JPH09220719A - Fiber reinforced thermoplastic resin pellet aggregate, its manufacture, and fiber reinforced thermoplastic resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber reinforced thermoplastic resin aggregate of high rigidity in which the dispersion of a fiber content among pellets is low in spite of a high fiber content, its manufacturing method, and a molding made by the method. SOLUTION: In a resin pellet aggregate, an average fiber content Wa is 45-80wt.%, the fiber content of each pellet to an average fiber content Wa is in a range of ±0.03×Wa, and a ratio Lw/Ln between weight average fiber length Lw of reinforcing fibers and average fiber length Ln in each pellet is 1.1 or more. Moreover, the flexural strength measured by ASTM D-790 is 20GPa or more.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fiber-reinforced thermoplastic resin pellet aggregate having a high fiber content and a small variation in the fiber content of each pellet, a method for producing the same, and a fiber-reinforced thermoplastic resin obtained from the aggregate. Regarding resin molded products.

[0002]

2. Description of the Related Art Conventionally, a method for producing fiber-reinforced thermoplastic resin pellets, which is a raw material for molded articles, is such that a thermoplastic resin melted by an extruder is extruded into a gut shape while kneading chopped strands, and the gut is cut shortly. The most general method is to pelletize (Japanese Patent Publication No. 41-20738). In addition, in order to improve the mechanical properties of molded products, as a method for producing fiber-reinforced thermoplastic resin pellets in which reinforcing fibers are made into long fibers, a pull-through method (pultrusion molding method) in which continuous reinforcing fibers are coated with molten thermoplastic resin Is known (Japanese Patent Publication No. 63-37694).

On the other hand, in order to further improve the mechanical properties of the molded product, the fiber content of the reinforcing fiber may be increased. However, in the case of producing a fiber-reinforced thermoplastic resin pellet having a fiber content increased to 45% by weight or more,
In the former method, strong kneading must be added in order to uniformly disperse a large amount of reinforcing fibers in the molten resin, but shearing heat generation increases due to strong kneading, so the resin deteriorates due to heat, and the physical properties deteriorate on the contrary. There was a problem.

Further, in the latter pultrusion method, continuous reinforcing fibers are extracted and pelletized while impregnating the resin, so that the fiber length in the pellet is constant (Lw / Ln = 1), but the productivity is poor, Moreover, there is a drawback that the fiber cannot be sufficiently impregnated unless the resin has a low viscosity. Further, since the continuous reinforcing fibers are present in the pellet in a bundled state, there is a problem that the fluidity in injection molding is poor and the dispersion of the fibers in the molded product becomes insufficient. As a result, it was extremely difficult to improve both the elastic modulus and the impact strength of the molded product at the same time.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems of the prior art, to improve the fiber content, to improve the fiber content of each pellet with a small variation in the fiber content, and to provide a fiber reinforced material having an excellent elastic modulus. It is intended to provide a thermoplastic resin pellet aggregate, a method for producing the same, and a molded article made of the same. Another object of the present invention is to provide a fiber-reinforced thermoplastic resin pellet aggregate having both increased elastic modulus and impact strength, a method for producing the same, and a molded article comprising the same.

[0006]

That is, the present invention provides:
(1) An aggregate of fiber reinforced thermoplastic resin pellets, wherein an average fiber content Wa of 10 g of pellet aggregates arbitrarily collected is 45 to 80% by weight, and the fiber content of each pellet is the average. Fiber content Wa ±
Within the range of 0.03 × Wa, and the ratio L of the weight average fiber length Lw and the number average fiber length Ln of the reinforcing fibers in each pellet.
w / Ln is 1.1 or more, and ASTM D-790
Flexural modulus is 20GP when measured based on the regulations
a fiber-reinforced thermoplastic resin pellet aggregate having a or more,
(2) An aggregate of fiber-reinforced thermoplastic resin pellets, wherein the arbitrarily collected pellet aggregate 10 g has an average fiber content Wa of 45 to 80% by weight, and the fiber content of each pellet is the average. Fiber content Wa ±
The pellets within the range of 0.03 × Wa account for 90% by weight or more of the pellet aggregate 10 g, and the ratio Lw / the weight average fiber length Lw and the number average fiber length Ln of the reinforcing fibers in each pellet. Ln is 1.1 or more, and ASTM
A fiber reinforced thermoplastic resin pellet aggregate having a flexural modulus of 20 GPa or more when measured based on the regulations of D-790, (3) The average fiber content Wa is 60 to 80% by weight (1). Alternatively, the fiber-reinforced thermoplastic resin pellet aggregate according to (2), (4) the fiber-reinforced thermoplastic resin pellet aggregate according to any one of (1) to (3) above, wherein the reinforcing fibers are glass fibers. ) ASTM D-
The Izod impact strength with notch when measured according to the provisions of 256 is 170 J / m or more (1) to
The pellet aggregate according to any one of (4).

