JP5214923B2 - Method for producing vinyl resin particles - Google Patents

Description

  The present invention relates to a method for producing vinyl resin particles. More specifically, the present invention efficiently produces vinyl resin particles having an average particle diameter of 1 to 200 μm having wrinkles on the surface, which are useful in the electric, electronic, medical, chemical, cosmetic and other industrial fields. It is about how to do.

In recent years, resin fine particles having an average particle size of several μm to several tens of μm have been used for various purposes in fields such as paints, cosmetics, and light diffusing agents.
However, since the resin fine particles that are generally used have a true spherical shape, it is required to have high functionality such as providing matte and concealing properties for paints, and providing scattering and adhesion properties for cosmetics. In such a case, the above function could not be sufficiently exhibited, and there was room for improvement.
For example, in order to further enhance the function of spherical resin fine particles, Patent Document 1 discloses a method for producing disk-shaped resin fine particles, Patent Document 2 discloses plate-shaped resin fine particles, and Patent Document 3 discloses a method for producing hollow non-spherical resin fine particles. Yes.

JP-A-63-117040 JP-A-3-234734 Japanese Patent Laid-Open No. 7-157672

  Under such circumstances, the present invention effectively and efficiently produces vinyl resin particles having wrinkles on the surface and useful in the electrical, electronic, medical, chemical, cosmetic and other industrial fields. It is an object to provide a manufacturing method.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained an aqueous dispersion in which droplets of vinyl monomers containing a predetermined proportion of fatty acid esters that function as plasticizers are dispersed. A liquid is prepared, and the vinyl monomer in the aqueous dispersion is polymerized by using a specific operation, so that a vinyl surface having wrinkles on the target surface and an average particle diameter of 1 to 200 μm is prepared. It has been found that resin particles can be obtained. The present invention has been completed based on such findings.

That is, the present invention
[1] (a) An aqueous dispersion preparation step of preparing an aqueous dispersion by dispersing droplets of vinyl monomer A in an aqueous medium, and (b) a vinyl-based monomer in the aqueous dispersion. A method for producing vinyl-based resin particles having an average particle diameter of 1 to 200 μm having wrinkles on the surface, including a polymerization step of polymerizing the body A,
(1) The droplet of the vinyl monomer A in the step (a) includes a plasticizer composed of fatty acid esters, and the amount of the plasticizer added is 100 parts by weight of the vinyl monomer A. 0.1 to 3 parts by weight,
(2) In the step (b), the solubility parameter (SP value) is 13.0 to 15.0 (MPa) ^{1/2 when} the polymerization conversion rate of the vinyl monomer A is 50 to 80%. Adding a hydrocarbon compound to the polymerization reaction system; and (3) in the step (b), following the operation of (2) above, adding the vinyl monomer B and the crosslinking agent to the polymerization reaction system; and The addition amount of the vinyl monomer B is 1 to 10 parts by weight with respect to 100 parts by weight of the vinyl monomer A,
A method for producing vinyl-based resin particles,
[2] The method for producing vinyl resin particles according to the above [1], wherein the addition amount of the hydrocarbon compound is 10 to 40 parts by weight with respect to 100 parts by weight of the vinyl monomer A.
[3] The method for producing vinyl resin particles according to the above [1] or [2], wherein the hydrocarbon compound has a boiling point of less than 60 ° C.
[4] The above-mentioned [1], wherein the vinyl monomer A and the monomer include (meth) acrylic acid ester as a main component, and the vinyl monomer B includes a vinyl aromatic compound as a main component. -The manufacturing method of the vinyl resin particle in any one of [3],
[5] The method for producing vinyl resin particles according to any one of the above [1] to [4], wherein the vinyl monomer A contains methyl (meth) acrylate and α-methylstyrene,
[6] The method for producing vinyl resin particles according to any one of the above [1] to [5], wherein the crosslinking agent added in the step (b) is divinylbenzene, and in the step [7] (b). The method for producing vinyl resin particles according to any one of the above [1] to [6], wherein the addition amount of the crosslinking agent is 0.5 to 20 parts by weight with respect to 100 parts by weight of the vinyl monomer A,
Is to provide.

According to the production method of the present invention, in preparation of an aqueous dispersion, a vinyl monomer in a state where a specific amount of a plasticizer comprising a fatty acid ester is added is dispersed in an aqueous medium, and a solubility parameter ( After adding a hydrocarbon compound having an SP value of 13.0 to 15.0 (MPa) ^1/2 , a crosslinking agent and an additional vinyl monomer are added and polymerized to obtain an average particle size of 1. Vinyl resin particles having a surface of ~ 200 µm and wrinkles can be easily obtained. Further, according to the present invention, in the polymerization step, the addition timing of the hydrocarbon compound having a solubility parameter of 13.0 to 15.0 (MPa) ^1/2 , the vinyl monomer, and the crosslinking agent is adjusted. It is possible to easily adjust the wrinkles formed on the surface of the resin particles, so that resin particles that can be adapted to the demands of the electrical, electronic, medical, chemical, cosmetics, and other industrial fields can be easily obtained. Can be provided.

The method for producing vinyl resin particles of the present invention (hereinafter sometimes simply referred to as resin particles) includes: (a) a liquid of vinyl monomer A containing a plasticizer composed of fatty acid esters in an aqueous medium. An aqueous dispersion preparation step for preparing an aqueous dispersion by dispersing droplets, and (b) a polymerization step for polymerizing the vinyl monomer A in the aqueous dispersion, the steps (a) and (b) To produce resin particles having an average particle diameter of 1 to 200 μm having wrinkles on the surface.
As a method for producing the resin particles of the present invention, an emulsion polymerization method, a suspension polymerization method, or the like can be used. Among them, the suspension polymerization method is preferable because the desired particle diameter can be easily obtained.
In this specification, although the said suspension polymerization method is demonstrated as an example, the vinyl-type resin particle which has a wrinkle on the resin particle surface naturally also in other polymerization methods based on the technique of this invention can be manufactured.

[Step (a)]
Step (a) in the production method of the present invention comprises preparing an aqueous dispersion by dispersing droplets of vinyl monomer A containing a plasticizer comprising a fatty acid ester in an aqueous medium to prepare an aqueous dispersion. It is a process.
In the aqueous dispersion preparation step, an aqueous medium, a suspending agent, an anionic surfactant, and the like are put into a container equipped with an emulsifying device, and then a vinyl monomer A, a plasticizer, a polymerization initiator, Add chain transfer agent. An aqueous dispersion is prepared by dispersing the vinyl monomer containing the plasticizer as fine droplets in an aqueous medium by high-shear stirring in an emulsifier.

(Aqueous medium)
Examples of the aqueous medium used in the present invention include deionized water and pure water.

(Vinyl monomer A)
Examples of the vinyl monomer A used in the present invention include alkyl esters having 1 to 10 carbon atoms of acrylic acid such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; C 1-10 alkyl esters of methacrylic acid such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate; styrene, α-methylstyrene, o-methylstyrene, m- Methylstyrene, p-methylstyrene, vinyltoluene, p-ethylstyrene, 2,4-dimethylstyrene, p-methoxystyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, 2, 4-dichlorostyrene, pn-hexyl Styrene, p- octyl styrene, styrene sulfonic acid, vinyl aromatic compounds such as sodium styrenesulfonate; acrylonitrile, methacrylonitrile group-containing unsaturated compounds such as nitrites and the like.
These vinyl monomers can be used singly or in combination of two or more depending on the intended use of the resin particles obtained.

