JP5834856B2 - Resin particles and method for producing the same - Google Patents

Description

  The present invention relates to resin particles and a method for producing the same.

  The resin particles are used as a binder for toners, powder paints, slush molding materials and the like. Here, for example, in order to improve the strength of the resin particles, the fluidity of the powder, or to suppress packing, silica particles may be attached to the resin particles to functionalize the resin particles. Such a function is considered to depend on the shape and adhesion state of silica particles as external additives for the resin particles, and various shapes of silica particles and adhesion modes have been proposed.

For example, Patent Documents 1 and 2 disclose a powder coating using a resin particle having hydrophobic silica attached to the surface thereof.
For example, Patent Documents 3 to 5 disclose polyurethane resin particles containing silica particles.

JP-A-8-283617 Japanese Patent Laid-Open No. 9-143401 JP-A-4-255755 JP-A-6-41419 JP 2006-28319 A

  An object of the present invention is to provide resin particles having excellent aggregation resistance.

The above problem is solved by the following means. That is,
The invention according to claim 1 is a resin particle main body (A), silica mother particles, and silica core particles having an average circularity of 0.7 or more and 0.85 or less adhered to the surface of the silica mother particles. And silica particles (B) attached to the surface of the resin particle main body (A).

  The invention according to claim 2 is a step of preparing an alkali catalyst solution containing an alkali catalyst at a concentration of 0.8 mol / L or more and 1.0 mol / L or less in a solvent containing alcohol, and the prepared alkali catalyst In the solution, without additionally supplying the alkali catalyst, a step of supplying tetraalkoxysilane to obtain a concentration of 0.7 mol / L or more and 1.8 mol / L or less to obtain silica particles, and the obtained And a step of adhering silica particles to the surface of the resin particle main body.

  The invention according to claim 3 is characterized in that the tetraalkoxysilane is contained in the alkaline catalyst solution at a supply rate of 0.001 mol / (mol · min) or more and 0.010 mol / (mol · min) or less with respect to the alcohol. It is a manufacturing method of the resin particle of Claim 2 supplied to.

  According to the first aspect of the present invention, the silica particles adhering to the surface of the resin particle main body have an average circularity of 0.7 or more and 0.85 formed by adhering to the silica mother particles and the surface of the silica mother particles. Resin particles excellent in aggregation resistance are provided as compared with the case where the silica particles are not included.

  According to the invention according to claim 2, in the supply step of supplying tetraalkoxysilane so as to have a concentration of 0.7 mol / L or more and 1.8 mol / L or less in the alkali catalyst solution containing the alkali catalyst, As compared with the case where an alkali catalyst is additionally supplied, a method for producing resin particles having excellent aggregation resistance is provided.

  According to the invention of claim 3, tetraalkoxysilane is alkalinized at a supply rate of 0.001 mol / (mol · min) or more and 0.010 mol / (mol · min) or less with respect to the alcohol in the alkali catalyst solution. A method for producing resin particles having excellent agglomeration resistance as compared with the case where the catalyst solution is not supplied is provided.

The resin particles according to this embodiment are composed of a resin particle main body (A) and silica particles (B) attached to the surface of the resin particle main body (A).
Hereinafter, the resin particle main body (A) and the silica particles (B) constituting the resin particles will be described.
In the present specification, the “resin particle body” refers to resin particles to which silica particles (B) are not attached.

<Silica particles (B)>
First, the silica particles (B) according to this embodiment will be described.
The silica particles (B) include silica mother particles and silica child particles having an average circularity of 0.7 or more and 0.85 or less attached to the surface of the silica mother particles.
Since the above configuration is adopted, the silica child particles have a particle size smaller than that of the silica mother particles, that is, the silica particles (B) include at least two types of silica particles.

The silica child particles constituting the silica particles (B) have an average circularity of 0.7 or more and 0.85 or less.
Here, the circularity indicates the degree of sphere of the particle, and when the circularity is 1, it indicates that the particle is a true sphere.
Silica particles have an average circularity of 0.7 or more and 0.85 or less as a shape of primary particles, which means that the shape is more irregular than a true sphere, that is, an “irregular shape”. Hereinafter, a shape having a circularity of 0.85 or less is sometimes referred to as “an irregular shape (shape)”, whereas a shape having a circularity exceeding 0.85 is sometimes referred to as a “spherical shape”.
The silica particles (B) configured to include such irregularly shaped silica particles and silica mother particles having the silica particles adhered to the surface have a shape having irregularly shaped protrusions.

Attempts have been made to increase the fluidity of the resin particles by attaching silica particles to the surface of the resin particles. However, in the resin particles with silica particles attached as shown in the background art, when mechanical load is applied, the silica particles fall off from the resin particles, or the silica particles move on the surface of the resin particles. In some cases, the resin particles enter the recesses (dents) and become unevenly distributed, which may cause aggregation between the resin particles.
On the other hand, when the silica particles (B) having the protrusions adhere to the surface of the resin particle main body as in the present embodiment, it is considered that the following actions are obtained.
First, since the silica particles (B) have protrusions, a spike effect (hook effect) on the surface of the resin particle main body (A) is expressed, and a spacer effect is expressed between the silica particles (B). That is, the presence of the protrusions makes it difficult for the silica particles (B) to move or embed on the surface of the resin particle main body (A), and to cause aggregation of the silica particles (B). As a result, the silica particles (B) are prevented from being unevenly distributed on the surface of the resin particle main body (A). In particular, in this embodiment, since this protrusion is not spherical but has an irregular shape, the above-described spike effect and spacer effect are more greatly expressed, and the adherence of silica particles (B) to the resin particle body (A). And adhesion are increased, so that the uneven distribution of the silica particles (B) is suppressed regardless of the hardness and shape of the resin particle main body (A), and the resin particle main body (A) with the silica particles (B) attached to the surface thereof. Even when a mechanical load is applied, it is considered that the uneven distribution of the silica particles (B) is effectively suppressed.

From the above, in the resin particles comprising the resin particle main body (A) and the silica particles (B), the silica particles (B) adhered to the surface without being unevenly distributed are the resin particle main bodies (A). Therefore, it is considered that the contact area between the resin particle bodies (A) can be reduced and the state can be maintained.
As a result, it is presumed that the resin particles having the above-described configuration have high fluidity and can effectively suppress aggregation between the resin particles.
Moreover, it is considered that not only the resin particle main body (A) but also the aggregation between the resin particle main body (A) and other resin particles can be suppressed.

[Attachment mode of silica particles]
In the silica particles (B), the irregular shaped silica child particles described above are attached to the surface of the silica mother particles.
The state of adhesion between the silica child particles and the silica mother particles is not particularly limited, and for example, the silica child particles and the silica mother particles may be in a mechanically fixed state, or the silica child particles and the silica mother particles may be It may be in a state of being bonded by an adhesive or the like, or may be in a state in which a part of the silica child particles and a part of the silica mother particles are fused and integrally bonded.
Among these, from the viewpoint of the strength of silica particles and the suppression of detachment of silica particles, a part of silica particles and a part of silica mother particles are fused and bonded together. It is preferable.

-Coverage of silica particles (attachment amount)-
Moreover, it is preferable that the silica child particle is scattered evenly on the surface of the silica mother particle. The amount of silica particles attached to the surface of the silica mother particles is not particularly limited, but from the viewpoint of easily maintaining the adhesion to the resin particle main body (A), the coverage of the silica particles on the surface of the silica mother particles is 30% or more. Is preferred. From the viewpoint of facilitating biting of the silica child particles into the resin particle main body (A), the coverage of the silica child particles on the surface of the silica mother particles is preferably 90% or less.
The coverage of silica particles is determined by measuring the adhesion area of silica particles by image analysis using SEM, and the ratio of the total adhesion area a of silica particles to the surface area b of the silica mother particles [(a / b) × 100]. Calculated.
The coverage of the silica core particles on the surface of the silica mother particles is more preferably 42% or more and 75% or less.

