JPH09291204A - Polybutylene terephthalate resin composition and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition giving a molded article having excellent surface appearance even by adding a large amount of inorganic filler and exhibiting excellent mechanical strength and moldability by using a modified polybutylene terephthalate resin in combination with a polycarbonate resin. SOLUTION: This resin composition is produced by compounding 100 pts.wt. of a resin component consisting of (A) 95-55wt.% of a modified polybutylene terephthalate resin having 5-40mol% of a comonomer unit (preferably a polybutylene terephthalate copolymer modified with isophthalic acid, etc.) and (B) 5-45wt.% of a polycarbonate resin with (C) 0.001-5 pts.wt. of a crystal nucleation agent (preferably boron nitride), (D) 40-200 pts.wt. of an inorganic filler (preferably a combination of glass fiber and mica) and (E) 0.1-5 pts.wt. of a coloring component (preferably carbon black). The component B is preferably a polymer produced by using bisphenol A as the dihydric phenol of the raw material.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a polybutylene terephthalate resin composition and a molded article obtained by molding the same. More specifically, the present invention not only shows a high transferability to a mold during molding, and the obtained molded product not only has a very good appearance, but is also formed by a tap boss or the like on the back surface of the molded product. The present invention relates to a polybutylene terephthalate resin composition which markedly improves the "sink" on the surface of a product and has excellent mechanical properties and moldability. The resin composition of the present invention is suitably used for exterior parts in the fields of automobiles, architecture, electric / electronic devices and other various industries. Particularly, it is suitably used for automobile interior and exterior parts that require high rigidity and good appearance.

[0002]

2. Description of the Related Art Crystalline thermoplastic polyester resins such as polyalkylene terephthalate resins are excellent in mechanical properties, electrical properties and other physical and chemical properties, and have good processability. Because of its good quality, it is used as an engineering plastic in a wide range of applications such as automobiles and electric / electronic parts. Such crystalline thermoplastic polyester resin is used alone in various molded articles, but depending on the field of use, for the purpose of improving its properties, particularly mechanical properties, various reinforcing agents,
Blending additives has been done. In the field where high mechanical strength and rigidity are required, it is well known to use a fibrous reinforcing agent typified by glass fiber, carbon fiber and the like. However, the crystalline thermoplastic polyester resin containing the fibrous reinforcing agent has high mechanical strength, rigidity, etc., but when added in a large amount, the surface appearance of the obtained molded product has an inorganic filler (reinforcing agent) protruding, Further, flow marks and the like are generated on the surface due to deterioration of fluidity, and it is difficult to obtain a sufficient appearance. In particular, since a highly crystalline polymer such as polybutylene terephthalate has poor transferability to a mold as it is crystallized during molding, it is difficult to obtain a satisfactory appearance. Furthermore, when used for external parts,
There is a tap boss for tightening screw on the back surface of the molded product to fix the molded product, and the mark is generated (sink) on the surface, impairing the external appearance, and it is difficult to obtain a satisfactory external appearance. As a method for solving these problems, a method of adding an amorphous polymer or a fine powder filler such as talc or calcium carbonate to the polybutylene terephthalate resin can be mentioned. On the molding surface, a method of raising the resin temperature to improve the fluidity, or a method of raising the mold temperature to delay the crystallization speed and improve the transferability are generally used. However, when an amorphous polymer is added, it is necessary to add a large amount in order to obtain a sufficient appearance, which causes problems such as deterioration of mechanical properties and peeling on the surface. Further, it is difficult to obtain a sufficiently good appearance by the method of adding a fine powder filler, and a large amount of addition is required to obtain high mechanical strength and rigidity. In addition, there is a limit to the improvement in molding surface, and if the resin temperature is forcibly raised, the resin is thermally decomposed, which causes gas generation and mold contamination. Also, raising the mold temperature increases the molding cycle time, lowers mass productivity, and increases costs. Therefore, development of a material having high mechanical strength and rigidity and a good appearance has been desired.