The present invention also provides (6) an extruder having a cylinder and a screw,
Alternatively, at least a part of the screw is provided with a control mechanism part having a modified surface, and an extruder having a straightening plate arranged between the screw tip and the die is used to melt the thermoplastic resin, The fiber-reinforced heat according to any one of (1) to (5) above, wherein continuous reinforcing fibers occupying 80% by weight are supplied, kneaded by the control mechanism section, extruded through the flow straightening plate and pelletized. A method for producing a fiber-reinforced thermoplastic resin pellet aggregate, which comprises producing a plastic resin pellet aggregate, (7) the extruder is a multi-screw type, and the extruder has a resin supply port and a fiber supply port. And a method for producing a fiber-reinforced thermoplastic resin pellet aggregate according to the above (6), wherein the reinforcing fiber supply port is arranged on the downstream side of the resin supply port.
The method for producing a fiber-reinforced thermoplastic resin pellet aggregate according to the above (6) or (7), wherein the deforming is unevenness.

Further, the present invention is (9) above (1).
A fiber-reinforced thermoplastic resin molded product obtained by molding the pellet aggregate according to any one of (5).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the fiber-reinforced thermoplastic resin pellet aggregate means an aggregate in which a plurality of individual pellets are aggregated.

The pellet aggregate of the present invention has an average fiber content Wa of 10 g of pellets arbitrarily sampled from 45 to 80% by weight, preferably 50 to 80% by weight, particularly preferably 60 to 80% by weight. %, And the fiber content of each pellet is ± with respect to the above average fiber content Wa.
Within the range of 0.03 × Wa, more preferably ± 0.02
There are variations within a narrow range of × Wa.

For example, when the average fiber content of the reinforcing fibers contained in 10 g of pellet aggregate is 60% by weight, the content of reinforcing fibers contained in each pellet is 60 ±.
That is, it is within the range of 60 × 0.03 = 60 ± 1.8% by weight.

Further, in the present invention, in order to impart various functions such as coloring and accelerating crystallization to the above pellet aggregate, modification of coloring pellets or a nucleating agent for accelerating crystallization is carried out. A pellet containing the agent can be mixed. The mixing ratio at that time is an amount that does not impair the effects of the present invention, and is usually 10% by weight or less, particularly preferably 5% by weight or less. In that case, in the pellet aggregate of the present invention, 90 wt% or more of the 10 g of the pellet aggregate arbitrarily collected has an average fiber content Wa of 45 to 80 wt%, preferably 5%.
0 to 80% by weight, particularly preferably 60 to 80% by weight, and the fiber content of each pellet is within a range of ± 0.03 × Wa with respect to the average fiber content Wa, more preferably ± 0. It varies within a narrow range of 0.02 × Wa.

In the fiber-reinforced thermoplastic resin pellet aggregate of the present invention, the ratio Lw / Ln of the weight average fiber length Lw and the number average fiber length Ln of the reinforcing fibers contained in each pellet is 1.1 or more, preferably 1 .15 or more.

When the ratio Lw / Ln of both is less than 1.1, it means that the fiber length is substantially one, that is, the fiber-reinforced thermoplastic resin pellets produced by the pultrusion method. As described above, the pellets produced by such a pultrusion method are inferior in productivity and fluidity. The upper limit of the ratio Lw / Ln of the weight average fiber length Lw and the number average fiber length Ln is not particularly limited, but is preferably 5 or less, and particularly preferably 3 or less.

In the present invention, the weight average fiber length Lw and the number average fiber length Ln are defined as follows.

[0016]

## EQU1 ## Weight average fiber length Lw = Σ (ρπr ² Li × Li) / Σ (ρπr ² Li) = ΣLi ² / ΣLi Number average fiber length Lw = ΣLi / n where ρ: density of reinforcing fiber r: reinforcement Fiber radius Li: Length of i-th reinforcing fiber n: Number of reinforcing fibers.

The weight average fiber length of the reinforcing fibers in the pellets of the present invention is preferably 0.1 mm or more and less than 10 mm, more preferably from the viewpoint of mechanical properties of the obtained molded product and dispersibility of the reinforcing fibers. It is 0.2 mm or more and less than 3 mm.