[Physical properties of silica core particles and silica mother particles]
-Average circularity-
As described above, the silica particles constituting the silica particles (B) have an average circularity of primary particles of 0.7 or more and 0.85 or less.
When the average circularity of the silica particles exceeds 0.85, the primary particles become nearly spherical, so that the silica particles that are the protrusions of the silica particles (B) are not easily caught on the resin particle body (A), and the resin. Adhesion to the particle body is poor. Therefore, for example, when the silica particles (B) and the resin particle main body (A) are mixed and stirred, or after storage over time, the silica particles (B) are biased and adhere to the resin particle main body (A). It can be detached from the main body (A).
Further, when the average circularity of the silica child particles is less than 0.7, the particles have a large aspect ratio, and when the silica child particles are subjected to a mechanical load, stress concentration occurs and the particles tend to be lost. .
In addition, when manufacturing a silica particle (B) by the sol-gel method, the silica child particle whose average circularity of a primary particle is less than 0.7 is difficult on manufacture.
The average circularity of the silica child particles is more preferably 0.75 or more and 0.80 or less.

The circularity of the primary particles of the silica particles is analyzed using an image analysis software WinROOF (manufactured by Mitani Shoji Co., Ltd.) by analyzing an image of the primary particles of the silica particles adhering to the surface of the silica mother particles. It is obtained as “100 / SF2” calculated by the equation (1).
Circularity (100 / SF2) = 4π × (A / I ² ) (1)
[In Formula (1), I shows the perimeter length of the primary particle on an image, and A expresses the projection area of a primary particle. ]
The average circularity of the primary particles is obtained as 50% circularity in the cumulative frequency of the 100 primary particles obtained by the image analysis.

In addition, the image of the silica particle used for the said image analysis is specifically obtained as follows using an electron beam three-dimensional roughness analyzer (ERA-8900: made by Elionix).
First, silica particles (B) are dispersed and adhered to resin particles (polyester, weight average molecular weight Mw = 50,000) having a smooth surface and a volume average particle diameter of 100 μm. Using a three-dimensional roughness analyzer, the resin particles to which the silica particles (B) are attached are subjected to height analysis in the XY axis direction every 10 nm in a 10,000 × field of view. Get a numerical value. Next, the height analysis numerical values are imaged in a conditional format (two-color scale) using spreadsheet software Microsoft Excel (manufactured by Microsoft). By such imaging, a two-dimensional image of the child particles in which only the child particles having a height higher than that of the mother particles are lifted is obtained.

Moreover, it is preferable that the average circularity of the primary particle | grains as the whole silica particle (B) in which the silica child particle has adhered to the silica mother particle is 0.5-0.85.
When the average circularity of the primary particles of the silica particles (B) is 0.5 or more, a decrease in the strength of the silica particles (B) is suppressed, and the average circularity of the primary particles of the silica particles (B) is 0.00. It becomes easy to adhere a silica particle (B) to a resin particle main body because it is 85 or less.
The average circularity of the primary particles of the silica particles (B) is more preferably 0.6 or more and 0.75 or less.

The average circularity of the primary particles of the silica particles (B) is obtained by dispersing the primary particles after the silica particles (B) are dispersed in resin particles (polyester, weight average molecular weight Mw = 50000) having a volume average particle size of 100 μm. It is obtained as “100 / SF2” calculated by the above-described equation (1) from the planar image analysis of the primary particles obtained by observation with the SEM apparatus.
The average circularity of the primary particles of the silica particles (B) is obtained as 50% circularity in the cumulative frequency of 100 primary particles obtained by the planar image analysis.

-Particle size-
The silica child particles are not particularly limited as long as the particle size is smaller than that of the silica mother particles. However, from the viewpoint of easy penetration of the silica child particles into the resin particle main body (A), the particle size of the silica child particles is It is preferably 10% or more and 40% or less of the particle size of the particles.
When the particle size of the silica child particles is 10% or more of the particle size of the silica mother particles, the silica child particles are not easily detached even if they bite into the resin particle main body (A). On the other hand, when the particle diameter of the silica child particles is 40% or less of the particle diameter of the silica mother particles, the silica child particles easily bite into the resin particle main body (A).

  Moreover, it is preferable that the particle diameter of a silica child particle is 10 nm or more and 200 nm or less. When the particle diameter of the silica child particles is 10 nm or more, the shape of the particles is hardly spherical, and the average circularity of the silica child particles is easily set to a shape of 0.7 to 0.85. Moreover, when making a silica child particle adhere to a silica mother particle, a silica child particle is easy to disperse | distribute on the silica mother particle surface. On the other hand, when the particle size of the silica child particles is 200 nm or less, the silica particles are hardly lost when a mechanical load is applied to the silica particles.

The particle diameters of the silica mother particles and the silica child particles are average values of equivalent circle diameters obtained by observing the silica particles (B) with a SEM apparatus and using the image analysis software WinROOF from the following formula (2). The average equivalent circle diameter is used.
Equivalent circle diameter = 2√ (area / π) (2)

Furthermore, it is preferable that the volume average particle diameter of the silica particles (B) including the silica mother particles and the silica child particles is 100 nm or more and 500 nm or less.
When the volume average particle diameter of the silica particles (B) is 100 nm or more, the silica particles (B) are easily dispersed on the surface of the resin particle main body (A). Further, since the volume average particle diameter of the silica particles (B) is 500 nm or less, when the mechanical load is applied to the silica particles (B), the silica particles (B) are less likely to be lost, and the attached resin particle main body (A) It is easy to improve strength and fluidity.
The volume average particle size of the silica particles (B) is more preferably from 100 nm to 350 nm, and further preferably from 100 nm to 250 nm.

  The volume average particle diameter of the silica particles (B) is obtained as a 50% diameter (D50v) in the cumulative frequency of the volume particle diameter measured by LS Coulter (Beckman-Coulter particle size measuring device).

[Ingredients, surface treatment]
Any of the silica mother particles and the silica child particles constituting the silica particles (B) may be silica, that is, particles containing SiO ₂ as a main component, and may be crystalline or amorphous. Moreover, the particle | grains manufactured from silicon compounds, such as water glass and alkoxysilane, may be sufficient, and the particle | grains obtained by grind | pulverizing quartz may be sufficient.
Further, from the viewpoint of dispersibility of the silica particles (B), the surface of the silica particles is preferably subjected to a hydrophobic treatment. For example, the silica particles are hydrophobized by coating the surface of the silica particles with alkyl groups. For this purpose, for example, a known organosilicon compound having an alkyl group may be allowed to act on silica particles. Details of the hydrophobizing method will be described later.

<Resin particle body (A)>
Next, the resin particle main body (A) to which the silica particles (B) are attached will be described.
The resin particle main body (A) is not particularly limited as long as the silica particles (B) described above can adhere to the surface, the particle size, and the material (component), and the use of the resin particles according to the present embodiment is not limited. And may be appropriately determined according to the relationship with the silica particles (B).

〔Particle size〕
The shape of the resin particle body (A) is not particularly limited, but the particle size is preferably 2 μm or more and 20 μm or less in terms of volume average particle size.
When the volume average particle diameter of the resin particle main body (A) is 2 μm or more, a decrease in fluidity can be suppressed. Further, when the volume average particle diameter of the resin particle main body (A) is 20 μm or less, the resin particle according to the present embodiment is used when the resin particle is used for powder coating, slush molding, or a recording material. The uniformity of the coating film or image formed by containing the resin particles according to the above is difficult to decrease.
The volume average particle size of the resin particle main body (A) is more preferably 3 μm or more and 15 μm or less.

  Here, the volume average particle diameter of the resin particle main body (A) is measured using Coulter Multisizer II (manufactured by Coulter), and the electrolyte is measured using ISOTON-II (manufactured by Coulter).

In the measurement, a measurement sample is added in a range of 0.5 mg to 50 mg in 2 ml of a 5% by weight aqueous solution of a surfactant such as sodium alkylbenzenesulfonate as a dispersant. This is added to 100 ml to 150 ml of electrolyte.
The electrolytic solution in which the sample is suspended is subjected to a dispersion process for 1 minute with an ultrasonic disperser, and a particle size distribution of particles in the range of 2 μm to 50 μm is measured using a 100 μm aperture with a Coulter Multisizer type II. . The number of particles to be sampled is 50,000.

