JPH1143588A - Polyester resin composition, preform therefrom and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition that gives molded products, hollow molded vessels and the like having excellent transparency, heat resistance and the like by using a specific polyethylene naphthalate resin and a polyethylene terephthalate resin at a specific ratio. SOLUTION: The objective composition comprises (A) 95-64 wt.% of a linear polyethylene naphthalate resin that has the main recurring units of ethylene 2,6-naphthalenedicarboxylate, and contains >=85 mol.% of 2,6-naphthalene dicarboxylic acid as a dicarboxylic acid component, >=85 mol.% of ethylene glycol and 1.0-5.0 mol.% of diethylene glycol as the glycol components and (B) 5-40 wt.% of a linear polyethylene terephthalate resin that has the main recurring units of ethylene terephthalate, and contains >=85 mol.% of terephthalic acid as a dicarboxylic acid component, >=85 mol.% of ethylene glycol and 1.0-5.0 mol.% of diethylene glycol as the glycol components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a thermoplastic polyester molded article and a hollow molded article which can be advantageously used as containers for foods or beverages having excellent transparency, gas barrier properties, heat resistance and mechanical properties. And a polyester resin composition capable of forming these molded articles.

[0002]

2. Description of the Related Art Polyethylene terephthalate resin is used as a material for containers of carbonated beverages, juices, mineral water, etc. due to its excellent transparency, mechanical strength, heat resistance, gas barrier properties and the like. Have been. However, in recent years, there has been a demand for a material having properties superior to polyethylene terephthalate resin containers in terms of heat resistance, gas barrier properties, and the like. In order to meet such demands, the use of polyethylene naphthalate resin, which has better heat resistance and gas barrier properties than polyethylene terephthalate resin, in containers and the like has been studied.
JP-A-52-45466 describes a hollow container made of polyethylene naphthalate having excellent heat resistance and gas barrier properties. Japanese Patent Application Laid-Open No. 2-217222 discloses a polyethylene naphthalate bottle having a high drawing index of 130 cm or more and a method for producing the same. However, in the case of polyethylene naphthalate resin, molding is difficult and a hollow molded body having excellent transparency and uniform thickness distribution has not been obtained.

Japanese Patent Application Laid-Open No. 64-85732 discloses a 2,6-naphthalene-dicarboxylic acid component of 65 to 98.5.
A heat-resistant bottle made of a polyethylene naphthalate-based copolymer having mol% and 35 to 1.5 mol% of other dicarboxylic acid components (terephthalic acid, isophthalic acid, etc.) and ethylene glycol as a main glycol component is described. I have. However, when the amount of the third component is 10 mol% or more, the melt-polymerized resin does not show a melting point, and the crystallization rate becomes extremely slow, so that crystallization cannot be performed under practical conditions. Rise and acetaldehyde (A
A) Solid-state polymerization for the purpose of reducing the content is impossible. Further, Japanese Patent Application Laid-Open Nos.
JP-A-331255 discloses the use of polyethylene terephthalate resin and polyethylene naphthalate resin mixed with a pre-kneaded product of both, or a melt-kneaded product of both resins, resulting in heat resistance, transparency and gas barrier. It has been shown to provide a composition, container and the like having excellent properties. However,
When such a mixture composition is used, the resulting container has poor heat resistance and transparency, has a high AA content, and can only provide a hollow molded article having a low commercial value. When both of the melt-kneading compositions are used, only a hollow molded article having excellent transparency but having a very high AA content and very poor heat resistance can be obtained. Therefore, as a result of diligent studies on making a hollow molded article or the like having excellent transparency, heat resistance, moldability, gas barrier properties, and the like from a mixture of polyethylene terephthalate resin and polyethylene naphthalate resin, the present invention was concluded. Reached.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a thermoplastic polyester molded article, a hollow molded article, a stretched film, a preformed article relating to these, and the like, which are excellent in heat resistance, gas barrier properties, transparency and mechanical properties. An object of the present invention is to provide a polyester resin composition capable of forming a molded article of the above.

[0005]

In order to achieve the above-mentioned object, the polyester resin composition of the present invention comprises 95 to 60% by weight of a polyethylene naphthalate resin (A) and a polyethylene terephthalate resin (B). In the polyester resin composition comprising 5 to 40% by weight, the polyethylene naphthalate resin (A) has (1) a main repeating unit of ethylene-2,6-naphthalenedicarboxylate, 2) 85 mol% or more of 2,6-naphthalenedicarboxylic acid as a dicarboxylic acid component, and 85 mol% or more of ethylene glycol and 1.0 to 5.0 mol% of diethylene glycol as a (3) glycol component. Including (4)
The sum of the concentration of the terminal methyl ester group and the concentration of the terminal carboxyl group is 30 equivalents / ton or less (hereinafter eq / ton), and (5) the resin (A) has a bulk density of 0.83
0.97 g / cm ^3. The polyethylene terephthalate resin (B) contains (1) a main repeating unit of ethylene terephthalate, and (2) terephthalic acid as a dicarboxylic acid component. (3) Containing at least 85 mol% of ethylene glycol as a glycol component and 1.0 to 5.0 mol% of diethylene glycol, and (4) concentration of terminal methyl ester group and terminal carboxyl group. Is less than 30 eq / ton, and (5)
A linear polyester resin composition, wherein the bulk density of the chip is 0.83 to 0.97 g / cm ³ .

