JPH0684467B2 - Polyester resin composition with excellent impact strength - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a glass fiber reinforced polyester resin composition having improved physical properties, particularly improved impact strength and moldability such as injection molding. Regarding

[Conventional technology]

Polyethylene terephthalate (hereinafter sometimes abbreviated as PET) or poly (1,4-butylene terephthalate) (hereinafter P
(Sometimes abbreviated as BT) has excellent heat resistance, chemical resistance, mechanical properties, electrical properties, etc. and is used in many industrial products such as fibers and films. In particular, PET reinforced with an inorganic filler such as glass fiber has been remarkably improved in thermal properties and mechanical properties, and thus has been widely used in applications such as engineering plastics in recent years.

However, PET reinforced with such a filler does not always have sufficient impact resistance of the molded product, and the molded product is destroyed when secondary processing of this molded product, transportation of the molded product, and use of the molded product. The problem often arises.

Various methods are known as means for improving the impact resistance of the filler-reinforced polyester resin, but it is common to add an elastic polymer to the filler-reinforced PET or the filler-reinforced PET.

For example, JP-B-45-26223 discloses a copolymer of vinyl ester of saturated aliphatic monocarboxylic acid and α-olefin as an impact modifier for polyester resin. JP-B-45-26224 discloses a copolymer of an acrylic ester and a conjugated diene as an impact modifier for polyester resin. Japanese Examined Patent Publication (Kokoku) No. 45-26225 discloses an ionomer as an impact modifier for polyester resin. However, it cannot be said that the desired impact strength of the molded product obtained by the above method is sufficiently improved.

Various other methods are known for modifying the impact strength of filler-reinforced polyester resins. For example, JP-A-51-1
44452, JP 52-32045, JP 53-117049
Japanese Patent Laid-Open Publication No. 2003-242242 discloses a method of blending a polyester resin with a copolymer of α-olefin and α, β-unsaturated carboxylic acid glycidyl ester. In addition to this copolymer, a method of additionally using an ethylene copolymer as a third component is disclosed in JP-A-58-17148 and 58-58.
-17151, a method of using polyphenylene sulfide in combination is disclosed in JP-A-57-92044.

It cannot be said that sufficient impact strength was obtained even by these methods.

Impact strength can be improved by blending an extremely large amount of elastic material with a filler-reinforced polyester resin (see, for example, Japanese Patent Publication No. 59-3).
No. 0742). However, blending a large amount of elastic material reduces the heat resistance and mechanical strength inherent in polyester.

It is known from JP-A-53-102360 to increase warpage resistance by incorporating PBT into a PET-based filler-reinforced polyester. However, the impact strength cannot be expected to increase even if PBT is added to the PET-based filler-reinforced polyester.

Further, the present inventors previously used a combination of a predetermined amount of PET-based polyester in the PET-based polyester blended with the reinforcing filler in JP-A-61-246251, further, a metal salt of a polymer having a specific carboxyl group By reforming with a predetermined amount,
It was shown that the impact resistance of the molded product was extremely high, and in some cases, the notched Izod impact strength could exceed 20 kg · cm / cm. However, since the composition is obtained by kneading PET-based polyester and PBT-based polyester under high temperature, an S-exchange reaction occurs, the heat resistance of the obtained molded product is insufficient, and scraps of the molded product are crushed. When the raw material is mixed with the unformed raw material and the raw material is collected, high impact strength cannot be obtained when the unformed raw material is used for molding.

The above-mentioned conventional glass fiber reinforced polyethylene terephthalate resin composition shows a decrease in impact strength when exposed to high temperature for a long time, and the surface gloss and the release rate are improved unless the temperature of the mold during molding is relatively high. There is a problem that a molded product with good moldability cannot be obtained.

[Problems to be solved by the invention]

The first object of the present invention is to improve the impact strength of the conventional glass fiber reinforced polyethylene terephthalate while maintaining the excellent physical properties of the glass fiber, and to suppress the decrease of impact resistance when exposed to high temperature for a long time. To provide a reinforced polyethylene terephthalate resin composition. A second object of the present invention is to provide a glass fiber reinforced polyethylene terephthalate resin composition which gives a molded article excellent in surface gloss and releasability even at a low mold temperature.

