JP2003313413A - Polyester composition and blow molding sheet material and oriented film therefrom - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester composition excellent in crystallinity controllability upon melt forming and long-term continuous moldability, and also to provide a blow molding, a sheet material and an oriented film obtained therefrom which is excellent in transparency and dimension stability under heating, particularly a contraction coefficient at a mouth plug site of the blow molding falling within an appropriate range and further can give a container for a liquid in which remaining off-flavor and off-taste are hardly generated. <P>SOLUTION: The polyester composition comprises polyester chips comprising ethylene terephthalate as the main repeating unit and 0.1-5,000 ppm of polyester fines having the same composition as the above polyester chips and the composition shows 170-195°C of a crystallization temperature (Tc1') measured by a differential scanning calorimeter (DSC) upon temperature rising of the fines. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composition and a hollow molded article, a sheet-like material and a stretched film comprising the same, and particularly to crystallization controllability during melt molding and long-term continuous moldability. Excellent polyester composition and molded articles and sheets excellent in transparency and heat-resistant dimensional stability
And a stretched film.

[0002]

2. Description of the Related Art A polyester whose main repeating unit is ethylene terephthalate (hereinafter sometimes abbreviated as PET resin) is a carbonated beverage due to its excellent transparency, mechanical strength, heat resistance, gas barrier property and the like. It has been used as a material for containers such as juice, juice and mineral water, and its spread is remarkable. In these applications, a polyester bottle is hot-filled with a beverage sterilized at high temperature, or is sterilized at high temperature after filling the beverage, but in a normal polyester bottle, shrinkage occurs during such heat-filling treatment. Deformation occurs and becomes a problem. As a method for improving the heat resistance of a polyester bottle, there has been proposed a method in which a bottle mouth plug is heat-treated to increase the crystallinity, or a stretched bottle is heat-fixed.
In particular, if the crystallization of the spout is insufficient or the crystallinity varies greatly, the sealing property with the cap may deteriorate and the contents may leak.

In order to improve the heat resistance of the body of the bottle, for example, as shown in Japanese Patent Publication No. 59-6216, a method of heat treatment by increasing the temperature of the stretching blow mold is adopted. For bottles used for applications that undergo heat sterilization treatment at high temperatures, use of PET resin with a high crystallization rate yields only heat-treated bottles with poor transparency and large fluctuations in crystallinity at the spout. I can't. In particular, when a defective product generated in a molding factory or a recovered product of a used bottle is reused as a part of a bottle molding material, the crystallization property of the virgin raw material becomes a problem. Such a problem frequently occurs in a large-sized bottle having a capacity of 1.5 liters or more because the wall thickness becomes large.

Further, when a large number of bottles are molded by using the same mold by such a method, the bottles obtained with long-time operation are whitened and the transparency is lowered, and only bottles having no commercial value are obtained. You won't get it. It was found that this is because deposits due to the PET resin were attached to the mold surface, resulting in mold stains, which were transferred to the surface of the bottle. In particular, in recent years, the molding speed has been increased for the purpose of reducing the cost at the time of bottle production, and the mold contamination has become a greater problem from the viewpoint of productivity.

Further, in the case of a content liquid such as a fruit juice drink which needs to be hot filled, a method of crystallizing the mouth part of the preformed or molded bottle by heat treatment (Japanese Patent Laid-Open No. 55-79237). JP-A No. 58-110221, etc.) is generally used. In such a method, that is, a method of heat-treating the plug portion and the shoulder portion to improve heat resistance, the time and temperature of the crystallization treatment greatly affect the productivity, and the treatment can be performed at a low temperature in a short time. It is preferable that the PET resin has a high conversion rate. On the other hand, the body is required to be transparent even when subjected to heat treatment during molding so as not to deteriorate the color tone of the filler.
Opposite characteristics are required for the spout and body.

[0006]

Various proposals have been made to solve such problems. For example, a method of adding an inorganic nucleating agent such as kaolin and talc to polyethylene terephthalate (JP-A-56-2342, JP-A-56-21832), a method of adding an organic nucleating agent such as a montanic acid wax salt. (Japanese Patent Laid-Open No. 57-125246 and Japanese Patent Laid-Open No. 57-207639), but these methods have problems in practical use because of the generation of foreign matter and cloudiness. In addition, a method of inserting a heat-resistant resin piece into the plug portion (Japanese Patent Laid-Open No. 61-259946 and Japanese Patent Laid-Open No. 2-2).
No. 69638) has been proposed, but the bottle productivity is poor and the recyclability is also a problem.

Further, a method for modifying the crystallization rate of PET by bringing a PET chip into contact with a polyethylene member under flowing conditions (Japanese Patent Laid-Open No. 9-71639), and polypropylene resin or polyamide resin under the same conditions. A method for modifying the crystallization rate of PET by bringing it into contact with a member made of (JP-A-11-209492), and a polyester resin composition in which a polyester resin is mixed with polyethylene of 0.1 to 45 ppb (JP-A-9-151308). However, it has been found that it is very difficult to obtain a stable crystallization rate and transparency even by using such a method or composition.

The present invention solves the above-mentioned problems of the prior art, and a polyester composition excellent in crystallization control during melt molding and long-term continuous moldability, and transparency and heat resistance obtained therefrom. Good dimensional stability, in particular, the shrinkage rate of the plug portion of the hollow molded article is within an appropriate range, and the resulting molded article is unlikely to have residual off taste or offensive odor. The purpose is to provide a stretched film.

[0009]

To achieve the above object, the polyester composition of the present invention comprises a polyester chip whose main repeating unit is ethylene terephthalate, and a polyester chip of the same composition as the polyester chip. A polyester composition consisting of 0.1 to 5000 ppm of fines, wherein the fines have a crystallization temperature (Tc1 ') at elevated temperature measured by DSC (Differential Scanning Calorimeter).
Is in the range of 170 to 195 ° C., which is a polyester composition.

In this case, the content of the polyester film having the same composition as that of the polyester chip may be 10 ppm or less. Here, fine means a nominal size of 1.7 mm according to JIS-Z8801.
Means fine polyester powder that has passed through a wire mesh sieve, and a film-like material means two of the polyesters remaining on the wire mesh sieve having a nominal size of 5.6 mm according to JIS-Z8801. The above film means a film-like product having a thickness of about 0.5 mm or less after removing the chip-like product which is fused or cut into pieces larger than the normal shape, and the content thereof is measured by the following measuring method. To measure by.

Further, as described below, the crystallization temperature (Tc1 ') of the fine particles during heating is measured by a differential scanning calorimeter (DSC). The crystallization peak temperature observed at the time of the temperature rise in the DSC measurement is called the crystallization temperature at the time of temperature rise (Tc1 ′). This crystallization peak is usually one, but is composed of two peaks. There is. In the present invention, in such a case, the crystallization peak temperature on the high temperature side is referred to as “fine temperature rising crystallization temperature (Tc1 ′)”.

In this case, 60 at a temperature of 290.degree.
The cyclic trimer increment when melted for minutes can be 0.50 wt% or less.

In this case, the content of cyclic trimer is
It can be up to 0.7% by weight.

The polyester composition of the present invention comprises, in addition to the above polyester composition, at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin and a polyacetal resin, 0.1 ppb-500.
It is characterized by being mixed with 00 ppm.

In this case, the hollow molded body is
It can be formed by molding the polyester composition described above.

Further, in this case, the sheet-like material is
It can be formed by molding the polyester composition described above.

Furthermore, in this case, the stretched film may be formed by stretching a sheet-like material in at least one direction.

The above-mentioned polyester composition of the present invention is less likely to cause mold stains during molding, has excellent crystallization controllability of the spout, and has excellent transparency, heat resistance, mechanical properties and residual properties. A hollow molded article, a sheet-like material and a stretched film having little off-taste and off-flavor and excellent in aroma retention are provided.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiments of the polyester composition of the present invention, and the hollow molded article, sheet-like material and stretched film comprising the same will be specifically described below.

