JP2001226474A - Polyester, hollow molded article, sheet-like article and oriented film comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester which gives hollow molded articles, especially small hollow articles, sheet-like articles and oriented films having excellent transparency and heat-resistant dimensional stability, and containers and packaging materials for the articles, and to provide a molded article comprising the polyester film. SOLUTION: This polyester produced in the presence of a germanium compound as a catalyst, characterized by containing a compound containing at least one element selected from the group consisting of Al, Si, Fe, Sr, Zr, Sn, W and Pb in an element amount of 0.001 to 0.5 mol.% based on the acid component of the polyester and having a cyclic trimer increase amount of <=0.30 wt.%, when melted at a temperature of 290 deg.C for 60 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester suitably used as a material for a molded article such as a hollow molded container such as a beverage bottle, a film, a sheet, and the like, and a molded article comprising the same. TECHNICAL FIELD The present invention relates to a polyester which has good releasability from a heat-treating mold when molding a small hollow molded article and has excellent long-term continuous moldability. In particular, the molded article obtained from the polyester of the present invention has excellent crystallization control properties, and the resulting molded article hardly generates residual off-flavor and off-odor, and is small in size with excellent transparency and heat-resistant dimensional stability. A hollow molded article, a sheet-like material and a stretched film excellent in transparency, slipperiness and dimensional stability after molding are provided.

[0002]

2. Description of the Related Art Polyesters such as polyethylene terephthalate are excellent in both mechanical properties and chemical properties, and therefore have high industrial value, and include fibers, films, sheets, and the like.
Widely used as bottles.

[0003] As materials for containers such as seasonings, oils, beverages, cosmetics, and detergents, various resins are employed depending on the type of filling content and the purpose of use.

[0004] Among them, polyester is excellent in mechanical strength, heat resistance, transparency and gas barrier properties, and is therefore most suitable as a material for containers for filling beverages such as juices, soft drinks and carbonated drinks.

[0005] Such polyester is supplied to a molding machine such as an injection molding machine to form a preform for a hollow molded body, and the preform is inserted into a mold having a predetermined shape, stretch blow-molded, and then the body of the bottle is formed. Heat treatment (heat set)
Then, it is general that the plug portion of the bottle is heat-treated (the plug portion is crystallized) if necessary.

However, conventional polyesters contain oligomers such as cyclic trimers and the like, and these oligomers adhere to the inner surface of the mold, the exhaust port of the mold gas, and the exhaust pipe. Dirt was easy to occur.

Further, the polyester contains acetaldehyde which is a by-product. When the content of acetaldehyde in the polyester is large, the content of acetaldehyde in the material of a container or other packaging formed therefrom also increases, which affects the flavor and odor of the beverage or the like filled in the container or the like. Therefore, various measures have conventionally been taken to reduce the acetaldehyde content in the polyester.

In recent years, containers made of polyester, mainly polyethylene terephthalate, have been used for mineral water and water.
It has been used as a container for low-flavor beverages such as long tea. In the case of such beverages, these beverages are generally heat-filled or sterilized by heating after filling, but the reduction of the acetaldehyde content of the beverage container alone may not improve the flavor and odor of these contents. I understand.

In addition, for the metal can for beverages, a metal plate coated with a polyester film having ethylene terephthalate as a main repeating unit is used for the purpose of simplifying the process, improving hygiene and preventing pollution. The method of making cans has been adopted. Also in this case, the contents are heat-sterilized at a high temperature after filling, and it has been found that the flavor and odor of the contents are not improved even if a film having a low acetaldehyde content is used.

As a method for solving such a problem,
JP-A-3-47830 discloses a polyethylene terephthalate.
There has been proposed a method of treating water in water, but it is necessary to perform water treatment for a long time in order to sufficiently exhibit the water treatment effect. In addition, when polyethylene terephthalate subjected to water treatment is molded as described above, an increase in oligomers such as cyclic trimers during melting cannot be ignored depending on the molding conditions, and the problem of mold contamination may occur. There are some cases that cannot be resolved.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art, and to further suppress the increase of the annular trimer during the melting of injection molding, thereby making the molding die dirty. It is an object of the present invention to provide a polyester which is difficult to obtain and which has good transparency of a bottle and crystallization of a plug portion.

[0012]

In order to achieve the above-mentioned object, the polyester of the present invention is a polyester produced using a germanium compound as a catalyst, and comprises Al, S
i, a compound containing at least one element selected from the group consisting of Fe, Sr, Zr, Sn, W, and Pb, in an amount of 0.001 to 0.
A polyester characterized by containing 5 mol% and increasing an amount of the cyclic trimer by 0.30% by weight or less when melted at a temperature of 290 ° C. for 60 minutes.