[0006] The polyester resin composition of the present invention having the above constitution provides a molded article or a hollow molded article having excellent transparency, heat resistance, gas barrier properties and mechanical properties.
In the polyester resin composition of the present invention, the polyethylene naphthalate resin (A) constituting the polyester resin composition has an acetaldehyde content of 8 ppm or less and a total content of the cyclic trimer of 0.1 ppm.
40% by weight or less, and the acetaldehyde content of the polyethylene terephthalate resin (B) constituting the polyester resin composition is 10 ppm or less and the total content of cyclic trimers is 0.50% by weight or less. It is a characteristic polyester resin composition. The polyester resin composition of the present invention having the above configuration has excellent transparency, heat resistance,
A molded article or a hollow molded article having gas barrier properties, flavor properties and mechanical properties is provided.

[0007] The preformed article or molded article comprising the polyester resin composition of the present invention is characterized in that (1) the main repeating unit is ethylene-2,6-naphthalenedicarboxy resin;
(2) 85 mol% or more of 2,6-naphthalenedicarboxylic acid as a dicarboxylic acid component, and (3) 85 mol% or more of ethylene glycol and 1.0 g of diethylene glycol as a glycol component. (4) the total of the terminal methyl ester group concentration and the terminal carboxyl group concentration is 30 eq / ton or less;
The bulk density of the resin (A) chip is 0.83 to 0.97.
g / cm ³ of polyethylene naphthalate resin (A)
95 to 60% by weight, (1) a main repeating unit is ethylene terephthalate, (2) terephthalic acid is 85 mol% or more as a dicarboxylic acid component, and (3) glyco-
85% by mole or more of ethylene glycol and 1.0 to 5.0% by mole of diethylene glycol as
(4) The total of the terminal methyl ester group concentration and the terminal carboxyl group concentration is 30 eq / ton or less, and (5) the bulk density of the resin (B) chip is 0.83 to 0.97 g / ton.
cm ³ polyethylene terephthalate resin (B) 1
The resin composition forming the preformed article or the molded article satisfies the following conditions (a) to (4): And a polyester resin preform or molded article. B) When the crystallization peak temperature (Tc1) of the preformed body or the unstretched part is 165 ° C. or more, which is measured by a differential scanning calorimeter (DSC) at a heating rate of 1 ° C./min. is there. B) The weight percentage (BLD%) of the Tc1 and the polyethylene naphthalate resin (A) in the preform or molded product
Is 0.60 (BLD%) + 120.0 ≦ Tc
1 ≦ 0.60 (BLD%) + 155.0. C) The melting point (Tm) of the preformed body or the unstretched part of the preformed body or unstretched part measured by a differential scanning calorimeter (DSC) at a heating rate of 1 ° C./min and the polyethylene naphthalate in the preformed body or the formed body. Weight percentage of resin (A) (BLD%)
Is 0.87 (BLD%) + 178.0 ≦ Tm
≦ 0.87 (BLD%) + 193.0. D) For the unstretched part of the preformed body or the molded body, the heat of crystallization at the time of heating (Qc) and the heat of crystal melting (Qm) measured by a differential scanning calorimeter (DSC) at a heating rate of 1 ° C./min.
Is 15 mj / mg or more and 20 mj / mg or more, respectively. The preformed article or molded article of the present invention having the above configuration,
Has excellent transparency, heat resistance, gas barrier properties and mechanical properties.

The polyester resin preform or molded article of the present invention has an acetaldehyde content of 8 ppm.
The polyethylene naphthalate resin (A) having a total content of the cyclic trimer of 0.40% by weight or less and the acetaldehyde content of 10 ppm or less, and the cyclic trimer having a total content of 0.50% by weight or less. It is obtained by melt-molding the above-mentioned polyester resin composition composed of the above-mentioned polyethylene terephthalate resin (B), and the characteristics of the resin composition forming the pre-molded article or the molded article are as follows. The present invention is characterized by satisfying the above conditions a) to d). The preformed article or molded article of the present invention having the above-described structure has excellent heat resistance, gas barrier properties, mechanical properties, and further excellent transparency and flavor. Further, the polyester resin preform of the present invention preferably has a total content of cyclic trimers of 0.50% by weight or less. The polyester resin preform of the present invention having the above-described structure provides a molded article or a hollow molded article having excellent heat resistance, gas barrier properties, mechanical properties, and further excellent transparency.

The polyester resin hollow molded article of the present invention is a hollow molded article obtained by stretch blow molding the above preformed article, and the composition for forming the hollow molded article has the following characteristics. ) To ヌ). E) Regarding the plug of the hollow molded body, use a differential scanning calorimeter (D
SC), the crystallization peak temperature (Tc1) at the time of heating measured at a heating rate of 1 ° C./min is 165 ° C. or more. F) The relationship between the Tc1 and the weight percentage (BLD%) of the polyethylene naphthalate resin (A) in the hollow molded article is as follows:
0.60 (BLD%) + 120.0 ≦ Tc1 ≦ 0.60
(BLD%) + 155.0. G) For the plug portion of the hollow molded body, use a differential scanning calorimeter (D
SC) at a heating rate of 1 ° C./min.
m) and the weight percentage (BLD%) of the polyethylene naphthalate resin (A) in the hollow molded article is 0.87.
(BLD%) + 178.0 ≦ Tm ≦ 0.87 (BLD
%) + 193.0. H) The differential scanning calorimeter (D)
SC) and the heat of crystallization (Qc) and the heat of crystal fusion (Qm) measured at a heating rate of 1 ° C./min.
It is 15 mj / mg or more and 20 mj / mg or more. Li) The acetaldehyde content is 50 ppm or less. Nu) The haze is 8% or less. The hollow molded article of the present invention having the above structure has excellent transparency, heat resistance, gas barrier properties and mechanical properties.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The polyethylene naphthalate resin (A) used in the present invention comprises (1) a polymer wherein the main repeating unit is ethylene-
2,6-naphthalenedicarboxylate,
(2) 2,6-naphthalenedicarboxylic acid as a dicarboxylic acid component is at least 85 mol%, preferably at least 87 mol%, more preferably at least 90 mol%, and (3) glyco-
85 mol% or more, preferably 87 mol% or more, more preferably 90 mol% of ethylene glycol as a toluene component
Above, and a linear polyester containing 1.0 to 5.0 mol%, preferably 1.3 to 4.5 mol%, more preferably 1.5 to 4.0 mol% of diethylene glycol (hereinafter, DEG). Resin. When the ethylene-2,6-naphthalenedicarboxylate unit is 85 mol% or less, the resin is easily fused in a drying step or a solid phase polymerization step, and the heat resistance of the obtained molded article or the like is low. Very bad. Also DE
When the G content is 1.0 mol% or less, the transparency of the obtained molded article or hollow molded article becomes extremely poor, and when the G content is 5.0 mol% or more, the heat resistance of the obtained molded article or the like becomes poor. And the AA content of the molded article or the like is greatly increased, which adversely affects the taste of the contents. That is, polyethylene naphtha
It was found that the DEG content of the resin (A) had a very large effect on the physical properties of the molded article of the present invention.