[Means for solving problems]

As a result of intensive studies to achieve the above object, the present inventors have modified a copolyester having a specific composition with a metal salt of a copolymer of α-olefin and α, β-unsaturated carboxylic acid. As a result, the impact strength of the molded product becomes extremely high, and even if these molded products are crushed into granules and mixed with the unmolded raw material to mold, it is almost the same as when molding only the unmolded raw material. It shows the same high impact strength, and surprisingly, it maintains high impact strength even after being exposed to a high temperature of 150 ° C for a long time, and as a PET resin composition, it has a surface gloss even at a relatively low mold temperature. In addition, it is possible to obtain an injection-molded article having good mold releasability, and further, in the composition of the present invention, the original properties (for example, heat resistance and mechanical strength) of the glass fiber reinforced polyethylene terephthalate resin composition are sufficient. It found that it is held thereby achieving the present invention.

That is, the present invention is (A) a copolyester substantially composed of structural units represented by the following (I) to (IV): _{(III) OCH 2 -CH 2 -O} (IV) OCH 2 CH 2 CH 2 CH 2 over O _n (where, R represents a divalent group obtained by removing a carboxyl group from an aliphatic dicarboxylic acid or 9 carbon atoms And n is an integer of 8 to 84.) (I) is bound to (III) and / or (IV), (II) is bound to (III) and / or (IV) And substantially the total number of moles of (I) and (II) is (III)
Is equal to the total number of moles of (IV) and (II) is 0.2 to 10 moles per 100 moles of (I) in the copolyester, and (IV) is CH ₂ CH ₂ CH ₂ CH ₂ O. Repeating unit is 1
Copolyester included in the proportion of ~ 20 mol, 100
Parts by weight (B) α-olefin and α, β-unsaturated carboxylic acid optionally and a metal salt of a copolymer of a third vinyl monomer, 3
˜100 parts by weight (C) A glass fiber, a polyester resin composition having an excellent impact resistance of 5 to 60% by weight based on the total composition.

Copolyester (A) used in the present invention
Is a copolyester having dramatically improved brittleness, which is one of the major drawbacks of polyethylene terephthalate. The composition of the present invention has high impact resistance. It is based on containing.

The unit represented by (I) in the copolyester (A) is a unit derived from terephthalic acid or its ester-forming derivative, such as dimethyl terephthalate or diethyl terephthalate. The unit (I) may be replaced with a small amount of a unit based on a dicarboxylic acid component other than terephthalic acid or an ester-forming derivative thereof within a range that does not impair the effects of the present invention.

The unit represented by (II) is a unit derived from an aliphatic dicarboxylic acid having 9 or more carbon atoms or an ester-forming derivative thereof. Regarding the carbon number of the aliphatic dicarboxylic acid, the carbon number of the main chain between the carboxyl groups of the dicarboxylic acid is preferably 7 or more (excluding the carbon atoms of the carboxyl group), and the main chain optionally has branching. Or a part of them may form a ring. The number of carbon atoms between carboxyl groups in the aliphatic dicarboxylic acid forming a ring is the smallest. Examples of such an aliphatic dicarboxylic acid having 9 or more carbon atoms include azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, octadecadicarboxylic acid, eicosandicarboxylic acid, dimer acid. , Dimer acid hydrogenated products, and ester-forming derivatives thereof. The aliphatic dicarboxylic acids or their ester-forming derivatives may be used alone or in admixture of two or more.
Particularly preferred dicarboxylic acids in the present invention are dimer acids and hydrogenated dimer acids.

The dimer acid in the present invention is produced from an unsaturated fatty acid containing 18 carbon atoms such as linoleic acid and linolenic acid, or a monohydric alcohol ester thereof, and is mainly composed of dimer acid having 36 carbon atoms. However, some basic acids and trimer acids are also included. In order to achieve the object of the present invention, it is preferable to use dimer acid having a low content of basic acid and trimer acid.

