JP2010100799A - Method for manufacturing single hollow polymer fine particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing single hollow polymer fine particles by which the single hollow polymer fine particles with extremely uniform outer and inner diameters are manufactured without necessitating classification, and to provide the single hollow polymer fine particles manufactured by the method. <P>SOLUTION: The method for manufacturing the single hollow polymer fine particles has: a step to mix a seed particle dispersion having seed particles including a noncrosslinkable polymer dispersed in a dispersion medium containing water, a polyaddition reactive oily material, and an oil soluble solvent together, and to prepare a dispersion of swollen particle liquid drops by making the seed particles absorb the polyaddition reactive oily material and the oil soluble solvent; and a step to mix the dispersion of the swollen particle liquid drops and a polyaddition reactive aqueous material which reacts with the polyaddition reactive oily material via polyaddition so as to polymerize the polyaddition reactive oily material and the polyaddition reactive aqueous material on an interface between the swollen particle liquid drops and the dispersion medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method for producing single-hole hollow polymer fine particles that can produce single-hole hollow polymer fine particles that do not require a classification operation and have extremely uniform outer diameter and inner diameter. Furthermore, the present invention relates to single-hole hollow polymer particles produced using the method for producing single-hole hollow polymer particles.

As a method for producing hollow polymer fine particles having a single hole, a monomer solution is prepared by uniformly dissolving a hydrophilic monomer, a crosslinkable monomer and an oil-soluble solvent together with a polymerization initiator, and the monomer solution is emulsified and dispersed in an aqueous phase. Then, there is a method of polymerizing. This manufacturing method is a method of forming single pores in fine particles by utilizing the phase separation effect between the polymer to be produced and the oil-soluble solvent.

However, the hollow polymer fine particles having a single hole obtained by this method have a particle size distribution that depends on the mechanical operation method of emulsification and dispersion, and the outer diameter (particle diameter), inner diameter (single hole diameter), and outer diameter There is a problem that it is difficult to control the ratio of the diameter to the inner diameter within a certain range.
For the purpose of aligning the outer diameter, it is difficult to obtain hollow polymer fine particles having a sufficiently uniform outer diameter distribution even if a classification operation is performed with a sieve or a mesh. Further, even if the outer diameter is made uniform, the inner diameter cannot be made uniform.
In addition, a method of classifying the obtained hollow polymer fine particles by a hydrodynamic method utilizing a specific gravity difference or the like is also known. However, fine particles having a large outer diameter and a large inner diameter (high hollowness) and fine particles having a small outer diameter and a small inner diameter (low hollowness) have the same mobility. Could not be classified.

On the other hand, a method for producing hollow polymer fine particles that are polymerized after the monomer component is absorbed in the seed particles has been studied. According to this method, it is considered that hollow polymer fine particles having a relatively uniform outer diameter can be produced.
For example, Patent Document 1 discloses that a polymerizable monomer component including a crosslinkable monomer, a hydrophilic monomer, and other monomers is contained in an aqueous dispersion medium in the presence of different polymer fine particles having a composition different from that of the copolymer of the polymerizable monomer component. A method for producing polymer particles having a single inner pore is described, which comprises the steps of dispersing the polymerizable monomer component in the different polymer fine particles and then polymerizing the polymerizable monomer component. In Patent Document 1, examples of the heterogeneous polymer include polystyrene or a copolymer of styrene and at least one selected from acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, and butadiene. Examples of the crosslinkable monomer include divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, and the like. Examples of the hydrophilic monomer include acrylic acid, methacrylic acid, methyl methacrylate, 2-hydroxyethyl methacrylate, vinyl pyridine, glycidyl acrylate, and glycidyl methacrylate. Examples of other monomers include styrene. However, with the method described in Patent Document 1, it has been difficult to obtain hollow polymer fine particles with sufficiently uniform outer diameter and inner diameter. Even in the examples of Patent Document 1, although generally single-hole hollow polymer fine particles are obtained, the outer diameter and inner diameter thereof are not uniform, and fine particles having a plurality of pores as well as single-pore structure fine particles are present. It was mixed.

Patent Document 2 discloses an ionic monomer (A-a), a non-ionic monomer (A-b) in which the solubility parameter does not change or increases with a change from monomer to polymer during polymerization, and the non-ionic monomer described above. In the presence of polymer fine particles (A) obtained by polymerizing a monomer containing a nonionic monomer (Ac) other than the monomer (Ab), the ionic monomer (Ba) is separated from the monomer during polymerization. A monomer component (B) containing a nonionic monomer (Bc) other than the nonionic monomer (Bb) and the nonionic monomer (Bb) whose solubility parameter decreases with the change to the polymer. A single inner pore having an average inner pore diameter of 0.25 to 0.8 times the average particle diameter of the fine particles by emulsion polymerization at a polymerization temperature satisfying certain conditions using a water-soluble polymerization initiator in an aqueous medium. Method for producing hollow polymer particles which have been described. In addition, in the production method described in Patent Document 2, a polymer obtained by polymerizing a nonionic monomer (Ab) component out of the combination of the polymer fine particles (A) and the monomer component (B). The absolute value of the difference between the solubility parameter [δ (A−b), p] and the solubility parameter [δ (B−b), m] of the monomer of the nonionic monomer (Bb) component is 1.0 or less It is said that it is the feature. However, with the method described in Patent Document 2, hollow polymer fine particles having a sufficiently uniform outer diameter and inner diameter could not be obtained. In addition, in the production method described in Patent Document 2, since a water-soluble polymerization initiator is used, the content of the polymerization initiator in the monomer oil droplets is small, so that not only the polymerization rate is lowered, but also in the aqueous phase. In addition, there was a problem that emulsion polymerization at the same time and fine particles without inner pores were also mixed.

