JP2000263547A - Preparation of reinforced thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain pellets with small fluctuation of filler content in preparing a reinforced thermoplastic resin compsn. contg. a fibrous or needle-like filler with a low bulk density and as the result, to obtain a molded article with small fluctuation of dimensional accuracy, etc., even in a case where an especially micro-part is prepd. SOLUTION: In a method wherein a thermoplastic resin (an ingredient A) and a fibrous or a needle-like filler (an ingredient B) with a bulk density of 200-450 g/l are respectively individually fed into an extruder from a feeder and are melted and kneaded to prepare pellets of a thermoplastic resin compsn., the feeder for feeding the ingredient B has a metering hopper 7 with a hopper angle 10 of 85-95 degree.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a reinforced thermoplastic resin composition. More specifically, the present invention relates to a method for producing a reinforced thermoplastic resin composition capable of producing uniform pellets with little variation even in a filler having low bulk density and poor supply stability.

[0002]

2. Description of the Related Art Thermoplastic resins have good moldability, light weight,
Because of its good electrical insulation, water resistance, heat insulation, corrosion resistance, etc., it can be used as an alternative material for metals, glass, ceramics, wood, etc., as electrical and electronic parts, mechanical parts, OA parts, medical parts,
Used in all fields such as automotive parts. In recent years, particularly in electric and electronic parts, OA parts, and the like, there are cases where extremely small parts are required as the parts become thinner, smaller, and lighter. These parts are usually produced by molding resin pellets using an injection molding machine or the like, and there are many parts as small or light as the resin pellets.

[0003] On the other hand, these minute components are compounded with a fibrous or needle-like filler such as glass fiber, carbon fiber, aramid fiber or various whiskers, rock wool and wollastonite in order to secure rigidity and dimensional stability. Often do. Particularly in recent years, the use of carbon fibers has been increasing in order to secure sufficient rigidity.

As a method of blending the above-mentioned various fibrous or needle-like fillers with a thermoplastic resin, for example, a method of using an extruder to coat and cut the thermoplastic resin around the fiber roving bundle (see, for example). Method 1), a method in which a mixture of a thermoplastic resin and an inorganic filler in advance is melt-kneaded in an extruder and cut (referred to as Method 2). Further, the thermoplastic resin and the filler are separately provided with a measuring device. There is a method in which a desired composition is metered and supplied to an extruder using a feeder, melt-kneaded in the extruder, and cut (method 3).

[0005] In the above method 1, it is difficult to disperse the filler in the molded product, and large variations occur in rigidity and dimensional accuracy of the molded component. In method 2, although the inorganic filler is once mixed with the thermoplastic resin uniformly, especially in the case of the filler having a low bulk density and a fibrous or needle-like filler, a separation phenomenon between raw materials generally called classification is caused. It tends to occur, and the content of the filler in the pellets varies. As a result, particularly when minute components are formed, the rigidity and the dimensional accuracy also tend to vary. Further, since the kneading is performed simultaneously from the solid phase, the fibrous or needle-like filler is broken, and the desired rigidity and dimensional accuracy cannot be obtained in this regard.

On the other hand, the above method 3 is a method which does not have the drawbacks of these methods 1 and 2, since the filler is dispersed in the resin and can be supplied in a molten state having a low resin viscosity. It is widely used as a method for producing a thermoplastic resin containing a filler.

However, in the method 3,
When using a fibrous or needle-like filler with a low bulk density, the flow in the weighing hopper and other parts of the feeder that supplies the filler tends to be unstable, so the content of the filler between pellets There has been a problem that variations occur, and as a result, variations in dimensional accuracy and rigidity occur particularly when manufacturing minute components.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reinforced thermoplastic resin composition containing a fibrous or needle-like filler having a low bulk density, by using pellets having a small filler content variation. It is an object of the present invention to provide a manufacturing method which can obtain a molded product which can be obtained with a small variation in dimensional accuracy and the like even when a minute component is manufactured.

The inventor of the present invention has conducted intensive studies in order to achieve this object, and as a result, the desired composition has been added to the extruder by using a metering feeder separately for the thermoplastic resin and the filler having a low bulk density. In the method of metering, melt-kneading and cutting in an extruder, by supplying such a filler by a feeder having a specific hopper angle, stable supply is possible even when the bulk density is low, and pellets The present inventors have found that the dispersion of the content of the filler between the layers can be reduced, and arrived at the present invention.

