JP2006298993A - Polybutylene terephthalate resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polybutylene terephthalate resin composition which retains a high stiffness, is excellent in impact strength and rupture elongation and is suitable for a connector etc. <P>SOLUTION: The polybutylene terephthalate resin composition is obtained by compounding 1-30 pts.wt. polyester-ether thermoplastic elastomer (B) with 100 pts.wt. polybutylene terephthalate resin (A), wherein the thermoplastic elastomer (B) comprises an aromatic polyester block and an aliphatic polyether block. The aliphatic polyether block comprises a polyalkylene ether glycol with a weight average molecular weight of 400-6,000 as a unit and accounts for 25-80 wt.% of (B). Transmission electron microscopy of the resin composition reveals a sea-island structure, wherein (A) and (B) are the sea and the island, respectively, and the average diameter of the island part containing the polyalkylene ether glycol component is 0.05-0.30 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polybutylene terephthalate resin composition excellent in impact strength and tensile elongation while maintaining a high elastic modulus.

Thermoplastic polybutylene terephthalate resin (hereinafter, sometimes abbreviated as PBT resin), the mechanical properties, electrical properties, excellent other physical and chemical properties, and workability Ri excellent der, engineering plastics It is used in a wide range of applications such as automobiles, electrical / electronic parts, etc. However, there is a problem that the mechanical strength is inferior at a low temperature. For example, when bending deformation is applied at a low temperature, there may be a trouble that the strain is broken when the amount of strain is small. Specifically, in the connector that fixes the terminal by snap characteristics such as a lance, troubles such as breakage of the lance portion occur at low temperatures, and the use and shape of the molded product are considerably limited. is the current situation.

  In order to improve the above-described problem of mechanical strength at low temperatures, a resin having good flexibility, particularly a thermoplastic elastomer, is added to the PBT resin. For example, from the viewpoint of compatibility with a PBT resin, various studies have been made on alloying with a polyester-based thermoplastic elastomer.

  Patent Document 1 includes (1) a thermoplastic aromatic polyester such as PBT resin, and (2) a polyester block copolymer having a recrystallization temperature exceeding 150 ° C., preferably an aromatic polyester block and an aliphatic polyester block. A polymer composition comprising a second polymer that is a plastic elastomer, wherein the weight ratio of the second polymer (2) to the aromatic polyester (1) is 0.05: 1 to 0.35: 1 is shown. ing. In Patent Document 2, an inorganic filler is added to a polyester (mixture) composed of 100 to 20% by weight of a thermoplastic polyester elastomer and 0 to 80% by weight of a PBT resin containing a polyester-type or polyether-type soft component. It is disclosed that an insert-molded product formed by insert-molding a blended resin composition and a component such as metal improves high-temperature shock resistance (heat shock resistance).

  However, the impact strength is improved by alloying with polyester-based thermoplastic elastomers, but the elastic modulus decreases, and there is a concern that the connector's fitting strength cannot be fully exhibited. In applications where maintaining the modulus is also important, lowering the elastic modulus can cause concerns about connector mating.

Japanese National Patent Publication No. 11-504365 JP-A-9-262863

  An object of the present invention is to provide a polybutylene terephthalate resin composition excellent in impact strength and elongation at break while maintaining a high elastic modulus, for example, in a connector for fixing a terminal by snap characteristics such as a lance. Providing a polybutylene terephthalate resin composition and a molded product obtained therefrom, which prevent the occurrence of troubles such as breakage of the lance part at low temperatures and at the same time prevent the decrease in connector fitting strength at high temperatures There is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have formulated a polybutylene terephthalate resin composition in which a polyester elastomer having a specific structure is blended and dispersed so as to have a special morphological structure. The present invention was completed by finding out that it was excellent in impact strength and tensile elongation while maintaining the above.

  That is, the gist of the present invention is that polyester-ether type thermoplastic elastomer (B) 1 to 30 weights comprising an aromatic polyester block and an aliphatic polyether block with respect to 100 parts by weight of polybutylene terephthalate resin (A). In the polybutylene terephthalate resin composition containing a part, the aliphatic polyether block comprises a polyalkylene ether glycol having a weight average molecular weight of 400 to 6000 as a constituent unit and occupies 25 to 80% by weight of (B). The observation result of the resin composition by a transmission electron microscope shows a so-called sea-island structure in which (A) is the sea and (B) is the island, and the average diameter of the island portion containing the polyalkylene ether glycol component is It exists in the resin composition characterized by being 0.05-0.30 micrometer.