[0003]

In view of the above-mentioned problems, the present inventors have obtained a polybutylene terephthalate resin molded product having an inorganic filler added thereto and having high strength and rigidity, which is excellent in surface appearance. Therefore, I studied diligently. as a result,
By using a polycarbonate resin in combination with the modified polybutylene terephthalate copolymer, even if a large amount of an inorganic filler is added, the surface of the obtained molded product is hardly noticeable with sink marks, has a very good appearance, and is excellent. Mechanical strength,
They found that they have moldability, and completed the present invention. That is, the present invention provides a modified polybutylene terephthalate resin (A) containing 5 to 40 mol% of comonomer units.
~ 55 wt% and (B) Polycarbonate resin 5-45 wt%
To 100 parts by weight of the resin component consisting of (C) the crystal nucleating agent 0.0
It is a polybutylene terephthalate resin composition prepared by blending 01 to 5 parts by weight, (D) 40 to 200 parts by weight of an inorganic filler, and (E) 0.1 to 5 parts by weight of a coloring component.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the components of the resin material of the present invention will be described in detail. First, (A) a modified polybutylene terephthalate resin containing 5 to 40 mol% of a comonomer unit, which is a base resin of the resin material of the present invention, is terephthalic acid or its ester-forming derivative and alkylene glycol having 4 carbon atoms or its The main component is polybutylene terephthalate obtained by polycondensation of an ester-forming derivative, to which 5-40 mol% (preferably 10
Up to 35 mol%) of another comonomer unit. The third component (comonomer) for constituting the copolymer of (A) is isophthalic acid, naphthalenedicarboxylic acid, diphenylcarboxylic acid, diphenyletherdicarboxylic acid, diphenylethanedicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid, sebacine. Known dicarboxylic acids such as acids and dodecanedioic acid, and alkyl, alkoxy or halogen-substituted products thereof, etc. may be mentioned. Also, these dicarboxylic acid compounds can be used as a copolymer component by being used for polycondensation in the form of a derivative capable of forming an ester, for example, a lower alcohol ester such as dimethyl ester. Examples of the dihydroxy compound used as the third component for forming the copolymer include ethylene glycol, propanediol, diethylene glycol, triethylene glycol, neopentyl glycol, hydroquinone,
Relatively low molecular weight dihydroxy compounds such as resorcinol, dihydroxyphenyl, naphthalenediol, dihydroxydiphenyl ether, cyclohexanediol, 2,2-bis (4-hydroxyphenyl) propane and diethoxylated bisphenol A, and their alkyl, alkoxy or halogen substitution The body etc.

In the present invention, any polybutylene terephthalate copolymer produced by polycondensation with the compound as the third component as described above can be used, but preferably aromatic dicarboxylic acid-modified or alkylene glycol-modified poly A butylene terephthalate copolymer, more preferably an isophthalic acid-modified polybutylene terephthalate copolymer or an ethylene glycol-modified polybutylene terephthalate copolymer is remarkable in the effect of the present invention. Also,
Besides these, trifunctional monomers, namely trimellitic acid,
A polyester having a branched or crosslinked structure in which a small amount of trimesic acid, pyromellitic acid, pentaerythritol, trimethylolpropane or the like is used in combination may be used. The amount of the comonomer unit introduced is 5 to 40 mol%, preferably 10 to 35 mol%, particularly preferably 10 to 25 mol%. When the amount introduced is less than 5 mol%, the crystallinity is high,
The transferability to the mold is poor and it is difficult to obtain a sufficient appearance. When the amount introduced exceeds 40 mol%, the strength and thermal stability are greatly reduced, and sufficient crystallinity and crystallization rate cannot be obtained even if the crystal nucleating agent described later is added, resulting in molding. It causes deterioration of cycle and releasing property, and cannot be practically used.

