JPH08169959A - Method for producing polycarbonate resin powder - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for easily producing a polycarbonate resin powder having a very small residual organic solvent and a uniform particle size. [Structure] A solid polycarbonate resin containing an organic solvent is supplied to an extruder, finely pulverized in the extruder, then extruded without melting or melting, and then cut or pulverized to obtain a vapor ejector of a polycarbonate resin powder. while transporting with consists in drying after removing the organic solvent, steam ejector pressure of polycarbonate resin powder or granular material suction portion of -50mmH ₂ O following polycarbonate resin powder-like body, characterized in that to hold the Production method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polycarbonate resin powder particles. More specifically, it relates to a method for easily producing a polycarbonate resin powder having a very small residual organic solvent amount and a uniform particle size.

[0002]

2. Description of the Related Art Polycarbonate resins are usually produced by a so-called solution method in which an alkaline aqueous solution of a dihydric phenol is reacted with phosgene in the presence of an organic solvent such as methylene chloride. After that, the organic solvent is removed to give a granular material, which is then subjected to a granulation step, and then subjected to a drying step. As a method for obtaining a powder or granular material by removing an organic solvent from a polycarbonate resin solution, for example, a method of bringing the polycarbonate resin solution into contact with hot water or steam to form flakes or powder (Japanese Patent Publication No. 36-11231, Japanese Patent Publication No. JP-B-40-9843, JP-B-45-9875, JP-B-48-43752, JP-B-54-12
2393), and a method of gelling by concentration or cooling to make powder (Japanese Patent Publication No. 36-21033, Japanese Patent Publication No. 38-22497, Japanese Patent Publication No. 40-12379, Japanese Patent Publication No. 45-9875). , Japanese Examined Sho 47-414
21 and JP-A-51-41048) are known. However, a large amount of organic solvent still remains in the powder and granules (including flakes) obtained by these methods, and it is difficult to sufficiently remove this residual organic solvent by ordinary drying.

As a method of removing this residual organic solvent, a method of mixing with warm water having a boiling point of the residual organic solvent or higher and distilling it has been proposed. However, this method increases not only the organic solvent but also the hot water, which increases the energy cost. In addition, the powder and granules obtained by this method,
Several hundred to several thousand ppm of organic solvent remains. In order to further reduce this residual organic solvent, it is necessary to dry it for a long time at high temperature or pelletize it with an extruder equipped with a vacuum vent, and still dozens to hundreds of ppm of organic solvent remain, and These products cannot avoid adverse effects on heat resistance, hue and physical properties.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for easily producing a polycarbonate resin powder having a very small residual organic solvent and a uniform particle size.

As a result of earnest studies aimed at achieving the above object, the present inventor has continuously supplied a solid polycarbonate resin containing an organic solvent to an extruder, finely pulverized in the extruder, and then melted or dissolved. Without removing the organic solvent while extruding, cutting or crushing the powder obtained by transporting it with a steam ejector, the amount of organic solvent can be reduced in a short time, and the powder or granular material can be extremely retained by drying. It was found that a polycarbonate resin powder having a small amount of organic solvent can be obtained. Further, by attaching a die having pores at the extruder outlet, and cutting the strand-shaped polycarbonate resin extruded from the pores to a desired length, it is possible to obtain a polycarbonate resin powder having a uniform particle size. Heading, completed the present invention.

[0006]

According to the present invention, a solid polycarbonate resin containing an organic solvent is fed to an extruder,
Extruded without melting or dissolving after finely pulverized in the extruder, it consists of drying after removing the organic solvent while transporting the polycarbonate resin powder obtained by cutting or pulverizing using a steam ejector, Adjust the pressure of the polycarbonate resin powder granule suction part of the ejector to -50.
A method for producing a polycarbonate resin powder, which is characterized by holding at a value of mmH ₂ O or less.

The organic solvent referred to in the present invention is mainly composed of at least one good solvent, and may be mixed with a poor solvent or a non-solvent. Good solvent, poor solvent and non-solvent as used herein are "polycarbonate" by WF CHRISTOPHER, DWFOX.
Solvents corresponding to “Good Solvent” and “Fair Solvent” in Table 3-1 on pages 32-33, 1962 are good solvents, “Poor Solvent”, “Very Poor Solvent”
And “Weak Solvent” are poor solvents, “Nons
Solvents that fall under “olvent” are non-solvents. Representative examples of good solvents are methylene chloride, tetrachloroethane, monochlorobenzene, etc., and representative examples of poor solvents are benzene, toluene, acetone, etc. Representative examples of the solvent include hexane, heptane, etc. Such poor solvent and non-solvent may be used alone or in combination of two or more kinds.

