JPH10237283A - Fiber reinforced thermoplastic resin composition - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a fiber-reinforced thermoplastic resin composition having excellent moldability, mechanical properties, and hydrolyzability, and a method for producing the same with high productivity. . SOLUTION: Polybutylene terephthalate, reinforcing fiber,
In a fiber-reinforced thermoplastic resin composition comprising an epoxy compound, the weight-average fiber length (Lw) of the reinforcing fibers in the composition
(Lw / d) between 50 and 250 and the ratio of the weight average fiber length (Lw) to the number average fiber length (Ln)
(Lw / Ln) is 1.1-3.5, The fiber reinforced thermoplastic resin composition characterized by the above-mentioned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced thermoplastic resin composition in which reinforcing fibers are opened to control the fiber length, and has excellent moldability and mechanical properties, and a method for producing the same with high productivity. Further, the present invention relates to a fiber-reinforced thermoplastic resin composition having excellent thermal properties, particularly excellent hydrolyzability.

[0002]

BACKGROUND OF THE INVENTION Fiber-reinforced thermoplastic resins are used in various applications such as automobile parts and OA equipment, taking advantage of their excellent mechanical properties.
There is a method in which chopped strands are kneaded using an extruder as disclosed in JP-A-20738. However, in this method, the reinforcing fibers are broken and do not exhibit good mechanical properties. Therefore, studies have been made to improve the mechanical properties and the like by increasing the fiber length of the reinforcing fibers.
No. 94 Pultrusion method (pultruding method)
The fiber extruder is a fiber-reinforced thermoplastic resin composition in which a continuous roving of reinforcing fibers is coated with a thermoplastic resin and cut to a predetermined length, or a glass fiber is spirally extruded in the form of a string as disclosed in JP-B-44-16793. It is known to cut into a suitable length by placing it in a melt therein. However, in these compositions, although the reinforcing fibers become long, the degree of opening and the kneading action are insufficient, so that not only the fluidity and mechanical properties are insufficient, but also the productivity is low. Further, for the purpose of improving strength and thermal properties, particularly hydrolyzability, Japanese Patent Publication No. 55-41700 and Japanese Patent Application Laid-Open No. 6-212065.
It has been proposed to use an epoxy compound together with a reinforcing material as described in the publication. However, even with such a method, it is difficult to obtain a significant improvement effect.

Therefore, the present invention solves the above-mentioned problems of the prior art, and has excellent mechanical properties and hydrolyzability.
An object is to obtain a fiber-reinforced thermoplastic resin composition having excellent moldability.

[0004]

That is, the present invention provides:
(1) In a fiber-reinforced thermoplastic resin composition obtained by blending (A) polybutylene terephthalate, (B) reinforced fiber, and (C) an epoxy compound, the weight-average fiber length of (B) reinforced fiber in the composition The relationship (Lw / d) between (Lw) and the fiber diameter (d) is 50 to 250, and the ratio (Lw / L) of the number average fiber length (Ln) to the weight average fiber length (Lw)
n) is a fiber-reinforced thermoplastic resin composition of 1.1 to 3.5, and the blending amount of the components (2) (A) and (B) is (A) and (B) with respect to the total of (A) and (B). ) 40-99% by weight of polybutylene terephthalate, (B) 1-60% by weight of reinforcing fiber
Wherein (C) the epoxy compound is 2.5 parts by weight or less based on 100 parts by weight of the total of (A) and (B), (3)
(A) The fiber-reinforced thermoplastic resin composition according to the above (1) or (2), wherein the polybutylene terephthalate is a polybutylene terephthalate having a COOH terminal group of 10 to 60 eq / t and an intrinsic viscosity of 0.60 to 1.25. (4)
(A) The fiber-reinforced thermoplastic resin according to any one of the above (1) to (3), wherein the polybutylene terephthalate is a polybutylene terephthalate having a COOH terminal group of 20 to 55 eq / t and an intrinsic viscosity of 0.65 to 1.10. A composition, and
(5) The fiber reinforcement according to any one of the above (1) to (4), wherein (C) the epoxy compound is at least one selected from a compound having a glycidyl ester, a compound having a glycidyl ether, and a glycidyl ester and a glycidyl ether. It is a thermoplastic resin composition.