  According to the present invention, a polybutylene terephthalate resin composition excellent in impact strength and tensile elongation can be obtained while maintaining a high elastic modulus, and can be applied to various parts such as automobiles, OA equipment, and precision machines. . In particular, the connector with a lance shape obtained by the resin composition of the present invention can improve the quality by reducing the trouble of breakage of the lance at low temperature and at the same time maintaining the fitting strength of the connector at high temperature. Can be planned. Accordingly, the resin composition of the present invention can be preferably applied to the use of automobile parts, and is further suitable for the use of connectors.

Hereinafter, the present invention will be described in detail.

(A) Polybutylene terephthalate resin (A) Polybutylene terephthalate resin (PBT resin) used in the present invention is a polyester resin mainly composed of terephthalic acid and 1,4-butanediol, and terephthalic acid is all dicarboxylic acid. The polyester resin occupies 50 mol% or more of the acid component and 1,4-butanediol occupies 50 wt% or more of the total diol component. Among these, terephthalic acid preferably occupies 80 mol% or more of the total dicarboxylic acid component, and more preferably 95 mol% or more. 1,4-butanediol preferably accounts for 80 mol% or more of the total diol component, and more preferably 95 mol% or more.

  From the viewpoint of hydrolysis resistance of the resin composition of the present invention, the terminal carboxyl group amount of (A) PBT resin is preferably 30 eq / ton or less, more preferably 25 eq / ton or less, and particularly preferably. Is 20 eq / ton or less. The amount of terminal carboxyl groups can be determined by dissolving PBT resin in an organic solvent and titrating with an alkali hydroxide solution. By setting the terminal carboxyl group amount of the PBT resin to 30 eq / ton or less, the reason is not clear, but due to the synergistic effect of blending the polyester ether type thermoplastic elastomer (B) described later, the bending characteristics at low temperature Can be improved. Moreover, hydrolysis resistance can be remarkably improved, and molding residence stability and heat aging stability can be improved.

  Since the carboxyl group in the PBT resin acts as an autocatalyst for hydrolysis, if there is a terminal carboxyl group in an amount exceeding 30 eq / ton, hydrolysis starts early, and hydrolysis proceeds in a chain, The degree of polymerization of the PBT resin decreases rapidly. In the resin composition of the present invention, by using a PBT resin having a terminal carboxyl group amount of 30 eq / ton or less, the progress of early hydrolysis and oxidative deterioration is suppressed even under high temperature and high humidity conditions, It can be preferably applied to automotive parts such as connectors.

  In the present invention, (A) the intrinsic viscosity η (A) of the PBT resin is measured at a temperature of 30 ° C. using a mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1/1 (weight ratio). It is usually 0.50 to 3.0 dl / g, preferably 0.6 to 2.0 dl / g, and more preferably 0.7 to 1.5 dl / g. If the intrinsic viscosity is smaller than the lower limit value, the mechanical strength tends to decrease. If the intrinsic viscosity is larger than the upper limit value, the melt viscosity of the resin composition increases, the fluidity decreases, and the moldability tends to decrease. . Two or more types of PBT resins may be used in combination, and in that case, the intrinsic viscosity of the combined PBT resin as a whole is preferably within the above-described range.

(B) Polyester / ether type thermoplastic elastomer The polyester / ester type thermoplastic elastomer as the component (B) used in the present invention has an aromatic polyester block (b-1) as a hard segment and an aliphatic as a soft segment. A polyester-ether type block copolymer composed of a polyether block (b-2), wherein the aliphatic polyether block (b-2) is mainly composed of a polyalkylene ether glycol.

(B-1) Aromatic polyester block As the dicarboxylic acid component constituting the aromatic polyester block (b-1) in the present invention, phthalic acid, terephthalic acid, isophthalic acid, 1,4- or 2,6-naphthalenedicarbon Examples include aromatic dicarboxylic acids such as acids, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenylether dicarboxylic acid, 4,4′-diphenylsulfonedicarboxylic acid, and diol components include ethylene glycol and propylene glycol. Aliphatic diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol; 4,4′-dihydroxybiphenyl, 2,2 -Bis (4′-β-hydroxyeth And aromatic diols such as xylphenyl) propane. Each of these components may contain one kind or two or more kinds, and may have a substituent such as halogen.