The polycarbonate resin referred to in the present invention is an aromatic polycarbonate resin obtained by reacting a dihydric phenol with a carbonate precursor. The dihydric phenol used here has the following general formula

[0009]

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[In the formula, R is a substituted or unsubstituted alkylene group having 1 to 9 carbon atoms, an alkylidene group, a cycloalkylidene group, -S-, -SO-, -SO _2- , -O- or -C.
O-, X ₁ and X ₂ are an alkyl group having 1 to 3 carbon atoms or a halogen atom, and m and n are 0, 1 or 2. ] One type or two or more types of dihydric phenols selected from dihydric phenols and 4,4'-dihydroxydiphenyl represented by the formula, and particularly 2,2-bis (4-hydroxyphenyl) propane (commonly called bisphenol A) is It is preferably used. Other dihydric phenols include, for example, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4
-Hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ether, 4,4-dihydroxydiphenyl and the like. Furthermore, 2,2-bis (3,5-
Examples thereof include halogenated bisphenols such as dibromo-4-hydroxyphenyl) propane. Examples of the carbonate precursor include carbonyl halide, diaryl carbonate, haloformate and the like, and specific examples include phosgene, diphenyl carbonate and dihaloformate of dihydric phenol.

When the polycarbonate resin is produced by reacting the above dihydric phenol with the carbonate precursor, a catalyst, a molecular weight modifier, an antioxidant, etc. may be used, if necessary. It may be a branched polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound or a mixture of two or more kinds of polycarbonate resins. The molecular weight of the polycarbonate resin is not particularly limited. For example, in the case of a polycarbonate resin obtained by using bisphenol A as the dihydric phenol and phosgene as the carbonate precursor,
A methylene chloride solution having a concentration of 0.7 g / dl and a specific viscosity (η _SP ) measured at 20 ° C. of 3.00 or less are preferable, and those having a specific viscosity of 0.19 to 1.50 are particularly preferable.

The polycarbonate resin used in the present invention is
It is a solid polycarbonate resin containing an organic solvent produced by an arbitrary method, and its shape may be arbitrary such as powder, granules, pellets, flakes, and lumps. There is no need to limit the size as long as there is no problem with the biting property of the extruder, and if there is a problem with the biting property, pretreatment such as crushing may be performed. Hereinafter, such solid polycarbonate resin is referred to as polycarbonate resin powder.

The amount of the organic solvent contained in the polycarbonate resin powder is not particularly limited, but if it is too large, it becomes difficult to handle the polycarbonate resin as powder, and if it is too small, the method of the present invention is adopted. Since it is not necessary, it is usually in the range of 50 ppm to 65% by weight. The amount of the organic solvent in the present invention is% by weight based on the total weight of the organic solvent and the polycarbonate resin. Further, the water content of the polycarbonate resin powder is not particularly limited, but since it is necessary that a predetermined amount of water be present in the finely pulverizing stage in the extruder to be described later, the water content of more than the undried saturated water content is higher. Those having water content are preferable.

In the present invention, the above-mentioned polycarbonate resin powder is supplied to an extruder, finely pulverized in the extruder, and then extruded without melting or melting. In the finely pulverizing stage in the extruder, the amount of the organic solvent in the granular material is preferably 5 to 65% by weight, particularly preferably 10 to 65% by weight. If the amount of the organic solvent is more than 65% by weight, it becomes difficult to pulverize, and if it is less than 5% by weight, the load of the extruder becomes large and the pulverization becomes difficult. It's hard to get a body.
Especially, the range of 15 to 45% by weight is preferable. When the amount of the organic solvent is not appropriate, it may be adjusted by adding or removing the organic solvent. When the amount of the organic solvent is small, an organic solvent, a polycarbonate resin solution, or a polycarbonate resin powder containing a large amount of the organic solvent may be added in a predetermined amount. In particular, it is preferable to add a polycarbonate resin solution obtained by a solution method because the granulation step of this solution can be omitted. In addition, it may be added to the polycarbonate resin powder or granular material supplied to the extruder, or may be added from the hopper or vent hole of the extruder. When the amount of the organic solvent is large, a polycarbonate resin powder having a small content of the organic solvent may be added, or the excess organic solvent may be removed by heating in advance. Further, the temperature of the extruder to be used may be adjusted so that the supplied polycarbonate resin powder or granule does not melt or dissolve, and excess organic solvent may be removed from the vent hole. When adjusting the amount of the organic solvent, it is preferable to mix them uniformly.