The present invention also provides (6) the above (1) to (5)
An extruder provided with a fiber-reinforced thermoplastic resin composition according to any one of the above, and (7) a fiber opening / fiber length control mechanism section in which at least a part of a screw and / or a cylinder is surface deformed. Is used to melt the polybutylene terephthalate of the component (A) and the epoxy compound of the component (C), and to supply the reinforcing fiber of the component (B) in a continuous state into the polybutylene terephthalate in the molten state, The fiber reinforced thermoplastic resin composition according to any one of the above (1) to (5) is produced by opening the reinforcing fiber while passing through the opening / fiber length control mechanism, and controlling the fiber length. A method for producing a fiber-reinforced thermoplastic resin composition, characterized in that:

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The polybutylene terephthalate (A) used in the present invention may be an ordinary polymerization method such as a polycondensation reaction using terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative as main components. And may contain a copolymer component in an amount of less than about 20 wt% as long as the properties are not impaired. Preferred examples of these (co) polymers include:
Polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate /
Sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene (terephthalate / naphthalate), poly (butylene / ethylene) terephthalate, and the like, which may be used alone or as a mixture of two or more.

Further, in these polymers and copolymers, the amount of COOH terminal groups determined by potentiometric titration of the m-cresol solution with an alkaline solution is 10 to 60 eq / t.
(Terminal group amount per ton of polymer) is preferable, and 20 to 55 eq / t is more preferable.
The intrinsic viscosity measured at 25 ° C. using an o-chlorophenol solution is preferably in the range of 0.60 to 1.25, more preferably 0.65 to 1.10. 65-0.95 is preferred. When such optimum conditions are satisfied, a fiber-reinforced thermoplastic resin composition having particularly excellent fluidity and mechanical properties during molding can be obtained.

[0008] The reinforcing fiber (B) in the composition of the present invention is not particularly limited as long as it is generally used for reinforcing a resin, and may be glass fiber, carbon fiber, metal fiber and organic fiber ( Nylon, polyester, aramid, polyphenylene sulfide, liquid crystal polymer, acryl, etc.) can be used, and one or two or more of them can be used in combination, but glass fiber and carbon fiber are most desirable. The fiber diameter is not particularly limited as long as it is generally used for reinforcing a resin, and preferably has a diameter of 4 to 25 μm, particularly 6 to 20 μm.
Fibers can be used. Relationship between weight average fiber length (Lw) and fiber diameter (d) of reinforcing fibers in the composition (Lw /
d) is 50 to 250, more preferably 53 to 200, and the ratio (Lw / Ln) of the number average fiber length (Ln) to the weight average fiber length (Lw) is 1.1 to 3.5, more preferably It is preferably 1.1 to 2.0. Lw
When / d is small, sufficient effect of improving mechanical properties cannot be obtained, and when / d is large, reinforcing fibers are entangled and become non-uniform or flowability is deteriorated, which is not preferable. Also, L
When w / Ln is less than 1.1, it means a composition obtained by a pultrusion method or the like in which the fiber length is substantially constant,
In this case, the openability of the reinforcing fiber is inferior and good moldability (fluidity) cannot be obtained. If the size is large, the flow becomes uneven due to the entanglement of the fibers, and a uniform molded product cannot be obtained. In the present invention, the weight-average fiber length and the number-average fiber length are obtained by taking a photograph of a part of a molded product obtained by burning only a thermoplastic resin in an electric furnace at 500 ° C. with a microscope, and obtaining 500 or more fibers from the photograph. Measure the length of
It can be determined from the fiber length distribution.

The weight-average fiber length (Lw) and the number-average fiber length (Ln) are defined as follows.

[0010]

## EQU1 ## Weight average fiber length (Lw) = Σ (ρπr ² Li × Li) / Σ (ρπr ² Li) = ΣLi ² / ΣLi Number average fiber length (Ln) = ΣLi / n where ρ: reinforced fiber Density r: radius of reinforcing fiber Li: length of i-th reinforcing fiber n: number of reinforcing fibers

Further, in the present invention, the reinforcing fibers are preferably opened in the composition, and the openability refers to a state in which the reinforcing fibers in the composition are substantially opened to single fibers. Specifically, among the observed reinforcing fibers, the number of reinforcing fibers bundled in 10 or more bundles is 40% of the total number of reinforcing fibers.
%.