In Patent Document 3, an oil droplet is obtained by press-fitting a homogeneous mixed solution A containing a hydrophilic monomer, a crosslinking monomer, another monomer, and an oily substance into a liquid B immiscible with A through a microporous membrane. A manufacturing method is shown in which particles having an oily substance as an inner core are obtained by polymerization after obtaining the above. However, the method of passing through the microporous membrane has a problem that, although the outer diameter distribution is uniform as compared with the conventional method using an emulsifying apparatus, it is necessary to perform operations such as classification.

Japanese Patent Publication No. 04-068324 Japanese Patent Laid-Open No. 04-279537 JP 2002-105104 A

An object of the present invention is to provide a method for producing single-hole hollow polymer fine particles that can produce single-hole hollow polymer fine particles having an extremely uniform outer diameter and inner diameter without requiring a classification operation. Furthermore, an object of the present invention is to provide single-hole hollow polymer particles produced using the method for producing single-hole hollow polymer particles.

The present invention mixes a seed particle dispersion in which seed particles containing a non-crosslinked polymer are dispersed in a dispersion medium containing water, a polyadditive oily substance, and an oil-soluble solvent. The step of absorbing the polyadditive oily substance and the oil-soluble solvent to prepare a dispersion of swollen particle droplets, and the polyaddition reaction with the dispersion of swollen particle droplets and the polyadditive oily substance A single-hole hollow having a step of polymerizing the polyadditive oily substance and the polyadditive aqueous substance at the interface between the swelling particle droplets and the dispersion medium by mixing the polyadditive aqueous substance. This is a method for producing polymer fine particles.
The present invention is described in detail below.

The method for producing single-hole hollow polymer fine particles of the present invention comprises a seed particle dispersion in which seed particles containing a non-crosslinked polymer are dispersed in a dispersion medium containing water, a polyadditive oily substance, and an oil-soluble solvent. And mixing the polyadditive oily substance and the oil-soluble solvent into the seed particles to prepare a dispersion of swollen particle droplets. In addition, the manufacturing method of the single hole hollow polymer microparticles | fine-particles of this invention may have the process of preparing the seed particle dispersion liquid which disperse | distributed the seed particle in the dispersion medium.

The seed particles contain a non-crosslinked polymer.
The non-crosslinkable monomer constituting the non-crosslinked polymer is not particularly limited. For example, styrene, methyl methacrylate, -n-butyl methacrylate, isobutyl methacrylate, methacrylic acid, methyl acrylate, n-butyl acrylate, Examples thereof include isobutyl acrylate and acrylic acid.

When polymerizing the non-crosslinkable monomer to form the seed particles, a small amount of a crosslinkable monomer may be used in combination. By using together a small amount of a crosslinkable monomer, the strength of the seed particles obtained is improved.
The crosslinkable monomer is not particularly limited, and examples thereof include divinylbenzene and ethylene glycol dimethacrylate.

When the crosslinkable monomer is blended, the preferable upper limit of the blending amount of the crosslinkable monomer in the total of the non-crosslinkable monomer and the crosslinkable monomer is 5% by weight. When the blending amount of the crosslinkable monomer exceeds 5% by weight, the absorbability of the polyaddition oily substance or the like to the seed particles to be obtained is lowered, and swollen particle droplets may not be formed. A more preferred upper limit of the amount of the crosslinkable monomer is 1% by weight.

The molecular weight of the seed particles is not particularly limited, but a preferable upper limit of the weight average molecular weight is 500,000. When the weight average molecular weight of the seed particles exceeds 500,000, the absorbability of polyaddition oily substances or the like to the obtained seed particles may be reduced, and swollen particle droplets may not be formed. A more preferable upper limit of the weight average molecular weight of the seed particles is 100,000. Although the minimum of the weight average molecular weight of the said seed particle is not specifically limited, When it is less than 1000, a particle | grain may not be formed substantially.

The volume average particle diameter of the seed particles is not particularly limited, but the preferable lower limit is 1/10 of the average outer diameter (average particle diameter) of the target single-hole hollow polymer fine particles, and the preferable upper limit is the target single-hole hollow polymer fine particles. 1 / 1.05 of the average outer diameter. If the volume average particle diameter of the seed particles is less than 1/10 of the average outer diameter of the desired single-hole hollow polymer fine particles, the limit of absorption performance is limited in order to obtain the desired outer diameter of the single-hole hollow polymer fine particles. It is necessary to absorb a large amount of the polyadditive oily substance and the like, which may cause absorption residue, and the outer diameter of the obtained single-hole hollow polymer fine particles may not be uniform. When the volume average particle diameter of the seed particles exceeds 1 / 1.05 of the average outer diameter of the desired single-hole hollow polymer fine particles, there is no room for absorption of a very small amount of polyadditive oily substance, etc., and high hollowness In some cases, single-hole hollow polymer microparticles having the above cannot be obtained. The volume average particle diameter of the seed particles is more preferably 1/8 or more, and more preferably 1 / 1.5 or less, of the average outer diameter of the target single-hole hollow polymer fine particles.

The shape of the seed particles is not particularly limited, but is preferably spherical. When the shape of the seed particles is not spherical, isotropic swelling may not occur when absorbing the polyadditive oily substance and the resulting single-hole hollow polymer fine particles may not be spherical.

The seed particle has a preferred upper limit of the Cv value of the particle diameter of 30%. When the Cv value of the particle diameter of the seed particles exceeds 30%, the particle diameter of the swollen seed particles may not be uniform, and the particle diameter of the obtained single-hole hollow polymer fine particles may not be uniform. A more preferable upper limit of the Cv value of the particle diameter of the seed particles is 20%.
The Cv value of the particle size of the seed particles can be calculated from the volume average particle size m measured with a particle size measuring device and the standard deviation σ according to the following formula (1).
Cv = σ / m × 100 (%) (1)
The average outer diameter of the single-hole hollow polymer fine particles was observed with a scanning electron microscope at a magnification at which about 100 particles could be observed in one field of view. It can be calculated by measuring the long diameter and obtaining the number average value of the longest diameter.