Since the fiber-reinforced thermoplastic resin pellet aggregate of the present invention contains a highly large amount of reinforcing fibers in each pellet, and the variation in the fiber content among the pellets is small, when formed into a molded product. Both the elastic modulus and the impact strength can be increased. Further, the fiber-reinforced thermoplastic resin pellet aggregate of the present invention is ASTM D-790.
The flexural modulus measured on the basis of the above-mentioned has a performance of 20 GPa or more, and a molded product obtained from it can be a molded product excellent in rigidity.

Furthermore, in many cases, the fiber-reinforced thermoplastic resin pellet aggregate of the present invention has a flexural modulus of 20 GPa or more measured according to the standard of ASTM D-790 and also according to the standard of ASTM D-256. The Izod impact strength with notch measured by the method has a performance of 170 J / M or more. Molded articles obtained from such pellet aggregates can have properties in which both rigidity and impact resistance are greatly increased.

The thermoplastic resin used in the present invention is not particularly limited as long as it can be molded.
Polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene-butadiene-acrylonitrile copolymer, nylon 11, nylon 12, aliphatic nylon such as nylon 6 and nylon 66, and aromatic nylon such as aliphatic nylon and terephthalic acid Semi-aromatic polyamide copolymerized with dicarboxylic acid or aromatic diamine, various copolymerized polyamides, polycarbonate, polyacetal, polymethylmethacrylate, polysulfone, polyphenylene oxide, polybutylene terephthalate, polyethylene terephthalate, polycyclohexane dimethylene terephthalate, polycyclohexane diethylene Polyesters such as terephthalate and polybutylene naphthalate and their copolymers, thermotropic liquid crystal polymers Polyphenylene sulfide, polyether ether ketone, polyether sulfone, polyetherimide, polyamideimide, polyimide, polyurethane, polyether amide and the like, which can be used alone or in combination of two or more.

Among these, particularly preferable resins are polyethylene, polypropylene, polybutylene terephthalate, polyethylene terephthalate, polycyclohexanedimethylene terephthalate, polyethylene terephthalate copolymer liquid crystal polymer, nylon 11, nylon 12, nylon 6, nylon 66, Semi-aromatic nylon, copolymer nylon, polyphenylene sulfide, AB
S resin.

The reinforcing fiber used in the present invention is not particularly limited as long as it is usually used for reinforcing a resin. For example, glass fibers, carbon fibers, metal fibers, and organic fibers (nylon, polyester, aramid, polyphenylene sulfide, acrylic, liquid crystal polymer, etc.) can be used. These reinforcing fibers may be used alone or in combination of two or more. Among these reinforcing fibers, glass fiber and carbon fiber are particularly preferable.

In the present invention, the fiber diameter of the reinforcing fiber is 1
˜30 μm is preferable, and further, diameter is preferably 6 to 20 μm.

The fiber-reinforced resin pellet aggregate of the present invention is
For example, in an extruder having a screw and a cylinder, a control mechanism part in which at least a part of the screw and / or the cylinder is surface-deformed is provided, and one or more straightening plates are provided in the cylinder between the screw tip and the die. Using an individually attached extruder, a thermoplastic resin is supplied to the extruder and melted, while the continuous reinforcing fiber is supplied to the molten resin so that the content in the composition becomes 45 to 80% by weight. It can be manufactured by kneading in the control mechanism part, extruding this and pelletizing.

The pellets are discharged from the extruder as a rod-shaped material having a diameter of about 1 to 8 mm and cut into small pieces having a length of about 2 to 50 mm, or a thickness of 1 to 8 m.
It is preferable to obtain a sheet-like material having a size of about m by cutting it into a strip having a side length of about 2 to 50 mm. Alternatively, the same size may be obtained by crushing what is discharged using a die having a large discharge port.

In the present invention, continuous fibers are usually used as the reinforcing fibers to be fed to the extruder, and more specifically, rovings in which continuous single fibers are bundled may be used. The number of fibers to be bundled is not particularly limited, but a bundle of 10 to 50,000 monofilament monofilaments is preferable for handling. Usually, the roving of these continuous reinforcing fibers can be used after being surface-treated with a silane coupling agent or the like in order to improve the interfacial adhesion with the resin.

The extruder used in the present invention is provided with a control mechanism section having a modified surface of the screw and / or cylinder on the downstream side of the continuous reinforcing fiber supply port, and further, a cylinder between the tip of the screw and the die. The structure in which a rectifying plate is provided is the basic structure. The screw may be single-screw or multi-screw, but a multi-screw extruder such as a twin-screw extruder having a unit structure is preferable.

The type of the twin-screw extruder may be of the same direction, different directions, meshing type, non-meshing type or the like. The screw may have a deep groove or a shallow groove, and the number of threads may be 1, 2, 3 or the like. Compared to a single-screw extruder, a twin-screw extruder can control the resin supply amount and the screw rotation speed independently, and thus the addition amount of the reinforcing fiber can be easily controlled. Further, the unit structure has an advantage that the above-mentioned control mechanism portion can be easily provided and the position thereof can be easily changed. In addition, the extruder is equipped with a degassing port after the control mechanism to prevent deterioration of physical properties and poor appearance due to volatile components generated from the surface treatment agent for the resin and reinforcing fibers and bubbles entrapped by the reinforcing fibers. Is desirable.

FIG. 1 shows a twin-thread screw type twin-screw extruder showing an example of the extruder used in the present invention.

In this extruder, two screws 1 are inserted into a cylinder 2, a resin supply port 3 is provided at one end of the cylinder 2, and a discharge die 5 is provided at the other end. It is provided. Further, a reinforcing fiber supply port 4 is provided in the middle part. Further, inside the cylinder 2, a control mechanism portion 6 which is a feature of the present invention is provided on the downstream side of the reinforcing fiber supply port 4, and further, the tip portion of the screw 1 and the die 5 are provided.
A rectifying plate 7 is provided between the and.

In such a twin-screw extruder, the thermoplastic resin supplied from the resin supply port 3 is melted while being conveyed by the screw 1 and completely melted in the kneading zone 8. On the other hand, continuous reinforcing fibers that account for 45 to 80% by weight of the molten resin are supplied into the molten resin from the reinforcing fiber supply port 4, and are sent to the control mechanism section 6 together with the molten resin.

The reinforcing fibers and the molten resin are uniformly kneaded in the control mechanism section 6 to form a molten resin flow containing the reinforcing fibers, and the molten resin flow is conditioned by the straightening plate 7 and then the die 5 is formed. Is discharged as a gut G from. The gut G is cooled and then cut into fiber-reinforced thermoplastic resin pellets. In the pellet manufacturing process, the continuous reinforcing fiber supplied from the reinforcing fiber supply port 4 is wound into the cylinder at a constant speed by the shear force between the screw flight and the cylinder, and advances while winding around the screw. Usually, in the case of chopped strands, it advances in the groove of the screw together with the molten resin, but the continuous reinforcing fiber supplied in the above step goes over the screw flight and advances. Moreover, since the extruder is provided with the control mechanism portion 6 in which the outer peripheral portion of the screw and the inner wall of the cylinder are modified, the continuous reinforcing fiber and the molten resin wound around the screw are controlled by the control mechanism portion 6. Can be mixed uniformly.

The extruder of the present invention preferably has two independent resin supply ports for the thermoplastic resin and the reinforcing fiber supply ports for the continuous reinforcing fibers. The continuous reinforcing fiber supply port is provided downstream of the molten portion of the thermoplastic resin so that the continuous reinforcing fiber is introduced into the molten resin. When the reinforcing fiber and the thermoplastic resin are added at the same time, thermal deterioration of the resin is likely to occur and it becomes difficult to obtain good mechanical properties. Further, the supply port of the continuous reinforcing fiber may be sealed with nitrogen or the like so that the contact between the molten resin and the air is cut off. Such a seal can prevent the oxidative deterioration of the resin.

It is preferable that the control mechanism portion having the surface of the screw and / or the cylinder deformed is provided adjacent to the reinforcing fiber supply port. If the control mechanism is too far from the supply port, before the reinforcing fibers reach the control mechanism,
In some cases, the fiber bundles are worn between the normal screw flight and the cylinder to leave bundle fibers, and the reinforcing fibers may not be uniformly dispersed.

If an ordinary kneading section is provided after the reinforcing fiber supply port, the fiber bundle may remain and the reinforcing fibers may not be uniformly dispersed. In addition, the mechanical properties of the resin deteriorate due to the heat deterioration of the resin due to the heat generated by shearing. Further, also when a kneading section is provided after the control mechanism section, mechanical properties are similarly deteriorated due to heat deterioration of the resin, which is not preferable.

As a specific example of the modification processing of the control mechanism portion, it is possible to carry out concavo-convex processing on the screw surface, preferably a cylindrical screw surface or an elliptical screw surface such as a neutral element. The method for forming the unevenness is not particularly limited, but cutting, grinding, blasting, or the like can be adopted.

FIGS. 2 (a) and 2 (b) show an example of the control mechanism portion 6, in which the surface of the screw 1 having an elliptical cross section and the surface of the cylinder 2 having a cylindrical shape are erected in a saw blade shape in the direction perpendicular to the screw axis. The blade-shaped processing part 10 to be provided is provided. Of course, the blade-shaped processing portion 10 may be provided on either the screw 1 or the cylinder 2.

As shown in FIG. 2 (c), the blade-shaped working portion 10 has a specific cutting edge angle θ, and the height h between the peak and the valley bottom.
And the distance (pitch) t between adjacent peaks. The edge angle θ is preferably 60 degrees or less,
In particular, it is preferably set to 45 degrees or less. The height h between the peak and the bottom of the valley is preferably 30 times or more, more preferably 75 times or more the fiber diameter of the reinforcing fiber. Also, the pitch t between the peaks
Is preferably 30 to 200 times the fiber diameter of the reinforcing fiber.

FIGS. 3A and 3B show another example of the control mechanism section 6. In this control mechanism portion 6, the mesh processing portion 11 is formed on each of the screw 1 and the cylindrical cylinder 2 which have the same elliptical cross section. Of course,
It may be provided on either the screw 1 or the cylinder 2.

The control mechanism portion 6 of FIG. 4A is an example of a forward full flight screw in which the saw blade-shaped blade-shaped processing portion 10 is provided on the flight of the screw. The control mechanism unit 6 of FIG. 4B is an example of a forward full flight screw in which the mesh processing unit 11 is provided on the flight of the screw 1 as well.

In the above-mentioned control mechanism section, the pitch, depth, etc. of the profiled irregularities can be appropriately changed according to the amount of reinforcing fibers added. The modified screw and cylinder can be used alone or in combination.

In the examples of FIGS. 2 and 3, the screw cross section has an elliptical shape, but it may of course have a circular shape. In the case of an intermeshing type twin-screw extruder, it is preferable that the twin-screw extruder has an elliptical shape, whereby the self-cleaning property can be enhanced. Moreover, you may make it combine the screw and / or the cylinder from which different shape processing is carried out. Further, the length of the control mechanism portion may be changed, the diameter may be changed at both end portions as necessary, or irregularities having different pitches or depths may be combined.

The deforming process is not limited to the above-mentioned example, and the reinforcing fibers and the molten thermoplastic resin are uniformly kneaded, and a "comb" for preventing heat deterioration of the resin is formed. Any other mechanism may be used as long as it has such a mechanism.

The length of the control mechanism portion is such that the reinforcing fiber and the thermoplastic resin can be sufficiently kneaded, the gut take-off property, the dispersibility of the reinforcing fiber, and the thermal deterioration of the resin due to heat generation due to shearing. The diameter of the screw is preferably 0.1 to 10 times, more preferably 0.2 to 5 times.

FIGS. 5 (a) and 5 (b) illustrate the flow regulating plate 7 mounted in the cylinder 2 between the tip of the screw 1 and the die 5 in the present invention.

Since the rectifying plate 7 is provided to regulate the flow of the molten resin containing the continuous reinforcing fibers, the structure is not particularly limited as long as it has a rectifying function. However, preferably, FIG.
As shown in (b), it is preferable that at least the raw material supply side of the extruder is formed in a wedge shape. By forming the wedge shape in this way, it is possible to prevent the continuous reinforcing fibers from being deposited on the flow regulating plate 7. The wedge angle that prevents the continuous reinforcing fibers from accumulating on the straightening plate is preferably 90 degrees or less, and more preferably 60 degrees or less.

The shape of the flow regulating plate 7 may be curved in order to more effectively correct the spiral flow. The curved shape for that purpose is not particularly limited, but the whole straightening plate is curved into an arc shape or a part of an ellipse or a parabola, or only the extruder side of the straightening plate is an arc shape or a part of an ellipse or a parabola. The curved shape may be a curved shape, or the discharge side of the rectifying plate may be curved in an arc shape, a part of an ellipse, or a parabola shape.

There are no particular restrictions on the mounting position of the rectifying plate, the number of mounting plates, the mounting direction, etc., and only one plate may be mounted, or it may be mounted in multiple stages or in a grid pattern.

In the fiber-reinforced thermoplastic resin pellet aggregate obtained by the present invention described above, the individual pellets have a high content rate of 45 to 80% by weight of the average fiber content Wa, and the fiber content of each pellet is high. The average fiber content W
Within a range of ± 0.03 × Wa with respect to a, the variation is extremely small. Moreover, the ratio Lw / Ln of the weight average fiber length Lw and the number average fiber length Ln of the reinforcing fibers in each pellet is 1.1 or more.

The fiber-reinforced resin pellet aggregate of the present invention is A
The flexural modulus measured according to the standard of STM D-790 is 20 GPa or more, and in many cases, the notched Izod impact strength measured according to the standard of ASTM D-258 is 170 J / Higher quality can be obtained with m or more.

When the fiber-reinforced resin pellet aggregate of the present invention is subjected to molding, the pellet aggregate of the present invention may be used alone, or it may be used as a master pellet to add a non-reinforced resin or other additives. It is also possible to mix with the contained pellets to obtain a molded product having an arbitrary fiber content.

The molding method is not particularly limited as long as it can be molded using the pellet aggregate, and various molding methods such as blow molding, injection molding and extrusion molding can be performed. When using a pellet containing a pellet aggregate or a fiber bundle in which the reinforcing fibers are not uniformly dispersed like the pellet of the present invention, the fiber bundle remaining in the molded article causes stress concentration, and the elastic modulus and impact strength Such excellent mechanical properties cannot be obtained.

Molded articles to which the fiber-reinforced heat or composition resin pellet aggregate of the present invention can be applied include the following ones, which can be variously applied.

That is, various gears, sensors, connectors, sockets, resistors, switches, coil bobbins, capacitors, plugs, printed circuit boards, tuners, speakers, microphones, headphones, motors, magnetic head bases, FDD carriages, FDD chassis, motor brushes. Electric / electronic parts typified by holders; TVs, parabolic antennas, VTRs, irons, hair dryers, rice cookers, microwave ovens, audio equipment such as audio / laser disks / compact disks,
Lighting equipment, refrigerators, air conditioners, washing machines, dryers, typewriters, word processors, computers, telephones, facsimiles, copiers and other household electrical appliances and covers; cleaning equipment, various motors, helmets Parts and covers related to machines and tools represented by, such as golf club heads and shafts, kendo trunks, goal and tennis rackets such as rugby and soccer, hulls and oars, and sports represented by skis and marine equipment.・ Leisure-related parts and covers; microscopes,
Optical equipment and precision machinery related parts such as binoculars, cameras, clocks and bars; furniture such as desks and chairs, stationery,
Miscellaneous goods such as stationery and toys; building materials typified by window frames, columns, roofing materials, walls; intake manifolds, air intake nozzle snorkels, fuel pumps, fuel-related exhaust / intake systems pipes, cylinder head covers, Bumper beam, seat frame, bumper, instrument panel, wheel cap, wheel cover, tire wheel, battery tray, fuel tank,
Engine cooling water joint, carburetor main body, radiator, door mirror base, crankcase, shift lever, transmission cover, spoiler, frame and outer plate, drive shaft, thermostat base for air conditioner, heating hot air flow control valve, brush holder for radiator motor. , Water pump impeller, Turbine vane, Wiper motor related parts, Distributor, Starter switch, Starter relay, Transmission system wire harness, Window washer nozzle, Air conditioner panel switch board, Fuse connector, Horn terminal, Electrical component insulating plate, Step motor Rotor, lamp socket, lamp reflector, lamp housing, brake Stone, solenoid bobbin, engine oil filter, such as ignition device cases, automobile and vehicle-related parts and covers,; a, and other various applications.

[0055]

EXAMPLES The present invention will be described below in comparison with examples and comparative examples.

In these examples and comparative examples, the composition ratio of the reinforcing fiber and the thermoplastic resin was calculated from the weight change of pellets burned only in the thermoplastic resin in an electric furnace at 450 ° C. The fiber length of the reinforcing fiber is about 1000 (± 200
This was obtained by measuring the fiber length of the (book). The flexural modulus was measured based on the regulations of ASTM D-790 after injection molding a pellet aggregate. Notched Izod impact strength is
The pellet aggregate was injection-molded and measured according to the standard of ASTM D-256. The molding lower limit pressure was determined as the molding lower limit pressure which is the lowest injection pressure at which the resin is completely filled when the injection speed is maximized. This molding lower limit pressure is a measure of the fluidity of the molten resin, and it can be said that the lower the pressure, the better the fluidity and the moldability.

Example 1 In producing the fiber-reinforced resin pellet aggregate described below, as an extruder, as shown in FIG. 1, it has two supply ports in the extrusion direction, the screw diameter is 30 mm, and L / D = 35. Directional twin-screw extruder (TEX30, Japan Steel Works, Ltd.)
It was used.

The two screws of this extruder are double-threaded screws with a mutual engagement of 3.5 mm, and kneading is performed in the order of L / D = 2 in the reverse order immediately before the second supply port. 2 (a) (pitch 1 mm, on the discharge side of the second supply port via a full flight screw of L / D = 1).
A neutral screw-shaped control mechanism with an elliptical cross section of L / D = 0.5 that has been processed such as a blade edge angle of 30 degrees and a peak height and a valley bottom height of 1.5 mm) is provided. A screw shape was used.

Further, the straightening plate shown in FIGS. 5 (a) and 5 (b) was attached in the cylinder between the tip of the screw and the die.

To this extruder, nylon 66 resin pellets (CM3001 manufactured by Toray Industries, Inc.) were fed at a constant rate of 12.3 kg / h from a screw type pellet feeder at a cylinder temperature of 290 ° C. First, extrusion was performed only with the resin at a screw rotation speed of 200 rpm.
Next, after confirming that the resin was completely melted at the second supply port, 17 glass rovings (manufactured by Nippon Electric Glass Co., Ltd.) having a diameter of 13 μm and a count of 1400 tex were introduced from the second supply port. did.

The glass roving was constantly drawn into the extruder by the screw rotation, sent to the tip of the extruder together with the molten resin, and extruded in a gut shape. The extruded gut was cooled in a cooling layer, cut into 4 mm length, and pelletized. In this extrusion molding, there were no particular problems with gut take-off stability or resin deterioration (discoloration).

The obtained pellets were vacuum dried at 80 ° C. for 8 hours, and then injection-molded with an IS55EPN injection molding machine manufactured by Toshiba Machine Co., Ltd. under the conditions of a cylinder temperature of 300 ° C. and a mold temperature of 80 ° C., and a maximum injection speed ( (Set value 266 mm / sec)
The lower molding limit pressure and the physical properties of the molded product at that time were measured. Further, the average fiber content in the pellet, the weight average fiber length Lw and the number average fiber length Ln were measured, and the ratio Lw / Ln was calculated. Table 1 shows the results.

Example 2 Extrusion was carried out under the same conditions as in Example 1 except that the amount of resin supplied was 9.1 kg / h and the number of glass rovings supplied was 20, to produce pellets. There were no particular problems such as the stability of the gut collection and the deterioration (discoloration) of the resin. The obtained pellets were evaluated in the same manner and the results shown in Table 1 were obtained.

Comparative Example 1 The same conditions as in Example 1 except that glass fibers having a diameter of 13 μm were used as chopped strands having a length of 3 mm (manufactured by Nippon Electric Glass Co., Ltd.) and the glass fiber supply rate was 18.8 kg / h. Was extruded to produce pellets. There was no problem with the deterioration (discoloration) of the resin, but there was fluff on the gut and the gut was broken. The obtained pellets were evaluated in the same manner and the results shown in Table 1 were obtained.

Comparative Example 2 Pellets were produced by extruding under the same conditions as in Comparative Example 1 except that the resin supply rate was 9.31 kg / h and the glass fiber supply rate was 21.71 kg / h. There was no problem with the deterioration (discoloration) of the resin, but the gut had fluff, and the gut was frequently broken. The obtained pellets were evaluated in the same manner and the results shown in Table 1 were obtained.

COMPARATIVE EXAMPLE 3 Instead of the control mechanism of the extruder used in Example 1, five kneading disks inclined at 45 degrees with L / D = 1 were provided in a portion corresponding to the control mechanism. Extruders were produced under the same conditions as in Example 1 except that a screw having the screw elements provided in the reverse order was used, and pellets were produced under the same conditions as in Example 1. There was no problem with the gut take-back stability, but the resin was discolored. The obtained pellets were evaluated in the same manner and the results shown in Table 1 were obtained.

[0067]

[Table 1]

As shown in Table 1, the pellets according to the invention obtained in Examples 1 and 2 have a high fiber content,
It can be seen that, compared with the pellets obtained in Comparative Examples 1 to 3, the variation in the fiber content is small, and the flexural modulus of the molded product and the notched Izod impact strength are also excellent in physical properties. Further, it can be seen that the lower limit of molding pressure, which is an index of moldability, is low, and the moldability is excellent. On the other hand, the pellets of Comparative Examples 1 and 2 have large variations in fiber content, low bending elastic modulus, high molding lower limit pressure, and poor moldability. Further, the pellets of Comparative Example 3 have a small variation in the fiber content, but the physical properties are low due to the deterioration of the resin.

[0069]

As described above, according to the present invention, the control mechanism section in which at least one of the cylinder and the screw is surface-deformed is provided on the downstream side of the reinforcing fiber supply port,
And using an extruder with a straightening plate disposed between the screw tip and the die, by producing a fiber-reinforced thermoplastic resin pellet aggregate by kneading the thermoplastic resin and continuous reinforcing fibers, high fiber content However, the dispersion of the fiber content is extremely small, the reinforcing fibers are uniformly dispersed, and a fiber-reinforced thermoplastic resin pellet aggregate having excellent rigidity (elastic modulus) can be obtained.