The unit of (II) is 0.2 mol or more per 100 mol of the unit of (I).
10 mol or less, preferably 5 mol or less, more preferably 3 mol
It is preferably contained at a ratio of not more than mol. Within this range, the crystallized product of the copolyester exhibits excellent ductility while maintaining high rigidity, and as a result, high impact strength is imparted to the composition of the present invention. If the proportion is less than 0.2 mol, improvement in toughness cannot be sufficiently achieved as in the case of using polytetramethylene glycol alone as a copolymerization component. On the other hand, if the amount exceeds 10 moles, the melting point of the crystallized product is greatly lowered, and the rigidity is impaired, which is not suitable for the purpose of the present invention.

Further, in the present invention, when modified with the above-mentioned proportion of the unit (II), the brittleness of the crystallized polyethylene terephthalate, which is slightly improved by modification with only poly (tetramethylene oxide) glycol, is dramatically improved.
This effect is not achieved with aliphatic dicarboxylic acids having less than 9 carbon atoms. The upper limit of the carbon number of the aliphatic dicarboxylic acid is not particularly limited, but 100 or less is preferably used in terms of practical use. The range of carbon number of the aliphatic dicarboxylic acid more preferably used is 16 to 54.

The unit represented by (III) is a unit derived from ethylene glycol.

The unit represented by (IV) is a unit derived from poly (tetramethylene oxide) glycol. The use of poly (tetramethylene oxide) glycol as a copolymerization component is necessary to improve the brittleness of a substantially non-oriented crystallized product of polyethylene terephthalate, and the poly (tetramethylene oxide) glycol is used as a copolymerization component. Repeating unit in (tetramethylene oxide) glycol
CH ₂ CH ₂ CH ₂ CH ₂ —O is 1 mol or more and 20 mol or less, preferably 3 mol or more and 15 mol or less, and more preferably 3 mol or more.
It is preferably contained in a proportion of 10 mol or less. If the proportion of copolymerization is low, the brittleness of polyethylene terephthalate cannot be improved, and as the proportion of copolymerization increases, the rigidity of the crystallized product decreases, and the melting point also decreases, which is contrary to the object of the present invention. Will be things.

The molecular weight of poly (tetramethylene oxide) glycol needs to be about 600 to 6000 (degree of polymerization (n): 8 to 84). Use of poly (tetramethylene oxide) glycol having a molecular weight outside the above range is not preferable because ductility is reduced. A more preferred molecular weight range is about 600
-2000 (degree of polymerization (n): 8-28).

When obtaining the copolyester (A) used in the present invention, a small amount of, for example, glycerin, trimethylolpropane, pentaerythritol, hexanetriol 1,2,6, trimethylolethane is obtained within a range that does not impair the effects of the present invention. Such as triol or tetraol, benzenetricarboxylic acid typified by trimellitic acid, trimesic acid, and pyromellitic acid, or benzenetetracarboxylic acid, or a polyvalent compound having 3 to 4 hydroxyl groups and carboxyl groups bonded to each other. Use in combination with monofunctional monomers such as polyfunctional monomers such as hydroxycarboxylic acid and aliphatic monocarboxylic acids such as stearic acid and oleic acid, benzoic acid, phenylacetic acid, diphenylacetic acid and β-naphthoic acid. You can also

The copolyester (A) in the present invention is usually produced by a known method used for producing polyester. Generally, a copolyester is produced by heating a mixture of reaction components in the presence or absence of a catalyst under atmospheric pressure or pressure under an inert gas atmosphere. The temperatures employed to carry out these reactions are in the range of 200 ° C to 270 ° C, preferably 230 ° C to 260 ° C.
It is in the range of ° C. After completion of this reaction, the obtained oligomer product is polycondensed. The polycondensation reaction is about 2 at a pressure of 15 mmHg or less, preferably 1 mmHg or less in the presence of a polycondensation catalyst such as a known antimony, titanium, iron, zinc, cobalt, lead, manganese, or germanium catalyst.
It is carried out at a temperature in the range of 70 ° C to 300 ° C.

An aliphatic dicarboxylic acid having 9 or more carbon atoms, poly (tetramethylene oxide) glycol, or an ester-forming derivative thereof can be added before transesterification or during the esterification reaction and during the condensation reaction. It is preferably added after the reaction or the esterification reaction, that is, in the condensation step.

The intrinsic viscosity of the copolyester used in the present invention is preferably about 0.5 or more and about 1.5 or less, more preferably about 0.5 or more and about 0.5 or less when measured in a 50/50 weight mixed solvent system of phenol and tetrachloroethane at 30 ° C.
It is in the range of 1.0 or less.

In the present invention, a metal salt (B) of a copolymer of α-olefin and α, β-unsaturated carboxylic acid and optionally a third vinyl monomer (hereinafter sometimes referred to as an ionic copolymer) is used. Added to copolyester. The α-olefin which constitutes the ionic copolymer is ethylene, propylene, etc., and the α, β-unsaturated carboxylic acid is acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, etc. Examples of the vinyl monomer include ethyl acrylate and vinyl acetate, and examples of the metal include monovalent to trivalent metals, but sodium, potassium, calcium, zinc aluminum and the like are preferable.

It was found that when an alkali metal such as sodium or potassium is selected as the metal, not only extremely high impact strength is obtained, but also the impact strength does not decrease even after long-term holding at high temperature. According to the research conducted by the present inventors, such a peculiar phenomenon was recognized only when a very special polyester (A) was selected.

It was also found that when zinc was selected as the metal, a resin composition with little coloring was obtained, and the coloring of the composition was little even after holding for a long time at high temperature.

These ionic copolymers include α-olefin and α, β-
It can be prepared by copolymerizing an unsaturated carboxylic acid and optionally a third vinyl monomer, and then substituting part or all of the carboxylic acid with a metal salt. As another method for producing an ionic copolymer, a copolymer of α-olefin and optionally a third vinyl monomer is graft-weighted with α, β-unsaturated carboxylic acid, and then replaced with a metal salt. There is a way to do it. Yet another production method is to copolymerize α-olefin with α, β-unsaturated carboxylic acid ester and optionally a third vinyl monomer, and then to saponify the carboxylic acid ester moiety and then replace it with a metal salt. There is also a manufacturing method. Although the ionic copolymer obtained by any method is adopted in the present invention, among these ionic copolymers, those particularly preferably used in the present invention are ethylene and acrylic acid or It is a metal salt of a copolymer composed of ethylene and methacrylic acid.

In the above ionic copolymer, it is necessary that the carboxylic acid unit (including the salt form) occupied in the copolymer is 1 mol% or more and 30 mol% or less of all the copolymer units. When it is less than 1 mol%, the impact resistance of the polyester resin is not sufficiently improved. When it is more than 30 mol%,
In the molten state, the ionic copolymer cannot be sufficiently kneaded with the polyester in a short time. A more preferable range of the carboxylic acid unit ratio in the ionic copolymer used in the present invention is 2 mol% or more and 10 mol% or less.

In the present invention, the ionic copolymer does not require that all the carboxyl groups present are neutralized by the metal ions, but at least 20 mol% of all the carboxyl groups may be neutralized by the metal ions. is necessary. If the neutralization rate is less than 20 mol%, the effect of improving the impact resistance of the polyester resin cannot be sufficiently obtained. A preferable neutralization rate is 40 mol% or more, and particularly 60 mol% or more.

The neutralization rate is measured by infrared spectrum analysis of the copolymer. That is, it can be measured by the ratio of the νc = 0 absorption intensity of the carboxyl group formed into a salt and the νc = 0 absorption intensity of the unneutralized carboxyl group.

The blending amount of the component (B) is 3 to 100 parts by weight, preferably 5 to 50 parts by weight, more preferably 20 to 50 parts by weight, based on 100 parts by weight of the copolyester. If the compounding amount is too small, the effect of improving the impact resistance of the molded product will be poor, and if the compounding amount exceeds 100 parts by weight, the mechanical properties of the molded product will deteriorate.

As the glass fiber (C) used in the present invention,
Ordinary glass fiber used for reinforcing plastics may be used, and the diameter is preferably 3 to 30 μm. Depending on the manufacturing method, various forms of roving and chipped strand can be used. Further, the glass fiber is preferably subjected to a treatment such as a silane treatment or a chromium treatment for the purpose of improving the adhesiveness with the plastic. The compounding amount thereof is 5 to 60% by weight, preferably 10 to 50% by weight, based on the whole composition.
When the amount of the glass fiber blended is small, not only sufficient mechanical strength as glass fiber reinforced polyester cannot be obtained, but also impact resistance is not sufficient. On the other hand, if the blending amount exceeds 60% by weight, the fluidity of the system becomes poor and molding becomes difficult. When the content of the glass fiber is 20 to 45% by weight based on the total composition, the composition of the present invention has a high impact strength and a high heat distortion temperature, excellent rigidity, and excellent flowability characteristics, and is extremely well-balanced molding. A resin composition for use is provided.