The mixing ratio of (A) polybutylene terephthalate and (B) reinforcing fiber is determined based on the total of (A) and (B) from the viewpoint of mechanical properties, moldability and surface smoothness.
(B) The reinforcing fiber content is preferably 1 to 60% by weight, particularly preferably 3 to 55% by weight.

As the epoxy compound (C) used in the present invention, a compound having an epoxy group having an epoxy equivalent of 1000 or less, which is the number of grams of a compound containing an epoxy group of 1 gram equivalent, has an improved hydrolysis resistance. It is preferably mentioned from the viewpoint of the effect, and may be generally used by being added to a thermoplastic resin.

Further preferred are compounds having a glycidyl ester in the molecule, compounds having a glycidyl ether, and compounds having both glycidyl ester and glycidyl ether. These epoxy compounds are 1
It is used in a kind or two or more kinds, and in particular, a combination of a compound having a glycidyl ester and a compound having a glycidyl ether or a compounding of a compound having both a glycidyl ester and a glycidyl ether is preferable. Specific epoxy compounds include resorcin diglycidyl ether, sorbitol polyglycidyl ether, diethylene glycol diglycidyl ether, dibromophenyl glycidyl ether, dibromo neopentyl glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol di Glycidyl ether, polyglycerin polyglycidyl ether, acrylic glycidyl ether, sorbitan polyglycidyl ether, pt-butylphenylglycidyl ether, phenylglycidyl ether, bisphenol-A-diglycidyl ether, bisphenol-S-diglycidyl ether, hydroquinone diglycidyl Ether, diglycidyl dimer acid, diglycidyl o-phthalate Ether, hexahydrophthalic acid diglycidyl ester,
Examples include glycidyl neodecanoate, diglycidyl terephthalate, glycidyl soybean oil, monoglycidyl benzoate, monoglycidyl stearate, monoglycidyl laurate, and glycidyl p-hydroxybenzoic acid ether.

The amount of the epoxy compound (C) used in the present invention is determined from the viewpoint of hydrolyzability and moldability (flowability).
It is preferably at most 2.5 parts by weight, particularly preferably at most 1.5 parts by weight, based on 100 parts by weight of the total of (A) polybutylene terephthalate and (B) reinforcing fiber. The lower limit is not particularly limited except that it is an essential component, but is preferably at least 0.03 parts by weight, particularly preferably at least 0.05 part by weight.

The method for producing the fiber-reinforced thermoplastic resin composition of the present invention is not particularly limited as long as a composition satisfying the above requirements can be obtained.
This is a method for producing a fiber-reinforced thermoplastic resin composition by melt-kneading a reinforcing fiber continuous with a thermoplastic resin in an extruder cylinder. More specifically, the molten thermoplastic resin and the continuous reinforcing fibers are passed through a control mechanism formed by a screw and / or cylinder whose surface is modified to have at least a part of the screw surface and / or cylinder inner wall. In this method, the reinforcing fibers are opened by the comb action of the deformed surface to control the fiber length.