For the particle size range (channel) divided on the basis of the particle size distribution measured in this way, the cumulative distribution is drawn from the small diameter side for the volume and number, respectively, and the cumulative particle size is 16% cumulative. D16v, cumulative number average particle diameter D16p, cumulative volume average particle diameter D50v, cumulative volume average particle diameter D50p, cumulative number average particle diameter D50p, cumulative volume average particle diameter D84v, cumulative number average particle diameter It is defined as D84p.
Here, the volume average particle diameter is obtained as a cumulative volume average particle diameter D50v.

[Material (component)]
The resin particle body (A) only needs to contain a resin. Hereinafter, the resin contained in the resin particle main body (A) is also referred to as “main body resin”.
As the main body resin, thermoplastic resins made of various natural or synthetic polymer substances can be used.
For example, polyolefin resins such as polyethylene and polypropylene, polystyrene resins such as polystyrene and acrylonitrile / butadiene / styrene copolymers (ABS resins), acrylic resins such as polymethyl methacrylate and polybutyl acrylate, rubbers such as polybutadiene and polyisoprene (Co) polymer, polyester resin such as polyethylene terephthalate, polybutylene terephthalate, vinyl chloride resin, vinyl aromatic resin, conjugated diene resin, polyamide resin, polyacetal resin, polycarbonate resin, thermoplastic polyurethane resin, fluorine resin, etc. alone Or it mixes and is used.

  Typically, an epoxy resin having a weight average molecular weight of 5,000 or more and 100,000 or less, a styrene-acrylic resin, a polyamide resin, a polyester resin, a polyvinyl resin, a polyolefin resin, a polyurethane resin, a polybutadiene resin, or the like is used alone or in combination. .

  When the resin particles according to this embodiment are applied to powder coating applications, polyester resin, epoxy resin, and acrylic resin are suitable as the main body resin.

  When the resin particles according to the present embodiment are applied to slush molding applications, the main body resin includes thermoplastic polyurethane resin, vinyl chloride resin, polyolefin resin, acrylate resin powder, vinyl aromatic resin, and conjugated diene resin. Is preferred.

  When the resin particles according to the present embodiment are applied to recording material (for example, toner) applications, polyester resin and acrylic resin are suitable as the main body resin.

  In addition to the main body resin, the resin particle main body (A) may further contain additives such as inorganic particles other than the silica particles (B), an ultraviolet absorber, and an antioxidant, depending on the intended use. .

[Silica particle (B) coverage (attachment amount)]
The amount of silica particles (B) attached to the surface of the resin particle main body (A) is the calculated coverage of the silica particles (B) relative to the surface area of the resin particle main body (A) (also referred to as “calculated coverage”). Is preferably in the range of 5% to 80%.
The calculated coverage is such that the specific gravity of the resin particle main body (A) is A [g / cm ³ ], the particle diameter of the resin particle main body (A) is R [μm], and the charged amount of the resin particle main body (A) is B [g ], When the specific gravity of the silica particles (B) is a [g / cm ³ ], the particle size of the silica particles (B) is r [nm], and the charged amount of the silica particles (B) is b [g], (√3 × A × b × R) / (0.001 × 2π × a × B × r) × 100].

When the calculated coverage is 5% or more, a decrease in fluidity of the resin particles according to the present embodiment is suppressed, and when it is 80% or less, various obstacles such as contamination due to separation of the silica particles (B) occur. Avoided.
The adhesion amount of the silica particles (B) is more preferably in a range where the calculated coverage is 30% or more and 70% or less.

<Application>
In the resin particles according to the present embodiment, the silica particles (B) having irregularly shaped silica particles are attached in a state in which they are difficult to be embedded in the surface of the resin particle main body (A) and are not easily released from the surface. For this reason, the resin particles according to the present embodiment are hardly sticky and hardly aggregate even when a mechanical load such as stirring is applied from the outside.
Since it has such characteristics, the resin particles according to the present embodiment can be applied to various uses such as toner, powder coating material, and recording material. Further, the present invention can be applied to so-called slush molding (also referred to as powder slush molding) in which resin particles are poured into a heated molding die and melt-molded. When applied to this application, since the resin particles according to the present embodiment have good aggregation resistance, the resin particles can easily spread inside the mold and can form a coating film that is less likely to be uneven in thickness.

<Method for producing resin particles>
In order to obtain the resin particles according to the present embodiment, it is first necessary to produce silica particles (B). The method for producing the silica particles (B) is not particularly limited as long as it is a method capable of producing silica particles in which the above-mentioned irregularly shaped silica child particles are adhered to the surface of the silica mother particles, so-called dry process. A method may be adopted, or a wet method may be adopted.
As a manufacturing method by a dry method, for example, silica particles having a particle size exceeding 500 nm are pulverized and classified to obtain two kinds of large and small silica particles (silica mother particles and silica child particles). A method of mechanically pressing and fixing the mother particles is exemplified.
As a manufacturing method by a wet method, for example, a silicon compound typified by alkoxysilane is used as a raw material, and two kinds of large and small silica particles are obtained by a sol-gel method, and silica child particles and silica mother particles are fused and integrated. There is a method of tying and fixing. As a wet method, besides the sol-gel method, there is a method of obtaining silica sol using water glass as a raw material.

  In order to produce the silica particles (B) having the various physical properties described above and further obtain the resin particles according to the present embodiment using the silica particles (B), the present embodiment has the following steps. It is desirable to employ a method for producing resin particles.

  The method for producing resin particles according to the present embodiment includes a step of preparing an alkali catalyst solution containing an alkali catalyst at a concentration of 0.8 mol / L or more and 1.0 mol / L or less in a solvent containing alcohol (hereinafter referred to as appropriate). , Referred to as a “preparation step”), and without adding the alkaline catalyst to the prepared alkaline catalyst solution, the tetrahydrochloric acid has a concentration of 0.7 mol / L to 1.8 mol / L. A step of supplying alkoxysilane to obtain silica particles (hereinafter referred to as “supply step” as appropriate) and a step of attaching the obtained silica particles to the surface of the resin particle body (hereinafter referred to as “attachment step” as appropriate). ").

According to the preparation step and the supply step in the method for producing resin particles according to this embodiment, tetraalkoxysilane as a raw material is supplied in the presence of an alcohol containing an alkali catalyst, but no additional alkali catalyst is supplied. In this method, the reaction system for producing silica particles is made short of an alkali catalyst.
Silica containing silica mother particles and silica child particles that adhere to the surface of the silica mother particles, have a particle size smaller than that of the silica mother particles, and have an average circularity of 0.7 to 0.85. Particles (B) are obtained. The reason for this is not clear, but is thought to be due to the following actions.

  First, an alkali catalyst solution containing an alkali catalyst is prepared in a solvent containing alcohol, and when tetraalkoxysilane is supplied into this solution, the tetraalkoxysilane supplied into the alkali catalyst solution reacts to produce core particles. Is generated. At this time, as long as the amount of the alkali catalyst in the reaction system is sufficient with respect to the amount of tetraalkoxysilane, the produced core particles grow by the reaction of tetraalkoxysilane, the silica particles become larger, and the silica It is thought that it becomes a silica mother particle in particle (B).

  In addition to the catalytic action, the alkali catalyst is coordinated to the surface of the generated core particle and contributes to the shape and dispersion stability of the core particle, but the alkali catalyst does not cover the surface of the core particle uniformly. (In other words, since the alkali catalyst is unevenly distributed and adheres to the surface of the core particle), it is considered that a partial bias occurs in the surface tension and chemical affinity of the core particle while maintaining the dispersion stability of the core particle. Therefore, irregularly shaped nuclear particles are easily generated.

In the supply step, when tetraalkoxysilane is supplied without supplying additional alkali catalyst, the amount of alkali catalyst gradually decreases with respect to the amount of tetraalkoxysilane, and finally there is not enough alkali catalyst to grow the core particles. When tetraalkoxysilane is supplied to the reaction system as much as possible, the growth of the core particles stops or becomes difficult to grow.
If tetraalkoxysilane is further supplied to this reaction system, it becomes an environment where silica particles smaller than the silica mother particles obtained by separately growing the core particles are easily formed.

