JP2001213970A - Method and apparatus for producing fine sphericl particle dispersion and fine spherical particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for simply, efficiently, continuously, and industrially producing fine spherical particles comprising a high-quality thermoplastic polymer excellent in resistance to heat and chemicals. SOLUTION: A thermoplastic resin is dispersed at its melting or softening temperature in a polysiloxane which is unreactive with and practically insoluble in the thermoplastic resin; then, the resultant dispersion is cooled; and the resin is separated from the polysiloxane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing spherical fine particles made of a thermoplastic resin. These spherical fine particles are used for powder molding materials, raw materials for sinter molding, fillers for thermoplastic resins and thermosetting resins, fillers for paints, filter agents, adsorbents for analytical columns, spacers for liquid crystals, toners,
Useful for powder coatings, cosmetic bases, etc.

[0002]

2. Description of the Related Art Generally, as a method for producing fine particles made of a thermoplastic polymer, a method of mechanically pulverizing a solid polymer is known. However, it is difficult to obtain fine particles having a uniform particle size by this method, and a special process such as a classifier is required to achieve the purpose.
Further, it was more difficult to obtain fine particles having a uniform shape (for example, spherical).

[0003] In the case of a vinyl polymer, a suspension polymerization method is known, and this method can solve the problem of uniform particle diameter to some extent, and can also obtain spherical particles.

However, in this method, applicable materials are limited to polymers derived from vinyl monomers. In addition, demands for heat resistance, chemical resistance, abrasion resistance, etc., which cannot be met by vinyl polymers, are increasing.

[0005] A number of attempts have been made to date for methods other than the above suspension polymerization method, for example, for obtaining spherical fine particles of a condensation thermoplastic resin.

For example, Japanese Patent Publication No. 2-122975 discloses that polyethylene terephthalate having a reduced viscosity of less than 0.25 is melted by heating and then sprayed from a nozzle.
A method for obtaining a spherical polyester resin is described. Further, Japanese Patent Application Laid-Open Nos.
No. 26025 describes a method of treating a polymer composition heated and melted by an atomizer having a special orifice.

[0007] However, these methods have practical problems, such as requiring special equipment, and being limited to resins having a low degree of polymerization or low melt viscosity.

Until now, the most frequently studied methods are to obtain a spherical fine particle by dissolving a thermoplastic resin in an organic solvent or the like, heating and melting the resin, and then cooling and precipitating the resin.

With respect to nylon, a nylon resin powder is dissolved by heating in a solvent such as a lower alcohol and the like.
A method of gradually re-precipitating by cooling is used, and the powder is used as a powder coating, a cosmetic base, and an adsorbent. A further improved production method is disclosed in JP-A-63-186738.
Japanese Patent Laid-Open Publication No. H11-15083 proposes a method for directly producing spherical nylon fine particles having a narrow particle size distribution.

Condensed polymers such as polyester and polycarbonate are disclosed in JP-A-51-79158, JP-B-60-31212, and JP-B-60-31.
No. 213 discloses poly (alkylene terephthalate)
With a halogenated aromatic solvent, tetrachloroethane, boiling point 2
A method is disclosed in which a spherical powder is obtained by heating and dissolving in an aromatic solvent at 30 ° C. or higher and then cooling.

Japanese Patent Application Laid-Open No. 2-215838 discloses that dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dimethyl adipate, dimethyl glutarate, which are called "intermediate solvents" for polyesters, polyamides and polycarbonates at or above their melting points. Esters, dimethyl succinate, monoethylene glycol, diethylene glycol, triethylene glycol,
A method is described in which a non-aggregated particle is obtained by heating and dissolving with a solvent such as tetraethylene glycol and then cooling it under conditions that cause solid / liquid phase separation.

However, with the exception of nylon, these methods involve the addition of a solidified organic solvent which has a long time to precipitate fine particles, a poor yield relative to the amount of charged polymer, is limited to crystalline resins, and There are various practical problems, such as the need for a step of extraction with an organic solvent, the inability to obtain perfect spherical fine particles, and the resulting particles being mechanically brittle.

As another method, a method is disclosed in which a polymer is treated in an incompatible medium to obtain spherical fine particles.

For example, Japanese Patent Application Laid-Open No. 61-57617 describes a method of obtaining a functional powder by vigorously stirring a thermoplastic resin in a medium in which the thermoplastic resin is not dissolved under the condition of the melting point or higher, followed by cooling. Have been. However, in the method using polyethylene glycol described above, only a copolymerized polyester having a low melting point can be micronized, and it is difficult to apply the method to a general-purpose thermoplastic resin having a high melting point.

Japanese Patent Application Laid-Open No. 7-3033 discloses that a liquid crystalline polymer having self-orientation can be dissolved in a non-liquid crystalline polymer soluble in a solvent at a temperature at which the liquid crystallinity can be maintained. A method is disclosed in which after heating and extruding, a non-liquid crystal polymer is removed with a solvent to obtain fine spherical particles. In this method, a large amount of a corrosive solvent that is highly toxic to the human body, such as trifluoroacetic acid, must be used to remove the non-liquid crystal polymer. There is a problem that it takes a long time for extraction.

