JP2012046684A - Polybutylene terephthalate resin composition and molded product obtained by molding the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polybutylene terephthalate resin composition suppressing breakage of reinforcing fibers and easily obtaining highly rigid and high strength molded products.SOLUTION: The polybutylene terephthalate resin composition is composed of 100 pts.wt. of a polybutylene terephthalate resin and 30-150 pts.wt. of a molding material, having at least the following structural element [A], [B] and [C], wherein the element [C] is disposed so as to come into contact with a composite body having the structural element [A] and the structural element [B]. The [A] is a reinforcing fiber bundle; the [B] is a thermoplastic resin having the weight-average molecular weight of 200-50,000 and the melt viscosity lower than that of the structural element [C]; and the [C] is a polyolefin resin having the weight-average molecular weight of 10,000 or higher.

Description

  The present invention relates to a polybutylene terephthalate resin composition, a molded product obtained by molding it, and a method for producing the same.

  It is known to improve strength by filling a polybutylene terephthalate with a fibrous filler. However, the fibrous filler may break due to shear during melt processing, and the strength improvement effect may be reduced. For this reason, as a manufacturing method of the fiber reinforced thermoplastic resin excellent in rigidity strength and impact resistance, for example, the first thermoplastic resin containing fibers and the flow start temperature or the melting temperature of the first resin. The low second resin is heated above the flow start temperature or melting temperature of the second resin and then heated above the flow start temperature or melting temperature of the first resin, so that the first resin and the second resin are heated. And a method comprising a melt-mixing step in which fibers are uniformly mixed and a forming step are disclosed (for example, see Patent Document 1). In addition, as a method for producing a thermoplastic resin molded product reinforced with long fibers, for example, a dry blend of a long fiber-containing thermoplastic resin and a thermoplastic resin that does not contain long fibers that are the same or compatible with this resin, A method of injection or extrusion molding (see, for example, Patent Document 2) has been proposed. In addition, as a molding material that is easy to manufacture and has good dispersion of reinforcing fiber bundles, at least [A] continuous reinforcing fiber bundles, [B] has a weight average molecular weight of 200 to 50,000, and is less than [C] described later. A thermoplastic polymer having a low melt viscosity, [C] a thermoplastic resin having a weight average molecular weight of 10,000 or more, and arranged such that [C] is in contact with a composite composed of [A] and [B]. The molding material (for example, refer patent document 3) is disclosed.

JP-A-1-286824 JP-A-1-241406 Japanese Patent Laid-Open No. 10-138379

  Since polybutylene terephthalate resin has excellent heat resistance, moldability, chemical resistance and electrical insulation, it has been used in various applications in recent years. In recent years, there has been a demand for molding materials with higher strength. However, when the methods of Patent Documents 1 and 2 are applied to a polybutylene terephthalate resin composition, the compatibility between the reinforcing fibers and the polybutylene terephthalate resin is insufficient. In addition, since the dispersibility is insufficient, the reinforcing fibers are localized, and it is difficult to obtain a sufficient reinforcing effect by the reinforcing fibers.

  Therefore, an object of the present invention is to provide a polybutylene terephthalate resin composition that solves the above-described problems, suppresses breakage of reinforcing fibers, and can easily obtain a molded product having high rigidity and high strength.

In order to solve the above problems, the present invention has the following configuration.
1. The composite having at least the following components [A], [B] and [C] and having the components [A] and [B] with respect to 100 parts by weight of the polybutylene terephthalate resin, A polybutylene terephthalate resin composition comprising 30 to 150 parts by weight of a molding material arranged so that [C] is in contact therewith.
[A] Reinforcing fiber bundle [B] A thermoplastic resin having a weight average molecular weight of 200 to 50,000 and a melt viscosity lower than that of component [C] [C] A polyolefin resin having a weight average molecular weight of 10,000 or more.
2. A molded product having a sea-island structure obtained by molding the polybutylene terephthalate resin composition according to 1 above, having a sea containing at least a polybutylene terephthalate resin, and an island containing the component [C], A molded article, wherein the component [A] is present in the island.
3. At least the polybutylene terephthalate resin and the molding material having the constituent elements [A], [B] and [C] are dry-blended and directly injection-molded or extruded without a melt-kneading step. 2. A method for producing a molded article according to 2.