  At this time, since the amount of the alkali catalyst present in the reaction system is not enough for the core particles of the silica mother particles to grow, it exists to the extent that silica particles smaller than the silica mother particles grow. The silica particles smaller than the silica mother particles are easily deformed for the same reason as that of the silica mother particle core particles, and the average circularity is 0.7 to 0.85. Particles are easily formed.

As a result, silica particles having an average circularity of 0.7 or more and 0.85 or less smaller than the silica mother particles formed in the reaction system become silica child particles.
In the reaction system, since the alkali catalyst is insufficient, the growth of the core particles of the silica child particles is limited, and the particle size of the silica child particles is smaller than the particle size of the silica mother particles.

  It is considered that the formed silica child particles are attracted to the surface of the silica mother particle by an interaction such as intermolecular force and adhere to the surface of the silica mother particle. While the alkali catalyst is insufficient, the silica particles adhering to the silica mother particles are fixed to the silica mother particles by tetraalkoxysilane additionally supplied into the reaction system. That is, it is considered that the tetraalkoxysilane fixes the silica mother particles and the silica child particles by covering and reacting with the gap between the silica mother particles and the silica child particles.

  At this time, if the supply amount of tetraalkoxysilane exceeds 1.8 mol / L, the silica particles are buried with tetraalkoxysilane and do not serve as the protruding portions of the silica particles. That is, the silica particles of the silica particles (B) may not bite into the resin particle body (A) or get caught.

  As mentioned above, according to the manufacturing method of the resin particle which concerns on this embodiment, it has adhered to the surface of a silica mother particle and this silica mother particle by passing through a preparatory process and a supply process, and a particle size is the said silica mother material. Silica particles (B) that are smaller than the particles and contain silica core particles having an average circularity of 0.7 or more and 0.85 or less are easily produced.

Further, according to the preparation step and the supply step, it is considered that the core particles and the silica child particles are generated by generating the nucleus particles having an irregular shape and growing the nucleus particles while maintaining the irregular shape. Thus, irregularly shaped silica particles (B) having high shape stability against mechanical load can be obtained.
Moreover, according to the preparation step and the supply step, it is considered that the generated irregular-shaped core particles are grown while maintaining the irregular shape, and the silica particles (B) are obtained. Silica particles that are hard to break are obtained.
In particular, the silica mother particles and the silica child particles are fixed by the tetraalkoxysilane in the supplying step covering the gap between the silica mother particles and the silica child particles and reacting with the tetraalkoxysilane. Silica particles (B) that have a stronger bond than conventional methods of sintering and adhere, and that silica particles (B) are not easily detached from silica mother particles even when subjected to a mechanical load (B). ).

Furthermore, according to the preparation step and the supply step, since the tetraalkoxysilane and the alkali catalyst are respectively supplied in the alkali catalyst solution and the reaction of the tetraalkoxysilane is caused to generate particles, Compared to the case of producing irregularly shaped silica particles by the conventional sol-gel method, the total amount of alkali catalyst used is reduced, and as a result, the step of removing the alkali catalyst can be omitted. This is particularly advantageous when the silica particles (B) are applied to products that require high purity.
Hereinafter, each process of the manufacturing method of the resin particle which concerns on this embodiment is demonstrated in detail.

The method for producing resin particles according to the present embodiment is mainly divided into three steps. One is a step of preparing an alkali catalyst solution (preparation step), and the other is a step of supplying silica particles by supplying tetraalkoxysilane without supplying an alkali catalyst to the alkali catalyst solution. The silica particles (B) are produced by these two steps. Then, the process (attachment process) which makes the obtained silica particle (B) adhere to a resin particle main body (A) is performed.
In addition, you may perform the hydrophobization process by a hydrophobization process process with respect to the silica particle (B) obtained by passing through the said supply process, before using for the said adhesion process.

[Preparation process]
In the preparation step, a solvent containing alcohol is prepared, an alkali catalyst is added thereto, and an alkali catalyst solution is prepared.

The solvent containing alcohol may be a solvent of alcohol alone or, if necessary, ketones such as water, acetone, methyl ethyl ketone, methyl isobutyl ketone, cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, It may be a mixed solvent with other solvents such as ethers such as dioxane and tetrahydrofuran. In the case of a mixed solvent, the amount of alcohol relative to the other solvent is preferably 80% by mass or more (desirably 90% by mass or more).
Examples of the alcohol include lower alcohols such as methanol and ethanol.

  On the other hand, the alkali catalyst is a catalyst for accelerating the reaction (hydrolysis reaction, condensation reaction) of tetraalkoxysilane, and examples thereof include basic catalysts such as ammonia, urea, monoamine, quaternary ammonium salts, Ammonia is particularly desirable.

The concentration (content) of the alkali catalyst is preferably 0.8 mol / L or more and 1.0 mol / L, more preferably 0.82 mol / L or more and 0.95 mol / L, more preferably 0.82 mol / L. / L or more and 0.90 mol / L are more preferable.
When the concentration of the alkali catalyst is 0.80 mol / L or more, when tetraalkoxysilane is supplied in the particle generation step, the dispersibility of the core particles in the growth process of the generated core particles becomes stable, and secondary aggregates It is possible to suppress the formation of a coarse aggregate such as a gel and a gelled state.
On the other hand, when the concentration of the alkali catalyst is higher than 1.0 mol / L, the stability of the generated core particles becomes excessive, and spherical core particles are generated, and irregular cores having an average circularity of 0.85 or less. Particles cannot be obtained, and as a result, irregularly shaped silica particles cannot be obtained.
In addition, the density | concentration of an alkali catalyst is a density | concentration with respect to an alcohol catalyst solution (an alkali catalyst + solvent containing alcohol).

[Supply process]
Next, a supply process is demonstrated.
In the supply step, tetraalkoxysilane is supplied to a concentration of 0.7 mol / L or more and 1.8 mol / L or less in the alkali catalyst solution without additional supply of an alkali catalyst to generate silica particles. It is a process. In the method for producing resin particles according to the present embodiment, while promoting particle growth in this way, the alkali catalyst is brought into a deficient state, thereby forming silica mother particles and silica child particles, and fixing them together. And silica particles (B) are formed.

Here, “the concentration of 0.7 mol / L or more and 1.8 mol / L or less” represents the concentration in the reaction system of the total supply amount for supplying tetraalkoxysilane in the supply step. That is, when the supply of tetraalkoxysilane is completed in the supply step, the concentration of tetraalkoxysilane contained in the alkali catalyst solution prepared in the preparation step is 0.7 mol / L or more and 1.8 mol / L or less. Good.
When the concentration of tetraalkoxysilane is less than 0.7 mol / L, silica core particles are not generated, or even if generated, silica core particles having an average circularity in the range of 0.7 to 0.85 are formed. I can't.
Further, when the concentration of tetraalkoxysilane exceeds 1.8 mol / L, the silica particles adhering to the silica mother particles are buried with tetraalkoxysilane, and the resulting silica particles (B) are the resin particle main body (A). It becomes easy to move the surface of the.

  The concentration of tetraalkoxysilane supplied in the supplying step is preferably 0.7 mol / L or more and 1.8 mol / L or less, and more preferably 0.9 mol / L or more and 1.7 mol / L or less.

The supply speed of the tetraalkoxysilane supplied in the supply process is not particularly limited, but is preferably within the following range from the viewpoint of producing the silica particles (B) having the shape described above.
That is, the tetraalkoxysilane supply rate is preferably 0.001 mol / (mol · min) or more and 0.010 mol / (mol · min) or less with respect to the alcohol in the alkali catalyst solution.
This means that tetraalkoxysilane is supplied at a supply rate of 0.001 mol or more and 0.010 mol or less per minute with respect to 1 mol of alcohol used in the step of preparing the alkali catalyst solution.
By setting the supply rate of the tetraalkoxysilane within the above range, irregularly shaped silica child particles and irregularly shaped silica mother particles are easily generated at a high rate (for example, 95% by number or more).
When the tetraalkoxysilane supply rate is less than 0.001 mol / (mol · min), the tetraalkoxysilane can be supplied to the core particles without any deviation before the reaction between the core particles and the tetraalkoxysilane. It is considered that there is no uneven shape and spherical silica particles are generated.
When the supply rate of tetraalkoxysilane is larger than 0.010 mol / (mol · min), the supply amount for the reaction between tetraalkoxysilanes at the stage of forming the core particles or for the reaction between the tetraalkoxysilane and the core particles in the particle growth. Becomes excessive and gelation occurs in the reaction system, which inhibits the formation of nuclear particles and the growth of particles.