As described above, an effective method for obtaining spherical fine particles of a thermoplastic resin has not been found yet.

[0017]

SUMMARY OF THE INVENTION The object of the present invention is to provide a method for industrially producing spherical fine particles of a thermoplastic polymer simply and efficiently.

[0018]

Means for Solving the Problems The present inventors have developed a method for industrially producing spherical fine particles of a thermoplastic resin having the above-mentioned preferable properties, particularly a thermoplastic resin produced by a known polycondensation method. As a result of intensive studies, the thermoplastic resin does not substantially react with the molten or softened thermoplastic resin at a temperature at which the thermoplastic resin melts or softens plasticity, at a temperature showing fluidity. After forcibly dispersing the molten or softened thermoplastic resin in a heating medium that does not substantially dissolve, and after quenching, separating the incompatible heating medium without extracting the heating medium, It has been found that the object can be achieved by using a non-reactive polysiloxane as the above, and the present invention has been accomplished based on this finding.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, the present invention is as follows. 1. Reactivity with the molten or softened thermoplastic resin and polysiloxane that does not substantially react with the melted or softened thermoplastic resin and does not substantially dissolve the melted or softened thermoplastic resin. A method for producing a dispersion of spherical thermoplastic resin particles by applying a shearing force to a mixture containing a silane compound.

2. Including a molten or softened thermoplastic resin and a polysiloxane that does not substantially react with the melted or softened thermoplastic resin and does not substantially dissolve the melted or softened thermoplastic resin. A method for continuously producing spherical fine particles, comprising cooling a dispersion of spherical fine particles of a thermoplastic resin obtained by applying a shearing force to a mixture, and then separating the dispersion from the polysiloxane.

3. At a temperature at which the thermoplastic resin is melted or softened, the thermoplastic resin and the polysiloxane that does not substantially react with the thermoplastic resin and do not substantially dissolve the thermoplastic resin are stirred with a high-speed shearing ability. The thermoplastic resin is continuously supplied to the container (A) equipped with the machine (B), the thermoplastic resin is dispersed in the polysiloxane by B, the obtained dispersion is continuously taken out of A, and immediately cooled. And then separating the polysiloxane from the polysiloxane.

4. 4. The method for continuous production of spherical fine particles according to the above item 3, wherein the thermoplastic resin is supplied in the vicinity of a stirrer (B) having a high-speed shearing ability.

5. 5. The method for continuously producing spherical fine particles according to the above 3 or 4, wherein the weight ratio of the thermoplastic resin and the polysiloxane in A satisfies the following formula (A-1). 0.01 ≦ PP / (PP + SP) (A-1) (In the above formula (A-1), PP represents the weight of the thermoplastic resin, and SP represents the weight of the polysiloxane.)

6. The polysiloxane has the following formula (1)

Embedded image

[In the formula (1), Si is a silicon atom.
R₁, R_Two, R_Three, R_Four, R_Five, R₆, R ₇And R₈Haso
Each independently represents a hydrogen atom, an OH group, an alkyl group having 1 to 10 carbon atoms.
Represents a kill group or an aryl group having 6 to 12 carbon atoms. m is
It is an integer of 1 to 300. ]
Continuous production of the spherical fine particles according to any one of the above 2 to 5
Construction method.

7. The polysiloxane has the following formula (1-
7. The method for continuously producing spherical fine particles as described in 6 above, wherein the method is a polysiloxane represented by any one of 1) and (1-2) or a mixture of both.

[0027]

Embedded image

In the formulas (1-1) and (1-2), S
i is a silicon atom, and Ph is a phenyl group.
X, Y and Z are each an independent integer of 1 to 300. ]

8. Including a molten or softened thermoplastic resin and a polysiloxane that does not substantially react with the melted or softened thermoplastic resin and does not substantially dissolve the melted or softened thermoplastic resin. The mixture also contains a reactive silane compound, and in A, 0.001 to 10 parts by weight of the reactive silane compound is blended with respect to 100 parts by weight of the polysiloxane. The method for continuously producing spherical fine particles according to any one of the above.

9. 9. The method for continuously producing spherical fine particles according to the above item 8, wherein the reactive silane compound is a silane coupling agent.

10. The silane coupling agent has the following formula (3-1)

Embedded image 10. The manufacturing method according to the above item 9, having a structure represented by the following formula:

11. The thermoplastic resin is characterized in that at least one polyester selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate,
11. The method for producing spherical fine particles according to any one of items 10.

12. The method for producing spherical fine particles according to any one of the above items 2 to 10, wherein the thermoplastic resin is a polyether ester.

13. The method for producing spherical fine particles according to any one of the above items 2 to 10, wherein the thermoplastic resin is polycarbonate.

