JP2018144312A - Method for producing thermoplastic resin composition pellets - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce high quality thermoplastic resin composition pellets by reducing oxidation degradation products and suppressing occurrence of gum at an orifice opening.SOLUTION: A method for producing thermoplastic resin composition pellets has a step of compacting and pulverizing a polyphenylene ether resin to obtain a compacted and crushed polyphenylene ether resin, a step of melt-kneading the compacted pulverized polyphenylene ether resin and a thermoplastic resin (A) to obtain a thermoplastic resin composition, a step of obtaining the thermoplastic resin composition strand with an average retention time T of the thermoplastic resin composition at an orifice of 1 to 20 milliseconds using an extruder fitted with a die plate having the plurality of orifices each having a diameter D of 3 to 8 mm and a length L of 0.3 to 2.0 times an inner diameter D, and a step of pelletizing the thermoplastic resin composition strand to obtain a thermoplastic resin composition pellet.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a thermoplastic resin composition pellet, and particularly relates to a method for producing a thermoplastic resin composition pellet using a polyphenylene ether resin.

  Polyphenylene ether resins are widely used as electrical and electronic parts, OA parts, audio-visual equipment parts, automobile parts, and the like as materials having excellent heat resistance, dimensional stability, and flame retardancy. Moreover, in the manufacture of the various parts described above, a material containing polyphenylene ether resin is often used in the form of pellets having a thickness and length of about several millimeters.

  Since this polyphenylene ether resin is usually composed of secondary particles in which fine primary particles are gathered, even if the particle size is large, the specific surface area is large, so that the amount of oxygen adhering to the surface of the particles is large. For this reason, there is a problem that ordinary polyphenylene ether resins tend to generate a relatively large amount of oxidative degradation when being molded using an extruder.

  As a countermeasure to this problem, a technique has been proposed in which the oxygen concentration is reduced by strengthening the oxygen concentration management of the feeder and the extruder (see Patent Document 1).

  On the other hand, as one method for producing pellets having a thickness and length of several millimeters from a material containing a thermoplastic resin, a molten thermoplastic resin composition is bonded to a die part at the end of an extruder. A method of discharging a plurality of molten strands from an orifice (hole outlet), cooling the molten strands with a cooling device, and cutting with a pelletizer is generally well known.

  Here, when a normal die plate is used, there is a problem that a lump of a melted resin composition, also referred to as “meani”, is generated at the orifice of the die plate and the preparation of the strand becomes unstable.

As a technique for solving this problem, a technique has been proposed in which gas is blown to an orifice of a die plate to remove the mains (see Patent Document 2). In addition, as a method of stabilizing all the discharged strands, the number of orifices of the die plate is set to 30 or more, and the length of the orifices located at both ends of the die plate is set to be longer than the length of the orifice located at the center of the die plate. A technique for reducing the size is also proposed (see Patent Document 3). Further, Patent Document 4 discloses a technique in which the orifice length (land length) of the die portion is less than 20 mm, and the shear rate of the die portion is 600 to 900 s ⁻¹ .

Japanese Patent Application Laid-Open No. 2012-200931 JP 2014-000320 A Japanese Patent Laid-Open No. 2006-001015 Japanese Patent Laying-Open No. 2015-217552

However, the conventional techniques described above have the following problems.
That is, in the technique of Patent Document 1, there is a problem that the capital investment increases in order to reduce the oxygen concentration in order to reduce the oxidative degradation products, and a more practical method for reducing the oxidative degradation products is required. It was.
In addition, the technique of Patent Document 2 does not prevent the occurrence of the main body itself, but blows the gas to the main body to physically exclude the main body, and the amount of the generated main body cannot be suppressed. In addition, this technique has a problem in that an increase in resin temperature cannot be suppressed when the amount of extrusion is increased, and the amount of generation of the resin increases.
Further, in the technique of Patent Document 3, the strand is stabilized by making the orifices at both ends of the die plate shorter than the orifice at the center of the die plate. However, the orifice diameter, the orifice length, the extrusion described in the examples are used. With the amount, the generation of the mains cannot be suppressed, and as described above, there is a problem that the amount of the mains generated increases when the extrusion amount is increased.
And in patent document 4, from the description of the Example, the shear rate of the orifice of the die part is 1000 s ⁻¹ (the orifice diameter is 3.6 mm, and the flow rate per hole is 18 kg / hr) Since the residence time of the resin composition at the orifice becomes long, the productivity of pellets is lowered, and the amount of generation of the tendency tends to increase.

  As mentioned above, the number of oxidation degradation products and the amount of scraping at the outlet of the orifice of the die plate are suppressed, the strand discharged from the outlet of the orifice of the die section is stabilized, the productivity of pellets is improved, and the yield of good pellets There was a need for technology that could improve

  It is an object of the present invention to produce high-quality thermoplastic resin composition pellets while reducing oxidation degradation products and suppressing the occurrence of scum at the orifice opening.

  As a result of intensive studies in order to solve the above-mentioned problems advantageously, the present inventor uses a compression-pulverized polyphenylene ether resin, and sets the orifice of the die plate to a predetermined mode and appropriately sets the residence time of the resin in the opening. By reducing the oxidation degradation, it is possible to effectively suppress the occurrence of scum at the orifice opening, and to stably prepare strands to obtain high-quality thermoplastic resin composition pellets. The present invention has been completed by finding out what can be done.

The gist of the present invention is as follows.
[1] A step of compression-pulverizing a polyphenylene ether resin to obtain a compression-pulverized polyphenylene ether resin;
Melt-kneading the compression-pulverized polyphenylene ether resin and the thermoplastic resin (A) to obtain a thermoplastic resin composition;
Using an extruder equipped with a die plate having a plurality of orifices having an inner diameter D of 3 to 8 mm and a length L of 0.3 to 2.0 times the inner diameter D, the orifice of the thermoplastic resin composition The average residence time T at 1 to 20 milliseconds, and obtaining a thermoplastic resin composition strand;
Pelletizing the thermoplastic resin composition strands to obtain thermoplastic resin composition pellets;
The manufacturing method of the thermoplastic resin composition pellet characterized by having.
[2] The method for producing a thermoplastic resin composition pellet according to [1], wherein the compressed pulverized polyphenylene ether has an average particle diameter of 1000 to 3000 μm and a ratio of the particle diameter of 106 μm or less is 20% by mass or less. .
[3] The heat according to [1] or [2], wherein the thermoplastic resin (A) is at least one selected from the group consisting of polystyrene resins, polyamide resins, polyolefin resins, and polyphenylene sulfide. A method for producing a plastic resin composition pellet.
[4] Of the plurality of orifices, the length Lo of the orifice located at the outermost end in the width direction of the die plate is closest to the center of the plurality of orifices in the width direction of the die plate. The method for producing a thermoplastic resin composition pellet according to any one of [1] to [3], which is 0.5 to 0.8 times the length Lc of the orifice positioned.
[5] Among the plurality of orifices, the inner diameter Do of the orifice located at the outermost end in the width direction of the die plate is located closest to the center of the plurality of orifices in the width direction of the die plate. The method for producing a thermoplastic resin composition pellet according to any one of [1] to [4], which is 1.05 to 1.3 times the inner diameter Dc of the orifice.
[6] The thermoplastic resin composition according to any one of [1] to [5], wherein the surface hardness of at least part of the surface of the die plate where the orifice opens and the inner surface of the orifice is 800 to 5000. Pellet manufacturing method.
[7] On the downstream side of the extruder, a cooling device, a pelletizer, a dewatering device, a pellet cooler, a pellet sorter, an external lubricant addition device, a pellet transport device, a metal sorter, a foreign matter sorter, a chip separator, The thermoplastic resin composition pellet according to any one of [1] to [6], further using at least one selected from the group consisting of an intermediate tank, a product tank, a metal detector, a dry air generator, and a dehydrator. Production method.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing an oxidation degradation thing, generation | occurrence | production of the scum at the opening part of an orifice can be suppressed, and a good quality thermoplastic resin composition pellet can be manufactured.

It is a figure shown about the outline | summary of an example after the melt-kneading process in the manufacturing method of the thermoplastic resin composition pellet of this embodiment. It is a figure shown about an example of the die | dye part with which the extruder used by the extrusion process in the manufacturing method of the thermoplastic resin composition pellet of this embodiment is mounted | worn. (A) is sectional drawing when a die part is cut | disconnected by the surface perpendicular | vertical to the bottom face, Specifically, it is sectional drawing of the die part by the surface along line II shown to (B), (B ) Is a cross-sectional view when the die portion is cut by a plane parallel to the bottom surface thereof, specifically, a cross-sectional view of the die plate by a plane along line II-II shown in FIG.

  Hereinafter, modes for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. And this invention can be deform | transformed suitably and implemented within the range of the summary.

  In the drawings, positional relationships such as up, down, left and right are based on the positional relationships shown in the drawings unless otherwise specified. In the drawings, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted. The dimensional ratio of the present embodiment is not limited to the illustrated dimensional ratio.