In the present invention, since the wrinkles on the surface of the crosslinked resin particles are easily formed, the vinyl monomer A preferably contains a (meth) acrylic acid ester as a main component. Among (meth) acrylic acid esters, methyl (meth) acrylate is more preferable, and methyl methacrylate is more preferable. In addition, a main component means containing 50-100 weight% of (meth) acrylic acid ester in the vinyl-type monomer A, The said (meth) acrylic acid ester is acrylic acid ester or methacrylic acid ester. Refers to both. Hereinafter, similar expressions are also the same.
From this point of view, the vinyl monomer A particularly preferably contains α-methylstyrene. In this case, the blending amount of α-methylstyrene is preferably more than 0% by weight and 15% by weight or less with respect to the vinyl monomer A.

(Fatty acid esters)
Fatty acid esters are used as the plasticizer, and the plasticizer is a component necessary for forming wrinkles on the surface of the resin particles. As will be described later, the hydrocarbon compound dissolved in the vinyl monomer is phase-separated from the polymer because its solubility changes with the polymerization of the monomer, and soot is formed. However, at this time, the viscosity of the polymer can be adjusted to a proper viscosity range for forming wrinkles with fatty acid esters as plasticizers.
Examples of the fatty acid esters include hexadecyl 2-ethylhexanoate, methyl palm fatty acid, methyl laurate, isopropyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, beef tallow fatty acid methyl, octyldodecyl myristate, methyl stearate, stearin Butyl acid, 2-ethylhexyl stearate, isotridecyl stearate, methyl caprate, methyl myristate, methyl oleate, isobutyl oleate, octyl oleate, lauryl oleate, oleyl oleate, myristyl myristate, stearyl stearate, olein Esters of fatty acids and monohydric alcohols such as 2-ethylhexyl acid, decyl oleate, isobutyl oleate; sorbitan monolaurate, sorbitan mono Lumitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol distearate, pentaerythritol monostearate, Examples include esters of fatty acids and polyhydric alcohols such as glycerin monostearate, glycerin distearate, glycerin tristearate, glycerin monooleate, glycerin tri-2-ethylhexanoate, cured beef tallow, and cured castor oil. Moreover, these fatty acid esters can be used alone or in combination.
Among these fatty acid esters, it is preferable to use glycerin tristearate because resin particles having wrinkles on the surface can be easily obtained.

The addition amount of the fatty acid esters (when using a plurality of fatty acid esters, the total addition amount thereof) is 0.1 to 3 parts by weight, preferably 0, per 100 parts by weight of the vinyl monomer A. 3 to 2 parts by weight. Within this range, the viscosity of the polymer can be adjusted to a viscosity range suitable for the formation of wrinkles, so that wrinkles can be easily formed on the resulting resin particle surfaces. If it is less than 0.1 part by weight, the object of forming wrinkles on the surface of the resin particles cannot be achieved. On the other hand, if it exceeds 3 parts by weight, the resin particles aggregate.
The method for adding the fatty acid esters is not particularly limited, but a method in which a predetermined amount is added and dissolved in advance in the vinyl monomer A used for the polymerization is preferable.

(Polymerization initiator, chain transfer agent)
Examples of the polymerization initiator used in the present invention include azo compounds such as azobisisobutyronitrile, cumene hydroperoxide, dicumyl peroxide, t-butylperoxy-2-ethylhexanoate, t- Examples include initiators soluble in monomers such as butyl peroxybenzoate, benzoyl peroxide, t-butyl peroxyisopropyl carbonate, lauroyl peroxide. Usually, the amount of the polymerization initiator is preferably 0.01 to 3 parts by weight with respect to 100 parts by weight of the total weight of the charged vinyl monomers (total of A and B).
In the present invention, for example, a chain transfer agent such as n-dodecyl mercaptan or α-methylstyrene dimer may be appropriately added to the vinyl monomer A in order to adjust the molecular weight of the obtained resin particles.

(Suspending agent)
Examples of the suspending agent added in the present invention include tricalcium phosphate, hydroxyapatite, magnesium pyrophosphate, magnesium phosphate, aluminum hydroxide, ferric hydroxide, titanium hydroxide, magnesium hydroxide, and phosphorus. Examples thereof include particulate water-insoluble inorganic salts such as barium acid, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, talc, kaolin and bentonite. These may be used alone or in combination of two or more, but are preferably tricalcium phosphate, hydroxyapatite, and magnesium pyrophosphate.
The amount of the suspension used is usually preferably 0.05 to 20 parts by weight, more preferably 0.3 to 15 parts by weight, based on 100 parts by weight of the aqueous medium in the aqueous dispersion. . If the added amount of the suspending agent is too small, the vinyl monomer A cannot be suspended and stabilized, and a lump of resin may be generated. This is not only undesirable from the viewpoint, but also tends to cause a problem that the particle size distribution becomes wide.

(Anionic surfactant)
Examples of the anionic surfactant added in the present invention include sodium alkyl sulfonate, sodium alkyl benzene sulfonate, sodium lauryl sulfate, sodium α-olein sulfonate, sodium dodecylphenyl oxide disulfonate, and the like. These may be used alone or in combination of two or more, preferably an alkali metal salt of an alkyl sulfonic acid having 8 to 20 carbon atoms (preferably a sodium salt), more preferably lauryl. A sulfonic acid alkali metal salt (preferably a sodium salt). Thereby, the effect of the outstanding suspension stabilization is acquired. Moreover, electrolytes, such as inorganic salts, such as lithium chloride, potassium chloride, sodium chloride, sodium sulfate, sodium nitrate, sodium carbonate, sodium hydrogencarbonate, can be added to an aqueous dispersion as needed.

[Step (b)]
Step (b) in the production method of the present invention is a polymerization step in which the vinyl monomer A in the aqueous dispersion prepared in step (a) is polymerized.
In the polymerization step, for example, the aqueous dispersion prepared in the step (a) is put into a reactor equipped with a stirrer, oxygen in the reactor is removed by nitrogen replacement, and then the reactor is stirred. And the vinyl monomer is polymerized at a predetermined temperature for a predetermined time.
The average particle diameter of the resin particles obtained by the production method of the present invention is 1 to 200 μm. In order to adjust the average particle size within this range, the dispersion state of the vinyl monomer A may be controlled by the type and amount of an anionic surfactant added to the aqueous dispersion, stirring conditions, and the like. . As a matter of course, the average particle diameter can be adjusted by classifying the obtained resin particles.
The average particle diameter of the resin particle in this specification means a volume average particle diameter. The volume average particle diameter is determined as the particle diameter when the resin particles are dispersed in water and the particle size distribution is measured by a laser diffraction scattering method, and the cumulative volume with respect to the volume of all particles is 50%. As the measuring device, for example, “Microtrack MT-3300EX” manufactured by Nikkiso Co., Ltd. can be used.

In order to obtain resin particles having wrinkles on the surface, as described in the step (a), using the vinyl monomer A containing a plasticizer composed of fatty acid esters in a predetermined ratio, the droplets It is necessary to prepare a dispersed aqueous dispersion, and in the step (b), a solubility parameter (SP value) of 13 is obtained when the polymerization conversion rate of the vinyl monomer A is 50 to 80%. 1.0 to 15.0 (MPa) ^1/2 of a hydrocarbon compound is added to the reaction system, and then the vinyl monomer B and the crosslinking agent are added to the reaction system. It needs to be 1 to 10 parts by weight with respect to 100 parts by weight of the vinyl monomer A.