In the fine grinding stage in the extruder, 5% by weight
The presence of the above water is preferable. If the amount of water is less than 5% by weight, the finely pulverized powders will adhere to each other, making it difficult to obtain the desired polycarbonate resin powder granules with extremely small residual organic solvent. Further, if the amount of water is too large, not only the energy for drying the obtained powder and granules increases, but also the strength of the powder and granules obtained becomes weak,
Since it is easily crushed by impact, it is preferably 120% by weight or less. Especially, it is 6 to 80 because powdery granules having excellent drying property and hard to be crushed by impact are obtained.
It is preferred that the content be% by weight. If the amount of water is not appropriate,
It may be adjusted by addition or removal of water, addition of polycarbonate resin powder or the like. When the amount of water is large, for example, a polycarbonate resin powder having a low water content is added or dehydrated by a centrifuge or the like. Just remove it. If the amount of water is small, it is sufficient to add a predetermined amount of water or a polycarbonate resin powder having a high water content, and in addition, even if added to the polycarbonate resin powder supplied to the extruder, the polycarbonate resin You may add from the vent hole etc. of the extruder which is supplying the granular material. Further, in adjusting the amount of water, it is preferable to mix them uniformly. The amount of water referred to in the present invention is% by weight with respect to the polycarbonate resin, and may be hereinafter referred to as water content.

In the fine pulverization stage, most of the polycarbonate resin powder, usually 90% or more, has a diameter of 50 μm or less,
It is preferably pulverized to 40 μm or less, particularly preferably 30 μm or less. If most of them are not finely pulverized to have a diameter of 50 μm or less, it becomes difficult to obtain a desired polycarbonate resin powder having a very small amount of residual organic solvent. The polycarbonate resin powder obtained by the method of the present invention is folded into two or more pieces, and the cross section thereof is 100 times as observed by an electron microscope.
If it is enlarged to about 0 times, the size of the polycarbonate resin finely pulverized in the extruder can be easily confirmed.

When the finely pulverized polycarbonate resin is extruded, it is compressed without being melted or dissolved and extruded as an agglomerate of fine powder. If you melt or melt here,
It is not possible to obtain a desired polycarbonate resin powder containing very little residual organic solvent. In addition, when extruding, most of the water present in the pulverizing step should be left to prevent the fine powders from adhering to each other during agglomeration.

The extruder used in the present invention may be of any type as long as it has a fine pulverizing function capable of finely pulverizing the polycarbonate resin powder particles in the extruder to a diameter of 50 μm or less, and has a kneading function and a deliquoring function. It is preferable to combine them with a kneading disk, a seal ring or the like to impart these functions. Examples of the extruder include a single-screw or multi-screw screw type extruder, a plunger type extruder, or an extruder having a mechanism such as an injection molding machine having an inner screw. Depending on the solvent concentration in the polycarbonate resin powder and extrusion conditions, the internal temperature and internal pressure of the cylinder may cause problems such as dissolution and melting of the polycarbonate resin.A jacket with a temperature control mechanism to avoid such problems. It is preferable to use an attached cylinder or screw.
Also a cylinder with a vent, a cylinder with a taper,
A screw having compression may also be used. For the liquid removing function, a punching plate or a slit for liquid removing may be provided on all or part of the cylinder, or a liquid removing mechanism may be provided on the ground side. Most of the excess water contained in the polycarbonate resin granules, such as separated water and attached or contained water, is separated on the opposite side of the die or by a punch plate or slit. The openings of the gland and the punch plate, the clearance of the slit, etc. are not particularly limited and may be appropriately selected depending on the particle diameter of the polycarbonate resin powder in the extruder, the water content of the polycarbonate resin powder, and the like.