The dicarboxylic acid used for copolymerization of the polyethylene naphthalate resin (A) in the present invention includes terephthalic acid, isophthalic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxy acid Aromatic dicarboxylic acids such as ethanedicarboxylic acid and functional derivatives thereof,
Oxy acids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, adipic acid, sebacic acid, succinic acid, aliphatic dicarboxylic acids such as glutaric acid and their functional derivatives, alicyclic groups such as cyclohexanedicarboxylic acid And dicarboxylic acids and functional derivatives thereof. Glycols used for copolymerization include aliphatic glycols such as trimethylene glycol, tetramethylene glycol and neopentyl glycol, and alicyclic glycols such as cyclohexanedimethanol. And aromatic glycols such as bisphenol A and alkylene oxide adducts of bisphenol A.

Further, other copolymerizable components comprising a polyfunctional compound in the polyethylene naphthalate resin (A) include trimellitic acid and pyromellitic acid as acid components. Glycerin and pentaerythritol can be mentioned as components. The amount of the above-mentioned copolymer component to be used must be such that the polyethylene naphthalate resin (A) substantially maintains a linear shape.

The above polyethylene naphthalate resin (A) can be produced by a conventionally known production method. That is, 2,6-naphthalenedicarboxylic acid and ethylene glycol and / or a third component are directly reacted to distill water and esterify, followed by polycondensation under reduced pressure, or Dimethyl-2,6-naphthalenedicarboxylate and ethylene glycol and / or a third component are reacted to distill off methyl alcohol and transesterify, followed by polycondensation under reduced pressure. Manufactured by an exchange method. Further increase the intrinsic viscosity, A
Solid state polymerization may be performed to reduce the A content.

When the polyethylene naphthalate resin (A) used in the present invention is produced by a transesterification method, a metal carboxylate compound such as Mg, Mn, Ca, Zn or the like is used as a transesterification catalyst; Ge, S as catalyst
Compounds such as b and Ti are used. Further, in order to eliminate the activity of the transesterification catalyst, a phosphorus compound such as phosphoric acid or trimethyl phosphate can be added after completion of the transesterification reaction. In the case of the direct esterification method, a compound of Ge, Sb, and Ti is used as a polycondensation catalyst.
In order to control the DEG content, a basic compound such as a tertiary amine such as triethylamine or tri-n-butylamine, or a quaternary ammonium salt such as tetraethylammonium hydroxide can be added to the esterification step.

The intrinsic viscosity of the polyethylene naphthalate resin (A) used in the present invention is 0.40 to 0.90 dl /.
g is preferably in the range of 0.45 to 0.87 dl / g, more preferably 0.50 to 0.85 dl / g. 0.
If it is less than 40 dl / g, the mechanical properties of the obtained molded article and the like are poor. On the other hand, when it exceeds 0.90 dl / g, the temperature of the resin becomes high at the time of melting by a molding machine or the like, so that thermal decomposition becomes severe, and problems such as coloring of the molded body to yellow occur.

The polyethylene naphthalate resin (A) used in the present invention has a terminal methyl ester group concentration and a terminal carboxyl group concentration of 30 eq / ton or less, preferably 28 eq / ton or less, more preferably 25 eq / ton or less.
on or less. When the total concentration of the terminal methyl ester group and the terminal carboxyl group is 30 eq / ton or more, the compatibility between the polyethylene naphthalate resin (A) and the polyethylene terephthalate resin (B) is deteriorated, and thus the obtained resin is obtained. The transparency of a molded article or the like becomes very poor.

The bulk density of the chips of the polyethylene naphthalate resin (A) used in the present invention is 0.83 to 0.9.
7 g / cm ³ , preferably 0.84 to 0.96 g / cm
³ , more preferably 0.85 to 0.95 g / cm ³ . For example, when the chip size is very large or when fine chips or powders are mixed in a large amount, the bulk density becomes small. Bulk density is 0.83 g / cm ³
If the particle size is smaller, the fluidity of the chips in the injection molding machine deteriorates, and the chips do not melt in a uniform state, or are uniformly melt-mixed or compatibilized with the polyethylene terephthalate resin (B) to be mixed. Becomes difficult. As a result, the transparency of the molded article or the like becomes very poor. In the case of solid-phase polymerized resin, when the chip size is large, or when the bulk density is small due to the inclusion of a large amount of fine chips or powder, the density difference between the chips becomes very large. In addition, the molecular weight distribution of the polyethylene naphthalate resin (A) becomes very wide. In such a case, the molten state of the polyethylene naphthalate resin (A) in the injection molding machine becomes more non-uniform, and the polyethylene naphthalate resin (B) is uniformly mixed and compatibilized with the polyethylene terephthalate resin (B) to be mixed. Becomes very difficult. As a result, the transparency of the molded article and the like is further deteriorated.
When the bulk density is 0.97 g / cm ³ or more, the filling in the injection molding machine becomes very good, so that the heat generation in the molding machine increases, and as a result, the acetaldehyde content of the molded body becomes 50 ppm or more. This is problematic in terms of the flavor of the product. In order to obtain a molded article having excellent transparency, the ratio of the bulk density of the polyethylene naphthalate resin (A) to the bulk density of the polyethylene terephthalate resin (B) should be 0.8 to 1%. 0.2, preferably 0.85 to 1.15, and more preferably 0.9 to 1.1. If the ratio of the bulk densities of the two is 0.8 or less, or 1.2 or more, the mixing ratio fluctuates when both mixed resins are sent to a hopper or the like of a molding machine. The blending ratio of both resins changes, causing a problem.

The polyethylene naphthalate resin (A) used in the present invention has an acetaldehyde content of 8 ppm or less, preferably 7 ppm or less, more preferably 4 pp.
m or less. When the acetaldehyde content is 8 ppm or more, the obtained molded article or the like has an acetaldehyde content of 5 ppm.
The content is as high as 0 ppm or more, which adversely affects the taste and odor of the contents such as the molded body.

The total content of the cyclic trimer of the polyethylene naphthalate resin (A) used in the present invention is 0.40% by weight or less, preferably 0.35% by weight or less, more preferably 0.30% by weight or less. % By weight or less. When heat treatment is performed in a heating mold at the time of molding to impart high heat resistance to the molded article or the hollow molded article, when the total content of the cyclic trimer is 0.50% by weight or more, Transparency of the resulting hollow molded article or the like becomes extremely poor due to a sudden increase in oligomer adhesion. Here, the term "cyclic trimer" refers to both a cyclic trimer composed of ethylene terephthalate units and a cyclic trimer composed of ethylene naphthalate units. The sum of the contents of the two is the “total content”.

The polyethylene terephthalate resin (B) used in the present invention has (1) a main repeating unit of ethylene terephthalate, and (2) terephthalic acid as a dicarboxylic acid component in an amount of at least 85 mol%. Preferably 87
Mol% or more, more preferably 90 mol% or more, (3)
85 mol% of ethylene glycol as a glycol component
Or more, preferably 87 mol% or more, more preferably 9 mol% or more.
0 mol% or more, and DEG is 1.0 to 5.0 mol%,
Preferably, it is a linear polyester resin containing 1.3 to 4.5 mol%, more preferably 1.5 to 4.0 mol%. When the ethylene terephthalate unit is 85 mol% or less, the resin is easily fused in a drying step or a solid-phase polymerization step, and the heat resistance of the obtained molded article or the like becomes extremely poor. When the DEG content is 1.0 mol% or less, the transparency of the obtained molded article or hollow molded article becomes extremely poor. When the DEG content is 5.0 mol% or more, the heat resistance of the obtained molded article or the like becomes high. Thus, the AA content of the molded article or the like becomes extremely high, which adversely affects the taste of the contents. That is, it was found that the DEG content of the polyethylene terephthalate resin (B) had a very large effect on the physical properties of the molded article of the present invention.

The dicarboxylic acid used in the copolymerization of the polyethylene terephthalate resin (B) in the present invention includes isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4'- Aromatic dicarboxylic acids such as dicarboxylic acid and diphenoxyethane dicarboxylic acid and functional derivatives thereof, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, adipic acid, sebacic acid, succinic acid, and glutaric acid And their functional derivatives, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and their functional derivatives.

Glycols used for copolymerization include trimethylene glycol and tetramethylene glycol.
, An aliphatic glycol such as neopentyl glycol, an alicyclic glycol such as cyclohexanedimethanol, an aromatic glycol such as bisphenol A or an alkylene oxide adduct of bisphenol A. And the like.

Further, other copolymerizable components comprising a polyfunctional compound in the polyethylene terephthalate resin (B) include trimellitic acid and pyromellitic acid as acid components. Glycerin and pentaerythritol can be mentioned as components.
The amount of the above-mentioned copolymer component to be used must be such that the polyethylene terephthalate resin (B) substantially maintains a linear shape. The above polyethylene terephthalate resin (B) can be produced by a conventionally known production method. That is, terephthalic acid is directly reacted with ethylene glycol and / or the third component to remove water and esterify, followed by polycondensation under reduced pressure, or by direct esterification with dimethyl terephthalate. It is produced by a transesterification method in which ethylene glycol and / or a third component are reacted to remove methyl alcohol and transesterify, followed by polycondensation under reduced pressure. Further increase the intrinsic viscosity,
Solid state polymerization may be performed to reduce the AA content.

The catalyst used in producing the polyethylene terephthalate resin (B) used in the present invention is the same as the catalyst used in producing the polyethylene naphthalate resin (A). You can do it. The intrinsic viscosity of the polyethylene terephthalate resin (B) used in the present invention is from 0.60 to 1.30 dl / g, preferably from 0.65 to 1.30 dl / g.
1.20 dl / g, more preferably 0.70 to 0.9
The range is 0 dl / g. At 0.60 dl / g or less,
The mechanical properties of the obtained molded article are poor. Also, 1.30
If the dl / g exceeds dl / g, the resin temperature rises during melting by a molding machine or the like, and thermal decomposition becomes severe, which causes problems such as the molded product being colored yellow.