An extruder in which a continuous reinforcing fiber is opened and a screw and / or a cylinder for controlling the fiber length is processed is a single-screw or multi-screw extruder, in which an extruder is provided. It refers to an extruder that includes a mechanism for controlling the degree of opening of continuous reinforcing fibers and the fiber length. The continuous reinforcing fiber is wound at a constant speed into the extruder cylinder by the shearing force between the screw flight and the cylinder, and advances while winding around the screw. Normally, the resin flows in the groove of the screw, but in the above-described method, the continuous reinforcing fiber advances over the screw flight. Therefore, by performing various processes on the outer peripheral portion of the screw and the inner wall of the cylinder, a "comb" effect can be exerted between the screw and the cylinder on the reinforcing fibers wound around the screw. As an example of a specific control mechanism, a screw surface, preferably an elliptical screw surface such as a cylindrical screw surface or a neutral element, is subjected to deforming processing. Is performed. The method for forming the irregularities is not particularly limited, but cutting, grinding, blasting, or the like can be employed. Examples of the shape of the unevenness include a blade-like processing and a mesh-like processing, and are not particularly limited as long as continuous reinforcing fibers can be opened and the fiber length can be controlled. FIGS. 1A and 1B show an example in which the surface of the screw 1 and the inner wall of the cylinder 3 are subjected to edge-like irregularities 2 and 4. These are the blade-shaped processing portions 2 and 4 in which irregularities are formed at a specific blade angle in a direction perpendicular to the screw axis, and the blade-shaped processing portions 2 and 4 have a specific blade angle (θ), as shown in FIG. It can be expressed by the height (h) of the peaks and valleys of the uneven shape and the distance and pitch (t) between the peaks and the adjacent peaks. The specific edge angle (θ) is desirably 60 degrees or less, and particularly desirably 45 degrees or less. The height (h) of the peaks and valleys of the uneven shape is 30 fiber diameters.
It is preferably at least 70 times, more preferably at least 70 times. If the cutting edge angle is too large or trapezoidal, or if the ratio of the height of the peaks and valleys to the fiber diameter is too small, the effect of the "comb" on the reinforcing fibers will be small and the fiber will be opened. There is a tendency for the fiber length to be shortened due to poor properties or rubbing action. The pitch (t), which is the distance between the cutting edge and the cutting edge adjacent thereto, is 30 times the reinforcing fiber diameter.
It is preferable to make it up to 200 times.

The control mechanism is desirably provided adjacent to the continuous reinforcing fiber feeding section. If it is too far from the input section, the reinforcing fibers will be worn between the normal screw flight and the cylinder before reaching the control mechanism,
It is not desirable because it becomes difficult to control the fiber length and the degree of fiber opening. Further, if a normal kneading section or a backflow section is provided after the charging section, the reinforcing fibers are broken there, which is not desirable. If a kneading section is provided between the charging section and the control mechanism section, the reinforcing fibers are cut as in the case described above, and the control becomes impossible. Furthermore, it is not desirable to provide a kneading section after the control mechanism section, since the fibers are damaged unless the fiber length is particularly shortened.

The continuous reinforcing fiber charging section is provided downstream of the thermoplastic resin melting section, and is charged into the molten resin. If the resin is introduced at the same time as the resin, the fiber tends to be cut when the resin is melted, and the resin tends to be uncontrollable. Further, it is desirable to seal the continuous reinforcing fiber input portion with nitrogen or the like and cut off the contact between the molten resin and the air in order to prevent the resin from being oxidized and deteriorated.

The extruder is not particularly limited, but a multi-screw extruder such as a unit-structured twin-screw extruder is particularly convenient. As the multi-screw extruder, the most general twin-screw extruder is preferable, and any type of co-direction, different direction, meshing type, non-meshing type may be used, but the same direction is most preferable. Also, as a screw, a deep groove, a shallow groove, one line,
Articles, three-section screws, etc. can be used. Compared with the single screw extruder, the twin screw extruder can control the resin supply amount and the screw rotation speed independently, so that it is easier to control the addition amount of the reinforcing fiber. Further, the unit structure is advantageous in that a control mechanism for controlling the degree of opening and the fiber length can be easily provided, and the position thereof can be easily changed.

For the purpose of preventing deterioration in physical properties and poor appearance due to volatile components generated from resin and fibers and bubbles embraced by reinforcing fibers, a deaeration port is provided after the control mechanism for controlling the degree of opening and the fiber length. Is desirably provided.

