JP2002201346A - Polyester resin composition, method for producing the same and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester resin composition having more improved gas barrier properties and to provide a method for producing the resin composition and use thereof. SOLUTION: (C) This polyester resin composition comprises (A) a polyester composed of 5-85 mol% of terephthalic acid constituent units and 15-95 mol% of isophthalic acid constituent units based on the total dicarboxylic acid constituent units and 25-100 mol% of ethylene glycol constituent units and 0-75 mol% of 1,3-bis(2-hydroxyethoxy)benzene constituent units based on the total diol constituent units and (B) a layer inorganic filler.

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, a method for producing the same, and a use thereof, and more particularly, to a polyester resin composition having excellent gas barrier properties and rigidity, a method for producing the same, and a film comprising the polyester resin composition. And molded articles such as containers.

[0002]

BACKGROUND OF THE INVENTION Saturated polyesters such as polyethylene terephthalate are widely used as containers such as bottles because of their excellent gas barrier properties, transparency and mechanical strength. In particular, bottles obtained by biaxially stretch blow molding polyethylene terephthalate are excellent in transparency, mechanical strength, heat resistance and gas barrier properties, and are used for filling beverages such as juices, soft drinks and carbonated drinks (P
ET bottles).

[0003] In recent years, bottles made of polyester resin (particularly polyethylene terephthalate) have tended to be miniaturized. However, in the case of such a small bottle, the area in contact with the bottle body per unit capacity has been increased, so that gas has to be reduced. The effect on the contents due to loss or permeation of oxygen from the outside becomes remarkable, and the storage period of the contents is reduced. For this reason, polyester resins used for small containers are required to have better gas barrier properties than before.

As an attempt to improve the heat resistance and gas barrier properties of a polyester resin, for example, Japanese Patent Publication No. 1-23022 proposes blending polyethylene terephthalate with polyethylene isophthalate. JP-B-63-40444 discloses that isophthalic acid or terephthalic acid, ethylene glycol and 1,3-
A method for producing a copolyester comprising bis (2-hydroxyethoxy) benzene has been proposed. However, in order to satisfy the above requirements, polyesters having further improved gas barrier properties are desired.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has as its object to provide a polyester resin composition having improved gas barrier properties, a process for producing the same, and a use thereof. .

[0006]

SUMMARY OF THE INVENTION The polyester resin composition (C) according to the present invention comprises (A) 5-85 mol% of a structural unit derived from terephthalic acid, based on all dicarboxylic acid structural units.
It contains a constituent unit derived from isophthalic acid in a proportion of 15 to 95 mol%, and a constituent unit derived from ethylene glycol is used in an amount of 25 to 100 based on all diol constituent units.
Mol%, a polyester containing a structural unit derived from 1,3-bis (2-hydroxyethoxy) benzene in a proportion of 0 to 75 mol%, and (B) a layered inorganic filler. .

The polyester resin composition (C) preferably contains 100 parts by weight of the polyester (A) and 0.1 to 10 parts by weight of the layered inorganic filler (B). The polyester resin composition (E) according to the present invention comprises the polyester (A) and the layered inorganic filler (B).
And polyethylene terephthalate (D).

[0008] The molded article according to the present invention is characterized by comprising the above polyester resin composition (E). A molded article according to another aspect of the present invention is a molded article having a multilayer structure, wherein at least one layer is formed from the polyester resin composition (E).

Examples of the molded article of the polyester resin composition (E) and the multilayered molded article having at least one layer of the polyester resin composition (E) include an injection molded article, a blow molded article, and an extrusion molded article. There are a body, a preform, a biaxially stretched bottle blow-molded from the preform, an extruded sheet, an extruded film and the like. The method for producing a polyester composition (E) according to the present invention comprises the above-mentioned polyester (A), (B) a layered inorganic filler,
(D) After melt-kneading with polyethylene terephthalate, the obtained melt-kneaded product is subjected to a polycondensation reaction in a solid phase.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The polyester resin composition according to the present invention, its production method and use will be described below. Polyester resin composition (C) The polyester resin composition (C) according to the present invention comprises a polyester (A) and a layered inorganic filler (B).