14. In A, the temperature Th1 or Th of the mixture containing the thermoplastic resin and the polysiloxane
2 satisfies the following formula (B-1) or (B-2), and the temperature Tq1 or Tq2 of the solution containing polysiloxane in the cooling step satisfies the following formula (C-1) or (C-2) 14. The method for producing spherical fine particles according to any one of the above items 3 to 13, which comprises a step of: Tm ≦ Th1 ≦ Tm + 50 (B-1) Tp−50 ≦ Th2 ≦ Tp + 50 (B-2) Tm−100 ≦ Tq1 ≦ Tm ... (C-1) Tp-100 ≦ Tq2 ≦ Tp (C-2) [In the formulas (B-1) and (C-1), Tm is the melting point of the thermoplastic resin. And the formulas (B-2) and (C-2)
Medium, Tp is 3.9M using a Koka flow tester.
pa, a temperature at which the viscosity of the thermoplastic resin measured with a nozzle 1 mmφ × 10 mmL indicates 10,000 poise.
All units are in ° C. Formulas (B-1) and (C-1) are used when the thermoplastic resin is crystalline having a melting point, and formulas (B-2) and (C-2) are Used when the plastic resin is non-crystalline having no melting point. ]

15. A container (F) including a stirrer (B) having a high-speed shearing ability, an inlet (C) for injecting a thermoplastic resin, an outlet (D), and a polysiloxane supply port (E), An apparatus for continuously producing a dispersion of spherical fine particles of a thermoplastic resin, wherein an inlet (C) for injecting the thermoplastic resin is located near a stirrer (B) having a high-speed shearing ability.

The above-mentioned invention is characterized in that since it does not dissolve in a solvent by heating, it can avoid various problems associated with the "process of dissolving a polymer in a solvent followed by precipitation".

Further, when polysiloxane is used, the thermoplastic resin can be dispersed easily and unpredictably by the conventional dispersing method such as the case of polyethylene glycol, it can be stably processed even at a considerably high temperature, and it has a high shearing ability. In addition, there is a feature that stable fine particles can be obtained by combining with a stirrer having a certain characteristic, and that the use of polysiloxane makes it very easy to cool and wash and separate the fine particles.

The thermoplastic resin used in the present invention is not particularly limited, whether it is crystalline or amorphous.
Examples include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyetherester, polyarylate, polystyrene, polymethyl methacrylate, ABS resin, and AS resin.

More preferred are polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polyetherester.

Each of these thermoplastic resins is a thermoplastic polymer produced by a known polycondensation method.
It is a resin that has heretofore been difficult to produce spherical fine particles on an industrial level.

Such thermoplastic resins may be used as a blend of two or more kinds. In this case, it is possible to mix the pre-blend with the polysiloxane or to mix different resins with the polysiloxane.

In the present invention, the thermoplastic resin contains a polysiloxane that does not substantially react with the thermoplastic resin at a temperature at which the thermoplastic resin melts or softens, and does not substantially dissolve the thermoplastic resin. Force dispersion in heating medium.

In this case, when mixing the thermoplastic resin, the polysiloxane, and, in some cases, other agents, the temperatures of the thermoplastic resin, the polysiloxane, and the other agents are not necessarily set in advance. The temperature does not need to be adjusted to the temperature at which the thermoplastic resin melts or softens. For example, a method of blending a higher temperature polysiloxane with the thermoplastic resin may be considered.

The polysiloxane used here has a main chain of-
(Si-O)-is a linear polymer mainly composed of repeating units represented by the following formula: a thermoplastic resin, and exhibits fluidity at a temperature at which the thermoplastic resin melts or softens; Any material that does not substantially react and does not substantially dissolve the thermoplastic resin can be used without particular limitation.

When the polysiloxane is dissolved and compatible with the above-mentioned thermoplastic resin, the desired spherical particles cannot be obtained, but only an amorphous thermoplastic resin powder can be obtained. In addition, when reacting with the thermoplastic resin, a gel or the like is formed over the whole, and not only spherical resin particles cannot be obtained, but also the mixed system itself may be solidified.

In addition, as long as these properties are not impaired,
A part of the main chain may have another repeating unit, and a part may have a branched component.

As such a polysiloxane, for example, the following formula (1)

Embedded image Can be mentioned.

[In the above formula (1), Si is a silicon atom, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently a hydrogen atom, an OH group , An alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms. m
Represents an integer of 1 to 300. Examples of such an alkyl group include a methyl group and an ethyl group. Examples of the aryl group include a phenyl group, a tolyl group, and a naphthyl group. Preferred as a more specific example of the above formula (1) is
It is a polysiloxane represented by the following formulas (1-1) and (1-2).

[0050]

Embedded image

In the above formulas (1-1) and (1-2), P
h represents a phenyl group, and CH ₃ represents a methyl group. X, Y and Z each represent an independent integer of 1 to 300.

In the above dispersion, when the thermoplastic resin to be used is a crystalline polymer such as polyethylene terephthalate or polybutylene terephthalate, the “temperature of the mixture containing the thermoplastic resin and the polysiloxane” Th1
(Unit: ° C) preferably includes a step satisfying the following formula (B-1). When the thermoplastic resin to be used is an amorphous polymer such as polycarbonate, the “temperature of the mixture containing the thermoplastic resin and the polysiloxane” Th2 (unit: ° C) is a process satisfying the following formula (B-2). It is preferable to include All units are in ° C. Tm ≦ Th1 ≦ Tm + 50 (B-1) Tp−50 ≦ Th2 ≦ Tp + 50 (B-2)

In the above formula (B-1), Tm is the melting point of the crystalline polymer, and in formula (B-2), Tp is the softening point of the amorphous polymer. A temperature at which the viscosity measured at a pressure of 3.9 Mpa and a nozzle of 1 mmφ × 10 mmL indicates 10,000 poise.