In addition, by using this fiber-reinforced thermoplastic resin pellet aggregate, a molded product having improved rigidity and impact strength can be obtained in many cases.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an extruder used for producing a fiber-reinforced thermoplastic resin pellet aggregate of the present invention.

2A is a perspective view of a main part of a screw part of a control mechanism provided in the extruder of FIG. 1, and FIG. 2B is a perspective view of a main part of a cylinder part of the control mechanism, FIG. 3C is a vertical cross-sectional view of a blade-shaped processing portion of the control mechanism portion.

3 (a) is a perspective view of a main part of a screw portion which is another example of the control mechanism portion provided in the extruder of FIG. 1, and (b) is a cylinder portion which is another example of the control mechanism portion. FIG. 4 is a perspective view of a half-divided main part of FIG.

4 (a) and 4 (b) are perspective views of a main part of a screw portion which is still another example of the control mechanism portion provided in the extruder of FIG.

5 (a) is a schematic horizontal sectional view of a tip portion of the extruder in FIG. 1, and FIG. 5 (b) is a schematic vertical sectional view thereof.

[Explanation of symbols]

 1 Screw 2 Cylinder 3 Resin Supply Port 4 Reinforcing Fiber Supply Port 5 Die 6 Control Mechanism Section 10 Blade-shaped Processing Section (Deformed Processing) 11 Reticulated Processing Section (Deformed Processing)

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Claims (9)

[Claims] 1. An aggregate of fiber-reinforced thermoplastic resin pellets, wherein an arbitrarily collected pellet aggregate 10 g has an average fiber content Wa of 45 to 80% by weight, and the fiber content of each pellet is The average fiber content Wa is within a range of ± 0.03 × Wa, and the ratio Lw / Ln of the weight average fiber length Lw and the number average fiber length Ln of the reinforcing fibers in each pellet is 1.1 or more. Therefore, ASTM D-79
Flexural modulus is 20G when measured based on the rule of 0
A fiber-reinforced thermoplastic resin pellet aggregate having a Pa or more. 2. An aggregate of fiber-reinforced thermoplastic resin pellets, wherein 10 g of arbitrarily collected pellet aggregate has an average fiber content Wa of 45 to 80% by weight, and the fiber content of each pellet is Pellets within the range of ± 0.03 × Wa with respect to the average fiber content Wa are 90% by weight or more of the pellet aggregate 10 g, and the weight average fiber length Lw of the reinforcing fibers in each pellet. And the number average fiber length Ln ratio Lw / Ln is 1.1 or more,
A fiber-reinforced thermoplastic resin pellet aggregate having a flexural modulus of 20 GPa or more when measured based on the regulations of D-790. 3. The fiber-reinforced thermoplastic resin pellet aggregate according to claim 1, which has an average fiber content Wa of 60 to 80% by weight. 4. The reinforcing fiber is glass fiber.
5. A fiber-reinforced thermoplastic resin pellet aggregate according to any one of 1. 5. A notched Izod impact strength of 170 J when measured in accordance with ASTM D-256.
/ M or more, the fiber-reinforced thermoplastic resin pellet aggregate according to any one of claims 1 to 4. 6. An extruder having a cylinder and a screw, wherein at least a part of the cylinder and / or the screw is provided with a control mechanism part having a surface-deformed shape,
Using an extruder having a straightening plate arranged between the screw tip and the die, the thermoplastic resin is melted, and continuous reinforcing fibers occupying 45 to 80% by weight in the molten resin are supplied to the control mechanism section. The fiber-reinforced thermoplastic resin pellet aggregate according to claim 1, wherein the fiber-reinforced thermoplastic resin pellet aggregate is manufactured by kneading, extruding through the straightening plate and pelletizing. Manufacturing method. 7. The extruder is a multi-screw type, and a resin supply port and a fiber supply port are separately provided in the extruder, and the reinforcing fiber supply port is arranged on the downstream side of the resin supply port. 7. The method for producing a fiber-reinforced thermoplastic resin pellet aggregate according to item 6. 8. The uneven processing is uneven processing.
Alternatively, the method for producing a fiber-reinforced thermoplastic resin pellet aggregate according to item 7. 9. A fiber-reinforced thermoplastic resin molded product obtained by molding the pellet aggregate according to any one of claims 1 to 5.