In the present invention, it is important to provide a control mechanism having irregularities on at least a part of the surface of a screw such as a cylinder or an elliptic cylinder after fiber supply and / or the inner wall of the cylinder. Pitch and depth can be changed depending on the desired degree of control. In addition, a screw having processing and a cylinder having processing can be used independently,
They can be used in combination. Although the screw cross section is exemplified by an elliptical shape, a circular shape is also possible. In particular, in the case of a mesh type twin screw extruder, an elliptical shape is desirable in order to maintain self-cleaning properties. Furthermore, in order to control the fiber length, it is also possible to change the length of the control mechanism, change the diameter at both ends if necessary, or use a combination of projections having different pitches and depths. The preferred length of the control mechanism is 0.1 to 10 times, more preferably 0.2 to 5 times, particularly preferably 0.3 to 3 times the screw diameter. The present invention is not limited to these examples,
The reinforcing fibers are opened to single fibers, and include all processes having a function such as "comb" according to the target fiber length.

The number of continuous reinforcing fibers to be bundled is not particularly limited, but a bundle of 10 to 20,000 single fibers or monofilaments is desirable.
Usually, these reinforcing fibers are preferably used after being subjected to a surface treatment with a sizing agent or a coupling agent for improving interfacial adhesion to a resin and handling characteristics. For example, a known surface treatment such as Japanese Patent Publication No. 4-47697 can be performed. These surface treatments may use previously treated reinforcing fibers, or may be performed immediately before the reinforcing fibers are introduced into the extruder to continuously produce the structure of the present invention.

The composition of the present invention can be formed into pellets by a usual known method and then subjected to molding.

The pellets made of the fiber-reinforced thermoplastic resin composition of the present invention are obtained by placing a die at the tip of the above-described extruder, and extruding through the die into a gut, tube or sheet shape. Can be manufactured by cutting, specifically, from an extruder,
Those that have been cut with those discharged into gut-form, such as the cross-sectional area 1 to 100 mm ² approximately of spaghetti shaped into substantially a same length as 2 to 50 mm, or the thickness of 1~8mm about sheet side length of those discharged as a 2 One cut into small pieces of about 50 mm or the like can be given. Further, the extruder having a large discharge port may be ejected in a lump or a molded product or the like may be pulverized and formed into a shape that can be molded by a molding method described later.

The fiber-reinforced thermoplastic resin composition of the present invention can be prepared by subjecting pellets or the like obtained by the above production method to injection molding, injection press molding, gas assist molding, tube,
It can be molded by a known molding method such as extrusion molding or blow molding of pipes and sheets, and has better fluidity than the conventional pultrusion method. At the time of molding, in order to suppress breakage of the reinforcing fibers, it is desirable to increase the shape of the nozzle or gate and to set the groove depth of the molding machine screw to be equal to or larger than the pellet size.

Further, the fiber-reinforced thermoplastic resin composition of the present invention takes advantage of its properties to utilize various gears, sensors, connectors, sockets, resistors, switches, coil bobbins, capacitors, plugs, printed circuit boards, tuners, speakers, microphones, Electric and electronic parts such as headphones, motors, magnetic head bases, FDD carriages, FDD chassis, motor brush holders, etc .; TVs, parabolic antennas, VTRs, irons, hair dryers, rice cookers, microwave ovens, audio lasers Audio equipment such as discs and compact discs,
Lighting equipment, refrigerators, air conditioners, washing machines, dryers, typewriters, word processors, computers and other household and office electrical product parts and covers; telephones, facsimile machines, copiers, washing appliances, various motors, helmets , Desks, chairs, and other machinery and tool-related parts and covers; golf driver heads and shafts, kendo trunks, rugby and soccer goals, tennis rackets, hulls and oars, skiing and marine equipment, etc. Sports and leisure related parts and covers; optical instruments and precision machinery related parts and covers represented by microscopes, binoculars, cameras, watches, etc .; furniture, stationery, stationery,
Miscellaneous goods such as toys; building materials represented by window frames, columns, roofing materials, walls, etc .; intake manifolds, air intake nozzle snorkels, fuel pumps, various pipes related to fuel, exhaust / intake systems, cylinder head covers, bumper beams , Seat frame, bumper, instrument panel, wheel cap, wheel cover, tire wheel, battery tray, fuel tank, engine coolant joint, carburetor main body, radiator, door mirror, 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 bay , Wiper motor related parts, Distributor, Starter switch, Starter relay, Transmission system wiring harness, Window shear nozzle, Air conditioner panel switch board, Fuse connector, Horn terminal, Electrical component insulation board, Step motor rotor, Lamp socket, Lamp Automotive and vehicle-related parts and covers such as reflectors, lamp housings, brake pistons, solenoid bobbins, engine oil filters, ignition device cases, etc.
It is useful for various other applications, especially for covers and chassis,
It is suitable for large molded products such as housings.