(Method for producing thermoplastic resin composition pellets)
The thermoplastic resin composition pellet manufacturing method of the present embodiment includes at least a step of compressing and pulverizing a polyphenylene ether resin to obtain a compressed pulverized polyphenylene ether resin (PPE compression pulverizing step), a compressed pulverized polyphenylene ether resin and a heat A process of obtaining a thermoplastic resin composition by melt-kneading the thermoplastic resin (A) (melt-kneading process), and using an extruder equipped with a die plate having a plurality of predetermined orifices, the thermoplastic resin composition The process of obtaining a thermoplastic resin composition strand from the process (extrusion process) and the process of pelletizing the thermoplastic resin composition strand to obtain a thermoplastic resin composition pellet (pelletizing process).
Moreover, in the manufacturing method of this embodiment, the process (cooling process) which cools the thermoplastic resin composition strand obtained by the extrusion process arbitrarily using a cooling device between an extrusion process and a pelletizing process arbitrarily. Optionally, after the pelletizing step, a step of post-processing the thermoplastic resin composition pellets (post-processing step) may be selected as appropriate.

  On the other hand, from the viewpoint of the apparatus to be used, in the manufacturing method of the present embodiment, on the downstream side of the extruder, a cooling device, a pelletizer, a dehydrating device, a pellet cooler, a pellet sorter, an external lubricant addition device, and pellet transport You may further use at least 1 chosen from an apparatus, a metal sorter, a foreign material sorter, a chip separator, an intermediate tank, a product tank, a metal detector, a dry air generator, and a dehydrator.

  Hereinafter, the “thermoplastic resin composition strand” may be simply referred to as “strand”, and the “thermoplastic resin composition pellet” may be simply referred to as “pellet”.

<PPE compression pulverization process>
The PPE compression pulverization step is a step of obtaining a compression pulverized polyphenylene ether resin by compressing and pulverizing the polyphenylene ether resin.

<< Polyphenylene ether resin >>
The polyphenylene ether resin used in the present embodiment is not limited to the following, but examples thereof include poly (2,6-dimethyl-1,4-phenylene ether) and poly (2-methyl-6-ethyl-1). , 4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether), poly (2,6-dichloro-1,4-phenylene ether), and the like. A polyphenylene ether copolymer such as a copolymer of dimethylphenol and other phenols (for example, 2,3,6-trimethylphenol or 2-methyl-6-butylphenol) is also included. A polyphenylene ether resin may be used individually by 1 type, and may be used in combination of 2 or more type. In particular, as the polyphenylene ether resin, poly (2,6-dimethyl-1,4-phenylene ether), a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol is preferable, and poly (2 , 6-dimethyl-1,4-phenylene ether) is more preferable.

  The polyphenylene ether resin used in the present embodiment can be prepared, for example, by preparing desired monomer components and polymerizing them in a polymerization tank according to a conventional method. The polymerization may be performed in the presence of a good solvent such as aromatic hydrocarbon. Alternatively, the polyphenylene ether resin used in the present embodiment may be a commercially available product.

  From the viewpoint of purity, the polyphenylene ether resin used in the present embodiment preferably contains a remaining good solvent such as an aromatic hydrocarbon as a binder component. The content of the good solvent in the polyphenylene ether resin is preferably 0.005 to 0.3% by mass, more preferably 0.005 to 0.25% by mass, and 0.01 to 0.1%. More preferably, it is mass%. Although depending on the temperature and linear pressure during compression, if the good solvent remaining in the polyphenylene ether resin is 0.005% by mass or more, the compression molding effect is sufficiently obtained, and 0.3% by mass or less If so, discoloration due to melting of the polyphenylene ether resin can be sufficiently suppressed.

The polyphenylene ether resin used in the present embodiment preferably has a reduced viscosity (unit: g / dl, measured in chloroform at 30 ° C.) of 0.10 to 0.70. When the reduced viscosity of the polyphenylene ether resin is 0.10 or more, the mechanical strength of the resulting thermoplastic resin composition pellets can be maintained well, and when it is 0.70 or less, melt kneading is achieved. The fluidity of time can be maintained. From the same viewpoint, the reduced viscosity of the polyphenylene ether resin used in the present embodiment is more preferably 0.20 or more, further preferably 0.30 or more, and 0.65 or less. More preferably, it is 0.60 or less.
The reduced viscosity is measured with a chloroform solvent, 30 ° C., and a 0.5 g / dl solution using an Ubbelohde viscometer.

The polyphenylene ether resin used in the PPE compression pulverization step is preferably one having an average particle diameter of less than 700 μm or a collection of fine particles having a particle diameter of less than 700 μm.
In addition, an average particle diameter shall point out the particle diameter of 50% of accumulation.

<< Compression of polyphenylene ether resin >>
In the PPE compression pulverization step, for example, the prepared polyphenylene ether resin is compressed at a temperature not higher than its glass transition temperature (Tg). When compressing, the temperature of the polyphenylene ether resin should not exceed Tg. The temperature at the time of compression is not particularly limited as long as the polyphenylene ether resin can be pressurized without exceeding Tg at the time of compression, and is preferably 20 ° C. to Tg or less, preferably about 20 to 170 ° C. More preferred. In addition, when the temperature at the time of compression exceeds Tg, the residual amine which may be contained in the polyphenylene ether resin is detached, and there is a possibility that the quality is deteriorated at the time of processing.

  Examples of the molding apparatus that can be used for the compression operation of the polyphenylene ether resin include compression molding machines such as a compression roll type and a tableting molding type. In particular, a polyphenylene ether resin having a low apparent specific gravity is passed between a pair of pressure rolls provided facing each other, and a plate-like polyphenylene ether resin obtained by compression is pulverized in a pulverization operation described later to obtain a desired It is preferable to use a roll type compression molding machine capable of adjusting the particle size.

When a plate-like polyphenylene ether resin is obtained by a roll type compression molding machine, the linear pressure (roll pressure / roll width) by the roll type compression molding machine is preferably 0.7 to 11 kN / cm. It is more preferably 0 to 8.0 kN / cm, and further preferably 1.5 to 7.0 kN / cm. When the linear pressure is less than 0.7 kN / cm, since the compression effect is small, the reduction of the void ratio inside the polyphenylene ether resin is insufficient, the apparent specific gravity is not sufficiently improved, and the compressed product is brittle. Fine powder is likely to be generated during pulverization. On the other hand, if the linear pressure is more than 11 kN / cm, the compressed product becomes too hard and pulverization is not easy, so the amount of fine powder increases.
In addition, it is preferable that the clearance gap (roll clearance) between rolls is about 1-3 mm, and it is preferable that the rotation speed of a roll is 2-20 rpm.

In the compression operation, the polyphenylene ether resin is compressed so that the bulk density of the compressed polyphenylene ether resin is preferably 0.70 to 1.0 g / cm ³ , more preferably 0.72 to 0.85 g / cm ^3. can do. In this regard, the polyphenylene ether resin to be subjected to the compression operation may be a heated one (for example, a polyphenylene ether resin immediately after polymerizing a desired monomer component and then dried) or a non-heated one ( For example, it may be a polyphenylene ether resin obtained by polymerizing a desired monomer component and then drying, or a certain amount of time, or a commercially available polyphenylene ether resin.
The bulk density of the polyphenylene ether resin can be expressed by (weight of polyphenylene ether resin) / (volume of polyphenylene ether resin).

  In the compression operation, an additive serving as a binder may be used as necessary. For example, the polyphenylene ether resin and the additive may be mixed in advance with a blender and then supplied to a compression molding machine. Examples of the additive include flame retardants such as phosphorus-based flame retardants and antioxidants.

The molding apparatus used in the compression operation is preferably maintained in an atmosphere having an oxygen concentration of 10% by volume or less. By controlling the oxygen concentration to 10% by volume or less, dust explosion can be prevented and oxygen attached to the surface of the polyphenylene ether resin during compression can be effectively removed. From the same viewpoint, the oxygen concentration inside the molding apparatus is more preferably 3% by volume or less, and further preferably 1% by volume or less.
As a method for lowering the oxygen concentration inside the molding apparatus, a method of supplying an inert gas (nitrogen, carbon dioxide, etc.) is generally cited.

<< Pulverization of polyphenylene ether resin >>
Subsequently, the compressed polyphenylene ether resin is pulverized to obtain a compressed pulverized polyphenylene ether resin. In this pulverization operation, a granulator may be used, whereby the particle size of the compression-pulverized polyphenylene ether resin can be adjusted.

  Examples of the pulverizer that can be used for the pulverization operation of the polyphenylene ether resin include a jaw crusher, a cone crusher, a flake crusher, a hammer mill, a feather mill, a ball mill, a high-speed rotating mill, and a jet mill.