The above-mentioned copolyester and ionic copolymer,
Usually, it is obtained in the form of powder or particles (pellets, chips). The desired polyester molded article can be produced by simply melt-mixing these and glass fibers, but once the mixture is melt-kneaded to form a pellet or chip and the desired pellet or chip is formed. The molded product can also be melt-molded. Therefore, in the present invention, the mixture of the copolyester, the ionic copolymer, and the glass fiber includes not only those in which the respective powders or particles are simply mixed but also those in which both are melt-kneaded. .

Various additives that are usually added to the polyester when blending the glass fiber and the ionic copolymer with the copolymer polyester or when melt-molding the mixture of the copolymer polyester, the glass fiber and the ionic copolymer. , For example,
A colorant, a release agent, an antioxidant, an ultraviolet stabilizer, a flame retardant and the like may be added. Further, other resins such as polyester resin, polyolefin resin, acrylic resin, polycarbonate resin, polyamide resin, and rubber-like elastic body may be mixed within a range that does not impair the effects of the present invention.

The composition of the present invention can be used to produce various molded articles by not only injection molding but also melt molding methods such as extrusion molding. As the molded product obtained by extrusion molding, it is possible to produce a fiber, rod, film, sheet, plate, tube or pipe having any shape depending on the shape of the molding die. . Further, by cutting such an extrusion-molded product, a melt molding material in the form of chips or particles such as chips, pellets or the like can be obtained. Further, according to the injection molding method, an arbitrary shape can be manufactured depending on the shape of the mold. The molded product obtained by any of the molding methods can be easily further made into a desired final molded product by secondary molding processing such as blow molding, drawing molding or vacuum molding. All of the various molded products obtained have extremely high impact strength.

As described above, the composition of the present invention gives a molded article having an extremely high impact strength which could not be expected with the conventional PET-based polyester resin, and the impact strength is less deteriorated even when exposed to a high temperature for a long time. , The contribution to the world is extremely large.

Furthermore, the composition of the present invention has excellent flow characteristics, and as a PET resin, even when injection-molded in a mold at a relatively low temperature, the polyester is sufficiently crystallized, and the mold release property is good, and the molded product has excellent surface properties. Therefore, it can be said that the resin has excellent moldability.

Applications of the resin composition of the present invention include irons, dryers, heat appliances such as kitchen appliances, coil bobbins, switches,
Electrical / electronic parts such as connectors, gears, mechanical parts such as various covers, under-bonnet parts, automobile parts such as outer plates, etc. may be mentioned.

Hereinafter, the present invention will be described with reference to examples. In the examples, all parts are by weight unless otherwise specified.

Example Reference Example A (Synthesis Example of Copolyester) Using antimony trioxide and phosphorous acid as catalysts, esterification was performed from terephthaleic acid and ethylene glycol at 260 ° C., and then a predetermined amount of aliphatic Dicarboxylic acid and poly (tetramethylene oxide) glycol were added, and polycondensation reaction was carried out under reduced pressure according to a conventional method. The obtained copolymerized polyester was taken out from the nozzle in a strand form by a gear pump, cooled with water, and made into a pellet form by a cutter.

The obtained copolyester was dissolved in hexafluoropropanol and analyzed by 500 MHz ¹ H-NMR for repeating units of aliphatic dicarboxylic acid unit and poly (tetramethylene oxide) glycol based on 100 mol of terephthaleic acid unit (Table. 1).

The obtained copolyester was dissolved in phenol / tetrachloroethane (1: 1 weight ratio) and the intrinsic viscosity was measured (Table 1).