(Hydrocarbon compounds)
In the polymerization step, the solubility parameter (SP value) of 13.0 to 15.0 (MPa) ^1/2 that acts together with the fatty acid esters as a hydrocarbon compound (deforming agent) for forming soot Hydrocarbon compounds are used. Examples of the hydrocarbon compound having an SP value of 13.0 to 15.0 (MPa) ^1/2 include butane, pentane, hexane, limonene and the like, and these may be used alone or in combination of two or more. Among them, pentane is particularly preferable from the viewpoint of compatibility with the vinyl monomer.
In the case of a hydrocarbon compound having an SP value of less than 13.0 (MPa) ^1/2 or more than 15.0 (MPa) ^1/2 , phase separation described later hardly occurs, and resin particles having wrinkles on the surface cannot be obtained. .
The SP value in this specification corresponds to the square root of the cohesive energy density between molecules, and this value is necessary for physically evaporating a 1 cm ³ liquid as shown in the following formula (1). It is a numerical value indicating the magnitude of the polarity per unit volume by a value obtained by raising the energy amount to a power of 1/2. SP value in this specification shall be a value calculated | required based on following (1) Formula.
SP value (MPa) ^1/2 = (ΔE / V) ^1/2 = ((ΔH−RT) / V) ^1/2
= ((ΔH−RT) d / M) ^1/2 (1)
ΔE: evaporation energy (J / mol), V: molecular volume (cm ³ / mol), ΔH: latent heat of vaporization (J / mol), R: gas constant = 8.314 J / (mol · K), T: absolute temperature (K), d: density (g / cm ³ ), M: molecular weight (g / mol)

The amount of the hydrocarbon compound added to the reaction system is preferably 10 to 40 parts by weight, and more preferably 15 to 30 parts by weight with respect to 100 parts by weight of the vinyl monomer A. When the addition amount of the hydrocarbon compound is too small relative to 100 parts by weight of the vinyl monomer A, phase separation described later is unlikely to occur, and resin particles having wrinkles on the surface may not be obtained. If the amount of the hydrocarbon compound added is too large, the suspension system may become unstable and resin particles may not be obtained.
Moreover, it is preferable that the boiling point of the hydrocarbon compound used by this invention is less than 60 degreeC. When the boiling point is less than 60 ° C., the hydrocarbon compound can be easily removed from the obtained resin particles, and the remaining of the hydrocarbon compound in the resin particles can be suppressed as much as possible.
The In the polymerization step, polymerization conversion 50% to 80% of vinyl monomer A, preferably 60 to 80% of the state, solubility parameter (SP value) of from 13.0 to 15.0 (MPa) ¹ After adding the ^{/ 2} hydrocarbon compound, the vinyl monomer B and the crosslinking agent are added.
When a hydrocarbon compound is added when the polymerization conversion is less than 50% or exceeds 80%, resin particles having wrinkles on the surface cannot be obtained.

The specific temperature and time reaction condition adjustment for adding the hydrocarbon compound to the reaction system to achieve a polymerization conversion of 50 to 80% is generally determined by the blending of various components, the polymerization conditions, and the like. For example, after raising the temperature to about 80 ° C. at about 0.4 to 0.8 ° C./min and then raising the temperature to about 115 ° C. at about 0.05 to 0.15 ° C./min, the temperature Can be adjusted by holding with stirring for about 3 to 9 hours.
In addition, as a method of adding the hydrocarbon compound, the vinyl monomer B, and the crosslinking agent to the reaction system, they may be supplied continuously or intermittently. Specifically, the addition rate is preferably 10 ml / min or less with a metering pump. If the addition rate exceeds 10 ml / min, the suspension system may become unstable and resin particles may not be obtained.

In addition, the polymerization conversion rate in this invention can be calculated | required as follows.
About 5 g of the soot-like polymer is taken out from the reactor before the hydrocarbon compound is added to the filter paper, the polymer is lightly pressed with the filter paper, and moisture is sucked into the filter paper. About 1.5 g of cocoon-shaped polymer is taken from a filter paper in a 20 ml beaker and weighed (g) to 4 digits after the decimal point to obtain “weight before reprecipitation”.
It is then dissolved in 5-6 ml of chloroform per gram of polymer (100% purity). 120-130 ml of methanol is put into a separately prepared 200 ml beaker, and the previously prepared chloroform solution is dropped little by little into the beaker containing methanol while stirring with a stirrer chip. Finally, 10 ml of methanol is poured into a 20 ml beaker, the polymer attached to the vessel wall is collected, and the solution is added to the 200 ml beaker. The solution in the 200 ml beaker is then stirred for several hours and then filtered to recover the polymer. The recovered polymer is air-dried and then dried in a vacuum dryer at 80 ° C. for 1 day or longer. The recovered amount of the polymer obtained by this operation is weighed (g) to 4 digits after the decimal point to obtain “weight after reprecipitation”.
By substituting the “weight before reprecipitation” and “weight after reprecipitation” obtained as described above into the following equation (2), the polymerization conversion rate (%) can be obtained.
Polymerization conversion rate (%) = (“weight after reprecipitation” / “weight before reprecipitation”) × 100 (2)

  In the present invention, the mechanism by which vinyl-based resin particles having wrinkles on the surface is obtained is not clear, but the hydrocarbon compound dissolved in the monomer phase changes in solubility as the polymerization proceeds, so that phase separation occurs. It is inferred that it will be a habit. In the present invention, in order to control the state of phase separation, α-methylstyrene or α-methylstyrene dimer is used to control the polymerization rate and polymer viscosity, but the chain other than α-methylstyrene dimer is used. It is also possible to suppress the state of phase separation by using a transfer agent, or changing the type, amount, or polymerization temperature condition of the polymerization initiator.

(Vinyl monomer B)
In the present invention, cross-linked resin particles are produced by adding a cross-linking agent. However, as the cross-linking of the polymer proceeds, the solubility of the hydrocarbon compound in the polymer changes, and soot is formed. Disappear. Therefore, by adding a specific amount of vinyl monomer B in the polymerization step, the solubility of the hydrocarbon compound in the polymer is adjusted to a range suitable for the formation of soot.
Examples of the vinyl monomer B to be added include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-ethylstyrene, 2,4-dimethylstyrene, p- Methoxystyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, 2,4-dichlorostyrene, pn-hexylstyrene, p-octylstyrene, styrenesulfonic acid, sodium styrenesulfonate Vinyl aromatic compounds such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and other alkyl esters having 1 to 10 carbon atoms; methyl methacrylate, methacrylic acid Ethyl, propyl methacrylate, methacrylic acid Chill, alkyl esters of the carbon atoms of methacrylic acid such as 2-ethylhexyl methacrylate is 1 to 10; acrylonitrile, methacrylonitrile group-containing unsaturated compounds such as nitrites and the like. These may be used individually by 1 type, and may be used in combination of 2 or more types.
In the present invention, since the vinyl monomer B is easy to adjust the solubility of the hydrocarbon compound as described above, it is preferable that the vinyl monomer B is mainly composed of a vinyl aromatic compound. It is more preferable that the main component is. In this case, the main component means that 50 to 100% by weight of the vinyl aromatic compound is contained in the vinyl monomer B.
When a vinyl monomer other than the vinyl aromatic compound is used in combination, the vinyl monomer is preferably a (meth) acrylic acid ester, and more preferably methyl methacrylate.
The amount of the vinyl monomer B to be added is 1 to 10 parts by weight and 3 to 8 parts by weight with respect to 100 parts by weight of the vinyl monomer A used in the step (a). preferable. If the addition amount of the vinyl monomer B is less than 1 part by weight or more than 10 parts by weight, resin particles having wrinkles on the surface cannot be obtained.