In order to obtain a good appearance, the heat of fusion and the melting point which are preferable are specifically specified. In the case of a polybutylene terephthalate copolymer, the heat of fusion is 10 to 45 J / g and the melting point is 150 to 220 J. C. and a resin having such characteristics is preferable. Here, the heat of fusion (ΔHm) was measured by using a scanning differential calorimeter (DSC) and holding the sample melted and held at 280 ° C for 1 minute at a rate of 10 ° C / min to 30 ° C,
It is a value calculated from the amount of heat (peak area) when the temperature is raised again at 10 ° C / min and the weight of the measurement sample. Further, in the present invention, for the purpose of improving moldability, particularly mold releasability and shortening the molding cycle, a modified polybutylene terephthalate resin to which a small amount of unmodified polybutylene terephthalate resin is added is used as the component (A). May be. Addition amount of unmodified polybutylene terephthalate resin is 0-15% by weight
Is preferred. If the addition amount is too large, the appearance is deteriorated, which is not preferable. Next, in the present invention, the polycarbonate resin (B) is added as an essential component. This (B) polycarbonate resin is
(A) By being added and blended with the polybutylene terephthalate copolymer, the appearance of the molded article of the composition containing the fibrous filler and / or the non-fibrous inorganic filler is improved.
Especially because it has the effect of suppressing the anisotropy of molding shrinkage,
Since the shrinkage rate of the polycarbonate itself is small, it has the effect of suppressing the shrinkage phenomenon to the surface of the molded product such as the tap boss for tightening on the rear surface of the molded product, and the purpose of having a good appearance in decorative parts with bosses etc. Is an essential component in the present invention. The polycarbonate resin used for such a purpose is a solvent method, that is, a reaction between a dihydric phenol and a carbonate precursor such as phosgene in a solvent such as methylene chloride or the like in the presence of a known acid acceptor and a molecular weight modifier, or a dicarboxylic acid. It can be produced by a transesterification reaction between a polyhydric phenol and a carbonate precursor such as diphenyl carbonate. Here, as the dihydric phenol that can be preferably used, there are bisphenols, particularly 2,2-bis (4-
Hydroxyphenyl) propane, ie bisphenol A
Is preferred. Further, bisphenol A may be obtained by partially or entirely substituting another dihydric phenol. Examples of dihydric phenols other than bisphenol A include hydroquinone, 4,4-dihydroxydiphenyl, bis (4-hydroxyphenyl) alkane, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl) sulfide, bis ( Compounds such as 4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ether or bis (3,5-dibromo-4-hydroxyphenyl) propane, bis (3,5- Halogenated bisphenols such as dichloro-4-hydroxyphenyl) propane can be mentioned. These dihydric phenols may be homopolymers or copolymers of two or more dihydric phenols. Further, the polycarbonate resin used in the present invention may be a thermoplastic random branched polycarbonate obtained by reacting a polyfunctional aromatic compound with a dihydric phenol and / or a carbonate precursor. The polycarbonate used in the present invention is particularly preferably highly fluid.
The addition amount of the polycarbonate (B) is 5 to 45% by weight, preferably 10 to 40% by weight based on the total amount of the components (A) and (B). If the amount is too small, the good appearance (particularly sink mark) of the molded article aimed at by the present invention is inferior, and if it is too large, even if a crystallization agent is added, the molding cycle is increased, the releasability is deteriorated, etc. Is not preferable.

Even if the modified polybutylene terephthalate copolymer is used alone, the appearance is improved to some extent, but the effect is not sufficient, and the strength and the thermal stability are greatly decreased, and the strength of the reinforcing agent is increased. The effect of addition decreases. Also, when the polycarbonate resin is added to the unmodified polybutylene terephthalate resin, the effect of improving the appearance is recognized, but the effect is not sufficient, and when a large amount of the inorganic filler is added, the protrusion of the filler to the surface is not observed. It is difficult to control.

[0008] is an essential constituent of the composition of the present invention (C)
As the crystal nucleating agent, both organic substances and inorganic substances can be used. Inorganic substances include Zn powder, Al powder, simple substances such as graphite, ZnO, MgO, Al ₂ O ₃ , TiO ₂ , and Mn.
Metal oxides such as O ₂ , SiO ₂ and Fe ₃ O ₄ , nitrides such as aluminum nitride, silicon nitride, titanium nitride and boron nitride,
Kaolin and clay can be used alone or in combination of two or more. In addition, as organic substances, calcium oxalate, sodium oxalate, calcium benzoate, calcium phthalate, calcium tartrate, magnesium stearate, organic salts such as polyacrylates, polymers such as polyethylene and polypropylene, and crosslinking of polymers These may be used alone or in combination of two or more.