When extruding the finely pulverized polycarbonate resin, a die having pores is attached to the exit of the extruder, and the extruded strand-like aggregated polycarbonate resin is cut into a desired length to obtain a uniform particle size. A granular material is obtained. Further, at the time of extrusion, it is preferable to provide the screw tip with a function of delivering the polycarbonate resin fine powder to just before the die. The die may be either a pre-extrusion type that extrudes in the same direction as the extrusion axis or a horizontal extrusion type that extrudes at a right angle to the extrusion axis or in the axial direction. The shape is not particularly limited, but is generally circular from the working surface of the hole. The structure of the holes of the die is preferably 0.1 to 5 mm, more preferably 0.5 to 3 mm, from the viewpoints of extrusion capacity, drying efficiency, handleability, etc.
The land may have the same hole diameter and pass through the die, or may be a multi-stage communication hole having different hole diameters with the same hole axis. From the standpoints of strength of the obtained powder and granules, discharge pressure, strength of die, etc., the ratio of land (L) to hole diameter (D) is preferably L / D in the range of 1 to 10. When a die having multi-stage communication holes is used, the diameter of the holes and the lands need only be such that extrusion is not hindered. Further, it may be a die having a taper. The strand-shaped polycarbonate resin extruded from the die can be cut by any method. A preferred example is a method of cutting by rotating a propeller attached so as to be parallel to the die surface. The length of the granular material can be adjusted by the mounting position of the propeller, the rotation speed, and the like.

The polycarbonate obtained in the present invention
While transporting resin powder particles using a steam ejector
Remove the organic solvent. Normal poly by doing this
Carbon carbonate resin granules in water are heated to dissolve organically.
The organic solvent can be reduced in a shorter time than the method of removing the medium.
Energy consumption can be reduced. Also, equipment reduction
It can be changed. Drive steam pressure depends on transportation distance, throughput, etc.
It can be selected appropriately, but if the driving steam pressure is too low
Transport is difficult and removal of organic solvent is too high
Since the amount of steam not used for
1-100kg / cm ²And 3 to 50 kg / cm²Is preferred
Yes.

When supplying the polycarbonate resin powder particles to the steam ejector, the pressure of the suction part is set to -50 mmH ₂ O.
It is necessary to keep below. By keeping the pressure below -50 mmH ₂ O, it will come into contact with steam rapidly from the depressurized state, so that the amount of residual organic solvent is remarkably increased as compared with the method of heating the normal water slurry to remove the organic solvent. It becomes possible to reduce.

Further, depending on the mounting angle of the steam ejector, it may be difficult to smoothly transport the polycarbonate resin powder particles. For example, when the vapor ejector or the suction unit is attached in a horizontal direction at an angle of repose or less of the obtained polycarbonate resin powder, it becomes difficult to smoothly transport the polycarbonate resin powder. In such a case,
By injecting steam from the polycarbonate resin powder granule suction part, the polycarbonate resin powder granules can be transported very smoothly, reducing the amount of polycarbonate resin powder granules that accumulate in the ejector part and cause a decrease in molecular weight and deterioration of product hue. it can. Of course, even if the angle of repose is not less than the angle of repose, if the flow of the powder or granular material to the suction unit is poor, steam may be injected into the suction unit. The angle of repose of the polycarbonate resin granules varies depending on the water content, the shape of the granules, etc., and cannot be unconditionally limited but is usually about 60 degrees.

The resulting polycarbonate resin powder granules are
It is possible to dry continuously or batchwise without the need for deliquoring. At this time, if the liquid is removed using a centrifugal dehydrator, a wire net, an air slide method, etc., the amount of water in the dryer system is reduced, and it is possible to reduce the generation of foreign matter due to the corrosion of the equipment and the drying energy. . For drying, any device may be used alone or in combination of two or more. Examples of the drying device include a hot air circulation dryer, a steam tube dryer, a pow heater, a hopper dryer, a tower dryer, a paddle dryer, and a multi-fin dryer. In the deorganization solvent or the drying step, extraction or addition treatment with a poor solvent or a non-solvent may be performed.
The polycarbonate resin powder thus obtained may contain any stabilizer, additive, filler, etc. at any stage, if necessary.