(Crosslinking agent)
As the crosslinking agent, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, (meth) acrylic monomers such as pentaerythritol tetra (meth) acrylate, divinylbenzene, Crosslinkable monomers such as aromatic divinyl compounds such as divinylnaphthalene can be used. These crosslinking agents may be used alone or in combination of two or more. Of these, divinylbenzene is particularly preferred from the viewpoint of compatibility with vinyl monomers.
The amount of the crosslinking agent to be added is preferably 0.5 to 20 parts by weight and preferably 2 to 10 parts by weight with respect to 100 parts by weight of the vinyl monomer A used in the step (a). More preferred. When the amount of the crosslinking agent is in the range of 0.5 to 20 parts by weight, the suspension system is less likely to become unstable, and resin particles having a wrinkle-like surface can be obtained.
Further, the vinyl monomer B and the cross-linking agent are added to a mixed solution containing water and an emulsifier, and stirred in an emulsifying apparatus (for example, at a rotation speed of 10,000 rpm for 5 minutes or more) to emulsify with water. It is preferable to add as. About the water and emulsifier used when making it into an emulsion, when the sum total of the vinyl-type monomer B and the crosslinking agent to add is 100 weight part, about 10-100 weight part water and 0.01-1 An anionic surfactant of about part by weight is preferred.

In the present invention, the vinyl monomer B and the crosslinking agent are added after the hydrocarbon compound is added. When the vinyl monomer B and the crosslinking agent are added before the hydrocarbon compound, a crosslinking reaction occurs before the hydrocarbon compound dissolves in the polymer. Therefore, the solubility of the hydrocarbon compound in the polymer, and the polymer Since the viscosity of the resin cannot be adjusted to an appropriate range for forming wrinkles, wrinkles are not formed. Further, when the vinyl monomer B and the crosslinking agent are added simultaneously with the hydrocarbon compound, the resin particles are condensed.
In order to easily form wrinkles on the surface of the resin particles, the addition of the vinyl monomer B and the crosslinking agent is such that after the addition of the hydrocarbon compound, the polymerization conversion is 2 to 2 more than the polymerization conversion at the time of adding the hydrocarbon compound. It is preferable to carry out when 40% has progressed (however, the polymerization conversion rate when the vinyl monomer B and the cross-linking agent are added is less than 100%), and when 3-20% has progressed. More preferably, it is more preferably carried out at a point of progress of 4 to 15% (however, the polymerization conversion rate when the vinyl monomer B and the crosslinking agent are added is less than 100%).

The resin particles thus formed are taken out from the reaction-finished liquid by known solid-liquid separation means such as filtration and centrifugation, and after removing the suspending agent adhering to the surface, washing and drying treatment are performed. For example, vinyl resin particles having an average particle diameter in the range of 1 to 200 μm as shown in FIG. In addition, the wrinkle referred to in the present invention means that the particle surface is not smooth and has a random curved uneven shape on the particle surface at least 10% with respect to the entire surface. Preferably it is 30% or more, more preferably 50% or more. Further, the difference between the height of the convex part of the curved concavo-convex shape and the depth of the concave part depends on the particle diameter of the resin particles, but is usually about 0.01 to 2 μm, preferably 0.1 to 1.5 μm. And it is a depth of 0.1 to 10% with respect to the average particle diameter. In the present invention, the difference in height between the convex and concave portions of the curved concavo-convex shape is referred to as “the depth of the ridge”. Such wrinkles can be confirmed with a scanning electron microscope or an atomic force microscope.
Specifically, the depth of the ridge is measured as follows. Vinyl resin particles are photographed using a nanoscale hybrid microscope, and the depth of wrinkles on the surface of the resin particles is measured by the amount of deflection of the cantilever at any 20 locations. The arithmetic average value of the measured values at the 20 locations is taken as the average depth of the wrinkles.
Next, the degree of swelling of the resin particles obtained by the method of the present invention will be described in detail.
The degree of swelling of the resin fine particles is an index representing the degree of crosslinking of the resin particles. The smaller the value, the higher the degree of crosslinking, and the larger the value, the lower the degree of crosslinking. In addition, it is preferable that the swelling degree of the resin particle of this invention is 0-20.
The degree of swelling can be measured as follows. Weigh precisely 1 g of resin particles in a graduated cylinder, tapping several times, and then gently transfer the solvent that can dissolve and swell the non-crosslinked portion of the resin particles at room temperature, such as toluene, at the room temperature. Add up to 50 ml. Then, let stand at 25 ° C. for 24 hours, read the height of the swollen gel in ml,
Swelling degree [−] = (reading value [ml] × 0.5 [g / ml]) / sampled amount [g]. In the above formula, 0.5 [g / ml] is the bulk density of the resin particles.
Such vinyl resin particles are useful in the electrical, electronic, medical, chemical, cosmetic and other industrial fields.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, the various characteristics in each example were calculated | required according to the method shown below.
(1) Volume average particle diameter (d50): measurement of 50% particle diameter of resin particles Resin particles are dispersed in water, and laser diffraction scattering method (“Microtrack MT-3300EX” (trade name) manufactured by Nikkiso Co., Ltd.) is used. The particle size distribution was measured, and the particle size when the cumulative volume with respect to the volume of all particles was 50% was determined as the 50% particle size. The shape factor of the particles was non-spherical.
(2) Dispersity (d90 / d10): Measurement of ratio of 90% particle diameter to 10% particle diameter of resin particles The resin particles are dispersed in water, and laser diffraction scattering method (“Microtrack MT-3300EX manufactured by Nikkiso Co., Ltd.) is used. (Trade name)), the particle size distribution is 10% and 90% when the cumulative volume with respect to the volume of all particles is 10% and 90%, respectively. The value divided by 10% particle size was used. The shape factor of the particles was non-spherical.
(3) Surface shape of resin fine particles For confirmation of the particle surface shape, the surface of the resin particles was photographed using a scanning electron microscope “VE7800” (trade name) manufactured by Keyence as a measuring device, and the presence or absence of wrinkles was confirmed. .
(4) Average depth of wrinkles Vinyl resin particles were photographed at a magnification of 1250 times using a nanoscale hybrid microscope (VN8000 (trade name) manufactured by Keyence Co., Ltd.). Measure the depth of wrinkles by the amount of deflection of the cantilever. The arithmetic average value of the measured values at 20 locations was defined as the average depth of the wrinkles.
(5) Swelling degree of resin particles 1 g of resin particles are precisely weighed in a measuring cylinder, tapped several times, and then toluene is gently transferred along the wall surface to 50 ml. Then, let stand at 25 ° C. for 24 hours, read the height of the swollen gel in ml,
The degree of swelling [−] = (reading value [ml] × 0.5 [g / ml]) / sampled amount [g] was calculated.
(6) Measurement of total light transmittance and haze of diffusive film A 50 mm x 50 mm sample piece was cut out from the light diffusing film, and the total light transmittance was measured with a haze meter ("NDH5000" (trade name) manufactured by Nippon Denshoku). And measured haze.

Example 1
1 kg of deionized water was put into a 3 L reactor (autoclave) equipped with a stirring blade, and 16.2 g of sodium pyrophosphate was added and dissolved, and then 37.5 g of powdered magnesium nitrate hexahydrate was added. In addition, the mixture was stirred at room temperature for 30 minutes to synthesize a magnesium pyrophosphate slurry as a suspending agent.
Next, to this reaction product-containing slurry, 5 g of a 10% by weight aqueous solution of sodium lauryl sulfonate and 375 g of methyl methacrylate as a vinyl monomer A, 90 g of styrene and 35 g of α-methylstyrene in advance as a polymerization initiator Benzoyl (Nippa Oil & Fats Co., Ltd. “Niper BW” (trade name), water diluted powder product) 2.5 g, t-butyl peroxy 2-ethylhexyl carbonate 0.67 g, α-methylstyrene dimer (Nippon Yushi) as chain transfer agent After adding 1 g of “NOFMER MSD” (trade name) manufactured by the company and 5 g of glycerin tristearate (beef fat hardened oil from Nippon Oil & Fats Co., Ltd.) as a plasticizer fatty acid ester, the mixed solution was homogenized. (M Technique Co., Ltd.), stirring for 10 minutes at 10,000 rpm, vinyl in water Monomer A was finely dispersed.

Next, after the inside of the autoclave was purged with nitrogen, the temperature was raised while stirring the stirring blade at 200 rpm, and the temperature was raised to 80 ° C. (polymerization start temperature) over 1 hour and a half. After reaching 80 ° C., the temperature was raised to 115 ° C. over 6.5 hours, maintained at 115 ° C. for 5 hours, and then cooled to 30 ° C. over about 6 hours. Four hours and 30 minutes after reaching 80 ° C. (polymerization start temperature), 75 g of pentane (a mixture of 80% n-pentane and 20% isopentane) was added as a hydrocarbon compound (deforming agent) for about 10 minutes and added to the autoclave. Next, 5 hours after reaching 80 ° C. (polymerization start temperature), the previously prepared emulsion was added for about 20 minutes and added to the autoclave. This emulsion is obtained by adding 30 g of styrene as a vinyl monomer B and 20 g of divinylbenzene as a cross-linking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate, and adding it to a homogenizer (manufactured by M Technique). The vinyl monomer B is finely dispersed in water by stirring for 5 minutes at a rotational speed of 10,000 rpm.
After cooling, the contents were taken out, 25 ml of nitric acid (67.5% by weight) was added, and the mixture was stirred for 15 minutes to dissolve the suspending agent attached to the surface of the resin particles. Thereafter, dehydration and washing were performed with a centrifuge, and moisture was removed with a vacuum dryer to obtain resin particles.
In addition, the microscope picture of the resin particle obtained in Example 1 is shown in FIG.

Example 2
60 g of pentane (a mixture of 80% n-pentane and 20% isopentane) was used as the hydrocarbon compound (deforming agent) and added over 20 minutes 4 hours after reaching 80 ° C. (polymerization start temperature). Resin particles were obtained in the same manner as in Example 1 except that the emulsion prepared in advance was applied for about 20 minutes after 4 hours and 30 minutes from the arrival at 0 ° C. (polymerization start temperature) and added to the autoclave. It was. This emulsion was prepared by adding 30 g of styrene as a vinyl monomer B and 20 g of divinylbenzene as a cross-linking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. ), The vinyl monomer B is finely dispersed in water by stirring at 10000 rpm for 5 minutes.
In addition, the microscope picture of the resin particle obtained in Example 2 is shown in FIG.

Example 3
125 g of pentane (a mixture of 80% n-pentane and 20% isopentane) is used as a hydrocarbon compound (deforming agent), added over 20 minutes 3 hours 30 minutes after reaching 80 ° C. (polymerization start temperature), then 4 hours after reaching 80 ° C. (polymerization start temperature), the emulsion prepared in advance was applied for about 20 minutes, and the same procedure was performed as in Example 1 except that the emulsion was added to the autoclave to obtain resin particles. It was. This emulsion was prepared by adding 30 g of styrene as a vinyl monomer B and 20 g as a cross-linking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. The vinyl monomer B is finely dispersed in water by stirring for 5 minutes at a rotational speed of 10,000 rpm.
In addition, the microscope picture of the resin particle obtained in Example 3 is shown in FIG.

Example 4
The same procedure as in Example 1 was carried out except that 5 g of glycerin monostearate was used as the fatty acid ester of the plasticizer and 150 g of butane (a mixture of 70% n-butane and 30% isobutane) was used as the hydrocarbon compound (deformer). Resin particles were obtained.

Example 5
1 kg of deionized water was put into a 3 L reactor (autoclave) equipped with a stirring blade, and 16.2 g of sodium pyrophosphate was added and dissolved, and then 37.5 g of powdered magnesium nitrate hexahydrate was added. In addition, the mixture was stirred at room temperature for 30 minutes to synthesize a magnesium pyrophosphate slurry as a suspending agent.
Next, to this reaction product-containing slurry, 5 g of a 10% by weight aqueous solution of sodium lauryl sulfonate, 465 g of methyl methacrylate as vinyl monomer A in advance and 35 g of α-methylstyrene were added to benzoyl peroxide as a polymerization initiator (Japan). “Nyper BW” (trade name) manufactured by Yushi Co., Ltd., 2.5 g of water-diluted powder product, 0.67 g of t-butylperoxy 2-ethylhexyl carbonate, α-methylstyrene dimer (manufactured by Nippon Yushi Co., Ltd. “ 1 g of NOFMER MSD "(trade name)), and a solution in which 10 g of 2-ethylhexanoic acid triglyceride (" EXEPEARL TGO "(trade name) manufactured by Kao Co., Ltd.) as a plasticizer fatty acid ester are dissolved, and then the mixed solution Was stirred with a homogenizer (manufactured by M-Technique) at a rotational speed of 10,000 rpm for 10 minutes. The vinyl monomer A was finely dispersed in the mixture.

Next, after the inside of the autoclave was purged with nitrogen, the temperature was raised while stirring the stirring blade at 200 rpm, and the temperature was raised to 80 ° C. (polymerization start temperature) over 1 hour and a half. After reaching 80 ° C., the temperature was raised to 115 ° C. over 6.5 hours, maintained at 115 ° C. for 5 hours, and then cooled to 30 ° C. over about 6 hours. 4 hours and 30 minutes after reaching 80 ° C. (polymerization start temperature), 75 g of decane was added as a hydrocarbon compound (deformer) for about 10 minutes and added to the autoclave. Next, 5 hours after reaching 80 ° C. (polymerization start temperature), the previously prepared emulsion was added for about 20 minutes and added to the autoclave. This emulsion was prepared by adding 10 g of methyl methacrylate as vinyl monomer B, 20 g of styrene and 30 g of divinylbenzene as a crosslinking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. (Manufactured by Technic Co., Ltd.), and the vinyl monomer B is finely dispersed in water by stirring at 10,000 rpm for 5 minutes.
After cooling, the contents were taken out, 25 ml of nitric acid (67.5% by weight) was added, and the mixture was stirred for 15 minutes to dissolve the suspending agent attached to the surface of the resin particles. Thereafter, dehydration and washing were performed with a centrifuge, and moisture was removed with a vacuum dryer to obtain resin particles.