Examples 1 to 11 and Comparative Examples 1 and 2 100 parts of copolymerized polyester (prepared in Reference Example A) thoroughly dried in a hot air dryer in advance and a predetermined amount of ethylene / methacrylic acid as an ionic copolymer. Sodium salt (Trade name: Himilan 1856, manufactured by Mitsui Polychemical Co., Ltd.), and Phos phite168 as an antioxidant
(2 brand name, Ciba-Geigy Co., Ltd.) was mixed with 1/10 weight of the amount of the ionic copolymer used and pre-mixed, then 30 mmφ2
Axial extruder (BT-30-S type manufactured by Plastics Engineering Laboratory Co., Ltd.)
It is put into a hopper and is supplied while being measured with a screen feeder, and a glass fiber bundle of convergent chains with a cut length of 3 mm (manufactured by Nitto Boseki Co., Ltd.) is weighed from a ventro provided in the middle of the cylinder. That is, while supplying, extruding while melt-kneading at a cylinder temperature of 190-270-280-285-285 ° C (from the hopper side), an adapter temperature of 285 ° C, and a die temperature of 275 ° C to obtain strands, which are cut. It was a pellet. Then, the pellets were heated to a cylinder temperature of 265-285-285-285 ° C, a die temperature of 280 ° C, and a mold temperature of 110 ° C.
A test piece having a thickness of 3 mm was molded by an injection molding machine adjusted to ° C. Table 2 shows the Izod impact strength (notched, according to ASTM D256) of the obtained molded product.

Due to the presence of the ionic copolymer in an amount of 5 parts by weight or more,
High impact strength was obtained.

The compositions of the present invention obtained by changing the types, molecular weights and blending amounts of the aliphatic dicarboxylic acid and poly (tetramethylene oxide) glycol of the copolyester all showed high impact strength. In addition, the obtained molded product was
Table 2 shows the results of measuring the Izod impact strength after standing in an air bath at ℃ for 7 days. Despite being exposed to high temperatures for a long time, it maintained high impact strength. Further, the bending strength (according to ASTM D790) of the obtained molded product was measured. The results are shown in Table 2. Each of the compositions of the present invention had excellent flexural strength.

When the blending amount of the ionic copolymer was 1 part by weight, which was outside the range of the present invention, the impact strength of the obtained molded article was insufficient (Comparative Example 1). Further, when the content of the glass fiber was 3% by weight, which was outside the range of the present invention, not only the impact strength of the molded product was not stably exhibited, but also the bending strength was extremely poor (Comparative Example 2). .

Comparative Examples 3 to 7 When no aliphatic dicarboxylic acid was added during the production of the copolyester (Copolyester G, Comparative Example 3),
When poly (tetramethylene oxide) glycol is not added (copolymerized polyester H, comparative example 4) or when an excessive amount is added (copolymerized polyester I, comparative example 5), an aliphatic dicarboxylic acid having a small carbon number is added. In the case of (Copolyester J, Comparative Example 6) and when the aliphatic dicarboxylic acid was used in an excessively large amount (Copolymer Polyester K, Comparative Example 7), the same method as in Reference Example A was used.
The copolyester shown in was obtained.

A molded product was obtained by using the obtained copolyester in the same manner as in Example 3, and the results of measuring Izod impact strength and bending strength are shown in Table 2.

Comparing Example 3 with Comparative Examples 3 to 7, the Comparative Example is inferior in both the impact strength after molding and the impact strength after 7 days at 150 ° C. In particular, it can be seen that the bending strength is considerably low in Comparative Examples 5 to 7.

Comparative Example 8 A molded product was obtained in the same manner as in Example 3 except that polyethylene terephthalate having an intrinsic viscosity of 0.74 dl / g was used in place of the copolyester, and the impact strength of the molded product was measured. The results are shown in Table 2.

In the case of polyethylene terephthalate without any modification, it was not possible to increase the impact strength even if an ionic copolymer was added.

Comparative Example 9 In the same manner as in Example 3 except that an ethylene / ethyl acrylate copolymer (trade name, Yucaron X-190-1, manufactured by Mitsubishi Petrochemical Co., Ltd.) was used instead of the ionic copolymer. A molded product was obtained and the impact strength of the obtained molded product was measured. The results are shown in Table 2.

It was not possible to obtain a high impact strength only by using a polymer which does not form a metal salt.

Examples 12 to 14 and Comparative Examples 10 to 12 Using a zinc salt of ethylene / metallic acid copolymer (trade name: Himilan 1855, manufactured by Mitsui Polychemical Co., Ltd.) as the ionic copolymer, the mold temperature during molding was used. Was molded in the same manner as in Examples 3, 5 and 6 except that the temperature was 130 ° C. to obtain a white, yellowish molded product. Table 3 shows the impact strength of the obtained molded product.

Further, even after the obtained molded product was left in an air bath at 150 ° C. for 7 days, the molded product showed almost no color. When a copolyester having a composition outside the composition range of the present invention is used as the copolyester (Comparative Examples 10 and 11) and when a polyester obtained by copolymerizing an aliphatic dicarboxylic acid having a carbon number of less than 9 is used (comparison Example 12) was inferior to Examples 12 to 14 in impact strength after molding and impact strength and bending strength after standing at 150 ° C. for 7 days.

[Effect of the Invention] The polyester resin composition of the present invention has extremely high impact resistance without significantly lowering the excellent heat distortion temperature of the conventional glass fiber reinforced polyethylene terephthalate resin composition for molding, and It retains high impact strength even when exposed to high temperatures for a long time. Further, it gives a molded product having a good surface gloss and good releasability even at a relatively low mold temperature.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Yokota, 1621 Sakata, Kurashiki, Okayama Prefecture, Kuraray Co., Ltd. (72) Inventor Yoshifumi Murata, 2045, Saezu, Aoyama, Kurashiki, Okayama, Ltd., Kuraray Co., Ltd. (72) ) Inventor Teruhisa Kaneda 2045 Saezu Aoeyama Kurashiki City Okayama Prefecture Kuraray Co., Ltd.

Claims (8)

[Claims] 1. A copolymerized polyester (A) consisting essentially of structural units represented by the following (I) to (IV): _{(III) OCH 2 -CH 2 -O} (IV) OCH 2 CH 2 CH 2 CH 2 -O n ( where, R represents a divalent group obtained by removing a carboxyl group from an aliphatic dicarboxylic acid or 9 carbon atoms And n is an integer of 8 to 84.) (I) is bound to (III) and / or (IV), (II) is bound to (III) and / or (IV) And substantially the total number of moles of (I) and (II) is (III)
Is equal to the total number of moles of (IV) and (II) is 0.2 to 10 moles per 100 moles of (I) in the copolyester, and (IV) is CH ₂ CH ₂ CH ₂ CH ₂ O. Repeating unit is 1
Copolyester contained in a proportion of ~ 20 mol; 100
Parts by weight (B) a metal salt of a copolymer of α-olefin and α, β-unsaturated carboxylic acid and optionally and a third vinyl monomer; 3 to 100 parts by weight (C) glass fiber; based on the total composition A polyester resin composition having an excellent impact strength of 5 to 60% by weight. 2. The polyester according to claim 1, wherein R in the structural unit (II) is a divalent group obtained by removing a carboxyl group from at least one aliphatic dicarboxylic acid having 16 to 54 carbon atoms. Resin composition. 3. In the structural unit (II), R is at least one dicarboxylic acid selected from the group consisting of tetradecanedicarboxylic acid, octadecanedicarboxylic acid, dimer acid and hydrogenated dimer acid except for a carboxyl group. 2
The copolymerized polyester resin composition according to claim 1, which is a valent group. 4. In the structural unit (II), R is a divalent group obtained by removing a carboxyl group from at least one dicarboxylic acid selected from the group consisting of dimer acid and hydrogenated products thereof. The polyester resin composition according to claim 1. 5. In the structural unit (IV), n is 8 or more,
The polyester resin composition according to any one of claims 1 to 4, which is 28 or less. 6. A method according to claim 1, wherein the component (B) is an alkali metal salt of a copolymer of ethylene and acrylic acid or methacrylic acid and optionally a third vinyl monomer.
The polyester resin composition according to item 5. 7. The polyester resin composition according to claim 1 or 6, wherein the metal salt of the component (B) is a sodium salt or a potassium salt. 8. The polyester resin composition according to claim 1, wherein the metal salt of the component (B) is a zinc salt.