  Among these, a block composed of terephthalic acid and tetramethylene glycol is preferable from the viewpoints of compatibility and heat resistance. Among these, terephthalic acid is mainly composed of terephthalic acid and tetramethylene glycol. Specifically, terephthalic acid in the dicarboxylic acid component is preferably 50 mol% or more, more preferably 70 mol% or more, and tetramethylene in the diol component. It is preferable that glycol is 50 mol% or more, more preferably 70 mol% or more.

(B-2) Aliphatic polyether block Examples of the polyalkylene ether glycol that is the main component of the aliphatic polyether block (b-2) include polyethylene glycol, polypropylene glycol, polytrimethylene ether glycol, and polytetramethylene ether. Polyalkylene having 1 to 8 carbon atoms, preferably 2 to 6 carbon atoms, such as glycol, polyhexamethylene ether glycol, block or random copolymer of ethylene oxide and propylene oxide, block or random copolymer of ethylene oxide and tetrahydrofuran Examples include ether glycol, and among them, polytetramethylene ether glycol is preferable. Here, the polyalkylene ether glycol is the main component of the aliphatic polyether block (b-2) means that the polyalkylene ether glycol is 50 mol% or more in the aliphatic polyether block (b-2). Further, it means 70 mol% or more, particularly 90 mol% or more.

  The weight average molecular weight of the polyalkylene ether glycol is preferably 400 to 6,000, more preferably 500 to 4,000, and particularly preferably 600 to 3,000. When the molecular weight is less than the lower limit, If the expression of properties is lowered and the upper limit is exceeded, the miscibility with polybutylene terephthalate is lowered, which is not preferable. (B) Content of the polyalkylene ether glycol structural unit in the whole thermoplastic elastomer which is a component is 25 to 80 weight%, Preferably it is 30 to 70 weight%, More preferably, it is 40 to 60 weight%. When this content is less than 25% by weight, the bending characteristics at low temperatures of the PBT resin composition are lowered, and the hydrolysis resistance is also lowered. On the other hand, when it exceeds 80% by weight, the affinity with the PBT resin is lowered, and the mechanical properties are lowered. Furthermore, the content of the polyalkylene ether glycol structural unit in the whole PBT resin composition of the present invention is usually 0.1 to 30% by weight, preferably 0.5 to 20% by weight, more preferably 0.8. -10% by weight. If it is less than 0.1% by weight, the impact strength and the tensile elongation are insufficient, and if it exceeds 30% by weight, the elastic modulus is lowered.

  (B) A polyester / ether type thermoplastic elastomer produces a polyester oligomer from a dicarboxylic acid or an ester-forming derivative thereof and a low molecular weight glycol or an ester-forming derivative thereof, and a polyalkylene ether having a predetermined molecular weight is formed on the polyester oligomer. It can be produced by mixing a predetermined amount of glycol and copolymerizing with a tin catalyst or the like.

Polybutylene terephthalate resin composition In the composition of the present invention, the blending amount of the (B) polyester / ether type thermoplastic elastomer is 1 to 30 parts by weight with respect to 100 parts by weight of the (A) PBT resin. The amount is 1.5 to 20 parts by weight, and particularly preferably 2 to 10 parts by weight. When the blending amount of the component (B) is less than 1 part by weight, the mechanical strength such as impact strength and the effect of improving bending strain at low temperature are small, and the effect of preventing breakage at a low temperature of the lance is reduced. If it exceeds the weight part, the elastic modulus is lowered, so that the connector fitting strength at high temperature is lowered.

  The intrinsic viscosity η (B) of the (B) polyester ether type thermoplastic elastomer used in the present invention is a mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1/1 (weight ratio). When measured at a temperature of 30 ° C., it is usually 0.50 to 3.0 dl / g, preferably 0.6 to 2.5 dl / g, more preferably 0.7 to 2.0 dl / g. It is. Even if the intrinsic viscosity is smaller than the lower limit value or larger than the upper limit value, the miscibility with the PBT resin is lowered in any case, and the mechanical properties are not exhibited.

  In the present invention, the ratio [η (A) / η (B)] of the (A) polybutylene terephthalate resin to the intrinsic viscosity of the (B) polyester / ether type thermoplastic elastomer is usually 0.3. -3.0, more preferably 0.5-2.0, and particularly preferably 0.7-1.5. Even if the ratio [η (A) / η (B)] of these intrinsic viscosities is smaller than the lower limit value or larger than the upper limit value, the miscibility with polybutylene terephthalate decreases, and the mechanical strength (tensile strength, bending There is a tendency for the strength and bending strain to decrease.