[0010]

That is, according to the present invention, a thermoplastic resin (A component) and a bulk density of 200 to 450 g /
l in a method of producing thermoplastic resin composition pellets by independently supplying a fibrous or needle-like filler (component B) to an extruder from a feeder and melt-kneading the same. A method for producing a reinforced thermoplastic resin composition, wherein the feeder has a weighing hopper having a hopper angle of 85 to 95 degrees. Is provided.

The thermoplastic resin used as the component A in the present invention includes aromatic polycarbonate resins, styrene resins, aromatic polyester resins, polyolefin resins,
Polyarylate resin, polyamide resin, polyphenylene ether resin, polysulfone resin, polyphenylene sulfide resin, polyalkyl methacrylate resin, thermoplastic polyurethane elastomer, thermoplastic polyester elastomer, polyether sulfone resin, phenoxy resin, polyether ether ketone resin, polyvinyl chloride Resins, polyacetal resins, polyimide resins, and the like can be given, and among them, aromatic polycarbonate resins are preferred. It is also possible to use a combination of two or more of these thermoplastic resins.

The styrenic resin referred to in the present invention includes homopolymers or copolymers of styrene derivatives such as styrene, α-methylstyrene and p-methylstyrene, and these monomers and acrylonitrile and methyl methacrylate. Copolymers with vinyl monomers are mentioned. Further, a composite having a structure in which a diene rubber such as polybutadiene, an ethylene / propylene rubber, an acrylic rubber, and a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate rubber component are intertwined so that they cannot be separated. Rubber (hereinafter referred to as IPN type rubber) or the like may be obtained by graft-polymerizing styrene and / or a styrene derivative, or styrene and / or a styrene derivative and another vinyl monomer.

Examples of the styrene resin include polystyrene, styrene / butadiene / styrene copolymer (SBS), hydrogenated styrene / butadiene / styrene copolymer (hydrogenated SBS), and hydrogenated styrene / isoprene / styrene copolymer. Coalescence (SEPS), impact polystyrene (HI)
PS), acrylonitrile / styrene copolymer (AS resin), acrylonitrile / butadiene / styrene copolymer (ABS resin), methyl methacrylate / butadiene / styrene copolymer (MBS resin), methyl methacrylate / acrylonitrile / butadiene / styrene copolymer Polymer (MABS resin), Acrylonitrile / Acrylic rubber / Styrene copolymer (AAS resin), Acrylonitrile / Ethylene propylene rubber / Styrene copolymer (AE
S resin) and a resin such as a styrene / IPN type rubber copolymer, or a mixture thereof.

The styrene-based thermoplastic resin may be one having a high stereoregularity such as syndiotactic polystyrene by using a catalyst such as a metallocene catalyst at the time of its production. Further, in some cases, a polymer and a copolymer having a narrow molecular weight distribution obtained by a method such as anionic living polymerization or radical living polymerization, a block copolymer, and a highly stereoregular polymer or copolymer are used. It is also possible. A compound having a functional group such as maleic anhydride or N-substituted maleimide can be copolymerized with the styrene resin.

The polyolefin resin used in the present invention includes high-density polyethylene resin, low-density polyethylene resin, linear low-density polyethylene resin, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-acrylic acid. Examples thereof include an ester copolymer, an ethylene-glycidyl (meth) acrylate copolymer, polypropylene, a propylene-vinyl acetate copolymer, and polymethylpentene.

The thermoplastic resin as the component A of the present invention includes:
Further, if desired, a flame retardant, an anti-drip agent, a flame retardant aid, a heat stabilizer, a light stabilizer, an antistatic agent, a sliding agent, a release agent, a colorant, an impact modifier, and the component B other than the present invention May be mixed. Further, the thermoplastic resin as the component A is usually supplied to the extruder in a solid state such as powder, particles, and pellets, but may be in a liquid state such as an emulsion. .

The bulk density used as the component B in the present invention is 2
In the fibrous or needle-like filler of 00 to 450 g / l, as the fibrous or needle-like filler, glass fiber chopped strand, carbon fiber chopped strand, potassium titanate whisker, aluminum borate whisker, titanium oxide whisker, Various synthetic whiskers such as zinc oxide whiskers, calcium carbonate whiskers and basic magnesium sulfate whiskers, and inorganic fillers obtained from natural inorganic minerals such as wollastonite, sepiolite, zonotolite, dawsonite, franklin fiber, and rock wool, and aramid Heat-resistant organic fibers such as fibers and polyarylate fibers can be used.