The method for preparing the seed particles is not particularly limited, and examples thereof include soap-free emulsion polymerization, emulsion polymerization, and dispersion polymerization.

The dispersion medium is not particularly limited as long as it contains water, and examples thereof include water or a mixed dispersion medium in which a water-soluble organic solvent such as methanol or ethanol is added to water.

The dispersion medium may contain a dispersant as necessary.
The dispersant is not particularly limited, and examples thereof include alkyl sulfate sulfonate, alkyl benzene sulfonate, alkyl sulfate triethanolamine, polyoxyethylene alkyl ether, and polyvinyl alcohol.

The blending amount of the seed particles in the seed particle dispersion is not particularly limited, and a preferable lower limit is 0.1% by weight and a preferable upper limit is 50% by weight. When the amount of the seed particles is less than 0.1% by weight, the production efficiency of the single-hole hollow polymer fine particles may be lowered. If the blended amount of the seed particles exceeds 50% by weight, the seed particles may aggregate. A more preferable lower limit of the blending amount of the seed particles is 0.5% by weight, and a more preferable upper limit is 30% by weight.

In the method for producing single-hole hollow polymer fine particles of the present invention, the seed particle dispersion, the polyadditive oily substance, and the oil-soluble solvent are mixed, and the polyadditive oily substance and the oil-soluble solvent are mixed with the seed particles. A dispersion of uniform swollen particle droplets is prepared by absorption.

In the present specification, the polyadditive oily substance means a compound having polyaddition properties and distributed to the organic phase side in a two-phase system of an aqueous phase and an organic phase.
The polyadditive oily substance is not particularly limited, and examples thereof include oily epoxy compounds, oily amine compounds, oily polythiol compounds, and oily diisocyanates.

The oily epoxy compound is not particularly limited, and examples thereof include bisphenol A type diglycidyl ether, bisphenol F type diglycidyl ether, resorcinol diglycidyl ether, and the like.
The oily amine compound is not particularly limited as long as it is an amine compound distributed to the organic phase side in a two-phase system of an aqueous phase and an organic phase, for example, an aliphatic amine having 5 or more carbon atoms or an alicyclic amine. Etc. Examples of the aliphatic amine include a primary amine, a secondary amine, or a tertiary amine in which an alkyl group having 5 or more carbon atoms is bonded to a nitrogen atom. Among these, a primary amine or a tertiary amine in which an alkyl group having 5 to 16 carbon atoms is bonded to a nitrogen atom is preferable, and a tertiary amine in which an alkyl group having 5 to 10 carbon atoms is bonded to a nitrogen atom is preferable. More preferred. As the alicyclic amine, an amine having a heterocyclic structure containing a nitrogen atom having 5 or more carbon atoms is preferable, and piperidine or a piperidine derivative is more preferable. For example, tri-n-octylamine, piperidine, tri-n-hexylamine, n-octylamine, metaxylene diamine, isophorone diamine, norbornene diamine, polyoxypropylene diamine and the like can be mentioned.

The oily polythiol compound is not particularly limited, and trimercaptopropionyloxyethyl isocyanurate, trimethylolpropane tri-3-methylmercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, dipentaerythritol hexa-3-mercapto Examples include propionate.

The oily diisocyanate is not particularly limited, and examples thereof include 4,4'-diphenylmethane diisocyanate, 4,4'-biphenyl diisocyanate tridenic diisocyanate, isophorone diisocyanate, and 1,3-xylylene diisocyanate.

In this specification, the oil-soluble solvent means a solvent having a logPow (octanol / water partition coefficient) of 0 or more. The logPow of the solvent is determined as follows.
After leaving the mixed liquid in which n-octanol and water are sufficiently mixed for 24 hours, a solvent is added to the mixed liquid and further mixed. Thereafter, the solvent concentration (Co) contained in the octanol phase and the solvent concentration (Cw) contained in the aqueous phase were measured by gas chromatography. Using the obtained Co and Cw, the following formula (2) was obtained. logPow can be calculated.
logPow = log (Co / Cw) (2)
Co: solvent concentration in octanol phase Cw: solvent concentration in water phase

The oil-soluble solvent is not particularly limited, and examples thereof include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as heptane and isooctane, cyclic hydrocarbons such as cyclohexane, ketones such as methyl isobutyl ketone, And esters such as ethyl acetate. When these oil-soluble solvents are used, single-hole hollow polymer fine particles having cavities are formed by forming a shell of single-hole hollow polymer fine particles as described later, and then vacuum drying to volatilize the oil-soluble solvent. You may manufacture and the single-hole hollow polymer microparticle which includes the said oil-soluble solvent without volatilizing the said oil-soluble solvent may be manufactured.
These oil-soluble solvents may be used alone or in combination of two or more.

Moreover, you may use a hardening | curing agent or a hardening accelerator as said oil-soluble solvent.
The curing agent is not particularly limited. For example, imidazole compounds such as 2-ethyl-4-methylimidazole (2E4MZ) and 2-methylimidazole (2MZ), polyamine compounds such as polyethylene polyamine and metaxylenediamine, and trialkyls. Examples of the acid anhydride include tetrahydrophthalic anhydride and trimellitic anhydride. The curing accelerator is not particularly limited, and examples thereof include chlorine-substituted carboxylic acid compounds such as monochloroacetic acid and dichloroacetic acid, chlorine-substituted phenolic compounds such as p-chlorophenol and o-chlorophenol, and nitro such as p-nitrophenol. Examples include substituted phenol compounds and mercaptan compounds such as thiophenol and 2-mercaptoethanol. When these oil-soluble solvents are used, single-hole hollow polymer fine particles enclosing the oil-soluble solvent can be produced.
The oil-soluble solvent and the polyaddition oil-based substance may be the same.
These oil-soluble solvents may be used alone or in combination of two or more.