  In order to achieve the object of the present invention, a resin composition comprising the components (A) and (B) forms a sea-island structure, (A) forms a sea, and (B) forms an island structure. It is necessary that the average diameter of the island portion containing the polyalkylene ether glycol component is within a predetermined range by observation with a microscope. There are various means for taking such a morphological structure, and a typical example using a twin screw extruder will be described later.

  The average diameter of the island portion containing the polyalkylene ether glycol component is measured using a transmission electron microscope and appropriate image processing software as described in detail in the Examples section below. The diameter is in the range of 0.05-0.30 μm. Furthermore, it is preferable that it is the range of 0.08-0.25 micrometer. When the average diameter is larger than the upper limit value, it is impossible to obtain characteristics excellent in impact strength and tensile elongation while maintaining the high elastic modulus which is the object of the present invention. On the other hand, if the value is smaller than the lower limit, the target of the present invention cannot be achieved. The numerical value of 0.05 μm is also an observation limit as an island part particle in transmission electron microscope observation, and is a numerical value that makes it unclear whether it has a sea-island structure or a uniform structure.

  A twin screw extruder is used for blending the polybutylene terephthalate resin (A) and the polyester ether type thermoplastic elastomer (B). Various types of twin screw extruders can be used as long as they are at least a raw material supply port and a vent hole. The screw may be rotated in the same direction or in a different direction, but the same direction meshing type twin screw extruder is preferred.

  The polybutylene terephthalate resin (A) and the thermoplastic elastomer (B), which are the main raw materials, are supplied from the raw material supply port, and low volatile components such as moisture are removed from the downstream vent holes. In order to improve the dispersion of the elastomer and to keep the average diameter of the island portion within a predetermined range, the screw configuration of the extruder includes at least one, preferably two, a reverse kneading disk or a screw having a reverse screw structure. As described above, it is necessary to improve the dispersion of the polyester-based thermoplastic elastomer by applying one or two or more filled regions of the molten resin and imparting high shear stress by increasing the screw rotation speed.

  As specific extrusion conditions, the set temperature of the barrel and the die is 230 ° C. to 290 ° C., preferably 240 ° C. to 280 ° C. in the case of the polybutylene terephthalate resin composition. The rotation speed of the screw is usually selected from 100 to 700 rpm, and is determined in relation to the screw configuration. However, in order to achieve the object of the present invention, a high-speed rotation speed is preferable, and is selected from a range of 250 to 600 rpm. Further, the extruder may further include a supply port for other components and a vent port that can be decompressed and opened to the atmosphere.

In order to obtain a molded article or a molded article, the polybutylene terephthalate resin composition of the present invention can be blended with a resin additive other than the above, if necessary. Such resin additive is not particularly limited, for example, various stabilizers such as antioxidants such as phosphorus-based and sulfur-based, heat-resistant stabilizers, weather-resistant stabilizers, anti-hydrolysis inhibitors such as epoxy compounds, Lubricants, mold release agents, catalyst deactivators, crystal nucleating agents, crystallization accelerators, UV absorbers, coloring agents such as dyes and pigments, antistatic agents, foaming agents, plasticizers, impact resistance improvers, reinforcing fillers, Well-known resin additives, such as an inorganic filler, a flame retardant, a flame retardant adjuvant, are mentioned.

  If necessary, other thermoplastic resins can be blended. For example, thermoplastic resins such as polyethylene, polypropylene, polystyrene, polyacrylonitrile, polymethacrylic acid ester, ABS resin, polycarbonate, polyamide, polyphenylene sulfide, and thermosetting resins such as phenol resin, melamine resin, silicone resin, and epoxy resin. It is done. These resins may be used in combination of two or more. The supply position of the other resin that can be added to the resin is not particularly limited, and it may be added from the same supply port as the first thermoplastic resin or may be added from another supply port.

  From the above-described polybutylene terephthalate resin composition of the present invention, various types of electrical and electronic parts such as connectors, automobile electrical parts, mechanical fields, medical fields, etc. by ordinary molding methods such as injection molding, extrusion molding, compression molding, hollow molding, etc. A resin molded product can be obtained. A particularly preferable molding method is injection molding or extrusion molding because of good fluidity. In the injection or extrusion molding, it is preferable to control the resin temperature to 230 to 290 ° C, more preferably 240 to 280 ° C, in order to prevent the deterioration of polybutylene terephthalate and achieve the object of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded. In the examples, “part” represents “part by weight”.