  In the pulverization operation, the bulk density of the pulverized polyphenylene ether resin (compressed pulverized polyphenylene ether resin) is 0.35 to 0.70 g / cc, and the ratio of the particle size is 106 μm or less is preferably 20% by mass or less. You may adjust the rotor rotation speed and screen opening of a grinding | pulverization apparatus so that it may preferably become less than 15 mass%, More preferably, it may be less than 10 mass%.

  Moreover, it is preferable that the average particle diameter of the compression-pulverized polyphenylene ether resin obtained in the PPE compression-pulverization step is 1000 to 3000 μm. By ensuring that the average particle size of the compressed and pulverized polyphenylene ether resin is 1000 μm or more, it is possible to sufficiently secure the conveyance capability in the melt-kneading step and effectively suppress the temperature rise of the resin composition, When the thickness is 3000 μm or less, micromixability can be improved during the melt-kneading with the thermoplastic resin (A) described later, and higher-quality thermoplastic resin composition pellets can be obtained. From the same viewpoint, the average particle size of the compressed and pulverized polyphenylene ether resin is more preferably 1100 μm or more, further preferably 1200 μm or more, more preferably 2000 μm or less, and 1500 μm or less. Is more preferable.

  Furthermore, the compression-pulverized polyphenylene ether resin obtained in the PPE compression-pulverization step preferably has a ratio of particle size of 106 μm or less of 20% by mass or less. When the ratio of the particle size of 106 μm or less in the compression-pulverized polyphenylene ether resin is 20% by mass or less, sufficient transport capability in the melt-kneading process is ensured, and the temperature rise of the resin composition is effectively suppressed. be able to. From the same viewpoint, the compression-pulverized polyphenylene ether resin preferably has a particle size of 106 μm or less, more preferably less than 15% by mass, and even more preferably less than 10% by mass.

<Melting and kneading process>
The melt-kneading step is a step of obtaining a thermoplastic resin composition by melt-kneading the compression-pulverized polyphenylene ether resin obtained in the PPE compression-pulverization step and the thermoplastic resin (A). In the melt-kneading step, a phosphorus-based flame retardant, a powder filler, a fibrous filler, various additives, and the like can be further used as a material for melt-kneading as necessary.
Note that the melt-kneading step may be performed continuously or discontinuously with the PPE compression pulverization step described above. However, the melt-kneading step is usually performed discontinuously with the PPE compression-pulverization step described above, such as after the compression-pulverized polyphenylene ether resin obtained in the PPE compression-pulverization step is stored for a certain period of time. It is.

<< Thermoplastic resin (A) >>
Examples of the thermoplastic resin (A) used in the melt-kneading process of the present embodiment include general-purpose polystyrene (GPPS), high-impact polystyrene (HIPS), styrene / butadiene copolymer (styrene / butadiene block copolymer, hydrogen). Polystyrene resins such as styrene / butadiene block copolymers); styrene / acrylonitrile copolymers, styrene / acrylonitrile copolymers such as acrylonitrile / butadiene / styrene copolymers; 6 nylon, 66 nylon, 610 nylon, etc. Polyamide resin; Polyolefin resin such as linear low density polyethylene, low density polyethylene, high density polyethylene, polypropylene (homo, copolymer); polyphenylene sulfide; and the like. A thermoplastic resin (A) may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, the thermoplastic resin (A) is at least one selected from the group consisting of polystyrene-based resins, polyamide-based resins, polyolefin-based resins, and polyphenylene sulfide from the viewpoint of obtaining higher quality pellets. preferable.
In the present embodiment, the “thermoplastic resin (A)” does not include a polyphenylene ether resin.

  The styrene / butadiene copolymer that can be used as the thermoplastic resin (A) may be partially random or tapered. The styrene / butadiene copolymer preferably has a weight average molecular weight of 30,000 to 500,000, a styrene content of 25 to 70% by mass, and a butadiene content of 75 to 30. It is preferable that it is mass%.

<< Phosphorus flame retardant >>
In the melt-kneading step of the present embodiment, a phosphorus flame retardant can be further used as a material for melt-kneading from the viewpoint of further improving the flame retardancy. Examples of phosphorus flame retardants include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, tert-butylphenyl diphenyl phosphate, and bis- (tert-butylphenyl) phenyl. Aromatic phosphates such as phosphate, tris- (tert-butylphenyl) phosphate, isopropylphenyldiphenylphosphate, bis- (isopropylphenyl) diphenylphosphate, tris- (isopropylphenyl) phosphate; resorcinol bis-diphenylphosphate (RDP) Resorcinol bis-dixylenyl phosphate, bisphenol A bis-diphenyl phosphate, biphenyl biphenyl - condensed phosphate such as diphenyl phosphate; polyphosphazenes compounds. A phosphorus flame retardant may be used individually by 1 type, and may be used in combination of 2 or more type.
Moreover, in the melt-kneading process of this embodiment, it is preferable that the ratio which uses a phosphorus flame retardant is less than 30 mass%.

<< Powder filler >>
In the melt-kneading process of the present embodiment, a powder filler may be further used as a material for melt-kneading. Examples of the powder filler include potassium titanate whisker, magnesium sulfate whisker, aluminum borate whisker, calcium carbonate whisker, silicon carbide whisker, zinc oxide whisker, calcium silicate (wollastonite), mica, talc, glass flake, Examples include calcium carbonate, clay, kaolin, barium sulfate, silica, alumina, magnesium oxide, magnesium sulfate, and especially calcium silicate, mica, talc, glass flake, ground glass, titanium oxide, calcium carbonate, kaolin, silica Is preferred. A powder filler may be used individually by 1 type, and may be used in combination of 2 or more type. The size of the powder filler may be an average particle size of 0.01 to less than 500 μm, preferably 0.01 to 300 μm, and more preferably 0.1 μm or more and less than 106 μm.
Moreover, in the melt-kneading process of this embodiment, it is preferable that the ratio which uses a powder filler is less than 60 mass%.

<< Fibrous filler >>
In the melt-kneading step of this embodiment, a fibrous filler may be further used as a material for melt-kneading. Examples of the fibrous filler include glass fiber, carbon fiber, and metal fiber. A fibrous filler may be used individually by 1 type, and may be used in combination of 2 or more type. The size of the fibrous filler is preferably a fiber diameter of 5 to 50 μm and a fiber length of 1 to 5 mm.
Moreover, in the melt-kneading process of this embodiment, it is preferable that the ratio which uses a fibrous filler is less than 60 mass%.

<< carboxyl group-modified polymer >>
In the melt-kneading step of the present embodiment, as the above-mentioned polystyrene resin, a resin obtained by copolymerizing a monomer containing a carboxyl group (for example, citric acid, maleic anhydride, etc.) and a styrene monomer, or carboxyl Resin obtained by grafting a monomer containing a group with an extruder can be used, and a resin obtained by grafting a monomer containing a carboxyl group with an extruder can be used as the polyphenylene ether resin (hereinafter referred to as these). These resins are collectively referred to as “carboxyl-modified polymers”). However, in the melt-kneading step of the present embodiment, the ratio of using the carboxyl group-modified polymer is preferably less than 5% by mass.

<< Various additives >>
In the melt-kneading step of this embodiment, various additives can be further used as materials for melt-kneading. Examples of additives include liquid additives (silicon oil, hydrocarbon oil, water, etc.), powder filler dispersants (ethylene bisamide, calcium stearate, zinc stearate, stearic acid, etc.), olefin elastomers (ethylene, etc.)・ Propylene elastomer, ethylene octene elastomer), functional group imparting agents (maleic acid, fumaric acid, itaconic acid, maleic anhydride, malic acid, citric acid, etc.), various colorants, coloring additives (titanium oxide, etc.), Examples include ultraviolet absorbers, antistatic agents, stabilizers (zinc oxide, zinc sulfide, phosphorus-based, sulfur-based, hindered phenol-based, etc.).

<< Melting and Kneading >>
And in the melt-kneading process of this embodiment, a thermoplastic resin composition can be obtained by melt-kneading using the material mentioned above. The conditions for melt kneading may be appropriately determined according to the purpose and application. The melt-kneading can be carried out using an extruder, and examples of such an extruder include an extruder as described later with respect to the extrusion step. That is, if an extruder as will be described later is used, at least the melt-kneading step and the extrusion step can be carried out continuously.

<Extrusion process>
The extrusion step is a step of obtaining a strand from the thermoplastic resin composition obtained in the melt-kneading step using a predetermined extruder. In the extrusion process of the present embodiment, an extruder equipped with a die plate having a plurality of orifices having an inner diameter D of 3 to 8 mm and a length L of 0.3 to 2.0 times the inner diameter D is used. It is essential. Furthermore, in the extrusion process of this embodiment, it is important to obtain a strand by setting the average residence time T at the orifice of the melt-kneaded thermoplastic resin composition to 1 to 20 milliseconds. As a result, the temperature of the resin composition at the orifice opening of the die plate can be reduced, the generation of the resin at the orifice opening can be suppressed, and the thermoplastic resin composition strand can be stably prepared. In addition, it becomes possible to obtain thermoplastic resin composition pellets at a high yield rate.