[0018] Among these, glass fiber chopped strands, carbon fiber chopped strands, aramid fibers, and polyarylate fibers obtained by cutting rovings are usually epoxy resins, urethane resins or acrylic resins, or mixtures thereof. And a sufficiently high bulk density, so that there is no particular problem in transportation and supply to the extruder.
However, particularly in the case of carbon fiber, the affinity of the surface of the carbon fiber itself is poor, and the convergence treatment is often insufficient. Even if the product is once bundled, such a bundle may be produced during transportation of the carbon fiber product, during transportation from the storage tank to the extruder measuring device, or due to agitation such as stirring blades or vibration in the feeder. The phenomenon that the bundle of carbon fibers is easily cleaved and the bulk density becomes high when actually supplied from the supply machine to the extruder is likely to occur. On the other hand, if the amount of the sizing agent is increased for the purpose of improving the sizing property, there is a case where such a measure is not preferable because the sizing agent adversely affects desired performance such as strength and flame retardancy.

Among such fibrous or acicular inorganic fillers, carbon fibers can be preferably used in terms of high rigidity, light weight, strength and the like. On the other hand, such a variation in the content of the carbon fiber due to the strength of the reinforcing effect has a great effect on dimensional stability such as rigidity and molding shrinkage, and the effect of the present invention is further exhibited. The present invention is a method capable of producing pellets having a small content variation even in a carbon fiber chopped strand in which sufficient bunching property is not obtained and bulk density becomes high.

On the other hand, wollastonite is also difficult to converge because such a filler is obtained by pulverization of minerals, so that problems are likely to occur in transportation and supply, and the effect of the present invention is more exhibited. It can be mentioned as a preferable inorganic filler.

The chopped carbon fiber strand used in the present invention is generally produced by firing from cellulose fiber, acrylonitrile fiber, rayon fiber, vinylon fiber, lignin, petroleum or coal-based special pitch, and is fire-resistant. Various types such as carbonaceous, carbonaceous or graphitic can be used. Further, the obtained carbon fiber has a volume resistivity value of 10 ^-1 to 10 ^-4 Ωcm and a good conductivity, and 10 ^-1 to 10 ³ Ωcm.
Any of the low conductivity types can be used.

The length of the chopped carbon fiber strand is usually in the range of 0.2 to 20 mm, and the fiber diameter of the carbon fiber is in the range of 3 to 15 μm. The surface of these carbon fibers is preferably surface-treated with a conventionally known silane coupling agent, titanate coupling agent, aluminate coupling agent, or the like, and is preferably an olefin resin, a styrene resin, a polyester resin, or an epoxy resin. It is preferable to use a resin or a urethane-based resin that has been subjected to a convergence treatment. The amount of the sizing agent is 1 to 10 when the entirety of the carbon fiber chopped strand after the sizing treatment is 100% by weight.
%, Preferably 1.5 to 6% by weight. Within such a range, the sizing property is inferior, so that the bulk density when actually supplied from the feeder to the extruder is easily maintained at 200 g / l or more. Good characteristics can be maintained without adversely affecting the characteristics of the resin composition.

Further, the carbon fiber can be oxidized by a usual method such as ozone, plasma, nitric acid, electrolysis or the like before the bunching treatment, and the treated fiber can be preferably used.

In the present invention, the B component has a bulk density of 200
~ 450 g / l of fibrous or needle-like inorganic filler is fed to the extruder.

In the present invention, the B component having the above-mentioned specific bulk density is supplied by a feeder in which the hopper angle of the measuring hopper of the feeder is 85 degrees or more and 95 degrees or less. Things. When the hopper angle is smaller than 85 degrees, the resistance when the filler falls through the weighing hopper due to friction with the inner wall surface increases while the inorganic filler of the component B stays in the weighing hopper. If the stable supply is insufficient and the hopper angle is greater than 95 degrees, the dimension of the upper part of the hopper becomes too small compared to the dimension of the inlet from the weighing hopper to the feeder, and the function as the hopper is sufficiently satisfied. Not preferred.