The total of the terminal methyl ester group concentration and the terminal carboxyl group concentration of the polyethylene terephthalate resin (B) used in the present invention is 30 eq / ton or less, preferably 28 eq / ton or less, more preferably 26 eq / ton or less.
q / ton or less. If the total of the terminal methyl ester group concentration and the terminal carboxyl group concentration is 30 eq / ton or more, the compatibility between the polyethylene naphthalate resin (A) and the polyethylene terephthalate resin (B) becomes poor, and therefore, the The transparency of the molded article or the like deteriorates.

The polyethylene terephthalate resin (B) used in the present invention has a chip having a bulk density of 0.83 to 0.5.
97 g / cm ³ , preferably 0.84 to 0.96 g / c
m ³ , more preferably 0.85 to 0.95 g / cm. For example, when the chip size is very large or when fine chips or powders are mixed in a large amount, the bulk density becomes small. Bulk density is 0.83 g / cm ³
If the particle size is smaller, the fluidity of the chips in the injection molding machine deteriorates, and the chips are not melted in a uniform state, or are uniformly melt-mixed and compatibilized with the polyethylene naphthalate resin (A) to be mixed. Becomes difficult. As a result, the transparency of the molded article or the like becomes very poor.

In the case of solid-phase polymerized resin, when the chip size is large, or when the bulk density is small due to the inclusion of a large amount of fine chips or powder, the density difference between the chips is very small. The molecular weight distribution of the polyethylene terephthalate resin (B) becomes very wide.
In such a case, the molten state of the polyethylene terephthalate resin (B) in the injection molding machine becomes more uneven,
In addition, polyethylene naphthalate resin fat (A) to be mixed with
And it becomes very difficult to uniformly mix and compatibilize the same. as a result,
The transparency of the molded article and the like is further deteriorated. When the bulk density is 0.97 g / cm ³ or more, the filling in the injection molding machine becomes very good, so that the heat generated in the molding machine increases, and as a result, the acetaldehyde content of the molded article becomes 50 pp.
m or more, which is problematic in terms of the flavor of the contents.

The polyethylene terephthalate resin (B) used in the present invention has an acetaldehyde content of 10 pp.
m or less, preferably 6 ppm or less, more preferably 4 ppm or less.
ppm or less. When the acetaldehyde content is 8 ppm or more, the acetaldehyde content of the obtained molded article or the like becomes as high as 50 ppm or more, which adversely affects the taste or smell of the contents of the molded article or the like.

The total content of the cyclic trimer of the polyethylene terephthalate resin (B) used in the present invention is 0.50
% By weight, preferably 0.40% by weight or less, more preferably 0.35% by weight or less. When heat treatment is performed in a heating mold at the time of molding to impart heat resistance to the molded article or the hollow molded article, when the total content of the cyclic trimer is 0.50% by weight or more, Transparency of the resulting hollow molded article or the like becomes extremely poor due to a sudden increase in oligomer adhesion. Here, the “cyclic trimer” and the “total content” thereof are as described above.

The preformed article, molded article and hollow molded article of the present invention are polyethylene naphthalate resin (A) 95-60.
% By weight, preferably 93 to 65% by weight, more preferably 90 to 70% by weight, polyethylene terephthalate resin (B) 5 to 40% by weight, preferably 7 to 35% by weight,
More preferably, it is composed of 10 to 30% by weight.
When the content of the polyethylene naphthalate resin (A) in the preform or the hollow molded body exceeds 95% by weight, the moldability and stretchability are poor, and the transparency of the obtained preform or the hollow molded body is poor. become worse. On the other hand, if the content of the polyethylene naphthalate resin (A) is less than 60% by weight, the obtained hollow molded article will have poor ultraviolet shielding properties and gas barrier properties. The polyester resin preform, molded article and hollow molded article of the present invention were further examined for thermal properties measured by a differential scanning calorimeter (DSC) and properties such as transparency and heat resistance of the molded article. It has been found that there is a relationship between the thermal characteristics (at a heating rate of 1 ° C./min) by a scanning calorimeter (DSC) and the characteristics such as transparency and heat resistance of a molded article.

The crystallization peak at the time of heating, which was measured by a differential scanning calorimeter (DSC) at a temperature rising rate of 1 ° C./min with respect to the unstretched portion of the preformed article or the molded article of the present invention or the plug portion of the hollow molded article. The temperature (Tc1) is 165 ° C. or lower, and the relationship with the weight percentage (BLD%) of the polyethylene naphthalate resin (A) in the molded article or the hollow molded article is expressed by the following formula 0.60 (BL)
D%) + 120.0 ≦ Tc1 ≦ 0.60 (BLD%) +
155.0 needs to be satisfied, and preferably,
The following formula: 0.60 (BLD%) + 125.0 ≤ Tc1 ≤
It is necessary to satisfy 0.60 (BLD%) + 150.0.

When the crystallization peak temperature (Tc1) of the unstretched portion of the molded article or the plug of the hollow molded article at the time of heating is higher than the upper limit of the above formula, the obtained molded article or the like may be used. The heat resistance and gas barrier properties are deteriorated, and the thickness distribution, mechanical properties, etc. are also deteriorated. In addition, the crystallization peak temperature (Tc
When 1) is a temperature lower than the lower limit of the above formula, the transparency of the obtained molded article or the like is extremely lowered, and the thickness distribution is also deteriorated.