(Polyester (A)) The polyester (A) used in the present invention comprises a structural unit derived from terephthalic acid, a structural unit derived from isophthalic acid,
It consists of a structural unit derived from ethylene glycol and a structural unit derived from 1,3-bis (2-hydroxyethoxy) benzene.

The polyester (A) contains structural units derived from terephthalic acid in a proportion of 5 to 85 mol%, preferably 10 to 50 mol%, based on all dicarboxylic acid structural units, and 1 derived unit
It is contained in an amount of 5 to 95 mol%, preferably 50 to 90 mol%, and a structural unit derived from ethylene glycol is 25 to 100 mol%, preferably 35 to 99.5 mol based on all diol structural units. %, More preferably 50 to
It is contained in an amount of 99.5 mol%, and the structural unit derived from 1,3-bis (2-hydroxyethoxy) benzene is 0 to 75 mol%, preferably 0.5 to 75 mol%, based on all diol structural units. 65 mol%, more preferably 0.5 to 50 mol%.

The polyester (A) having such a composition is excellent in gas barrier properties. The polyester (A) may contain 15 mol% of dicarboxylic acid structural units derived from dicarboxylic acids other than isophthalic acid and terephthalic acid based on the total dicarboxylic acid structural units as long as the object of the present invention is not impaired. It may be contained in a proportion of less than.

Specific examples of such other dicarboxylic acids include phthalic acid (orthophthalic acid), 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, diphenyldicarboxylic acid , Aromatic dicarboxylic acids such as diphenoxyethane dicarboxylic acid; succinic acid, glutaric acid, adipic acid, sebacic acid,
Aliphatic dicarboxylic acids such as azelaic acid and decanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

These other dicarboxylic acids may be used in combination of two or more. Further polyester (A)
Is a diol structural unit derived from other diols other than ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene with respect to all the diol structural units as long as the object of the present invention is not impaired. It may be contained in a proportion of less than 15 mol%.

Specific examples of such other diols include diethylene glycol, triethylene glycol,
Tetraethylene glycol, trimethylene glycol,
Aliphatic glycols such as propylene glycol, butanediol, pentanediol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol; alicyclic glycols such as cyclohexanedimethanol; 1,2-bis (2-hydroxyethoxy) benzene , 1,
Glycols containing an aromatic group such as 4- (2-hydroxyethoxy) benzene; bisphenols, hydroquinone,
And aromatic diols such as 2,2-bis (4-β-hydroxyethoxyphenyl) propane.

These other diols may be used in combination of two or more. As the other diols, diethylene glycol is preferable among these. Further, the polyester (A) may be a composition derived from a polyfunctional carboxylic acid having three or more carboxyl groups or a polyhydric alcohol having three or more hydroxy groups as long as the object of the present invention is not impaired. May contain a unit, for example, trimellitic acid, trimesic acid, polyfunctional carboxylic acids such as pyromellitic anhydride; glycerin, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, A small amount of structural units derived from polyhydric alcohols such as 1,1,1-trimethylolmethane and pentaerythritol, for example, 2 mol% or less (the total of all dicarboxylic acid structural units and all diol structural units is 100 mol% ).

The polyester (A) used in the present invention has an intrinsic viscosity (IV) of preferably 0.5 to 1.5 dl /.
g, more preferably 0.6 to 1.5 dl / g, even more preferably 0.7 to 0.9 dl / g. The intrinsic viscosity (IV) is calculated from the solution viscosity measured at 25 ° C. after heating and dissolving 1.2 g of polyester in 15 cc of o-chlorophenol.

The polyester (A) can be produced, for example, by conducting an esterification (ester exchange) reaction and a subsequent polycondensation reaction. For example, terephthalic acid, a dicarboxylic acid containing isophthalic acid and a diol containing ethylene glycol and 1,3-bis (2-hydroxyethoxy) benzene are directly esterified, and then a germanium compound such as germanium dioxide; antimony trioxide; Antimony compounds such as antimony acetate; a method of melt polycondensation in the presence of a polycondensation catalyst such as a titanium compound such as titanium tetraalkoxide; terephthalic acid ester, isophthalic acid ester, ethylene glycol, 1,3-bis (2-hydroxyethoxy) benzene and titanium alkoxide such as titanium isopropoxide and titanium tetrabutoxide, cobalt acetate, zinc acetate,
After transesterification in the presence of a transesterification catalyst such as manganese acetate, metal acetate such as calcium acetate,
Germanium compounds such as germanium dioxide, antimony trioxide, antimony compounds such as antimony acetate,
It can be produced by a method of melt polycondensation in the presence of a polycondensation catalyst such as a titanium compound such as titanium tetraalkoxide.