The hopper angle defined in the present invention is the inclination angle of the hopper inner wall surface. Therefore, for example, those having a rectangular shape, a hexagonal prism, a cylinder, a truncated cylinder, a truncated pyramid, a truncated cone, and the like can be given. However, it is sufficient that not only these general shapes but also each inner wall surface of the hopper substantially satisfies the range specified in the present invention. Therefore, a combination of a cylindrical shape and a truncated cone,
One having an elliptical cross section can also be mentioned. Further, the hopper angle defined by the present invention is the angle of the inner wall surface substantially possessed by the hopper to be used, and by providing minute unevenness or the like on the hopper inner wall surface, a portion outside the range of the hopper angle defined by the present invention. May be included.

The weighing hopper in the present invention refers to a portion for accumulating the raw materials attached to the feeder, and more specifically, a portion of the feeder which receives an external force for actual feeding by vibration, a screw, a stirring blade or the like. The part that stores some raw material in the foreground. Generally, it is independent as a weighing hopper portion for the purpose of facilitating washing in the feeder, and is usually fixed to the feeder. The portion (hereinafter, referred to as a supply hopper portion) from the measuring hopper portion until the filler actually receives an external force for supply is not an object of the measuring hopper of the present invention. For example, a vibration feeder (vibration type feeder) usually has a fixed weighing hopper and a feed hopper portion such as a truncated pyramid or a truncated cone that is fixed with an elastic body interposed therebetween so as to be movable. However, such a portion is not an object of the hopper according to the present invention.

If the supply port portion of the supply hopper portion is inappropriate, the effect of the present invention cannot be sufficiently exerted. Therefore, the supply hopper portion should be as low as possible, and the inclination angle should be small. It is better to be as close as possible to 90 degrees.

The weighing hopper of the present invention includes a mechanism (knocker or the like) for adjusting the flow of the filler in the hopper by applying an external impact or vibration to the hopper, and a stirring blade for stirring the entire inside of the hopper. It is also possible to install. However, the focused filler only promotes cleavage of the bundle and causes the formation of entangled masses of the filler in the weighing hopper, so that these stimuli are provided only to the extent that the object of the present invention is not impaired. Should be
In particular, a weighing hopper which does not cause irritation by such a knocker or a stirring blade is preferable in the present invention.

Further, the material of the measuring hopper used in the present invention is not particularly limited, and it is possible to use materials such as glass, wood, resin and the like in addition to ordinary metals such as stainless alloys and aluminum alloys. It is. The inner surface is preferably smooth. Further, such a hopper may be one in which only the inner wall surface is coated with a fluorine resin, a silicone resin, or the like.

When a resinous material is used, A
If a thermoplastic resin similar to the main component of the thermoplastic resin is used, it is possible to suppress the adverse effect of a slight wear component caused by wear of the inner wall surface by the filler. Further, if a transparent resin such as a polycarbonate resin is used, there is an advantage that the situation inside the hopper can be easily grasped.

Examples of the feeder used in the present invention include a vibration feeder, a screw feeder, a table feeder, a shaking feeder, a plunger feeder, a reciprocating feeder, a rotary feeder and the like.

In the present invention, a plurality of feeders for supplying the component A or the component B may be provided. In addition to the component A and the component B, a flame retardant, an anti-drip agent, a flame retardant auxiliary, a heat stabilizer,
Even those which supply a light stabilizer, an antistatic agent, a sliding agent, a release agent, a colorant, an impact modifier, a filler other than the component B of the present invention, or a thermoplastic resin other than the component A Good. That is, the reinforced resin composition obtained in the present invention may contain the various fillers listed above in addition to the thermoplastic resin of the component A and the filler of the component B.

Further, the extruder used in the present invention may have one or more supply ports, and particularly preferably has two or more supply ports. The method of supplying the raw materials to the extruder is a method of supplying each raw material from one supply port, or a method of supplying each raw material from different supply ports in an extruder having two or more supply ports. Is also good. The component A is supplied in a solid state such as powder, granules, and pellets, and the component A capable of being melt-polymerized, such as an aromatic polycarbonate resin, is kept in the molten state according to the method of the present invention. To supply the B component. Regarding a resin such as an ABS resin which directly supplies a dispersion or the like to an extruder, the component B can be charged in the middle of the extruder by the method of the present invention.

The type of the extruder is not particularly limited as long as it is an extruder such as a single-screw extruder or a twin-screw extruder, but a twin-screw extruder is more preferable in terms of uniformity of dispersion. Further, the screw can be arbitrarily selected according to the thermoplastic resin and the filler to be extruded, and the purpose thereof.

[0036]

The present invention will be further described below with reference to examples, but the present invention is not limited thereto. The following items were evaluated.