Example 6
1 kg of deionized water was put into a 3 L reactor (autoclave) equipped with a stirring blade, and 16.2 g of sodium pyrophosphate was added and dissolved, and then 37.5 g of powdered magnesium nitrate hexahydrate was added. In addition, the mixture was stirred at room temperature for 30 minutes to synthesize a magnesium pyrophosphate slurry as a suspending agent.
Next, to this reaction product-containing slurry, 5 g of a 10% by weight aqueous solution of sodium lauryl sulfonate and 300 g of methyl methacrylate as a vinyl monomer A, 165 g of styrene, and 35 g of α-methylstyrene were previously oxidized as a polymerization initiator. Benzoyl (Nippa Oil & Fats Co., Ltd. “Niper BW” (trade name), water diluted powder product) 2.5 g, t-butyl peroxy 2-ethylhexyl carbonate 0.67 g, α-methylstyrene dimer (Nippon Yushi) as chain transfer agent 1 g of “NOFMER MSD” (trade name) manufactured by the company, and 12.5 g of sorbitan monooleate (“Emazole O10 (F)” (trade name) manufactured by Kao) as a plasticizer fatty acid ester are added. After that, the mixed solution was homogenized with a homogenizer (manufactured by M Technique) at a rotation speed of 10,000 rpm for 10 minutes. With stirring, the vinyl monomer A was finely dispersed in water.

Next, after the inside of the autoclave was purged with nitrogen, the temperature was raised while stirring the stirring blade at 200 rpm, and the temperature was raised to 80 ° C. (polymerization start temperature) over 1 hour and a half. After reaching 80 ° C., the temperature was raised to 115 ° C. over 6.5 hours, kept as it was for 115 hours, and then cooled to 30 ° C. over about 6 hours. Four hours and 30 minutes after reaching 80 ° C. (polymerization start temperature), 75 g of pentane (a mixture of 80% n-pentane and 20% isopentane) was added as a hydrocarbon compound (deforming agent) for about 10 minutes and added to the autoclave. Next, 5 hours after reaching 80 ° C. (polymerization start temperature), the previously prepared emulsion was added for about 20 minutes and added to the autoclave. This emulsion was prepared by adding 10 g of methyl methacrylate as vinyl monomer B, 20 g of styrene and 20 g of divinylbenzene as a crosslinking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. (Manufactured by Technic Co., Ltd.), and the vinyl monomer B is finely dispersed in water by stirring at 10,000 rpm for 5 minutes.
After cooling, the contents were taken out, 25 ml of nitric acid (67.5% by weight) was added, and the mixture was stirred for 15 minutes to dissolve the suspending agent attached to the surface of the resin particles. Thereafter, dehydration and washing were performed with a centrifuge, and moisture was removed with a vacuum dryer to obtain resin particles.

Example 7
1150 g of deionized water was placed in a 3 L reactor (autoclave) equipped with a stirring blade, 18.6 g of sodium pyrophosphate was further added and dissolved, and then 43.1 g of powdered magnesium nitrate hexahydrate was added. In addition, the mixture was stirred at room temperature for 30 minutes to synthesize a magnesium pyrophosphate slurry as a suspending agent.
Next, this reaction product-containing slurry was polymerized into 5.8 g of a 10% by weight aqueous solution of sodium lauryl sulfonate and 262.5 g of methyl methacrylate, 63 g of styrene and 24.5 g of α-methylstyrene as the vinyl monomer A in advance. 1.75 g of benzoyl peroxide as an initiator (“NIPPER BW” (trade name) manufactured by NOF Corporation, water-diluted powder product), 0.47 g of t-butylperoxy 2-ethylhexyl carbonate, α- as a chain transfer agent A solution in which 0.7 g of methylstyrene dimer (“NOFMER MSD” (trade name) manufactured by NOF Corporation) and 3.5 g of glycerin tristearate (beef fat extremely hardened oil manufactured by NOF Corporation) as a fatty acid ester of a plasticizer are dissolved. Then, the mixed solution was stirred with a homogenizer (manufactured by M Technique) at a rotation speed of 10,000 rpm for 10 minutes. The mixture was stirred and the vinyl monomer A was finely dispersed in water.

Next, after the inside of the autoclave was purged with nitrogen, the temperature was raised while stirring the stirring blade at 200 rpm, and the temperature was raised to 80 ° C. (polymerization start temperature) over 1 hour and a half. After reaching 80 ° C., the temperature was raised to 115 ° C. over 6.5 hours, maintained at 115 ° C. for 5 hours, and then cooled to 30 ° C. over about 6 hours. 4 hours and 30 minutes after reaching 80 ° C. (polymerization start temperature), 52.5 g of pentane (a mixture of n-pentane 80% and isopentane 20%) is added as a hydrocarbon compound (deforming agent) for about 10 minutes and added to the autoclave. did. Next, 5 hours after reaching 80 ° C. (polymerization start temperature), the previously prepared emulsion was added for about 20 minutes and added to the autoclave. This emulsion was prepared by adding 21 g of styrene as vinyl monomer B and 14 g of divinylbenzene as a cross-linking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate, and adding it to a homogenizer (manufactured by M Technique). The vinyl monomer B is finely dispersed in water by stirring for 5 minutes at a rotational speed of 10,000 rpm.
After cooling, the contents were taken out, 25 ml of nitric acid (67.5% by weight) was added, and the mixture was stirred for 15 minutes to dissolve the suspending agent attached to the surface of the resin particles. Thereafter, dehydration and washing were performed with a centrifuge, and moisture was removed with a vacuum dryer to obtain resin particles.

Example 8
In a 3 L reactor (autoclave) equipped with a stirring blade, 1070 g of deionized water was added, and 17.3 g of sodium pyrophosphate was added and dissolved, and then 40.1 g of powdered magnesium nitrate hexahydrate was added. In addition, the mixture was stirred at room temperature for 30 minutes to synthesize a magnesium pyrophosphate slurry as a suspending agent.
Next, 5.4 g of a 10% by weight aqueous solution of sodium lauryl sulfonate and 322.5 g of methyl methacrylate as a vinyl monomer A, 77.4 g of styrene, and 30.1 g of α-methylstyrene were added to the reaction product-containing slurry. Benzoyl peroxide as a polymerization initiator (“Nyper BW” (trade name) manufactured by NOF Corporation, water diluted powder product) 2.2 g, 0.6 g of t-butylperoxy 2-ethylhexyl carbonate, as a chain transfer agent 0.9 g of α-methylstyrene dimer (“NOFMER MSD” (trade name) manufactured by NOF Corporation) and 4.3 g of glycerin tristearate (beef fat extremely hardened oil manufactured by NOF Corporation) as a plasticizer fatty acid ester are dissolved. Then, the mixed solution was stirred with a homogenizer (manufactured by M Technique) for 10 minutes at a rotation speed of 10,000 rpm. The mixture was stirred and the vinyl monomer A was finely dispersed in water.

Next, after the inside of the autoclave was purged with nitrogen, the temperature was raised while stirring the stirring blade at 200 rpm, and the temperature was raised to 80 ° C. (polymerization start temperature) over 1 hour and a half. After reaching 80 ° C., the temperature was raised to 115 ° C. over 6.5 hours, maintained at 115 ° C. for 5 hours, and then cooled to 30 ° C. over about 6 hours. 44.5 hours after reaching 80 ° C. (polymerization start temperature), 64.5 g of pentane (a mixture of n-pentane 80% and isopentane 20%) is added as a hydrocarbon compound (deforming agent) for about 10 minutes and added to the autoclave. did. Next, 5 hours after reaching 80 ° C. (polymerization start temperature), the previously prepared emulsion was added for about 20 minutes and added to the autoclave. This emulsion was prepared by adding 25.8 g of styrene as vinyl monomer B and 17.2 g of divinylbenzene as a cross-linking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. The vinyl monomer B is finely dispersed in water by stirring at 10000 rpm for 5 minutes.
After cooling, the contents were taken out, 25 ml of nitric acid (67.5% by weight) was added, and the mixture was stirred for 15 minutes to dissolve the suspending agent attached to the surface of the resin particles. Thereafter, dehydration and washing were performed with a centrifuge, and moisture was removed with a vacuum dryer to obtain resin particles.

Example 9
A hydrocarbon compound (deformation agent) was added over 10 minutes after reaching 80 ° C. (polymerization start temperature) over 10 minutes, and the emulsion emulsified with water was reached after 4 hours 30 minutes when reaching 80 ° C. (polymerization start temperature). Except having added over 20 minutes, it implemented similarly to Example 1 and obtained the resin particle.
Example 10
A hydrocarbon compound (amorphizing agent) was added over 10 minutes after reaching 80 ° C. (polymerization start temperature) for 10 minutes, and the emulsion emulsified with water was added 4 hours after reaching 80 ° C. (polymerization start temperature). Except having added over 20 minutes, it implemented similarly to Example 1 and obtained the resin particle.

Example 11
After adding a hydrocarbon compound (deformation agent), 6 g of styrene as vinyl monomer B and 20 g of divinylbenzene as a crosslinking agent are added to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate, and a homogenizer. (M Technique Co., Ltd.) and Example 1 except that the emulsion in which vinyl monomer B was finely dispersed in water was added to the autoclave with stirring at 10000 rpm for 5 minutes. In the same manner, resin particles were obtained.

Example 12
After adding a hydrocarbon compound (deformation agent), 47.5 g of styrene as vinyl monomer B and 20 g of divinylbenzene as a crosslinking agent are added to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. In Example, except that the homogenizer (manufactured by M Technique Co., Ltd.) was stirred for 5 minutes at a rotational speed of 10,000 rpm, and an emulsion in which the vinyl monomer B was finely dispersed in water was added to the autoclave. In the same manner as in No. 1, resin particles were obtained.

Example 13
A hydrocarbon compound (amorphizing agent) was added over 10 minutes 3 hours 30 minutes after reaching 80 ° C. (polymerization start temperature), and an emulsion emulsified with water was added 6 hours after reaching 80 ° C. (polymerization start temperature). Except having added over 20 minutes, it implemented similarly to Example 1 and obtained the resin particle.
Comparative Example 1
Resin particles were obtained in the same manner as in Example 1 except that the hydrocarbon compound (deforming agent) was not added. No wrinkles were formed on the surface of the obtained resin particles. In addition, the microscope picture of the resin particle obtained by the comparative example 1 is shown in FIG.

Comparative Example 2
1 kg of deionized water was put into a 3 L reactor (autoclave) equipped with a stirring blade, and 16.2 g of sodium pyrophosphate was added and dissolved, and then 37.5 g of powdered magnesium nitrate hexahydrate was added. In addition, the mixture was stirred at room temperature for 30 minutes to synthesize a magnesium pyrophosphate slurry as a suspending agent.
Next, to this reaction product-containing slurry, 5 g of a 10% by weight aqueous solution of sodium lauryl sulfonate and 300 g of methyl methacrylate as a vinyl monomer A, 165 g of styrene, and 35 g of α-methylstyrene were previously oxidized as a polymerization initiator. Benzoyl (Nippa Oil & Fats Co., Ltd. “Niper BW” (trade name), water diluted powder product) 2.5 g, t-butyl peroxy 2-ethylhexyl carbonate 0.67 g, α-methylstyrene dimer (Nippon Yushi) as chain transfer agent After adding 1 g of “NOFMER MSD” (trade name) manufactured by the company and 5 g of glycerin tristearate (beef fat hardened oil from Nippon Oil & Fats Co., Ltd.) as a plasticizer fatty acid ester, the mixed solution was homogenized. (M Technique Co., Ltd.), stirring for 10 minutes at 10,000 rpm, vinyl in water The system monomer A was finely dispersed.

Next, 75 g of pentane (a mixture of 80% n-pentane and 20% isopentane) as a hydrocarbon compound (a deforming agent) and an emulsion prepared in advance were added into the autoclave. This emulsion was prepared by adding 10 g of methyl methacrylate as vinyl monomer B, 20 g of styrene and 20 g of divinylbenzene as a crosslinking agent to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. (Manufactured by Technic Co., Ltd.), and the vinyl monomer B is finely dispersed in water by stirring at 10,000 rpm for 5 minutes.
Next, after the inside of the autoclave was purged with nitrogen, the temperature was raised while stirring the stirring blade at 200 rpm, and the temperature was raised to 80 ° C. (polymerization start temperature) over 1 hour and a half. After reaching 80 ° C., the temperature was raised to 115 ° C. over 6.5 hours, kept at 115 ° C. for 5 hours, and then cooled to 30 ° C. over about 6 hours.
After cooling, the contents were taken out, 25 ml of nitric acid (67.5% by weight) was added, and the mixture was stirred for 15 minutes to dissolve the suspending agent attached to the surface of the resin particles. Thereafter, dehydration and washing were performed with a centrifuge, and moisture was removed with a vacuum dryer to obtain resin particles. The obtained resin particles were agglomerated and were larger than 200 μm.

Comparative Example 3
A hydrocarbon compound (amorphizing agent) was added over 10 minutes after reaching 80 ° C. (polymerization start temperature) over 10 minutes, and the emulsion emulsified with water was added after 3 hours 30 minutes when reaching 80 ° C. (polymerization start temperature). Except having added over 20 minutes, it implemented similarly to Example 1 and obtained the resin particle. The surface of the obtained resin particles was depressed and no wrinkles were formed.
Comparative Example 4
A hydrocarbon compound (deformation agent) was added over 10 minutes 5 hours 30 minutes after reaching 80 ° C. (polymerization start temperature), and the emulsion emulsified with water was 6 hours after reaching 80 ° C. (polymerization start temperature). Except having added over 20 minutes, it implemented similarly to Example 1 and obtained the resin particle. The surface of the obtained resin particles was depressed and no wrinkles were formed.

Comparative Example 5
A hydrocarbon compound (deformation agent) was added over 10 minutes after reaching 80 ° C. (polymerization start temperature) for 10 minutes, and the emulsion emulsified with water was 7 hours after reaching 80 ° C. (polymerization start temperature). Except having added over 20 minutes, it implemented similarly to Example 1 and obtained the resin particle. No wrinkles were formed on the surface of the obtained resin particles.
Comparative Example 6
Resin particles were obtained in the same manner as in Example 1 except that 75 g of neopentane was used as the hydrocarbon compound (deformation agent). No wrinkles were formed on the surface of the obtained resin particles.
Comparative Example 7
Resin particles were obtained in the same manner as in Example 1 except that 75 g of heptane was used as the hydrocarbon compound (deformation agent). No wrinkles were formed on the surface of the obtained resin particles.