[raw materials]
(A) Polybutylene terephthalate resin (PBT resin)
(Mitsubishi Engineering Plastics Co., Ltd., intrinsic viscosity 1.0 dl / g, terminal carboxyl group amount 20 eq / ton)
(B) Thermoplastic elastomer (PTMG copolymer polybutylene terephthalate)
(B1) Polyester / ether type block copolymer having polybutylene terephthalate (hereinafter referred to as PBT) as a hard segment and polytetramethylene ether glycol (hereinafter referred to as PTMG) having a weight average molecular weight of 1000 as a soft segment ( (PTMG content 50% by weight, intrinsic viscosity 1.7 dl / g)
(B2) Polyester-ether type block copolymer having PBT as a hard segment and PTMG having a weight average molecular weight of 2000 as a soft segment (PTMG content 65 wt%, intrinsic viscosity 2.0 dl / g)
(B3) A polyester-ether type block copolymer having PBT as a hard segment and PTMG having a weight average molecular weight of 1000 as a soft segment (PTMG content 10 wt%, intrinsic viscosity 1.15 dl / g)

[Performance evaluation method for molded products]
(1) Tensile test It measured based on ISO527. The units of tensile strength and tensile elongation are MPa and%, respectively. (2) Bending test Measured according to ISO178. The units of strength and elastic modulus are both MPa. (3) Charpy impact test Measured according to ISO179 (with notch processing).

[Measurement of average diameter of island components by transmission electron microscope observation]
[Ultrathin section]
A slice was cut out from the surface perpendicular to the strand direction at the center of the sample pellet. From this section, an ultrathin section having the orthogonal plane as the surface was prepared using an ultramicrotome (Leica, Ultracut UCT) equipped with a sample cooling device (cryo unit) using a diamond knife. The set cutting conditions are a sample chamber temperature of −105 ° C. and a sample thickness of 100 nm.

[staining]
After loading the ultrathin sections on a copper grid, the surface of the sections was exposed to ruthenium tetroxide vapor and stained with ruthenium tetroxide. By this staining, the polybutylene terephthalate is observed as a gray sea, and the component containing the polyalkylene ether glycol is observed as a dark island (see FIG. 2).

[Electron micrograph photography conditions]
The stained ultrathin section was observed with a transmission electron microscope (JEOL 1200EXII type) at an acceleration voltage of 100 kV. The magnification at the time of observation was set to 5000 times, and an image was recorded on a film FG (size: 5.9 × 8.2 cm) made by Fujifilm. The recorded image range is approximately 12 × 16 μm.

[Image processing]
The negative film on which the image was recorded obtained by the TEM observation was digitized with a film scanner (manufactured by Minolta: Image Scan Multi F-3000 type). Digitization was performed at 564 dpi, and a monochrome image file of approximately 1240 × 1800 pixels was obtained.
The obtained monochrome image was obtained by using Photoshop Ver. After adjusting the contrast using 7.0, Media Cybernetics, Inc., Image-Pro Plus Ver. Using 4.5.1, the average diameter of the island portion containing the polyalkylene ether glycol component was measured. The average diameter obtained here is an average value obtained by connecting the two points on the outer periphery of the island portion and measuring the diameter passing through the center of gravity in increments of 2 degrees.
In measurement, the length on the screen was calibrated based on the scale recorded in each image at the time of shooting. The measurement was performed on an island having a diameter of 0.05 μm or more.

[Examples 1-4, Comparative Examples 1-4]
Each component is mixed so that it may become the mixture ratio of Table 1, and it is 250 degreeC by the screw structure shown in FIG. 1 using the twin screw extruder with a barrel diameter of 37 mm (Toshiba machine Co., Ltd. TEM37BS). Each component was melt-kneaded at a screw rotation speed of 200 rpm, which is a normal rotation speed by setting the cylinder temperature, and a high-speed rotation of 400 rpm at which high shear stress is exhibited, and extruded into a strand shape to obtain PBT resin composition pellets. . In FIG. 1, two 28 / 7L are reverse kneading disks, and at a high rotational speed, the molten resin was filled in the region between these two disks and received high shear stress.
From the obtained pellets, using an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. (model SG-75SYCAP-MIII), an ISO test piece was molded under the conditions of a cylinder temperature of 250 ° C. and a mold temperature of 80 ° C., Performance evaluation was performed by the above test method. The results are shown in Table-1.