(Layered Inorganic Filler (B)) The layered inorganic filler (B) used in the present invention usually has a form in which a number of layered clays are laminated, and an ionic component is contained between the layers. Have been. The layered clay is mainly composed of silicon and oxygen, and may further include crustal constituent elements such as aluminum, magnesium and iron. As the layered inorganic filler (B), those having a cation exchange capacity are preferable.

Specific examples of the layered inorganic filler (B) include:
Examples include smectite-based minerals such as montmorillonite, saponite, hyderite, heftrite and stevensite, vermiculite, halosite, and swelling mica (mica). It is important that the layered inorganic filler (B) has a property of intercalating organic cations between layers, and therefore, swellable minerals are suitable among these, and swellable mica and montmorillonite are particularly suitable. . The layered inorganic filler (B) may be natural or synthetic.

The ionic component contained between the layers preferably contains an organic onium ion derived from an organic ammonium salt or an organic phosphate. Examples of the organic ammonium salt include ammonium salts having a long alkyl chain such as octyltrimethylammonium salt, dioctyldimethylammonium salt, and trioctylmethylammonium salt; ammonium salts having an aliphatic ring such as trimethylcyclohexylammonium salt; methoxymethyltrimethylammonium Ammonium salts having an ether bond such as a salt; ammonium salts containing an element of Group 17 of the periodic table such as 2-bromoethyltrimethylammonium salt; Among them, ammonium salts having a long alkyl chain such as trioctylmethyl ammonium salt are preferable.

Examples of the organic phosphate include phosphonium salts having a long alkyl chain, such as octyltrimethylphosphonium salt, dioctyldimethylphosphonium salt, and trioctylmethylphosphonium salt; trimethylcyclohexylphosphonium salt Phosphonium salts having an aliphatic ring, such as methoxymethyltrimethylphosphonium salts; phosphonium salts having an ether bond, such as methoxymethyltrimethylphosphonium salts; phosphonium salts including Group 17 of the periodic table, such as 2-bromoethyltrimethylphosphonium salts; And the like. Of these, phosphonium salts having a long alkyl chain such as trioctylmethylphosphonium salt are preferred.

Such organic cations contained between the layers are preferably in the range of 20 to 100%, particularly 40 to 100%, based on all the cation components in the layers. A method for producing the layered inorganic filler (B) having an organic cation between layers as described above is known, and is disclosed, for example, in JP-A-3-62.
It can be produced by the method described in JP-A-846.

(Composition) In the polyester resin composition (C) according to the present invention, the layered inorganic filler (B) is used in an amount of 0.1 to 10 parts by weight, preferably 100 parts by weight of the polyester (A). Is preferably contained in an amount of 0.1 to 7.0 parts by weight. The polyester resin composition (C) containing such components in such amounts has excellent gas barrier properties.

The polyester resin composition (C) can be produced by melt-mixing the polyester (A) and the layered inorganic filler (B) by an ordinary method using an extruder or the like. Further, a polyester production method comprising at least an esterification reaction step of subjecting a dicarboxylic acid and a diol to an esterification reaction, and a liquid phase polycondensation step of subjecting the esterified product obtained in the esterification reaction step to a polycondensation reaction in a liquid phase. In the above, it is also possible to produce the polyester resin composition (C) by performing the polycondensation reaction in the liquid phase in the presence of the layered inorganic filler (B).

Polyester Resin Composition (E) The polyester resin composition (E) according to the present invention comprises the above polyester (A), a layered inorganic filler (B), and polyethylene terephthalate (D). (Polyethylene terephthalate (D)) The polyethylene terephthalate (D) used in the present invention comprises a structural unit derived from terephthalic acid and a structural unit derived from ethylene glycol.