The blending amount of the oil-soluble solvent may be appropriately adjusted according to the outer diameter and inner diameter of the target single-hole hollow polymer fine particles, but the preferred lower limit with respect to 100 parts by weight of the polyadditive oily substance is 10 parts by weight, and the preferred upper limit is 10,000 parts by weight. When the blending amount of the oil-soluble solvent is less than 10 parts by weight, inner holes may not be formed. When the blending amount of the oil-soluble solvent exceeds 10,000 parts by weight, the strength of the obtained single-hole hollow polymer fine particles may be significantly reduced. A more preferred lower limit of the amount of the oil-soluble solvent is 20 parts by weight, and a more preferred upper limit is 1000 parts by weight.

When mixing the seed particle dispersion, the polyadditive oily substance, and the oil-soluble solvent, the polyadditive oily substance and the oil-soluble solvent are added directly to the seed particle dispersion and mixed. However, it is preferable to add the dispersion liquid containing water once to prepare an emulsion, and add the emulsion to the seed particle dispersion and mix. Once added as an emulsified liquid, the polyadditive oily substance and the like can be more uniformly absorbed by the seed particles.
The polyadditive oily substance and the oil-soluble solvent may be prepared by preparing an emulsion of these mixtures and mixing them in addition to the seed particle dispersion. Alternatively, each emulsion may be prepared separately. You may mix in addition to a seed particle dispersion. The seed particle dispersion may be added to the emulsion and mixed.

The dispersion medium of the emulsified liquid such as the polyadditive oily substance is not particularly limited, and may be the same dispersion medium as that used in the seed particle dispersion liquid or a different dispersion medium.
The dispersion medium of the emulsion such as the polyadditive oily substance preferably contains an emulsifier. The emulsifier is not particularly limited, and examples thereof include alkyl sulfate sulfonate, alkyl benzene sulfonate, alkyl sulfate triethanolamine, polyoxyethylene alkyl ether, and polyvinyl alcohol.

When mixing the emulsion such as the polyadditive oily substance and the seed particle dispersion, the whole amount of the emulsion may be added in a lump, or may be divided and added. Good. When adding by dividing | segmenting, you may add by dripping.

The addition amount of the oil component of the polyaddition oily substance and the oil-soluble solvent is not particularly limited, but a preferable lower limit with respect to 100 parts by weight of the seed particles is 15 parts by weight, and a preferable upper limit is 100,000 parts by weight. When the amount of the oil component added is less than 15 parts by weight, the inner hole may not be formed. When the added amount of the oil component exceeds 100,000 parts by weight, an oil component that cannot be absorbed by the seed particles is generated, which may cause mixing of solid fine particles and the like. The more preferable lower limit of the addition amount of the oil component is 230 parts by weight, and the more preferable upper limit is 50,000 parts by weight.

When the seed particle dispersion, the polyadditive oily substance, and the oil-soluble solvent are mixed, the polyadditive oily substance and the oil-soluble solvent are absorbed by the seed particles, and a uniform swollen particle liquid is obtained. Drops are formed.

In the method for producing single-hole hollow polymer fine particles of the present invention, a step of mixing the obtained dispersion of swollen particle droplets and a polyaddition aqueous substance that undergoes a polyaddition reaction with the polyaddition oily substance is performed.

The polyaddition aqueous substance is not particularly limited as long as it is a substance that undergoes a polyaddition reaction with the polyaddition oily substance and is distributed to the aqueous phase side in a two-phase system of an aqueous phase and an organic phase.
When the polyadditive oily substance is an oily epoxy compound, examples of the polyadditive aqueous substance include an aqueous amine compound.
The aqueous amine compound is not particularly limited, and examples thereof include aliphatic amines such as polymethylene diamine, polyether diamine, aminoethylpiperazine, and isophorone diamine, aromatic amines such as xylylenediamine, diaminodiphenyl ether, and toluene diamine, and anhydrous amines. Examples include acid anhydrides such as phthalic acid derivatives, maleic anhydride-vinyl ether copolymers, tertiary amines such as polyphenols, polythiols, and benzyldimethylamine, and imidazoles such as 2-ethyl-4-methylimidazole. .

When the polyadditive oily substance is an oily amine compound, examples of the polyadditive aqueous substance include an aqueous epoxy compound.
The aqueous epoxy compound is not particularly limited, and examples thereof include polyglycerol polyglycidyl ether.

When the polyaddition oily substance is an oily diisocyanate, examples of the polyaddition aqueous substance include an aqueous diol compound and an aqueous amine compound.
The aqueous diol compound is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, and tetramethylene glycol.

The addition amount of the polyaddition aqueous substance is not particularly limited, but the active site of the polyaddition aqueous substance is within the range of 1 to 10,000 molar equivalents relative to 100 mole equivalent of the active site of the polyaddition oily substance. It is preferable that When the addition amount of the polyaddition aqueous substance is less than 1 molar equivalent, the polyaddition oily substance and the polyaddition aqueous substance hardly react with each other, so that an inner hole may not be formed. When the addition amount of the polyaddition aqueous substance exceeds 10,000 molar equivalents, the polyaddition aqueous substance that does not react with the polyaddition oily substance remains, and the particles may aggregate. The minimum with more preferable addition amount of the said polyaddition aqueous substance is 10 molar equivalent, and a more preferable upper limit is 1000 molar equivalent.