As the above-mentioned extruder, as shown in FIG. 1, there is an extruder 1 that has a die part 2 and can continuously perform a melt-kneading process and an extrusion process collectively.
The extruder 1 is not particularly limited, and examples thereof include a multi-screw extruder such as a single screw extruder and a twin screw extruder. As a single screw extruder, for example, a single screw extruder manufactured by Buss (Konida series), a counter-rotating twin screw extruder, a co-rotating twin screw extruder ( Examples include ZSK series manufactured by Coperion, TEM series manufactured by Toshiba Machine Co., Ltd., and TEX series manufactured by Nippon Steel Works). As the extruder 1, there are high torque extruders such as the Mc Series, McPlus series, Mc18 series, COSION series, SS series, SX series, Nippon Steel Works α2 series, α3 series, manufactured by Coperion. preferable.
Although the specification and size of the extruder 1 are not particularly limited, the inner diameter (diameter) of the barrel is preferably 40 to 300 mm, and the effective barrel length is preferably 10 to 60 times the inner diameter of the barrel.
The barrel configuration of the extruder 1 is not particularly limited, and includes a plurality of barrels, and may form a solid conveyance zone, a melt conveyance zone, a kneading zone, etc. in a desired barrel. Further, a vent such as a vacuum vent or an atmospheric vent may be provided, and a top feeder, a side feeder, or a liquid addition device may be provided. As the length of each zone, when the length of the extruder (barrel effective length) is 100%, the length of the solid conveyance zone is 10 to 30%, and the length of the melt conveyance zone is 30 to 85. %, And the length of the kneading zone may be 5 to 40%.
Examples of screw elements used in the barrel include 2 or 3 kneading blocks (clockwise, counterclockwise, neutral, reverse feed), 2 or 3 flight screws (clockwise, counterclockwise), 1 Examples include a notch screw, a cut screw, a varistor ring, and the like, and may be used in appropriate combination.
Although it does not specifically limit as extrusion amount, For example, in a 58 mm diameter twin-screw extruder, it may be 300-1500 kg / hr, and may be 300-1500 rpm as the rotation speed of a screw.

  In an example of the extrusion process of the present embodiment, the molten thermoplastic resin composition is then made into a strand at the die portion 2 provided at the tip portion of the extruder 1.

  FIG. 2 shows an example of a die portion mounted on the extruder. FIG. 2A is a cross-sectional view when the die portion is cut along a plane perpendicular to the bottom surface, specifically, a cross-sectional view of the die portion taken along the line II shown in FIG. 2B is a cross-sectional view when the die portion is cut along a plane parallel to the bottom surface thereof, specifically, a cross section of the die plate by a plane along line II-II shown in FIG. FIG.

The die part 2 shown in FIG. 2 may have the same configuration except that the inclination angle (not shown) formed by the extending direction of the orifice and the axial direction of the extruder is different.
Specifically, in the die part 2 shown in FIG. 2, in the cross section of FIG. 2A, the inclination angle (not shown) formed by the extending direction of the orifice and the axial direction of the extruder is 0 to 60 °. Good.

  The die part 2 includes a die connection part 21, a screen changer part 22 for removing foreign substances contained in the molten thermoplastic resin composition by filtration, a manifold part 23, and a die plate part 24.

  The screen changer unit 22 may be equipped with a breaker plate to which a metal mesh having openings of # 20 to # 300 may be attached alone or in combination of two or more. The breaker plate may be equipped with a super plate capable of increasing the filtration area 1.5 to 2.0 times. Moreover, when the thermoplastic resin composition contains a reinforcing material such as a powder filler or a fibrous filler, the breaker plate may be removed.

The manifold portion 23 is provided with a resin composition flow path therein, and the width of the resin composition flow path (the length in the width direction of the die portion 2) is directed toward the tip of the die portion 2. (From the upstream side in the axial direction of the extruder toward the downstream side). Specifically, in FIG. 2B, the line defining the flow path is symmetrical on both sides with respect to the width direction of the die part 2, and from the position where the width of the flow path starts to gradually increase to the tip of the die part 2. It extends in a straight line.
In addition, the manifold part 23 of this embodiment is not limited to what is shown in FIG. 2 (B), The line which defines a flow path may be asymmetrical about both sides in the width direction of the die part 2. Although it may extend in a curved line, it is preferably symmetrical and preferably linear from the viewpoint of productivity and the like.

Here, as shown in FIG. 2B, in the cross-sectional view when the die portion 2 is cut along a plane parallel to the bottom surface, a line defining the flow path in a portion where the width of the flow path is constant, The angle θ1 formed with the line defining the flow path in the portion where the width of the flow path gradually increases is preferably 20 to 70 °, and more preferably 25 to 65 °.
Note that the angle θ1 is the smaller of the angles formed by the line defining the flow path in the portion where the width of the flow path is constant and the line defining the flow path in the portion where the width of the flow path gradually increases. The angle.
If the angle θ1 is set to 20 ° or more, the number of orifices provided in the die plate portion 24 can be increased (the production amount is increased). If the angle θ1 exceeds 70 °, the width of the die portion 2 is increased. At both ends, the fluidity of the molten resin composition is lowered, and a difference in flow velocity occurs between the strands at the center of the die plate 24 and the strands at both ends, and the preparation of the strands at both ends becomes unstable. Cheap.
The angle θ1 may be determined in a cross section passing through the center of the flow path. In addition, when all or part of the lines defining the flow path are curved, the angle θ1 may be determined after capturing the lines as average straight lines.

The die plate part 24 is for making a molten thermoplastic resin composition into a strand, and has a plurality of orifices 24o that are cylindrical through holes.
The number of orifices is preferably 10 or more, more preferably 12 or more, and more preferably 15 or more.
The inner diameter D of the orifice is 3.0 to 8.0 mm, preferably 3.5 to 8.0 mm, and more preferably 4.0 to 7.0 mm. When the inner diameter D is smaller than 3.0 mm, the die pressure tends to increase, and the temperature of the resin composition becomes high. When the inner diameter D is larger than 8.0 mm, the die pressure is excessively lowered, and the stability of the strand is lowered.
The length L of the orifice is 0.3 to 2.0 times the inner diameter D of the orifice, preferably 0.4 to 1.5 times, more preferably 0.5 to 1.0 times. is there. If the ratio (L / D) of the orifice length L to the inner diameter D of the orifice is smaller than 0.3, the die pressure is too low and the strand may become unstable. If L / D is greater than 2.0, the die pressure will increase too much, the temperature of the resin composition will increase, and the amount of the resin will increase, and the friction between the molten resin composition and the inner wall of the orifice 24o will increase, resulting in a further increase in the resin. There is a fear.

  In particular, when operating with an extruder with a small scale and an increased amount of extrusion, it is necessary to increase the number of orifices and lower the die pressure. If the number of orifices is increased, the width of the flow path of the manifold portion 23 needs to be increased. Furthermore, when the width of the flow path of the manifold portion 23 is widened, the flow rate of the resin flowing at both ends of the manifold portion 23 becomes extremely slow, and the stability of the strands at both ends tends to deteriorate.

In the extrusion process of the present embodiment, it is important that the average residence time T at the orifice of the melt-kneaded thermoplastic resin composition is 1 to 20 milliseconds. The average residence time T is preferably 2 to 15 milliseconds, and more preferably 3 to 15 milliseconds.
The average residence time T can be calculated by the following formula.
Average residence time T = Internal volume V / volume flow rate Q of all orifices
When T is shorter than 1 millisecond, the die pressure decreases and the strand becomes unstable. When T exceeds 20 milliseconds, the die pressure increases, the resin temperature rises, and the amount of sag increases.

  In the extrusion process of this embodiment, the flow rate of the resin composition per orifice 24o is preferably 20 to 120 kg / hr, more preferably 25 to 100 kg / hr, and more preferably 30 to 100 kg. / Hr. If the flow rate is less than 20 kg / hr, the residence time may be too long, and if it exceeds 120 kg / hr, the residence time may be too short.

In the present embodiment, the length Lo (see FIG. 2B) of the plurality of orifices located at the outermost end in the width direction of the die plate is the same as the length of the die plate in the width direction of the die plate. It is preferably 0.5 to 0.8 times, more preferably 0.5 to 0.7 times the length Lc of the orifice located closest to the center (see FIG. 2B).
When the melt viscosity of the thermoplastic resin composition is high, or when the number of orifices exceeds 10, the flow rate of the resin composition located at both ends in the width direction of the manifold tends to be slow. Here, if Lo / Lc is less than 0.5 times, the die pressure at both ends may decrease too much, and the strand may become unstable. If Lo / Lc is more than 0.8 times, the flow velocity at both ends is slow. Become.
At this time, only the lengths of the two orifices located at the outermost ends in the width direction may be shorter than the lengths of the orifices located closest to the center in the width direction. The taper may be gradually decreased from the position closest to the center in the width direction to the position of the outermost end in the width direction, or may be shortened stepwise.

