JPH05301273A - Polyester resin composition for blow molding and hollow molded article thereof - Google Patents

Abstract

(57) [Summary] [Purpose] Blow molding that has sufficient melt tension and drawdown resistance for blow molding, and that can maintain stable fluidity and can efficiently mold even large hollow moldings. A resin composition for use is provided. [Structure] (A) Thermoplastic polyester resin 1 to 99 whose main repeating unit is a 1,4-butylene terephthalate group
(C) Styrene 40-97 parts by weight per 100 parts by weight of a resin component consisting of 1 part by weight and (B) 99-1 parts by weight of a thermoplastic polyester resin other than (A) whose main repeating unit has a specific ester group. %, Glycidyl ester of α, β-unsaturated acid 60 to 3% by weight, other vinyl monomer 0 to 50% by weight styrene copolymer 0.2 to 10 parts by weight, (D) fibrous, powdery, A blow-molding polyester resin composition obtained by mixing 0 to 100 parts by weight of one or more plate-like fillers and melt-kneading the mixture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition suitable for blow molding, and a hollow molded article molded by the blow molding method using this composition.

[0002]

BACKGROUND OF THE INVENTION Thermoplastic polyester resins are widely used as typical engineering plastics because they have excellent mechanical strength, heat resistance, chemical resistance, electrical properties, etc. in a well-balanced manner. However, most of them were obtained by injection molding. However, in recent years, the use of polyester resins has tended to become more sophisticated and specialized, and it is expected to obtain a hollow molded article by efficiently and economically molding the polyester resin by a blow molding method. For example, pipes, tanks, and the like in an automobile engine room are used in a high temperature atmosphere and are required to have a high degree of mechanical properties. Therefore, in the past, metal products were used exclusively. However, in order to reduce the weight, prevent rust, reduce the processing cost, etc., it is desired to obtain them by blow molding of the thermoplastic polyester resin having the above-mentioned excellent properties. However, since polyester resin is generally the most important property for applying these processing methods, that is, its melt tension is low, drawdown is severe, and it is difficult to obtain a molded product having a desired shape by blow molding. Is. As a method for improving this, a method using a highly polymerized polyester resin having a high intrinsic viscosity, a method using a branched polyester, a method of adding a filler, and the like have been considered. Insufficient material for the law. Also, by blending a polyester resin with a branching agent such as an isocyanate compound or an epoxy compound, or by blending a copolymer of ethylene and α, β-unsaturated glycidyl ester with the polyester resin, the melt tension can be improved. However, the effect is not sufficient, the moldability is unstable, and it is difficult to obtain a uniformly good molded product. The present inventors have found that the melt tension of the polyester resin, a combination with a specific styrene copolymer is effective as a method for improving the drawdown resistance, and as Japanese Patent Application No. 3-275477. Although proposed, such a composition tends to gel slightly depending on conditions,
If sufficient melt tension is obtained, a gelation tendency may occur and stable flowability may be difficult to obtain, and it may be difficult to obtain a hollow molded product having a uniform thickness. There was a problem.

[0003]

Means for Solving the Problems The present inventors have made further improvements, and in particular, have obtained melt tension and drawdown resistance sufficient for blow molding, and have a large hollow molding that maintains stable fluidity. As a result of studying to obtain a blow molding resin composition that can be efficiently molded into a product, this problem is ameliorated by the combined use of two specific types of thermoplastic polyester resins, and stable blow moldability is achieved. It was found that the dimensional accuracy (wall thickness, etc.) was improved, and the present invention was reached. That is, the present invention comprises (A) 1 to 99 parts by weight of a thermoplastic polyester resin whose main repeating unit is a 1,4-butylene terephthalate group, and (B) an ester whose main repeating unit is represented by the following general formula (1): Have a group (A)
Other than 100 parts by weight of resin component consisting of 99 to 1 parts by weight of thermoplastic polyester resin other than

[0004]

[Chemical 2]

(C) Styrene-based copolymer consisting of 40-97% by weight of styrene, 60-3% by weight of glycidyl ester of α, β-unsaturated acid, and 0-50% by weight of other vinyl-based monomer 0.2
To 10 parts by weight, (D) one or more kinds of fibrous, powdery, and plate-like fillers in an amount of 0 to 100 parts by weight, and blended and melt-kneaded to form a polyester resin composition for blow molding, and the resin composition. It is a hollow molded product manufactured by blow molding.