As long as the object of the present invention is not impaired, the polyethylene terephthalate (D) may contain a structural unit derived from an aromatic dicarboxylic acid other than terephthalic acid in a proportion of less than 15 mol% based on all dicarboxylic acid structural units. May be contained. Specific examples of aromatic dicarboxylic acids other than terephthalic acid include isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, and diphenoxyethanedicarboxylic acid.

Further, polyethylene terephthalate (D)
May contain a structural unit derived from a diol other than ethylene glycol in a proportion of less than 15 mol% with respect to all diol structural units as long as the object of the present invention is not impaired. Specific examples of diols other than ethylene glycol include diethylene glycol, triethylene glycol, tetraethylene glycol, trimethylene glycol (propylene glycol), butanediol,
Examples include aliphatic glycols such as pentanediol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, and polyethylene glycol; alicyclic glycols such as cyclohexanedimethanol; bisphenols; and aromatic diols such as hydroquinones.

Further, polyethylene terephthalate (D)
Is a small amount of a unit derived from a polyfunctional carboxylic acid having three or more carboxyl groups or a polyhydric alcohol having three or more hydroxy groups as long as the object of the present invention is not impaired. For example, it may be contained at a ratio of 2 mol% or less (the total of all the dicarboxylic acid structural units and all the diol structural units is 100 mol%).

The polyethylene terephthalate (D) is substantially linear, which is confirmed by the fact that the polyethylene terephthalate dissolves in o-chlorophenol. Polyethylene terephthalate (D) is a 1: 1 mixture of phenol and tetrachloroethane.
(Weight ratio) The intrinsic viscosity (IV) measured at 25 ° C. in a mixed solvent is usually in the range of 0.3 to 1.5 dl / g, preferably 0.5 to 1.2 dl / g. .

The polyethylene terephthalate (D) used in the present invention is produced from terephthalic acid, ethylene glycol or the like by a conventionally known production method. (Composition) The polyester composition (E) according to the present invention comprises:
The polyester (A) is 5-95 parts by weight, especially 10-80 parts by weight, and the layered inorganic filler (B) is 100 parts by weight of the polyethylene terephthalate (D) and 100 parts by weight of the composition (E). Preferably, it is contained in an amount of 0.1 to 10 parts by weight, especially 0.5 to 10 parts by weight.

The polyester resin composition (E) containing such components in such amounts has excellent gas barrier properties. The polyester resin composition (E) according to the present invention is obtained by melt-kneading the polyester (A), the layered inorganic filler (B), and the polyethylene terephthalate (D), and then mixing the obtained melt-kneaded product with a solid phase. To produce a polycondensation reaction.

For the melt kneading, for example, a Henschel mixer,
A method of mixing with a V blender, a ribbon blender, a tumbler blender, and the like, and further, melt-mixing with an extruder, a kneader, a Banbury mixer, or the like is used.
At that time, after the above-mentioned three components of the polyester (A), the layered inorganic filler (B) and the polyethylene terephthalate (D) are dry-blended at a time, they may be melt-kneaded. After dry-blending any two components, After melt-kneading and further dry-blending the remaining components to the obtained kneaded product, the mixture may be melt-kneaded.

Next, a method of subjecting the thus obtained melt-kneaded product to a polycondensation reaction in a solid phase will be described. The thus obtained melt-kneaded product is usually formed into particles (chip shape) by a melt extrusion molding method. The granular polyester preferably has an average particle size of usually 2.0 to 5.0 mm. The obtained granular polyester resin composition is supplied to a solid phase polycondensation step.

The granular polyester resin composition may be heated to a temperature lower than the temperature at which the solid-phase polycondensation is carried out, preliminarily crystallized, and then supplied to the solid-phase polycondensation step. The pre-crystallization step may be performed by heating the granular polyester resin composition in a dry state, for example, at a temperature of 120 to 200 ° C. for 1 minute to 4 hours, or by subjecting the granular polyester resin composition to a steam atmosphere. It may be carried out by heating at a temperature of, for example, 120 to 200 ° C. for 1 minute or more in a steam-containing inert gas atmosphere or a steam-containing air atmosphere.