Among the plurality of orifices, the inner diameter Do (see FIG. 2B) of the orifice located at the outermost end in the width direction of the die plate is located closest to the center in the width direction of the die plate among the plurality of orifices. The inner diameter Dc (refer to FIG. 2B) of the orifice is preferably 1.05 to 1.3 times, more preferably 1.1 to 1.3 times.
Even if Do / Dc is set to a range of 1.05 to 1.3 times, the same effect as when the range of Lo / Lc is determined has the effect of stabilizing the strand and increasing the flow velocity at both ends.

Here, the surface hardness of at least part of the surface of the die plate where the orifice opens and the inner surface of the orifice is preferably 800 to 5000, and more preferably 800 to 4000.
In addition, surface hardness means HV hardness and HV hardness can be measured based on JISZ2244.
Usually, SUS or SKD is used as the material of the die plate, and even when quenching them, the surface hardness of the surface of the die plate often remains at about 50. With this degree of hardness, the surface of the die plate where the orifice opens and the inner surface of the orifice are easily scratched. For example, when the strand is cut with a metal blade, it is made of a soft material such as brass or copper. Even when the blade is used, the orifice opening and the like are easily damaged, which causes the occurrence of cracks. In addition, with the above hardness, wear tends to occur on the inner surface of the orifice due to use for a long time, and this wear causes the occurrence of cracks.

In view of the above circumstances, in order to increase the hardness of the surface of the die plate, it is preferable to perform a surface treatment on all or part of the surface of the die plate including the surface where the orifice of the die plate opens and the inner surface of the orifice. Examples of the surface treatment include nitriding treatment and metal vapor deposition treatment. By performing the surface treatment, irregularities can be created in the structure of the orifice inner surface and the orifice outlet surface, the contact between the molten resin composition and the orifice inner surface becomes point contact, and the contact area is reduced, reducing the occurrence of a mean. By carrying out the surface treatment, the affinity with the molten resin composition is lowered, and the occurrence of the mains can be reduced.
As the nitriding treatment, known nitriding treatment or New Kanak treatment of Kanak (Japan) is preferable, and New Kanak treatment is particularly preferable. When New Kanak processing is performed, the surface hardness of the surface of the die plate becomes about 1000, and the occurrence of mess can be suppressed.
Examples of the metal vapor deposition treatment include a chemical vapor deposition film forming method and a physical vapor deposition film forming method. Here, examples of the coating material include titanium carbide, titanium carbonitride, chromium carbide, titanium nitride, titanium nitride aluminum, and the like, and titanium nitride aluminum is preferable.
When titanium nitride aluminum is vapor-deposited by the Physical Vapor Deposition film formation method, the surface hardness of the surface of the die plate increases to about 3500, and the surface is hardly damaged.

<Cooling process>
The cooling step is an arbitrary step of cooling the thermoplastic resin composition strand obtained in the extrusion step using the cooling device 3. As the cooling device 3, a cooling water storage tank (strand cooling tank 3 a in FIG. 1), an inclination angle θ 2 formed between the extending direction and a horizontal plane is set to 30 to 85 °, and from one end to the other end. Examples include a flow path (strand guide, not shown) in which cooling water is flowed.
The inclination angle θ2 refers to the smaller angle of the angles formed between the extending direction of the flow path and the horizontal plane.

  As the cooling water used for the cooling device 3, pure water, ion exchange water, industrial water, cooling water circulating in the cooling tower, or the like may be used.

The strand cooling tank 3a is not particularly limited as long as the cooling water can be retained for a predetermined time, and the cooling water may be replaced intermittently or continuously.
Usually, the cooling water is supplied on the downstream side of the strand cooling tank 3a, discharged on the upstream side, and cooled countercurrently to the discharged strand.
In the strand cooling tank 3a, it is preferable to use a plurality of strand guide rollers in order to stabilize the strands. The strand guide roller is operated with fixed rotation when the strand approaches the inside.
Moreover, in order to remove the water adhering to the surface of the strand, an air wiper having a function of blowing air or a plastic fiber brush may be used for the strand cooling tank 3a.

  The distance L1 from the opening of the orifice to the cooling device (see FIG. 1), that is, the distance from the position where the strand is discharged to the outside of the die plate to the position where the strand reaches the water of the cooling device, the smaller the strand However, it may be 100 to 400 mm.

<Pelletization process>
The pelletizing step is a step of pelletizing (cutting) the thermoplastic resin composition strand after the extrusion step or optional cooling step to obtain thermoplastic resin composition pellets. In the pelletizing process, for example, a thermoplastic resin composition pellet having a cylindrical shape can be obtained by cutting the thermoplastic resin composition strand appropriately cooled in the cooling process to an appropriate length with a pelletizer.

  Examples of the pelletizer 4 that can be used in the pelletizing process include a pelletizer having a rotary blade width of 200 to 500 mm and a take-up speed of 60 to 300 m / min. Here, the pelletizer 4 includes a dry pelletizer and a wet pelletizer. When the strand cooling tank 3a is used in the cooling process, a dry pelletizer may be used, and air may be blown to the rotary blade or the fixed blade to prevent generation of chips. Further, the wet pelletizer can simultaneously pelletize the strand and the cooling water through the strand guide.

The pellets obtained by pelletizer 4 are preferably at least 95%, more preferably at least 96%, more preferably at least 97%, preferably having an outer diameter of 2-4 mm and a length of 2-4 mm. More preferably, the outer diameter is 2.2 to 3.8 mm and the length is 2.2 to 3.8 mm, and more preferably, the outer diameter is 2.5 to 3.5 mm and the length is 2.5 to It is 3.5 mm.
When a wet pelletizer is used as the pelletizer 4, water adheres to the surface of the pellets, and therefore a dehydrator for taking the water may be used. The dehydrating apparatus may be a centrifugal separation system or a drying system.

<Post-processing process>
A post-processing process is an arbitrary process which can select and implement various operations as shown below, for example.
Hereinafter, using FIG. 1, downstream of the pelletizer, pellet cooler, pellet sorter, external lubricant addition device, pellet transport device, metal sorter, foreign matter sorter, chip separator, intermediate tank, product tank, An example of the manufacturing method of the present embodiment that can be implemented with a metal detector, a dry air generator, and a dehydrator in this order will be described in detail.

In this embodiment, following the pelletizing process, the thermoplastic resin composition pellets obtained in the pelletizing process are cooled using the pellet cooler 5 (see FIG. 1).
In the pelletizer 4, the strand is cut at 120 to 150 ° C. to prevent generation of chips and moisture absorption of the pellet, and the pellet is heated to a high temperature. For this reason, the pellets may be discolored. In addition, when hygroscopic resin is used as a raw material for pellets, an aluminum bag internally coated with polyethylene resin may be used as a packaging bag. Shrink and stiffen the bag. Therefore, when the bag is loaded on the pallet, there is a possibility that a trouble that falls during transportation may occur. Furthermore, when the pellet is hot, a thin skin called floss may be formed when the pellet collides with the inner wall of the pneumatic piping. For this reason, it is preferable to cool the pellet temperature to about 40 to 70 ° C. using the pellet cooler 5. Here, as the pellet cooler 5, there are a fluidized bed type and a type in which the pellet is moved to a punching plate and cooled with a cooling gas from the bottom side. For example, an air cooling type manufactured by Tanaka Co., Ltd. It is preferable to use a pellet cooler ASC series.

Thereafter, in the present embodiment, the cooled thermoplastic resin composition pellets are passed through a pellet sorter 6 (see FIG. 1).
The pellet sorter 6 removes pellets pelletized by the pelletizer 4 such as pellets longer than 4 mm, twin pellets formed by fusing strands, chips from the pellets, and the like.

In the present embodiment, an external lubricant is given to the selected thermoplastic resin composition pellets using the external lubricant addition device 7 (see FIG. 1).
The external lubricant addition device 7 is a device that attaches the external lubricant to the pellet surface, and includes an external lubricant addition supply device and / or a mixer that uniformly mixes the external lubricant and pellets. Since the external lubricant is a powder-based additive, if the added amount exceeds 0.05 parts by mass, it is easy to separate from the pellets, so using the oil addition device, first, mix the oil and pellets, then An external lubricant may be mixed.

In the present embodiment, the thermoplastic resin composition pellets to which the external lubricant has been applied are further transported using the pellet transport device 8 (see FIG. 1).
The pellet conveying device 8 includes a pipe for conveying the pellet and a gas blower for sending the pellet. The gas blower may be either a pressurized blower that blows air from the upstream side or a suction blower that sucks air from the downstream side. Since the pellets collide and wear at the bent portion of the piping, in particular, the piping is preferably subjected to a wear resistance treatment such as ceramic treatment or nitriding treatment (New Kanak treatment by Kanak).