[0024]

EXAMPLES The present invention will be further described with reference to the following examples. In the examples,% is% by weight, methylene chloride content is% by weight based on the total weight of methylene chloride and polycarbonate resin, and water content is% by weight with respect to the polycarbonate resin. The evaluation was based on the following method. (1) Amount of methylene chloride: Chlorine content was determined by analysis with a total organic halogen analyzer [TOX manufactured by Mitsubishi Kasei Co., Ltd.]. (2) Amount of n-heptane: Gas chromatography [Co., Ltd.]
Hitachi Model 263] was used for the column packing using dioctyl sebacate. (3) Specific viscosity (η _SP ): Polycarbonate resin 0.7g
Was dissolved in 100 ml of methylene chloride at 20 ° C.
Measured with an Ostworld viscometer. (4) Average particle size (mm) and particle size distribution (n): Measured in accordance with the particle size measuring method described in Chapter 2, Section 2.4, "Granulation Handbook" edited by Japan Powder Industry Association. Rosin Ramlar n
Is an index of the particle size distribution, and the larger the value, the narrower the size distribution.

[Example 1] (A) A 15% methylene chloride solution of a polycarbonate resin having a specific viscosity of 0.426 obtained from bisphenol A and phosgene by a conventional method was put into a kneader charged with warm water kept at 42 ° C. To remove methylene chloride and then coarsely pulverize to a liquid temperature of 38 ° C, a concentration of powder and granules of 25%, a methylene chloride content of 3
A 0% water slurry was obtained. (B) A twin-screw extruder with a diameter of 30 mm and a L / D of 25 with a temperature control jacket on the cylinder (Imagai Tekko PCM
-30) and use a hole with a diameter of 2 mm and a land of 6 mm at the outlet.
A die having 20 pieces is provided, and a cutting machine (a single-blade propeller having a length of 50 mm) is arranged at an interval of 4 mm in front of the die, the jacket temperature is 15 ° C., the screw rotation speed is 80 rpm, and the cutting machine rotation speed is 200 rpm. Set to. The slurry obtained in the above (A) was continuously supplied to the hopper of the extruder, pulverized in the extruder and then extruded to obtain a granular body. The extrusion rate is 30
It was kg / hour. This granular material had a water content of 30% and a methylene chloride content of 25%. (C) Drive steam pipe diameter 380 mm, nozzle diameter 2.2 mm,
Vapor ejector with suction chamber diameter 750mm, diffuser diameter 380mm, diameter 250mm, horizontal part 6m, vertical part 1
A 1m transport pipe was installed. Drive steam pressure 4kg / cm ²
The granular material obtained in (B) above was placed in a horizontal vapor ejector having a vertical suction section above the vapor ejector.
The organic solvent was removed while being charged and transported at 5 kg / hour. At this time, steam is injected from the suction unit to reduce the pressure of the suction unit to -1.
Hold at 00 mm H ₂ O. The obtained granules have a water content of 15
%, And the methylene chloride content was 1.2%. The granules were dried at 145 ° C. for 6 hours with a hot air circulation dryer to obtain a residual methylene chloride content of 6.3 ppm and a bulk density of 0.59 g / ml.
About 95% of the particles passed through 8 mesh, and granules remained in all 14 mesh were obtained. When the broken surface of this granular material was magnified 1000 times with an electron microscope, the diameter was 2 to 20 μm.
It was confirmed to be an aggregate of fine powder of m 2.

[Embodiment 2] The driving steam pressure was set to 16 kg / cm ^2.
Except that the water content is 13% in the same manner as in Example 1 except that
Granules with a methylene chloride content of 0.7% were obtained. The granules were dried with a hopper dryer at 145 ° C. for 6 hours to obtain a residual methylene chloride content of 5.0 ppm and a bulk density of 0.59 g /
About 95% of the powder passed through 8 mesh, and all the particles remained in 14 mesh. When the broken surface of this granular material was magnified 1000 times with an electron microscope, the diameter was 2 to 2
It was confirmed to be an aggregate of fine powder of 0 μm.

[Example 3] An agglomerate obtained in the same manner as in Example 1 (B) except that the die and the cutter were removed, was crushed by a hammer mill with a screen having an opening of 5 mm to obtain a water content of 32.
%, And a methylene chloride content of 27% was obtained. The powder and granules were placed in the same steam ejector as in Example 1 to obtain powder and granules having a water content of 18% and a methylene chloride content of 1.0%. The powder and granules were mixed with a paddle dryer at 145 ° C for 6 minutes.
After drying for an hour, a residual granular methylene chloride content of 2.2 ppm, a bulk density of 0.63 g / ml, an average particle size of 0.83 mm and an n of 1.43 were obtained. When the folded surface of this granular material was magnified 1000 times with an electron microscope, it was confirmed to be an aggregate of fine powder having a diameter of 2 to 20 μm.