The solid phase polycondensation step in which the granular polyester resin composition is supplied comprises at least one stage, the polycondensation temperature is usually 190 to 230 ° C., and the pressure is usually 1 kg.
The solid-phase polycondensation reaction is carried out under an atmosphere of an inert gas such as nitrogen gas, argon gas, or carbon dioxide under the conditions of / cm ² G to 10 Torr. Among these inert gases, nitrogen gas is preferred.

The intrinsic viscosity of the polyester resin composition (E) thus obtained is usually desirably 0.50 dl / g or more. The density of the polyester resin composition (E) is usually desirably 1.37 g / cm ³ or more. Layered inorganic filler (B) used here
May be swollen with a raw material diol such as ethylene glycol.

The method for swelling the layered inorganic filler (B) with a raw material diol such as ethylene glycol is not particularly limited. Any method such as a method of immersing for 1 to 5.0 hours, a method of heating and stirring with the layered inorganic filler (B) dispersed in the diol, a method of ultrasonic treatment, and a method of shaking can be adopted.

When the layered inorganic filler (B) is swollen with a raw material diol such as ethylene glycol, the interlayer between the layered inorganic filler (B) is expanded by swelling, and the layered inorganic filler (B) is expanded during solid phase polymerization. The agent (B) is easily exfoliated in a scale-like manner. The polyester resin composition (E) obtained by performing the solid-phase polycondensation in the presence of the layered inorganic filler (B) as described above is a polyester resin composition obtained without melt-kneading and then without solid-phase polymerization. It is superior to the following items in the following points. (1) Since the layered inorganic filler (B) exfoliates in a scale-like manner and is easily dispersed, there is no generation of foreign substances (inorganic fillers that can be visually confirmed). For this reason, the appearance is more excellent. (2) Thread breakage is less likely to occur when the yarn is formed. (3) Superior transparency. (4) The gas barrier properties of the molded product are more excellent. (5) When formed into a sheet, the polyester resin composition obtained by melt-kneading the layered inorganic filler (B) by a usual method (without solid-phase polymerization) may contain a large amount of foreign matter, and the sheet may break. However, the polyester resin composition obtained by solid-state polymerization after melt-kneading can easily form a sheet having an excellent appearance.

Molded articles Examples of molded articles obtained from the polyester resin composition (E) according to the present invention include injection molded articles, blow molded articles, extruded molded articles, and thermoformed articles. In particular, injection moldings,
Blow moldings and extrusion moldings are preferred. Further, as the shape, it can be used after being formed into various shapes such as a film / sheet shape, a plate shape, a tubular shape, and a hollow shape.

Specific examples of such a molded article include a container such as a film / sheet, a preform for a bottle, and a bottle formed by biaxially stretch-blow-molding the preform. It is suitable for use in containers, packaging films and the like. Techniques for obtaining such a molded product are already known, and in the present invention, a molded product having a desired shape can be obtained by using these known molding methods.

Since the molded article according to the present invention is formed from the polyester resin composition (E) containing the polyester (A), the layered inorganic filler (B) and the polyethylene terephthalate (D), it has excellent gas barrier properties. ing. Multilayer molded article The multilayer molded article according to the present invention comprises two or more layers, and at least one layer is formed from the polyester resin composition (E).

Examples of the other layers include thermoplastic resin layers other than the polyester resin composition (E), metal layers, and paper layers. As a thermoplastic resin,
Polyolefin such as polyethylene, polypropylene, ethylene-vinyl alcohol copolymer; polyamide; polyester such as polyethylene terephthalate; polystyrene; ABS;
Examples of the metal include aluminum.

The respective layers may be directly laminated, or an adhesive layer made of an adhesive resin may be interposed between the respective layers. Although the thickness of the laminate is not particularly limited, it is usually 0.0
It is preferably in the range of 1 to 6.0 mm, particularly 0.02 to 5.5 mm. Among them, the thickness of the layer made of the polyester resin composition (E) is not particularly limited, but is usually 0.5 to 50% of the total thickness, particularly 0.5 to 50%.
Preferably it is in the range of 40%.