If Th1 is smaller than Tm, the thermoplastic resin cannot be normally dispersed. If Th2 is smaller than (Tp-50) ° C., the resulting fine particles will not be spherical in shape, or the fine particles will easily aggregate during forced dispersion, resulting in a problem that a bulky thermoplastic resin is obtained as an impurity. There may be.

When Th1 is larger than (Tm + 50) ° C. or Th2 is larger than (Tp + 50) ° C., the thermoplastic resin forming the fine particles is decomposed, and the mechanical properties such as the strength of the obtained fine particles are deteriorated or the formed fine particles are deteriorated. There is a problem such as generation of a bad smell due to decomposition in the process, which is not preferable in some cases.

Here, the melting point was determined by a differential scanning calorimeter (DSC), and the softening point was 1 m using a “KOKA FLOW TESTER” manufactured by Shimadzu Corporation.
It can be measured under the conditions of a nozzle of mφ × 10 mm and a load of 294N. That is, it can be obtained as the temperature at the time when 1/2 of 1 g of the sample melts and flows out at an isothermal rate of 3 ° C./min.

The following formula (B-3) or (B-4)
More preferably, a step satisfying the following formula (B)
It is more preferable to include a step satisfying (5) or (B-6). All units are in ° C. Tm + 5 ≦ Th1 ≦ Tm + 40 (B-3) Tp ≦ Th2 ≦ Tp + 40 (B-4) Tm + 10 ≦ Th1 ≦ Tm + 30 (B-5) Tp + 10 ≦ Th2 ≦ Tp + 30 (B-6)

The above-mentioned crystalline polymer and amorphous polymer include those containing not more than 20% by weight of a copolymer component or a blend component, respectively. When the crystalline polymer and the amorphous polymer are dispersed as independent phases, it is desirable to adopt a value in the common range of Th1 and Th2.

The ratio at which the thermoplastic resin is dispersed in the non-reactive polysiloxane is represented by the following formula (A-1): 0.01 ≦ PP / (PP + SP) (A-1) It is preferable to satisfy. In the above formula (A-1), PP
Represents the weight (part) of the thermoplastic resin, and SP represents the weight (part) of the polysiloxane. When the value of PP / (PP + SP) is smaller than 0.01, the productivity of the obtained spherical fine particles may be deteriorated.

It is more preferable that the following formula (A-2) is satisfied, and it is more preferable that the following formula (A-3) is satisfied. 0.03 ≦ PP / (PP + SP) ≦ 0.9 (A-2) 0.05 ≦ PP / (PP + SP) ≦ 0.8 (A-3) From 0.9 If the size is large, the shape of the obtained fine particles will not be spherical, or aggregation of the fine particles will easily occur during forced dispersion,
Problems may occur, such as a lump of thermoplastic resin being obtained as an impurity.

In the dispersing step, the molten or softened thermoplastic resin is forcibly dispersed in the non-reactive polysiloxane.

For the distributed processing, an apparatus as shown in FIG. 1 can be used. However, the present invention is not limited by FIG.

In FIG. 1, a homogenizer 1 corresponding to the stirrer (B) having the high-speed shearing capability described in 3 above, an inlet 2 for injecting a thermoplastic resin, an outlet 3 and a supply port 4 for polysiloxane were provided. In the container 5, which corresponds to the container (A) described in the above 3 or the container (F) described in the above 15, the stirring blade 6 of the homogenizer sucks from the lower part thereof,
It is agitated so as to be discharged to the upper part, and an entrance 2 is provided immediately below.

Here, as a means for applying a shearing force for dispersion, various known ones including a diffuser type and a sand grinder type can be used, and particularly, a stirrer type, especially a homogenizer Is preferred. Homogenizers can be broadly classified into two types, a mechanical stirring type and an ultrasonic type. In the present invention, both the former type and the latter type can be used without any problem. Preferably, a mechanical stirring type homogenizer is used.

The “stirrer having high-speed shearing ability” referred to in the present application means a stirrer capable of stirring at a rotation speed of 1000 times / minute (1000 rpm) or more. Preferably satisfies the following formula (D-1). 5000 ≦ Rv ≦ 30000 (D-1) In the above formula (D-1), Rv represents the number of revolutions per minute (unit rpm) of the stirring blade of the mechanical homogenizer.

If the rotational speed Rv is less than 5000, the shape of the obtained spherical resin fine particles may not be spherical, or the fine particles may easily aggregate during forced dispersion, so that a lump of thermoplastic resin may be obtained as an impurity. .

If the rotation speed Rv is greater than 30,000, the thermoplastic resin forming the fine particles is decomposed, the mechanical properties such as the strength of the obtained fine particles are degraded, and the particle distribution of the obtained spherical resin fine particles is widened. The polydispersity index dw / dn, which will be described later, may be undesirably large.

Rv more preferably satisfies the following formula (D-2), and further preferably satisfies the following formula (D-3). 8000 ≦ Rv ≦ 28000 (D-2) 10,000 ≦ Rv ≦ 25000 (D-3)

The inlet for injecting the thermoplastic resin is preferably located near the stirrer (B) having a high-speed shearing ability in order to ensure sufficient dispersion. If this condition is not satisfied, the particle distribution of the obtained spherical resin fine particles becomes wide, and the polydispersity index dw / dn described later becomes large, which is not preferable.