Example 4 A polycarbonate resin obtained by mixing 25% of n-heptane with a 15% methylene chloride solution of a polycarbonate resin having a specific viscosity of 0.426 obtained by a conventional method from bisphenol A and phosgene. Example 1 (A) except using the methylene chloride solution of
In the same manner as described above, an aqueous slurry having a powder / granule concentration of 25% and methylene chloride of 20% was obtained. This slurry was extruded in the same manner as in Example 1 (B) to obtain granules having a water content of 27% and a methylene chloride content of 22%. The extrusion rate was 28 kg / hour.

Driving this granular material at a steam pressure of 10 kg / c
The organic solvent was removed while being fed at a rate of 20 kg / hr into a vertical vapor ejector having a m ² and a suction part provided on the upper part.
At this time, the injection of steam from the suction part was stopped. The obtained granules were transferred onto a wire net and blown with 20 l / min of air for 5 minutes. The obtained granular material had a water content of 5% and a methylene chloride content of 0.5%. The granules were dried at 145 ° C. for 6 hours by a hot air circulation type dryer, the residual methylene chloride amount was 0.3 ppm, the residual n-heptane amount was 40 ppm, the bulk density was 0.59 g / ml, and about 95% passed through 8 mesh. Then, all of the granules remaining in 14 mesh were obtained. When the folded surface of this granular material was magnified 1000 times with an electron microscope, it was confirmed to be an aggregate of fine powder having a diameter of 2 to 20 μm.

[Comparative Example 1] The polycarbonate resin powder granules water slurry obtained in Example 1 (A) was crushed by a hammer mill with a screen having 5 mm openings and gradually heated to 95 ° C under stirring and held for 1 hour. After that, the product was dehydrated by a centrifugal dehydrator to obtain a granular material having a water content of 18% and a methylene chloride content of 2%. The granules were dried at 145 ° C. for 6 hours with a hot air circulation dryer.
After drying for an hour, the amount of residual methylene chloride was 85 ppm and the bulk density was 0.
The average particle size was 62 g / ml, the average particle size was 0.51 mm, and n was 1.02. When the powder and granules were magnified 1000 times by an electron microscope, it was confirmed that the powder and granules had a particle diameter of almost 70 to 3000 μm and were not aggregates of fine powder.

[Comparative Example 2] The granular material obtained in (B) of Example 1 was poured into warm water maintained at 45 ° C with stirring, and gradually added to 9
The temperature was raised to 5 ° C. and kept for 1 hour and then dehydrated by a centrifugal dehydrator to obtain granules having a water content of 8% and a methylene chloride content of 2%. The granules were dried for 6 hours at 145 ° C. by a hot air circulation dryer, the residual methylene chloride content was 9 ppm, and the bulk density was 0.
60g / ml, about 95% passed through 8 mesh, all 14
A granular material remaining on the mesh was obtained. When the folded surface of this granular material was magnified 1000 times with an electron microscope, it was confirmed to be an aggregate of powder having a diameter of 2 to 20 μm.

[0032]

EFFECTS OF THE INVENTION According to the present invention, a polycarbonate resin powder having very little residual solvent can be obtained, and the obtained polycarbonate resin powder is very easy to handle. It is something.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiro Kana 1-6-21 Nishishinbashi, Minato-ku, Tokyo Inside Teijin Kasei Co., Ltd.

Claims (3)

[Claims] 1. A polycarbonate resin powder obtained by supplying a solid polycarbonate resin containing an organic solvent to an extruder, finely pulverizing in the extruder, then extruding without melting or dissolving, and cutting or pulverizing. A polycarbonate resin powder, characterized by comprising drying after removing an organic solvent while transporting using a steam ejector, and maintaining the pressure of the polycarbonate resin powder granule suction part of the vapor ejector at −50 mmH ₂ O or less. Body manufacturing method. 2. The method for producing a polycarbonate resin powder or granular material according to claim 1, wherein steam is introduced from a suction portion of the polycarbonate resin powder or granular material to facilitate the transportation of the polycarbonate resin powder or granular material. 3. The step of extruding the finely pulverized polycarbonate resin from an extruder and cutting or pulverizing the finely pulverized polycarbonate resin is a step of extruding and pulverizing the finely pulverized polycarbonate resin through the pores of a die attached to the exit of the extruder. Or claim 2
A method for producing the polycarbonate resin powder according to the description.