The method for producing the laminate includes a coextrusion molding method and a sandwich lamination method. Examples of the multilayer molded article include an injection molded article, a blow molded article, an extruded molded article, and a thermoformed article. Among them, injection moldings, blow moldings, and extrusion moldings are preferred.

Specific examples of such a molded article include containers such as a film / sheet, a preform for a bottle, and a bottle formed by biaxially stretch-blow-molding the preform, and particularly a hollow molded container. It is preferably used for packaging films and the like. When used as a container, it is preferable that the polyester resin composition (E) layer be an inner layer from the viewpoint of improving food hygiene, food taste retention, and gas barrier properties.

Techniques for obtaining such a multilayer molded product are already known, and in the present invention, a molded product having a desired shape can be obtained by using these known molding methods.
The multilayer molded article according to the present invention includes a layer made of the polyester resin composition (C) and thus has excellent gas barrier properties.

[0049]

The polyester resin composition (C) according to the present invention has an excellent gas barrier property against oxygen and carbon dioxide. Accordingly, the gas barrier property of the molded article is reduced by blending the polyester resin composition (C) with polyethylene terephthalate or laminating the polyester resin composition (C) with another layer such as a thermoplastic resin. Not only can it be improved, but also excellent in moldability, transparency and recyclability.

The polyester resin composition (E) according to the present invention and a molded article thereof are excellent not only in gas barrier properties but also in moldability, transparency and recyclability. Since the multilayer molded article according to the present invention includes the layer made of the polyester resin composition (E), it is excellent not only in gas barrier properties but also in moldability, transparency and recyclability.

[0051]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. In the examples, each characteristic was measured as follows. (Intrinsic viscosity) 1 g / d using o-chlorophenol solvent
1 sample solution was prepared, the solution viscosity was measured using an Ubbelohde capillary viscometer at 25 ° C., and then o-chlorophenol was gradually added to measure the solution viscosity on the low concentration side.
The data were extrapolated to 0% concentration and determined.

(Carbon dioxide gas permeability coefficient (gas barrier property))
GL Science Co., Ltd. Gas Permeability Measurement System GP
The measurement was performed using M-250 at 23 ° C. and a relative humidity of 60%. The film used for the measurement was produced as follows. Stretched film: A 0.3 mm thick film was produced using a press molding machine at a mold temperature of 290 ° C., and this film was rapidly cooled at a cooling mold temperature of 0 ° C. to obtain an amorphous film.
Next, the amorphous film was simultaneously biaxially stretched 3 × 3 times at a temperature 15 ° C. higher than the glass transition temperature (Tg),
It was a stretched film.

(Crystallization temperature at the time of temperature rise) It was measured using a differential calorimeter (DSC) manufactured by PerkinElmer. 10 mg of the sample was weighed into a sample pan, heated from room temperature to 290 ° C. at a rate of 320 ° C./min under a nitrogen stream, and held for 10 minutes. Thereafter, the temperature was rapidly cooled to 30 ° C., maintained for 10 minutes, and then raised at a rate of 10 ° C./min. The peak of the crystallization temperature appearing between the glass transition temperature and the melting point was measured. Temperature.

[0054]

Example 1 A slurry composed of 332 g of polyethylene terephthalate (D-1) high-purity terephthalic acid and 143 g of ethylene glycol was prepared, and 0.042 was added thereto.
g of germanium dioxide and 0.080 g of phosphoric acid were added. The slurry is pressurized (absolute pressure: 1.7 kg /
(cm ² ) and heated to a temperature of 255 ° C. to carry out an esterification reaction until the esterification ratio became 95% to produce a low polymer. Subsequently, the low polymer was melt-polymerized at a temperature of 280 ° C. under a reduced pressure of 1 Torr to obtain an intrinsic viscosity of 0.615.
dl / g of polyethylene terephthalate (D-1) was produced, extruded from a nozzle into a strand, and cut into cylindrical pellets having a diameter of 2.5 mm and a height of 3.5 mm. The heating crystallization temperature of this polyethylene terephthalate (D-1) was 158 ° C.