Boron nitride, kaolin and clay are preferred, and boron nitride is particularly preferred. The amount of the (C) crystal nucleating agent used is 0.001 to 5 parts by weight, preferably 0.002 to 3 parts by weight, more preferably 1002 parts by weight, based on 100 parts by weight of the total of (A) modified polybutylene terephthalate resin and (B) polycarbonate resin. 0.05 to 2 parts by weight. If it is less than 0.001 part by weight, the effect of increasing the crystallization rate is not sufficient.

Next, the inorganic filler (D) used in the present invention is an essential component for obtaining a molded article excellent in performance such as mechanical strength, rigidity and heat resistance, and electrical properties. For this purpose, a fibrous, powdery or plate-like filler is used depending on the purpose, but a fibrous filler is preferably used in order to obtain high mechanical strength and rigidity. Examples of the fibrous filler include glass fibers, asbestos fibers, carbon fibers, silica fibers, silica-alumina fibers, zirconia fibers, potassium titanate fibers, boron nitride fibers, and also metals such as stainless steel, aluminum, titanium, copper and brass. Inorganic fibrous substances such as fibrous substances can be mentioned. Particularly typical fibrous fillers are glass fibers or carbon fibers. In addition, high-melting point organic fibrous substances such as polyamide, fluororesin and acrylic resin can also be used. On the other hand, as the granular filler, silica, quartz powder, glass beads, glass powder, milled glass fiber, calcium silicate, aluminum silicate, talc, diatomaceous earth, silicates such as wollastonite, calcium carbonate, carbonic acid. Examples thereof include carbonates of metals such as magnesium, calcium sulfate, sulfates of metals such as barium sulfate, and various metal powders such as silicon carbide. Further, as the plate-like filler, mica, glass flakes,
Various metal foils and the like can be mentioned. Among these, non-fibrous inorganic fillers include glass flakes, mica powder, talc,
Glass beads and milled glass fibers are preferred. These fillers (D) can be used alone or in combination of two or more. The combined use of fibrous fillers, especially glass fibers, and powdery and / or plate-like fillers is a preferable combination in view of combining mechanical strength, dimensional accuracy, electrical properties and the like. Particularly preferred is the case where glass fiber and mica are added together. The amount of the filler used as the component (D) is 40 to 200 parts by weight per 100 parts by weight of the total of the (A) modified polybutylene terephthalate resin and the (B) polycarbonate resin,
It is preferably 60 to 150 parts by weight. Particularly preferred is a case where 50 to 100 parts by weight of glass fiber and 10 to 50 parts by weight of mica are used together. In particular, when the filler is added in an amount of 70 parts by weight or more, the appearance of the molded article produced by the composition of the present invention is remarkably effective. If the amount is too small, the effect of using the polybutylene terephthalate modified product is difficult to see, and if it is too large, the work by extrusion becomes difficult.

When using these fillers (D), it is desirable to use a sizing agent or a surface treatment agent if necessary. Examples of this are functional compounds such as epoxy compounds, acrylic compounds, isocyanate compounds, silane compounds and titanate compounds. These compounds may be subjected to a surface treatment or a converging treatment in advance, or may be added at the same time when the material is prepared. The amount of the functional surface treatment agent used together is 0 with respect to the filler.
-10% by weight, preferably 0.05-5% by weight.

Further, by further adding (E) a coloring component to the composition of the present invention, the obtained molded article can be a colored molded article which does not require a plating layer or a coating layer. The (E) coloring component used here is not particularly limited in terms of the type of dye or pigment, and any one can be selected from those conventionally used in polybutylene terephthalate compositions. Among them, carbon black is particularly preferable, and azo type, phthalocyanine type, perylene type, quinacridone type, anthraquinone type and the like are preferable. In the present invention, the amount of the coloring component added is 0.1 to 5 per 100 parts by weight of the total of (A) modified polybutylene terephthalate resin and (B) polycarbonate resin.
Parts by weight, preferably 0.3-3 parts by weight, are used. If it is less than 0.1 part by weight, the coloring effect is not sufficiently exerted, and if it exceeds 5 parts by weight, the mechanical strength is lowered and the mold is contaminated at the time of molding.