Here, the phrase “in the vicinity of the stirrer (B)” specifically refers to a circle formed by the stirrer about the rotation axis when the stirrer of the stirrer (B) rotates. A cylindrical portion having a cross-sectional area, and the injection inlet is provided on the suction side or the discharge side portion of the stirring blade, which is within a distance of twice the radius of the circle from the plane including the circle. Means that. A distance of 1.5 times or less is more preferable instead of a distance of 2 times or less, and a distance of 1.0 or less is more preferable.
Especially preferred is within 5 times. Further, it is desirable that the discharge side of the stirring blade is vertically above and the injection inlet is on the suction side (that is, vertically below).

The time required for dispersing the thermoplastic resin, that is, the residence time of the mixture containing the thermoplastic resin and the polysiloxane in the container used for the dispersion is not particularly limited, but is usually 1 minute to 1 minute. 10 minutes.

If the residence time is longer than 10 minutes, the productivity of the obtained spherical fine particles may deteriorate, and the polymer may be thermally degraded to lower the quality. If the particle length is too short, there may be a problem that the shape of the obtained fine particles is not spherical, or the fine particles are easily aggregated during forced dispersion, and a massive thermoplastic resin may be obtained as an impurity. These residence times can be adjusted mainly by the supply rate of the thermoplastic resin, polysiloxane or the like.

Further, in order to keep the concentration of the polymer spherical fine particles dispersed in the polysiloxane constant, the polysiloxane is continuously supplied together with the thermoplastic resin to a container for dispersion treatment, and the supply rate of the thermoplastic resin and the polystyrene are controlled. It is preferable to keep the ratio with the supply rate of siloxane within a certain range.

The apparatus for supplying the molten polymer is not particularly limited, but an extruder generally used industrially can be preferably used.

In the present invention, at the time of the dispersion step,
In particular, when a polysiloxane represented by the above formula (1) is used, a polydispersity index dw / dn of a particle size distribution described later can be obtained by adding a reactive silane compound into the system.
Another characteristic of the present invention is that spherical tree particles having a particle size distribution closer to 1.0, that is, a relatively narrow particle size distribution with a uniform particle size can be obtained.

The reactive silane compound is preferably a silane coupling agent, and the silane coupling agent is preferably an alkoxysilane compound having a glycidyl group, and has a structure represented by the following formula (3-1). It is more preferred that there be.

[0077]

Embedded image

Here, the reactive silane compound is a silane derivative having an organic reactive group and reacting substantially with an organic compound mainly containing carbon to form a covalent bond with the organic compound. . Alkyl silane,
Examples include siloxane, polysiloxane, and polysiloxane oligomer. Specific organic reactive groups include
Examples include a carboxylic acid group, a carboxylic acid ester group, a hydroxyl group, a mercapto group, a glycidyl group, a vinyl group, an allyl group, an amino group, an isocyanate group, and a chloro group.

The reactive silane compound is added in an amount of 0.01 to 100 parts by weight of the polysiloxane.
A range of 10 parts by weight is suitable. If the amount is less than 0.01 part by weight, the particle size distribution of the obtained fine particles tends to be wide. Increasing the amount of addition makes it easier to obtain one with a uniform particle size distribution,
If the amount is too large, the thermoplastic resin may be gelled or may have a tendency to give off odor during dispersion. A more preferable addition amount is 0.05 to 8 parts by weight, and a still more preferable addition amount is 0.1 to 5 parts by weight.

After the thermoplastic resin is sufficiently dispersed in the polysiloxane as described above, it is cooled.

The cooling method may be any method such as cooling with a heat exchanger or mixing with another liquid. However, the same polysiloxane as used for dispersing the above-mentioned thermoplastic resin may be used at room temperature. It is also a preferable method to introduce a dispersion at a temperature lower than or equal to the temperature into the dispersion.

By rapidly cooling the temperature in the system to a temperature equal to or lower than the dispersion temperature of the thermoplastic resin in this way, aggregation of the fine particles generated in the system is suppressed.

The “temperature of the solution containing polysiloxane” Tq1 or Tq2 (unit: ° C.) in this cooling step is represented by the following formula (C-1) when the thermoplastic resin used is crystalline.
When the thermoplastic resin used is amorphous, the following formula (C-
It is preferable to include a step satisfying 2). When the crystalline polymer and the amorphous polymer are dispersed as phases independent of each other, it is desirable to adopt a value in the common range of Tq1 and Tq2. Tm-100 ≦ Tq1 ≦ Tm (C-1) Tp-100 ≦ Tq2 ≦ Tp (C-2) In the above formulas (C-1) and (C-2), Tm And Tp have the same meanings as in the above formulas (B-1) and (B-2).

Tq1 is smaller than (Tm-100) ° C.
Alternatively, when Tq2 is smaller than (Tp-100) ° C., the shape of the obtained spherical fine particles is not spherical, or the particle distribution of the obtained spherical fine particles is wide, and the polydispersity index dw /
dn may be undesirably large. Also, Tq
When 1 or Tq2 is larger than Tm or Tp, respectively, the shape of the obtained spherical fine particles may not be spherical,
Aggregation of fine particles tends to occur during cooling, and a lump of thermoplastic resin may be obtained as an impurity.