The constituent components of the composition of the present invention will be described in detail below. First, the present invention is characterized in that two specific types (A) and (B) of polyester resins are used in combination as the resin component.

The thermoplastic polyester resin (A) is a polyester whose main repeating unit is a 1,4-butylene terephthalate group, and may be either a homopolyester or a copolyester. Examples of the aromatic dicarboxylic acid compound constituting the thermoplastic polyester resin (A) include terephthalic acid or its ester-forming derivative as a main component, and other copolymerization components such as isophthalic acid and naphthalenedicarboxylic acid. , A known aromatic dicarboxylic acid such as diphenyldicarboxylic acid, and one or more selected from ester-forming derivatives thereof. Further, the polyester (A) of the present invention
1,2-butanediol as a main component of the dihydroxy compound, and other copolymerization components of ethylene glycol, propylene glycol, neopentyl glycol, hexanediol, cyclohexanediol, cyclohexanedimethanol, diethylene glycol, and triethylene glycol. Such aliphatic dihydroxy compounds and substitution products thereof may be used alone or in combination of two or more. As a comonomer component other than the above in order to have a special function, diphenyl ether dicarboxylic acid, α, β-bis (4-carboxyphenoxy)
Dicarboxylic acids such as ethane, adipic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, silokuhexanedicarboxylic acid, dimer acid or their ester forming derivatives, or pentanediol,
Neopentyl glycol, hexanediol, octanediol, decanediol, cyclohexanedimethanol, hydroquinone, bisphenol A, 2,2-bis (4'-hydroxyethoxyphenyl) propane, xylene glycol, polyethylene glycol, polytetramethylene glycol, both ends Is a glycol such as an aliphatic polyester oligomer having a hydroxyl group, further, glycolic acid, hydroxy acid, hydroxybenzoic acid, hydroxyphenylacetic acid, hydroxycarboxylic acid such as naphthylglycolic acid, propiolactone, butyrolactone, caprolactone, valerolactone, Lactone compounds such as caprolactone can also be used. Further, a polyester having a branched or crosslinked structure using a polyfunctional ester-forming component such as trimethylolpropane, trimethylolethane, pentaerythritol, trimellitic acid, trimesic acid, and pyromellitic acid within a range that can maintain thermoplasticity. May be Further, it may be a polyester using an ester-forming component having an ionic group such as sulfoisophthalic acid or sodium parahydroxyethylphenylsulfonate. Also, an aromatic nucleus such as dipromotelephthalic acid, tetrabromoterephthalic acid, tetrachloroterephthalic acid, 1,4-dimethyloltetrabromobenzene, tetrabromobisphenol A, an ethylene oxide or propylene oxide adduct of tetrabromobisphenol A. In addition, a polyester copolymer having a halogen compound as a substituent and having a halogen using a compound having an ester-forming group is also included. However, the basic condition of the component (A) is to use a 1,4-butylene terephthalate group as a main repeating unit, and it is preferable that the repeating unit is 70 mol% or more, particularly preferably 80 mol% or more. is there. The viscosity of the polyester resin (A) used in the present invention is not particularly limited and may be any as long as it can be melt-molded. Generally, one having an intrinsic viscosity of 0.6 to 2.0 can be used, and it is particularly low. It is a feature of the present invention that the blow moldability is remarkably improved by the combined use of the following components (B) and (C) even in the case of viscosity. However, if the viscosity itself is too high, the flowability will be deteriorated, which is not preferable.

