JP2003103517A - Method for manufacturing thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for obtaining a thermoplastic resin composition which can stably manufacture the composition obtained by blending raw materials each having a low bulk density and which has the small variation of the contents of the raw material components. SOLUTION: The method for manufacturing the thermoplastic resin composition comprises a step of melt kneading a high bulk raw material and a thermoplastic resin by using an extruder. The extruder has two or more supply ports. The method further comprises the steps of supplying the raw material (stock A) containing the thermoplastic resin to a first supply port of the upstream side to melt the material, simultaneously supplying a specific high bulk raw material (stock B) and other raw material (stock C) having a relationship between the specific bulk density and a true density to the supply port of the lower stream side than the first supply port, and melt-kneading the melted raw material A.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a thermoplastic resin composition prepared by blending raw materials having a high dryness (low dry density). More specifically, the present invention relates to a manufacturing method in which an extruder having two or more supply ports is used to supply a raw material having a low bulk density by a specific supply method, and a thermoplastic resin composition having a small variation in filling amount can be manufactured. .

[0002]

2. Description of the Related Art Thermoplastic resins are used for molding processability, light weight,
Since it has good electrical insulation, water resistance, heat insulation, corrosion resistance, etc., it can be used as a substitute material for metals, glass, ceramics, wood, etc., as electrical and electronic parts, machine parts, OA parts, automobile parts, medical parts, etc. It is used in all fields.

Further, various reinforcing materials are often mixed with the thermoplastic resin. There are many extremely bulky raw materials for these reinforcing materials. Although resin compositions comprising a thermoplastic resin and a reinforcing material are generally manufactured today by using an extruder, such a bulky raw material has a drawback that the supply to the extruder tends to be unstable.

The applicant of the present invention has already disclosed in Japanese Patent Laid-Open No. 2000-26354.
In the method of producing pellets of the composition by supplying a composition comprising a bulky raw material typified by wollastonite and carbon fiber and a thermoplastic resin to a pellet of the composition, the raw material is fed to the extruder. It is proposed that by using a metering hopper having a hopper angle close to 90 ° as a supply hopper, stable supply becomes possible and good pellets can be obtained.

However, there are still cases where problems may occur. For example, when the raw material fed from the weighing machine to the extruder accumulates little by little in the hopper mounted on the side feeder, which impairs the stability of feeding, or the biting into the side feeder is not good enough. There are cases. Further, as a result, there are cases where the resin composition has insufficient thermal stability. These problems tend to occur in, for example, continuous production for a long time or production near the upper limit of the feeding capacity of the extruder. These problems cannot be sufficiently addressed by the invention described in the above publication.

[0006]

The object of the present invention is to enable stable production in the production of a thermoplastic resin composition prepared by blending raw materials having a low bulk density, and to improve the content of the raw material components. It is an object of the present invention to provide a manufacturing method capable of obtaining a thermoplastic resin composition having a small variation.

As a result of intensive studies to achieve the above object, the inventors of the present invention have used an extruder having two or more supply ports and used a raw material containing a thermoplastic resin at the most upstream first supply port. After being supplied and melted, an extruder having a high bulkiness can be obtained by simultaneously supplying the raw material having a high bulkiness and the raw material having a specific bulk density characteristic to one supply port downstream from the first supply port. It has been found that a resin composition that can be supplied to the resin composition can be supplied to the resin composition, the variation in the content of the components can be reduced, and the thermal stability can be further improved.

[0008]

That is, the present invention is a method for producing a thermoplastic resin composition by melt-kneading a bulky raw material and a thermoplastic resin using an extruder, wherein the extruder is A raw material (raw material A) containing a thermoplastic resin is supplied to the first supply port, which is the most upstream of the supply ports, and melted, and one supply is provided downstream from the first supply port. A raw material having a high bulk (raw material B) satisfying the following formula (1) and another raw material (raw material C) satisfying the following formula (2) are simultaneously supplied to the mouth to melt-knead the melted raw material A. And a method for producing a thermoplastic resin composition. 0.1 ≦ (bx / by) <0.3 (1) 0.5 ≦ (cx / cy) ≦ 1 (2) (where, bx is the bulk density (g / cm ³ ) of the raw material B, b
y is the true density of the raw material B (g / cm ³ ), cx is the bulk density of the raw material C (g / cm ³ ), and cy is the true density of the raw material C (g / c ³ ).
m ³ ))

Furthermore, the present invention preferably relates to the above-mentioned manufacturing method, wherein the feed of the raw material B and the raw material C to the extruder satisfies the following formula (3). bs / (bs + cs) ≦ 0.9 (3) (where, bs is the feed rate (kg / h) of the raw material B to the extruder feed port, and cs is the feed rate of the raw material C to the extruder feed port (kg) / H))

Furthermore, the present invention is preferably such that the thermoplastic resin composition comprises 100 to 9% by weight of the composition, the raw material A being 30 to 98.5% by weight, and the raw material B being 0.5 to 0.5% by weight. ˜50% by weight, and raw material C as its component 1
The present invention relates to the above-mentioned manufacturing method, which contains 50% by weight.