In order to impart desired properties to the fiber-reinforced thermoplastic resin composition according to the present invention, known materials generally used for thermoplastic resins, for example, antioxidants, heat stabilizers, ultraviolet absorbers Known stabilizers such as agents, antistatic agents, flame retardants, flame retardant aids, coloring agents such as dyes and contents,
Lubricants, plasticizers, crystallization accelerators, nucleating agents and the like can be added or blended. Also, glass flakes,
Fillers such as glass powder, glass beads, silica, montmorillonite, quartz, talc, clay, alumina, carbon black, wollastonite, mica, calcium carbonate, metal powder, wood powder, paper, etc. can be simultaneously compounded. .
There is no particular limitation on the method of addition and blending, and they can be added and blended within a range that does not impair the properties of the composition, and can be added simultaneously with polybutylene terephthalate into the extruder, or simultaneously with the reinforcing fibers inside the extruder. , Or from another inlet, and may be mixed with pellets of the composition of the present invention and then input to a molding machine or the like.

Next, a specific example of the manufacturing method of the present invention will be described with reference to the drawings. FIG. 3 is an overall sectional view of a twin-screw twin-screw extruder preferably used in the present invention.
The thermoplastic resin and the epoxy compound are further supplied, melted while being conveyed by the screw 10 in the extrusion direction, and completely melted in the kneading zone 11. After that, the fibers in the roving state are supplied from the inlet 9 for the reinforcing fibers, and the molten resin and the fibers are sent to the tip of the screw by the screw composed of the full flight 12 having the forward thread. After the fiber is opened and the fiber length is controlled by the control mechanism 13 adjacent to the inlet, the fiber-reinforced thermoplastic resin composition 15 is obtained through a die 14. In addition, it is also possible to form the uneven surface forming portion 17 on the cylinder inner wall 16 corresponding to the screw uneven surface forming portion 13.

[0030]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.
Each mechanical property value shown in Examples and Comparative Examples was measured for 10 samples, and the average value was obtained. Each of the resin compositions was M-50AII-S manufactured by Meiki Seisakusho at a cylinder temperature of 260 ° C, a mold temperature of 80 ° C, and a molding cycle of 25 seconds.
A test piece was molded using a J injection molding machine. At this time, the minimum gauge pressure required to completely fill the cavity of the mold was evaluated, and the minimum molding pressure was used as an index of moldability. Evaluation of Izod impact strength and evaluation of tensile strength are AST respectively.
Measured according to MD-256, ASTM D-638. For hydrolyzability, see PRESSURE C manufactured by Tabai Co., Ltd.
After 120 hours (5 days) of hydrolysis treatment at 121 ° C. and 100% RH with OOKER TPC-411, the tensile strength was measured to determine the strength retention.

The fibers in the pellets and the molded article were observed by burning each sample in a 500 ° C. electric furnace with only the thermoplastic resin, and measuring the fiber content. In addition, the fibers of the ash were observed with a microscope, and the lengths of arbitrary 500 fibers were measured to obtain a weight average fiber length (Lw) and a number average fiber length (Ln).
(Lw / d) and (Lw / Ln) were determined.

The polybutylene terephthalate and epoxy compound used in this experiment are shown below.