Polyester having the above-mentioned characteristics is less likely to cause stains in a molding die by further suppressing the increase of the cyclic trimer during melting during injection molding, and is excellent in crystallization controllability of the plug portion. And a hollow molded article, a sheet-like material, a stretched film, and a packaging material which are excellent in transparency, heat resistance, mechanical properties, residual off-flavor, and off-odor and have excellent fragrance retention. In this case, an alkali metal compound or an alkaline earth metal compound can be contained as an element in an amount of 0.001 to 1 mol% based on the acid component of the polyester.

In this case, the copolymerized diethylene glycol content may be 1.5 to 5.0 mol% of the glycol component constituting the polyester.

In this case, the acetaldehyde content can be 10 ppm or less. In this case, the polyester is a chip of the polyester and a fine 0.1 to 30 of a polyester having the same composition.
It can be a mixture with 0 ppm.

In this case, the polyester is substituted with ethylene terephthalate as its main repeating unit by 9
It can be a linear polyester containing 5 mol% or more. In this case, the polyester is substituted with its main repeating unit ethylene-2,6-naphthalate by 9
It can be a linear polyester containing 0 mol% or more.

In this case, the polyester formed into chips after polycondensation may be treated in a treatment tank with treated water satisfying the following conditions (a) and (b). (A) Temperature of 40 to 120 ° C (b) Treated water including wastewater from the treatment tank

In this case, the polyester formed into chips after the polycondensation may be treated in a treatment tank with treated water satisfying the following condition (c). (C) Treated water having a polyester fine powder content of 1000 ppm or less

The polyester obtained by the above-mentioned water treatment hardly causes mold stains during molding, has excellent crystallization controllability of the plug portion, and has excellent transparency and heat resistance.
A hollow molded article having excellent mechanical properties, residual off-flavors and off-flavors, and excellent in fragrance retention, and a sheet-shaped article excellent in transparency, slipperiness and dimensional stability after molding are provided. In this case, a hollow molded article made of the polyester, a sheet-like material, and a stretched film stretched in at least one direction can be used.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the polyester of the present invention will be specifically described. The polyester of the present invention is a crystalline polyester obtained mainly from an aromatic dicarboxylic acid component and a glycol component, preferably a polyester containing an aromatic dicarboxylic acid unit in an amount of 85% by mole or more of the acid component, more preferably Polyester containing an aromatic dicarboxylic acid unit in an amount of 90 mol% or more of the acid component.

The aromatic dicarboxylic acid component constituting the polyester of the present invention includes aromatic aromatic compounds such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid and diphenoxyethanedicarboxylic acid. And dicarboxylic acids and functional derivatives thereof.

Examples of the glycol component constituting the polyester of the present invention include aliphatic glycols such as ethylene glycol, trimethylene glycol and tetramethylene glycol, and alicyclic glycols such as cyclohexanedimethanol. Can be

The acid component used by copolymerization in the polyester includes terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, diphenyl-4,4 '.
-Aromatic dicarboxylic acids such as dicarboxylic acid, diphenoxyethane dicarboxylic acid, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, adipic acid, sebacic acid, succinic acid, glutaric acid, dimer acid And aliphatic derivatives thereof, and functional derivatives thereof, and alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, and cyclohexanedicarboxylic acid, and functional derivatives thereof.

The glycol components used in the polyester by copolymerization include aliphatic glycols such as ethylene glycol, trimethylene glycol, tetramethylene glycol, diethylene glycol and neopentyl glycol, bisphenol A and bisphenol A. And alicyclic glycols such as cyclohexanedimethanol, and polyalkylene glycols such as polyethylene glycol and polybutylene glycol.

Further, polyfunctional compounds such as trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid, glycerin, pentaerythritol, and trimethylolpropane are copolymerized within a range in which the polyester is substantially linear. Or a monofunctional compound such as benzoic acid or naphthoic acid.

One preferred example of the polyester of the present invention is
The main repeating unit is a polyester composed of ethylene terephthalate, more preferably a linear polyester containing at least 85 mol% of ethylene terephthalate units, particularly preferably a linear polyester containing at least 90 mol% of ethylene terephthalate units, that is, Polyethylene terephthalate (hereinafter abbreviated as PET).

Another preferred example of the polyester of the present invention is a polyester whose main repeating unit is composed of ethylene-2,6-naphthalate, more preferably 85% by mole or more of ethylene-2,6-naphthalate unit. A linear polyester containing ethylene-2,6-naphthalate units at 90 mol% is particularly preferable.
The linear polyester contained above, that is, polyethylene naphthalate homopolymer or polyethylene naphthalate copolymer containing ethylene terephthalate unit (hereinafter referred to as P
EN).