Furthermore, the present invention preferably relates to the above-mentioned manufacturing method in which the raw material B is wollastonite, and the above-mentioned manufacturing method in which the raw material C is a pellet of a thermoplastic resin, Preferably, the raw material A is mainly composed of an aromatic polycarbonate resin, and the raw material B is
Is wollastonite, and the raw material C is a pellet of an aromatic polyester resin. The details of the present invention will be described below.

The extruder having two or more supply ports used in the present invention may be of any type as long as it is an extruder capable of melting a thermoplastic resin to obtain pellets or molded articles. For example, a single-screw extruder, a twin-screw extruder, a multi-screw extruder (extruder having two or more screws), and a planetary roller extruder can be mentioned.

A typical example of the single screw type extruder is a type in which full flight is combined with dullage or torpedo. In addition, a type having two screws only in the feed portion and a special type such as a transfer mix can also be mentioned.

A typical example of the twin-screw type extruder is ZSK (Werner & Pfleiderer).
Company name, trade name). Specific examples of similar types include TEX (manufactured by Japan Steel Works, trade name), TEM (manufactured by Toshiba Machine Co., Ltd., trade name), KTX.
(Kobe Steel Co., Ltd., trade name) and the like. In addition, FCM (Farrel, product name),
Ko-Kneader (made by Buss, trade name), and DSM (made by Krauss-Maffei, trade name)
Specific examples include melt-kneaders such as.

Further, as the above-mentioned screw type extruder, a conical screw type or a type in which the plasticizing step and the metering step are independent can be mentioned. Among the above extruders, a twin-screw extruder is preferable, and further Z
The type represented by SK is more preferable.

In the twin-screw extruder, the rotation direction of the screw is not particularly limited, either the same direction rotation or different direction rotation can be used, and the same direction rotation is more preferable. In addition, the screw can be selected as appropriate, and for example, the shape can be 1, 2,
A three-thread screw can be used. Two
A thread screw can be used more preferably. Furthermore, the ratio (L / D) of the length (L) and the diameter (D) of the screw is
20-40 are preferable and 28-40 are more preferable. L
When / D is large, it is easy to increase the number of supply ports. On the other hand, when it is too large, the heat load on the resin composition, especially the raw material A becomes high, which is not preferable in some cases.

Various specifications are possible for the screw configuration of the twin-screw extruder. The fact that such specifications can be changed arbitrarily is also a great advantage of the ZSK type. The screw preferably has at least one kneading zone composed of a kneading disk segment (or a kneading segment corresponding thereto) for improving the kneading property. Further, in the present invention, since the raw material is supplied from two or more supply ports, it is more preferable to provide two or more kneading zones.

In the present invention, of the two or more extruder supply ports, the most upstream side (the side farthest from the extruder die part) is the first supply port, and the downstream side from the first supply port. They are referred to as a second supply port and a third supply port, respectively.

A side feeder is preferably installed after the second supply port. This is because the use of the side feeder makes it possible to stably supply the material even when the component sent from the upstream side is strongly compressed. The side feeder is preferably a twin-screw type that does not generate shear heat.

Further, the barrel block portion on which the side feeder is installed, or 1 or 2 of the barrel block.
In the barrel block (upstream side) before the block,
It is preferable to provide an open hole or a degassing vent. This is because it is possible to discharge the air supplied into the extruder cylinder together with the raw material B through the opening hole or the degassing vent, to make the supply of the raw material smooth, and to prevent oxidative deterioration of the resin component and the burn. is there.

In the present invention, degassing from the degassing vent can be carried out as necessary, but degassing is more preferred. A vacuum pump is generally used for degassing from the degassing vent, but it is not particularly limited as long as it is a degassing device. By performing such deaeration, it becomes possible to remove water contained in the raw material, volatile gas generated from the raw material, and the like. The degassing vent may be provided in two or more places, and in the present invention, it is preferable that the degassing vent is also provided in two or more places because it has two or more supply ports. For example, after the raw material supplied from the first supply port is melt-kneaded, a first degassing vent is provided to remove water contained in the raw material and volatile gas generated, and then the raw materials B and C are supplied. A method of removing the water content and the generated volatile gas from the second degassing vent after being melt-kneaded is preferable. Such a method is particularly suitable when the raw material B or the raw material C is mixed with the raw material A to cause hydrolysis in any of the raw materials.

In the present invention, it is also possible to install a screen for removing the mixed foreign matter in the zone in front of the extruder die part to remove the foreign matter from the recycled resin. Such screens include wire mesh, screen changers, sintered metal plates (disk filters, etc.)
And so on.

The thermoplastic resin composition of the present invention comprises a thermoplastic resin and various additives. Examples of the additive include reinforcing filler, impact modifier, flame retardant, flame retardant aid, anti-drip agent, release agent, antioxidant, ultraviolet absorber, light stabilizer, antistatic agent, sliding agent. , Plasticizer, dispersant,
Examples include dyes and pigments, light diffusers, optical brighteners, and various other inorganic and organic fillers.

In the present invention, the raw material A supplied to the first supply port is composed of at least one kind of thermoplastic resin, and optionally contains other additives. When the raw material A is composed of two or more kinds, the supply can be performed by any of the following methods. That is, (i) a method of independently supplying all raw materials to the first supply port, (ii) a method of premixing all raw materials and supplying to the first supply port, and (iii) premixing some raw materials. However, it is a method of supplying to the first supply port independently of other raw materials. Usually, the raw material A is preferably composed of a thermoplastic resin which is a main component in the thermoplastic resin composition.