The polyadditive oily substance and the polyadditive aqueous substance are mixed at the interface between the swollen particle drop and the dispersion medium by mixing the dispersion of the swollen particle droplets and the polyadditive aqueous substance. A core-shell particle dispersion having a shell formed of a polymer obtained by polymerizing and an oil-soluble solvent as a core is obtained.
In the method for producing single-hole hollow polymer fine particles of the present invention, the obtained core-shell particles are repeatedly washed with pure water, vacuum-dried, and the oil-soluble solvent is volatilized, whereby a single-hole hollow having a cavity is obtained. Polymer fine particles may be produced, or single-hole hollow polymer fine particles enclosing the oil-soluble solvent may be produced without volatilizing the oil-soluble solvent.

According to the method for producing single-hole hollow polymer particles of the present invention, single-hole hollow polymer particles having an extremely uniform outer diameter and inner diameter can be produced. Since the outer diameter and inner diameter are extremely uniform, no special classification operation such as sieving, air classification, specific gravity differential class or the like is required. Since the yield is high and the process is short, the single-hole hollow polymer fine particles can be supplied cheaply and quickly.
The single-hole hollow polymer particles produced using the method for producing single-hole hollow polymer particles of the present invention are also one aspect of the present invention.

The single-hole hollow polymer fine particles of the present invention may have cavities and may contain the oil-soluble solvent.
When the single-hole hollow polymer fine particles of the present invention have cavities, the outer diameter and inner diameter are extremely uniform, so that the specific surface area can be improved with a very small amount of addition, and light diffusibility, light weight, heat insulation Further, cushioning, selective absorption, reflection, and transmission of ultraviolet rays, visible light, infrared rays, and the like can be controlled.

When the single-hole hollow polymer fine particles of the present invention include a curing agent or a curing accelerator as the oil-soluble solvent, for example, a microcapsule that includes a curing agent or a curing accelerator for producing a cured product such as an epoxy resin. Can be used as In other words, the single-hole hollow polymer fine particles of the present invention containing a curing agent or a curing accelerator are contained in the curable composition, and the curing reaction is initiated by breaking the shell with mechanical pressure or heat as necessary. To produce a cured product. Since the outer diameter and inner diameter of the single-hole hollow polymer fine particles of the present invention are extremely uniform, the curable composition containing the single-hole hollow polymer fine particles of the present invention begins to harden during storage in a thin portion of the shell. In addition, the curing agent or the curing accelerator does not sufficiently ooze out during the curing in the thick part of the shell, and the reactivity is not lowered. As a result, the storage stability is high and the curing is uniform.

The average outer diameter (average particle diameter) of the single-hole hollow polymer fine particles of the present invention is not particularly limited, but a preferable lower limit is 0.1 μm and a preferable upper limit is 100 μm. If the average outer diameter is less than 0.1 μm, a sufficiently large single hole may not be obtained, or the amount of the oil-soluble solvent contained may be reduced. When the average outer diameter exceeds 100 μm, the absorption of the oil-soluble solvent into the seed particles is delayed, and thus productivity may be reduced. The more preferable lower limit of the average outer diameter of the single-hole hollow polymer fine particles of the present invention is 0.5 μm, and the more preferable upper limit is 20 μm.

In the single-hole hollow polymer fine particles of the present invention, the preferable upper limit of the Cv value of the outer diameter (particle diameter) is 10%. When the Cv value of the outer diameter exceeds 10%, for example, when the single-hole hollow polymer fine particles of the present invention are used as a microcapsule encapsulating a curing agent or a curing accelerator for producing a cured product such as an epoxy resin The cured product may not be homogeneously cured. A more preferable upper limit of the Cv value of the outer diameter is 7%.
The Cv value of the outer diameter of the single-hole hollow polymer fine particles of the present invention can be calculated in the same manner as the Cv value of the particle diameter of the seed particles.

The average inner diameter of the single-hole hollow polymer fine particles of the present invention is not particularly limited, but a preferable lower limit is 5% of the average outer diameter, and a preferable upper limit is 99.9% of the average outer diameter. If the average inner diameter is less than 5% of the average outer diameter, a sufficiently large single hole may not be obtained, or the amount of the oil-soluble solvent contained may be reduced. When the average inner diameter exceeds 99.9% of the average outer diameter, the shell becomes thin, so that the oil-soluble solvent contained may leak out. The more preferable lower limit of the average inner diameter of the single-hole hollow polymer fine particles of the present invention is 10% of the average outer diameter, and the more preferable upper limit is 99% of the average outer diameter.

In the single-hole hollow polymer fine particles of the present invention, the preferable upper limit of the Cv value of the inner diameter is 10%. When the Cv value of the inner diameter exceeds 10%, for example, when the single-hole hollow polymer fine particles of the present invention are used as microcapsules enclosing a curing agent or a curing accelerator for producing a cured product such as an epoxy resin, Curing of the cured product may not be uniform. A more preferable upper limit of the Cv value of the inner diameter is 7%.
In addition, the Cv value of the inner diameter of the single-hole hollow polymer fine particle of the present invention can be calculated in the same manner as the Cv value of the particle diameter of the seed particle.

According to the present invention, it is possible to provide a method for producing single-hole hollow polymer fine particles that do not require a classification operation and can produce single-hole hollow polymer fine particles having an extremely uniform outer diameter and inner diameter. Furthermore, according to this invention, the single-hole hollow polymer microparticle manufactured using the manufacturing method of this single-hole hollow polymer microparticle can be provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
100 parts by weight of styrene, 3 parts by weight of potassium persulfate, 25 parts by weight of n-octyl mercaptan, and 2500 parts by weight of water were mixed and reacted at 70 ° C. for 24 hours with stirring, and a volume average particle size of 0.5 μm, Cv value A seed particle dispersion was prepared in which 15% and spherical non-crosslinked polystyrene particles were dispersed in water at a concentration of 1.5% by weight.

A mixed solution in which 10 parts by weight of bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) as a polyadditive oily substance and 90 parts by weight of heptane as an oil-soluble solvent are uniformly dissolved, triethanolamine lauryl sulfate as an emulsifier 2 parts by weight and water were added and mixed to prepare an emulsion.