Polybutylene terephthalate A-1: COOH terminal group 40 eq / t, intrinsic viscosity 0.8
8 A-2: COOH terminal group 9 eq / t, intrinsic viscosity 1.3
0 A-3: COOH terminal group 70 eq / t, intrinsic viscosity 0.5
5

Epoxy compound C-1: Hexahydrophthalic acid diglycidyl ester (Epicoat-191P) (epoxy equivalent: 170) Yuka Shell Epoxy C-2: Terephthalic acid diglycidyl ester (Denacol EX-711) (epoxy equivalent) 149) Nagase & Co., Ltd. C-3: Bisphenol-A-diglycidyl ether (Epicoat-819) (epoxy equivalent: 200) Yuka Shell Epoxy C-4: Mixture of bisphenol-A-diglycidyl ether and butyl glycidyl ether (Epicoat-81
5) (Epoxy equivalent: 185) C-5: glycidyl ester ether of p-hydroxybenzoic acid (UQ-103) manufactured by Yuka Shell Epoxy (epoxy equivalent: 16)
1) Ueno Pharmaceutical

Examples 1 to 5 As shown in FIG. 3, using a twin screw extruder (TEX30 manufactured by Nippon Steel Works Co., Ltd.) having a screw diameter of 30 mm and L / D35 having two supply ports in the extrusion direction. A screw element consisting of five kneading disks inclined at 45 degrees with L / D = 1 between the first resin supply port and the reinforcing fiber input port using screws of 3.5 mm meshed with each other with a thread screw. Are provided in combination in the reverse order, and a full-flight screw of L / D = 1 is provided on the discharge side of the reinforcing fiber input port. (Pitch: 1 mm, cutting edge angle: 30 degrees, height of peaks and valleys: 1 mm) Using a machine equipped with a machined L / D = 1 and a screw provided with an elliptical cross-section deformed surface, shown in Table 1. Polybutylene terephthalate and an epoxy compound are supplied to a first supply port by a screw-type pellet supply device so that the ratio becomes the same ratio, and a glass roving of 13 μm in diameter and 1100 g per 1000 m (Nippon Electric Glass Co., Ltd.) Made)
Extruded into a strand at a cylinder temperature of 260 ° C and a screw rotation speed of 200 rpm, cooled in a water bath,
The resultant was cut into lengths to obtain fiber-reinforced thermoplastic resin pellets. The fiber reinforced thermoplastic resin pellets were dried at 110 ° C. for 8 hours and then injection molded.

Comparative Example 1 Using the polybutylene terephthalate shown in Table 2, a fiber-reinforced thermoplastic resin composition was prepared in the same apparatus and in the same manner as in Example 1, and molded and evaluated in the same manner.

Comparative Example 2 The same apparatus as in Example 1 except that a screw element composed of five kneading disks inclined at 45 degrees with L / D = 0.75 was also provided on the discharge side of the reinforcing fiber inlet. And the same polybutylene terephthalate and epoxy compound as in Example 1 were supplied, and the same fiber reinforced fiber of chopped strand type in which the same glass roving as in Example 1 was cut to a length of 3 mm was used as the reinforcing fiber, and a known fiber reinforcement was used. Extruded into strands by the method for producing thermoplastic resin pellets, cooled in the same manner as in Example 1, cut to a length of 4 mm to obtain fiber-reinforced thermoplastic resin pellets having a glass fiber content of 30 parts by weight, and then dried. Injection molding was performed in the same manner as in Example 1.

Comparative Example 3 Using the same polybutylene terephthalate, epoxy compound and glass roving as in Example 2, a pellet length of 5 was obtained by a known crosshead die-type pultrusion method.
to obtain a long fiber reinforced pellet having a glass content of 45 parts by weight. After drying in the same manner as in Example 1 as in Comparative Example 1, injection molding was performed.

As shown in Table 1, in Examples of the present invention, a fiber-reinforced thermoplastic resin composition excellent in mechanical properties, hydrolyzability and moldability was obtained. Among them, in Example 4, since the intrinsic viscosity of polybutylene terephthalate was high, the fiber length was slightly shortened and the mechanical properties were slightly lowered. In addition, in Example 5, although the fiber length was long, the intrinsic viscosity of polybutylene terephthalate was small, so that the mechanical properties were slightly low. As shown in Table 2, the thermal characteristics of Comparative Example 1 containing no epoxy compound were poor. In Comparative Example 2, the fiber length in the molded article was short, and a sufficient reinforcing fiber could not provide a reinforcing effect, resulting in poor mechanical properties. In Comparative Example 3 prototyped by the pultrusion method, although excellent mechanical properties were obtained, the dispersion was large and the moldability was poor.