Comparative Example 8
Resin particles were obtained in the same manner as in Example 1 except that 75 g of xylene was used as the hydrocarbon compound (deformation agent). The obtained resin particles were agglomerated and were larger than 200 μm.
Comparative Example 9
Resin particles were obtained in the same manner as in Example 1 except that xylene was used in place of the fatty acid esters. The obtained resin particles were agglomerated and were larger than 200 μm.
Comparative Example 10
Except not using fatty acid ester, it implemented similarly to Example 1 and obtained the resin particle. No wrinkles were formed on the surface of the obtained resin particles.

Comparative Example 11
Resin particles were obtained in the same manner as in Example 1 except that 25 g of glycerin tristearate (Nippon Yushi Co., Ltd. beef tallow extremely hardened oil) was added as a fatty acid ester of a plasticizer. The obtained resin particles were agglomerated and were larger than 200 μm.
Comparative Example 12
After adding a hydrocarbon compound (deformation agent), 20 g of divinylbenzene as a cross-linking agent was added to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate, and the number of revolutions was increased with a homogenizer (M Technique). Stirring at 10,000 rpm for 5 minutes was carried out in the same manner as in Example 1 except that an emulsion in which the vinyl monomer B was finely dispersed in water was added to the autoclave to obtain resin particles. . No wrinkles were formed on the surface of the obtained resin particles.

Comparative Example 13
The emulsion emulsified with water was added over 4 hours 30 minutes after reaching 80 ° C (polymerization start temperature) over 20 minutes, and the hydrocarbon compound (deforming agent) was added 10 hours after reaching 80 ° C (polymerization start temperature). Except having been added over a period of time, the same procedure as in Example 1 was performed to obtain resin particles. No wrinkles were formed on the surface of the obtained resin particles.
Comparative Example 14
Carried out in the same manner as in Example 1 except that an emulsion emulsified with a hydrocarbon compound (a deforming agent) and water was added over 20 minutes after reaching 80 ° C (polymerization start temperature) for 4 hours and 30 minutes, Resin particles were obtained. The obtained resin particles were agglomerated and were larger than 200 μm.

Comparative Example 15
After adding a hydrocarbon compound (deformation agent), 55 g of styrene as vinyl-based monomer B and 20 g of divinylbenzene as a cross-linking agent are added to a dispersion of 30 g of pure water and 1 g of a 10% by weight aqueous solution of sodium lauryl sulfonate. (M Technique Co., Ltd.) and Example 1 except that the emulsion in which vinyl monomer B was finely dispersed in water was added to the autoclave with stirring at 10000 rpm for 5 minutes. In the same manner, resin particles were obtained. No wrinkles were formed on the surface of the obtained resin particles.
Tables 1 to 4 show the polymerization conditions, surface shape, average depth of wrinkles, swelling degree, d50, and dispersity (d90 / d10) of the resin particles obtained in Examples 1 to 13 and Comparative Examples 1 to 15. Shown in

  As is clear from Tables 1 to 4, the resin particles obtained in Examples 1 to 13 all have wrinkles on the surface, no condensation is observed, and the average particle diameter (d50) is 8 to 21 μm. It is in the range. On the other hand, the resin particles obtained in Comparative Examples 1 to 15 did not have wrinkles on the surface, and some of them were condensed.

Example 14
A predetermined amount (0.2 g, 0.5 g, 1 g) of the resin particles obtained in Example 1 is weighed. Each of the weighed resin particles and 10 g of binder resin (“Vaironal MD-1200” (trade name) manufactured by Toyobo Co., Ltd.) are stirred and mixed for 5 minutes, and a PET film (100 μm thick manufactured by Toray Industries, Inc. It was applied at a thickness of 100 μm to “Luminer 100T6” (trade name). Then, it heated at 80 degreeC with the dryer for 1 hour, and produced the light-diffusion film.
Example 15
A light diffusing film was produced in the same manner as in Example 14 except that the resin particles of Example 2 were used.
Example 16
A light diffusion film was produced in the same manner as in Example 14 except that the resin particles of Example 3 were used.
Comparative Example 16
A light diffusion film was produced in the same manner as in Example 14 except that the resin particles of Comparative Example 1 were used.
The optical properties of the light diffusion films obtained in Examples 14 to 16 and Comparative Example 16 were evaluated (total light transmittance and haze were measured). The results are shown in Table 5.
From these results, when the resin particles having wrinkles on the surface obtained in the present invention are used as a light diffusing agent, compared with the case where resin particles having a smooth surface are used, the same addition amount is obtained. It can be seen that a light diffusing film having a high haze is obtained while maintaining the total light transmittance, and when the light diffusing film having the same haze is produced, the amount of resin particles added can be reduced.

  The vinyl-based resin particles having wrinkles on the surface obtained by the present invention can be used for additives for light diffusing agents, cosmetics, paints, and the like, and can be used for various applications that take advantage of the functionality of having wrinkles. Is.

2 is a photomicrograph of resin particles obtained in Example 1. 2 is a photomicrograph of resin particles obtained in Example 2. 2 is a photomicrograph of resin particles obtained in Example 3. 2 is a photomicrograph of resin particles obtained in Comparative Example 1.

Claims (7)

(A) an aqueous dispersion preparation step of preparing an aqueous dispersion by dispersing droplets of the vinyl monomer A in an aqueous medium; and (b) a vinyl monomer A in the aqueous dispersion. A method for producing vinyl resin particles having an average particle diameter of 1 to 200 μm having wrinkles on the surface, including a polymerization step for polymerization,
(1) The droplet of the vinyl monomer A in the step (a) includes a plasticizer composed of an aliphatic ester, and the added amount of the plasticizer is 100 parts by weight of the vinyl monomer A. And 0.1 to 3 parts by weight,
(2) In the step (b), a hydrocarbon compound having a solubility parameter of 13.0 to 15.0 (MPa) ^{1/2 in} a state where the polymerization conversion rate of the vinyl monomer A is 50 to 80%. Adding to the polymerization reaction system, and (3) in the step (b), following the operation of (2) above, adding the vinyl monomer B and the crosslinking agent to the polymerization reaction system, The addition amount of the body B is 1 to 10 parts by weight with respect to 100 parts by weight of the vinyl monomer A,
A method for producing vinyl resin particles characterized by the above.   The method for producing vinyl resin particles according to claim 1, wherein the amount of the hydrocarbon compound added is 10 to 40 parts by weight with respect to 100 parts by weight of the vinyl monomer A.   The method for producing vinyl resin particles according to claim 1 or 2, wherein the hydrocarbon compound has a boiling point of less than 60 ° C.   The vinyl monomer A contains (meth) acrylic acid ester as a main component, and the vinyl monomer B contains a vinyl aromatic compound as a main component. The manufacturing method of the vinyl-type resin particle of description.   The method for producing vinyl resin particles according to claim 1, wherein the vinyl monomer A contains methyl (meth) acrylate and α-methylstyrene.   The method for producing vinyl-based resin particles according to any one of claims 1 to 5, wherein the crosslinking agent added in the step (b) is divinylbenzene.   The amount of the crosslinking agent added in the step (b) is 0.5 to 20 parts by weight with respect to 100 parts by weight of the vinyl monomer A. The production of vinyl resin particles according to any one of claims 1 to 6. Method.

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