Next, in the present embodiment, the conveyed thermoplastic resin composition pellets are passed through a metal sorter 9 (see FIG. 1).
The metal sorter 9 is an apparatus used when removing metal fragments having a diameter or length of 0.1 mm or more contained in a pellet. Since the pellet may contain small metal pieces or the like contained in the raw material, it is preferable to pass the pellet through the metal sorter 9 when the pellet is used for an electronic component.

Moreover, in this embodiment, a thermoplastic resin composition pellet is passed through the foreign material sorter 10 (FIG. 1).
The foreign matter sorter 10 removes pellets that are generated in the extruder and contain foreign matters that cannot be filtered by a metal mesh attached to the breaker plate of the screen changer unit 22 or pellets with shards. It is a device used in cases. As the foreign matter sorter 10, there are sensors that detect foreign matter on the front and back surfaces of the pellet flow. However, when only this is used, the removal rate of foreign matter is relatively low. Therefore, by using a foreign matter sorter with a total of four sensors, two front and rear and two left and right, or by using two foreign matter sorters with only two sensors as described above, The removal rate can be further improved.

And in this embodiment, a thermoplastic resin composition pellet is passed through the chip separator 11 (refer FIG. 1).
The chip separator 11 can be provided between the pelletizer 4 and the product tank 13. Chips are floss generated in pellet fragments of 1 mm or less and piping for conveying pellets. The chip separator 11 may be a system that separates a cyclone type having a small particle diameter, or may be an apparatus that ionizes chips. In particular, the chip separator 11 is of a cyclone type and is preferably provided on the product tank 13.

Here, the obtained thermoplastic resin composition pellets may be stored at one end in an optionally provided intermediate tank 12 (not shown), but in this embodiment, the pellets are stored in a product tank 13 (described later). ).
The intermediate tank 12 may be used when making the product after confirming the size and physical properties of the initial pellets that have been manufactured by operating each device.
The product tank 13 is a device for storing pellets. The product tank 13 needs a volume that can be stored for about 1 to 72 hours. Further, the intermediate tank 12 and / or the product tank 13 may include a pellet mixing device such as a mechanical mixer or a gas circulation mixer in order to make the pellets uniform.

And in this embodiment, the metal detector 14 is applied to a thermoplastic resin composition pellet.
The metal detector 14 is composed of, for example, 3 to 5 rows of several 5,000 to 15000 Gauss magnet bars arranged in a row. And by attaching the metal detector 14 to the outlet of the product tank 13, it is possible to detect pellets containing metal pieces.

Moreover, in this embodiment, you may give dry air to the thermoplastic resin composition pellet using the dry air generator 15. FIG.
For example, when the thermoplastic resin composition pellet contains a hygroscopic resin such as a polyamide-based resin and the atmosphere around the pellet is 40 ° C. or lower, the pellet may absorb moisture in the atmosphere, and the dry air generator 15 Can be used to deal with such a situation. The dry air generator 15 is an apparatus that generates dry air having a dew point of −40 ° C. and an absolute humidity of 0.119 g / m ³ , for example.

<Uses of manufactured thermoplastic resin composition pellets>
The thermoplastic resin composition pellets produced by the production method of the present embodiment can be suitably used for electric / electronic parts, OA parts, automobile parts and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to the following Example at all.

(Preparation of PPE1 (compression pulverized polyphenylene ether resin))
Using a Hosokawa micron production grain device (device name: CS-75, diameter: 400 mm, width: 120 mm), PPE3, which will be described later, under conditions of an oxygen concentration of 1% by volume, a roll clearance of 1.5 mm, a roll rotation speed of 7 rpm, and a linear pressure Compression was performed under conditions of 6 kN / cm to obtain a plate-like polyphenylene ether resin. Next, this plate-like polyphenylene ether resin was pulverized (sized) using a flake crusher (device name: FC-200) manufactured by Hosokawa Micron and a φ3 mm screen to obtain PPE1 which is a compression pulverized polyphenylene ether resin.

(Preparation of PPE2 (compression pulverized polyphenylene ether resin))
In the preparation of PPE1, except that the linear pressure was 3 kN / cm, the same conditions as in the preparation of PPE1 were used, and PPE2 which was a compression-pulverized polyphenylene ether resin was obtained.

(Preparation of PPE3 (uncompressed pulverized polyphenylene ether resin))
A polyphenylene ether resin (manufactured by Asahi Kasei Plastics Singapore, S201A) was prepared, and this was designated as PPE3 (uncompressed and pulverized polyphenylene ether resin).

  The following properties of PPE1 to PPE3 were determined according to the following method.

<Average particle size>
According to the screening test method of JIS Z 8815, sieves with mesh openings of 2360, 1700, 1180, 850, 600, 425, 300, 212, 150, 106, and 75 μm are arranged vertically, and the tray is at the bottom. The sieve was fixed by placing 100 g of the sample, and then shaken with a shaker to measure the weight of the particles remaining on each sieve. The particle size of the sample remaining on the sieve having a mesh opening of 2360 μm is a simple average value of 3000 μm and 2360 μm, the particle size of the sample remaining at 1700 μm is a simple average value of 2360 and 1700, and the sample particle size of the bottom tray Is 37.5 μm, which is half of 75 μm, illustrating the relationship between the sieve opening diameter and the amount of particles (% by mass), and the value of cumulative 50% is taken as the average particle size. The results are shown in Table 1.

<Proportion of particle size of 106 μm or less>
The ratio of the particles that passed through the sieve having an opening of 106 μm was determined by weight ratio by the vibration of each sieve by the shaker. The results are shown in Table 1.

<Bulk density>
The bulk density (relaxation) was measured according to JIS K5101. The results are shown in Table 1.

<Reduced viscosity>
Using an Ubbelohde viscometer, the reduced viscosity (g / dl) was measured with a chloroform solvent, 30 ° C., and a 0.5 g / dl solution. The results are shown in Table 1.

(Configuration of extruder and downstream apparatus)
The apparatus configuration as shown in FIG. 1 was adopted, and the same direction rotating twin screw extruder (TEM58SX 12 barrel manufactured by Toshiba Machine Co., Ltd.) was used as the extruder.
And the barrel structure of Examples 1-11 and Comparative Examples 1-5 and the conditions of each apparatus were as follows.
Barrel 1: First supply port (top feed barrel, weight-type feeder A, weight-type feeder B, oxygen concentration 3.0% by volume of the first supply port)
Barrel 2: Closed barrel Barrel 3: Closed barrel Barrel 4: Closed barrel Barrel 5: Second supply port (side feed (liquid addition) barrel)
Barrel 6: Closed barrel Barrel 7: Closed barrel (first kneading zone)
Barrel 8: Third supply port (side feed barrel)
Barrel 9: Closed barrel (second kneading zone)
Barrel 10: Vacuum vent Barrel 11: Closed barrel Barrel 12: Closed barrel Barrel set temperature: 280 ° C, die set temperature: 280 ° C.

Screen changer: Equipped with a breaker plate to which a metal mesh can be attached Manifold: Manifold angle θ1: 60 °
Die plate: The conditions were changed according to each example and comparative example.

  Strand cooling tank: A tank of width: 600 mm × length: 6000 mm was used. Cooling water temperature: 40 ° C. ± 3 ° C., water depth: 100 mm, and four strand guide rollers were installed. The strand guide roller was installed at least at a point where the strand entered water, and was a fixed type that did not rotate around the axis so that the strands at both ends would not come to the center. The distance L1 from the orifice opening to the cooling device (vertical distance between the orifice outlet and the liquid surface) was 120 mm. The length of the portion of the strand immersed in the cooling water was 2000 mm, and water adhering to the surface of the strand after immersion was removed using an air wiper.

Pelletizer: A rotary blade having a width of 300 mm was used. The target was a cylindrical pellet of length 3 mm × diameter 3 mm. The surface temperature of the strand at the inlet of the pelletizer was 140 ° C. The take-up speed was 100 m / min.
Pellet cooler: outlet temperature 50 ° C
Pellet sorter: Vibrating sieve was used. Long pellets, continuous (twin) pellets, and chips (small particle size pellets) were excluded.
External lubricant additive device: 0.03 parts by mass of ethylene bisamide is added to the pellet surface. Pellet conveying device: push-in type newer, air flow: 30 m ³ / hr
Metal sorter: High-sensitivity sorter made by Daika Corporation Direster Foreign matter sorter: Foreign matter sorter made by Kubota Corporation PLATON II
Chip separator: Zeno filter made by Kawata Co., Ltd. Intermediate tank: Not used Product tank: Capacity: 3m ³
Metal detector: 13000 Gauss magnets at the outlet of the product tank, 3 in 1 row.
The bagging was performed using a 25 kg bag.

(Measurement and evaluation method)
Regarding the production of the thermoplastic resin composition pellets in each Example / Comparative Example, the following measurement / evaluation was performed.

