to claim 1, wherein | X-Y |, | Y-Z |, and | Z-X | are all 3 or less.   The thermally expandable microsphere according to claim 1 or 2, wherein all of X, Y, and Z are numbers from 11 to 15. A thermally expandable microsphere composed of an outer shell made of a thermoplastic resin and a foaming agent contained therein and vaporized by heating;
The blowing agent is a hydrocarbon having 3 to 12 carbon atoms;
It contains a straight hydrocarbon (A) having 13 or more carbon atoms and an ester (B) represented by the following general formula (1), and the total of these two components (A + B) occupies the heat-expandable microspheres The proportion is 0.05 to 3% by weight,
The thermally expandable microsphere whose weight ratio (A / B) of the said linear hydrocarbon (A) and the said ester (B) is 35 / 65-80 / 20.
R ¹ COOR ² (1)
(However, R ¹ and R ² are linear hydrocarbon groups, which may be the same or different.)   The thermoplastic resin is composed of a copolymer obtained by polymerizing a monomer component containing a nitrile monomer, and the weight ratio of the nitrile monomer in the monomer component is 80% by weight. The thermally expandable microsphere according to any one of claims 1 to 4, which is as described above.   The thermally expandable microsphere according to any one of claims 1 to 5, wherein a fine particle filler adheres to the outer shell.   Hollow fine particles obtained by thermally expanding the thermally expandable microspheres according to any one of claims 1 to 6.   The composition containing the thermally expansible microsphere in any one of Claims 1-6, and / or the hollow microparticle of Claim 7, and a base material component.   The composition according to claim 8, wherein the base material component is at least one inorganic material selected from cements, cordierite, and silicon carbide.   The composition according to claim 8, which is an adhesive composition. A molded article formed by molding the composition according to claim 8.

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