Examples of the thermoplastic resin include polyethylene resin, polypropylene resin, polystyrene resin, and H resin.
IPS resin, MS resin, ABS resin, AS resin, AES
Resin, ASA resin, SMA resin, poly-4-methylpentene-1, phenoxy resin, acrylic resin, polyphenylene ether resin, polyacetal resin, aromatic polycarbonate resin, aromatic polyester resin, aliphatic polyester resin, polyamide resin, cyclic Examples thereof include polyolefin resin, hydrogenated polystyrene resin, polyarylate resin (amorphous polyarylate, liquid crystal polyarylate), polyetheretherketone, polyetherimide, polysulfone, polyethersulfone, polyphenylenesulfide, and the like. Further, various thermoplastic elastomers can also be used. (Here, M
S resin is a copolymer mainly composed of methylmethacrylate and styrene, AES resin is a copolymer mainly composed of acrylonitrile, ethylene-propylene rubber and styrene, and ASA resin is a copolymer mainly composed of acrylonitrile, styrene and acrylic rubber. , MAS resin is a copolymer mainly composed of methyl methacrylate, acrylic rubber and styrene, and SMA resin is a copolymer mainly composed of styrene and maleic anhydride (MA). ) These thermoplastic resins can also be mixed and used.
When the raw material A contains two or more types of thermoplastic resins and other additives, even if these components are independent components, they take the form of a composition which has been previously integrated by melt kneading or the like. It may be one. The type and form of the thermoplastic resin can be appropriately selected according to the purpose of use of the composition.

Further, as the component A, not only a virgin thermoplastic resin raw material but also a crushed product of a molded product can be used. Here, "crushed product of molded product" means that the molded product is used in the market as a part of the product, the consumer has finished the usage period of the product, and the recovered product is a crushed product, before being put on the market. Defective products and sprues that occur during the molding process of
It refers to a molded product that accompanies the molding process such as a runner, a defective product in the commercialization process, and a crushed product of a molded product such as a molded product that is no longer needed as an inventory and that is processed at least once from a virgin pellet. The bulk density of the raw material A is 0.5
The range of 0.8 (g / cm ³ ) is preferable.

In the present invention, the raw material B and the raw material C which are simultaneously charged into one of the second and subsequent supply ports will be described. It is preferable that the raw material B and the raw material C are all supplied to one supply port, but it is also possible to supply them at two or more supply ports so as to satisfy the conditions of the present invention. The raw materials B and C of the present invention satisfy the conditions of the following formulas (1) and (2). 0.1 ≦ (bx / by) <0.3 (1) 0.5 ≦ (cx / cy) ≦ 1 (2) (where, bx is the bulk density (g / cm ³ ) of the raw material B, b
y is the true density of the raw material B (g / cm ³ ), cx is the bulk density of the raw material C (g / cm ³ ), and cy is the true density of the raw material C (g / c ³ ).
m ³ ))

The bulk density in the above formulas (1) and (2) can be measured by a method of dropping the raw material powder particles from a funnel under a certain condition into a certain container and packing. The true density may be measured by immersing the granular material in a liquid and measuring it from the volume of the liquid removed. The present invention combines a raw material having a high dryness satisfying the above formula (1) with a raw material satisfying the above formula (2) and supplying the raw material to the feed port of the extruder, thereby depositing or feeding to the hopper on the feed port. Improves bite in the mouth (side feeder).

In particular, from the viewpoint that the effects of the present invention are sufficiently exhibited, the raw material B preferably satisfies the following formula (4), and more preferably satisfies the following formula (5):
In particular, those satisfying the following formula (6) are preferable. 0.1 ≦ (bx / by) ≦ 0.2 (4) 0.1 ≦ (bx / by) ≦ 0.17 (5) 0.1 ≦ (bx / by) ≦ 0.15 (6) (here Where bx is the bulk density (g / cm ³ ) of raw material B, b
y represents the true density (g / cm ³ ) of raw material B)

The component of the raw material B of the present invention is not particularly limited as long as it satisfies the above formula (1), but various inorganic fillers mixed without melting in the thermoplastic resin and Organic fillers are preferred. This is because these are preliminarily processed into a fine shape because they are mixed with the thermoplastic resin, and many of them are bulky. Typical examples are reinforced fillers made of various inorganic materials and heat-resistant organic materials. Of these, fibrous or needle-shaped fillers are preferable. As the fibrous or needle-like filler, wollastonite, glass fiber chopped strands, carbon fiber chopped strands, potassium titanate whiskers, aluminum borate whiskers, titanium oxide whiskers, zinc oxide whiskers, calcium carbonate whiskers and basic sulfuric acid Various synthetic whiskers such as magnesium whiskers,
In addition, inorganic fillers obtained from natural inorganic minerals such as sepiolite, xonotlite, dawsonite, franklin fibers, and rockwool, and heat-resistant organic fibers such as aramid fibers and polyarylate fibers can be mentioned.

Generally, the higher the aspect ratio, the higher the bulk tends to be, and among the above, the aspect ratio L / D
Is preferably 3 or more, and more preferably L / D is 5 or more, because the effects of the present invention can be further exhibited. A high L / D is also advantageous in terms of reinforcing effect. Upper limit L
When / D is high, there is no particular limitation because destruction occurs during melt-kneading with the resin, but considering the supply to the extruder, the total length is preferably 10 mm or less.