To the obtained seed particle dispersion, an emulsified liquid is added and mixed so as to become an oily component 200 times the weight of polystyrene particles, and stirred for 24 hours to absorb the polyaddition oily substance and oil-soluble solvent. A dispersion of droplets of swollen particles was obtained. The oil component includes a polyaddition oil material and an oil-soluble solvent as constituent components.
While stirring the obtained dispersion of swollen particle droplets, 1 part by weight of 1,3-bisaminomethylcyclohexane (“1,3-BAC” manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a polyadditive aqueous substance was dropped, By reacting at 80 ° C. for 5 hours, a core-shell particle dispersion having a core formed of heptane and a shell formed of polyepoxy was obtained.
The obtained core-shell particles were repeatedly washed with pure water, vacuum dried to volatilize heptane, and polymer fine particles were obtained.

(Example 2)
1 part by weight of polyoxypropylene triamine ("D-230" manufactured by BASF) is used as the polyaddition oily substance, and an aqueous epoxy ("Denacol EX-1310" manufactured by Nagase ChemteX) is used as the polyaddition aqueous substance 10 Polymer fine particles were obtained in the same manner as in Example 1 except that parts by weight were used.

(Example 3)
Polymer fine particles were obtained in the same manner as in Example 1 except that 10 parts by weight of hexamethylene diisocyanate type resin (“Duranate TSA-100” manufactured by Asahi Kasei Chemicals Corporation) was used as the polyadditive oily substance.

Example 4
100 parts by weight of styrene, 5 parts by weight of potassium persulfate, 25 parts by weight of n-octyl mercaptan, and 2500 parts by weight of water were mixed and reacted at 70 ° C. for 24 hours with stirring, and a volume average particle size of 0.2 μm, Cv value. A seed particle dispersion was prepared in which 15% and spherical non-crosslinked polystyrene particles were dispersed in water at a concentration of 1.5% by weight.

A mixed solution in which 10 parts by weight of bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) as a polyadditive oily substance and 90 parts by weight of heptane as an oil-soluble solvent are uniformly dissolved, triethanolamine lauryl sulfate as an emulsifier 2 parts by weight and water were added and mixed to prepare an emulsion.

Polymer fine particles were obtained in the same manner as in Example 1 except that an emulsion was added to the obtained seed particle dispersion so that the oil component was 20 times the weight of polystyrene particles.

(Example 5)
100 parts by weight of styrene, 0.5 part by weight of potassium persulfate, 25 parts by weight of n-octyl mercaptan, and 2500 parts by weight of water were mixed and reacted at 70 ° C. for 24 hours with stirring to obtain a volume average particle size of 2.0 μm, A seed particle dispersion having a Cv value of 15% and spherical non-crosslinked polystyrene particles dispersed in water at a concentration of 1.5% by weight was prepared.

A mixed solution in which 10 parts by weight of bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) as a polyadditive oily substance and 90 parts by weight of heptane as an oil-soluble solvent are uniformly dissolved, triethanolamine lauryl sulfate as an emulsifier 2 parts by weight and water were added and mixed to prepare an emulsion.

Polymer fine particles were obtained in the same manner as in Example 1 except that an emulsion was added to the obtained seed particle dispersion so that the oil component was 125 times the weight of polystyrene particles.

(Example 6)
100 parts by weight of styrene, 0.5 part by weight of potassium persulfate, 0.1 part by weight of sodium chloride, 25 parts by weight of n-octyl mercaptan, 2500 parts by weight of water are mixed and reacted at 70 ° C. for 24 hours with stirring. A seed particle dispersion was prepared in which a volume average particle diameter of 5.0 μm, a Cv value of 15%, and spherical non-crosslinked polystyrene particles were dispersed in water at a concentration of 1.5% by weight.

A mixed solution in which 10 parts by weight of bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) as a polyadditive oily substance and 90 parts by weight of heptane as an oil-soluble solvent are uniformly dissolved, triethanolamine lauryl sulfate as an emulsifier 2 parts by weight and water were added and mixed to prepare an emulsion.

Polymer fine particles were obtained in the same manner as in Example 1 except that an emulsion was added to the obtained seed particle dispersion so that the oil component was 125 times the weight of polystyrene particles.

(Comparative Example 1)
10 parts by weight of bisphenol A type epoxy resin (“Epicoat 828” manufactured by Japan Epoxy Resin Co., Ltd.) as a polyadditive oily substance and 90 parts by weight of heptane as an oil-soluble solvent are uniformly dissolved, and contain an emulsifier and water through a porous membrane. An emulsified dispersion was prepared by dispersing in a continuous layer.
While stirring the obtained emulsified dispersion, 1 part by weight of 1,3-bisaminomethylcyclohexane (“1,3-BAC” manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a polyadditive aqueous substance was added dropwise, and 5% at 80 ° C. By reacting for a time, a core-shell particle dispersion having a core formed of heptane and a shell formed of polyepoxy was obtained.
The obtained core-shell particles were repeatedly washed with pure water, vacuum dried to volatilize heptane, and polymer fine particles were obtained.

(Evaluation)
The polymer fine particles obtained in Examples 1 to 6 and Comparative Example 1 were evaluated by the following methods. The results are shown in Table 1.

(1) Measurement of outer diameter The obtained polymer fine particles are observed with a scanning electron microscope at a magnification at which about 100 particles can be observed in one field of view, and the arbitrarily selected 50 fine particles are measured with a caliper to determine the longest diameter. The number average value and the coefficient of variation of this value were obtained, and these were used as the average outer diameter and outer diameter Cv value.