Copolyester (A-1) A slurry comprising 299 g of isophthalic acid, 33 g of terephthalic acid, 122 g of ethylene glycol and 21 g of 1,3-bis (2-hydroxyethoxy) benzene was prepared. Germanium and 0.080
g of phosphoric acid was added. This slurry is pressurized (absolute pressure:
The mixture was heated to a temperature of 255 ° C. at a pressure of 1.7 kg / cm ² ) and an esterification reaction was carried out until the esterification ratio reached 95% to produce a low polymer. Then, under a reduced pressure of 1 Torr, 28
The low polymer was melt-polymerized at a temperature of 0 ° C. to obtain a prepolymer of a polyethylene isophthalate copolymer (B-1) having an intrinsic viscosity of 0.815 dl / g (isophthalic acid: terephthalic acid (molar ratio) = 90). : 10, ethylene glycol: 1,
3-bis (2-hydroxyethoxy) benzene (molar ratio) =
85:15), which is extruded from a nozzle into a strand and cut, and has a diameter of 2.5 mm and a height of 3.5 m.
m cylindrical pellets.

Blend of layered inorganic filler Copolyester (A-1) 9 obtained as described above
Synthetic mica (trade name: 4C-TS, trade name: 4C-TS)
Topy Industries) 6 parts by weight dry blended,
It is melt-kneaded at a molding temperature of 275 ° C. using a 20 mmφ single screw extrusion molding device manufactured by Thermo Co., extruded into a strand shape from a nozzle and cut, and a columnar pellet having a diameter of 2.5 mm and a height of 3.5 mm (C-1). And

Blend with polyethylene terephthalate Then, 50 parts by weight of the obtained pellet (C-1) and 50 parts by weight of polyethylene terephthalate (D-1) were dry-blended using a 20 mmφ single screw extruder manufactured by Thermo. 2. Melt and knead at a molding temperature of 275 ° C., extrude into a strand shape from a nozzle and cut, 2.5 mm in diameter and 3 in height.
This was a 5 mm cylindrical pellet (E-1).

Solid Phase Polymerization Next, the pellet (E-1) obtained above was heated at 170 ° C. for 2 hours.
After preliminarily crystallization under a nitrogen stream for a period of time, solid phase polymerization was performed at 210 ° C. for 16 hours under a nitrogen atmosphere. The intrinsic viscosity of the polyester thus obtained is 0.860
dl / g. The stretched film obtained from this polyester has a carbon dioxide gas transmission coefficient of 4.6 cc · mm /
m ² · day · atm.

[0059]

Example 2 The polyethylene terephthalate (D) prepared in Blend Example 1 was used.
-1) 47 parts by weight of polyethylene isophthalate copolymer (A-1) and 6 parts by weight of synthetic mica obtained by exchanging interlayer ions with octyltrimethylammonium similar to that used in Example 1 Parts were melt-kneaded at a molding temperature of 275 ° C. using a 20 mmφ single screw extruder manufactured by Thermo Co., Ltd., and the melt-kneaded product was extruded from a nozzle into a strand and cut to obtain a diameter of 2.5 mm. And 3.5 mm high cylindrical pellets (E-2). The heated crystallization temperature of the melt-kneaded product was 158 ° C.

Solid Phase Polymerization The obtained pellet (E-2) was pre-crystallized at 170 ° C. for 2 hours under a nitrogen stream, and then heated at 210 ° C. in a nitrogen atmosphere.
For 16 hours. The intrinsic viscosity of the polyester thus obtained was 0.875 dl / g. The stretched film obtained from this polyester has a carbon dioxide gas transmission coefficient of 4.5 cc · mm / m ² · day ·
atm.

[0061]

Comparative Example 1 The polyethylene terephthalate (D-1) obtained in Example 1 was polymerized under the same solid-state polymerization conditions as described above.
Polyethylene terephthalate (D-2) was obtained. The intrinsic viscosity of the polyethylene terephthalate (D-2) thus obtained was 0.820 dl / g.