Further, to the composition of the present invention, a known substance generally added to a thermoplastic resin or the like can be further added and used in order to impart desired properties depending on its purpose.

For example, stabilizers such as antioxidants, ultraviolet absorbers and light stabilizers, antistatic agents, lubricants, release agents, colorants such as dyes and pigments, lubricants and plasticizers may be added. It is possible. In particular, the antioxidant is effective in improving the thermal stability of the composition of the present invention, and specifically, a hindered phenol-based, amine-based, phosphorus-based, thioether-based compound or the like can be used. Among them, it is effective to use one or more of hindered phenol compounds and phosphorus compounds in combination. In particular, the addition of the phosphorus-based stabilizer has a high effect of suppressing the transesterification of the (A) modified polybutylene terephthalate resin and the (B) polycarbonate resin, and the obtained composition exhibits higher thermal stability. The amount of the antioxidant used here is 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, per 100 parts by weight of the total of (A) modified polybutylene terephthalate resin and (B) polycarbonate resin. .

Further, as the resin component, other thermoplastic resins (for example, acrylic resin, fluororesin, polyamide, polyacetal, polysulfone, polyphenylene oxide, etc.) and thermosetting resins (for example, phenol resin) are used as long as the object of the present invention is not impaired. , Melamine resin, polyester resin, silicone resin, epoxy resin, etc., and soft thermoplastic resin (eg ethylene / ethyl acrylate, ethylene / vinyl acetate copolymer, polyester elastomer, etc.) can also be added. You may use together 2 or more types not only 1 type.

The composition of the present invention can be easily prepared by the equipment and method generally used as the conventional resin composition preparation method. For example, after mixing the components, kneading and extruding with a single-screw or twin-screw extruder to prepare pellets, followed by molding, a method of once preparing pellets having different compositions, and mixing the pellets in a predetermined amount. Any method such as a method of subjecting to molding and obtaining a molded article of the desired composition after molding, a method of directly charging one or more of each component into a molding machine, and the like can be used. Also,
Mixing a part of the resin component in the form of fine powder with the other components and adding it is a preferable method for uniformly blending these components. As a molding method for filling the resin into the mold, there are an injection molding method, an extrusion compression molding method and the like, but the injection molding method is general.

[0017]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
The measuring methods for evaluation of physical properties shown in the following examples are as follows. Tensile strength Measured according to ASTM D-638 (test specimen ASTM type: thickness 3 mm). Bending Strength / Elastic Modulus Bending elastic modulus was measured according to ASTM D-790. The appearance and moldability were measured by the following methods. (1) Surface gloss Test piece molded under the following conditions (70mm x 40mm x 3mm thickness)
45 degree with a digital variable angle gloss meter (UGV-40 manufactured by Suga Test Instruments Co., Ltd.) in accordance with JIS K7105 gloss measurement.
The gloss at 45 degree reflection was measured. Molding machine Toshiba Corporation IS80 molding conditions Nozzle C1 C2 C3 Cylinder temperature (℃) 260 250 240 220 Injection pressure 750 kg / cm ² Injection speed 2.0 m / min Mold temperature 90 ℃ (2) Surface appearance Surface appearance-1 The surface condition of the molded test piece was visually observed and the following points were given. 1; There is no filler floating or flow mark on the surface, showing a uniform surface. 2; No filler floating on the surface, but a flow mark is seen. 3; Some floating filler is seen on the surface. 4; Floating of the filler is strongly seen on the surface and flow marks are also seen. Surface appearance-2 Under the following molding conditions, a test piece of the shape shown in Fig. 1 (thickness 4 mm
t) was molded, the sink mark level was visually observed, and the sink mark state was evaluated by a contour shape measuring instrument (SE-3C manufactured by Kosaka Laboratory), and the following points were given. 1; sink mark is not seen on the surface, sink mark level is 5 μm
Below 2; some sink marks are seen on the surface, sink level is 5-10 μm
3; sink mark is seen on the surface, sink mark is 10 to 20 μm 4; large sink mark is seen on the surface, sink mark is 20 μm or more Molding machine Sumitomo Heavy Industries, Ltd. SG-150U molding Conditions Nozzle C1 C2 C3 Cylinder temperature (° C) 265 265 265 250 Injection pressure 800 kg / cm ² Injection speed 1.2 m / min Mold temperature 90 ° C (3) Moldability For the test pieces prepared under the above molding conditions, I gave the following points. 1; Good mold release property, one molding cycle is 30 seconds or less 2; Good mold release property, one molding cycle is 30 seconds to 50 seconds Within 3; one molding cycle takes 50 seconds or more, and mold releasability from the mold is somewhat inferior 4; Mold releasability from the mold is poor, and mold release failure occurs at least once in 10 times Example 1 (A) Polybutylene terephthalate copolymer (ΔHm = 43 J / g, Tm = 205 ° C.) modified by copolymerizing 12.5 mol% of dimethyl isophthalate (A-1) to 85% by weight (B ) Addition of 15% by weight of polycarbonate resin, 0.5 parts by weight of boron nitride (C-1) per 100 parts by weight of (A) + (B),
100 parts by weight of glass fiber (D-1), carbon black (E-
1) 1 part by weight was added and various evaluations were carried out.

Example 2 Evaluation was carried out in the same manner as in Example 1 except that the amount of the (B) polycarbonate resin in Example 1 was 30% by weight (70% by weight of (A)). Example 3 80 parts by weight of (D) glass fiber (D-1) and mica of Example 1 above
(D-2) The same procedure as in Example 1 was carried out except that 20 parts by weight were added together. Comparative Examples 1 to 3 In contrast to Example 1, the case where only the modified polybutylene terephthalate copolymer (A-1) is used is Comparative Example 1, the case where the crystal nucleating agent component is not added is Comparative Example 2, and The case where the modified polybutylene terephthalate resin (A-0) and the polycarbonate resin were used was Comparative Example 3, and the other additives and the addition amounts were the same as in Example 1. Comparative Examples 4 to 5 Example 2 is different from Example 2 except that the (C) crystal nucleating agent is not added to Comparative Example 4 and the case where unmodified polybutylene terephthalate is used is Comparative Example 5. Tested and evaluated in the same manner as in. Comparative Example 6 In contrast to Example 3, a case where an unmodified polybutylene terephthalate resin is used is shown in Comparative Example 6. Examples 5 to 6 Tests and evaluations were performed in the same manner as in Example 1 except that the addition amount of each component of Example 1 was changed. Examples 7 to 8 As shown in Table 1, the modified polybutylene terephthalate copolymers described below were used and tested and evaluated in the same manner as in Example 1. Examples 9 to 13 As shown in Table 2, the same tests and evaluations as in Example 1 were carried out except that the crystal nucleating agent (C), the inorganic filler (D) and the coloring component (E) were changed. Example 14 70% by weight of a polybutylene terephthalate component obtained by adding 10% by weight of an unmodified polybutylene terephthalate resin (A-0) to 60% by weight of the modified polybutylene terephthalate copolymer (A-1) of Example 1 %, 30% of (B) polycarbonate resin
0.5% by weight of boron nitride (C-1) per 100 parts by weight of (A) [(A-1) + (A-0)] + (B), glass fiber (D-1) 100 parts by weight of carbon black (E-1)
Parts by weight were added and various evaluations were carried out.

Comparative Examples 7 to 11 In contrast to Example 3, Comparative Example 7 shows the case where (B) the polycarbonate resin is not added. Further, in contrast to Example 4, the case where an unmodified polybutylene terephthalate resin is used is Comparative Example 8, the case where (B) polycarbonate resin is not added is Comparative Example 9, and Example 7 is compared with Example 6. 8 against (C)
Comparative examples 10 and 11 show the cases where the crystal nucleating agent was not added. Comparative Examples 12 to 16 Comparative Examples 12 to 16 show a case where an unmodified polybutylene terephthalate resin was used or a polycarbonate was not added to Examples 9 to 13. Comparative Example 17 In Example 14, 70% by weight of polybutylene terephthalate component obtained by adding 30% by weight of unmodified polybutylene terephthalate resin (A-0) to 40% by weight of modified polybutylene terephthalate copolymer (A-1). Various evaluations were carried out in the same manner except that they were used. The evaluation results are shown in Tables 1 to 4.

The modified polybutylene terephthalate copolymers used in Examples and Comparative Examples are as shown below. Types of polybutylene terephthalate copolymer (A-2) Polybutylene terephthalate copolymer modified by copolymerizing 30 mol% of dimethyl isophthalate (ΔHm = 32J / g, Tm = 171 ° C) (A-3) Polybutylene terephthalate copolymer modified by copolymerizing 17.5 mol% of ethylene glycol (ΔHm = 35J / g, Tm = 205 ° C)

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

[0025]

As described above, the polybutylene terephthalate resin composition of the present invention is prepared by blending a copolymerized polybutylene terephthalate having a specific composition with a polycarbonate resin and further adding a specific crystal nucleating agent and an inorganic filler. It has high mechanical strength and rigidity, has good moldability, has a high effect of improving sink marks, and shows a very excellent appearance of a molded product. The molded product obtained from this composition is applied to exterior parts such as automobiles, electric machines and building materials, which are particularly required to have high strength and good appearance.

[Brief description of drawings]

FIG. 1 is a diagram showing a shape of a test piece used for evaluation of surface appearance in Examples, (a) is a top view and (b) is a side view.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08K 3/38 KJS C08K 3/38 KJS 7/06 7/06 7/14 KKF 7/14 KKF // B60R 1 / 06 7626-3D B60R 1/06 Z B60S 1/38 B60S 1/38 Z (C08L 67/02 69:00)

Claims (11)

[Claims] 1. A modified polybutylene terephthalate resin containing (A) 5 to 40 mol% of a comonomer unit (95 to 55% by weight) and (B) a polycarbonate resin (5 to 45% by weight) based on 100 parts by weight of a resin component. , (C) crystal nucleating agent 0.001 to 5 parts by weight, (D) inorganic filler 40 to 200 parts by weight and (E) coloring component 0.1 to
A polybutylene terephthalate resin composition containing 5 parts by weight. 2. The polybutylene terephthalate resin composition according to claim 1, wherein the heat of fusion of the modified polybutylene terephthalate resin (A) is 10 to 45 J / g. 3. The polybutylene terephthalate resin composition according to claim 1, wherein the comonomer unit of the modified polybutylene terephthalate resin (A) is an isophthalic acid residue and / or an alkylene glycol residue. 4. The component (A) contains 0 to 15% by weight of an unmodified polybutylene terephthalate resin.
The polybutylene terephthalate resin composition according to any one of 1. 5. The polybutylene terephthalate resin composition according to claim 1, wherein the crystal nucleating agent (C) is one or more selected from boron nitride, kaolin and clay. 6. The polybutylene terephthalate resin composition according to claim 1, wherein the amount of the inorganic filler (D) is 60 to 150 parts by weight. 7. The inorganic filler (D) is one kind or two or more kinds selected from glass fiber, carbon fiber, glass beads, glass flake, talc and mica. Polybutylene terephthalate resin composition. 8. The polybutylene terephthalate resin composition according to claim 1, wherein glass fiber and mica are used together as the inorganic filler (D). 9. (D) 50 to 100 glass fibers as an inorganic filler
The polybutylene terephthalate resin composition according to claim 8, wherein 10 parts by weight and 10 to 50 parts by weight of mica are used in combination. 10. The polybutylene terephthalate resin composition according to claim 1, wherein (E) the coloring component is carbon black or a coloring dye / pigment. 11. An automobile decorative component selected from a stay for a door mirror or an inner mirror, an outer handle and a wiper component, which is obtained by molding the polybutylene terephthalate resin composition according to any one of claims 1 to 10. Molding.