More preferably, a step satisfying the following formula (C-3) or (C-4) is included.
Alternatively, it is more preferable to include a step satisfying (C-6). Tm-80 ≦ Tq1 ≦ Tm-10 (C-3) Tp-80 ≦ Tq2 ≦ Tp-10 (C-4) Tm-60 ≦ Tq1 ≦ Tm-30 ... (C-5) Tp-60 ≦ Tq2 ≦ Tp-30 (C-6) In the above (C-1) to (C-6), the unit is ° C.

Here, the term “temperature of the liquid containing polysiloxane” means, in the case of cooling with a heat exchanger, the liquid in the mixture containing the thermoplastic resin and the polysiloxane, excluding the resin. When mixed and contacted with another liquid containing polysiloxane, this “other liquid” is also included. This solution is not necessarily one layer, but the temperature means its average value.

It is desirable that cooling be performed immediately as specified in the above item 3. That is, the cooling is performed with mixing by stirring or the like, but from Th1 to Tq1 or Th2.
It is desirable that the time from Tq2 to Tq2 be short. Specifically, the time is preferably within 5 minutes, more preferably within 3 minutes, even more preferably within 1 minute.

By cooling, the time in the upper air temperature range is 1
More than a minute is appropriate. If the time is less than 1 minute, the thermoplastic resin is not sufficiently hard, and may be deformed or condensed later. 3 minutes or more is more desirable, and 5 minutes or more is even more desirable.

Next, the spherical fine particles are separated from the liquid containing polysiloxane by filtration or the like. The liquid containing polysiloxane adhering and remaining on the separated spherical particles can be easily washed and removed with an organic solvent such as n-hexane or cyclohexane, and is usually dried to obtain spherical fine particles.

According to the present invention, a high-quality thermoplastic polymer having excellent heat resistance and chemical resistance, having a spherical shape having a diameter of 0.1 to 500 μm, being homogeneous and having relatively uniform particle diameters. Can be obtained.

The fine particles are preferably of the following formula (2-
It satisfies 1) and (2-2). 0.90 ≦ Pn ≦ 1.00 (2-1) 1 ≦ dw / dn ≦ 2.0 (2-2) In the above formula (2-1), Pn is Reflection electron microscope (SE
M) Of the photographic images obtained by observation, the size is 0.
In the range of 1 to 500 μm, the roundness P1 to P of each particle n present in a certain range of the photographed photograph
It is the number average roundness obtained by dividing the sum of h by the number.

In the above formula (2-2), dw / dn represents a polydispersity index of a particle size distribution measured by a light scattering / light diffraction method.

The light scattering / light diffraction method is a method for measuring the particle size distribution by utilizing the fact that the scattering pattern varies depending on the particle size. This is a known method for calculating the particle size distribution by calculating the content of each particle size closest to the actually measured scattering pattern using the calculated scattering patterns of various particle sizes.

From this, the polydispersity index dw / d is obtained by dividing the obtained weight average particle size dw by the number average particle size dn.
n is calculated.

In the production method of the present invention, various additives may be added to the dispersion step, if necessary, together with the thermoplastic resin. Such additives include, in addition to the reactive silane compounds described above, glass fiber, metal fiber, aramid fiber, ceramic fiber, potassium whisker, carbonate fiber, fibrous reinforcing agents such as asbestos, talc, calcium carbonate. , Mica, clay,
Various fillers such as titanium oxide, aluminum oxide, glass flake, milled fiber, metal flake, metal powder, heat stabilizers such as phosphate esters and phosphites, catalyst deactivators, oxidation stabilizers Additives such as a light stabilizer, a lubricant, a pigment, a flame retardant, a flame retardant auxiliary, and a plasticizer.

[0096]

According to the invention of the present application, spherical fine particles made of a thermoplastic polymer, in particular, are excellent in heat resistance and chemical resistance, are small in particle size, are relatively uniform, and are high quality thermoplastic polymers. Can be continuously, easily and efficiently industrially produced. Therefore, such spherical fine particles, powder molding material, sinter molding raw material,
Fillers for thermoplastic and thermosetting resins, fillers for paints, filter agents, adsorbents for analytical columns, liquid crystal spacers,
It is useful for toners, powder coatings, cosmetic bases, and the like.

[0097]

EXAMPLES Preferred embodiments of the present invention will be described below with reference to examples, but the present invention is not limited to the examples. In the examples, "parts" means "parts by weight". In the examples, various measurements were made by the following methods.

(Reduced viscosity) Unless otherwise specified, it is a value measured at 35 ° C. in a mixed solvent of phenol / tetrachloroethane (weight ratio 60/40) at a concentration of 1.2 (g / dl).

(Number average roundness) Reflection electron microscope SEM
The photograph was taken using a scanning electron microscope S-2400 manufactured by Hitachi, Ltd.