  In the polybutylene terephthalate resin composition of the present invention, breakage of reinforcing fibers is suppressed, and a molded product having high rigidity and high strength can be obtained by molding such a resin composition.

Scanning electron microscope (SEM) observation photograph of the cross section of the test piece for impact resistance evaluation obtained in Example 1 SEM observation photograph of cross section of test piece for impact resistance evaluation obtained in Comparative Example 3

  The polybutylene terephthalate resin composition of the present invention contains 30 to 150 parts by weight of a specific reinforcing fiber bundle-containing molding material described later with respect to 100 parts by weight of the polybutylene terephthalate resin.

  The polybutylene terephthalate resin used in the present invention is a polymer obtained by a polycondensation reaction between terephthalic acid or an ester-forming derivative thereof and 1,4-butanediol or an ester-forming derivative thereof. Along with terephthalic acid or its ester-forming derivatives, isophthalic acid, naphthalenedicarboxylic acid, adipic acid, sebacic acid, dodecanedioic acid, oxalic acid or ester-forming derivatives thereof may be copolymerized, or 1,4-butanediol Or together with its ester-forming derivatives, ethylene glycol, propylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, polyethylene glycol having a molecular weight of 400 to 6000 Poly-1,3-propylene glycol, polytetramethylene glycol or ester-forming derivatives thereof may be copolymerized. These copolymer components are preferably 20 mol% or less. Preferable examples of the polybutylene terephthalate resin include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decane dicarboxylate), polybutylene (terephthalate / Naphthalate). Two or more of these may be contained. “/” Means copolymerization.

  The polybutylene terephthalate resin preferably has an intrinsic viscosity in the range of 0.36 to 3.0 measured at 25 ° C. using an o-chlorophenol solvent in accordance with JIS K7367-5 (2000). The moldability of the composition is excellent, and the impact resistance of the molded product can be improved. A range of 0.42 to 2.0 is more preferable. Two or more kinds of polybutylene terephthalate resins having different intrinsic viscosities may be contained, and in that case, the intrinsic viscosities of all the polybutylene terephthalate resins are preferably in the above-mentioned range.

  The polybutylene terephthalate resin preferably has a small amount of COOH end groups from the viewpoint of durability and anisotropy suppressing effect. Specifically, the amount of COOH end groups per ton of polybutylene terephthalate resin is preferably in the range of 1 to 50 eq / t. Here, the amount of COOH end groups of the polybutylene terephthalate resin can be determined by potentiometric titration of the m-cresol solution with an alkaline solution.

  The polybutylene terephthalate resin composition of the present invention comprises at least a component [A] reinforcing fiber bundle, [B] a thermoplastic resin having a weight average molecular weight of 200 to 50,000 and a melt viscosity lower than that of the component [C], and [C] Molding comprising a polyolefin resin having a weight average molecular weight of 10,000 or more, and being arranged so that the component [C] is in contact with a composite having the component [A] and the component [B]. 30 to 150 parts by weight of the material (reinforced fiber bundle-containing molding material) is included. The component [A] imparts high rigidity and strength to the molded product as a composite reinforcing material. The component [C] is a matrix resin having a relatively high viscosity and high physical properties such as toughness. The constituent element [C] has a role of impregnating the constituent element [A] during the molding of the polybutylene terephthalate resin composition and firmly holding the reinforcing fibers. The component [B] is a thermoplastic polymer having a relatively low viscosity and forms a composite with the component [A]. At the time of molding the polybutylene terephthalate resin composition, the component [B] ) Helps to impregnate the reinforcing fiber bundle (component [A]), and also helps to disperse the reinforcing fiber in the matrix resin.

  The reinforcing fiber constituting the reinforcing fiber bundle used as the component [A] is not particularly limited. For example, high-strength and high-modulus fibers such as carbon fiber, glass fiber, polyaramid fiber, alumina fiber, silicon carbide fiber, and boron fiber can be used. You may have 2 or more types of these. Among these, carbon fibers are preferable because they are more excellent in improving rigidity and strength.

  The component [B] is a thermoplastic polymer having a weight average molecular weight of 200 to 50,000 and a melt viscosity lower than that of the component [C]. The component [A] is impregnated into the component [A]. Form. The component [B] is impregnated or reinforced into the matrix resin when the reinforcing fiber bundle (component [A]) is impregnated with the matrix resin (component [C]), which is a high viscosity thermoplastic resin. It functions as an impregnation aid / dispersion aid that aids fiber dispersion. That is, the reinforcing fiber bundle (component [A]) is pre-impregnated with a thermoplastic resin (component [B]) having a lower melt viscosity than the component [C], for example, injection molding or press molding. When the polybutylene terephthalate resin composition is subjected to temperature, pressure, and kneading in the molding process to a final shape such as, the matrix resin (component [C]) becomes a reinforcing fiber bundle (component [A]). It can help to impregnate and improve the dispersibility of the reinforcing fibers in the matrix resin.

  When the weight average molecular weight of the component [B] is smaller than 200, it may easily cause volatilization due to heat in the molding process, which may cause defects such as voids in the molded product. Further, mechanical properties such as impact resistance of the matrix resin after molding are lowered. Conversely, when the weight average molecular weight of the constituent element [B] is larger than 50,000, the melt viscosity of the constituent element [B] becomes high and impregnation into the reinforcing fiber bundle becomes difficult, so the productivity of the molding material is lowered. To do. 14,000 or less is preferable and 1,000 or less is more preferable.

  The weight average molecular weight of the component [B] can be measured by gel permeation chromatography (GPC), and a low angle light scattering photometer (LALLS) using a laser as a detector is used.

  The melt viscosity of component [B] can be determined with a capillary rheometer, and is preferably 7 Pa · s or less at 260 ° C. In addition, the relationship between the melt viscosity of the component [B] and the component [C] is sufficient if the melt viscosity of the component [B] is smaller than the melt viscosity of the component [C] at the molding temperature.

  As the constituent element [B], an oligomer obtained by condensation of phenol or a substituent derivative of phenol (precursor a) and an aliphatic hydrocarbon having two double bonds (precursor b) is preferably used. The condensation reaction can be carried out in the presence of a strong acid or a Lewis acid. In addition, an oligomer obtained by reacting the precursor a with a compound that generates the precursor b in the system under the same conditions is also preferably used.

  As the substituent derivative of phenol, one having 1 to 3 substituents selected from an alkyl group, a halogen atom, and a hydroxyl group on the benzene nucleus of phenol is preferably used. Specific examples thereof include cresol, xylenol, ethylphenol, butylphenol, t-butylphenol, nonylphenol, 3,4,5-trimethylphenol, chlorophenol, bromophenol, chlorocresol, hydroquinone, resorcinol, orcinol and the like. .

Examples of the precursor b include an aliphatic hydrocarbon having no cyclic structure such as butadiene, isoprene, pentadiene, and hexadiene, and a molecular formula of cyclohexadiene, vinylcyclohexene, cycloheptadiene, cyclooctadiene, and C ₁₀ H _16. Monocyclic monoterpenes (dipentene, limonene, terpinolene, terpinene, ferrandylene) and the like, bicyclic sesquiterpenes represented by the molecular formula of 2,5-norbornadiene, tetrahydroindene, C ₁₅ H ₂₄ Examples thereof include aliphatic hydrocarbons having a cyclic structure such as bicyclic compounds (such as kadinene, serine, and caryophyllene) and tricyclic compounds such as dicyclopentadiene.