  The supply rate of tetraalkoxysilane in the supplying step is preferably 0.0020 mol / (mol · min) or more and 0.0065 mol / (mol · min) or less, and is 0.0022 mol / (mol · min) or more and 0.0060 mol / (mol). -Min) or less is more preferable.

In the supplying step, as the tetraalkoxysilane supplied into the alkali catalyst solution, for example, a silane compound such as a tetrafunctional silane compound may be used.
Specifically, for example, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane and the like can be mentioned. From the viewpoint of controllability of the reaction rate and the shape, particle size, particle size distribution, etc. of the obtained silica particles. Tetramethoxysilane and tetraethoxysilane are preferable.

  Through the above two steps, silica particles (B) are obtained. In this state, the obtained silica particles (B) can be obtained in the form of a dispersion, but they may be used as they are as a silica particle dispersion, or removed as a powder of silica particles (B) after removing the solvent. It may be used.

  When used as a silica particle dispersion, the solid content concentration of the silica particles (B) may be adjusted by diluting or concentrating with water or alcohol as necessary. In addition, the silica particle dispersion may be used after solvent substitution with other water-soluble organic solvents such as alcohols, esters, and ketones.

On the other hand, when used as a powder of silica particles, it is necessary to remove the solvent from the silica particle dispersion. As this solvent removal method, 1) the solvent is removed by filtration, centrifugation, distillation, etc. Known methods such as a method of drying with a dryer, a shelf dryer, etc., 2) a method of directly drying the slurry with a fluidized bed dryer, a spray dryer or the like can be used. The drying temperature is not particularly limited, but is desirably 200 ° C. or lower. When the temperature is higher than 200 ° C., bonding between primary particles and generation of coarse particles are likely to occur due to condensation of silanol groups remaining on the surface of the silica particles.
The dried silica particles are preferably crushed and sieved as necessary to remove coarse particles and aggregates. The crushing method is not particularly limited, and for example, the crushing method is performed by a dry pulverization apparatus such as a jet mill, a vibration mill, a ball mill, or a pin mill. The sieving method is performed by a known method such as a vibration sieve or a wind sieving machine.

[Hydrophobicization treatment process]
The silica particles (B) obtained as described above may be subjected to a hydrophobic treatment on the surface with a hydrophobic treatment agent.
Here, examples of the hydrophobizing agent include known organosilicon compounds having an alkyl group (for example, methyl group, ethyl group, propyl group, butyl group, etc.). Specific examples include, for example, silazane compounds. (For example, silane compounds such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylchlorosilane, and trimethylmethoxysilane, hexamethyldisilazane, tetramethyldisilazane, and the like). One type of hydrophobic treatment agent may be used, or a plurality of types may be used.
Among these hydrophobizing agents, organosilicon compounds having a trimethyl group such as trimethylmethoxysilane and hexamethyldisilazane are suitable.

  The amount of the hydrophobizing agent used is not particularly limited, but in order to obtain the effect of hydrophobizing, for example, 1% by mass or more and 100% by mass or less, preferably 5% by mass or more with respect to the silica particles (B). 80% by mass or less.

  As a method for obtaining a hydrophobized silica particle dispersion that has been hydrophobized with a hydrophobizing agent, for example, a required amount of a hydrophobizing agent is added to the silica particle dispersion, and 30 to 80 ° C. with stirring. A method of subjecting the silica particles (B) to a hydrophobization treatment to obtain a hydrophobized silica particle dispersion by reacting in the above temperature range. When the reaction temperature is lower than 30 ° C., the hydrophobization reaction hardly proceeds, and when the reaction temperature exceeds 80 ° C., the gelation of the dispersion due to the self-condensation of the hydrophobizing agent or the aggregation of silica particles tends to occur. is there.

On the other hand, as a method of obtaining powdered hydrophobic silica particles, a method of obtaining a hydrophobized silica particle dispersion by the above method and then drying by the above method to obtain a powder of hydrophobized silica particles, a silica particle dispersion After obtaining a powder of hydrophilic silica particles, a method of obtaining a powder of hydrophobic silica particles by adding a hydrophobizing agent and applying a hydrophobic treatment, a hydrophobized silica particle dispersion was obtained. Thereafter, after drying to obtain a powder of hydrophobized silica particles, a method for obtaining a powder of hydrophobized silica particles by adding a hydrophobizing agent and performing hydrophobizing treatment, and the like can be mentioned.
Here, as a method of hydrophobizing the silica particles (B) of the powder, the hydrophilic silica particles of the powder are stirred in a treatment tank such as a Henschel mixer or a fluidized bed, and a hydrophobizing agent is added thereto. There is a method in which the inside of the treatment tank is heated to gasify the hydrophobizing agent and react with the silanol groups on the surface of the powdered silica particles (B). Although processing temperature is not specifically limited, For example, 80 degreeC or more and 300 degrees C or less are good, Desirably 120 degreeC or more and 200 degrees C or less.

-Average shrinkage-
The silica particles (B) obtained through the preparation step and the supply step as described above also have a feature that the average shrinkage is 8 or more and 30 or less.
Here, the average shrinkage is measured by observing primary particles of silica particles (B) after dispersing silica particles in resin particles (polyester, weight average molecular weight Mw = 50000) having a volume average particle size of 100 μm using a SEM apparatus. From the planar image analysis of the obtained primary particles, it is calculated using the following formula (3).
Silica particle shrinkage = (1−H / I) × 100 (3)
[In Formula (3), H represents the envelope circumference of the silica particles (B) on the image, and I represents the circumference of the silica particles on the image. ]
The envelope circumference length means the circumference length when the apexes of the convex portions of the silica particles (B) in the planar image are connected with the shortest distance, and the circumference length of the silica particles (B) in the planar image. It means the length of the contour itself.
The average shrinkage of the silica particles (B) is calculated as the average of the shrinkage of each silica particle calculated from the formula (3) for 100 silica particles.

When the average shrinkage of the silica particles (B) is 8 or more, adhesion to the resin particle main body (A) is easily maintained, and when the average shrinkage is 30 or less, the resin particle main body (A) is easily bited.
The average shrinkage of the silica particles (B) is more preferably 10 or more and 20 or less.

[Adhesion process]
Subsequently, in the attaching step, the silica particles (B) obtained by the above-described method are attached to the surface of the resin particle main body (A).
As a method for attaching the silica particles (B) to the surface of the resin particle main body (A), for example, the silica particles (B), the resin particle main body (A), and a component to be attached if necessary are V Examples thereof include a method of adding to a mold blender, a Henschel mixer, a Redige mixer, and the like and stirring, and the silica particles (B) may be attached to the surface of the resin particle main body (A) in stages.

As described above, the resin particles according to this embodiment preferably have the silica particles (B) attached to the surface of the resin particle main body (A) in a range where the calculated coverage is 5% or more and 80%.
In order to make the adhesion amount of the silica particles (B) within the above range, in a V-type blender, a Henschel mixer, a Redige mixer, etc., 0.1% by mass or more and 10% by mass with respect to the total mass of the resin particle main body (A). What is necessary is just to add the silica particle (B) of the mass% or less.

-Production of resin particle body (A)-
The production method of the resin particle main body (A) is not particularly limited. For example, a method in which the main body resin is hot melt kneaded and then pulverized and classified (kneading pulverization method), an oil in which the main body resin is dissolved in a water-soluble organic solvent. After the phase is suspended and dispersed in an aqueous phase containing a dispersant, the solvent is removed (dissolution suspension method), and the main resin obtained from the main resin monomer by emulsion polymerization or the like is agglomerated to form particles It can be obtained by a method (emulsion polymerization aggregation method) or the like.
When the resin particle main body (A) contains other components such as inorganic particles, the main resin and other components may be mixed in advance. When the emulsion polymerization aggregation method is adopted, the main body resin monomer and other components may be mixed and subjected to emulsion polymerization.

Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention. Further, “parts” and “%” are based on mass unless otherwise specified.
Incidentally, the molecular weight of each component used in the following, methanol: _32.04, NH 3: _17.03, tetramethoxysilane (TMOS): was 152.22. The specific gravity of methanol was 0.79, and the specific gravity of 10% ammonia water was 1.00.

[Example 1]
-Preparation process-
A 1 L glass reaction vessel equipped with a metal stirring bar, a dropping nozzle (a micro tube pump made of Teflon (registered trademark)) and a thermometer was prepared as an experimental apparatus.
Into the reaction vessel of this experimental apparatus, 62.37 parts of methanol and 13.94 parts of 10% aqueous ammonia as an initial charge amount were added and stirred to obtain an alkali catalyst solution. The amount of ammonia catalyst in the alkaline catalyst solution at this time, that is, NH ₃ (mol) / [NH ₃ + methanol + water (L)] was 0.90 mol / L.

-Supplying process (production of silica particles 1)-
Thereafter, the reaction vessel temperature was set to 20 ° C., the inside of the reaction vessel was replaced with nitrogen gas, and while stirring, the flow rate of tetramethoxysilane (TMOS) was set to 1 part / min to start dropping, and the reaction was performed for 15 minutes. A suspension of silica particles (silica particles 1) was obtained. At this time, the total supply amount of tetramethoxysilane was 15 parts, and the total supply amount of tetramethoxysilane was 1.07 mol / L with respect to the alkali catalyst solution.
In this supply step, the supply rate of tetramethoxysilane was 0.00337 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.
When the silica particles 1 in the obtained suspension slurry were measured with the particle size measuring instrument described above, the volume average particle size was 240 nm and the particle size distribution index was 1.18.

-Hydrophobic treatment process (Preparation of hydrophobized silica particles 1)-
Thereafter, trimethylsilane was added to the obtained suspension, and heated and dried on a 100 ° C. hot plate to obtain powder particles (hydrophobized silica particles 1).
The obtained hydrophobized silica particles 1 were added to resin particles having a particle diameter of 100 μm as described above, and SEM observation was performed. Thereafter, as a result of image analysis of the SEM photograph as described above, the average circularity of the hydrophobized silica particles 1 is 0.67, the average circularity of the silica child particles is 0.81, and the average shrinkage The rate was 11.32.
Further, the particle diameters of the silica mother particles and the silica child particles constituting the hydrophobized silica particles 1 were also measured by SEM as described above. As a result, the particle diameter of the silica mother particles was 161 nm. The particle size was 45 nm.

-Manufacture of resin particle body (Manufacture of amorphous resin particles A)-
In a reaction vessel equipped with a stirrer, thermometer, condenser and nitrogen gas inlet tube, dimethyl terephthalate 23 mol%, isophthalic acid 10 mol%, dodecenyl succinic anhydride 15 mol%, trimellitic anhydride 3 mol%, bisphenol A ethylene oxide 2 mol adduct 5 mol% and bisphenol A propylene oxide 2 mol adduct 45 mol% were charged and the reaction vessel was purged with dry nitrogen gas, and then added as a catalyst at a rate of 0.06 mol% dibutyltin oxide and nitrogen gas. The mixture was allowed to stir at about 190 ° C. for about 7 hours under a stream of air, and the temperature was further raised to about 250 ° C. for about 5.0 hours. After that, the reaction vessel was depressurized to 10.0 mmHg and about 0.0. The mixture was stirred for 5 hours to obtain a polyester resin (1) having a polar group in the molecule.
Next, 100 parts by mass of the polyester resin (1) was melt-kneaded with a Banbury mixer type kneader. The kneaded product is formed into a plate shape with a thickness of about 1 cm with a rolling roll, coarsely pulverized to about several millimeters with a Fitzmill type pulverizer, finely pulverized with an IDS type pulverizer, and then classified with an elbow type classifier. Sequentially, amorphous resin particles A having a volume average particle diameter of 7 μm were obtained.

-Adhesion process-
Hydrophobized silica particles 1 are added to 20 parts of irregular shaped resin particles A having a volume average particle size of 7 μm obtained by the above production method so that the coverage is 50%, and then at 0.45 sample mill at 15000 rpm for 30 seconds. By mixing, resin particles containing hydrophobized silica particles (1) were obtained. At this time, the specific gravity of the amorphous resin particles A as the resin particle body was 1.05, and the specific gravity of the hydrophobized silica particles 1 as the silica particles was 1.5.

[Resin particle evaluation]
About the obtained hydrophobized silica particle-containing resin particles (1): 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The flowability and anti-aggregation property were evaluated by the following methods. The results are shown in Table 2.

(1. Evaluation of dispersibility and maintenance of silica particles on the surface of the resin particle body)
-Evaluation of dispersibility-
About the hydrophobized silica particle containing resin particle (1) after manufacture, the surface was observed by SEM observation. Furthermore, the adhesion area of the hydrophobized silica particles is measured by image analysis, and the ratio of the total adhesion area D of the specific silica particles to the surface area C of the resin particle body [(D / C) × 100] And was evaluated based on the following evaluation criteria.
-Evaluation criteria (dispersibility)-
○: Silica particles adhere to the surface of the resin particle main body without being unevenly distributed at a coverage of 45% or more, and almost no aggregates are observed.
Δ: Although some silica particle aggregates are observed, the silica particles have a coverage of 40% or more and less than 45% and are not unevenly distributed on the surface of the resin particle body. ×: Silica particle aggregates are scattered. In addition, the silica particle coverage of the resin particle main body surface is less than 40%, which is poor dispersion.

-Evaluation of dispersion sustainability-
After applying a mechanical load to the hydrophobized silica particle-containing resin particles (1), the dispersibility of the hydrophobized silica particles, that is, the dispersion maintaining property was evaluated. Specifically, the evaluation was performed as follows.
5 g of the hydrophobized silica particle-containing resin particles (1) and 200 g of 100 μm iron powder were put in a glass bottle and mixed for 60 minutes by a tumbler shaker. Then, the surface of the resin particle was observed by SEM observation. Furthermore, the adhesion area of the hydrophobized silica particles was measured by image analysis, the coverage of the hydrophobized silica particles was calculated, and evaluated based on the following evaluation criteria.

-Evaluation criteria (dispersion maintenance)-
◯: Slight movement of the silica particles to the surface recesses of the resin particle main body is observed, but the silica particle coverage of the resin particle main body surface is 40% or more.
Δ: Although movement of silica particles is observed in the recesses on the surface of the resin particle body, the coverage of the silica particles on the surface of the resin particle body is 30% or more and less than 40%.
X: Many movements of the silica particles are observed in the recesses on the surface of the resin particle body, and the silica particle coverage on the surface of the resin particle body is less than 30%.

(2. Evaluation of fluidity)
For the hydrophobized silica particle-containing resin particles (1), the loose apparent specific gravity and the solid apparent specific gravity of the resin particles are measured using a powder tester manufactured by Hosokawa Micron Co., Ltd. The following formula is used to determine the loose apparent specific gravity and the solid apparent specific gravity. The compression ratio was determined from the ratio, and the fluidity of the resin particles was evaluated from the calculated compression ratio.
Compression ratio = [(Fixed apparent specific gravity) − (Loose apparent specific gravity)] / Folded apparent specific gravity

The “slack apparent specific gravity” is a measurement value derived by filling resin particles into a sample cup with a capacity of 100 cm ³ and weighing them, and filling the resin cup in a state where the resin particles are naturally dropped into the sample cup. Specific gravity. “Fixed apparent specific gravity” refers to the apparent specific gravity in which degassing is performed by tapping from the state of loose apparent specific gravity, and resin particles are rearranged and packed more densely.
In addition, in the fluidity evaluation, similarly to the evaluation of the dispersion maintaining property, the mechanical load is given by mixing for 60 minutes with a tumbler shaker before the measurement.