The intrinsic viscosity of the polyester of the present invention, particularly the polyester whose main repeating unit is composed of ethylene terephthalate, is preferably 0.50 to 1.30.
Deciliter / gram, more preferably 0.55-1.
20 deciliter / gram, more preferably 0.60
０．９0.90 deciliter / gram. If the intrinsic viscosity is less than 0.50 deciliter / gram, the obtained molded article or the like has poor mechanical properties. On the other hand, if it exceeds 1.30 deciliters / gram, the resin temperature rises during melting by a molding machine or the like, and the thermal decomposition becomes severe. Problems such as yellowing occur.

The intrinsic viscosity of the polyester of the present invention, particularly the polyester whose main repeating unit is composed of ethylene-2,6-naphthalate, is preferably 0.4.
The range is from 0 to 1.00 deciliter / gram, more preferably from 0.42 to 0.95 deciliter / gram, and even more preferably from 0.45 to 0.90 deciliter / gram. If the intrinsic viscosity is less than 0.40 deciliter / gram, the obtained molded article or the like has poor mechanical properties. Also 1.
If it exceeds 00 deciliters / gram, the resin temperature rises during melting by a molding machine or the like, and thermal decomposition becomes severe, free low-molecular-weight compounds that affect fragrance retention increase, or the molded product is colored yellow. Problems occur.

The polyester of the present invention is a polyester produced using a germanium compound as a catalyst.
a compound containing at least one element selected from the group consisting of 1, Si, Fe, Sr, Zr, Sn, W, and Pb;
0.001 to the acid component of the polyester as an element
To 0.5 mol%, preferably 0.003 to 0.3 mol%, more preferably 0.005 to 0.1 mol%, of the cyclic trimer when melted at a temperature of 290 ° C. for 60 minutes. The increase is 0.30% by weight or less, preferably 0.2% by weight or less, more preferably 0.1% by weight or less.

Further, the polyester of the present invention contains an alkali metal compound or an alkaline earth metal compound as an element in an amount of 0.001 to 0.001 to the acid component of the polyester.
1 mol%, preferably 0.003 to 0.5 mol%, more preferably 0.005 to 0.3 mol%.

In the present invention, the amount of increase of the cyclic trimer when melted at a temperature of 290 ° C. for 60 minutes is confirmed as follows. That is, the polyester chip is dried and heated and melted at 290 ° C. for 60 minutes under a nitrogen atmosphere.
It is calculated by the following equation. Cyclic trimer increase during melting (% by weight) = Cyclic 3 after melting
Monomer content (% by weight) -cyclic trimer content before melting (% by weight)

If the increase is 0.30% by weight or less, the stain on the mold at the time of molding is eliminated, and at the same time, the unpleasant taste and odor of the molded product are remarkably improved.

The amount of diethylene glycol copolymerized in the polyester of the present invention is preferably 1.5 to 5.0 mol%, more preferably 1.8 to 4.5 mol%, of the glycol component constituting the polyester. More preferably, it is 2.0 to 4.0 mol%. When the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability becomes poor,
The decrease in molecular weight during molding is large, and the acetaldehyde content and the formaldehyde content are undesirably large. When the content of diethylene glycol is less than 1.5 mol%, the transparency of the obtained molded article is deteriorated.

The acetaldehyde content of the polyester composition of the present invention is preferably 10 ppm or less, more preferably 8 ppm or less, further preferably 6 ppm.
Or less, particularly preferably 4 ppm or less, and the formaldehyde content is preferably 6 ppm or less, more preferably 5 ppm or less.
pm or less, more preferably 4 ppm or less. When the acetaldehyde content is 8 ppm or more and the formaldehyde content is 6 ppm or more, the contents such as containers molded from the polyester composition become poor in flavor and odor.

The content of the cyclic trimer of the polyester of the present invention is preferably 0.50% by weight or less, more preferably 0.45% by weight or less, further preferably 0.40% by weight or less. When a heat-resistant hollow molded article or the like is molded from the polyester composition of the present invention, heat treatment is performed in a heating mold. However, when the content of the cyclic trimer is 0.50% by weight or more, heating is performed. The adhesion of the oligomer to the surface of the mold is rapidly increased, and the transparency of the obtained hollow molded article or the like is extremely deteriorated.

The polyester of the present invention can be produced, for example, by the following steps, but the present invention is not limited to these production methods. That is, the polyester of the present invention is prepared by directly reacting terephthalic acid with ethylene glycol and, if necessary, the above-mentioned copolymerization component to distill water and esterify the mixture, and then reduce the pressure using a Ge compound as a polycondensation catalyst. A direct esterification method in which polycondensation is performed below, or dimethyl terephthalate was reacted with ethylene glycol and, if necessary, the above copolymerization component in the presence of a transesterification catalyst, was subjected to transesterification by distilling off methyl alcohol. Thereafter, a melt polycondensation step by a transesterification method in which polycondensation is mainly performed under reduced pressure using a Ge compound as a polycondensation catalyst, and the molten polycondensation prepolymer obtained in the above melt polycondensation step is solidified under an inert gas stream. It is produced through a solid phase polycondensation step of performing polycondensation in a phase state, and a water treatment step of treating the polycondensation polymer obtained in the solid phase polycondensation step with water. Al, Si, Fe, Sr, Zr, Sn,
A compound containing at least one element selected from the group consisting of W and Pb, or a compound thereof and an alkali metal compound or an alkaline earth metal compound in the esterification or transesterification step and / or the melt polycondensation step. Added.

The Ge compound used in the present invention includes:
Examples include amorphous germanium dioxide, crystalline germanium dioxide, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, and germanium phosphite. When a Ge compound is used, the amount of the Ge compound used is 3 to 100 ppm, preferably 5 to 100 ppm, more preferably 10 to 70 ppm as the amount of Ge remaining in the polyester resin.

Al, Si, Fe, S used in the present invention
Compounds containing at least one element selected from the group consisting of r, Zr, Sn, W, and Pb include carboxylate salts such as acetates, oxides, hydroxides, chlorides and carbonates of these elements. And a chelate compound with an inorganic acid salt, alkoxide, acetylacetonate, etc., which are added to the reaction system as a powder, an aqueous solution, an ethylene glycol solution, a slurry of ethylene glycol, or the like.

The alkali metal compound or alkaline earth metal compound used in the present invention includes carboxylate salts such as acetates of these elements, alkoxides and the like, and may be in the form of powder, aqueous solution, ethylene glycol solution or the like. It is added to the reaction system.

Various P compounds can be used as stabilizers. Examples of the P compound used in the present invention include phosphoric acid, phosphorous acid, and derivatives thereof. Specific examples include phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, dibutyl phosphate, and dibutyl phosphate. Phosphoric acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, etc., which may be used alone or in combination of two or more.
The P compound is 1 to 20 as a residual amount of P in the produced polymer.
It can be added at any stage of the polyester production reaction step so as to be in the range of 0 ppm.

The shape of the polyester chip may be any of a cylinder type, a square type, a flat plate shape and the like, and the size is usually in the range of 1.5 to 4 mm in height, width and height. For example, in the case of a cylinder type, the length is 1.
It is practical that the diameter is about 5 to 4 mm and the diameter is about 1.5 to 4 mm. Further, the weight of the chip is practically in the range of 15 to 30 mg / piece.

In the water treatment step, the solid phase polymerized polyester chip is subjected to a contact treatment with water, steam or a steam-containing gas. Examples of the hot water treatment method include a method of immersing in water and a method of spraying water on a chip with a shower.
The processing time is 5 minutes to 2 days, preferably 10 minutes to 1 day.
Days, more preferably 30 minutes to 10 hours, and the temperature of water is 20 to 180 ° C, preferably 40 to 150 ° C,
More preferably, it is 50 to 120 ° C.

The following is an example of a method for industrially performing water treatment, but the method is not limited thereto. The treatment method may be either a continuous method or a batch method, but the continuous method is preferable for industrial use.

In the case of treating the polyester chips with water in a batch system, a silo-type treatment tank may be used. That is, the chips of the polyester are received in the silo in a batch system and water treatment is performed. Alternatively, it is also possible to receive the polyester chips in a rotary cylindrical treatment tank and perform water treatment while rotating the chips to make the contact with water more efficient.

In the case of treating the polyester chips with water in a continuous manner, the polyester chips can be continuously or intermittently received from above in a tower type treatment tank and subjected to water treatment. This conceptual diagram is shown in FIG.

When the polyester chips are brought into contact with water vapor or a gas containing water vapor for treatment, 50 to 15
Steam or steam-containing gas or steam-containing air at a temperature of 0 ° C., preferably 50 to 110 ° C., is preferably supplied as a steam in an amount of 0.5 g or more per kg of granular polyethylene terephthalate or is present in the form of particulate polyethylene terephthalate. And steam. This contact between polyester chips and water vapor
The reaction is usually performed for 10 minutes to 2 days, preferably for 20 minutes to 10 hours.

The method of industrially carrying out the contact treatment of granular polyethylene terephthalate with water vapor or a gas containing water vapor is exemplified below, but is not limited thereto. The processing method may be either a continuous method or a batch method. When a polyester chip is subjected to a contact treatment with steam in a batch system, a silo-type treatment device may be used. That is, a polyester chip is received in a silo, and steam or a steam-containing gas is supplied in a batch system to perform a contact treatment. Alternatively, it is possible to receive the granular polyethylene terephthalate in a rotary cylinder type contact treatment device and perform the contact treatment while rotating the contact so as to make the contact more efficient.

When the polyester chips are continuously subjected to the contact treatment with steam, the granular polyethylene terephthalate is continuously received from above in a tower-type treatment apparatus, and the steam is continuously supplied in parallel or countercurrent to contact the steam with the steam. it can. As described above, when treated with water or steam, the granular polyethylene terephthalate is drained with a draining device such as a vibrating sieve or a Simon Carter, if necessary, and transferred to the next drying step.

The drying of the polyester chips which have been subjected to the contact treatment with water or steam can be carried out by a commonly used polyester drying treatment. As a method for continuous drying, a hopper-type through-air dryer that supplies polyester chips from the upper portion and allows the drying gas to flow from the lower portion is usually used. As a method for reducing the amount of drying gas and drying efficiently, a rotary disk-type continuous dryer is used. Heating steam, heating medium, etc. are supplied to the rotating disk and the outer jacket while passing a small amount of drying gas. The polyester chips can be indirectly heated and dried.

As a dryer for drying in a batch mode, a double cone type rotary dryer is used, and the drying can be performed under vacuum or while passing a small amount of drying gas under vacuum. Alternatively, the drying may be performed while passing a drying gas under atmospheric pressure.

The dry gas may be atmospheric air, but dry nitrogen and dehumidified air are preferred from the viewpoint of preventing the molecular weight from being reduced by hydrolysis or thermal oxidative decomposition of the polyester.

In the polyester production process, in the step of chipping the melt polycondensation polymer, in the solid phase polymerization step, and in the step of transporting the melt polycondensation polymer chip and the solid phase polymerization polymer chip, etc., it was originally set at the time of granulation. Particles, powder, etc., which are considerably smaller than chips of a size are generated. Here, such fine particles and powder having the same composition as the polyester chips are referred to as fine. In the process of producing polyester, high-purity raw materials and auxiliary materials are used, and at the same time, filtration of molten polycondensation polymer, filtration of cooling water for polyester chips, filtration of water introduced from outside the system for water treatment of chips, and said chips Since measures are taken to prevent foreign substances and foreign substances other than the polyester used from being mixed in by filtering the gas used for transporting and the like, the fine can be free of foreign substances and foreign substances other than polyester. .

The content of such fines in the polyester is preferably 0.1 to 300 ppm, more preferably 0.2 to 250 ppm. 0.1p
In the case of less than pm, the crystallization speed becomes very slow, the crystallization of the plug portion of the hollow molded body becomes insufficient, and the shrinkage amount of the plug portion does not fall within the specified value range, thus resulting in poor capping. In addition, the stretch heat setting mold for molding the heat-resistant hollow molded article is heavily soiled, and the mold must be cleaned frequently to obtain a transparent hollow molded article.
When the content exceeds 300 ppm, the crystallization rate is increased, and the crystallization of the plug portion of the hollow molded article becomes excessive. Therefore, the shrinkage amount of the plug portion does not fall within the specified value range, so that the capping of the plug portion is performed. It becomes defective, causing leakage of the contents, and whitening of the preform for hollow molding, making normal stretching impossible.

In the present invention, the intrinsic viscosity of the fine polyester is usually 0.55 to 0.90, preferably 0.57 to 0.88, more preferably 0.58 to 0.88.
0.87. When the intrinsic viscosity is less than 0.55, the transparency of the obtained molded body is deteriorated, and the shrinkage of the plug portion becomes too large. The intrinsic viscosity is preferably the same as the intrinsic viscosity of the PET chip, or the intrinsic viscosity is 0.03 higher than the intrinsic viscosity of the PET chip. The same composition as the polyester chip means that the fine copolymerization component and the content of the copolymerization component are the same as the polyester chip.

In the present invention, as a method for adjusting the fine content of the polyester to the above-mentioned range, a step of sieving a PET resin chip having a high fine content, which has not been passed through a sieving step, and a fine removing step by an air flow. In addition to mixing PET resin chips with a very small fine content at an appropriate ratio, it can also be adjusted by changing the opening of the decoration in the fine removal process, and changing the sieving speed Any method such as the method described above can be used.

When the polyester chips are treated with water as described above, the following method is practical.
That is, first, in the water treatment step, it is preferable that at least a part of the water to be treated is water that is discharged from the treatment tank, returned to the treatment tank again, and used repeatedly. By reusing water, it is possible to control the amount of fine powder in the treated water, and it is easy to control the fine content of the polyester. When water having a fine powder amount of 0 is used for water treatment, fines adhering to the polyester chips may be washed away by water and may fall below 0.1 ppm. Further, the amount of fine powder in the treated water is 1000 ppm or less, preferably 500 ppm.
It is preferable to carry out while adjusting as follows. If water having a fine powder content of more than 1000 ppm is used, the fine content of the polyester may exceed 300 ppm.

It is also possible to simultaneously use a saturated fatty acid monoamide, an unsaturated fatty acid monoamide, a saturated fatty acid bisamide, an unsaturated fatty acid bisamide and the like with the polyester of the present invention.

Examples of the saturated fatty acid monoamide include lauric amide, palmitic amide, stearic amide, behenic amide and the like. Examples of unsaturated fatty acid monoamides include oleic acid amide, erucic acid amido ricinoleic acid amide, and the like. Examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid Amides and the like. Examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide and hexamethylene bisoleic acid amide. Preferred amide compounds are saturated fatty acid bisamide, unsaturated fatty acid bisamide and the like. The compounding amount of such an amide compound is 1
The range is from 0 ppb to 1 × 10 ⁵ ppm.

Metal salt compounds of aliphatic monocarboxylic acids having 8 to 33 carbon atoms, such as naphthenic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid,
Stearic acid, behenic acid, montanic acid, melicic acid,
Lithium, sodium, potassium, magnesium, calcium, and cobalt salts of saturated and unsaturated fatty acids such as oleic acid and linoleic acid can be used in combination. The compounding amount of these compounds is 10p
The range is from pb to 300 ppm.

The polyester of the present invention can be preferably used as a hollow molding, a tray, a packaging material such as a biaxially stretched film, a film for coating a metal can, and the like. Also,
The polyester of the present invention can also be used as one constituent layer of a multilayer molded article or a multilayer film.

The polyester of the present invention may contain a known ultraviolet absorber, a lubricant added from the outside or a lubricant internally deposited during the reaction, a release agent, a nucleating agent, a stabilizer, an antistatic agent, a pigment, if necessary. And various other additives.

[0063]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. In addition, the measuring method of the main characteristic value in this specification is demonstrated below.

(1) Intrinsic viscosity (IV) of polyester: It was determined from the solution viscosity at 30 ° C. in a 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio) mixed solvent.

(2) Polyethylene diethylene glyco-
The content was determined by decomposing with methanol and quantifying the amount of DEG by gas chromatography and expressed as a ratio (mol%) to the total glycol components.

(3) Density The density was measured at 30 ° C. using a density gradient tube of a mixed solvent of calcium nitrate / water.

(4) Polyester cyclic trimer content (hereinafter referred to as "CT content") A sample (300 mg) was dissolved in 3 ml of a hexafluoroisopropanol / chloroform mixed solution (volume ratio = 2/3). Further, 30 ml of chloroform is added for dilution.
To this, 15 ml of methanol was added to precipitate a polymer, followed by filtration. The filtrate was evaporated to dryness, the volume was adjusted to 10 ml with dimethylformamide, and the cyclic trimer was quantified by high performance liquid chromatography.

(5) Increase in amount of cyclic trimer during melting of polyester (ΔCT amount) 3 g of dried polyester chip was placed in a glass test tube, immersed in an oil bath at 290 ° C. for 60 minutes under a nitrogen atmosphere, and melted. Let it. The amount of increase of the cyclic trimer at the time of melting is determined by the following equation. Cyclic trimer increase during melting (% by weight) = Cyclic 3 after melting
Monomer content (% by weight) -cyclic trimer content before melting (% by weight)

(6) Acetaldehyde content of polyester (hereinafter referred to as "AA content") A sample / distilled water = 1 g / 2 cc placed in a glass ampoule purged with nitrogen is sealed and extracted at 160 ° C. for 2 hours. After the treatment and cooling, the acetaldehyde in the extract was measured by high-sensitivity gas chromatography, and the concentration was expressed in ppm.

(7) Measurement of Fine Content About 0.5 kg of resin was placed on a sieve (diameter 30 cm) with a wire mesh having a nominal size of 1.7 mm according to JIS-Z8801, and 0.1% of cation was added from the top. An aqueous solution of an aqueous solution of a surfactant (alkyltrimethylammonium chloride) was sieved for 1 minute at a total amplitude width of about 7 cm and 60 reciprocations / 1 minute while being showered at a flow rate of 2 L / min. This operation was repeated, and the resin was sieved in a total of 10 to 30 kg. The fines removed by filtration were collected by filtration with a 1G1 glass filter manufactured by Iwaki Glass Co., Ltd. together with a surfactant aqueous solution, and washed with ion-exchanged water. Put this together with the glass filter in a dryer for 1
After drying at 00 ° C. for 2 hours, the mixture was cooled and weighed. The same operation of washing and drying with ion-exchanged water was repeated again to confirm that the weight became constant, and the weight of the glass filter was subtracted from this weight to obtain a fine weight. Fine content is
Fine amount / total weight of resin sieved.

(8) Evaluation of mold stain The polyester composition was dried with a drier using nitrogen, and a preform was molded at a resin temperature of 290 ° C. using an M-150C (DM) injection molding machine manufactured by Meiki Seisakusho. After the plug portion of this preform was heated and crystallized by a home-made plug portion crystallizer, biaxial stretch blow molding was performed using an LB-01 stretch blow molding machine manufactured by Co-Poplast Co.
The resultant was heat-set in a mold set at a temperature of 10 ° C. for 10 seconds to obtain a 500 cc hollow molded body. Under the same conditions, continuous stretch blow molding was performed, and the stain on the mold was evaluated by the number of moldings until the transparency of the container was impaired by visual inspection. In addition, as a sample for haze measurement, a body portion of a container after continuous molding 8,000 times was provided.

(9) Haze (haze degree%) Body (thickness: about 0.40 mm) of the hollow molded article of (8) above
A sample was cut out from the sample and a haze meter manufactured by Nippon Denshoku
Was measured.

(10) The amount of fine powder (pp
m) 1000 cc of treated water passed through a JIS standard 20 mesh filter was collected from the treated water outlet of the treatment tank.
After filtration with a 1G1 glass filter manufactured by Iwaki Glass Co., Ltd., 100
After drying at room temperature for 2 hours and cooling at room temperature, the weight is measured and calculated.

(Example 1) A slurry of high-purity terephthalic acid and ethyl glycol was continuously supplied to a first esterification reactor containing a reactant in advance, and stirred for about 2 hours.
The reaction was carried out at 50 ° C. and 0.5 kg / cm ² G for an average residence time of 3 hours. This reaction product was sent to the second esterification reactor, and reacted at a temperature of about 260 ° C. and 0.05 kg / cm ² G to a predetermined reactivity under stirring. In addition, crystalline germanium dioxide was dissolved in water by heating, ethylene glycol was added thereto, and a heat-treated catalyst solution, aluminum acetylacetonate ethylene glycol solution and phosphoric acid ethylene glycol solution were separately separated. It was continuously fed to this second esterification reactor. This esterification reaction product is continuously supplied to the first polycondensation reactor, and is stirred at about 265 ° C.
The polycondensation is carried out at 25 torr for 1 hour, then at about 265 ° C. for 3 hours with stirring in the second polycondensation reactor, and for about 1 hour at about 275 ° C. and 0.5 to 1 torr with stirring in the final polycondensation reactor. Was. The polycondensation reaction product was formed into chips, and subsequently crystallized at about 155 ° C under a nitrogen atmosphere, preheated to about 200 ° C under a nitrogen atmosphere, and then sent to a continuous solid-state polymerization reactor to be solidified at about 205 ° C under a nitrogen atmosphere. Polymerized. After the solid phase polymerization, fine treatment was continuously performed in a sieving process and a fine removing process to remove fines. The intrinsic viscosity of the obtained PET was 0.74 deciliter / gram, the content of the cyclic trimer was 0.30% by weight, and the density was 1.430 g / cm ³ .

GAF filter bag PE manufactured by ISP
-1P2S (polyester felt, filtration accuracy 1μm)
A device (9) for removing particles in water is installed, and an inlet (8) for ion-exchanged water via this device (9), a raw material chip supply port (1) at the top of the processing tank, and an upper limit of the processing water in the processing tank. The overflow outlet located at the level (2), the outlet for the mixture of polyester chips and treated water at the bottom of the treatment tank (3), the treated water discharged from the overflow outlet, and the treated water discharged from the bottom of the treatment tank The treated water passed through the polyester chip drainer (continuous centrifugal separator) (4) passes through the filter device (5), which is a 30-μm belt-type filter made of paper, and returns to the water treatment tank. A feed pipe (6), an inlet (7) for the finely-removed treated water, and an adsorption tower (1) for adsorbing acetaldehyde, glycol, etc. in the finely-removed treated water.
The PET chips described above were treated with water using a 500-liter tower-type treatment tank shown in FIG.
PET chips are transferred to a water treatment tank controlled at a treatment water temperature of 95 ° C. at a rate of 50 kg / hour at the top of the treatment tank (1).
Started continuous feeding from. Five hours after the start of the charging, the PET chips are taken out from the lower part (3) of the water treatment tank together with the treated water at a rate of 50 kg / hour while continuing to charge the PET chips into the water treatment tank. The treated water that had passed through the continuous centrifugal dehydrator (4) used was returned to the water treatment tank again via the filtration device (5), and repeated use was started. The amount of fine powder in the treated water discharged from the treatment tank was about 30 ppm.

Water-treated PET after continuous operation for 100 hours
Has an intrinsic viscosity of 0.74 deciliter / gram, a DEG content of 2.5 mol%, an AA content of 2.9 ppm, a cyclic trimer content of 0.30% by weight, and an increase of the cyclic trimer. Was 0.01% by weight, and the fine content was about 5 ppm. The residual amount of Ge measured by atomic absorption analysis was 0.0106 mol% (about 40 ppm based on 1 ton of PET) with respect to the acid component, and the residual amount of Al was 0.00.0 mol% with respect to the acid component.
107 mol% (about 15 ppm based on 1 ton of PET),
The residual amount of P is 0.0186 mol% based on the acid component (PET
(About 30 ppm per ton). The haze of the container obtained by the method (8) using this PET is 1.1%.
Shows excellent transparency. In addition, the number of moldings up to the mold contamination was 13,000, which was no problem. The AA content of the bottle was 18.6 ppm, which was a problem-free value.

(Comparative Example 1) The amount of increase in cyclic trimer measured without subjecting the solid-phase polycondensed PET obtained in Example 1 to hot water treatment was 0.58% by weight, which was a very high value. there were. Further, the haze of the container obtained by the method (8) was as bad as 8.7%, and the number of moldings until the mold was stained was as low as 3000 times.

Comparative Example 2 PET was obtained in the same manner as in Example 1 except that aluminum acetylacetonate was not added. The intrinsic viscosity of PET is 0.
74 deciliters / gram, DEG content 2.7 mol%, AA content 3.2 ppm, cyclic trimer content 0.30 wt%, cyclic trimer increase 0.07 wt% The fine content was about 5 ppm. Also,
The haze of the container obtained by the method (8) was as bad as 5.8%, and the number of moldings until the mold was soiled was as low as 7000 times. The residual amount of Ge measured by atomic absorption spectrometry was 0.0107 mol% with respect to the acid component (about 40 ppm based on 1 ton of PET), and the residual amount of P was 0.01% with respect to the acid component.
89 mol% (about 31 ppm based on 1 ton of PET).

[0079]

According to the polyester of the present invention, contamination of a molding die is hardly generated by further suppressing the increase of the cyclic trimer at the time of melting during injection molding, the transparency is high, and the heat resistance dimensional stability is improved. An excellent hollow molded article can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus used for a method for producing a polyester of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Raw material chip supply port 2 Overflow discharge port 3 Polyester chip and treated water discharge port 4 Drainer 5 Fine remover 6 Pipe 7 Treated water inlet 8 Ion-exchanged water inlet 9 Particle remover 10 Adsorption tower

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08G 63/85 C08G 63/85 63/88 63/88 // B29K 7:00 B29K 7:00 67:00 67:00 F term (reference) 4F207 AA24 AA25 AB16 AG01 AG07 AH54 AH55 AH56 AH58 KA04 KA17 KF01 KL84 KW41 4J029 AA03 AB01 AB07 AC01 AC02 AD01 AE01 AE03 BA03 BA04 BA05 BD07A CB06A CB10 J03 CB12B01 J03 CB12B01

Claims (12)

[Claims] 1. A polyester produced using a germanium compound as a catalyst, comprising: Al, Si, Fe, Sr,
A compound containing at least one element selected from the group consisting of Zr, Sn, W, and Pb is contained as an element in an amount of 0.001 to 0.5 mol% with respect to an acid component of the polyester;
A polyester, wherein the amount of increase of the cyclic trimer when melted at a temperature of 290 ° C. for 60 minutes is 0.30% by weight or less. 2. The polyester according to claim 1, wherein the alkali metal compound or the alkaline earth metal compound is contained as an element in an amount of 0.001 to 1 mol% based on the acid component of the polyester. 3. The content of the copolymerized diethylene glycol in the glycol component constituting the polyester is as follows.
The polyester according to claim 1 or 2, wherein the amount of the polyester is 5 to 5.0 mol%. 4. An acetaldehyde content of 10 ppm
The polyester according to claim 1, wherein: 5. A polyester comprising a polyester chip and a fine polyester of the same composition as the polyester chip.
The polyester according to any one of claims 1 to 4, wherein the polyester is a mixture with the polyester. 6. The polyester according to claim 1, wherein the polyester is a linear polyester containing 95 mol% or more of ethylene terephthalate as a main repeating unit.
Polyester according to the above. 7. A polyester comprising 90 mol% of ethylene-2,6-naphthalate as its main repeating unit.
The polyester according to any one of claims 1 to 5, which is a linear polyester containing the above. 8. The polyester formed into chips after polycondensation is treated in a treatment tank with treated water satisfying the following conditions (a) and (b): Item 10. The polyester according to any one of Items 1 to 7. (A) Temperature of 40 to 120 ° C (b) Treated water including wastewater from the treatment tank 9. The polyester formed into chips after polycondensation is treated with treated water satisfying the following condition (c) in a treatment tank. Polyester according to the above. (C) Treated water having a polyester fine powder content of 1000 ppm or less 10. A hollow molded article comprising the polyester according to claim 1. Description: 11. A sheet-like material obtained by extruding the polyester according to claim 1. 12. A stretched film obtained by stretching the sheet material according to claim 11 in at least one direction.