1) As shown in Comparative Examples 2 and 4, in a polybutylene terephthalate resin composition using a thermoplastic elastomer having a PTMG content of 10% (out of the scope of the present invention), a uniform structure (or island portion is detected) A sea-island structure below the limit) was observed. In such a uniform structure, the tensile elongation is high, but the flexural modulus and impact strength are low, and the object of the present invention for obtaining all three characteristics cannot be achieved.
2) As shown in Comparative Examples 1 and 3, in the polybutylene terephthalate resin composition produced at a screw rotation speed at which high shear stress cannot be exhibited even if the PTMG content is within the range of the present invention, the sea-island structure Was observed. However, the average diameter of the island portion including PTMG is as large as 0.34 to 0.36 μm (out of the scope of the present invention), and the flexural modulus of such a thing is higher than those of Comparative Examples 2 and 4 having the uniform structure described above. However, the tensile elongation and impact strength were low, and the object of the present invention could not be achieved.
3) In a polybutylene terephthalate resin composition produced using a thermoplastic elastomer within the scope of the present invention having a PTMG content of 25 to 80% by weight as in the Examples and produced at a screw rotation speed capable of exhibiting high shear stress. The sea-island structure was observed. Of course, the average diameter of the island portion is also 0.12 to 0.14 μm and is within the scope of the present invention. The bending elastic modulus, tensile elongation, and impact strength of this product were superior to those of the comparative examples having the same compositions (A) and (B), and the object of the present invention was achieved.

[Possibility of industrial use]
According to the present invention, since a polybutylene terephthalate resin composition excellent in impact strength and tensile elongation can be obtained while maintaining a high elastic modulus, it can be applied to various parts such as automobiles, OA equipment, and precision machines. In particular, the connector with a lance shape obtained by the resin composition of the present invention can improve the quality by reducing the trouble of breakage of the lance at low temperature and at the same time maintaining the fitting strength of the connector at high temperature. Can be planned. Accordingly, the resin composition of the present invention can be preferably applied to the use of automobile parts, and is further suitable for the use of connectors.

Screw configuration diagram of the twin screw extruder used in the experiment Electron microscope observation photograph showing the morphology of the pellets of Example 1 Electron microscope observation photograph showing the morphology of the pellet of Comparative Example 1 Electron microscope observation photograph showing the morphology of the pellet of Comparative Example 2

Claims (8)

  Polybutylene terephthalate in which 1 to 30 parts by weight of a polyester / ether type thermoplastic elastomer (B) composed of an aromatic polyester block and an aliphatic polyether block is blended with 100 parts by weight of the polybutylene terephthalate resin (A). In the resin composition, the aliphatic polyether block comprises a polyalkylene ether glycol having a weight average molecular weight of 400 to 6000 as a constituent unit and occupies 25 to 80% by weight of (B). The observation result by an electron microscope shows a so-called sea-island structure in which (A) is the sea and (B) is an island, and the average diameter of the island portion containing the polyalkylene ether glycol component is 0.05 to 0.30 μm. A resin composition characterized by being.   The polybutylene terephthalate resin composition according to claim 1, wherein 1.5 to 20 parts by weight of (B) is blended with respect to 100 parts by weight of (A).   The polybutylene terephthalate resin composition according to claim 1 or 2, wherein the amount of terminal carboxyl groups in (A) is 30 eq / ton or less.   The intrinsic viscosity of (A) (measured at a temperature of 30 ° C. using a mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1/1 (weight ratio): indicated as η (A)) is 0. The polybutylene terephthalate resin composition according to any one of claims 1 to 3, wherein the composition is 50 to 3.0 dl / g.   The intrinsic viscosity of (B) (measured at a temperature of 30 ° C. using a mixed solvent of 1,1,2,2-tetrachloroethane / phenol = 1/1 (weight ratio): indicated as η (B)) is 0. The polybutylene terephthalate resin composition according to any one of claims 1 to 4, wherein the composition is .50 to 3.0 dl / g.   The ratio [η (A) / η (B)] of the intrinsic viscosity of (A) to the intrinsic viscosity of (B) is 0.3 to 3.0. 2. The polybutylene terephthalate resin composition according to item 1.   The blending of (A) and (B) is performed using a twin-screw extruder, and at least one reverse kneading disk or a screw having a reverse screw structure is used as the screw configuration of the extruder. The polybutylene terephthalate resin composition according to any one of claims 1 to 6, wherein at least one full region is formed. The polybutylene terephthalate resin composition according to claim 7, wherein the set temperature of the barrel and the die of the extruder is selected from 230 ° C to 290 ° C, and the rotational speed of the screw is selected from 250 to 600 rpm.

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