  Component [C] is a polyolefin resin having a weight average molecular weight of 10,000 or more. When the weight average molecular weight is less than 10,000, the rigidity and strength of the finally obtained molded product are lowered. The component [C] is not particularly limited as long as the weight average molecular weight is 10,000 or more. Examples of the polyolefin resin include polyethylene, polypropylene, and propylene / ethylene block copolymer, and propylene / ethylene block copolymer is more preferable.

  The weight average molecular weight of the component [C] can be measured by gel permeation chromatography (GPC), and a low angle light scattering photometer (LALLS) using a laser as a detector is used.

  The melt viscosity of the component [C] can be determined with a capillary rheometer, and is preferably 40 Pa · s or more at 260 ° C.

  The molding material used for the polybutylene terephthalate resin composition of the present invention is arranged such that the component [C] is in contact with the composite having the component [A] and the component [B]. The component [C] is arranged so as to cover the periphery of the complex having the component [A] and the component [B], or the complex and the component [C] are arranged in layers. The configuration is preferable. When the molding material is plasticized during molding of the polybutylene terephthalate resin composition by arranging the composite of component [A] and component [B] in contact with component [C], reinforcing fibers Can be easily dispersed in the matrix resin, and as a result, the reinforcing fibers can be uniformly and well dispersed in the molded product.

  The content of the component [A] in the molding material is preferably 10 parts by weight or more, more preferably 15 parts by weight or more with respect to 100 parts by weight of the component [C] in order to further improve the strength and rigidity of the molded product. More preferably, 20 parts by weight or more is more preferable. On the other hand, from the viewpoint of adjusting the melt viscosity of the resulting polybutylene terephthalate resin composition to an appropriate range, 100 parts by weight or less is preferable, 80 parts by weight or less is more preferable, and 60 parts by weight or less is more preferable.

  The content of the component [B] in the molding material is preferably 1 part by weight or more with respect to 100 parts by weight of the component [C] in order to further enhance the effect as an impregnation aid, and more preferably 2 parts by weight or more. Preferably, 3 parts by weight or more is more preferable. On the other hand, from the viewpoint of reducing the amount of gas generated during the molding process, 20 parts by weight or less is preferable, 15 parts by weight or less is more preferable, and 10 parts by weight or less is more preferable.

  The above-mentioned reinforcing fiber bundle-containing molding material is preferably used after being cut to a length of 1 to 50 mm. By using such a length, the fluidity of the polybutylene terephthalate resin composition is improved, and the shapeability at the time of molding is greatly improved. As the cutting length is shorter, the moldability such as formability and fluidity increases, but 1 mm or more is preferable and 3 mm or more is more preferable from the viewpoint of the effect of improving the strength of the molded product by the reinforcing fibers. Moreover, from a viewpoint of a moldability, 50 mm or less is preferable and 12 mm or less is more preferable.

  In the polybutylene terephthalate resin composition of the present invention, the content of the above-mentioned reinforcing fiber bundle-containing molding material is 30 to 150 parts by weight. When the content of the reinforcing fiber bundle-containing molding material is less than 30 parts by weight, the amount of reinforcing fiber bundle is reduced, and the strength and rigidity of the molded product are lowered. 50 parts by weight or more is preferable, and 70 parts by weight or more is more preferable. Further, when the amount exceeds 150 parts by weight, the amount of the constituent element [C] relatively increases, and it becomes difficult to form a sea-island structure to be described later in the molded product, and the strength and rigidity are lowered.

  Depending on the required properties, the polybutylene terephthalate resin composition can contain flame retardants, weather resistance improvers, antioxidants, heat stabilizers, UV absorbers, plasticizers, lubricants, colorants, compatibilizers, conductive fillers, etc. You may contain.