In a SEM photograph image of 1000 times, 89 μ
For each of i particles observed in an area of mx 117 μm in width, each having a size in the range of 0.1 to 500 μm, the photograph is rotated by a rotary table, and the entrance and exit of the particles in the radial direction are measured with a micrometer. A polar coordinate recording figure excluding the influence of eccentricity of tracing and mounting is obtained, a concentric template is applied to the figure, a circumcircle radius Rmax and an inscribed circle Rmin are read by the minimum area method, and the following equation (5-1) is used. Thus, the roundness Pi of each i-th particle was determined (see FIG. 2). Pi = Rmin / Rmax (5-1) The number average roundness Pn is represented by the following equation (5-2). Pn = ΣnPi / Σni ... (5-2)

Example 1 The device shown in FIG. 1 was used.
However, the apparatus did not open the upper part, and was made to be able to seal with nitrogen. That is, a stainless steel container having a capacity of 500 ml was fixed, and a mechanical stirring type homogenizer was installed such that the stirring portion was located at the center of the bottom. Then, a reflux pipe and a nitrogen introduction pipe were provided at the top of the vessel, and the system was sealed with nitrogen.

Further, an additional polysiloxane inlet was provided, and a heating heater capable of controlling an arbitrary temperature was attached to the outside, and a heat retaining treatment was performed.

Further, the temperature of 1.0 immediately below the homogenizer stirring blade
Attach a 2mm diameter nozzle (Polymer Injection Entrance) at the position of mm (the center of the nozzle is just below the center of the circle formed by the homogenizer stirring blade and separated by a distance equivalent to 0.1 times the radius of the circle) ), And an extruder for supplying the polymer to be melted was connected thereto.

While introducing nitrogen into the container at 5 L / min,
In the container, polysiloxane A of the above formula (1-1) (SRX-310 manufactured by Dow Corning Toray Silicone Co., Ltd.)
140 parts of the above formula (3-1) as a reactive silane compound
And 1 part by weight of the compound was added, and the vessel was heated.

After heating to 280 ° C., a polycarbonate resin (brand name L-1250, manufactured by Teijin Chemicals Ltd.) was melted from an extruder at a flow rate of 5 g per minute from the lower portion while stirring with a homogenizer at a rotation speed of 24,300 rpm. At the same time, polysiloxane containing the same ratio of the reactive silane compound as described above was continuously added at a flow rate of 20 g per minute.

The polymer overflowing from the side due to the addition
The polysiloxane dispersion liquid travels down the tube to reach the container 7 in FIG. 1, where 100 m of the cooled polysiloxane at room temperature (20 ° C.)
Injected into L. The resin particles dispersed in the polysiloxane were separated by filtration.

The operation was continued for 120 minutes after starting to inject the molten polycarbonate resin into the container 5. During this time,
The temperature of the mixture in the container 5 was kept at 280 ° C.

The temperature of the liquid containing the polysiloxane in the container 7 was maintained at 210 ° C. to 200 ° C. for 5 minutes, and then cooled to room temperature in another container over 30 minutes to remove the polycarbonate particles dispersed in the polysiloxane. Separated by filtration.

That is, 280 to 29 overflowing from the container 5
The 0 ° C. polymer / polysiloxane dispersion is allowed to cool for only a short time while traveling through the tube and then instantaneously cools to 210 ° C.
Cooled to 200C to 200C.

The obtained powder was found to be spherical resin fine particles from the SEM photograph. Tables 1 and 2 show photographs and the average particle diameter, number average roundness, and the like of the spherical fine particles.

The polycarbonate has a Tp of 24.
2 ° C.

[Examples 2 to 4] The items listed in Table 1 below and the polyetheresters were the same as those in Example 1 except that 150 ° C to 160 ° C was used instead of 210 ° C to 200 ° C.
Fine particles were obtained in the same manner as described above. From the SEM photograph, the obtained powder had a size of 1 to 20 μm, 1 to 50 μm, and 1 to 10 μm.
It was a spherical resin fine particle of μm. Table 1 and Tables 3 to 5 show the SEM photograph and the average particle diameter, number average circularity, and the like of the spherical fine particles.

The polyethylene naphthalate has a T
m is 253 ° C., Tm of polyethylene naphthalate is 25
At 1 ° C., the Tm of the polyetherester was 200 ° C.

Example 5 Fine particles were obtained in the same manner as in Example 1 except that no reactive silane compound was used. While the value of dw / dn in Example 1 was 1.51, it was 1.62 in Example 5.

[0115]

[Table 1]

It is to be noted that the method of the present invention can be carried out continuously as a whole, a part of the method can be carried out continuously, and the others can be carried out in a batch manner, or the whole can be carried out in a batch manner. However, in order to obtain stable quality, it is desirable to carry out the whole process continuously.

[Brief description of the drawings]

FIG. 1 shows a manufacturing apparatus according to the present invention.

FIG. 2 is a schematic diagram for calculating a number average roundness Pn of spherical fine particles.

FIG. 3 shows Table 2 of the present invention.

FIG. 4 shows Table 3 of the present invention.

FIG. 5 shows Table 4 of the present invention.

FIG. 6 shows Table 5 of the present invention.