The melting point (Tm) of the unstretched part of the preformed article or the molded article of the present invention or the plug of the hollow molded article measured by a differential scanning calorimeter (DSC) at a heating rate of 1 ° C./min. Polyethylene naphthalate resin (A)
Is expressed by the following formula: 0.87
(BLD%) + 178.0 ≦ Tm ≦ 0.87 (BLD
%) + 193.0, preferably 0.87 (BLD%) + 180.0 ≦ Tm
It is necessary to satisfy ≦ 0.87 (BLD%) + 190.0.

When the melting point (Tm) of the unstretched portion of the molded article or the plug of the hollow molded article is lower than the lower limit of the above formula, the heat resistance and gas barrier properties of the obtained molded article are poor. In addition, the wall thickness distribution, mechanical characteristics, and the like also deteriorate. Further, when the melting point (Tm) is a temperature not lower than the upper limit of the above formula, the transparency of the obtained molded article or the like is extremely lowered, and the thickness distribution is also deteriorated.

In addition, the crystallization exotherm (Qc) of the unstretched portion of the molded article of the present invention and the plug of the hollow molded article measured at a temperature increasing rate of 1 ° C./min with a differential scanning calorimeter (DSC). ) And heat of crystal melting (Qm) are 15 mj / mg, respectively.
Or more, preferably 17 mj / mg, more preferably 20 mj / mg.
mj / mg or more, and 20 mj / mg or more, preferably 23 mj / mg or more, and more preferably 25 mj / mg.
It is necessary to be above.

The heat of crystallization (Qc) and the heat of crystallization (Qm) at the time of temperature rise of the unstretched portion of the molded article and the plug of the hollow molded article are respectively 15 mj / mg or less, and
When the content is 20 mj / mg or less, the heat resistance, gas barrier properties, mechanical properties, etc. of the obtained molded article or hollow molded article are deteriorated.

The total content of the cyclic trimer in the polyester resin preform of the present invention is 0.50% by weight or less, preferably 0.45% by weight or less, more preferably 0.40% by weight or less. When performing heat treatment in a heating mold at the time of molding to give heat resistance to the molded article or the hollow molded article, when the total content of the cyclic trimer is 0.50% by weight or more,
The adhesion of the oligomer to the mold surface is rapidly increased, and the transparency of the obtained hollow molded article or the like becomes extremely poor. Here, the “cyclic trimer” and the “total content” thereof are as described above.

The acetaldehyde content of the hollow molded article of the present invention is 50 ppm or less, preferably 30 ppm or less, more preferably 20 ppm or less. When the acetaldehyde content is 50 ppm or more, the acetaldehyde odor is transferred to the contents, which is particularly problematic for beverages.

The haze of the hollow molded article of the present invention is 8% or less,
It is preferably at most 5%, more preferably at most 3%. When the haze is 8% or more, the hollow molded article exhibits a cloudy pearly luster and loses commercial value. The polyester resin stretched film of the present invention can be obtained by stretching the unstretched sheet, which is the preformed body, in at least one direction by using any conventionally known method. In the case of biaxial stretching, either a simultaneous biaxial stretching method or a sequential biaxial stretching method may be used. The stretching ratio in the longitudinal direction and / or the width direction of the film can be arbitrarily set according to the purpose.

The preformed article in the present invention is not limited to a preformed article for a hollow molded article, but also includes extruded sheets, pipes, cylinders, etc., and includes polyethylene naphthalate. Melt viscosity of resin (A) and polyethylene terephthalate resin (B), difference in melt viscosity between both resins, temperature at the time of injection of preform, melting time, back pressure, and
It can be obtained by appropriately controlling the screw rotation speed and the like. The heat stabilizer, thermal oxidation stabilizer, antistatic agent, weathering stabilizer, lubricant, pigment, dye, pigment dispersant or the molded article defective article of the present invention at the time of molding the preformed article of the present invention, etc. It can be added in a range that does not impair the purpose.

Various known methods can be used for uniformly mixing the polyethylene naphthalate resin (A) and the polyethylene terephthalate resin (B) of the present invention. For example, a double cone blender, A method using a ribbon blender or the like can be applied. Further, both resins mixed by such a method can be melt-kneaded and granulated by a single-screw extruder, a twin-screw extruder, a vented extruder or the like. The preform of the present invention is produced by, for example, uniformly mixing the polyethylene naphthalate resin (A) and the polyethylene terephthalate resin (B) having the above-mentioned properties, and then directly injection molding. Can be done.

The hollow molded article of the present invention is a two-step method (cold parison method) in which a bottomed preform (parison) molded by a known injection molding machine or the like is stretch-blown by a stretch blow molding machine. Or a one-step method (hot parison method) in which molding of a preform and stretching blow molding are performed by the same machine, a direct blow molding method,
It can be manufactured by an extrusion blow molding method. Further, in order to reduce the AA content of the hollow molded article, it is preferable to use a vent type injection molding machine. When the preform is a sheet, pipe, tube, or the like, the preform can be appropriately formed into a container, a package, or the like by compression molding, vacuum molding, or the like.

[0043]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. The method for measuring the main characteristic values will be described below. (1) Intrinsic viscosity (IV) of polyethylene terephthalate resin (B) (hereinafter referred to as “PET resin”) 1,1,2,2-tetrachloroethane / phenol (2)
/ 3 weight ratio) It was determined from the solution viscosity at 30 ° C in a mixed solvent. (2) Polyethylene naphthalate resin (A) (hereinafter referred to as "P
EN resin ") was determined from the solution viscosity at 30 ° C in a mixed solvent of 1,1,2,2-tetrachloroethane / p-chlorophenol (1/3 weight ratio).