(0) Average residence time T
The density of the resin composition was 1.1 g / cm ^{3 in} Examples 1 to 8, Comparative Examples 1 to 5, 1.3 g / cm ³ in Example 9, 1.36 g / cm ³ in Example 10, and Examples 11, 1.51 g / cm ^3, example 12, Comparative example 6 in 1.1 g / cm ^3, example 13, and 0.95 g / cm ³ in Comparative example 7, the internal volume V of the volumetric flow rate Q of all the orifices The value divided by the value was defined as the average residence time T (milliseconds).

(1) Temperature measurement of the resin composition In the production of the thermoplastic resin composition pellets, a thermometer (on the strand discharged from the opening of the tenth orifice from the right as viewed in the direction from the die plate toward the barrel 1) The tip of the sensor of Handy Type Thermometer HD-1100 manufactured by Anritsu Keiki Co., Ltd. was inserted to measure the temperature (° C.) of the resin composition.

(2) Pressure measurement in die part In manufacture of a thermoplastic resin composition pellet, the pressure (MPa) in the die part was measured using a die pressure gauge (CZ-200P manufactured by Rika Kogyo Co., Ltd.) installed at the upper part of the manifold part. It was measured.

(3) Evaluation of Number of Oxidized Degraded Substances Evaluation of the number of oxidized deteriorated substances is performed by compressing and molding a thermoplastic resin composition pellet at 250 ° C. using a press die, thereby obtaining 5 flat plates having a diameter of 180 mm and a thickness of 1 mm. A sheet was produced. The number of oxidation deterioration products was evaluated by counting the number of black spots formed on the surface of the flat plate as oxidation deterioration products. Specifically, the front and back surfaces of five flat plates were visually observed using a 10 × magnifying glass, and a black spot having a maximum diameter of less than 200 μm was assigned 1 point, and a black spot having a maximum diameter of 200 μm or more was assigned 3 points.

(4) Evaluation of the level of generated amount of scallops In the manufacture of thermoplastic resin composition pellets, the size of the sag generated at the orifice opening (strand discharge port) of the die plate in 10 minutes after the strands started to be discharged It measured using. The determination was performed according to the following criteria.
1: Meani length of 1 mm or less.
2: Meani length of 3 mm or less.
3: Meani length of 5 mm or less.
4: Meani length of 7 mm or less.
5: Meani length 10 mm or less.
6: Meani length 15 mm or less.
7: Meani length more than 15 mm.

(5) Evaluation of Strand Stability In the production of the thermoplastic resin composition pellets, the state of the strand 20 minutes after the strand started to be discharged was observed and evaluated according to the following criteria. The smaller the criterion number, the more stable the strands and the better the final pellets.
<Judgment criteria (judgment point: strand stability)>
1: The total number of strands is neither strand curl nor strand breakage.
2: The state where only one end of the strand or one strand curls but cannot be cut.
3: A state in which several strands in both ends of the strand curl but cannot be cut.
4: A state in which one to several strands in both ends of the strand are curled and cut.
5: State in which strands are frequently cut.
The strand curl means that the strand is twisted. The strand break means that the strand breaks and the strand cannot be pulled.

Example 1
Barrel 1 and barrel 2 use a single screw that conveys powder raw material at a high rate, barrels 3 to 5 use a double screw, barrel 7 has a first kneading zone, and barrel 8 has a third supply port. And a second kneading zone was provided in the barrel 9, and deaeration was performed at −0.09 MPa by a vacuum vent provided in the barrel 10.
As the screw configuration of the first kneading zone, a clockwise kneading block, a neutral kneading block, and a screw having a small compression effect such as a clockwise notched two-thread screw were appropriately combined. Further, the screw configuration of the second kneading zone uses at least one screw having a high compression effect such as a counterclockwise kneading block, a counterclockwise screw, or a counterclockwise single notch screw as the screw of the first kneading zone. Combined.

Further, as the die plate, the die plate having the configuration shown in FIG. 2 is used, and the orifice inner diameter D = 4.0 mm, the orifice length L = 6.0 mm, the number of orifice rows: 1, and the number per orifice row Number of orifices: 25. A metal mesh was attached to the breaker plate of the screen changer in the configuration of (upstream side) # 20 / # 40 / # 80 / # 20 (downstream side) (# 20: No. 20 metal mesh).
And the extrusion rate of the extruder was set to 1000 kg / hr, and the screw rotation speed was set to 840 rpm.

65 parts by mass of PPE 1 was charged into the weight feeder A of the extruder and supplied to the first supply port of the barrel 1. Further, 4 parts by mass of high impact polystyrene (HIPS) (product name: CT60) as a thermoplastic resin (A), 3 parts by mass of general purpose polystyrene (GPPS) (product name: PS Japan, product name: 685) 1 part by weight of polyethylene (manufactured by Asahi Kasei Chemicals Corporation, product name: M1804), and 4 parts by weight of hydrogenated styrene-ethylene block copolymer (SEBS) (manufactured by Kraton Polymers (USA), product name: G1651 And 12.6 parts by mass of a mixture obtained by mixing 0.6 parts by mass of a stabilizer (Irganox 1010 / Adekastab PEP36 = 1: 2) with a tumbler. And supplied to the first supply port of the barrel 1.
12 parts by mass of a flame retardant (manufactured by Daihachi Chemical Co., Ltd., product name: CR731) was supplied to the second supply port through a liquid addition type nozzle through a liquid addition injection nozzle attached to the barrel 5.
13 parts by mass of high impact polystyrene (HIPS) (manufactured by Petrochemical Co., Ltd., product name: CT60) was supplied to the third supply port of the barrel 8.
And in the 1st kneading zone provided in the barrel 7, after mixing the raw material supplied from the 1st supply port and the flame retardant supplied from the 2nd supply port, HIPS is supplied from the 3rd supply port of the barrel 8. And completely melted in the second kneading zone provided in the barrel 9 to obtain a thermoplastic resin composition. Subsequently, the thermoplastic resin composition pellets were manufactured through steps such as making the molten thermoplastic resin composition into a strand with a die plate provided at the tip of the extruder and cutting with a pelletizer.

As a result, in Example 1, the pressure in the die part and the temperature of the resin composition were good, the amount of oxidative degradation and scum generation was small, and the strand stability was also good.
The detailed conditions and evaluation results in Example 1 and each example described below are summarized in Table 2.

(Comparative Example 1)
The same operation as in Example 1 was performed except that PPE1 was changed to PPE3. As a result, compared to Example 1, the number of oxidized degradation products and the amount of generated scum increased.

(Example 2)
The same operation as in Example 1 was performed except that PPE1 was changed to PPE2. As a result, as in Example 1, the pressure in the die part and the temperature of the resin composition were good, the amount of oxidation degradation products and scum generation were small, and the strand stability was also good.

(Comparative Example 2)
Implemented in the same manner as in Example 1 except that the extrusion rate of the extruder was set to 250 kg / hr, and the screw rotation speed was set to 210 rpm so that the ratio of extrusion volume / rotation speed was the same as in Example 1. did. As a result, the average residence time T became longer (30 milliseconds), the number of oxidative degradation products and the amount of scum generation increased, and strand breakage increased.

(Comparative Example 3)
The same operation as in Example 1 was performed except that the length L of the orifice was 10.0 mm (L / D = 2.5). As a result, the number of oxidative degradation products and the amount of spears increased, and strand breakage increased.

(Comparative Example 4)
The same operation as in Example 1 was performed except that the length L of the orifice was 1.0 mm (L / D = 0.25). As a result, the rectifying effect at the orifice disappeared and the strand breakage occurred everywhere.

(Comparative Example 5)
The same procedure as in Example 1 was performed except that the inner diameter D of the orifice was 2.5 mm and the length L of the orifice was 3.8 mm. As a result, the pressure in the die portion increased, the temperature of the resin composition also increased, the number of oxidized deterioration products and the amount of generated scum increased, and the strands were broken.

(Example 3)
The same operation as in Example 1 was performed except that the length L of the orifice was 4.0 mm (L / D = 1.0). As a result, as in Example 1, the pressure in the die part and the temperature of the resin composition were good, the amount of oxidation degradation products and scum generation were small, and the strand stability was also good.

(Example 4)
It implemented similarly to Example 3 except having changed the supply amount of PPE1 into 50 mass parts, and having changed the supply amount of HIPS from a 3rd supply port into 28 mass parts. As a result, as in Example 3, the pressure at the die part and the temperature of the resin composition were good, the amount of oxidation degradation products and scum generation were small, and the strand stability was also good.

(Example 5)
The same procedure as in Example 3 was performed except that the surface of the die plate (the surface where the orifice of the die plate opens and the inner surface of the orifice) was subjected to New Kanak treatment and the surface hardness (HV hardness) was set to 1000. As a result, the amount of generated spears was smaller than that in Example 3, the number of oxidative degradation products was small, and the strand stability was also good.