  The polybutylene terephthalate resin composition can be produced by melt-kneading the polybutylene terephthalate and the reinforcing fiber bundle-containing molding material using a kneader such as an extruder. However, as will be described later, when a melt-kneading step using an extruder or the like is performed, breakage of the reinforcing fibers may occur and the strength of the molded product may be reduced. After dry blending, it is preferable to produce a molded product to be described later by direct injection molding or extrusion molding without providing a melt-kneading step.

  Next, the molded product of the present invention will be described. The molded article of the present invention is a molded article having a sea-island structure obtained by molding the polybutylene terephthalate resin composition described above, and includes the sea containing at least the polybutylene terephthalate resin and the component [C]. It is preferable to have an island and the component [A] is present in the island.

  Although it is difficult to disperse the reinforcing fiber bundle (component [A]) that has been converged directly into the sea containing the polybutylene terephthalate resin by a conventionally known technique, in the present invention, the reinforcing fiber bundle ( Since component [A]) is well dispersed in polyolefin resin (component [C]), it is included in component [C] by dispersing islands of component [C] in polybutylene terephthalate resin. The component [A] is dispersed in the island, and as a result, the component [A] is well dispersed in the sea of the polybutylene terephthalate resin, and high rigidity and high strength can be expressed.

  The molded article of the present invention is preferably obtained by mechanically mixing and stirring at least the above-mentioned polybutylene terephthalate resin and the reinforcing fiber bundle-containing molding material, followed by injection molding or extrusion molding. By directly forming without passing through the melt-kneading step with an extruder or the like, breakage of the reinforcing fibers can be suppressed as much as possible, and the fiber length can be kept long. Examples of the molding method include press molding, transfer molding, injection molding, and combinations thereof.

  The molded article of the present invention is suitably used for small parts such as cylinder head covers, bearing retainers, intake manifolds, automobile parts such as pedals, tools such as monkeys and wrenches, and gears. Moreover, since the polybutylene terephthalate resin composition of the present invention is excellent in fluidity, a thin molded product having a thickness of about 0.5 to 2 mm can be obtained relatively easily. Examples of such thin-walled molded articles include personal computer and mobile phone casings, and members for electric and electronic devices such as a keyboard support that is a member that supports the keyboard inside the personal computer. It is done. In such a member for electric / electronic devices, when carbon fiber having conductivity is used as the reinforcing fiber, electromagnetic wave shielding properties are imparted, which is more desirable.

  Hereinafter, the effect of the present invention will be described in more detail with reference to examples. The materials used in each example and comparative example are shown below.

(1) Polybutylene terephthalate resin “Toraycon (registered trademark)”-1100M manufactured by Toray Industries, Inc.

(2) Reinforcing fiber bundle-containing molding material It was produced by the method described in Reference Example 1 below.
[Reference Example 1] Method for Producing Reinforced Fiber Bundle-Containing Molding Material Using a kiss coater on a roll heated to 130 ° C, a terpene phenol polymer (monocyclic monoterpene and phenol adduct, manufactured by Yasuhara Chemical Co., Ltd.) A liquid film obtained by heating and melting YP90L, a weight average molecular weight of 460, and a melt viscosity at 260 ° C. (shear rate of 1000 s ⁻¹ ) of 0.5 Pa · s was formed. A continuous carbon fiber bundle ("Torayca (registered trademark)" T700SC, 12,000 carbon fibers, single fiber fineness 0.6 denier) manufactured by Toray Industries, Inc. is passed through the roll while contacting the carbon fiber bundle. A certain amount of terpene phenol polymer was deposited per unit length of bundle.

The carbon fiber to which the terpene phenol polymer was adhered was alternately passed over 10 rolls having a diameter of 10 mm, which were heated to 180 ° C. and freely rotated by bearings, which were arranged in a straight line. By this operation, the polymer was impregnated to the inside of the fiber bundle to form a continuous composite made of carbon fiber and terpene phenol polymer. This continuous composite was passed through a coating die for wire coating installed at the tip of a single screw extruder having a diameter of 40 mm, and a polyolefin resin (propylene / ethylene block) melted at 240 ° C. from the extruder into the die. A copolymer, a weight average molecular weight of 180,000, melt viscosity at 260 ° C. (shear rate 1000 s ⁻¹ ) 200 Pa · s) was discharged, and a polyolefin resin was continuously arranged so as to cover the periphery of the composite.