(2) Measurement of inner diameter and evaluation of single porosity After the obtained polymer fine particles were embedded in an epoxy resin, the resin was cured, and a cross section was cut out with a microtome. The obtained slice was observed with a scanning electron microscope at a magnification at which about 100 cross sections could be observed in one field of view.
Regarding the single porosity, the cross section of 50 fine particles arbitrarily selected was observed, and when the number of particles having a single pore was 49 or more, “◎” was 45 to 48. The case was evaluated as “◯”, the case of 40 to 44 as “Δ”, and the case of 39 or less as “×”.
In addition, for the cross section of 50 arbitrarily selected fine particles, the longest diameter of a single hole was measured using a caliper, the number average value and the coefficient of variation of this value were obtained, and these were calculated as the average inner diameter and inner diameter Cv value. did. The average inner diameter and the inner diameter Cv value were calculated for particles having a single hole.

(Example 7)
100 parts by weight of styrene, 3 parts by weight of potassium persulfate, 25 parts by weight of n-octyl mercaptan, and 2500 parts by weight of water were mixed and reacted at 70 ° C. for 24 hours with stirring, volume average particle diameter 0.5 μm, Cv value A seed particle dispersion was prepared in which 15% and spherical non-crosslinked polystyrene particles were dispersed in water at a concentration of 1.5% by weight.

In a mixed solution in which 100 parts by weight of 2-ethyl-4-methylimidazole (2E4MZ) and 100 parts by weight of toluene as an oil-soluble solvent were uniformly dissolved as a polyaddition oily substance and oil-soluble solvent, lauryl sulfate triethanolamine 2 was added as an emulsifier. Part by weight and water were added and mixed to prepare an emulsion.

To the obtained seed particle dispersion, an emulsion is added so that the oil component is 200 times the weight of the polystyrene particles, and the mixture is stirred for 24 hours to absorb the polyaddition oily substance and the oil-soluble solvent, and the seed particle swelling particles. A droplet dispersion was obtained.
While stirring the obtained dispersion of swollen particle droplets, 1 part by weight of an aqueous epoxy (“Denacol EX-1310” manufactured by Nagase ChemteX Corp.) is added dropwise as a polyadditive aqueous substance and reacted at 80 ° C. for 10 hours. As a result, a core-shell particle dispersion in which the core was formed of toluene / 2-ethyl-4-methylimidazole (2E4MZ) and the shell was formed of an epoxy resin was obtained.
The obtained core-shell particles were repeatedly washed with pure water, vacuum-dried, and toluene was volatilized to obtain polymer fine particles.

(Example 8)
Polymer fine particles were obtained in the same manner as in Example 7, except that 100 parts by weight of 2-methylimidazole (2MZ) was used as the polyaddition oily substance and the oil-soluble solvent.

Example 9
100 parts by weight of styrene, 5 parts by weight of potassium persulfate, 25 parts by weight of n-octyl mercaptan, and 2500 parts by weight of water were mixed and reacted at 70 ° C. for 24 hours with stirring, and a volume average particle size of 0.2 μm, Cv value. A seed particle dispersion was prepared in which 15% and spherical non-crosslinked polystyrene particles were dispersed in water at a concentration of 1.5% by weight.

In a mixed solution in which 100 parts by weight of 2-ethyl-4-methylimidazole (2E4MZ) and 100 parts by weight of toluene as an oil-soluble solvent were uniformly dissolved as a polyaddition oily substance and oil-soluble solvent, lauryl sulfate triethanolamine 2 was added as an emulsifier. Part by weight and water were added and mixed to prepare an emulsion.

Polymer fine particles were obtained in the same manner as in Example 7 except that an emulsion was added to the obtained seed particle dispersion so that the oil component was 20 times the weight of polystyrene particles.

(Example 10)
100 parts by weight of styrene, 0.5 parts by weight of potassium persulfate, 25 parts by weight of n-octyl mercaptan, and 2500 parts by weight of water were mixed and reacted at 70 ° C. for 24 hours with stirring to obtain a volume average particle size of 2.0 μm, A seed particle dispersion having a Cv value of 15% and spherical non-crosslinked polystyrene particles dispersed in water at a concentration of 1.5% by weight was prepared.

In a mixed solution in which 100 parts by weight of 2-ethyl-4-methylimidazole (2E4MZ) and 100 parts by weight of toluene as an oil-soluble solvent were uniformly dissolved as a polyaddition oily substance and oil-soluble solvent, lauryl sulfate triethanolamine 2 was added as an emulsifier. Part by weight and water were added and mixed to prepare an emulsion.

Polymer fine particles were obtained in the same manner as in Example 7 except that an emulsion was added to the obtained seed particle dispersion so that the oil component was 125 times the weight of polystyrene particles.

(Example 11)
100 parts by weight of styrene, 0.5 part by weight of potassium persulfate, 0.1 part by weight of sodium chloride, 25 parts by weight of n-octyl mercaptan, 2500 parts by weight of water are mixed and reacted at 70 ° C. for 24 hours with stirring. A seed particle dispersion was prepared in which a volume average particle diameter of 5.0 μm, a Cv value of 15%, and spherical non-crosslinked polystyrene particles were dispersed in water at a concentration of 1.5% by weight.

In a mixed solution in which 100 parts by weight of 2-ethyl-4-methylimidazole (2E4MZ) and 100 parts by weight of toluene as an oil-soluble solvent were uniformly dissolved as a polyaddition oily substance and oil-soluble solvent, lauryl sulfate triethanolamine 2 was added as an emulsifier. Part by weight and water were added and mixed to prepare an emulsion.

Polymer fine particles were obtained in the same manner as in Example 7 except that an emulsion was added to the obtained seed particle dispersion so that the oil component was 125 times the weight of polystyrene particles.