(3) Bound diethylene glycol content (DEG content) in the resin Decomposed with methanol, the amount of DEG was determined by gas chromatography, and expressed as a ratio (mol%) to the total glycol component. (4) Terminal methyl ester group concentration (hereinafter referred to as "MTV") Calculated by quantifying methyl alcohol decomposed by monoethanolamine and produced by gas chromatography (equivalent / one ton of resin).

(5) Terminal carboxyl group concentration (hereinafter referred to as “A
V ") Analytical Chemistry Vol. 26, p. 1614 (1954)
Year) according to the method of Phol (equivalents / ton of resin). (6) Acetaldehyde content (AA) A 2 to 3 mm square sample from a resin pellet or a container cap and a sample / distilled water = 1 g / 2 ml of distilled water are put into a nitrogen-purged glass ampule and the upper part is melted. Sealed, 160 ℃
For 2 hours, and after cooling, acetaldehyde in the extract was measured by high-sensitivity gas chromatography, and the concentration was indicated in ppm.

(7) Total content of PET resin cyclic trimer (hereinafter referred to as “PET-CT”) A sample is dissolved in a mixed solution of hexafluoroisopropanol / chloroform, and further diluted with chloroform. After adding methanol to precipitate a polymer, the mixture is filtered. The filtrate is evaporated to dryness, made up to a constant volume with dimethylformamide, and subjected to liquid chromatography to obtain a cyclic trimer composed of ethylene terephthalate units and a cyclic trimer composed of ethylene naphthalate units. Quantified. (8) The total content of the cyclic trimer of the PEN resin (hereinafter referred to as “PE
N-CT ") by the same method as for PET resin. (9) The total content of the cyclic trimer of the preform (hereinafter referred to as “C
T ") by the same method as the PET resin.

(10) Density of molded product, etc. 25 using a density gradient tube of a mixed solvent of carbon tetrachloride / n-heptane.
Measured in ° C. (11) Bulk density (hereinafter referred to as “BD”) Measured by a method according to JIS K6721. (12) Haze (% haze) A sample was cut out from the body (thickness: about 0.4 mm) of the molded bottle, and the haze was measured with a haze meter manufactured by Toyo Seiki Seisaku-sho.

(13) DSC measurement (Tc1, Tm, Q
c, Qm) The differential molded calorimeter RDC-220 manufactured by Seiko-Electronic Industry Co., Ltd. was measured for the pre-formed body and the measurement sample from the top surface of the plug part of the formed body. The amount of the sample was 4.0 mg, and the heating rate was measured at 1 ° C / min. (14) Heat resistance The formed hollow molded body is filled with boiling water and then capped and left for 5 minutes. Thereafter, after cooling with water at 10 ° C., the water was drawn in, and the shrinkage was determined from the change in the mesh size.

Examples 1 to 3 and Comparative Examples 1 to 3 1) PEN resin PEN resin (No. 1) was prepared from dimethyl-2,6-naphthalenedicarboxylate and ethylene glycol. No.2, No.3, No.4)
Is dimethyl-2,6-naphthalenedicarboxylate
Dimethyl terephthalate and ethylene glycol by a conventional method. In addition, PEN resin (No.
5) is dimethyl-2,6-naphthalenedicarboxyle
, Ethylene glycol and dithylene glycol by a conventional method. Table 1 shows the characteristics of the resin.

2) PET resin PET resin (No. 9) is made of dimethyl terephthalate and ethylene glycol, and PET resin (No. 10).
Was prepared from dimethyl terephthalate, ethylene glycol and diethylene glycol by a conventional method. PET
Resins (No. 6, No. 7, No. 8) were produced from dimethyl terephthalate, dimethyl-2,6-naphthalenedicarboxylate and ethylene glycol by a conventional method. Table 2 shows the properties of the resin.

3) Molding of Hollow Molded Article Using the above PET resin and PEN resin, a pre-molded article was molded by an M-100 injection molding machine manufactured by Meiki Seisakusho. Next, this preform was used for LB- manufactured by CORPOPLAST.
It was biaxially stretched and blown with a 01E molding machine to prepare a 500 ml container. Table 3 shows the physical properties of the obtained container together with Comparative Examples. Among these Comparative Examples, Comparative Examples 1 and 2 were PEN
The molten state of the resin and the PET resin is very poor, and the resulting hollow container has a streak-like portion with poor transparency, and the thickness unevenness of the container wall is large. As is clear from the results in Table 3, the hollow molded container of the present invention shows excellent transparency and heat resistance.

Example 4 and Comparative Example 4 1) PEN resin PEN resins (No. 10) and (No. 11) were obtained by direct esterification of naphthalene-2,6-dicarboxylic acid, terephthalic acid and ethylene glycol. Then, a chip of a melt-polymerized polymer polycondensed in the presence of a germanium dioxide catalyst was produced by solid-phase polymerization. Table 4 shows the properties of the resin.

2) PET Resin PET resins (No. 12) and (No. 13) are melt-polymerized by direct esterification reaction of terephthalic acid and ethylene glycol and then polycondensation in the presence of a germanium dioxide catalyst. Polymer chips were produced by solid phase polymerization. Table 5 shows the properties of the resin.

3) Molding of Hollow Molded Article A pre-molded article was molded from the above PET resin and PEN resin using an M-100 injection molding machine manufactured by Meiki Seisakusho. Next, this preform was used for LB- manufactured by CORPOPLAST.
01E molding machine for biaxial stretching blow, then about 160 ° C
Was heat-fixed in a mold set to prepare a 500 ml container. Table 6 shows the physical properties of the obtained container together with Comparative Examples. As is clear from the results in Table 6, the hollow molded container of the present invention shows excellent transparency and heat resistance, and has a low AA content. Also, no mold contamination was observed.