Next, the present invention relates to the above-mentioned general formula as the component (B).
Thermoplastic polyester resin other than (A) shown in (1)
It is characterized by using (B) together. Here, the combination of -Ar- and -R- in the general formula (1) may be any combination shown above, and each may be two or more kinds shown above. It is necessary that the polyester resin has a different structure from that of the polyester resin, and a resin having a similar structure is not preferable because the effect of the present invention is difficult to obtain. As the polyester resin suitable as the component (B), a polyethylene terephthalate polymer, polyethylene naphthalate,
Polybutylene naphthalate, polytetramethylene glycol

[0009]

[Chemical 3]

Polyester elastomer having (n = 5-70) as a soft segment and polybutylene terephthalate and / or polyethylene terephthalate as a hard segment, terephthalic acid and isophthalic acid, and 2,2-bis (4-)
A polyester resin such as polyarylate composed of hydroxyphenyl) propane can be mentioned. These polyester resins (B) may be polyesters mainly composed of the above-exemplified polyesters and further supplemented with a small amount of other comonomers similar to those described in the description of the component (A) component polyester. Particularly preferred component (B) polyester is polyethylene terephthalate, the polyester elastomer, or a polyester mainly composed of polyarylate. Further, the polyester resin as the component (B) is not limited to one type, and two or more types may be used in combination in order to adjust the desired physical property values.

In the present invention, (A) a polyester resin and
(B) The blending ratio of the polyester resin is the resin component (A) and
It is 1 to 99 parts by weight per 100 parts by weight of the total amount of (B). Within this range, it is possible to use any compounding ratio so as to obtain the desired physical properties. Is not preferable because the effect of coexistence with is not sufficiently obtained. The polyester resin (A) has a high crystallinity, and in order to take advantage of its high physical properties, the polyester resin (A) is blended in an amount of 50 to 99 parts by weight and 50 to 1 parts by weight of the polyester resin (B). A ratio is often preferred, particularly preferably (A) :( B) is 60
~ 95: 40 ~ 5.

The present invention now seeks to improve blow moldability.
(C) is characterized by melt-kneading a specific styrene-based copolymer that is a component, and a specific amount of such styrene-based copolymer (C) as (A) and (B) component By blending and melt-kneading, the compatibility of the components (A) and (B) is improved, not only helping them to mix uniformly, but also the most important melt tension and drawdown in blow molding. It is particularly effective in significantly improving resistance and facilitating blow molding of a thermoplastic polyester resin, which has hitherto been impossible to blow mold. The styrene copolymer (C) is a copolymer containing styrene and a glycidyl ester of an α, β-unsaturated acid as essential components. In such a copolymer, the styrene unit constituting the copolymer is preferably 40 to 97% by weight, particularly preferably 50 to 95% by weight. The glycidyl ester of α, β-unsaturated acid, which is the other essential component constituting the copolymer of the component (C), is a compound represented by the following general formula (2):

[0013]

[Chemical 4]

(In the formula, R'is hydrogen or a lower alkyl group) For example, acrylic acid glycidyl ester, methacrylic acid glycidyl ester, ethacrylic acid glycidyl ester, itaconic acid glycidyl ester and the like are preferable, and methacrylic acid glycidyl ester is particularly preferable. The content of the glycidyl ester unit represented by the formula (2) in the styrene copolymer (C) is preferably 3 to 60% by weight, particularly preferably 5 to 50% by weight. If the content is too high, the composition tends to gel, causing a problem in blow moldability, and it is not preferable because it deteriorates the surface condition of the molded product. If it is too low, the melt tension,
The effect of improving blow moldability such as drawdown property cannot be obtained. Furthermore, the styrene-based copolymer (C) used in the present invention
Is a vinyl-based monomer other than the above two components.
It may be a multi-component copolymer which is copolymerized by using one or more kinds, and suitable examples of the third component include acrylonitrile, vinyl chloride, α-methylstyrene, brominated styrene, phenylmaleimide and the like. In particular, acrylonitrile is most suitable as the third component,
The terpolymer introduced in an amount of not more than 40% by weight, preferably not more than 40% by weight, has a further excellent effect in improving blow moldability. Further, it may be a multi-component copolymer into which a small amount of other vinyl-based monomer is supplementarily introduced as a subsidiary component other than these, but the inclusion of an olefin-based monomer such as ethylene, propylene, butene-1 is rather effective. It is not preferable because it causes deterioration, and particularly those containing 40% by weight or more of an olefin such as ethylene remarkably deteriorate the melt moldability, blow moldability such as drawdown property, and the surface condition of the molded product, which is not preferable. The styrene-based copolymer which is the component (C) of the present invention can be easily prepared by a usual radical polymerization method using the above-mentioned monomer and a radical polymerization catalyst.
The copolymer which is the component (C) of the present invention may be a graft copolymer in which a small amount of a vinyl polymer is further branched or cross-linked chemically bonded to the styrene linear copolymer. As the vinyl-based monomer constituting the branched or crosslinked segment, acrylic acid, acrylic acid alkyl ester, methacrylic acid, methacrylic acid alkyl ester,
Examples thereof include styrene and acrylonitrile. The copolymer having such a branched or crosslinked structure is obtained by, for example, copolymerizing at least one vinyl monomer and a radical-polymerizable organic peroxide in the presence of the styrene linear copolymer to give a peroxide group. A graft copolymer can be obtained by producing a content copolymer and kneading it by heating. However, the component (C) used in the present invention itself needs to be a fluid substance at the melt-kneading temperature, and if it is too highly grafted, the fluidity deteriorates and the dispersibility deteriorates. The improvement effect on blow molding decreases and the surface condition of the molded product deteriorates, which is not preferable. The compounding amount of the styrene copolymer as the component (C) is 0.2 to 10 parts by weight based on 100 parts by weight of the total of the components (A) and (B),
It is particularly preferably 0.5 to 8 parts by weight. If the blending amount is too small, the effect of improving blow moldability, etc., which is the object of the present invention, cannot be obtained, and if it is too large, the entire system tends to be gelled, which is not preferable.