  A molding material obtained by coating this composite with a polyolefin resin was cooled to near room temperature, and then cut into a length of 7 mm by a strand cutter to obtain pellets for injection molding. The material production up to this point was performed in a continuous process, and the take-up speed of the carbon fiber bundle was 30 m / min. The composition ratio of this molding material was carbon fiber: terpene phenol polymer: polypropylene resin = 30: 6: 64 (weight ratio).

  The weight average molecular weights of the terpene phenol polymer and the polyolefin resin were measured by gel permeation chromatography (GPC) by dissolving them in o-dichlorobenzene, and a low angle light scattering light intensity using a laser as a detector. A meter (LALLS) was used. The apparatus used was “HSS-2000” manufactured by JASCO Corporation, and the detector used was RI-2031plus (JASCO).

(3) Polyolefin resin propylene / ethylene block copolymer: weight average molecular weight 180,000, melt viscosity at 260 ° C. 200 Pa · s

(4) Carbon fiber "Torayca" T700S-12K-30E manufactured by Toray Industries, Inc.

(5) Other materials Manufactured by the method described in Reference Example 2 below.
[Reference Example 2]
A carbon fiber bundle ("Torayca" T700SC manufactured by Toray Industries, Inc., 12,000 carbon fibers, single fiber fineness 0.6 denier) is installed for the wire coating method installed at the tip of a single screw extruder having a diameter of 40 mm. Polybutylene terephthalate resin ("Toraycon" -1100M manufactured by Toray Industries, Inc.) melted at 260 ° C in the die is discharged from the extruder and discharged to coat the periphery of the carbon fiber. Butylene terephthalate resin was continuously arranged.

  A molding material obtained by coating the carbon fiber with a polybutylene terephthalate resin was cooled to near room temperature, and then cut into a length of 7 mm by a strand cutter to obtain pellets for injection molding. The material production up to this point was performed in a continuous process, and the take-up speed of the carbon fiber bundle was 30 m / min. The composition ratio of the molding material was carbon fiber: polybutylene terephthalate resin = 30: 70 (weight ratio).

  Moreover, the evaluation method of each characteristic is as follows.

1. Bending characteristic evaluation Using an IS55EPN injection molding machine manufactured by Toshiba Machine, a test piece for evaluation having a thickness of 4 mm was injection molded under the conditions of a molding temperature of 260 ° C and a mold temperature of 80 ° C. Flexural strength and flexural modulus were measured according to ISO178.

2. Impact Resistance Evaluation Using an IS55EPN injection molding machine manufactured by Toshiba Machine, a test piece for evaluation having a thickness of 4 mm was injection molded under the conditions of a molding temperature of 260 ° C. and a mold temperature of 80 ° C. Charpy impact strength (notched) was measured according to ISO179.

3. Measurement of Weight Average Fiber Length Using a Toshiba Machine IS55EPN injection molding machine, a test piece for evaluation having a thickness of 4 mm was injection molded under the conditions of a molding temperature of 260 ° C. and a mold temperature of 80 ° C. This test piece was put into an electric furnace and baked at 500 ° C. for 5 hours to remove the polymer component. The remaining reinforcing fibers were dispersed on the microscope slide glass so that the fibers did not pile up, and micrographs were taken at a magnification of 800 times. The length of 100 or more fibers randomly selected from the micrograph was measured, and the weight average value was obtained.