-Evaluation criteria (liquidity)-
○: Compression ratio is less than 0.3 Δ: Compression ratio is 0.3 or more and less than 0.4 ×: Compression ratio is 0.4 or more

(3. Evaluation of cohesiveness)
5 g of the hydrophobized silica particle-containing resin particles (1) and 200 g of 100 μm iron powder were placed in a glass bottle and mixed for 30 minutes by shaking a Turbula, and then the iron powder was removed with a sieve having a pore size of 75 μm. Thereafter, 2 g of the hydrophobized silica particle-containing resin particles (1) under the sieve is placed on a 45 μm sieve, vibrated for 90 seconds with an amplitude of 1 mm, and the appearance of the hydrophobized silica particle-containing resin particles (1) is observed. Evaluation was performed based on the following evaluation criteria.
Aggregation degree (%) = mass on net of 45 μm (g) ÷ 2 × 100

-Evaluation criteria (cohesiveness)-
○: Aggregation degree is less than 10% Δ: Aggregation degree is 10% or more and less than 30% ×: Aggregation degree is 30% or more

[Example 2]
In the supply step of Example 1, a suspension of silica particles (silica particles 2) was obtained in the same manner as in Example 1 except that the amount of tetramethoxysilane dropped was 25 parts.
The volume average particle size of silica particles 2 in this suspension slurry was 389 nm, and the particle size distribution index was 1.22.
The total supply amount of tetramethoxysilane in the supply step was 1.78 mol / L with respect to the alkaline catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00561 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 2.
The hydrophobic silica particles 2 were subjected to image analysis in the same manner as in Example 1. As a result, the average circularity was 0.68, the average circularity of the silica child particles was 0.77, and the average shrinkage was 28.70.
Further, the particle diameters of the silica mother particles and silica child particles constituting the hydrophobized silica particles 2 were also measured by SEM as described above. As a result, the particle diameter of the silica mother particles was 172 nm. The particle size was 103 nm.

The adhering step was performed in the same manner as in Example 1 except that the thus obtained hydrophobic silica particles 2 were used in place of the hydrophobic silica particles 1.
This obtained the hydrophobized silica particle containing resin particle (2).
About the obtained hydrophobized silica particle-containing resin particles (2), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

Example 3
In the supply step of Example 1, a suspension of silica particles (silica particles 3) was obtained in the same manner as in Example 1, except that the amount of tetramethoxysilane added was 10 parts.
The volume average particle diameter of silica particles 3 in this suspension slurry was 117 nm, and the particle size distribution index was 1.15.
In addition, the tetramethoxysilane total supply amount in the supply step was 0.71 mol / L with respect to the alkali catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00225 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 3.
The hydrophobic silica particles 3 were subjected to image analysis in the same manner as in Example 1. As a result, the average circularity was 0.68, the average circularity of the silica child particles was 0.83, and the average shrinkage ratio was 9.20.
Further, the particle diameters of the silica mother particles and silica child particles constituting the hydrophobized silica particles 3 were also measured by SEM as described above. As a result, the particle diameter of the silica mother particles was 98 nm. The particle size was 14 nm.

The adhering step was performed in the same manner as in Example 1 except that the hydrophobized silica particles 3 thus obtained were used instead of the hydrophobized silica particles 1.
Thereby, hydrophobized silica particle-containing resin particles (3) were obtained.
About the obtained hydrophobized silica particle-containing resin particles (3), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

Example 4
In the preparation step of Example 1, a suspension of silica particles (silica particles 4) was prepared in the same manner as in Example 1 except that an alkali catalyst solution was prepared by changing 15.5 parts of 10% aqueous ammonia initially charged. Obtained.
At this time, the amount of ammonia catalyst in the alkaline catalyst solution, that is, NH ₃ (mol) / [NH ₃ + methanol + water (L)] was 0.99 mol / L.
Moreover, the volume average particle diameter of the silica particles 4 in the obtained suspension slurry was 185 nm, and the particle size distribution index was 1.13.
In addition, the tetramethoxysilane total supply amount in the supply step was 1.05 mol / L with respect to the alkali catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00337 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 4.
The hydrophobic silica particles 4 were subjected to image analysis in the same manner as in Example 1. As a result, the average circularity was 0.74, the average circularity of the silica child particles was 0.85, and the average shrinkage was It was 8.30.
Further, the particle diameters of the silica mother particles and the silica child particles constituting the hydrophobized silica particles 4 were also measured by SEM as described above. As a result, the particle diameter of the silica mother particles was 155 nm. The particle size was 18 nm.

The adhering step was performed in the same manner as in Example 1 except that the hydrophobized silica particles 4 thus obtained were used in place of the hydrophobized silica particles 1.
Thereby, hydrophobic silica particle-containing resin particles (4) were obtained.
About the obtained hydrophobized silica particle-containing resin particles (4), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

Example 5
In the preparation step of Example 1, a suspension of silica particles (silica particles 5) was prepared in the same manner as in Example 1 except that an alkaline catalyst solution was prepared by adding 12.5 parts of 10% ammonia water initially charged. Obtained.
The amount of ammonia catalyst in the alkaline catalyst solution at this time, that is, NH ₃ (mol) / [NH ₃ + methanol + water (L)] was 0.82 mol / L.
Moreover, the volume average particle diameter of the silica particles 4 in the obtained suspension slurry was 356 nm, and the particle size distribution index was 1.29.
In addition, the tetramethoxysilane total supply amount in the supply step was 1.09 mol / L with respect to the alkaline catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00337 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 5.
The hydrophobic silica particles 5 were subjected to image analysis in the same manner as in Example 1. As a result, the average circularity was 0.56, the average circularity of the silica child particles was 0.71, and the average shrinkage was It was found to be 19.50.
Further, the particle diameters of the silica mother particles and the silica child particles constituting the hydrophobized silica particles 5 were also measured by SEM as described above. As a result, the particle diameter of the silica mother particles was 196 nm. The particle size was 84 nm.

The adhering step was performed in the same manner as in Example 1 except that the thus obtained hydrophobized silica particles 5 were used in place of the hydrophobized silica particles 1.
Thereby, hydrophobized silica particle-containing resin particles (5) were obtained.
About the obtained hydrophobized silica particle-containing resin particles (5), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

Example 6
In the production of the resin particle main body A of Example 1, classification was sequentially performed with an elbow type classifier to obtain amorphous resin particles B having a volume average particle diameter of 2 μm.
A silica particle-containing resin particle (6) was produced in the same manner as in Example 1 except that this irregular resin particle B was used. At this time, the hydrophobized silica particles 1 were used so that the calculated coverage with respect to the amorphous resin particles B was 50%.
About the obtained hydrophobized silica particle-containing resin particles (6), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

Example 7
In the production of the resin particle main body A of Example 1, classification was sequentially performed with an elbow type classifier to obtain amorphous resin particles C having a volume average particle diameter of 20 μm.
A silica particle-containing resin particle (7) was produced in the same manner as in Example 1 except that this irregular resin particle C was used. At this time, the hydrophobized silica particles 1 were used so that the calculated coverage with respect to the amorphous resin particles C was 50%.
About the obtained hydrophobic silica particle-containing resin particles (7), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

Example 8
Using the polyester resin (1) obtained in the production of the resin particle main body A of Example 1, 95 parts of this polyester resin (1) and 5 parts of Carnauba wax (manufactured by Toa Kasei Co., Ltd.) were mixed with a Banbury mixer type kneader. Was melt kneaded. The kneaded product is formed into a plate shape with a thickness of about 1 cm with a rolling roll, coarsely pulverized to about several millimeters with a Fitzmill type pulverizer, finely pulverized with an IDS type pulverizer, and then classified with an elbow type classifier. Sequentially, amorphous resin particles D having a volume average particle diameter of 7 μm were obtained.
A silica particle-containing resin particle (8) was produced in the same manner as in Example 1 except that this irregular resin particle D was used. At this time, the hydrophobized silica particles 1 were used so that the calculated coverage with respect to the amorphous resin particles D was 50%.
About the obtained hydrophobic silica particle-containing resin particles (8), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

[Comparative Example 1]
In the preparation step of Example 1, a suspension of silica particles (silica particles 101) was prepared in the same manner as in Example 1 except that an alkali catalyst solution was prepared by changing the initial charge of 10% aqueous ammonia to 16.50 parts. Obtained.
At this time, the amount of ammonia catalyst in the alkaline catalyst solution, that is, NH ₃ (mol) / [NH ₃ + methanol + water (L)] was 1.04 mol / L.
Moreover, the volume average particle diameter of the silica particles 101 in the obtained suspension slurry was 170 nm, and the particle size distribution index was 1.12.
In addition, the total supply amount of tetramethoxyxysilane in the supply step was 1.04 mol / L with respect to the alkaline catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00337 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 101.
The hydrophobic silica particles 101 were subjected to image analysis in the same manner as in Example 1. As a result, the average circularity was 0.80, the average circularity of the silica child particles was 0.92, and the average shrinkage was It was found to be 4.50.
Further, the particle diameters of the silica mother particles and the silica child particles constituting the hydrophobized silica particles 101 were also observed by SEM as described above. As a result, the shape of the silica particles was spherical (172 nm), and the child particles Was not attached.