The resin composition used for blow molding according to the present invention may further contain, as a component (D), a fibrous, powdery or plate-like filler as a component (D). Such a filler is effective in imparting mechanical properties to the molded product, particularly strength and rigidity. As the fibrous filler, glass fiber, asbestos fiber, carbon fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, further stainless steel,
Inorganic fibrous substances such as metal fibrous substances such as aluminum, titanium, copper and brass can be used. A particularly representative fibrous filler is glass fiber. On the other hand, as the particulate filler, carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate,
Silicates such as kaolin, talc, clay, diatomaceous earth, wollastonite, oxides of metals such as iron oxide, titanium oxide, zinc oxide, alumina, carbonates of metals such as calcium carbonate and magnesium carbonate, calcium sulfate, sulfuric acid. Sulfates of metals such as barium, other silicon carbide, silicon nitride,
Examples thereof include boron nitride and various metal powders. Examples of the plate-like filler include mica, glass flakes, various metal foils and the like. These inorganic fillers can be used alone or in combination of two or more. The combined use of fibrous fillers, especially glass fibers and powdery or granular or plate-like fillers is a preferable combination in terms of mechanical strength and dimensional accuracy of molded products, electrical properties, etc., and particularly improved blow moldability. It is also effective.
When using these fillers, it is desirable to use a sizing agent or a surface treatment agent. This example is a functional compound such as an epoxy compound, an isocyanate compound, a titanate compound, a silane compound. The amount of the filler as the component (D) in the present invention is the resin component.
100 parts by weight or less based on a total of 100 parts by weight of (A) and (B),
It is preferably 70 parts by weight or less. If the blending amount is small, the rigidity, strength, etc. tend to be low, and if it exceeds 100 parts by weight, molding is hindered, which is not preferable.

Further, in addition to the above, it is possible to supplementarily use a small amount of other thermoplastic resin in the resin composition of the present invention. Any other thermoplastic resin may be used as long as it is a thermoplastic resin that is stable at high temperatures. For example, styrene (co) polymers other than the above, polyamide (co) polymers, polycarbonate,
Examples thereof include polyphenylene oxide, polyalkyl acrylate, polyacetal, polysulfone, polyether sulfone, polyetherimide, polyetherketone, and fluororesin. Further, these thermoplastic resins may be used as a mixture of two or more kinds. Furthermore, in the resin composition of the present invention, known substances generally added to synthetic resins, that is, antioxidants, stabilizers such as ultraviolet absorbers and transesterification inhibitors, antistatic agents, flame retardants,
Colorants such as dyes and pigments, lubricants, release agents, crystallization accelerators, crystal nucleating agents and the like can be appropriately added depending on the required performance.

In the blow molding method of the present invention, a mixture of the above polyester resins (A) and (B) is added to the above styrene copolymer.
(C) is added and blended, melt-kneaded, and optionally other desired components are blended, melt-kneaded, and then subjected to blow molding. The melt-kneading of each component is a single-screw or twin-screw extruder. It is also possible to pelletize once by using and then subject to blow molding, or immediately after melt-kneading, it is possible to use as a parison for blow molding and to subject to molding. The blow molding of the present invention may be carried out by a usual method using a blow molding machine generally used for blow molding of thermoplastic resins. That is, the above resin composition is plasticized by an extruder or the like, and this is extruded or injected by an annular die to form an annular melted or softened intermediate parison, which is sandwiched by a mold to put a gas inside. It is blown, inflated, cooled and solidified, and molded as a hollow body. Molding conditions for the resin composition of the present invention are preferably performed at a cylinder and die temperature that is 5 to 60 ° C. higher than the melting point of the resin used, and the mold temperature is 40 to 130.
C. is preferable, but 80 to 100.degree. C. is particularly preferable. The gas blown into the inside may be air, nitrogen or the like, but air is usually used in consideration of economy, and the blowing pressure is preferably 3 to 10 kg / cm ² . Further, it can be molded by a special blow molding machine such as a three-dimensional blow molding machine.
It is also possible to prepare a multilayer blow-molded article by adding one or more layers of the composition of the present invention, or by combining layers of other materials.

[0018]

INDUSTRIAL APPLICABILITY The resin composition of the present invention has an improved melt tension as compared with the conventional polyester resin composition, there is no drawdown of the parison at the time of blow molding, and the blow moldability is remarkably improved. Also does not tend to gel, maintains stable fluidity, can efficiently obtain a relatively large hollow molded product with uniform wall thickness and good appearance, and also has good mechanical properties and heat resistance. It is also excellent, and it can be used under extremely severe conditions such as intake and exhaust parts around the engine such as automobile intake manifold, containers for high temperature liquids, chemicals, solvents, containers such as pipes and floats, and tubular objects (including irregular shapes). A possible hollow molded article can be provided.

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Examples 1 to 11 and Comparative 1 to 5 As shown in Table 1, a mixture of a polybutylene terephthalate resin (PBT) having an intrinsic viscosity of 1.0 as a component (A) and a polyester resin other than PBT listed in the table as a component (B) 100
(C) Styrene-glycidyl methacrylate copolymer was blended in parts by weight and melt-kneaded with a twin-screw extruder to prepare pellets of the resin composition. Next, using this pellet,
Blow molding machine (S-45ND, manufactured by Placo Co., Ltd.), temperature of die (die diameter 50mm, die interval 3mm) unless otherwise specified
250 ℃, mold temperature 80 ℃, blow pressure 5kg / cm ² , average thickness
A cylindrical hollow container of 2.5 mm and an internal capacity of 500 cc was molded, and the moldability (drawdown, breakage during blowing, uniformity of wall thickness of molded product, appearance (rough skin, surface irregularities)) was evaluated. The results are shown in Table 1. For comparison, the same test was performed in the case where the component (C) was blended with the resin component (A) or (B) alone as shown in Table 2. The results are shown in Table 2. The measuring methods used for evaluating the characteristic values are as follows. 1) Melt tension Capillary rheometer, 2 unless otherwise stated
The load at the time of dropping the resin flowing out from the orifice having a diameter of 1 mm at 55 ° C. and taking it out at a ratio of 10 was measured by a load cell. 2) Blow moldability / drawdown The ratio of the time until the length of the parison extruded from the blow molding machine reaches 120 mm and the time until it reaches 600 mm was evaluated as a drawdown index. The drawdown index is 5 for a resin that has no drawdown and 1 for a resin that immediately draws down.・ Breakage at the time of blowing Judgment was made based on whether or not the material was visually torn during blow molding.・ Uniformity of wall thickness of the molded product After cutting the molded product, the thickness of three parts of each of the upper part, the center part and the lower part of the cylinder is measured with a micrometer, and the fluctuation of the thickness (the maximum value and the minimum value with respect to the average thickness) % Difference) was examined. -Appearance The surface smoothness (irregularities) was visually observed and ranked as excellent, good or bad. Examples 12 to 14 and Comparative Examples 6 to 10 (C) The kinds and amounts of the components were changed, and the test evaluation was carried out according to the above examples. Further, for comparison, the test was also conducted in the case where the component (C) was not blended. The results are shown in Table 3.

Examples 15 to 17 and Comparative Examples 11 to 14 The same tests and evaluations were carried out in the case where glass fiber was added as a filler. The results are shown in Table 4.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

* 1 PET: Polyethylene terephthalate Polyester elastomer: Polybutylene terephthalate (58% by weight) as a hard segment and polybutylene glycol (average degree of polymerization n = 14) (42% by weight) as a soft segment Block copolymer polyarylate : A wholly aromatic polyester containing terephthalic acid (20% by weight) and isophthalic acid (80% by weight) as acid components and 2,2-bis (4-hydroxyphenyl) propane as a diol component * 2 S / G: styrene / Glycidyl methacrylate (80
/ 20 weight ratio) S / AN / G: Styrene / acrylonitrile / glycidyl methacrylate (56/24/20 weight ratio) * 3 Measurement temperature 270 ° C * 4 Measured with a drawdown ratio of 2

[Procedure amendment]

[Submission date] July 20, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

(In the formula, R'is hydrogen or a lower alkyl group) For example, acrylic acid glycidyl ester, methacrylic acid glycidyl ester, ethacrylic acid glycidyl ester, itaconic acid glycidyl ester and the like are preferable, and methacrylic acid glycidyl ester is particularly preferable. The content of the glycidyl ester unit represented by the formula (2) in the styrene copolymer (C) is preferably 3 to 60% by weight, particularly preferably 5 to 50% by weight. If the content is too high, the composition tends to gel, causing a problem in blow moldability, and it is not preferable because it deteriorates the surface condition of the molded product. If it is too low, the melt tension,
The effect of improving blow moldability such as drawdown property cannot be obtained. Furthermore, the styrene-based copolymer (C) used in the present invention
Is a vinyl-based monomer other than the above two components.
It may be a multi-component copolymer which is copolymerized by using one or more kinds, and suitable examples of the third component include acrylonitrile, vinyl chloride, α-methylstyrene, brominated styrene, phenylmaleimide and the like. In particular, acrylonitrile is most suitable as the third component,
The terpolymer introduced in an amount of not more than 40% by weight, preferably not more than 40% by weight, has a further excellent effect in improving blow moldability. Further, it may be a multi-component copolymer into which a small amount of other vinyl-based monomer is supplementarily introduced as a subsidiary component other than these, but the inclusion of an olefin-based monomer such as ethylene, propylene, butene-1 is rather effective. It is not preferable because it causes a decrease. Particularly, those containing 40% by weight or more of an olefin such as ethylene are not preferable because they significantly deteriorate the melt tension, blow moldability such as drawdown property, and the surface condition of the molded product. The styrene-based copolymer which is the component (C) of the present invention can be easily prepared by a usual radical polymerization method using the above-mentioned monomer and a radical polymerization catalyst.
The copolymer which is the component (C) of the present invention may be a graft copolymer in which a small amount of a vinyl polymer is further branched or cross-linked chemically bonded to the styrene linear copolymer. As the vinyl-based monomer constituting the branched or crosslinked segment, acrylic acid, acrylic acid alkyl ester, methacrylic acid, methacrylic acid alkyl ester,
Examples thereof include styrene and acrylonitrile. Such a copolymer having a branched or crosslinked structure can be obtained by, for example, copolymerizing at least one vinyl monomer and a radical-polymerizable organic peroxide in the presence of the styrene linear copolymer to obtain a peroxide group. A graft copolymer can be obtained by producing a content copolymer and kneading it by heating. However, the component (C) used in the present invention itself needs to be at least a fluid substance at the melt-kneading temperature, and preferably the melt viscosity of the component (C) is the main resin component at the melt-kneading temperature. It is desirable to use one lower than (A) or (B), and particularly preferably half or less of the main resin component. Those with a large molecular weight and high melt viscosity or those with a high degree of grafting have poor flowability and poor dispersibility in polyester, so the effect of improving blow moldability is diminished and the surface condition of the molded product also deteriorates. , Not preferable. The compounding amount of the styrene copolymer as the component (C) is 0.2 to 10 parts by weight, particularly preferably 0.5 to 8 parts by weight based on 100 parts by weight of the total of the components (A) and (B).
Parts by weight. If the blending amount is too small, the effect of improving blow moldability, etc., which is the object of the present invention, cannot be obtained, and if it is too large, the entire system tends to be gelled, which is not preferable.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

In the blow molding method of the present invention, a mixture of the above polyester resins (A) and (B) is added to the above styrene copolymer.
(C) is added and blended, melt-kneaded, and optionally other desired components are blended, melt-kneaded, and then subjected to blow molding. The melt-kneading of each component is a single-screw or twin-screw extruder. It is also possible to pelletize once by using and then subject to blow molding, or immediately after melt-kneading, it is possible to use as a parison for blow molding and to subject to molding. The composition of the present invention may be prepared by melt-kneading the required components at once, or a composition having a part of the required components may be prepared in advance, and these may be mixed before molding to give a predetermined composition. It may be prepared to be a component (masterbatch method), or a specific component,
For example, the component (C) or its masterbatch may be added and blended in two or more times. In particular, when the molded product is regenerated and reused, it is preferable that the component (C) or its masterbatch is additionally compounded and then used for molding. The blow molding of the present invention may be carried out by a usual method using a blow molding machine generally used for blow molding of thermoplastic resins. That is, the above resin composition is plasticized by an extruder or the like, and this is extruded or injected by an annular die to form an annular melted or softened intermediate parison, which is sandwiched by a mold to put a gas inside. It is blown, inflated, cooled and solidified, and molded as a hollow body. As molding conditions for the resin composition of the present invention, it is preferable to carry out at a cylinder and die temperature which is 5 to 60 ° C. higher than the melting point of the resin used, and the mold temperature is 40
The temperature is preferably ~ 130 ° C, particularly preferably 80 ~ 100 ° C. The gas blown into the inside may be air, nitrogen or the like, but air is usually used in consideration of economy, and the blowing pressure is preferably 3 to 10 kg / cm ² . Further, it can be molded by a special blow molding machine such as a three-dimensional blow molding machine. It is also possible to prepare a multilayer blow-molded article by adding one or more layers of the composition of the present invention, or by combining layers of other materials.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. Examples 1 to 11 and Comparative Examples 1 to 5 As shown in Table 1, a mixture of a polybutylene terephthalate resin (PBT) having an intrinsic viscosity of 1.0 as a component (A) and a polyester resin other than PBT listed in the table as a component (B). 100
(C) Styrene-glycidyl methacrylate copolymer was blended in parts by weight and melt-kneaded with a twin-screw extruder to prepare pellets of the resin composition. Next, using this pellet,
Blow molding machine (S-45ND, manufactured by Placo Co., Ltd.), temperature of die (die diameter 50mm, die interval 3mm) unless otherwise specified
250 ℃, mold temperature 80 ℃, blow pressure 5kg / cm ² , average thickness
A cylindrical hollow container of 2.5 mm and an internal capacity of 500 cc was molded, and the moldability (drawdown, breakage during blowing, uniformity of wall thickness of molded product, appearance (rough skin, surface irregularities)) was evaluated. The results are shown in Table 1. For comparison, the same test was performed in the case where the component (C) was blended with the resin component (A) or (B) alone as shown in Table 2. The results are shown in Table 2. The measuring methods used for evaluating the characteristic values are as follows. 1) Melt tension Capillary rheometer, 2 unless otherwise stated
The load at the time of dropping the resin flowing out from the orifice having a diameter of 1 mm at 55 ° C. and taking it out at a ratio of 10 was measured by a load cell. 2) Blow moldability / drawdown The ratio of the time until the length of the parison extruded from the blow molding machine reaches 120 mm and the time until it reaches 600 mm was evaluated as a drawdown index. The drawdown index is 5 for a resin that has no drawdown and 1 for a resin that immediately draws down.・ Breakage at the time of blowing Judgment was made based on whether or not the material was visually torn during blow molding.・ Uniformity of wall thickness of the molded product After cutting the molded product, the thickness of three parts of each of the upper part, the center part and the lower part of the cylinder is measured with a micrometer, and the fluctuation of the thickness (the maximum value and the minimum value with respect to the average thickness) % Difference) was examined. -Appearance The surface smoothness (irregularities) was visually observed and ranked as excellent, good or bad. Examples 12 to 14 and Comparative Examples 6 to 11 (C) By changing the kinds and amounts of the components, test evaluation was carried out according to the above examples. For comparison, if component (C) is not used,
A test was also conducted for the case where a substance similar to the component (C), which does not satisfy the requirements of the present invention, was incorporated. The results are shown in Table 3.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

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Examples 15 to 17 and Comparative Examples 12 to 15 The same tests and evaluations were carried out in the case of incorporating glass fiber as the filler. The results are shown in Table 4.

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[Table 3]

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[Table 4]

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* 1 PET: Polyethylene terephthalate Polyester elastomer: Polybutylene terephthalate (58% by weight) as a hard segment and polybutylene glycol (average degree of polymerization n = 14) (42% by weight) as a soft segment Block copolymer polyarylate : A wholly aromatic polyester containing terephthalic acid (20% by weight) and isophthalic acid (80% by weight) as acid components and 2,2-bis (4-hydroxyphenyl) propane as a diol component * 2 S / G: styrene / Glycidyl methacrylate (80
/ 20 weight ratio) S / AN / G: styrene / acrylonitrile / glycidyl methacrylate (56/24/20 weight ratio) E / G: ethylene / glycidyl methacrylate (80/20
Weight ratio) * 3 Measurement temperature 270 ℃ * 4 Measured at drawdown ratio 2

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Claims (7)

[Claims] 1. A thermoplastic polyester resin (A) whose main repeating unit comprises a 1,4-butylene terephthalate group.
~ 99 parts by weight, and (B) the main repeating unit is the following general formula
(1) a thermoplastic polyester resin other than (A) having an ester group represented by (1) 99 to 1 part by weight, and a resin component 1
[Chemical formula 1] for 00 parts by weight (C) Styrene 40 to 97% by weight, α, β-unsaturated glycidyl ester 60 to 3% by weight, other vinyl monomers 0 to
0.2 to 10 parts by weight of a styrene-based copolymer composed of 50% by weight,
(D) A polyester resin composition for blow molding, which is prepared by mixing 0 to 100 parts by weight of one or more of fibrous, powdery, and plate-like fillers and melt-kneading. 2. The styrene copolymer (C) is at least one of acrylonitrile, vinyl chloride, α-methylstyrene, brominated styrene and phenylmaleimide, in addition to styrene and glycidyl ester of α, β-unsaturated acid. The polyester resin composition for blow molding according to claim 1, which is a copolymer containing 3. The polyester resin composition for blow molding according to claim 1, wherein the thermoplastic polyester resin (B) is a thermoplastic polyester polymer or copolymer having an ethylene terephthalate group as a main repeating unit. 4. The thermoplastic polyester resin (B) is a polyester elastomer copolymer mainly composed of polytetramethylene glycol as a soft segment and a 1,4-butylene terephthalate group as a hard segment. Polyester resin composition for blow molding. 5. The thermoplastic polyester resin (B) is a copolymerized polyester mainly containing 2,2-bis (4-hydroxyphenyl) propane as a diol component and terephthalic acid and isophthalic acid as acid components. The polyester resin composition for blow molding according to 2. 6. The blow molding polyester according to claim 1, wherein the thermoplastic polyester resin (A) is 50 to 99 parts by weight and the thermoplastic polyester resin (B) is 50 to 1 parts by weight. Resin composition. 7. A hollow molded product produced by blow molding using the polyester resin composition for blow molding according to any one of claims 1 to 6.