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

As apparent from the above description and Examples, the fiber-reinforced thermoplastic resin composition of the present invention comprising polybutylene terephthalate, a reinforcing fiber and an epoxy compound and having a specific fiber length and a specific fiber length distribution is provided. The method for producing a fiber-reinforced thermoplastic resin composition that excels in moldability, mechanical properties, and hydrolyzability during various moldings, and further controls the degree of fiber opening, fiber length, and fiber length distribution of the reinforcing fiber, It is also highly industrial and of very high industrial value.

[Brief description of the drawings]

FIG. 1a is a perspective view of a screw which has been subjected to a preferred blade-like processing according to the present invention, and FIG. 1b is a cut-away perspective view of a cylinder which has been subjected to a preferred blade-like processing according to the present invention.

FIG. 2 is a conceptual cross-sectional side view in which the blade-shaped portion of the screw or cylinder subjected to the blade-shaped processing shown in FIG. 1 is enlarged.

FIG. 3 shows two supply ports preferably used in the present invention.
FIG. 2 is an overall cross-sectional view of the extruder provided with the above.

[Explanation of symbols]

 θ. Edge angle t. Pitch h. Height of summit and valley bottom Screw with blade-like processing part 2. Screw edge processing part 3. 3. Cylinder having an edge-shaped part 4. Edge processing part of cylinder inner wall Screw full flight section 6. Flight surface 7. 7. Cylinder inner wall First supply port 9. Second supply port (reinforced fiber input port) 10. Screw 11. Kneading zone 12. 12. Full flight of forward screw Screw uneven surface forming part 14. Dice 15. Fiber reinforced thermoplastic resin strand 16. Cylinder inner wall 17. Cylinder inner wall uneven surface forming part

Claims (7)

[Claims] (A) polybutylene terephthalate,
In a fiber-reinforced thermoplastic resin composition containing (B) a reinforcing fiber and (C) an epoxy compound, the weight average fiber length (Lw) and the fiber diameter (d) of the (B) reinforcing fiber in the composition are determined. A fiber reinforced thermoplastic resin having a relationship (Lw / d) of 50 to 250 and a ratio (Lw / Ln) of the number average fiber length (Ln) to the weight average fiber length (Lw) of 1.1 to 3.5. Composition. 2. The components (A) and (B) are added in an amount of (A) 40 to 99% by weight of polybutylene terephthalate and (B) reinforcing fibers 1 to 60 with respect to the total of (A) and (B). The fiber-reinforced thermoplastic resin composition according to claim 1, wherein the epoxy compound (C) is 2.5 parts by weight or less based on 100 parts by weight of the total of (A) and (B). 3. The method according to claim 1, wherein (A) polybutylene terephthalate is C
OOH terminal group 10-60 eq / t, intrinsic viscosity 0.60
1.25 polybutylene terephthalate.
Or the fiber-reinforced thermoplastic resin composition according to 2. 4. The method according to claim 1, wherein (A) polybutylene terephthalate is C
OOH terminal group 20-55 eq / t, intrinsic viscosity 0.65-
The polybutylene terephthalate of 1.10.
4. The fiber-reinforced thermoplastic resin composition according to any one of items 3 to 3. 5. The fiber-reinforced heat according to claim 1, wherein (C) the epoxy compound is at least one selected from a compound having a glycidyl ester, a compound having a glycidyl ether, and glycidyl ester and glycidyl ether. Plastic resin composition. 6. A pellet comprising the fiber-reinforced thermoplastic resin composition according to claim 1. 7. An extruder having at least a part of a screw and / or a cylinder having a surface opening / fiber length control mechanism in which a surface is deformed is used, and polybutylene terephthalate of component (A) and (C) are used. While melting the epoxy compound as the component, the reinforcing fiber of the component (B) in a continuous state is supplied into the polybutylene terephthalate in the molten state, and the reinforcing fiber is passed while passing through the opening / fiber length control mechanism. Claims 1 to 1 by opening the fiber and controlling the fiber length.
5. A method for producing a fiber-reinforced thermoplastic resin composition, comprising producing the fiber-reinforced thermoplastic resin composition according to any one of the above items 5.