[Explanation of symbols]

 1. Homogenizer 2. 2. Injection port for thermoplastic resin Exit 4 4. Polysiloxane supply port Container 6. Stirrer blade 7. container

Claims (15)

[Claims] 1. The molten or softened thermoplastic resin does not substantially react with the melted or softened thermoplastic resin, and does not substantially dissolve the melted or softened thermoplastic resin. A method for producing a dispersion of spherical thermoplastic resin particles by applying a shearing force to a mixture containing a polysiloxane and a reactive silane compound. 2. The molten or softened thermoplastic resin does not substantially react with the melted or softened thermoplastic resin, and does not substantially dissolve the melted or softened thermoplastic resin. A method for continuously producing spherical fine particles, comprising cooling a dispersion of spherical fine particles of a thermoplastic resin obtained by applying a shear force to a mixture containing polysiloxane and then separating the dispersion from the polysiloxane. 3. A thermoplastic resin and a polysiloxane that does not substantially react with the thermoplastic resin and does not substantially dissolve the thermoplastic resin at a temperature at which the thermoplastic resin melts or softens, at a high speed. The thermoplastic resin is continuously supplied to a container (A) provided with a stirrer (B) having a shearing ability, and the thermoplastic resin is dispersed in the polysiloxane by B. A method for continuously producing spherical fine particles, comprising taking out, immediately cooling, and separating from the polysiloxane. 4. The method for continuously producing spherical fine particles according to claim 3, wherein the thermoplastic resin is supplied near a stirrer (B) having a high-speed shearing ability. 5. The continuous production of spherical fine particles according to claim 3, wherein the weight ratio of the thermoplastic resin and the polysiloxane in A satisfies the following formula (A-1). Method. 0.01 ≦ PP / (PP + SP) (A-1) (In the above formula (A-1), PP represents the weight of the thermoplastic resin, and SP represents the weight of the polysiloxane.) 6. A polysiloxane represented by the following formula (1):[In the formula (1), Si is a silicon atom, and R₁, R_Two,
R_Three, R_Four, R_Five, R₆, R ₇And R₈Are each independently water
Elemental atom, OH group, alkyl group having 1 to 10 carbon atoms or carbon
Represents an aryl group having a prime number of 6 to 12. m is 1 to 300
Is a number. 6. The method according to claim 2, wherein:
The method for continuously producing spherical fine particles according to any one of the above. 7. The sphere according to claim 6, wherein the polysiloxane is a polysiloxane represented by any of the following formulas (1-1) and (1-2) or a mixture of both. A method for continuously producing fine particles. Embedded image [In the formulas (1-1) and (1-2), Si is a silicon atom, and Ph is a phenyl group. X, Y and Z
Is an independent integer of 1 to 300. ] 8. The molten or softened thermoplastic resin does not substantially react with the melted or softened thermoplastic resin and does not substantially dissolve the melted or softened thermoplastic resin. The mixture containing polysiloxane also contains a reactive silane compound, and in A, 0.001 to 10 parts by weight of the reactive silane compound is blended with respect to 100 parts by weight of the polysiloxane. A method for continuously producing spherical fine particles according to any one of claims 3 to 7. 9. The method for continuously producing spherical fine particles according to claim 8, wherein the reactive silane compound is a silane coupling agent. 10. A silane coupling agent represented by the following formula (3-
1) 10. The manufacturing method according to claim 9, having a structure represented by the following formula. 11. The thermoplastic resin according to claim 2, wherein the thermoplastic resin is at least one polyester selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate.
0. The method for producing spherical fine particles according to any one of the above. 12. The method according to claim 2, wherein the thermoplastic resin is a polyetherester. 13. The method according to claim 2, wherein the thermoplastic resin is a polycarbonate. 14. In A, the temperature Th1 or Th2 of the mixture containing the thermoplastic resin and the polysiloxane satisfies the following formula (B-1) or (B-2), and the polysiloxane in the cooling step The method for producing spherical fine particles according to any one of claims 3 to 13, comprising a step in which the temperature Tq1 or Tq2 of the solution containing the following formula (C-1) or (C-2) is satisfied. Tm ≦ Th1 ≦ Tm + 50 (B-1) Tp−50 ≦ Th2 ≦ Tp + 50 (B-2) Tm−100 ≦ Tq1 ≦ Tm ... (C-1) Tp-100 ≦ Tq2 ≦ Tp (C-2) [In the formulas (B-1) and (C-1), Tm is the melting point of the thermoplastic resin. And the formulas (B-2) and (C-2)
Medium, Tp is 3.9M using a Koka flow tester.
pa, a temperature at which the viscosity of the thermoplastic resin measured with a nozzle 1 mmφ × 10 mmL indicates 10,000 poise.
All units are in ° C. Formulas (B-1) and (C-1) are used when the thermoplastic resin is crystalline having a melting point, and formulas (B-2) and (C-2) are Used when the plastic resin is non-crystalline having no melting point. ] 15. A stirrer (B) having a high-speed shearing ability.
A container (F) provided with an inlet (C) for injecting a thermoplastic resin, an outlet (D), and a supply port (E) for polysiloxane, the inlet (C) for injecting a thermoplastic resin. ) Is in the vicinity of a stirrer (B) having a high-speed shearing ability, wherein the thermoplastic resin spherical fine particle dispersion is continuously produced.