The attachment step was performed in the same manner as in Example 1 except that the thus obtained hydrophobic silica particles 101 were used in place of the hydrophobic silica particles 1.
Thereby, hydrophobic silica particle-containing resin particles (R1) were obtained.
About the obtained hydrophobized silica particle-containing resin particles (R1), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

[Comparative Example 2]
In the preparation step of Example 1, a suspension of silica particles (silica particles 102) was prepared in the same manner as in Example 1 except that an alkaline catalyst solution was prepared by changing 11.00 parts of 10% ammonia water initially charged. Obtained.
The amount of ammonia catalyst in the alkaline catalyst solution at this time, that is, NH ₃ (mol) / [NH ₃ + methanol + water (L)] was 0.73 mol / L.
Further, the volume average particle diameter of silica particles 102 in the obtained suspension slurry was 108 nm, and the particle size distribution index was 1.10.
In addition, the tetramethoxysilane total supply amount in the supply step was 1.11 mol / L with respect to the alkaline catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00337 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 102.
The hydrophobic silica particles 102 were subjected to image analysis in the same manner as in Example 1. As a result, the average circularity was 0.91, the average circularity of the silica child particles was 0.93, and the average shrinkage was It was 0.76.
Further, the particle diameters of the silica mother particles and silica child particles constituting the hydrophobized silica particles 5 were also measured by SEM as described above. As a result, fine powder was generated, but the particles were adhered to the mother particles. No konpeito-type particles were produced.

The adhering step was performed in the same manner as in Example 1 except that the thus obtained hydrophobized silica particles 102 were used in place of the hydrophobized silica particles 1.
Thereby, hydrophobized silica particle-containing resin particles (R2) were obtained.
About the obtained hydrophobized silica particle-containing resin particles (R2), as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

[Comparative Example 3]
In the supply process of Example 1, when the dropping amount of tetramethoxysilane was 30 parts, the suspension gelled and particles were not obtained.
At this time, the total supply amount of tetramethoxyxysilane was 2.14 mol / L with respect to the alkali catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00675 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

[Comparative Example 4]
In the supply step of Example 1, a suspension of silica particles (silica particles 104) was obtained in the same manner as in Example 1 except that the amount of tetramethoxysilane added was 8 parts.
The volume average particle size of silica particles 104 in this suspension slurry was 110 nm, and the particle size distribution index was 1.13.
In addition, the tetramethoxysilane total supply amount in the supply step was 0.57 mol / L with respect to the alkali catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00179 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 104.
The hydrophobic silica particles 104 were subjected to image analysis in the same manner as in Example 1. As a result, there was no particle corresponding to the silica child particles, and the average circularity was 0.92. A fine powder of 91 was mixed. The average shrinkage of the hydrophobized silica particles 104 was 0.75.

The adhering step was performed in the same manner as in Example 1 except that the hydrophobized silica particles 104 thus obtained were used instead of the hydrophobized silica particles 1.
Thereby, hydrophobized silica particle-containing resin particles (R4) were obtained.
About the obtained hydrophobized silica particle-containing resin particles (R4), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

[Comparative Example 5]
In the supply step of Example 1, silica particles (silica particles) were prepared in the same manner as in Example 1 except that 10% ammonia water was supplied at a rate of 0.13 parts / min for 15 minutes simultaneously with the dropwise addition of tetramethoxysilane. 104) was obtained.
The volume average particle size of silica particles 105 in this suspension slurry was 260 nm, and the particle size distribution index was 1.10.
In addition, the total supply amount of tetramethoxyxysilane in the supply step was 1.07 mol / L with respect to the alkaline catalyst solution.
In this supply step, the supply rate of tetraalkoxysilane was 0.00337 mol / (mol · min) with respect to the alcohol (methanol) in the alkali catalyst solution.

Subsequently, a hydrophobizing treatment step was performed in the same manner as in Example 1 to obtain hydrophobized silica particles 105.
The hydrophobic silica particles 105 were subjected to image analysis in the same manner as in Example 1. As a result, there was no particle corresponding to the silica child particles, the sphere having an average circularity of 0.98, and the average circularity of 0. A fine powder of 91 was mixed. It was also found that the average shrinkage of the hydrophobized silica particles 105 was 0.02.

The adhering step was performed in the same manner as in Example 1 except that the thus obtained hydrophobized silica particles 105 were used in place of the hydrophobized silica particles 1.
Thereby, hydrophobized silica particle-containing resin particles (R5) were obtained.
About the obtained hydrophobic silica particle-containing resin particles (R5), in the same manner as in Example 1, 1. Dispersibility and maintainability of silica particles on the surface of the resin particle body; The fluidity and the aggregation resistance were evaluated. The results are shown in Table 2.

As can be seen from Table 2, the hydrophobized silica particle-containing resin particles of the examples were excellent in all of dispersibility, dispersion maintenance, fluidity, and agglomeration.
In particular, in Example 2, since the particle size distribution of the silica particles is wide and the number of silica child particles adhering to the silica mother particles is large, the spike effect when coated on the resin particle body is high. Compared to the examples, it is considered that the dispersibility, the dispersion maintaining property, and the fluidity are excellent.
Moreover, in Example 5, since the shape of the silica particle is more irregular (because of the low degree of circularity), when the resin particle main body is coated with the silica particle containing this, the uneven distribution in the recesses or the like hardly occurs It is considered that the dispersibility and the dispersion maintaining property are superior to those of the examples.
On the other hand, the resin particles containing the silica particles described in Comparative Examples 1, 2, 4, and 5 obtain the same results as the Examples with respect to all of the dispersibility, dispersion maintaining property, fluidity, and aggregation property. I couldn't. This is probably because the silica particles (B) according to the present embodiment are not used, and thus the spike effect and the spacer effect as described above are not expressed or are hardly expressed.

  As described above, in Comparative Example 3, the silica particles were not obtained because the dispersion was gelated in the process of producing the silica particles. Therefore, in Table 2, each column of “shape and characteristics of silica particles” and “evaluation result” is marked with “−” in the sense that measurement is impossible.

Claims (3)

Resin particle body (A);
Silica containing silica mother particles and silica child particles having an average circularity of 0.7 or more and 0.85 or less attached to the surface of the silica mother particles, and attached to the surface of the resin particle main body (A) Particles (B);
Resin particles comprising. Preparing an alkali catalyst solution containing an alkali catalyst at a concentration of 0.8 mol / L to 1.0 mol / L in a solvent containing alcohol;
A step of supplying silica particles by supplying tetraalkoxysilane so as to have a concentration of 0.7 mol / L or more and 1.8 mol / L or less without additionally supplying the alkali catalyst to the prepared alkali catalyst solution. When,
Attaching the obtained silica particles to the surface of the resin particle main body;
The manufacturing method of the resin particle which has this.   The tetraalkoxysilane is supplied into the alkaline catalyst solution at a supply rate of 0.001 mol / (mol · min) or more and 0.010 mol / (mol · min) or less with respect to the alcohol. The manufacturing method of the resin particle of description.