Next, 50 parts by weight of the obtained polyethylene terephthalate (D-2) and 50 parts by weight of the copolymerized polyester (A-1) were melt-kneaded at a molding temperature of 275 ° C. using a 20 mmφ single screw extruder manufactured by Thermo. And extruded into a strand from the nozzle and cut, 2.5 mm in diameter and 3.5 m in height
m pellets (C-2). The resulting pellet (C-
After preliminarily crystallizing 2) at 170 ° C. for 2 hours under a nitrogen stream, solid phase polymerization was performed at 210 ° C. for 16 hours under a nitrogen atmosphere. The intrinsic viscosity of the polyester thus obtained was 0.840 dl / g. The stretched film obtained from this polyester had a carbon dioxide gas transmission coefficient of 6.1 cc · mm / m ² · day · atm.

[0063]

Comparative Example 2 A stretched film was produced using polyethylene terephthalate (D-2) obtained by polymerizing the polyethylene terephthalate (D-1) obtained in Example 1 under the same solid-state polymerization conditions as above. did. The carbon dioxide permeability coefficient of the stretched film was 16.8 cc · mm / m ² · day · atm.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 5/00 CFD C08K 7/00 4J002 C08K 7/00 B29K 67:00 // B29K 67:00 105: 16 105: 16 B29L 22:00 B29L 22:00 B65D 1/00 A F term (reference) 3E033 AA01 BA17 BA18 BB04 CA03 CA06 CA07 CA16 CA18 FA03 GA02 3E086 AD04 BA04 BA15 BB01 BB85 CA01 DA08 4F071 AA44 AA45 AA05 AB30 AE17 A05 BB06 BB09 BC01 BC04 4F100 AA00A AA00H AB01B AC05 AC10 AK01B AK42A AK42J AL01A AL05A BA01 BA02 BA03 BA04 BA05 BA15 CA23A DA01 DE02A DE02H DG10B EH17A EH20 EH36A EJ38 GB16 J04 A02J01 J02A01 CF061 DJ006 DJ056 FA016 FB086 FD016 GG01

Claims (10)

[Claims] (A) relative to all dicarboxylic acid structural units,
5-85 mol% of the structural unit derived from terephthalic acid, and 15-95 of the structural unit derived from isophthalic acid.
Mol%, and 25 to 100 mol% of a structural unit derived from ethylene glycol, and a structural unit derived from 1,3-bis (2-hydroxyethoxy) benzene, based on all diol structural units. A polyester resin composition (C) comprising a polyester contained in a proportion of 0 to 75 mol% and (B) a layered inorganic filler. 2. 100 parts by weight of the polyester (A),
The polyester resin composition (C) according to claim 1, comprising the layered inorganic filler (B) in an amount of 0.1 to 10 parts by weight. (A) for all dicarboxylic acid structural units,
5-85 mol% of the structural unit derived from terephthalic acid, and 15-95 of the structural unit derived from isophthalic acid.
Mol%, and 25 to 100 mol% of a structural unit derived from ethylene glycol, and a structural unit derived from 1,3-bis (2-hydroxyethoxy) benzene, based on all diol structural units. A polyester resin composition (E) comprising: a polyester contained at a ratio of 0 to 75 mol%; (B) a layered inorganic filler; and (D) polyethylene terephthalate. 4. A molded article comprising the polyester resin composition (E) according to claim 3. 5. A molded article having a multilayer structure, wherein at least one layer is formed from the polyester resin composition (E) according to claim 4. 6. The molded article according to claim 4, wherein the molded article is an injection molded article, a blow molded article, or an extruded molded article. 7. The molded article is a preform.
Or the molded article according to 5. 8. The molded article according to claim 4, wherein the molded article is a biaxially stretched bottle blow-molded from a preform. 9. The molded article according to claim 4, wherein the molded article is an extruded sheet or an extruded film. (A) 5 to 85 mol% of a structural unit derived from terephthalic acid, and 15 to 9 mol% of a structural unit derived from isophthalic acid, based on all dicarboxylic acid structural units.
5 mol%, based on the total diol constitutional unit, 25 to 100 mol% of the constitutional unit derived from ethylene glycol, and the constitutional unit derived from 1,3-bis (2-hydroxyethoxy) benzene Is melt-kneaded with polyester containing (B) a layered inorganic filler and (D) polyethylene terephthalate at a ratio of 0 to 75 mol%, and then the resulting melt-kneaded product is subjected to a polycondensation reaction in a solid phase. The method for producing the polyester composition (E) according to claim 3, characterized in that: