JP2003201390A - Polyester hollow molded body - Google Patents

Abstract

(57) [Problem] To provide a high-quality polyester hollow molded article having excellent heat resistance, drop strength, transparency, and ultraviolet blocking properties, and particularly suitable as a container for beverages and foods. SOLUTION: The polyester (A) and the polyimide (B) are contained, and the number of coarse foreign substances of 10 μm or more is 100 / g.
A polyester hollow molded article having a total amount of metal elements of 3 to 450 ppm below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester hollow molded article having significantly improved quality.

More specifically, the present invention relates to a hollow polyester molded product which is excellent in heat resistance, transparency, drop strength and the like, and is also excellent in blocking ultraviolet rays, and which is suitable for food and beverage containers.

[0003]

2. Description of the Related Art Polyester is a carbonated beverage, tea beverage, juice, and mineral water that takes advantage of its excellent mechanical strength, transparency, heat resistance, gas barrier properties, and lighter weight than glass. It is used for beverage containers and food containers.

However, the hollow molded articles made of polyester that have been used so far have insufficient heat resistance, so that they may not be filled at a high temperature or may not be sufficiently washed and sterilized for recycling. . In addition, the ultraviolet ray blocking property is not sufficient, and the beverage / food in the container may deteriorate. Therefore, in recent years, there has been a demand for a material having properties further superior to those of the polyesters used so far in terms of heat resistance and ultraviolet ray blocking property.

In order to improve the heat resistance of polyethylene terephthalate (hereinafter sometimes referred to as PET), for example, Japanese Patent Laid-Open No. 11-152396 discloses:
PET with polyethylene-2,6-naphthalate (hereinafter,
A study example of a hollow molded article made of a resin mixed with PEN) is also described. However, since PET and PEN have poor compatibility with each other, they are milky white and inferior in transparency simply by blending them normally. Therefore, in order to obtain a transparent blend, transesterification reaction by melt mixing needs to occur, but in order to obtain sufficient transparency, a long reaction time is required at a temperature equal to or higher than the melting point of the resin. Here, increasing the reaction time or increasing the temperature of the molten resin to accelerate the reaction causes problems such as deterioration of the resin and thermal decomposition products.
From the viewpoint of flavor adsorption and mechanical strength, it may be unfavorable as a hollow molded article for beverage / food.

Further, Japanese Patent Publication No. 1-49384 discloses that PET is used to improve heat resistance and gas barrier properties.
Describes a study example on a hollow molded article molded from a composition comprising polyethylene isophthalate. However, the crystallization speed of polyethylene isophthalate may be slow, resulting in poor moldability or insufficient pressure resistance when filled with a carbonated beverage.

On the other hand, a composition in which polyester and polyimide are mixed has been described in the past, for example, polyethylene terephthalate is used as the polyester,
It has been shown that, when polyetherimide (PEI) is used as the polyimide and compositions with various mixing ratios are prepared, the glass transition temperature rises with an increase in the weight fraction of PEI (for example, “Journal of Applied Polymer Science (JOURNAL of APPLIED POLYMER
SCIENCE) "1993, 48, 935-937," Macromolecules "1995, 28, 28
45 to 2851, "Polymer," 1997, Volume 38,
4043-4048 "). There are also studies on biaxially oriented polyester films composed of a mixture of PET and PEI (for example, Japanese Patent Laid-Open Nos. 2000-141475 and 2000-
309650, JP 2000-309651 A, etc.). According to the study example, a base film suitable for a magnetic recording medium, a thermal transfer ribbon, and a capacitor, which has improved thermal dimensional stability due to an increase in glass transition temperature, has been proposed.

Further, Japanese Patent Laid-Open No. 10-204268 and Japanese Patent Laid-Open No.
Japanese Unexamined Patent Publication No. 10-195292 describes a resin composition composed of polyethylene terephthalate and a specific polyimide, and a hollow molded product composed of the resin composition. However, if polyimide is simply mixed with polyester, a large amount of coarse foreign matter is generated in the hollow molded body, which may lower the drop strength, or may cause thermal deformation or transparency of the hollow molded body.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high quality polyester hollow molded article which is excellent in heat resistance, drop strength, transparency and ultraviolet ray blocking property by improving the drawbacks of the prior art.

[0010]

In order to solve the above problems, the hollow polyester polyester of the present invention mainly has the following constitution. That is, the number of coarse foreign matters containing polyester (A) and polyimide (B) and having a size of 10 μm or more is 1
00 pieces / g or less, and the total amount of metal elements is 3 to 450 p
It is a polyester hollow molding which is pm.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester (A) constituting the polyester hollow molded article of the present invention comprises, for example, an acid component such as an aromatic dicarboxylic acid, an alicyclic dicarboxylic acid or an aliphatic dicarboxylic acid, and a diol component. It

As the aromatic dicarboxylic acid component, for example, terephthalic acid, isophthalic acid, phthalic acid, 1,4-
Naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, etc. Of these, terephthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid can be preferably used. As the alicyclic dicarboxylic acid component, for example, cyclohexanedicarboxylic acid or the like can be used. As the aliphatic dicarboxylic acid component, for example, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, etc. can be used. These acid components may be used alone or in combination of two or more.

As the diol component, for example, ethylene glycol, 1,2-propanediol, 1,3-
Propanediol, neopentyl glycol, 1,3-
Butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, Triethylene glycol, polyalkylene glycol, 2,2'-bis (4'-β-hydroxyethoxyphenyl) propane or the like can be used,
Of these, ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol,
Diethylene glycol or the like can be used, and particularly preferably ethylene glycol or the like can be used.
These diol components may be used alone or in combination of two or more.

The polyester may be copolymerized with a monofunctional compound such as lauryl alcohol and phenyl isocyanate, or trimellitic acid, pyromellitic acid, glycerol, pentaerythritol, 2,4-
A trifunctional compound such as dioxybenzoic acid may be copolymerized within a range in which the polymer is substantially linear without excessive branching or crosslinking. In addition to the acid component and the diol component, aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid, m-hydroxybenzoic acid and 2,6-hydroxynaphthoic acid, and p-aminophenol and p-aminobenzoic acid are also included in the present invention. If it is a small amount that does not impair the effect of, it can be further copolymerized.

The polyester (A) of the present invention is not particularly limited, but from the viewpoint of mechanical strength, productivity and handleability, ethylene terephthalate and / or ethylene-2,6-naphthalenedicarboxylate units are the main constituent components. Is preferably at least one selected from the group consisting of polyesters and modified products thereof. Among these, at least 8 as a constituent
Polyesters containing 0 mol% or more ethylene terephthalate units are particularly desirable. This is because the polyester containing ethylene terephthalate unit as the main constituent is
This is because the molding process is easier than the polyester having ethylene-2,6-naphthalene dicarboxylate unit as a main constituent.

The polyester (A) of the present invention can be produced by a conventionally known production method. For example, in the case of polyethylene terephthalate, a direct ester method in which terephthalic acid and ethylene glycol are directly reacted to remove water and esterify, and then polycondensation is performed under reduced pressure, dimethyl terephthalate and ethylene glycol are reacted to form methyl alcohol An example is a transesterification method in which polycondensation is performed under reduced pressure after removal and transesterification.

As the transesterification catalyst in the transesterification method, a carboxylic acid metal salt compound of a metal element such as manganese, zinc, cobalt and magnesium and a carboxylic acid such as acetic acid is used, and as a polycondensation reaction catalyst,
A germanium compound, an antimony compound, a titanium compound, etc. are used. Further, in order to reduce the activity of the transesterification reaction, a phosphorus compound such as phosphoric acid or trimethyl phosphate can be added after the completion of the ester reaction. In the case of the direct esterification method, a germanium compound, an antimony compound, a titanium compound or the like is used as the polycondensation catalyst. The polycondensation catalyst is not particularly limited, but a germanium compound is preferably exemplified because of the transparency of the polyester composition of the present invention.

The polyimide (B) of the present invention is not particularly limited, but is preferably a polymer containing a cyclic imide group as a repeating unit, and preferably a polymer having melt moldability. For example, U.S. Pat. No. 4,141
No. 927, Japanese Patent No. 2622678, Japanese Patent No. 2606912, Japanese Patent No. 2606914,
Polyether imides such as Japanese Patent No. 2596565, Japanese Patent No. 2596566 and Japanese Patent No. 2598478, Japanese Patent No. 2598536, Japanese Patent No. 2599
No. 171, Japanese Patent Laid-Open No. 9-48852, and Japanese Patent No. 2
Japanese Patent No. 565556, Japanese Patent No. 2564636, Japanese Patent No. 2564637, Japanese Patent No. 2563548, Japanese Patent No. 2563547, Japanese Patent No. 2555834.
No. 1, Japanese Patent No. 2558339, Japanese Patent No. 283
Examples thereof include the polymers described in Japanese Patent No. 4580. Within the range in which the effects of the present invention are not impaired, structural units other than cyclic imide in the main chain of the polyimide (B), such as aromatic, aliphatic, alicyclic, alicyclic ester units, oxycarbonyl units, etc. Needless to say, may be contained.

The polyimide (B) of the present invention is represented by the following general formula.

[0020]

[Chemical 1] Ar in the above formula is an aromatic group having 6 to 42 carbon atoms, R is a divalent aromatic group having 6 to 30 carbon atoms, and a fat having 2 to 30 carbon atoms. Group,
It is a divalent organic group selected from the group consisting of alicyclic groups having 4 to 30 carbon atoms. As Ar, for example,

[0021]

[Chemical 2] Can be mentioned. As R, for example,

[0022]

[Chemical 3] Can be mentioned.

These are within the range which does not inhibit the present invention,
One kind or two or more kinds may be present together in the polymer chain.

The polyimide (B) of the present invention is not particularly limited, but as a preferable example from the viewpoint of melt moldability with the polyester (A) and handleability, for example, as shown by the following general formula, polyimide composition is shown. An example is polyether imide, which is a polymer that is a structural unit containing an ether bond as a component.

[0025]

[Chemical 4] However, in the above formula, R ₁ is a divalent organic group selected from the group consisting of divalent aromatic or aliphatic groups having 2 to 30 carbon atoms and alicyclic groups.

Examples of R ₁ and R ₂ include aromatic groups represented by the following formula group:

[0027]

[Chemical 5] Can be mentioned.

In the present invention, when a polyetherimide having a glass transition temperature of 350 ° C. or lower, more preferably 250 ° C. or lower is used, the effects of the present invention are easily obtained, and compatibility with the polyester (A), melt moldability, etc. From the viewpoint, 2,2-bis [4- (2, having a structural unit represented by the following formula:
A condensate of 3-dicarboxyphenoxy) phenyl] propane dianhydride and m-phenylenediamine or p-phenylenediamine is preferable.

[0029]

[Chemical 6] This polyetherimide is "Ultem" (registered trademark)
It is available from GE Plastics, Inc.

The above polyimide can be manufactured by a known method. For example, a group consisting of a tetracarboxylic acid and / or an acid anhydride thereof as a raw material capable of inducing Ar and an aliphatic primary diamine and / or an aromatic primary diamine as a raw material capable of inducing R. It can be obtained by dehydration-condensation of one or more compounds selected from the following. Specifically, a method of obtaining a polyamic acid and then subjecting it to ring closure by heating can be exemplified. Alternatively, a method in which an acid anhydride and a chemical ring-closing agent such as pyridine or carbodiimide are used for chemical ring closure, or the tetracarboxylic acid anhydride and the diisocyanate capable of inducing R are heated to decarboxylate and polymerize A method etc. can be illustrated.

The tetracarboxylic acid used in the above method is, for example, pyromellitic acid, 1, 2, 3, 4
-Benzene tetracarboxylic acid, 3, 3 ', 4, 4'-
Biphenyl tetracarboxylic acid, 2, 2 ', 3, 3'-
Biphenyl tetracarboxylic acid, 3, 3 ', 4, 4'-
Benzophenone tetracarboxylic acid, 2, 2 ', 3,
3'-benzophenone tetracarboxylic acid, bis (2,3
-Dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane, 1,1'-bis (2,
3-dicarboxyphenyl) ethane, 2,2'-bis (3,4-dicarboxyphenyl) propane, 2,
2'-bis (2,3-dicarboxyphenyl) propane, bis (3,4-dicarboxyphenyl) ether, bis (2,3-dicarboxyphenyl) ether, bis (3,4-dicarboxyphenyl) sulfone Bis (2,3-dicarboxyphenyl) sulfone, 2,3,6,7-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid Acids such as 2,2'-bis [(2,3-dicarboxyphenoxy) phenyl] propane and / or acid anhydrides thereof are used.

As the diamine, for example, benzidine, diaminodiphenylmethane, diaminodiphenylethane, diaminodiphenylpropane, diaminodiphenylbutane, diaminodiphenylether, diaminodiphenylsulfone, diaminodiphenylbenzophenone,
o, m, p-phenylenediamine, tolylenediamine, xylenediamine and the like, and aromatic primary diamines having a hydrocarbon group of the exemplified aromatic primary diamine as a structural unit, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 2,2-dimethyl-1,3-propanediamine, 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,9
-Nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12
-Dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,3-cyclohexanediamine,
1,4-cyclohexanediamine, 1,4-cyclohexanedimethylamine, 2-methyl-1,3-cyclohexanediamine, isophoronediamine and the like, and hydrocarbon groups of these exemplified aliphatic and alicyclic primary diamines as structural units. Examples thereof include aliphatic and alicyclic primary diamines.

In the polyester hollow molded article of the present invention, the number of coarse foreign matters having a size of 10 μm or more present in the composition must be 100 pieces / g or less. When the number of the coarse foreign matters contained in 1 g of the composition exceeds 100, the heat resistance and the transparency are deteriorated, and the drop strength of the hollow molded article for food is significantly reduced. A more preferable range of coarse foreign matter is 60 /
g or less, most preferably 30 / g or less.

Further, the polyester hollow molded article of the present invention must have a total amount of metal elements of 3 to 450 ppm. If the total amount of metal elements exceeds 450 ppm, a large amount of coarse foreign substances due to the reaction product of the polyester (A) or the polyimide (B) and the thermally deteriorated product of the polyester are generated in the composition during melt extrusion. As a result, the drop strength of the hollow molded article is reduced, and further, the transparency and heat resistance are significantly reduced, which makes it difficult to use. Further, if the metal content is less than 3 ppm, the amount of catalyst during polyester polymerization becomes too small, and a long polymerization time is required. The more preferable range of the metal content is 5 to 1
00 ppm, and the most preferred range is 10 to 50 ppm.

The hollow polyester molded product of the present invention contains the polyester (A) and the polyimide (B), and is preferably a mixture of both. The term “compatibility” as used herein means that the obtained chips have a single glass transition temperature (Tg). It is generally known that the Tg when both are compatible with each other exists between the Tg of the polyester (A) and the Tg of the polyimide pellets (B). The glass transition temperature in the present invention is determined from the heat flux gap at the time of temperature rise in the differential scanning calorimetry according to JIS K
7121. When it is difficult to make a determination only by the method of differential scanning calorimetry, a morphological method such as dynamic viscoelasticity measurement or microscopic observation may be used together. When the glass transition temperature is determined by differential scanning calorimetry, it is also effective to use a temperature modulation method or a high sensitivity method.

The polyester resin composition used in the hollow molded article of the present invention has the above-mentioned single glass transition temperature (Tg).
Is preferably 90 to 180 ° C. Tg is more preferably 95 to 170 ° C., further preferably 100 to
It is in the range of 160 ° C. In the case of a polyester composition containing a polyester (A) containing 80 mol% or more of ethylene terephthalate units as constituent components of the polyester (A) and a polyimide (B),
A preferred Tg range is 95 to 150 ° C, and a more preferred Tg range is 100 to 140 ° C. If the single Tg is within such a preferable range, the polyester composition of the present invention is molded into a food product such as a hollow molded product.
When used as a beverage container, it has sufficient heat resistance and is excellent in molding processing such as melt moldability.

When the polyester (A) and the polyimide (B) are made compatible with each other, the timing of adding the polyimide (B) to the polyester (A) is not particularly limited, but before the polymerization of the polyester, for example, before the esterification reaction. It may be added, or may be added after the polymerization and before the melt extrusion.

Among them, polyester (A) and polyimide (B) are supplied to a twin-screw extruder so that the polyimide (B) has a high concentration and melt-extruded to obtain master pellets having a high concentration of polyimide (B). Create. Then, the master pellet and the polyester (A) are supplied to an extruder and melt-molded to obtain a polyester hollow molded article having a low polyimide concentration (40 parts by weight or less) (high-concentration master dilution method). Are particularly preferable for obtaining the polyester hollow body of the present invention.

The total amount of polyester cyclic trimer oligomer of the polyester resin used in the molded article of the present invention is preferably 0.4% by weight or less. The content is more preferably 0.3% by weight or less, and further preferably 0.2% by weight or less. When the amount of the cyclic trimer oligomer is 0.4% by weight or less, the oligomer does not impair the flavor of the contents and does not deteriorate the heat resistance and the transparency, and is preferably used.

The polyester hollow molded article of the present invention preferably has a carboxyl terminal group amount of 50 × 10 ⁻⁶ equivalent / g or less. The more preferable carboxyl terminal group amount is 40 × 10 ⁻⁶ equivalent / g or less, and further preferably 30 × 10 ⁻⁶ equivalent / g or less. When the carboxyl terminal group amount of the polyester composition is within such a preferable range, deterioration of the polyester composition is not promoted, polyester oligomers and the like are less likely to occur, and heat resistance and transparency are not deteriorated. For example, when the polyester composition is processed into a hollow molded article and used, the heat resistance and strength are sufficient, and the flavor of the contents of the hollow molded article is not impaired.

The content of the polyimide (B) in the hollow polyester molded product used in the molded product of the present invention is 1 to 40.
It is preferably in the range of% by weight. More preferably, it is in the range of 5 to 30% by weight, and even more preferably 7
-25% by weight. Although the melt viscosities of the polyester (A) and the polyimide (B) are largely different, if the content of the polyimide (B) is within the above-mentioned preferable range, it is easy to obtain sufficient kneading with an extruder and to be compatible with each other. On the other hand, the molding process is also easy.

The intrinsic viscosity of the polyester (A) of the present invention is in the range of 0.60 to 1.5 (dl / g) from the viewpoint of stability of molding process and miscibility with the polyimide (B). Is preferable, and more preferably 0.7 to 1.2.
(Dl / g). Further, the intrinsic viscosity of the polyester composition of the present invention, from the viewpoint of stability of the molding process,
The range is preferably 0.55 to 1.3 (dl / g), and more preferably 0.65 to 1.15 (dl / g).
g).

The polyester hollow molded article of the present invention is a heat stabilizer, an antioxidant, a terminal cross-linking agent, an ultraviolet absorber, an antistatic agent, a flame retardant, a pigment, a dye, a fatty acid ester, as long as the present invention is not impaired. An organic lubricant such as wax may be added.

The polyester hollow molded article of the present invention is 80
It is preferable that the shrinkage rate of the body portion at 0 ° C. is in the range of 0.01 to 5%. A more preferable body part contraction rate is 0.0
It is in the range of 1 to 3%, more preferably 0.01
Is in the range of 2%. When the body part shrinkage ratio is within the above-mentioned preferred range, for example, when the hollow molded body is used as a tea beverage container, hot filling (hot filling) is performed, but the heat resistance is sufficient. Further, the heat resistance is sufficient even when the hollow molded body is heat-sterilized.

The polyester hollow molded article of the present invention is provided with another polymer layer, for example, a layer made of another polyester, polyolefin, polyamide, polyvinylidene chloride or acrylic polymer, directly or through a layer such as an adhesive. You may make it laminated | stacked.

The polyester hollow molded article of the present invention preferably has an ultraviolet transmittance of 50% or less at a wavelength of 370 nm. More preferably 40% or less, still more preferably 30
% Or less. When the ultraviolet light transmittance is within such a preferable range, the content of the hollow molded body does not deteriorate.

The low molecular weight compound contained in the polyester hollow molded article of the present invention is preferably 50 ppm or less. When the amount of the low molecular weight compound is 50 ppm or less, gelation of the polyester is reduced and coarse foreign matters are reduced, so that a hollow molded article having excellent drop strength and transparency can be obtained. The more preferable range of the amount of low molecular weight compound is 3
0 ppm or less, and the most preferable range is 20 ppm or less.

The low molecular weight compound mentioned here means a molecular weight of 3
It is a compound of 00 or less. These low molecular weight compounds are often residues of the solvent used as a polymerization solvent for polyimide, and it is difficult to completely remove these low molecular weight compounds by a usual method. Examples of low molecular weight compounds include dichlorobenzene, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoric triamide, dimethylmethoxyacetamide, N-methyl. One of caprolactam, dimethyl sulfone, tetramethyl sulfone, N-acetyl-2-pyrrolidone, or two or more thereof is exemplified.

The polyester hollow molded article of the present invention is provided with another polymer layer, for example, a layer made of another polyester, polyolefin, polyamide, polyvinylidene chloride or acrylic polymer, directly or through a layer such as an adhesive. You may make it laminated | stacked.

Hereinafter, an example of the method for producing the polyester hollow molded article of the present invention will be described, but the method is not limited thereto. Here, an example is shown in which polyethylene terephthalate is used as the polyester (A) and polyetherimide "Ultem" (registered trademark) is used as the polyimide (B), but the details of the production conditions differ depending on the polyester or polyimide used.

First, bishydroxyethyl terephthalic acid was dissolved at 250 ° C. according to a conventional method. After that, a mixed slurry of terephthalic acid and ethylene glycol was fed for 1 to 3 hours so that the temperature in the reaction system did not fall below 240 ° C., an ester exchange reaction was performed, and then germanium dioxide as a polymerization catalyst and a heat stabilizer as a heat stabilizer. Polyethylene terephthalate (hereinafter PE
T) (polyester (A)) is obtained. Here, the intrinsic viscosity of PET is about 0.6. At this time, a predetermined amount of polyetherimide may be added.

The obtained polyester is preferably solid-state polymerized in a pellet form under reduced pressure. Furthermore, it is also effective to apply steam or hot water treatment as needed.
In the case of solid phase polymerization, pre-crystallization is performed at a temperature of 180 ° C. or lower in advance, and then solid phase polymerization is performed at 190 to 250 ° C. under a reduced pressure of about 1 mmHg for 10 to 50 hours. further,
When the hot water treatment is performed, the hot water treatment at 90 to 100 ° C. is performed for 8 hours.

Next, the polyethylene terephthalate pellets (A) and the polyetherimide pellets (B).
Are mixed at a constant ratio and supplied to a kneading extruder heated to a melting point of the polyester (A) or higher, for example, a temperature of 270 to 320 ° C., and melt-extruded. The kneading extruder is not particularly limited, but a deaeration type, for example, a vent type twin-screw kneading extruder is preferable. The residence time at this time is 0.5 to 15
Minutes are preferable, and more preferably 1 to 10 minutes. By the above kneading, polyethylene terephthalate and polyether imide are compatible with each other, and pellets of a polyester composition having a single glass transition point can be obtained.

The polyester resin molded product of the present invention can be manufactured by molding using a known injection molding machine.
For example, a bottom preform (parison) is placed in a blow bottle mold, air is blown from the blow pin at the opening to inflate it to form a bottle (direct blow method), or the parison is stretched by a stretch blow molding machine. It can be molded by a two-step method of blow molding, or a one-step method of stretch blow molding (stretch blow method) in which molding of a parison and stretch blow molding are performed by the same machine.

For example, the stretch blow method will be described as an example. After vacuum-drying the polyester composition of the present invention at 180 ° C. for 3 hours or more, the polyester composition is melted and plasticized by being supplied to an extruder heated to 260 to 320 ° C. under a nitrogen stream or under vacuum so that the intrinsic viscosity does not decrease. The polyester composition, screw rotation from the die head, plunger extrusion,
A parison is molded using a molding machine such as an accumulator. The molding temperature during parison molding is preferably 23
It is in the range of 0 to 300 ° C, more preferably 240 to 280 ° C. The parison molding cycle is preferably 40 seconds or less, and particularly preferably 30 seconds or less. The hollow molded article comprising the polyester composition of the present invention is obtained by molding a parison from the polyester composition and then subjecting the parison to an area stretching ratio (the product of the longitudinal stretching ratio and the transverse stretching ratio) of 6 to 1
It is obtained by stretch blow molding at 5 times. Prior to the stretch blow molding, the mouth and neck of the parison may be heated and crystallized, or the mouth and neck of the hollow molded body obtained after the stretch blow molding may be heated and crystallized. Normal,
Before stretch blow molding, it is preferable to heat and crystallize the mouth and neck of the hollow molded body.

When forming a stretched hollow molded body from a parison, it is also possible to heat the parison directly in a mold, pressurize a blow fluid, and perform stretch blow at the above area stretching ratio to form a hollow molded body. . Alternatively, the parison may be stretch-blown to form a hollow container, which may be cooled, and then stretch-blow molded under heating while filling the mold to form a hollow molded article having a desired shape. . Examples of the blow fluid include air, nitrogen, steam, water, etc.
Preference is given to using air.

In the present invention, the hollow molded article obtained as described above may be heat set. The heat setting is usually 100 to 200 for the obtained hollow molded article.
C., preferably 110 to 170.degree. C., at a mold temperature of usually 1 second or longer, preferably 3 seconds or longer. By heat-setting the hollow molded body in this manner, it is possible to improve the density and obtain a hollow molded body having improved strength.

In the present invention, the blow molded article which has been subjected to direct blow molding or stretch blow molding and, if necessary, heat set, is cooled so as to suppress deformation, shrinkage, etc. when taken out from the mold. It is preferable to take it out. Here, as the cooling method, for example, it is preferable to use an internal cooling method of cooling the hollow molded body from the inside to the outside by blowing a cooled gas or the like into the hollow molded body. By thus cooling the hollow molded body from the inside, the hollow molded body can be taken out of the mold while suppressing deformation, shrinkage and the like. [Physical property measuring method and effect evaluating method] The characteristic value measuring method and effect evaluating method are as follows. (1) A sample piece (1 g) was cut from the body of a coarse foreign substance hollow molded body, dissolved in orthochlorobenzene (20 cc), and 1 μm
m Filter with a membrane filter. The membrane filter was observed with an optical microscope to count coarse foreign matters of 10 μm or more. (2) Content of metallic element By fluorescent X-ray, germanium, antimony, titanium,
The intensity of each element amount of magnesium was quantified by comparing with the calibration curve obtained from each standard substance. (3) Body Shrinkage of Hollow Molded Body The hollow molded body was filled with hot water at 80 ° C., immersed in a hot bath at 80 ° C. for 30 minutes and then taken out, and the volume change before and after the treatment was measured. (4) Drop strength After filling a molded hollow molded body with water and sealing it with an aluminum or plastic cap, after dropping from a height of 2 m five times or more, the falling portion of the bottom of the hollow molded body is observed. It was judged according to the standard.

Good: No leakage of contents occurred.

Bad: The contents leaked. (5) Sample section (thickness of about 0.5 m from the body of haze hollow molding)
m) was cut out and measured according to JIS K 6714 using a haze meter manufactured by Suga Test Instruments. The internal haze was measured while immersed in tetralin. (6) Ultraviolet transmittance Sample piece (thickness of about 0.5 m from the body of the hollow molding)
m) is cut out and spectrophotometer (U-43 manufactured by Hitachi, Ltd.)
10) was used for the measurement. The ratio (%) of the light having a wavelength of 370 nm is shown. (7) Glass transition temperature (Tg) The specific heat was measured by the pseudo-isothermal method using the following equipment and conditions.
Glass transition temperature (Tg) according to JIS K 7121
It was determined.

Device: Temperature modulation DSC manufactured by TA Instrument Measurement conditions: Heating temperature: 270-570K (RCS cooling method) Temperature calibration: High purity indium and tin melting point Temperature modulation amplitude: ± 1K Temperature modulation cycle: 60 second temperature rise Step: 5K Sample weight: 5 mg Sample container: Aluminum open container (22 mg) Reference container: Aluminum open container (18 mg) The glass transition temperature (Tg) is the glass transition temperature of the following equation = (extrapolated glass transition) Calculated by (starting temperature + extrapolated glass transition end temperature) / 2. (8) Carboxyl end group content The polyester composition is dissolved in orthocresol / chloroform (weight ratio 7/3) at 90 to 100 ° C., and the potential difference is measured with an alkali. The unit used was equivalent weight / g. (9) Intrinsic viscosity The value calculated from the following formula from the solution viscosity measured at 25 ° C in orthochlorophenol is used. That is, ηsp / C = [η] + K [η] 2 · C, where ηsp = (solution viscosity / solvent viscosity) -1, C is the weight of dissolved polymer per 100 ml of solvent (g / 100 ml,
Normally 1.2), K is Huggins constant (0.343)
Is. The solution viscosity and the solvent viscosity were measured using an Ostwald viscometer.

[0062]

EXAMPLES The embodiments of the present invention will be described based on the following examples. (Example 1) Bishydroxyethyl terephthalic acid 132
Melt parts by weight at 250 ° C. Then terephthalic acid 86
1.5 parts by weight of a mixed slurry of 38 parts by weight of ethylene glycol so that the temperature in the reaction system does not fall below 240 ° C
After feeding over time and carrying out the transesterification reaction,
Germanium dioxide as a polymerization catalyst and phosphoric acid as a heat stabilizer were added to carry out a polycondensation reaction to obtain PET (polyester (A)). The obtained PET has an intrinsic viscosity of 0.6.
It was 2. Then, after preliminarily crystallizing at a temperature of 130 ° C., solid phase polymerization was performed at 180 ° C. under a reduced pressure of about 1 mmHg. By changing the polymerization time, PETs with intrinsic viscosities of 0.62 and 0.77 were obtained.

The resulting PET (intrinsic viscosity 0.77) pellets (50 parts by weight) and the polyetherimide (a) (weight average molecular weight = 3) were dried by hot air at 150 ° C. for 5 hours.
2,000, carboxyl end group amount = 12.5 equivalents / 1
0 ⁶ g, amino end group amount = 5.3 equivalents / 10 ⁶ g (registered trademark “Ultem” 101, manufactured by GE Plastics Co., Ltd.)
0)) (polyimide (B)) (50 parts by weight) was dry-blended and melt-kneaded using a co-rotating twin-screw kneading extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.). The kneading was performed under the conditions of an extrusion temperature of 310 ° C., a residence time of 3.5 minutes, and a vent vacuum degree of 0.5 mmHg. The mixture was discharged in a strand form from the die and cooled with water, and then pelletized to obtain pellets (I) of PET / polyetherimide (a) (50/50).

Then, the pellet (I) (40 parts by weight) vacuum-dried at 180 ° C. for 3 hours and polyethylene terephthalate (intrinsic viscosity 0.62) (60 parts by weight) were dry blended, and the co-rotating biaxial kneading was performed. Melt kneading was performed again using an extruder (TEM-35B manufactured by Toshiba Machine Co., Ltd.). The kneading was performed under the conditions of an extrusion temperature of 300 ° C., a residence time of 3.5 minutes, and a vent vacuum degree of 0.5 mmHg.
A pellet (II) of polyetherimide (a) (80/20) was obtained. The resulting composition had excellent compatibility and transparent pellets were obtained.

Next, in order to obtain a hollow molded article using the polyester composition, the pellets (II) were vacuum dried at 180 ° C. for 3 hours and then fed to an extruder heated to a temperature of 280 ° C. A preform (parison) was molded by a known injection molding machine. The molding temperature was 280 ° C., and the molding cycle was 30 seconds. This parison has a conductor center of 115 ° C.
And was blow-molded in the longitudinal direction 2.5 times and in the transverse direction 5 times to obtain a biaxially stretched hollow molded body.

As shown in Tables 1 and 2, the number of coarse foreign matters in the obtained polyester hollow molded article was 43 pieces / 1 g, and the metal element content was 24 ppm (Ge). Its characteristics are
The hollow molded article had excellent heat resistance and transparency, and also had excellent drop strength because it contained few coarse foreign matters.

[0067]

[Table 1]

[0068]

[Table 2] Comparative Example 1 Polyethylene terephthalate (PET) having an intrinsic viscosity of 1.0 was obtained in the same manner as in Example 1 except that the catalyst formulation was changed.

Pellets of PET obtained (80% by weight)
And hot-air dried polyetherimide (b) at 150 ° C. for 5 hours (weight average molecular weight = 60,000 (GE Plastics Co., Ltd., registered trademark “Ultem” 1000))
(20% by weight) is dry-blended and melt-kneaded using a twin-screw kneading extruder under conditions of an extrusion temperature of 285 ° C. and a residence time of 20 minutes to obtain PET / polyetherimide (b).
(80/20) pellets were obtained. When produced by this method, the resulting composition had poor dispersibility and was a cloudy pellet.

Next, the pellets were subjected to stretch blow molding in the same manner as in Example 1 to obtain a hollow molded body.

As shown in Tables 1 and 2, the obtained polyester hollow molded article had 327 coarse foreign substances / g and a metal element content of 361 ppm (Ge: 241 ppm, Mg:
It was 120 ppm). The hollow molded article had poor heat resistance and transparency, and also had poor drop strength due to the large amount of coarse foreign matter. (Examples 2 and 3) In the same manner as in Example 1, PET /
Pellets (I) of polyetherimide (a) (50/50% by weight) were obtained.

Then, pellets (II) were prepared in the same manner as in Example 1 except that the mixing ratio of PET and pellets (I) was changed to obtain hollow molded bodies.

As shown in Tables 1 and 2, the properties of the obtained polyester hollow molded article are excellent in heat resistance and transparency, and also have excellent drop strength because there are few coarse foreign matters. It was (Example 4) N-methyl-2-pyrrolidone (NMP) 3 was added to 200 g of isophorone diisocyanate under a nitrogen atmosphere.
Add to 000 ml and stir. Next, 196 g of pyromellitic dianhydride is added to this solution at room temperature, and then the temperature is gradually raised. After that, when heated at 180 ° C. for 6 hours, the generation of carbon dioxide was completed, so the heating was stopped. After the polymer solution was developed in water and washed, the polymer obtained here was dried to obtain a polyimide (c).

A hollow molded article was obtained in the same manner as in Example 1 except that the polyimide (c) was used as the polyimide (B).

As shown in Tables 1 and 2, the properties of the obtained polyester hollow molded article are excellent in heat resistance and transparency, and also have excellent drop strength because there are few coarse foreign matters. It was (Example 5) To a mixture of 100 parts by weight of dimethyl 2,6-naphthalate dicarboxylate and 52 parts by weight of ethylene glycol, 0.04 parts by weight of magnesium acetate was added, heated and heated to distill off methanol. A transesterification reaction was performed. Then, trimethyl phosphate was added as a heat stabilizer to the transesterification product to obtain polyethylene-2,6-naphthalate (PEN). Here, the intrinsic viscosity of PEN was 0.65.

A hollow molded article was obtained in the same manner as in Example 1 except that the PEN pellets were used as the polyester (A).

As shown in Tables 1 and 2, the properties of the obtained polyester hollow molded article are excellent in heat resistance and transparency, and also have excellent drop strength because there are few coarse foreign matters. It was (Example 6) In the same manner as in Example 1 except that the catalyst formulation at the time of polymerization of polyester (A) (PET) was changed,
A hollow molded body was obtained.

As shown in Tables 1 and 2, the number of coarse foreign matters in the obtained polyester hollow molded article was 8 pieces / 1 g, and the metal element content was 4 ppm (Ge). The properties were a hollow molded product having excellent heat resistance and transparency, and also having significantly excellent drop strength because there were few coarse foreign matters. (Example 7) Polyetherimide (a) (GE Plastics Co., Ltd., registered trademark "Ultem" 1010, ortho-dichlorobenzene (ODB): containing 320 ppm)
Is a biaxial shearing crusher (MTC-2038, manufactured by Oike)
Was crushed using. The crushed diameter was 200 mesh. The obtained polyetherimide powder was put into a rotary vacuum dryer. Vacuum degree is 2mmHg and 300 at 180 ℃
The low molecular weight compound was removed while stirring for 1 minute. 99% or more of the low molecular weight compounds contained in the obtained powdery polyetherimide (a) are dichlorobenzene (DC).
B), and its content was 55 ppm.

A hollow molded body was obtained in the same manner as in Example 1 using the powdered polyetherimide.

As shown in Tables 1 and 2, the number of coarse foreign matters in the obtained polyester hollow molded article was 12 pieces / 1 g, and the metal element content was 24 ppm (Ge). Its characteristics are
The hollow molded article had excellent heat resistance and transparency, and also had excellent drop strength because it contained few coarse foreign matters. Comparative Example 2 Polycondensation reaction was carried out in the same manner as in Example 1 to give polyethylene terephthalate (P
ET).

Pellets of PET obtained (80% by weight)
And a polyetherimide (b) (weight average molecular weight = 60,000 (GE Plastics Co., Ltd. registered trademark: Ultem 1000)) dried with hot air at 150 ° C. for 5 hours (20
(Wt%) by dry blending, and melt-kneading is carried out using a twin-screw kneading extruder under conditions of an extrusion temperature of 285 ° C. and a residence time of 20 minutes to obtain PET / polyetherimide (b) (8).
0/20) pellets were obtained. When produced by this method, the resulting composition had poor dispersibility and was a cloudy pellet.

Next, the pellets were subjected to stretch blow molding in the same manner as in Example 1 to obtain a hollow molded body.

As shown in Tables 1 and 2, the number of coarse foreign matters in the obtained polyester hollow molded article was 142 pieces / 1 g, and the metal element content was 24 ppm (Ge). Its characteristics are
The hollow molded article was inferior in heat resistance and transparency, and was inferior in drop strength due to many coarse foreign matters. (Comparative Example 3) Polyethylene terephthalate (PET) was obtained by carrying out a polycondensation reaction in the same manner as in Example 1 except that the catalyst formulation was changed. Here, the intrinsic viscosity of PET is
By changing the polymerization time, 0.62 and 0.77 were obtained.

Next, in the same manner as in Example 1, a method of preparing pellets (I) of PET / polyetherimide (a) (50/50) once and further kneading with a twin-screw extruder (two-step kneading) Method) to obtain pellets (II) of PET / polyetherimide (a) (80/20).

Then, in the same manner as in Example 1, a hollow molded body was obtained.

As shown in Tables 1 and 2, the number of coarse foreign matters in the obtained polyester hollow molded article was 211 pieces / 1 g, the metal element content was 453 ppm (Ge: 185 ppm, Mg:
268 ppm). The characteristics were that the hollow molded article was inferior in drop strength because the metal element content was out of the range of the present invention, and coarse foreign matter increased in the melt-kneading process. (Comparative Example 4) Polyethylene terephthalate containing no polyimide was stretch blow-molded at 100 ° C, except that
A polyester hollow molding was obtained in the same manner as in Example 1.

The obtained polyester hollow molded article may not be practically usable in terms of heat resistance and ultraviolet ray blocking property.

[0088]

EFFECTS OF THE INVENTION Since the hollow molded article of the present invention comprises a composition of polyester and polyimide, it has higher heat resistance than the conventional hollow molded article composed only of polyester. By making the contents of foreign matters and metal atoms to be specific, it is possible to obtain a polyester hollow molded article with greatly improved drop strength, transparency, ultraviolet blocking property, and the like.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3E033 AA01 BA17 BA30 BB02 CA03                       CA07 CA18 CA20 FA03                 4F071 AA43 AA45 AA46 AA60 AF30Y                       AH05 BA01 BB05 BC04 BC10                 4J002 CF061 CF081 CM042 GG01

Claims (6)

[Claims] 1. A polyester (A) and a polyimide (B) are contained, and the number of coarse foreign matters of 10 μm or more is 100 / g.
The following, and the total amount of metal elements is 3 to 450 ppm, a hollow polyester body. 2. The hollow polyester molded product according to claim 1, wherein the ethylene terephthalate unit as a constituent of the polyester (A) is at least 80 mol% or more. 3. The hollow polyester molded product according to claim 1 or 2, wherein the polyetherimide unit as a constituent of the polyimide (B) is at least 80 mol% or more. 4. The hollow polyester body according to claim 1, wherein the polyimide (B) is 1 to 40% by weight. 5. The polyester hollow molded article according to claim 1, which has a single glass transition temperature. 6. The hollow polyester molded product according to claim 1, which has a haze of 5% or less.