(Comparative Example 2)
To 400 parts by weight of an isopropyl alcohol solution containing 2 parts by weight of methacrylic acid, 8 parts by weight of acrylonitrile and 0.1 part by weight of 2,2-azobis (4-methoxy-2,4-dimethylvaleronitrile), an average particle size of 5 μm is previously provided. 90 parts by weight of finely pulverized 1-cyanoethyl-2-phenylimidazole was dispersed. By reacting this dispersion at 50 ° C. for 3 hours in a nitrogen atmosphere, a core-shell particle dispersion in which the core is formed of 1-cyanoethyl-2-phenylimidazole and the shell is formed of a methacrylic acid / acrylonitrile copolymer is obtained. Obtained. Thereafter, the obtained dispersion was filtered to obtain polymer fine particles.

(Comparative Example 3)
To a 1000 mL three-necked round bottom flask equipped with a thermometer, a reflux condenser and a Teflon (registered trademark) half-moon stirrer, 28.0 g of 2-methylimidazole (2MZ) and an acrylic polymer (“RESEDA” manufactured by Toagosei Co., Ltd.) GP-300 ")) was charged to 4.99 g, then 593.95 g of methyl isobutyl ketone (MIBK) was added and the temperature was raised to 70 ° C to completely dissolve. Next, 143.74 g of a 50 wt% MIBK solution of bisphenol A type epoxy resin (Japan Epoxy Resin “Epicoat 828”) was added and mixed, and the mixture was reacted at 70 ° C. for 10 hours while stirring at a speed of 300 rpm. By causing the reaction rate to reach almost 100%, a core-shell particle dispersion in which the core was formed of 2-methylimidazole (2MZ) and the shell was formed of an acrylic polymer was obtained. Thereafter, the obtained dispersion was filtered to obtain polymer fine particles.

(Comparative Example 4)
In a mixed solution in which 100 parts by weight of 2-ethyl-4-methylimidazole (2E4MZ) and 100 parts by weight of toluene as an oil-soluble solvent were uniformly dissolved as a polyaddition oily substance and oil-soluble solvent, lauryl sulfate triethanolamine 2 was added as an emulsifier. Part by weight and water were added and mixed to prepare an emulsion.

Polymer fine particles were obtained in the same manner as in Example 7, except that the obtained emulsion was added to water (no seed particles were used).

(Evaluation)
The polymer fine particles obtained in Examples 7 to 11 and Comparative Examples 2 to 4 were evaluated by the following methods. The results are shown in Table 2.

(1) Measurement of outer diameter The obtained polymer fine particles are observed with a scanning electron microscope at a magnification at which about 100 particles can be observed in one field of view, and the arbitrarily selected 50 fine particles are measured with a caliper to determine the longest diameter. The number average value and the coefficient of variation of this value were obtained, and these were used as the average outer diameter and outer diameter Cv value.

(2) Measurement of inner diameter and evaluation of single porosity After the obtained polymer fine particles were embedded in an epoxy resin, the resin was cured, and a cross section was cut out with a microtome. The obtained slice was observed with a scanning electron microscope at a magnification at which about 100 cross sections could be observed in one field of view.
Regarding the single porosity, the cross section of 50 fine particles arbitrarily selected was observed, and when the number of particles having a single pore was 49 or more, “◎” was 45 to 48. The case was evaluated as “◯”, the case of 40 to 44 as “Δ”, and the case of 39 or less as “×”.
In addition, for the cross section of 50 arbitrarily selected fine particles, the longest diameter of a single hole was measured using a caliper, the number average value and the coefficient of variation of this value were obtained, and these were calculated as the average inner diameter and inner diameter Cv value. did. The average inner diameter and the inner diameter Cv value were calculated for particles having a single hole.

(3) Evaluation of storage stability A mixture of 10 parts by weight of the obtained polymer fine particles and 100 parts by weight of an epoxy resin (“JER828” manufactured by Japan Epoxy Resin Co., Ltd.) was left at 40 ° C. for 7 days. After standing, the case where the mixture was not in a gel state was evaluated as “◯”, and the case where the mixture was in a gel state was evaluated as “X”.

According to the present invention, it is possible to provide a method for producing single-hole hollow polymer fine particles that can produce single-hole hollow polymer fine particles that do not require a classification operation and have extremely uniform outer diameter and inner diameter. Furthermore, according to this invention, the single-hole hollow polymer microparticle manufactured using the manufacturing method of this single-hole hollow polymer microparticle can be provided.

Claims (7)

A seed particle dispersion in which seed particles containing a non-crosslinked polymer are dispersed in a dispersion medium containing water, a polyadditive oily substance, and an oil-soluble solvent are mixed, and the polyadditive property is added to the seed particles. A step of absorbing an oily substance and the oil-soluble solvent to prepare a dispersion of swollen particle droplets;
The polyaddition at the interface between the swollen particle droplets and the dispersion medium is performed by mixing the dispersion of the swollen particle droplets with a polyaddition aqueous substance that undergoes a polyaddition reaction with the polyaddition oily substance. A method for producing single-hole hollow polymer fine particles comprising a step of polymerizing a hydrophilic oily substance and the polyadditive aqueous substance. The single-hole hollow polymer according to claim 1, wherein an emulsion obtained by dispersing a polyadditive oily substance and an oil-soluble solvent in a dispersion medium containing water and a seed particle dispersion are mixed. A method for producing fine particles. The method for producing single-hole hollow polymer fine particles according to claim 1 or 2, wherein the seed particles have a Cv value of particle diameter of 30% or less. The method for producing single-hole hollow polymer particles according to claim 1, 2 or 3, wherein the oil-soluble solvent is a curing agent or a curing accelerator. A single-hole hollow polymer particle produced using the method for producing a single-hole hollow polymer particle according to claim 1, 2, 3, or 4. 6. The single-hole hollow polymer fine particle according to claim 5, wherein the average outer diameter is 0.1 to 100 [mu] m, and the Cv value of the outer diameter is 10% or less. The single-hole hollow polymer fine particle according to claim 5 or 6, wherein the Cv value of the inner diameter is 10% or less.