Among the above, more preferred in the present invention are fibrous or needle-like inorganic fillers obtained by crushing natural minerals and inorganic fillers synthesized as whiskers. This is because such a filler is often difficult to be bound, such as glass fiber or carbon fiber, and therefore often satisfies the condition of the raw material B in many cases. Further, wollastonite can be mentioned as a particularly preferable embodiment as the raw material B of the present invention. This is because wollastonite tends to be bulky because it has a needle-like shape with an extremely small diameter (1 to several μm), and has a good effect of reinforcing the resin. In recent years, wollastonite having a smaller diameter has been manufactured. The true density and bulk density of the inorganic filler are J
It is determined by a method according to IS K5101.

As the raw material C of the present invention, those satisfying the following formula (7) are preferable, and those satisfying the following formula (8) are more preferable. 0.55 ≦ (cx / cy) ≦ 0.9 (7) 0.6 ≦ (cx / cy) ≦ 0.8 (8) (where cx is the bulk density (g / cm ³ ) of the raw material C, c
y represents the true density (g / cm ³ ) of raw material C)

The component of the raw material C of the present invention is not particularly limited as long as it satisfies the above formula (2), but more preferable is a thermoplastic resin powder, particularly a pellet. The shape of the pellet can be various shapes such as a cylindrical shape, a spherical shape, and a plate shape. The size of the pellet may be any size that can be normally used as a pellet,
The diameter and length are preferably 1 to 9 mm, preferably 2 to 6 mm, more preferably 2 to 4 mm. If the size is too small, the condition of the above formula (2) may not be sufficiently satisfied, and if it is too large, the pellets may not be bite well.

The bulk density of the thermoplastic resin powder material in the raw material C can be determined by the method according to JIS K7365, while the true density is JIS K7112.
It can be determined from a sample that has been heat-processed into the shape of a molded product by a method according to

The thermoplastic resin in the raw material C may be the same as, the same as or different from the thermoplastic resin in the raw material A. Among them, in a particularly preferable embodiment, the thermoplastic resin composition is composed of two or more kinds of resin components, and the thermoplastic resin raw material which is the main component of the thermoplastic resin composition is supplied as the raw material A to the first supply port of the extruder to be the auxiliary component. This is a manufacturing method in which pellets of another thermoplastic resin are supplied as the raw material C to the second and subsequent supply ports of the extruder. Further, in the same type of thermoplastic resin, it is possible to use a powder-shaped raw material as the raw material A and a pellet-shaped raw material as the raw material C. As the thermoplastic resin, for example, various kinds of resins exemplified in the description of the raw material A can be used.

As the raw material C, as in the case of the raw material A, not only the virgin raw material but also a crushed product of a molded product can be used. Further, the raw material C may be not only a single resin component but also a mixture of two or more components. That is, it is possible to use a mixture of two or more thermoplastic resin pellets or powders. Further, it is also possible to use a composition in which two or more resin components are melt-kneaded in advance.

The present invention is characterized in that the raw material B and the raw material C are simultaneously supplied at the second supply port or the supply port downstream thereof, and the supply ratio thereof satisfies the following expression (3). Ranges are preferred. bs / (bs + cs) ≦ 0.9 (3) (where, bs is the feed rate (kg / h) of the raw material B to the extruder feed port, and cs is the feed rate of the raw material C to the extruder feed port (kg) / H))

The value of the upper limit of 0.9 in the above formula (3) is more preferably 0.8, further preferably 0.7, and particularly preferably 0.6. On the other hand, the lower limit of bs / (bs + cs) is not particularly limited and is determined by the ratio of raw material B and raw material C. As will be described later, the raw material B is preferably 0.5% by weight or more in the composition, and the raw material C is 5% by weight in the composition.
Since 0% by weight or less is preferable, bs / (bs + c
A preferable value for the lower limit of s) is 0.01.

The thermoplastic resin composition of the present invention contains 30 to 98% of the raw material A as a component in 100% by weight of the composition.
It is preferable that 5% by weight, 0.5 to 50% by weight of raw material B as a component, and 1 to 50% by weight of raw material C as a component. More preferably 100% by weight of the composition
40 to 98% by weight of raw material A as a component, raw material B
1 to 30% by weight as a component, and 1 to 30% by weight of a raw material C as a component, more preferably 50 to 94% by weight of a raw material A as a component in 100% by weight of the composition. The raw material B contains 3 to 25 wt% as its component, and the raw material C contains 3 to 30 wt% as its component. The thermoplastic resin composition of the present invention may contain raw materials other than the above raw materials A to C, and 100% by weight of the above composition means the ratio based on the total weight of the composition including those raw materials. .

A particularly preferred embodiment of the present invention will be described. The effect of the present invention becomes more remarkable as the processing temperature is higher. This is because the higher the temperature is, the more easily the thermal decomposition of the resin due to variations in the supply of raw materials and the entrainment of air. Furthermore, when the thermoplastic resin decomposes not only by radical thermal decomposition but also by hydrolysis, it is significantly affected by high temperature. Conversely, the production method of the present invention can be preferably applied to a resin having a higher processing temperature and more susceptible to hydrolysis. From this point, as the raw material A of the present invention,
Aromatic polycarbonate resin, polyarylate resin, aromatic polyester resin, polyamide resin and the like are preferable, and aromatic polycarbonate resin is particularly preferable.

For the same reason as described above, as the raw material B, a raw material that easily promotes hydrolysis of the resin is preferable in that the effect of the present invention can be exhibited more effectively. As such a raw material, an inorganic filler obtained from a natural mineral is used. Examples of the material include fine materials having a large surface area. Also from this point, wollastonite is suitable as the raw material B of the present invention.

Therefore, as the raw material C, ABS resin, AS resin, aromatic polyester resin, polyarylate resin and the like, which are frequently mixed with the aromatic polycarbonate resin, are more preferable. Of these, aromatic polyester resins are particularly suitable. This is because the resin is likely to deteriorate during melt-kneading due to the transesterification reaction with the aromatic polycarbonate resin.

From the above, in the present invention, it is preferable that the raw material A is mainly composed of an aromatic polycarbonate resin, the raw material B is wollastonite, and the raw material C is a pellet of an aromatic polyester resin. Can be mentioned. That is, according to the present invention, in a method for producing a resin composition comprising an aromatic polycarbonate resin, an aromatic polyester resin, and wollastonite, which is likely to deteriorate due to the conditions of its melt-kneading, by stable supply of wollastonite Provided is a manufacturing method which suppresses thermal deterioration and hydrolysis during melt-kneading as much as possible, and enables stable and favorable production of a resin composition even in continuous production for a long time.

In this preferred embodiment, the aromatic polycarbonate resin and aromatic polyester resin preferably have a low water content. Therefore, it is preferable to dry either the aromatic polycarbonate resin or the aromatic polyester resin, and it is particularly preferable to dry at least the aromatic polyester resin. Examples of the drying means include various means such as hot air drying, electromagnetic wave drying, and vacuum drying.

Further, it is preferable to perform the deaeration vent after the aromatic polycarbonate resin, wollastonite and aromatic polyester resin are mixed, without raising the degree of vacuum so much. More preferably, the method is performed at a degree of vacuum close to atmospheric pressure. Further, it is possible to use a method of discharging volatile components to the outside of the system while circulating nitrogen gas or the like.

In the production method of the present invention, the above raw material A,
It is also possible to appropriately supply components other than the raw material B and the raw material C through a predetermined supply port. In this case, when it is necessary to directly supply the liquid raw material to the extruder, a so-called liquid injection device or liquid addition device can be used for the supply.

Since the thermoplastic resin composition obtained by the production method of the present invention is produced by the stable supply of the raw materials even for a long time, the quality becomes extremely stable. Therefore, a large number of products are produced and the quality stability is strict, for example, a field requiring high fatigue strength such as a vehicle outer handle, a field requiring high impact resistance such as a housing of a laptop computer, and This is a very suitable manufacturing method for manufacturing resin materials in fields requiring high dimensional accuracy and strength such as camera parts.

[0049]

BEST MODE FOR CARRYING OUT THE INVENTION 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.

(Examples 1 to 3 and Comparative Examples 1 to 5) (1) Content of Filler in Pellet Every hour when a reinforced thermoplastic resin composition is produced by the production method shown in each example below. The amount of the filler contained in the pellets was measured for a total of 11 points of the samples sampled in 1. For Example 1 and Comparative Examples 1 and 2, a TGA device (TA-Instruments Hi-Res TGA2950 Thermogr) was used.
avimetric Analyzer),
A sample amount of 30 mg was heated from room temperature to 500 ° C. at 20 ° C. for 1 minute in an air atmosphere, and after the temperature in the furnace reached 500 ° C., the temperature was maintained for 1 hour, after which the residue content remained without combustion and vaporization. Was calculated as the filler content. For Examples 2-3 and Comparative Examples 3-5, 3 g of pellets were placed in a crucible and heated and incinerated in an electric furnace at 600 ° C. for 3 hours.
The residue was calculated as the filler content. The average value and standard deviation (σ) of the calculated filler content were calculated. The results are shown in Table 3 together with the maximum value and the minimum value out of 11 points.

(2) Measurement of Flexural Modulus of Molded Article After uniformly mixing the sampling pellets obtained above for each time period, 120 ° C. × 5 hours for Examples 1 and 2 and Comparative Examples 1 to 4 Examples 3 and 4 and Comparative Example 5 were dried at 110 ° C. for 5 hours. An injection molding machine (Sumitomo Heavy Industries, Ltd .; S480 /
150 (mold clamping pressure 150 ton))
Also, Comparative Examples 1 to 3 have a cylinder temperature of 300 ° C. and a mold temperature of 90 ° C., and Example 2 and Comparative Example 4 have a cylinder temperature of 28.
At 0 ° C. and a mold temperature of 80 ° C., Examples 4 and 5 and Comparative Example 5 are a cylinder temperature of 270 ° C. and a mold temperature of 70 ° C.
Test pieces according to O178 were molded. 12 in total
Shots were performed and 6th to 10th shots were taken as test pieces. The flexural modulus of the obtained test piece was measured according to ISO 178. Five measurements were performed for each of 11 samples at each time, and the average value and standard deviation (σ) of all the samples (55 points in total) were calculated. The results are shown in Table 3 together with the maximum and minimum values among 55 points.

(3) Measurement of MVR value Pellets in the time samples of Examples 2 and 3 and Comparative Examples 4 and 5, and 11 obtained by the molding of (2) above.
And the MVR value of the molded article at the 12th shot was measured. The measurement was performed according to ISO1133. The sample of the molded product was cut into almost the same size as the pellet using a nipper to obtain a sample for measurement, and dried by hot air under the same conditions as in the above (2) for measurement. The average value and the maximum value in the pellet and the molded product, and the maximum value of the difference between the pellet and the molded product at each time were obtained. The results are shown in Table 3.
Shown in. Next, the production of samples in each example will be described. The description will be given based on the following abbreviations.

Example 1 PC-1, FR as raw material A
-1, ST-1, and Col-1 were uniformly mixed with a Nauta mixer so that the proportions shown in Table 1 were obtained. Such a mixture was fed by an automatic feeder to a screw feeder with a weighing machine (Kubota's twin-screw cassette weigh feeder NT-CWF (model: CE-T-II,
Agitator: vertical standard)), and a predetermined amount was supplied from the feeder to the first supply port of the extruder so that the ratio was as shown in Table 1. Further, the automatic feeder was set so as to feed the raw material up to about 90% by weight when it reached about 30% by weight based on the total capacity of the hopper of the feeder. On the other hand, CF, which is the raw material B of the present invention, is a screw type feeder with a weighing machine (2-axis screw type cassette weighing feeder made by Kubota Co., Ltd. wide range CWF (model:
CE-W-I)) was used and fed to the side feeder connected to the second feeding port of the extruder in the proportions shown in Table 1. Furthermore, PC-4 which is the raw material C of the present invention
Is a vibrator feeder with a weighing machine (Kubota's vibrating cassette weighing feeder CWF (model:
CE-FI) was used and fed to the side feeder connected to the second feeding port of the extruder so that the ratio was the same as that of CF as shown in Table 1. Each cassette weighing feeder has a gravimetric quantitative supply controller (KF-C8 manufactured by Kubota).
8 controllers) and set the supply amount. The extruder has a vented twin-screw extruder (made by Japan Steel Works: TEX44
HCT-31.5AW-2V) was used. As extrusion conditions, the cylinder temperature is 290 ° C and the screw rotation speed is 150.
rpm, vent suction (3kPa), discharge rate 100k
Extrusion was performed under the conditions of g / hr. After the strand was cooled in the bath, pellets were obtained by a pelletizer. The first
There was a first kneading zone between the supply port and the second supply port, an open hole was provided in the barrel above the side feeder, and a second kneading zone was provided after the second supply port. All the second kneading zones consisted of a set of 5 segments of 45 ° phase (forward direction). The degassing vent was provided after the kneading zone. Extrusion was carried out by purging in the extruder for a few minutes from the start of extrusion without stranding, and then stranding was performed as described above for about 10 hours to obtain pellets. Sampling from the time of pellet production,
After that, a total of 11 points were sampled every hour.

(Comparative Example 1) Example 1 is the same as Example 1 except that PC-4, which is the raw material C, was not used, and the aromatic polycarbonate resin corresponding to that was supplied as PC-1 from the first supply port. Prepared as in 1.

(Comparative Example 2) The procedure of Example 1 was repeated, except that the raw material C, PC-4, was replaced with PC-5.

(Comparative Example 3) Comparative Example 1 was prepared in the same manner as Comparative Example 1 except that CS (a filler not satisfying the formula (1) of the present invention) was used in place of CF which was the raw material B. .

(Example 2) A second example was manufactured in the same manner as in Example 1 except that the following points were changed. That is, PC-3, IM-1, and PTFE having the proportions shown in Table 2 as raw material A
A mixture of -1, WAX, ST-2, and Col-2 was used. WSN-1 was used as the raw material B. As raw material C, PBT and PET were used. In addition, PBT
And PET were each dried by a hopper dryer to have a water content of 0.02% by weight, and the supply was independently performed using two vibrator type feeders with a measuring device. The cylinder temperature of the extruder was 280 ° C. and the vent suction degree was 50 kPa. A kneading zone between the first supply port and the second supply port, and a degassing vent between the second supply port were further provided, and suction was performed at a vacuum degree of 3 kPa.

(Comparative Example 4) In the above-mentioned Example 2, the PBT and PET of the raw material C were not used, but PBT / PET
It was manufactured in the same manner as in Example 2 except that the mixture of PET was supplied from the first supply port.

(Example 3) The same procedure as in Example 1 was repeated except that the following points were changed. That is, PC-2, IM-2, FR- having the proportions shown in Table 2 as the raw material A
2, PTFE-2, WAX, ST-3, and Col-
A mixture of 3 was used. WSN-2 was used as the raw material B. ABS-1 was used as the raw material C. Extruder cylinder temperature 260 ℃, vent suction degree 3kP
a.

(Comparative Example 5) A material was manufactured in the same manner as in Example 3 except that the raw material C, ABS-1, was all mixed in the raw material A.

The contents of various raw materials shown in Tables 1 and 2 are as follows. PC-1: Bisphenol A type aromatic polycarbonate resin powder with viscosity average molecular weight 22,500 (Teijin Kasei: Panlite L-1225WP) PC-2: Bisphenol A type aromatic polycarbonate resin powder with viscosity average molecular weight 19,700 ( Teijin Chemicals: Panlite L-1225WX) (iii) PC-3: Bisphenol A type aromatic polycarbonate resin powder with a viscosity average molecular weight of 25,000 (Teijin Kasei: Panlite L-1250WQ) PC-4: Viscosity average molecular weight 19,50 with 0.78 g / cm ³ and true density of 1.20 g / cm ^3.
0 of bisphenol A type aromatic polycarbonate resin pellets (Teijin Chemicals Ltd., Panlite L-1225L) PC-5: viscosity average molecular weight 30 bulk density 0.56 g / cm ³ and a true density of 1.20 g / cm ³ , 00
0 bisphenol A type aromatic polycarbonate resin powder (Sanyosha Novalex 7030PJ)

ABS-1: The bulk density is 0.70 g / cm.
³ and ABS resin pellets manufactured by the bulk polymerization method having a true density of 1.02 g / cm ³ (manufactured by Japan A & L:
Santak UT-61) ABS-2: ABS resin powder (manufactured by Ube Saikon:
UCL Modifier Resin B601N)

[0063] PBT: bulk density 0.7 g / cm ³ and a true density of 1.31 g / cm ³ polybutylene terephthalate resin pellets (from Teijin Ltd.: TRB-H) PET: bulk density 0.79g / Cm ³ and polyethylene terephthalate resin pellets having a true density of 1.33 g / cm ³ (manufactured by Teijin Ltd .: TR-8580H) PBT / PET: The above PBT and PET are uniform at a ratio of 5/1 (weight ratio). Mixed pellet mixture

CF: Chopped strand of carbon fiber having a bulk density of 0.32 g / cm ³ and a true density of 1.77 g / cm ³ (manufactured by Toho Tenax Co., Ltd .: Vesphite H)
TA-C6-U) WSN- 1: bulk density 0.4 g / cm ³ and a true density of 2.91 g / cm ³ wollastonite (Nai co Minerals Corporation: NYGLOS4) WSN-2: bulk density 0.4 g / cm ³ and a true density of 2.91 g / cm ³ wollastonite (Kawatetsu mining Co.: PH450) CS: bulk density 0.81 g / cm ³ and a true density of 2.54 g / cm ³ Glass fiber chopped strand (3PE937FB manufactured by Nitto Boseki Co., Ltd.)

IM-1: Impact modifier (a graft copolymer obtained by grafting methyl methacrylate on a composite elastic body of a polyorganosiloxane rubber component and a polyalkyl (meth) acrylate rubber component, manufactured by Mitsubishi Rayon: Metablen S-2001 IM-2: Impact modifier (2-ethylhexyl acrylate / butadiene / methyl methacrylate / styrene multi-stage graft copolymer, manufactured by Kureha Chemical Industry: HIA-15)

FR-1: 90% by weight of the above PC-1 and a flame retardant (potassium perfluoro n-butanesulfonate, manufactured by Dainippon Ink and Chemicals; Megafac F-114P): 1
Pre-kneaded product FR-2 mixed with 0% by weight with a super mixer: Flame retardant (resorcinol bis (dixylenyl phosphate), manufactured by Asahi Denka Kogyo: ADEKA STAB FP-
500)

PTFE-1: Melt property modifier (a mixture of polytetrafluoroethylene having an ability to form fibrils and an acrylonitrile-styrene copolymer, manufactured by GS Specialty Chemicals: BLENDEX B4
49) PTFE-2: the above PC-2: 97.5% by weight and an anti-drip agent during combustion (polytetrafluoroethylene having a fibril forming ability, manufactured by Daikin Industries, Ltd .: Polyflon M)
PA FA500): premix with 2.5% by weight

WAX: Adhesion inhibitor for filler (copolymer of maleic anhydride and α-olefin, manufactured by Mitsubishi Chemical Corporation:
Diacarna PA30M) SL: Release agent (saturated fatty acid triester of glycerin,
And a mixture of esters of higher alcohols and saturated fatty acids, Riken Vitamin Co., Ltd .: Rikemar SL-900)

ST-1: 90% by weight of the above PC-1 and a phosphate stabilizer (manufactured by Daihachi Chemical Industry Co., Ltd .: TMP): 1
Pre-kneaded product ST-2 mixed with 0% by weight with a super mixer: PC-3: 89% by weight, phosphite-based stabilizer (Asahi Denka Kogyo KK; ADEKA STAB PEP-8):
10% by weight, and a phosphate-based stabilizer (manufactured by Daihachi Chemical Industry Co., Ltd .: TMP): 1% by weight, a preliminary kneaded product ST-3: the above PC-2: 87.5% by weight, a stabilizer (Asahi Denka Kogyo KK; ADEKA STAB AO-18): 7.5% by weight, and a phosphate stabilizer (manufactured by Daihachi Chemical Industry:
TMP): 5% by weight of a premixed product mixed with a super mixer

Col-1: viscosity average molecular weight 16,000
70% by weight of aromatic polycarbonate resin, carbon black (manufactured by Mitsubishi Chemical Corporation: carbon black MA-10
0) 20% by weight and polyethylene wax (manufactured by Mitsui Chemicals, Inc .: Hiwax # 405MP) 10% by weight are melt-kneaded to form a carbon black master pellet Col-2: the following dyes, pigments and PC-3.
A dry color master mixture in which and are evenly mixed with a super mixer. Weight% is the total amount of Col-2 100% by weight
The ratio is shown. PC-3: 74.875% by weight, titanium oxide (manufactured by Thai Oxide Japan: Tioxide R-TC3)
0): 25% by weight, carbon black (manufactured by Mitsubishi Chemical Corporation: carbon black # 970): 0.125% by weight Col-3: the following dyes, pigments, and PC-2
A dry color master mixture in which and are evenly mixed with a super mixer. % By weight is the total amount of Col-3 100% by weight
The ratio is shown. PC-2: 65.6067% by weight, titanium oxide (manufactured by Thai Oxide Japan Co .: Ti
oxide R-TC30): 33.3333% by weight,
Carbon black (manufactured by Mitsubishi Chemical: carbon black # 970): 0.6933% by weight, yellow dye (manufactured by Arimoto Chemical Co., Ltd., Plast Yellow 8010): 0.200
0% by weight, red dye (produced by Arimoto Chemical Industry Co., Ltd., Plast Red 8360): 0.1667% by weight

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

As is clear from the comparison between these examples and the corresponding comparative examples, when a fibrous or needle-shaped filler having a low bulk density is supplied from the side feeder, a part of the thermoplastic resin composition is used. When the pellets are simultaneously supplied from the side feeder, it is possible to obtain a reinforced thermoplastic resin composition with a small variation in the filler content, but a fibrous or needle-shaped filler having a low bulk density is used as the side feeder. If the resin composition is supplied alone, the content of the filler in the resin composition varies, and the strength, rigidity and dimensional accuracy of the molded product vary greatly. Especially, the effect is great when manufacturing thin parts or minute parts.

[0075]

EFFECTS OF THE INVENTION When a thermoplastic resin composition containing a fibrous or needle-shaped filler having a low bulk density is produced by the production method of the present invention, a reinforced thermoplastic resin composition having a small variation in the filler content is obtained. Can be obtained. The final reinforced thermoplastic resin molded product produced by using this reinforced thermoplastic resin composition has excellent rigidity, strength and dimensional accuracy, and is suitable for a wide range of applications such as electric / electronic parts, mechanical parts, OA parts, automobile parts, and medical parts. It can be used.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 101/00 C08L 101/00 // B29K 101: 12 B29K 101: 12 105: 16 105: 16 F term (reference) 4F070 AA47 AA50 AA71 AB11 AC22 AD10 AE01 FA01 FA03 FA17 FB06 FC05 4F201 AA24 AA27 AA28 AB11 AB16 AH17 AH33 AH53 AH63 AR15 AR20 BA01 BC01 BC12 BC37 BK02 CF75 CF75 CF03 CF75 CF03 CF05 CF03 CF05 CF03 BK74 CF03 BQ04 CF03 BQ04 CF03 BQ04 CF03 BQ04 CF03 BQ04 CF03 BQ04 CF03 CG01W CG01X CG011 DA016 DA037 DJ006 EV257 EW047 FA046 FD016 FD037 FD098 FD137

Claims (6)

[Claims] 1. A method for producing a thermoplastic resin composition by melt-kneading a bulky raw material and a thermoplastic resin using an extruder, wherein the extruder has two or more supply ports, A raw material (raw material A) containing a thermoplastic resin is supplied to the first supply port which is the most upstream and melted, and one supply port on the downstream side of the first supply port satisfies the following formula (1). A thermoplastic resin composition characterized in that a raw material (raw material B) having a high dryness and another raw material (raw material C) satisfying the following formula (2) are simultaneously supplied and melt-kneaded with a melt of the raw material A. Production method. 0.1 ≦ (bx / by) <0.3 (1) 0.5 ≦ (cx / cy) ≦ 1 (2) (where, bx is the bulk density (g / cm ³ ) of the raw material B, b
y is the true density of the raw material B (g / cm ³ ), cx is the bulk density of the raw material C (g / cm ³ ), and cy is the true density of the raw material C (g / c ³ ).
m ³ )) 2. The method for producing a thermoplastic resin composition according to claim 1, wherein the feed of the raw materials B and C to the extruder satisfies the following formula (3). bs / (bs + cs) ≦ 0.9 (3) (where, bs is the feed rate (kg / h) of the raw material B to the extruder feed port, and cs is the feed rate of the raw material C to the extruder feed port (kg) / H)) 3. The thermoplastic resin composition is the composition 1 described above.
30 to 98.5 with the raw material A as its component in 100% by weight.
% By weight, 0.5 to 50% by weight of raw material B as its component,
3. The method for producing a thermoplastic resin composition according to claim 1, wherein the raw material C is contained as a component in an amount of 1 to 50% by weight. 4. The method for producing a thermoplastic resin composition according to claim 1, wherein the raw material B is wollastonite. 5. The method for producing a thermoplastic resin composition according to claim 1, wherein the raw material C is a pellet of a thermoplastic resin. 6. The raw material A is mainly composed of an aromatic polycarbonate resin, the raw material B is wollastonite, and the raw material C is a pellet of an aromatic polyester resin. The method for producing the thermoplastic resin composition according to item 1.