4). 1. Compatibility evaluation The cross section of the test piece after the evaluation used in the impact resistance evaluation was observed with a scanning electron microscope (SEM) (“JSM-6360LV” manufactured by JEOL Ltd.) at a magnification of 500 times. As shown in FIG. 1, if the resin was adhered around the reinforcing fiber, the compatibility between the reinforcing fiber and the resin was evaluated as good. If resin did not adhere around the reinforcing fiber as shown in FIG. 2, the compatibility between the reinforcing fiber and the resin was evaluated as poor.

[Examples 1 to 3]
The polybutylene terephthalate resin and the reinforcing fiber bundle-containing molding material produced in [Reference Example 1] were dry blended at a blending ratio shown in Table 1. In order to simply evaluate the bending characteristics, impact resistance, fiber length in the molded product, and compatibility, the test piece was obtained from the obtained polybutylene terephthalate resin composition by the method described in items 1 to 4 above. Molded and evaluated by the method described above. Table 1 shows the results.

  Further, after cutting a test piece for impact resistance evaluation and ruthenium-staining the cross section, it was scanned with a scanning electron microscope (SEM) (“JSM-6360LV” manufactured by JEOL Ltd.) at a magnification of 2,000 times. As a result of the observation, in any of the examples, the polybutylene terephthalate resin is the sea, the polyolefin resin has an island-island structure, and the carbon fiber is present in the polyolefin resin island. It could be confirmed.

[Comparative Examples 1-4]
Except for changing the composition as shown in Table 1, the bending characteristics, impact resistance, fiber length and compatibility were evaluated in the same manner as in Examples 1 to 3. Table 1 shows the results.

  Further, after cutting a test piece for impact resistance evaluation and ruthenium-staining the cross section, it was scanned with a scanning electron microscope (SEM) (“JSM-6360LV” manufactured by JEOL Ltd.) at a magnification of 2,000 times. As a result of observation, in Comparative Example 1, it was confirmed that the polybutylene terephthalate resin was the sea, the polyolefin resin had an island-island structure, and the carbon fiber was present in the polyolefin resin island. However, in Comparative Example 2, the polyolefin resin was the sea and the polybutylene terephthalate resin was an island-island structure, and it was confirmed that the carbon fiber was present in the polyolefin resin sea. In Comparative Example 3, the polybutylene terephthalate resin was the sea and the polyolefin resin was an island-island structure, but it was confirmed that the carbon fiber was present on both the sea and the island. In Comparative Example 4, the polyolefin resin was the sea and the polybutylene terephthalate resin had an island-island structure, but it was confirmed that the carbon fiber was present on both the sea and the island.

  As can be seen from Table 1, the polybutylene terephthalate resin compositions of Examples 1 to 3 of the present invention have longer reinforcing fibers than the polybutylene terephthalate resin compositions shown in Comparative Examples 1 to 4. Thus, a molded product having high rigidity and high strength was obtained.

  The scanning electron microscope (SEM) observation photograph of the cross section of the test piece for impact resistance evaluation obtained by Example 1 and Comparative Example 3 is shown in FIGS.

Claims (3)

The composite having at least the following components [A], [B] and [C] and having the components [A] and [B] with respect to 100 parts by weight of the polybutylene terephthalate resin, A polybutylene terephthalate resin composition comprising 30 to 150 parts by weight of a molding material arranged so that [C] is in contact therewith.
[A] Reinforcing fiber bundle [B] Thermoplastic resin having a weight average molecular weight of 200 to 50,000 and lower melt viscosity than component [C] [C] Polyolefin resin having a weight average molecular weight of 10,000 or more A molded article having a sea-island structure obtained by molding the polybutylene terephthalate resin composition according to claim 1, comprising a sea containing at least a polybutylene terephthalate resin and an island containing the component [C]. The molded product, wherein the component [A] is present in the island. 2. A dry blend of at least the polybutylene terephthalate resin and a molding material having the constituent elements [A], [B] and [C], and direct injection molding or extrusion molding without providing a melt-kneading step. Item 3. A method for producing a molded article according to Item 2.

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