(1) Filler Content in Pellet When the reinforced thermoplastic resin composition was produced by the production method described in each of the examples below, the pellet was added every 10 minutes to 500.
Sampling was performed six times for each g, and the amount of the filler contained in the pellet was measured. The filler content was determined by taking 3 g of pellets, placing them in an Erlenmeyer flask, adding 100 ml of methylene chloride therein, dissolving them for 3 hours by allowing them to stand naturally, and then dissolving the paper (manufactured by Toyo Roshi Kaisha, Ltd., product name NO.
8012 type equivalent)) and filtered with a box drier
After drying at 30 ° C. for 30 minutes, the residue was calculated as the filler content.

(2) Measurement of Run-out of Rotational Molded Product The sampling pellets obtained at the respective times obtained above were uniformly mixed, dried at 120 ° C. for 5 hours, and then turned into a mini disk turntable shown in FIGS. 1 and 2. Was formed. Molding is carried out by injection molding with an injection molding machine (clamping pressure 40 TON) under the conditions of a cylinder temperature of 310 ° C., a mold temperature of 120 ° C., and other conditions. The first 20 pieces are discarded, and thereafter. 100 molded articles were formed at random, and 10 were randomly taken out of the molded articles.
It was left for 24 hours in a 50 ° C., 50% RH atmosphere. Then, a jig for measurement is attached to the shaft insertion hole of the turntable molded product, and the test indicator (manufactured by Mitutoyo Corporation) is used to measure the amount of runout [μ] of the turntable molded product disk mounting surface.
m] was measured. According to this evaluation method, the smaller the surface runout amount is, the better the surface runout is.

[Example 1] Panlite L-1225WP manufactured by Teijin Chemicals Ltd. was used as a polycarbonate resin, and CFC-ET manufactured by Lignite Co., Ltd. (fiber length: 6 mm, bulk density: 300) was used as a carbon fiber chopped strand.
g / l, moisture 0.2% by weight, adhesion amount of mixed sizing agent of epoxy and urethane 6% by weight). This polycarbonate resin is supplied to a screw-type feeder (Kubota Co., Ltd., twin-screw cassette weighing feeder NT-
30 kg is put into CWF (model: CE-T-II, agitator: vertical standard) and the lower limit of the hopper capacity is 5 kg.
Was set so that the hopper content was reduced to 30 kg. With this screw type feeder, a twin screw extruder TEX44HCT-3 manufactured by Nippon Steel Works, Ltd.
It was supplied at a rate of 80 kg / hour to the first supply port (supply port at the end of the screw) of 1.5 AW-2V. On the other hand, this carbon fiber chopped strand was fed to the second feed port of the extruder at 20
In feeding at a rate of kg / hour by the side feeder, the shape of the weighing hopper of the feeder is a cylindrical shape shown in FIG. 3, and a screw-type feeder feeder equipped with a weighing hopper having a hopper angle of 90 degrees ( (stock)
10 to Kubota twin-screw cassette weighing feeder wide range CWF (model: CE-WI)
kg, and when the lower limit of the hopper content became 3 kg, the hopper content was set so that the hopper content became 10 kg. This screw feeder fed into the extruder cylinder via a side feeder. Extrusion was performed under the conditions of a cylinder temperature of 300 ° C., a screw rotation speed of 160 rpm, a vent suction, and a discharge rate of 100 kg / hour.
A pellet was obtained by a pelletizer.

[Example 2] The supply amount of the polycarbonate resin was 120 kg / h, and the supply amount of the carbon fiber chopped strand (CFC-ET manufactured by Lignite Co., Ltd.) was 30 k.
g / h, and the extrusion conditions were a cylinder temperature of 300 ° C,
Extrusion was performed in the same manner as in Example 1 except that extrusion was performed under the conditions of a screw rotation speed of 200 rpm, vent suction, and a discharge rate of 150 kg / hour, to obtain pellets.

Example 3 As a feeder for carbon fiber chopped strands (CFC-ET manufactured by Lignite Co., Ltd.), a hopper having a square tubular shape shown in FIG. 4 and a hopper angle of 90 degrees was attached. 10 kg into a vibrator-type feeder (vibration-type cassette weighing feeder CWF (model: CE-FI) manufactured by Kubota Co., Ltd.).
It was set so that it would be charged until it reached 0 kg. At this time, the height of the layer thickness adjustment gate from the feeder trough is set at 30.
mm. Pellets were obtained in the same manner as in Example 1 except that this vibrator-type feeder was used.

Example 4 As a feeder for carbon fiber chopped strands (CFC-ET manufactured by Lignite Co., Ltd.), a disk-type feeder (Yamato) with a cylindrical shape and a hopper with a hopper angle of 90 degrees was installed. Disc type feeder manufactured by Seikyo Co., Ltd., Model: LDF-60
B) was used, and 10 kg was charged. When the lower limit reached 3 kg, the hopper was set so that the internal capacity became 10 kg. Others were carried out similarly to Example 1, and obtained the pellet.

[Example 5] As a feeder for carbon fiber chopped strands (CFC-ET manufactured by Lignite Co., Ltd.), the hopper angles of the A and C planes in the hopper shown in FIG. Surface hopper angle is 9
A pellet was obtained in the same manner as in Example 3 except that a hopper at 0 ° was attached.

Example 6 A thermoplastic resin obtained by adding 0.2% of an acid-modified polyolefin wax (Diacarna 30 manufactured by Mitsubishi Chemical Corporation) to a polycarbonate resin L-1225WP and mixing uniformly was used. And pellets were obtained in the same manner as in Example 4 except that wollastonite (Psychatec NN-4 manufactured by Tomoe Kogyo Co., Ltd., bulk density: 390 g / l, fiber length: 45 μm, no sizing agent) was used as a filler. .

Example 7 As carbon fiber chopped strand, Vesfight HTA- manufactured by Toho Rayon Co., Ltd.
A pellet was obtained in the same manner as in Example 3, except that C6-U (bulk density: 325 g / l, adhesion amount of epoxy and urethane mixed sizing agent: about 2.5%, fiber length: 6 mm) was used.

[Comparative Example 1] As a feeder of carbon fiber chopped strand (CFC-ET manufactured by Lignite Co., Ltd.), it has a frusto-conical shape as shown in FIG. 6 and the hopper angle on the inner wall surface of the hopper is 70 degrees. A pellet was obtained in the same manner as in Example 1 except that a screw feeder to which a certain hopper was attached was used.

[Comparative Example 2] As a feeder of carbon fiber chopped strand (CFC-ET manufactured by Lignite Co., Ltd.), it has a truncated cone shape as shown in FIG. 6, and the hopper angle on the inner wall surface of the hopper is 70 degrees. A pellet was obtained in the same manner as in Example 2 except that a screw feeder to which a certain hopper was attached was used.

[Comparative Example 3] As a feeder of carbon fiber chopped strands (CFC-ET manufactured by Lignite Co., Ltd.), the hopper angles of the A and C planes in the hopper shown in FIG. Surface hopper angle is 9
A pellet was obtained in the same manner as in Example 3 except that a hopper at 0 ° was attached.

[Comparative Example 4] As a feeder for carbon fiber chopped strand (CFC-ET manufactured by Lignite Co., Ltd.), it has a truncated conical shape as shown in FIG. 6, and the hopper angle on the inner wall surface of the hopper is 70 degrees. Example 1 except that a disk feeder (a disk type feeder manufactured by Daiwa Seisaku Co., Ltd., model LDF-60B) equipped with a certain hopper was used.
And pellets were obtained.

Comparative Example 5 As a wollastonite feeder, a disk feeder (manufactured by Daiwa Seiki Co., Ltd.) equipped with a hopper having a frusto-conical shape shown in FIG. Disc type feeder, model LD
F-60B), except that F-60B) was used.
A pellet was obtained.

[Comparative Example 6] As carbon fiber chopped strand, Vesfight HTA- manufactured by Toho Rayon Co., Ltd.
Pellets were obtained in the same manner as in Comparative Example 3 except that C6-U (bulk density: 325 g / l, adhesion amount of epoxy and urethane mixed sizing agent: about 2.5%, fiber length: 6 mm) was used.

[0052]

[Table 1]

[0053]

[Table 2]

The following is clear from this table. From the comparison between Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2, the pellets produced by the method of the present invention have a small filler content variation regardless of the type of feeder. As a result, it can be seen that stable dimensional accuracy of the molded article was obtained.

[0055]

As is clear from the above, the method for producing a reinforced thermoplastic resin composition of the present invention uses a filler having a low bulk density and an unstable flow when supplied to an extruder. Even in this case, there is little variation in the filler content between the pellets, and as a result, a molded product having stable dimensions and the like can be obtained. Especially mini-disc turntables,
It is useful for minute parts and the like that require high dimensional accuracy, such as gears of precision machines, and the industrial effects achieved are extremely large.

[Brief description of the drawings]

FIG. 1 is a front schematic view of a simulation molded product of a mini disk turntable as an evaluation sample.

FIG. 2 is a schematic rear view of a simulated molded product of a minidisk turntable which is an evaluation sample (corresponding to a diagram in which the broken line portion in FIG. 1 is inverted).

FIG. 3 is a diagram schematically illustrating an outline of a screw-type feeder having a cylindrical hopper.

FIG. 4 is a diagram schematically illustrating an outline of a vibration type feeder having a rectangular cylindrical hopper.

FIG. 5 is a diagram schematically illustrating a hopper having a truncated quadrangular pyramid shape.

FIG. 6 is a view schematically showing a frusto-conical hopper.

[Explanation of symbols]

1 Minidisc turntable body (outside diameter 16 mm) as an evaluation sample 2 Surface for measuring runout value on turntable 3 Guide for mounting disc (outside diameter: 10.
5 Hole for inserting a shaft 5 Dashed line for representing the relationship between FIGS. 1 and 6 6 Gate (three identical parts) 7 Weighing hopper 8 Weighing hopper diameter (250 mm) 9 Weighing hopper height (750 mm) 10 weighing hopper angle 11 agitator 12 supply hopper 13 supply twin screw 14 casing 15 weighing hopper 16 weighing hopper length (250 mm) 17 weighing hopper width (250 mm) 18 weighing hopper height (750 mm) 19 weighing hopper angle (90) Degree) 20 supply hopper 21 feeder trough 22 feeder trough width (120 mm) 23 feeder trough height (60 mm) 24 supply hopper width (100 mm) 25 supply hopper length (210 mm) 26 feeder trough length (550 mm) 27 layers Control gate 28 weighing hopper A surface 29 weighing hopper B surface 30. Weighing hopper C plane 31 weighing hoppers D surface 32 weighing hopper angle 33 frusto conical metering hopper 34 Weighing hopper angle

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 3/20 CEQ C08J 3/20 CEQB CER CERB CEZ CEZB C08K 7/02 C08K 7/02 7/06 7 / 06 7/10 7/10 C08L 101/16 C08L 101/00 // B29K 105: 12 105: 16 507: 04 509: 00 F term (reference) 4F070 AA06 AA12 AA13 AA15 AA16 AA18 AA22 AA28 AA32 AA33 AA42 AA47 AA50 AA52 AA53 AA54 AA55 AA58 AA59 AB08 AC11 AC14 AC16 AC18 AC20 AC22 AC28 AC88 AC90 AD02 AE01 DA04 DA05 FA01 FA03 FC05 FC08 FC09 4F072 AA02 AA03 AA08 AB05 AB06 AB08 AB09 AB10 AB21 AC04 AC05 AC06 AD04 AD05 AD43 AD43 AD11 AD43 AD43 AD46 AD09 AD52 AD53 AG05 AH04 AH13 AH34 AJ33 AJ35 AJ40 AK04 AL11 AL16 4F201 AB11 AB16 AB18 AC01 AD16 AL15 AL16 AR15 BA02 BC01 BC12 BC17 BC19 BC37 BD05 BL08 BL2 8 BQ02 BQ08 BQ48 4J002 BB031 BB061 BB071 BB121 BB141 BB151 BB171 BC031 BC061 BD041 BG051 BN061 BN121 BN141 BN151 BN161 BP011 CB001 CF006 DJ041 CF101 CF161 CF162 CF171 CG001 CH011 C031 FA066 FD012 FD016 FD040 FD060 FD090 FD100 FD130 FD160

Claims (3)

[Claims] 1. A thermoplastic resin (component (A)) having a bulk density of 2
In a method for producing a thermoplastic resin composition pellet, a fibrous or needle-like filler (component B) of 00 to 450 g / l is independently supplied to an extruder from a feeder and melt-kneaded. The feeder that supplies the components has a hopper angle of 8
A method for producing a reinforced thermoplastic resin composition, comprising a weighing hopper of 5 degrees or more and 95 degrees or less. 2. The method for producing a reinforced thermoplastic resin composition according to claim 1, wherein the component B is a chopped carbon fiber strand. 3. The B component is wollastonite.
The method for producing a reinforced thermoplastic resin composition according to the above.