Example 5 and Comparative Example 5 1) PEN resin PEN resins (No. 1) and (No. 11) were used. 2) PET resin PET resins (No. 6) and (No. 13) were used.

3) Preparation of Unstretched Sheet Using the above PET resin and PEN resin, a 40 mm
An unstretched sheet having a thickness of 0.5 mm was produced by the twin screw extruder. Table 7 shows the sheet properties and the like. As is clear from the results in Table 7, the unstretched sheet of the present invention shows excellent physical properties.
A container having a depth of 20 mm was prepared from the sheet using a vacuum forming machine, and left in an oven at about 70 ° for 10 minutes to examine heat resistance. As shown in Table 7, the heat resistance of the container from the sheet of the present invention is good.

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[Table 1]

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

[Table 4]

[0061]

[Table 5]

[0062]

[Table 6]

[0063]

[Table 7]

[0064]

The polyester resin composition according to the present invention,
The preformed article or the molded article and the hollow molded article can provide a container or a package excellent in transparency, heat resistance, and mechanical properties.

Claims (5)

[Claims] 1. A polyethylene naphthalate resin (A) 9
A polyester resin composition comprising 5 to 60% by weight and 5 to 40% by weight of a polyethylene terephthalate resin (B), wherein the polyethylene naphthalate resin (A)
Has (1) a main repeating unit of ethylene-2,6-naphthalenedicarboxylate, and (2) 2,6-naphthalenedicarboxylic acid as a dicarboxylic acid component.
(3) Containing at least 85 mol% of ethylene glycol as a glycol component and 1.0 to 5.0 mol% of diethylene glycol, and (4) concentration of terminal methyl ester group and terminal carboxyl group. (5) the resin (A) has a chip bulk density of 0.83 to 0.97 g / cm ³ , and the polyethylene terephthalate resin (B) (1) the main repeating unit is ethylene terephthalate, and (2) terephthalic acid as a dicarboxylic acid component is 85 mol% or more;
(3) 85 ethylene glycol as a glycol component
Mol% or more and diethylene glycol in an amount of 1.0 to 5.
0 mol%, (4) the total of the terminal methyl ester group concentration and the terminal carboxyl group concentration is 30 equivalents / ton or less, and (5) the bulk density of the resin (B) chip is 0.83
A polyester resin composition having a weight of 0.97 g / cm ³ to 0.97 g / cm ³ . 2. The polyethylene naphthalate resin (A) has an acetaldehyde content of 8 ppm or less and a cyclic 3
The total content of the monomer is 0.40% by weight or less, the acetaldehyde content of the polyethylene terephthalate resin (B) is 10 ppm or less, and the total content of the cyclic trimer is 0.50% by weight.
The polyester resin composition according to claim 1, wherein the amount is not more than weight%. 3. A preformed article or molded article comprising the resin composition according to claim 1 or 2, wherein the resin composition forming the preformed article or molded article has the following properties a).
A polyester resin preform or molded product, which satisfies the conditions of (1) to (4). B) When the crystallization peak temperature (Tc1) of the preformed body or the unstretched part is 165 ° C. or more, which is measured by a differential scanning calorimeter (DSC) at a heating rate of 1 ° C./min. is there. B) The weight percentage (BLD%) of the Tc1 and the polyethylene naphthalate resin (A) in the preform or molded product
0.60 (BLD%) + 120.0 ≦ Tc1 ≦ 0.60
(BLD%) + 155.0. C) The melting point (Tm) of the preformed body or the unstretched portion of the preformed body or unstretched part measured at a heating rate of 1 ° C./min with a differential scanning calorimeter (DSC) and the polyethylene naphthalate in the preformed body or the formed body. The relationship with the weight percentage (BLD%) of the resin (A) is 0.87 (BLD%) + 178.0 ≦ Tm ≦ 0.87
(BLD%) + 193.0. D) For the unstretched part of the preformed body or the molded body, the heat of crystallization at the time of heating (Qc) and the heat of crystal melting (Qm) measured by a differential scanning calorimeter (DSC) at a heating rate of 1 ° C./min.
Is 15 mj / mg or more and 20 mj / mg or more, respectively. 4. A preform according to claim 3, wherein said preform is stretch blown.
A hollow molded article obtained by molding, wherein the properties of a composition forming the hollow molded article satisfy the following conditions (e) to (v). E) Regarding the plug of the hollow molded body, use a differential scanning calorimeter (D
SC), the crystallization peak temperature (Tc1) at the time of heating measured at a heating rate of 1 ° C./min is 165 ° C. or more. F) The relationship between the Tc1 and the weight percentage (BLD%) of the polyethylene naphthalate resin (A) in the hollow molded article is 0.60 (BLD%) + 120.0 ≦ Tc1 ≦ 0.60
(BLD%) + 155.0. G) For the plug portion of the hollow molded body, use a differential scanning calorimeter (D
SC) at a heating rate of 1 ° C./min.
m) and the weight percentage (BLD%) of the polyethylene naphthalate resin (A) in the hollow molded article is 0.87 (BLD%) + 178.0 ≦ Tm ≦ 0.87
(BLD%) + 193.0. H) The differential scanning calorimeter (D)
SC) and the heat of crystallization (Qc) and the heat of crystal fusion (Qm) measured at a heating rate of 1 ° C./min.
5 mj / mg or more and 20 mj / mg or more. I) The acetaldehyde content is 50 ppm or less. D) Haze is 8% or less. 5. A polyester stretched film, wherein the polyester resin preform according to claim 3 is stretched and oriented in at least one direction.