(Example 6)
Except that the surface of the die plate (the surface where the orifice of the die plate opens and the inner surface of the orifice) was subjected to titanium nitride aluminum (TiAlN) vapor deposition and the surface hardness (HV hardness) was set to 3500, the same as in Example 3. Carried out. As a result, the amount of generated spears was smaller than that in Example 3, the number of oxidative degradation products was small, and the strand stability was also good.

(Example 7)
Of the 25 orifices of the die plate, the length L (Lc) of the 15 orifices in the center is 4.0 mm, and the outer 5 sides are located outside the 15 in the width direction of the die plate. The length L of each orifice is gradually reduced by 0.3 mm step by step, and the length Lo of the outermost orifice is 2.5 mm (Lo / Lc = 2.5 / 4.0 = 0.625). The same operation as in Example 3 was carried out except that. As a result, the strand stability was improved as compared with Example 3.

(Example 8)
Out of the 25 orifices of the die plate, the inner diameter D (Dc) of 15 orifices in the center is 4.0 mm, and 5 outsides located outside the 15 in the width direction of the die plate. The inner diameter D of the orifice was gradually increased by 0.1 mm stepwise, and the inner diameter Do of the outermost orifice was 4.5 mm (Do / Dc = 4.5 / 4.0 = 1.125). Except for this, the same procedure as in Example 3 was performed. As a result, the strand stability was improved as compared with Example 3.

Example 9
Remove the metal mesh from the breaker plate of the screen changer, change the supply amount of PPE1 to 50 parts by mass, change the supply amount of HIPS from the third supply port to 8 parts by mass, and 20 parts by mass of glass fiber (Nittobo) The product was manufactured in the same manner as in Example 3 except that the product name: CSF-3PE-293) was further supplied from the third supply port. As a result, the pressure at the die part and the temperature of the resin composition were good, the amount of oxidized deterioration and the amount of scum were small, and the strand stability was also good.

(Example 10)
The same operation as in Example 9 was carried out except that the glass fiber was changed to mica (manufactured by Beijing Wenshin Trading Co., Ltd., product name: BHT Mica 200-D). As a result, the pressure at the die part and the temperature of the resin composition were good, the amount of oxidized deterioration and the amount of scum were small, and the strand stability was also good.

(Example 11)
The supply amount of PPE1 was changed to 40 parts by mass, the supply amount of glass fiber from the third supply port was changed to 15 parts by mass, and 15 parts by mass of mica (similar to Example 10) was further supplied from the third supply port. Except for this, the same procedure as in Example 9 was performed. As a result, the pressure at the die part and the temperature of the resin composition were good, the amount of oxidized deterioration and the amount of scum were small, and the strand stability was also good.

(Example 12)
A first kneading zone is installed in the barrels 3 and 4, a vacuum vent is installed in the barrel 5, a second supply port (weight feeder C) is installed in the barrel 6, a second kneading zone is installed in the barrel 7, The same extruder as in Example 3 was used except that the third kneading zone was installed in the barrel 9.
30 parts by mass of PPE 1 was charged into the weight feeder A of the extruder and supplied to the first supply port of the barrel 1. Further, 10 parts by mass of a hydrogenated styrene / ethylene block copolymer (SEBS) (manufactured by Kraton Polymers (USA), product name: G1651) as a thermoplastic resin (A), and 0.5 parts by mass of anhydrous maleic acid. A blend of an acid and 0.6 parts by mass of a stabilizer (Irganox 1010 / Adeka Stub = 1: 2) was charged into the weight feeder B and supplied to the first supply port of the barrel 1. Furthermore, 60 parts by mass of polyamide resin (66 nylon) (product name: 1300S, manufactured by Asahi Kasei Co., Ltd.) as the thermoplastic resin (A) is put into the weight type feeder C, and is supplied to the second supply port of the barrel 6. Supplied.
In the product tank, in order to prevent moisture absorption of the polyamide-based resin, a dry air generator was used to supply dry air having a dew point of −40 ° C. and an absolute humidity of 0.119 g / m ³ .
And after having mixed the raw material supplied from the 1st supply port lightly in the 1st kneading zone provided in the barrels 3 and 4 as operating conditions similar to Example 3 except having changed the screw rotation speed to 500 rpm. The raw material supplied from the second supply port of the barrel 6 was supplied and completely melted in the second kneading zone provided in the barrel 7 and the third kneading zone provided in the barrel 9 to obtain a thermoplastic resin composition. Next, in the same manner as in Example 3, the thermoplastic resin composition pellets were subjected to processes such as forming a molten thermoplastic resin composition into a strand with a die plate provided at the tip of the extruder and cutting with a pelletizer. Manufactured. As a result, as in Example 3, the pressure at the die part and the temperature of the resin composition were good, the amount of oxidation degradation products and scum generation were small, and the strand stability was also good.

(Comparative Example 6)
The same operation as in Example 12 was performed except that PPE1 was changed to PPE3. As a result, compared with Example 12, the number of oxidation degradation products increased, and the pressure in the die portion increased accordingly.

(Example 13)
Maleic anhydride was not added, and the same procedure as in Example 12 was performed except that the polyamide resin was changed to the same amount of polypropylene (Novatech PP EA9FT manufactured by Nippon Polypro Co., Ltd.). As a result, the pressure at the die part and the temperature of the resin composition were good, the amount of oxidized deterioration and the amount of scum were small, and the strand stability was also good.

(Comparative Example 7)
The same operation as in Example 13 was performed except that PPE1 was changed to PPE3. As a result, compared with Example 13, the number of oxidation degradation products increased, and the pressure in the die part increased accordingly.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing an oxidation degradation thing, generation | occurrence | production of the scum at the opening part of an orifice can be suppressed, and a good quality thermoplastic resin composition pellet can be manufactured.

DESCRIPTION OF SYMBOLS 1 Extruder 2 Die part 21 Die connection part 22 Screen changer part 23 Manifold part 24 Die plate part 24o Orifice 3 Cooling device 3a Strand cooling tank 4 Pelletizer 5 Pellet cooler 6 Pellet sorter 7 External lubricant addition device 8 Pellet conveyance device 9 Metal sorter 10 Foreign matter sorter 11 Chip separator 12 Intermediate tank (not shown)
13 Product Tank 14 Metal Detector 15 Dry Air Generator D Orifice Inner Diameter Do Orifice Inner Diameter Dc Orifice Inner Diameter L Orifice Length Lo Orifice Length Lc Orifice Length θ1 Angle L1 From Orifice Opening to Cooling Device Distance of

Claims (7)

Compression pulverizing polyphenylene ether resin to obtain compression pulverized polyphenylene ether resin;
Melt-kneading the compression-pulverized polyphenylene ether resin and the thermoplastic resin (A) to obtain a thermoplastic resin composition;
Using an extruder equipped with a die plate having a plurality of orifices having an inner diameter D of 3 to 8 mm and a length L of 0.3 to 2.0 times the inner diameter D, the orifice of the thermoplastic resin composition The average residence time T at 1 to 20 milliseconds, and obtaining a thermoplastic resin composition strand;
Pelletizing the thermoplastic resin composition strands to obtain thermoplastic resin composition pellets;
The manufacturing method of the thermoplastic resin composition pellet characterized by having.   2. The method for producing a thermoplastic resin composition pellet according to claim 1, wherein the compressed pulverized polyphenylene ether has an average particle diameter of 1000 to 3000 μm and a ratio of the particle diameter of 106 μm or less is 20% by mass or less.   The thermoplastic resin composition pellet according to claim 1 or 2, wherein the thermoplastic resin (A) is at least one selected from the group consisting of a polystyrene resin, a polyamide resin, a polyolefin resin, and polyphenylene sulfide. Manufacturing method.   The length Lo of the orifice located at the outermost end in the width direction of the die plate among the plurality of orifices is located closest to the center in the width direction of the die plate among the plurality of orifices. The manufacturing method of the thermoplastic resin composition pellet in any one of Claims 1-3 which is 0.5 to 0.8 times the length Lc of an orifice.   Of the plurality of orifices, the inner diameter Do of the orifice positioned at the outermost end in the width direction of the die plate is positioned closest to the center of the plurality of orifices in the width direction of the die plate. The manufacturing method of the thermoplastic resin composition pellet in any one of Claims 1-4 which is 1.05-1.3 times the internal diameter Dc of this.   The method for producing a thermoplastic resin composition pellet according to any one of claims 1 to 5, wherein a surface hardness of at least a part of a surface of the die plate where the orifice opens and an inner surface of the orifice is 800 to 5000.   On the downstream side of the extruder, a cooling device, a pelletizer, a dehydrating device, a pellet cooling device, a pellet sorting device, an external lubricant addition device, a pellet conveying device, a metal sorting device, a foreign material sorting device, a chip separator, an intermediate tank, The method for producing a thermoplastic resin composition pellet according to any one of claims 1 to 6, wherein at least one selected from the group consisting of a product tank, a metal detector, a dry air generator, and a dehydrator is further used.

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