The polyester according to the present invention is a polyester whose main repeating unit is ethylene terephthalate, preferably 8 units of ethylene terephthalate units.
It is a linear polyester containing 5 mol% or more, more preferably 90 mol% or more, and particularly preferably 95% mol or more.

As the dicarboxylic acid as a copolymerization component used when the polyester is a copolymer,
Aromatic dicarboxylic acids such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid and their functional derivatives, p-oxybenzoic acid, oxycaproic acid, etc. Oxyacids and their functional derivatives, adipic acid, sebacic acid, succinic acid, glutaric acid and other aliphatic dicarboxylic acids and their functional derivatives, cyclohexanedicarboxylic acid and other aliphatic dicarboxylic acids and their functional derivatives, etc. .

The glycol used as a copolymerization component when the polyester is a copolymer is diethylene glycol or 1,3-trimethylene glycol.
, Tetramethylene glycol, neopentyl glyco-
Alicyclic glycol such as cyclohexyl dimethanol, aromatic glycol such as bisphenol A, alkylene oxide adduct of bisphenol A, polyethylene glycol, etc. Polybutylene glyco
Examples thereof include polyalkylene glycol such as alcohol.

Further, as the polyfunctional compound as a copolymerization component used when the polyester is a copolymer, examples of the acid component include trimellitic acid and pyromellitic acid. Examples of the component include glycerin and pentaerythritol. The amount of the above copolymerization component used should be such that the polyester maintains a substantially linear shape. Further, a monofunctional compound such as benzoic acid or naphthoic acid may be copolymerized.

The above-mentioned polyester is obtained by directly reacting terephthalic acid with ethylene glycol and optionally the above-mentioned copolymerization component to distill off water to esterify it, and then use an antimony compound, germanium compound, aluminum as a polycondensation catalyst. Compound or a direct esterification method in which polycondensation is performed using one or more compounds selected from titanium compounds under reduced pressure, or dimethyl terephthalate and ethylene glycol and, if necessary, the above-mentioned copolymerization component as an ester exchange catalyst In the presence of a solvent to distill off methyl alcohol and transesterify, and then use one or more compounds selected from antimony compounds, germanium compounds, titanium compounds or aluminum compounds as polycondensation catalysts. Manufactured by the transesterification method, which mainly involves polycondensation under reduced pressure. That.

As the above-mentioned starting materials dimethyl terephthalate, terephthalic acid or ethylene glycol,
Virgin dimethyl terephthalate derived from paraxylene, terephthalic acid or ethylene glycol derived from ethylene, as well as dimethyl terephthalate and terephthalic acid recovered from used PET bottles by a chemical recycling method such as methanol decomposition or ethylene glycol decomposition. A recovered raw material such as bishydroxyethyl terephthalate or ethylene glycol can also be used as at least a part of the starting material. The quality of the recovered raw material is a purity according to the purpose of use,
It goes without saying that it must be refined to quality.

Further, solid phase polymerization may be carried out in order to increase the molecular weight of the polyester resin and reduce the acetaldehyde content. In order to accelerate crystallization before solid-phase polymerization, the molten polycondensed polyester may be adsorbed with moisture and then crystallized by heating, or steam may be directly blown onto the polyester chips to be crystallized by heating.

First, the above-mentioned polyester to be subjected to solid-phase polymerization is 100 to 21 under an inert gas or under reduced pressure or in a steam or steam-containing inert gas atmosphere.
It is pre-crystallized by heating at a temperature of 0 ° C. for 1 to 5 hours. Then, under an inert gas atmosphere or under reduced pressure, 190 to 230
Solid phase polymerization is performed at a temperature of ° C for 1 to 30 hours.

The melt polycondensation reaction may be carried out in a batch reaction apparatus or a continuous reaction apparatus.
In any of these methods, the melt polycondensation reaction may be carried out in one step or may be carried out in multiple steps. The solid phase polymerization reaction can be carried out by a batch type apparatus or a continuous type apparatus as in the melt polycondensation reaction. The melt polycondensation and solid phase polymerization may be carried out continuously or may be carried out separately.

The antimony compound used for producing the polyester according to the present invention includes antimony trioxide, antimony acetate, antimony tartrate, antimony potassium tartrate, antimony oxychloride, antimony glycolate,
Examples thereof include antimony pentoxide and triphenylantimony. The antimony compound is added so that the residual amount of antimony in the produced polymer is in the range of 50 to 250 ppm.

The germanium compound used for producing the polyester according to the present invention includes amorphous germanium dioxide, crystalline germanium dioxide, germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetraoxide. Examples include -n-butoxide and germanium phosphite. When using a germanium compound, the amount used is 5 as the amount of germanium remaining in the polyester.
-150 ppm, preferably 10-100 ppm, more preferably 15-70 ppm.

As the titanium compound used in the method for producing the polyester of the present invention, tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate and tetra-n-butyl titanate and their partial hydrolysates are used. , Titanium acetate, titanyl oxalate, titanyl ammonium oxalate, sodium titanyl oxalate, potassium titanyl oxalate, calcium titanyl oxalate, titanyl oxalate compounds such as titanyl strontium oxalate, titanium trimellitate,
Titanium sulfate, titanium chloride, hydrolyzate of titanium halide, titanium oxalate, titanium fluoride, potassium hexafluorotitanate, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, Examples include titanium acetylacetonate.

Specific examples of the aluminum compound used for producing the polyester according to the present invention include aluminum formate, aluminum acetate, basic aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, Carboxylates such as aluminum stearate, aluminum benzoate, aluminum trichloroacetate, aluminum lactate, aluminum citrate, aluminum salicylate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, polyaluminum chloride, aluminum nitrate, aluminum sulfate, carbonic acid. Inorganic acid salts such as aluminum, aluminum phosphate, aluminum phosphonate,
Aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum iso-
Aluminum alkoxides such as propoxide, aluminum n-butoxide, aluminum t-butoxide, aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethylacetoacetate diiso-propoxide and other aluminum chelate compounds, trimethylaluminum, triethylaluminum. Examples thereof include organoaluminum compounds and partial hydrolysis products thereof, aluminum oxide and the like. Of these, carboxylates, inorganic acid salts and chelate compounds are preferable, and among these, basic aluminum acetate, aluminum lactate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, polyaluminum chloride and aluminum acetylacetonate are particularly preferable. preferable. The aluminum compound is added so that the residual amount of aluminum in the produced polymer is in the range of 5 to 200 ppm.

These catalyst compounds can be used, for example, as an ethylene glycol solution in any stage during the transesterification step or after the end of the transesterification reaction to the start of the polycondensation reaction,
Alternatively, it can be added during the esterification step or at any stage from the end of the esterification reaction to the start of the polycondensation reaction.

Further, the polyester composition of the present invention may contain at least one metal compound selected from the group consisting of alkali metal compounds and alkaline earth metal compounds. The alkali metal or alkaline earth metal is preferably at least one selected from lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium and barium, and the alkali metal or a compound thereof is preferable. More preferable. When using an alkali metal or a compound thereof, it is particularly preferable to use lithium, sodium or potassium. Examples of compounds of alkali metals and alkaline earth metals include formic acid, acetic acid, and
Propionic acid, butyric acid, saturated aliphatic carboxylates such as oxalic acid, unsaturated aliphatic carboxylates such as acrylic acid and methacrylic acid, aromatic carboxylates such as benzoic acid, halogen-containing carboxylates such as trichloroacetic acid, Hydroxycarboxylic acid salts such as lactic acid, citric acid, salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, hydrogen phosphate, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid, Inorganic acid salts such as bromic acid, 1-propanesulfonic acid, 1-pentanesulfonic acid, organic sulfonic acid salts such as naphthalenesulfonic acid, organic sulfates such as lauryl sulfuric acid, methoxy, ethoxy, n-propoxy, iso-
Examples thereof include alkoxides such as propoxy, n-butoxy and tert-butoxy, chelate compounds with acetylacetonate, hydrides, oxides and hydroxides. Alkali metal compounds or alkaline earth metal compounds are used as the residual amount of these elements in the produced polymer in the range of 1 to
Add so that it is in the range of 50 ppm.

These alkali metal compounds and alkaline earth metal compounds can be added to the reaction system at any stage of the polymerization reaction. For example, it can be added to the reaction system at any stage before and during the esterification reaction or transesterification reaction or immediately before the start of the polycondensation reaction or at any stage during the polycondensation reaction.

The above-mentioned alkali metal compound or alkaline earth metal compound is added to the reaction system as a powder, an aqueous solution, an ethylene glycol solution or the like.

Furthermore, the polyester composition of the present invention comprises a metal containing at least one element selected from the group consisting of silicon, manganese, iron, cobalt, zinc, gallium, strontium, zirconium, tin, tungsten and lead. It may contain a compound.

Examples of these metal compounds include saturated aliphatic carboxylates such as acetates, unsaturated aliphatic carboxylates such as acrylates, aromatic carboxylates such as benzoic acid, trichloroacetic acid and the like. Halogen-containing carboxylate, hydroxycarboxylate such as lactate, inorganic acid such as carbonate, organic sulfonate such as 1-propanesulfonate, organic sulfate such as laurylsulfate, oxide, and hydroxyl Compounds, chlorides, alkoxides, acetylacetonates and the like chelate compounds, which are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries and the like. These metal compounds are added so that the residual amount of the elements of these metal compounds per ton of the polymer produced is in the range of 0.05 to 3.0 mol.

Further, various P compounds can be used as the stabilizer. Examples of the P compound used in the present invention include phosphoric acid compounds, phosphorous acid compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphines. System compounds. Specific examples include phosphoric acid, phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tributyl ester, phosphoric acid triphenyl ester, phosphoric acid monomethyl ester, phosphoric acid dimethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, Phosphoric acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, methylphosphonic acid, methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, phenylphosphonic acid Diphenyl ester, dimethyl benzylphosphonate, diethyl benzylphosphonate, diphenylphosphinic acid, methyl diphenylphosphinate, phenylphenylphenylphosphinate , Phenyl phosphinic acid, methylphenyl phosphinic acid, phenyl phosphinic acid, diphenyl phosphine oxide, methyl diphenyl phosphine oxide, and triphenylphosphine oxide and the like,
These may be used alone or in combination of two or more. The P compound is added at any stage of the above-mentioned polyester forming reaction step so that the amount of P remaining in the produced polymer is in the range of 5 to 100 ppm.

Further, metal compounds other than the above can also be used within a range that does not affect the characteristics of the polyester composition of the present invention. Specific examples include copper, boron, indium, hafnium, niobium, tantalum, bismuth,
Examples thereof include oxides, halides, hydroxides, carbonates, sulfates, alkoxides and aliphatic or aromatic carboxylates of chromium, molybdenum, tellurium, nickel and the like.

Further, a basic nitrogen compound can be used in the production of the polyester according to the present invention. The basic nitrogen compound may be any of aliphatic, alicyclic, aromatic and heterocyclic nitrogen compounds. Specific examples include triethylamine, tributylamine, dimethylaniline, dimethylaniline, pyridine, quinoline,
Examples thereof include dimethylbenzylamine, piperidine, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, triethylbenzylammonium hydroxide, imidazole, and imidazoline. These compounds may be used in a free form, or may be used as a salt of a lower fatty acid or TPA. The addition of these basic nitrogen compounds to the reaction system can be appropriately selected at any stage until the completion of the initial polycondensation reaction, and they may be used alone or in combination of two or more. Good.

The blending amount of these basic nitrogen compounds is 0.01 to 1 mol%, preferably 0.0
It is 5 to 0.7 mol%, more preferably 0.1 to 0.5 mol%. 0.01 mol% of basic nitrogen compound
When it is less than 1, the transparency of the obtained hollow molded article from the polyester, particularly the stretch-heat-fixed hollow molded article, becomes extremely poor. Further, if it exceeds 1 mol%, the color tone of the polyester becomes poor.

The polyester composition of the present invention is a polyester composition comprising a polyester chip whose main repeating unit is ethylene terephthalate, and 0.1 to 5000 ppm of fine polyester having the same composition as the polyester chip. Therefore, the crystallization temperature (T) at the time of temperature increase of the fine measured by DSC (Differential Scanning Calorimeter)
c1 ′) is in the range of 170 to 195 ° C., which is a polyester composition.

In the polyester production process, the size set originally during granulation is used in the step of forming the melt-polymerized polymer into chips, the solid-phase polymerization step, the step of transporting the melt-polymerized polymer chips and the solid-state polymerized polymer chips, etc. Granules, powder, etc., which are considerably smaller than those of chips, are generated. Here, such fine particles and powder are referred to as fine, and a thin film having a thickness of about 0.5 mm or less is referred to as a film. In the process of producing polyester, in addition to using high-purity raw materials and auxiliary materials, filtration of molten polycondensation polymer, filtration of cooling water for polyester chips and ion exchange treatment, water introduced from outside the system for water treatment of chips Measures such as filtration, ion exchange treatment, filtration of gas used for chip transportation, etc. will be taken to prevent foreign matter and contaminants other than the polyester used from mixing in.Therefore, the fine and film-like substances will not contain foreign matter other than polyester. It is possible to exclude impurities.

Such a fine or film-like material has a property of promoting crystallization, and when it is present in a large amount, a molded article molded from such a polyester composition, particularly a bottle, is very transparent. Or the amount of shrinkage during crystallization of the bottle mouth plug does not fall within the specified range and the cap cannot be sealed. In particular, it has been found that the characteristics of the fine particles contained in the polyester composition at the time of temperature rise (Tc1 ′) have an influence on the crystallization rate of the obtained molded product and its fluctuation.

The content of the fines in the polyester composition of the present invention is 0.1 to 5000 ppm, preferably 0.1 to 3000 ppm or less, and more preferably 0.
1-1000 ppm or less, more preferably 0.1-5
00 ppm or less, most preferably 0.1 to 100 ppm
It is the following. If the blending amount is less than 0.1 ppm, the crystallization rate will be very slow and the mouthpiece of the hollow molding container will be insufficiently crystallized. Therefore, the amount of shrinkage of the mouthpiece will fall within the specified range. It does not fit, it becomes impossible to cap,
Further, the stretch-heat-fixing mold for molding the heat-resistant hollow molded container is heavily contaminated, and the mold must be frequently cleaned to obtain a transparent hollow molded container.

On the other hand, when it exceeds 5000 ppm, the crystallization rate becomes fast and the fluctuation of the rate becomes large. Therefore, in the case of a sheet-like material, the transparency and surface condition are poor, and when it is stretched, unevenness in thickness is poor. In addition, the degree of crystallinity of the plug part of the hollow molded article becomes excessive and fluctuates too much, so that the shrinkage amount of the plug part does not fall within the specified value range and capping of the plug part fails and leakage of contents occurs. In addition, the preform for hollow molding is whitened, which makes normal stretching impossible. In particular, the fine content of the polyester composition for hollow molding is 0.
1 to 500 ppm is preferable.

The fine composition of the polyester composition of the present invention has a crystallization temperature (Tc1 ') at a temperature rise of 170 to 195 ° C. measured by DSC (differential scanning calorimeter).
It is necessary to be in the range of, preferably in the range of 172 to 193 ° C, and more preferably in the range of 175 to 190 ° C.

Crystallization temperature (Tc
In the case of containing fines of 1 '), the crystallization rate of the obtained molded body such as a hollow molded body is high, so that the crystallization rate becomes high at the time of heating the plugged portion of the hollow molded body. Excessively crystallizes. As a result, the amount of contraction of the plug portion does not fall within the specified value range, resulting in defective capping of the plug portion and leakage of contents. In addition, the hollow-molding preform is whitened, which makes normal stretching impossible, resulting in uneven thickness, and the high crystallization rate results in poor transparency of the obtained hollow-molded product and also in transparency. Fluctuations will be large.
Further, the obtained sheet-like material is poor in transparency and has a high crystallization rate, so that normal stretching is impossible and the thickness unevenness is large.
Only a stretched film with poor transparency can be obtained.

Further, in order to include fine particles having a crystallization temperature (Tc1 ') at a temperature rise of more than 195 ° C., it becomes impossible unless the polyester has ethylene terephthalate units of less than 85 mol%. Polyester cannot be used for the intended purpose.

The content of the film-like material having the same composition as the polyester in the polyester composition of the present invention is 10 ppm or less, preferably 5 ppm or less, more preferably 1 ppm or less. The film-like substance has a higher crystallization-promoting effect than fine film, probably because it is oriented and crystallized, and therefore the lower limit of the compounding amount that does not have a bad influence is lowered. If the blending amount exceeds 10 ppm, the crystallization rate becomes very high, and the crystallization of the mouth plug portion of the hollow molding container becomes excessive, so that the shrinkage amount of the mouth plug portion does not fall within the specified value range, The capping of the spout becomes defective, the content leaks, and the preform for hollow molding is whitened, which makes normal stretching impossible.

In the present invention, the fact that the polyester fine or film-like material has the same composition as the polyester chip means that the fine or film-like copolymerization component and the content of the copolymerization component are the same as those of the polyester chip. Means that.

The polyester composition of the present invention can be produced, for example, as follows. That is, after the melt polycondensation, the molten polyester is extruded into water from a die and cut in water, and by the granulation method in which impact force and shear force are not applied to the chip cutting surface as much as possible, the following (1)
To chips while cooling with cooling water that satisfies at least one of (4) to (4), and then draining the chip-formed polyester chips, followed by a vibrating sieving process, a vibrating sieving process, and an airflow classification process using an air flow. Chips, fines, and film-like substances of a shape other than the prescribed size are removed and sent to a storage tank by a plug transportation system or a bucket conveyor system. Chips are taken out from the tank by a screw type feeder and transported to the next step by a plug transportation method or a bucket type conveyor transportation method, and an air flow classification step by an air flow is provided immediately before the next step. It is preferable to perform a fine removal process. N ≤ 1.0 (ppm) (1) M ≤ 0.5 (ppm) (2) S ≤ 2.0 (ppm) (3) C ≤ 1.0 (ppm) (4)

Here, the sodium content (N) in the cooling water is preferably N ≦ 0.5 ppm, more preferably N ≦ 0.1 ppm.

The magnesium content (M) in the cooling water is
M ≦ 0.3 ppm is preferable, and M ≦ 0.1 ppm is more preferable. The content (S) of silicon in the cooling water is preferably S ≦ 0.5 ppm, more preferably S ≦ 0.3 ppm. Further, the calcium content (C) in the cooling water is preferably C ≦ 0.5.
ppm, and more preferably C ≦ 0.1 ppm.

The lower limits of the sodium content (N), the magnesium content (M), the silicon content (S) and the calcium content (C) in the cooling water are N ≧
0.001ppm, M ≧ 0.001ppm, S ≧ 0.0
2 ppm and C ≧ 0.001 ppm. In order to make it below such a lower limit value, enormous capital investment is required, and the operating cost becomes very high, so that economical production is difficult.

When chips are made by using cooling water that deviates from the above conditions by a cutting method other than the underwater cutting method in which a shearing force is hard to be applied to the cut surface, these metal-containing compounds adhere to the polyester chip surface, Crystallization temperature (Tc
1 ′) is less than 170 ° C., and therefore the crystallization rate is very fast, and its fluctuation is large, which is not preferable.

When the solidified polycondensation of the melted polycondensed polyester chipped while cooling with cooling water that deviates from the above conditions, it was attached to the chip surface in the chipping step and brought into the solid phase polymerization reactor. The above-mentioned metal-containing substance adheres to the wall of the solid-state polymerization device together with a part of the surface layer of the polyester chip, and this becomes a scale with a high metal content by long-time heating at a high temperature of about 170 ° C or higher. It adheres to the vessel wall. Then, this is sometimes peeled off and mixed in the polyester chip, and becomes a foreign substance in a molded article such as a bottle, which lowers the commercial value.

Further, when a sheet is produced, the above-mentioned scale is clogged with the molten polymer filtration filter at the time of film formation, so that the filtration pressure of the filter increases sharply, resulting in poor operability and productivity. There is also the problem of becoming.

A method for suppressing the sodium content, magnesium content, silicon content, and calcium content of the cooling water of the chips to the above ranges will be illustrated below, but the present invention is not limited thereto.

In order to reduce sodium, magnesium, calcium, and silicon in the cooling water, a device for removing sodium, magnesium, calcium, and silicon is installed at at least one place in the process until industrial water is sent to the chip forming process. To do. A filter is installed to remove clay minerals such as particulate silicon dioxide and aluminosilicate. Examples of the device for removing sodium, magnesium, calcium, and silicon include an ion exchange device, an ultrafiltration device, and a reverse osmosis membrane device.

In addition, 50,000 particles having a particle size of 1 to 25 μm existing in the introduced water introduced from outside the system / 10 m
It is preferable to use water adjusted to 1 or less. The number of particles having a particle size of 1 to 25 μm in the introduced water is preferably 1,000.
0 pieces / 10 ml or less, more preferably 1000 pieces / 1
It is 0 ml or less, particularly preferably 100 pieces / 10 ml or less.

If necessary, in the case of subsequent solid-phase polymerization, the melt-polycondensed polyester which has been chipped as described above and which has been subjected to a treatment for removing fines and film-like substances is again immediately before the solid-phase polymerization step. Then, fine particles and film-like substances are removed by an air flow classification process using an air flow, and the mixture is fed to the solid phase polymerization process. When the melt-polycondensed prepolymer chips are transported to a solid-state polymerization facility or when the polyester chips after the solid-state polymerization are subjected to a sieving step, a contact treatment step with water or steam described below, or a transportation tank, these are Most of the transportation of the chips is carried out by the plug transportation system or the bucket type conveyor transportation system, and the chips are removed from the crystallization device or the solid-state polymerization reactor by using a screw feeder. It is preferable to use an apparatus that can minimize the impact on the process equipment and the transportation piping.
Immediately before filling the container as a product, fines are removed by a vibrating sieving process and an airflow classification process using an air flow.

When the melt polycondensed polyester or solid-phase polymerized polyester is subjected to contact treatment with water or steam as described below, a fine or film-like material is provided immediately before the treatment by providing an air stream classification step with an air flow. After removal, the plug transport system and bucket conveyor are used for transporting to the next process.
It is preferable to adopt the transportation method. Then, in the same manner as described above, just before filling the container as a product, fine particles and the like are removed by a vibrating sieving process and an air flow classification process using an air flow.

In the present invention, as a method for adjusting the content of the polyester fine or film-like substance within the above range, for example, the crystallization temperature at elevated temperature (Tc1 ') is 170 to 195 without passing through the sieving step. Fine and film-like having a crystallization temperature (Tc1 ′) during heating of 170 to 195 ° C. through a polyester chip having a high content of fine and film-like substances at ℃, a sieving process, and a removing process such as fines by an air flow. In addition to the method of mixing polyester chips with a very small content of the product at an appropriate ratio, it can be adjusted by changing the opening of the sieve in the removal process such as fine, and by changing the sieving speed. Any method such as can be used.

Further, in order to obtain a polyester composition which is excellent in transparency, has little variation in transparency, and gives a molded article excellent in crystallization control during molding, chips constituting the polyester composition are obtained. The crystallization temperature (Tc1) at the time of temperature rise and the crystallization temperature (Tc) at the time of temperature reduction of the molded product obtained by molding
The value of c2) is also important, and it is desirable that the temperature rise crystallization temperature (Tc1) of the molded body from chips alone is 150 ° C. or higher, and the temperature fall crystallization temperature (Tc2) is 190 ° C. or lower. The temperature rise crystallization temperature (Tc1) and the temperature decrease crystallization temperature (Tc2) of the molded body are determined as follows. 2 mm of a stepped plate obtained by the method of Example (12) below by selecting only chips from the polyester composition
Using a device described in the measuring method (8) below, a 10 mg sample from the center of the plate having a thickness was used, and the temperature was changed from room temperature to 290 ° C.
Up to 20 ° C./min, the peak temperature of the crystallization peak observed during the heating is determined, and this is used as the crystallization temperature (Tc1) during heating, and the temperature is further raised to 290 ° C. and then 290 ° C. Hold for 3 minutes, then 1 up to 240 ° C
The temperature is lowered at a rate of 0 ° C./minute, and further to room temperature at a rate of 7 ° C./minute to obtain the crystallization peak temperature observed during the temperature reduction. And

Further, the polyester composition of the present invention
It is necessary that the amount of increase of the cyclic trimer when melted at a temperature of 0 ° C. for 60 minutes is 0.50% by weight or less. Ring 3
The increase amount of the monomer is preferably 0.40% by weight or less, more preferably 0.30% by weight or less, and further preferably 0.2.
It is preferably 0% by weight or less. If the amount of increase of the cyclic trimer when melted at a temperature of 290 ° C. for 60 minutes exceeds 0.50% by weight, the amount of the cyclic trimer increases at the time of melting the resin for molding, and the oligomer on the surface of the heating mold is increased. Adhesion sharply increases, and the transparency of the obtained hollow molded article or the like is extremely deteriorated.

The polyester composition of the present invention in which the amount of the cyclic trimer increased by 0.50% by weight or less when melted at a temperature of 290 ° C. for 60 minutes was obtained after melt polycondensation or solid phase polymerization. It can be produced by deactivating the polyester polycondensation catalyst. Examples of the method for deactivating the polyester polycondensation catalyst include a method in which the polyester chips are subjected to contact treatment with water, steam, or a steam-containing gas after melt polycondensation or after solid-phase polymerization.

A method of contacting the polyester chips with water, steam or a gas containing steam to achieve the above object will be described below.

Examples of the hot water treatment method include a method of immersing in hot water and a method of pouring water on the chips with a shower. The treatment time is 5 minutes to 2 days, preferably 10 minutes to 1 day, more preferably 30 minutes to 10 hours, and the temperature of water is 20 to 180 ° C., preferably 40 to 150.
C., more preferably 50 to 120.degree.

The method of industrially performing water treatment will be illustrated below, 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.

When the polyester chips are subjected to water treatment in a batch system, a silo type treatment tank can be used. That is, the polyester chips are received in silos in a batch system and treated with water. When the polyester chips are treated with water continuously, the polyester chips can be continuously or intermittently received from the upper portion of the tower-type treatment tank for water treatment.

Whether the water treatment method is continuous or batchwise, the number of particles having a particle diameter of 1 to 25 μm existing in the water introduced from outside the system is X,
The content of sodium is N, the content of magnesium is M,
When the content C of calcium is S and the content of silicon is S, at least one of the following (5) to (9) is satisfied and water treatment is performed. 1 ≤ X ≤ 50,000 (pieces / 10 ml) (5) 0.001 ≤ N ≤ 1.0 (ppm) (6) 0.001 ≤ M ≤ 0.5 (ppm) (7) 0.001 ≤ C ≤ 1 0.0 (ppm) (8) 0.01 ≤ S ≤ 2.0 (ppm) (9)

By setting any of the number of particles in water introduced into the water treatment tank and the content of sodium, magnesium, calcium, or silicon within the above range, a metal-containing substance such as oxide or hydroxide called scale. May float in the treated water, settle, or adhere to the walls of the processing tank or piping, which may adhere to the polyester chips and permeate to promote crystallization during molding, resulting in a poorly transparent bottle. Can be prevented.

The number of particles in water introduced into the water treatment tank is 500
At least one of the steps up to the supply of natural water such as industrial water to the treatment tank is carried out as a method of reducing the number to 100 pieces / 10 ml or less.
Install devices to remove particles at more than one place.

In order to reduce sodium, magnesium, calcium and silicon in the water introduced into the water treatment tank, at least one or more of sodium and magnesium are supplied in the process until natural water such as industrial water is supplied to the treatment tank.
Install a device to remove calcium and silicon. Examples of these devices include the same devices as those used for the treatment of chip cooling water.

When the polyester chips and steam or steam-containing gas are brought into contact with each other for treatment, 50 to 50
Steam or steam-containing gas or steam-containing air at a temperature of 150 ° C., preferably 50 to 110 ° C. is preferably supplied or present as steam in an amount of 0.5 g or more per 1 kg of granular polyethylene terephthalate. The granular polyethylene terephthalate is contacted with steam.

The contact between the polyester chips and steam is usually 10 minutes to 2 days, preferably 20 minutes to
It will be held for 10 hours.

The method for industrially carrying out the contact treatment between the granular polyethylene terephthalate and steam or a steam-containing gas is illustrated below, but the method is not limited to this. Further, the treatment method may be either a continuous method or a batch method. When the polyester chips are subjected to a contact treatment with steam in a batch system, a silo type treatment device can be used. That is, the polyester chips are received in a silo, and steam or a steam-containing gas is supplied in a batch method to perform contact treatment.

When the polyester chips are continuously contacted with steam, granular tower terephthalate is continuously received from the upper part in a tower-type processing apparatus, and steam is continuously supplied in cocurrent or countercurrent to contact steam. Can be processed.

As described above, when treated with water or steam, the granular polyethylene terephthalate is drained by a draining device such as a vibrating screener or a simon carter if necessary, and the conveyor is used for the next drying step. Transfer.

For drying the polyester chips which have been subjected to the contact treatment with water or steam, a commonly used polyester drying treatment can be used. As a method for continuously drying, a hopper-type aeration dryer in which polyester chips are supplied from the upper part and a drying gas is aerated from the lower part is usually used.

As a dryer for batch-type drying, drying may be carried out under atmospheric pressure while aeration of a drying gas.

Although atmospheric air may be used as the dry gas, dry nitrogen and dehumidified air are preferable from the viewpoint of preventing a decrease in molecular weight due to hydrolysis or thermal oxidative decomposition of the polyester.

As another means for deactivating the polycondensation catalyst, there may be mentioned a method of deactivating the polymerization catalyst by adding and mixing a phosphorus compound to the melt of the polyester after solid phase polymerization.

The solid compound polyester may be blended with the phosphorus compound by dry blending the solid compound polyester with the phosphorus compound, or by melt kneading and blending the phosphorus compound with the polyester master-batch chip and the solid polymer polyester chip. A method in which a predetermined amount of a phosphorus compound is blended with polyester by a method of mixing and then melted in an extruder or a molding machine to inactivate the polycondensation catalyst, and the like.

The phosphorus compound used is phosphoric acid,
Examples include phosphorous acid, phosphonic acid and their derivatives. Specific examples thereof include phosphoric acid, phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tributyl ester, phosphoric acid triphenyl ester, phosphoric acid monomethyl ester, phosphoric acid dimethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, and phosphorous acid. Phosphoric acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, methylphosphonic acid,
Methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, phenylphosphonic acid diphenyl ester, and the like, which may be used alone or in combination of two or more. You may use together.

The cyclic 3 of the polyester composition of the present invention
The content of the monomer is preferably 0.50% by weight or less, more preferably 0.45% by weight or less, still more preferably 0.
It is 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 carried out in a heating mold, but the content of the cyclic trimer is 0.50% by weight.
When it is contained in the above amount, the adhesion of the oligomer to the surface of the heating die rapidly increases, and the transparency of the obtained hollow molded article or the like is extremely deteriorated.

The polyester composition of the present invention is obtained by adding at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin and a polyacetal resin to the above polyester composition in an amount of 0.1 ppb to 50,000 ppm.
Is a polyester composition. The blending ratio of the polyolefin resin and the like in the polyester composition of the present invention is 0.1 ppb to 50,000.
ppm, preferably 0.3 ppb-10,000 ppm,
More preferably 0.5 ppb to 100 ppm, still more preferably 1.0 ppb to 1 ppm, and particularly preferably 1.
It is 0 ppb to 45 ppb. If the compounding amount is less than 0.1 ppb, the crystallization speed will be very slow and the mouthpiece of the hollow molded article will not be sufficiently crystallized. Therefore, if the cycle time is shortened, the amount of shrinkage of the mouthpiece will be regulated. Capping failure occurs because it does not fall within the value range, and the stretching heat-fixing mold for molding the heat-resistant hollow molded body is heavily soiled,
To obtain a transparent hollow molding, the mold must be frequently cleaned. If it exceeds 50,000 ppm, the crystallization rate will be high and the crystallization of the plug part of the hollow molded article will be excessive, and the amount of shrinkage and shrinkage of the plug part will not fall within the specified range, resulting in poor capping. Leakage of the product occurs and the preform for the hollow molded body is whitened, which makes normal stretching impossible. Also, see
In the case of a sheet-like material, if it exceeds 50,000 ppm, the transparency becomes extremely poor, and the stretchability becomes poor so that normal stretching is impossible, and only a stretched film having large thickness unevenness and poor transparency can be obtained. Further, when the above-mentioned polyolefin resin or the like is used alone, it is hardly effective in preventing stains on the heating die, but it has been found that coexistence with a specific amount of fine is very effective on stains on the die.

Examples of the polyolefin resin blended in the polyester composition of the present invention include polyethylene resins, polypropylene resins, and α-olefin resins. Further, these resins may be crystalline or amorphous.

Examples of the polyethylene resin blended in the polyester composition of the present invention include ethylene homopolymer, ethylene and propylene, butene-1,3-methylbutene-1, pentene-1,4-methylpentene. −
1, hexene-1, octene-1, decene-1, and other α-olefins having about 2 to 20 carbon atoms, vinyl acetate,
Examples thereof include copolymers with vinyl compounds such as vinyl chloride, acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters, and styrene. Specifically, for example, low / medium / high density polyethylene etc. (branched or linear) ethylene homopolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-4-
Methylpentene-1 copolymer, ethylene-hexene-1
Ethylene resins such as copolymers, ethylene-octene-1 copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-ethyl acrylate copolymers Is mentioned.

Examples of the polypropylene resin blended in the polyester composition of the present invention include homopolymers of propylene, propylene, ethylene and butene.
1,3-methylbutene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, decene-
Other α-olefins having about 2 to 20 carbon atoms such as 1 and copolymers with vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester and styrene. To be Specific examples thereof include propylene-based resins such as propylene homopolymer, propylene-ethylene copolymer, and propylene-ethylene-butene-1 copolymer.

The α-olefin resin blended in the polyester composition of the present invention includes homopolymers of α-olefins having about 2 to 8 carbon atoms such as 4-methylpentene-1, and α-olefins thereof. And ethylene, propylene, butene-1, 3-methylbutene-1, pentene-
Examples thereof include copolymers with other α-olefins having about 2 to 20 carbon atoms such as 1, hexene-1, octene-1, and decene-1. Specifically, for example, butene-1 homopolymer, 4-methylpentene-1 homopolymer, butene-1-
Butene-1 type resins such as ethylene copolymer and butene-1-propylene copolymer, and 4-methylpentene-1 and C _2-
Examples thereof include copolymers with C ₁₈ α-olefins.

Examples of the polyamide resin to be blended with the polyester composition of the present invention include butyrolactam, δ-valerolactam, ε-caprolactam, enantolactam, ω-laurolactam, and other polymers of lactam, and 6-aminocapron. Acid, polymers of aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine,
Undecamethylenediamine, 2,2,4- or 2,4
Aliphatic diamines such as 4-trimethylhexamethylenediamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane)
Alicyclic diamines such as, diamine units such as aromatic diamines such as m- or p-xylylenediamine, and glutaric acid,
Aliphatic dicarboxylic acids such as adipic acid, suberic acid and sebacic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, polycondensates with dicarboxylic acid units such as aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and these And the like. Specific examples thereof include nylon 4, nylon 6, nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 69, nylon 610, nylon 611, nylon. 612, nylon 6T, nylon 6I, nylon MXD
6, nylon 6 / MXD6, nylon MXD6 / MXD
I, nylon 6/66, nylon 6/610, nylon 6/12, nylon 6 / 6T, nylon 6I / 6T and the like. Further, these resins may be crystalline or amorphous.

Examples of the polyacetal resin blended in the polyester composition of the present invention include polyacetal homopolymers and copolymers. Polyacetator
As the homopolymer, the density measured by the method of ASTM-D792 is 1.40 to 1.42 g / cm ³ , A
According to the measuring method of STMD-1238, 190 ℃, load 2
Melt flow ratio (MFR) measured at 160 g is 0.5
Polyacetal in the range of up to 50 g / 10 min is preferred.

Further, as the polyacetal copolymer,
The density measured by the method of ASTM-D792 is 1.
38 to 1.43 g / cm ³ , a polyacetal copolymer having a melt flow ratio (MFR) measured at 190 ° C. and a load of 2160 g by the measuring method of ASTM D-1238 of 0.4 to 50 g / 10 min was obtained. preferable. Examples of these copolymerization components include ethylene oxide and cyclic ethers.

In the production of the polyester composition containing the above-mentioned polyolefin resin or the like in the present invention, a resin such as the above-mentioned polyolefin resin or the like is directly added to the polyester so that the content thereof is in the above range, and the mixture is melt-kneaded. Or, by a conventional method such as a method of adding as a master-batch and melt-kneading, or the like, the resin is used in the production step of the polyester, for example, during melt polycondensation, immediately after melt polycondensation, immediately after pre-crystallization, and solid phase. At the time of polymerization, immediately after solid phase polymerization, etc., or in the process from the end of the production stage to the molding stage, etc., it is added directly as powder or granules, or the polyester chips are flowed. It is also possible to use a method of mixing the resin member under the conditions, for example, a method of mixing the resin member, or a method of melting and kneading after the contact treatment.

Here, as a method of bringing the polyester chip into contact with the resin member under flow conditions, it is preferable to bring the polyester chip into collision contact with the member in the space where the resin member exists. Specifically, for example, immediately after melt polycondensation of polyester, immediately after pre-crystallization, immediately after solid-phase polymerization, during the manufacturing process, and when filling / discharging a transport container at the transportation stage as a product of polyester chips, In addition, at the time of loading the molding machine at the molding stage of the polyester chip, pneumatic transportation pipe, gravity transportation pipe, etc.
A part of the silo, the magnet part of the magnet catcher, etc. is made of the resin, the resin film, the sheet, the molded body or the like is attached, or the resin is lined, or in the transfer path. A method of transferring the polyester chips by, for example, installing the resin member having a rod-like shape or a net-like shape may be used. The contact time of the polyester chip with the member is usually an extremely short time of about 0.01 seconds to several minutes, but a small amount of the resin can be mixed into the polyester.

Further, as the gas which comes into contact with the polyester after the melt polycondensation step or the solid phase polymerization step, the particle size is 0.3.
~ 5μm particles 1,000,000 (pieces / cubic feet)
The following, preferably 500000 (pieces / cubic feet)
Below, more preferably 100,000 (pieces / cubic sheet)
G) It is desirable to use the following gases introduced from outside the system. The particles having a particle size of more than 5 μm in the gas are not particularly limited, but preferably 5 (pieces / cubic sheet).
G)) or less, more preferably 1 (pieces / cubic foot) or less.

In the polyester production process, a container such as a silo, a molding machine hopper, a transportation container, etc. is passed through each process such as a melt polycondensation process, a solid phase polymerization process, etc., such as a sieving process and an air flow classification process. In order to transport and dry the polyester during these steps, air around the treatment equipment is generally taken into the steps by a blower or the like and used. Conventionally, such air is either left untreated or used according to JIS B 9908 (199).
It was generally used only after being treated by a cleaner equipped with a low-performance filter unit such as type 3 defined in 1). However, the polyester treated in such a process may cause a problem that only a molded product having poor transparency can be obtained. In particular, before and after the contact treatment step with the member made of the resin, when the air having the quality as described above is used as the gas that comes into contact with the polyester, the crystallization rate and the transparency of the obtained molded product largely vary. There is a high possibility that it will become a problem.

Therefore, in the method for producing a polyester composition of the present invention, at least one of the polyesters after melt polycondensation, after solid phase polymerization, after water treatment or after contact treatment with a member made of the above resin is used. However, as a gas to be contacted in any one of the transporting step to the next step, the sieving step, the storing step, and the container filling step, 1,000,000 particles having a particle size of 0.3 to 5 μm (pieces / piece)
It is desirable to use a gas introduced from outside the system below the cubic foot).

Particles having a particle diameter of less than 0.3 μm in a gas are not particularly specified, but in order to obtain a resin which gives a transparent molded product, it is preferable that the amount is small.
The number of particles having a particle size of less than 0.3 μm is preferably 100.
It is 00000 (pieces / cubic feet) or less, more preferably 5,000,000 (pieces / cubic feet) or less, and further preferably 2000000 (pieces / cubic feet or less).

A method for controlling the number of particles having a particle diameter of 0.3 to 5 μm in the gas introduced from the outside of the system to 1,000,000 (particles / cubic foot) or less is shown below, but the present invention is not limited to this. Not something to do.

Particle size in gas introduced from outside the system 0.3 to 5
As a method for reducing the number of particles of μm to 1,000,000 (pieces / cubic feet) or less, a cleaning method for removing the particles at least at one or more places during the process until the gas introduced from the outside comes into contact with the polyester chips Install the device. When the gas is air in the vicinity of the treatment facility, JIS B 9908 is used during the process in which the air introduced by the blower from the air inlet comes into contact with the polyester chips.
A gas purifier equipped with a type 1 or / and type 2 filter unit defined in (1991) is installed, and the number of particles having a particle size of 0.3 to 5 μm in the air is set to 1,000,000.
(Individual / cubic foot) It is preferable to make it below. Also,
According to JIS B 9908 (199)
It is possible to extend the life of the filter unit by installing the gas cleaning device equipped with the type 3 filter unit defined in 1) and using it together with the gas cleaning device equipped with the filter unit. .

JIS B 99 for removing particles in a gas
As a material of the ultra-high performance filter (hereinafter referred to as HEPA filter) unit of type 1 defined in 08 (1991), a filter paper made of glass fiber can be mentioned.

Also, JIS B 9908 (1991)
Examples of the material for the high-performance filter unit of the type 2 defined in 1. include a filter made of polypropylene fiber, a filter made of a laminate of Teflon (R) film and PET fiber cloth, and the like.

Generally, an electrostatic filter made of polypropylene fiber is used. In addition, JIS B 9908 (1
Examples of the material of the low-performance filter unit of the type 3 defined in 991) include non-woven fabric made of PET or polypropylene.

The intrinsic viscosity of the polyester composition of the present invention is preferably 0.55 to 1.50 deciliters / gram, and more preferably 0.58 to 1.20 deciliters / gram. When the intrinsic viscosity of the polyester is less than 0.55 deciliter / gram, the transparency, heat resistance, mechanical properties, etc. of the molded product obtained by melt molding the polyester composition of the present invention may not be sufficiently satisfied. When the intrinsic viscosity exceeds 1.50 deciliters / gram, the resin temperature rises during melting by a molding machine or the like, and thermal decomposition becomes severe, and free low-molecular weight compounds that affect aroma retention increase. However, there arises a problem that the molded body is colored yellow.

The acetaldehyde content of the polyester composition of the present invention is 50 ppm or less, preferably 3 ppm.
It is 0 ppm or less, more preferably 10 ppm or less, and further preferably 5 ppm or less. When the acetaldehyde content is 50 ppm or more, the flavor and odor of the contents such as containers molded from this polyester are deteriorated.

The amount of diethylene glycol copolymerized in the polyester according to the present invention is preferably 0.5 to 5.0 mol%, more preferably 1.0 to 5.0 mol% of the glycol component constituting the polyester. It is 4.5 mol%, and more preferably 1.5 to 4.0 mol%. When the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability is deteriorated, the molecular weight is greatly reduced during molding, and the acetaldehyde content and the formaldehyde content are increased, which is not preferable. If the content of diethylene glycol is less than 0.5 mol%, the transparency of the obtained molded product will be poor.

Further, the cyclic 3 of the polyester composition of the present invention
The content of the monomer is preferably 0.7% by weight or less, more preferably 0.50% by weight or less, and further preferably 0.4
It is 0% 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 carried out in a heating mold, but when the content of the cyclic trimer exceeds 0.7% by weight, the heating metal mold is used. Adhesion of the oligomer to the mold surface sharply increases, and the transparency of the obtained hollow molded article is extremely deteriorated.

In the present invention, the shape of the polyester chip may be any of cylinder type, square type, spherical type or flat plate type. The average particle size is usually 1.5-5 mm,
Preferably 1.6 to 4.5 mm, more preferably 1.
It is in the range of 8 to 4.0 mm. For example, in the case of a cylinder type, it is practical that the length is 1.5 to 4 mm and the diameter is about 1.5 to 4 mm. In the case of spherical particles, it is practical that the maximum particle size is 1.1 to 2.0 times the average particle size and the minimum particle size is 0.7 times or more the average particle size. Further, it is practical that the weight of the chip is in the range of 10 to 30 mg / piece.

The polyester composition of the present invention is obtained by injection molding the molded product having a thickness of 5 mm and having a haze of 15% or less, and a molded product having a thickness of 2 mm obtained by injection molding. Crystallization temperature when the test piece is heated (hereinafter "Tc1"
Is referred to as “)” in the range of 150 to 170 ° C. The haze of the molded plate is preferably 10% or less, more preferably 8% or less, and the crystallization temperature (Tc1) at the time of heating is preferably 153 to 168 ° C, more preferably 155 to 165 ° C. Is. When the haze of the molded plate exceeds 15%, the transparency of the obtained hollow molded article becomes poor, which is a problem particularly in the case of a stretched hollow molded article. On the other hand, when Tc1 exceeds 168 ° C., the heating crystallization rate becomes very slow, the crystallization of the plug portion of the hollow molded body becomes insufficient, and the problem of leakage of the contents occurs. Also,
When Tc1 is lower than 150 ° C., the transparency of the hollow molded article decreases, which is a problem.

The polyester composition of the present invention is a PET obtained by using a raw material such as dimethyl terephthalate or terephthalic acid recovered by purifying a used PET bottle by a chemical recycling method as at least a part of the starting raw material.
And PET flakes and chip PET that are used PET bottles purified and collected by the mechanical recycling method
It can be used as a mixture with.

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 in the polyester composition of the present invention.

Examples of the saturated fatty acid monoamide include lauric acid amide, palmitic acid amide, stearic acid amide and behenic acid amide. Examples of unsaturated fatty acid monoamides include oleic acid amide, erucic acid amide ricino-acid amide, and the like. Examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, and hexamethylenebisbehenic acid. Examples include amides. Examples of unsaturated fatty acid bisamides include ethylenebisoleic acid amide and hexamethylenebisoleic acid amide. Preferable amide compounds are saturated fatty acid bisamide, unsaturated fatty acid bisamide and the like. The compounding amount of such an amide compound is 1
It is in the range of 0 ppb to 1 × 10 ⁵ ppm.

Further, a metal salt compound of an aliphatic monocarboxylic acid 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, melissic acid,
It is also possible to concurrently use a lithium salt, a sodium salt, a potassium salt, a magnesium salt, a calcium salt, a cobalt salt or the like of a saturated or unsaturated fatty acid such as oleic acid or linoleic acid. The compounding amount of these compounds is 10 p
It is in the range of pb to 300 ppm.

The polyester composition of the present invention can be preferably used as a hollow molded product, a packaging material for trays, biaxially stretched films and the like, a film for coating metal cans and the like. Further, the polyester composition of the present invention can be used as one component layer such as a multilayer molded product or a multilayer film.

The polyester composition of the present invention can be used to form films, sheets, containers, and other packaging materials using a commonly used melt molding method. Also,
It is possible to improve the mechanical strength by stretching the sheet-like material comprising the polyester composition of the present invention in at least a uniaxial direction. The stretched film made of the polyester composition of the present invention is a sheet-like product obtained by injection molding or extrusion molding, and can be any of uniaxial stretching, sequential biaxial stretching, and simultaneous biaxial stretching that are usually used for stretching PET. It is molded using a stretching method. It is also possible to form into a recup shape or a tray shape by pressure forming or vacuum forming.

In producing a stretched film, the stretching temperature is usually 80 to 130 ° C. The stretching may be uniaxial or biaxial, but biaxial stretching is preferable from the viewpoint of practical physical properties of the film. In the case of uniaxial stretching, the stretching ratio is usually 1.1 to 10 times, preferably 1.5 to 8 times, and in the case of biaxial stretching, it is usually 1.1 to 8 times in each of the machine direction and the transverse direction. , Preferably 1.5 to 5 times. Also, the vertical / horizontal ratio is usually 0.5.
˜2, preferably 0.7 to 1.3. The obtained stretched film can be further heat-fixed to improve heat resistance and mechanical strength. Heat fixation is usually under tension, 120 ° C
~ 240, preferably 150 ~ 230 ℃, usually several seconds ~
It is performed for several hours, preferably several tens of seconds to several minutes.

In producing a hollow molded article, a briform molded from the polyester composition of the present invention is stretch blow molded, and an apparatus conventionally used in PET blow molding can be used. Specifically, for example, a preform is once molded by injection molding or extrusion molding, and as it is or after processing the plug portion and the bottom portion, it is reheated, and biaxial stretch blow molding such as hot parison method or cold parison method. The law applies. In this case, the molding temperature, specifically, the temperature of each part of the cylinder of the molding machine and the temperature of the nozzle are usually in the range of 260 to 300 ° C. The stretching temperature is usually 70 to 120 ° C, preferably 90 to 120 ° C.
At 110 ° C, the draw ratio is usually 1.5-3.5 in the machine direction.
It may be performed in the range of 2 to 5 times in the circumferential direction. The obtained hollow molded article can be used as it is, but in particular, a fruit juice beverage,
In the case of beverages such as oolong tea that require hot filling, they are generally used after being subjected to heat setting treatment in a blow mold to impart heat resistance. The heat setting is usually 100 to 200 ° C., preferably 12 under tension such as compressed air.
It is carried out at 0 to 180 ° C. for several seconds to several hours, preferably several seconds to several minutes.

In order to impart heat resistance to the spout,
The plug part of the preform obtained by injection molding or extrusion molding is crystallized in an oven equipped with a far infrared or near infrared heater, or the plug part is molded with the above heater after bottle molding. Crystallize.

In the polyester composition of the present invention, if necessary, known ultraviolet absorbers, antioxidants, oxygen scavengers,
A lubricant added from the outside or a lubricant that is internally precipitated during the reaction,
You may mix | blend various additives, such as a mold release agent, a nucleating agent, a stabilizer, an antistatic agent, a dye, and a pigment.

When the polyester composition of the present invention is used for a film, in order to improve handling properties such as slipperiness, winding property and blocking resistance, calcium carbonate and magnesium carbonate are added to the polyester composition. Inorganic particles such as barium carbonate, calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, and magnesium phosphate, organic salt particles such as calcium and calcium oxalate, barium, zinc, manganese, and magnesium terephthalate and divinylbenzene, Inert particles such as cross-linked polymer particles such as styrene, acrylic acid, methacrylic acid, vinyl monomers of acrylic acid or methacrylic acid, homopolymers or copolymers thereof can be contained. In addition, the measuring method of the main characteristic value in this invention is demonstrated below.

[0125]

EXAMPLES The present invention will now be described in detail 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 mixed solvent of 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio).

(2) Polyethylene diethylene glycol
Content (hereinafter referred to as "DEG content") It was decomposed with methanol, the amount of DEG was quantified by gas chromatography, and the content was expressed as a ratio (mol%) to all glycol components.

(3) Content of cyclic trimer of polyester (hereinafter referred to as "CT content") 300 mg of a sample was dissolved in 3 ml of hexafluoroisopropanol / chloroform mixture (volume ratio = 2/3), Dilute by adding 30 ml of chloroform.
15 ml of methanol was added to this to precipitate the polymer, and the polymer was filtered. 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.

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

(5) Increasing amount of cyclic trimer during melting of polyester (ΔCT amount) 3 g of dried polyester chips were placed in a glass test tube and immersed in an oil bath at 290 ° C. for 60 minutes under a nitrogen atmosphere to melt. Let The amount of cyclic trimer increase during melting is determined by the following formula. Increase of cyclic trimer at melting (wt%) = cyclic 3 after melting
Content of monomer (% by weight) -Content of cyclic trimer before melting (% by weight)

(6) Measurement of fine content and film-like material content About 0.5 kg of resin was used as a sieve (A) with a wire mesh having a nominal size of 5.6 mm according to JIS-Z8801 and a nominal size of 1.7.
A sieve (diameter 20 cm) (B) having a wire mesh of mm was placed on a sieve in which two stages were combined, and sieved with a swinging type sieving tow machine SNF-7 manufactured by Terraoka at 1800 rpm for 1 minute. This operation was repeated, and a total of 20 kg of the resin was sieved. Apart from the film-like material having a thickness of about 0.5 mm or less, two or more chips are fused to each other on the sieve (A), or a chip-like material cut into a size larger than the normal shape. When the fine particles that have been captured are removed, the remaining film-like material having a thickness of about 0.5 mm or less and the fines that have been sieved off under the sieve (B) are washed separately with ion-exchanged water and then washed with Iwaki. It was collected by filtering with a G1 glass filter manufactured by Glass Co. Put these together with the glass filter in a dryer at 100 ° C.
After drying for 2 hours, it was cooled and weighed. The same operation of washing with ion-exchanged water and drying was repeated again to confirm that the weight became constant, and the weight of the glass filter was subtracted from this weight to determine the fine weight and the weight of the film-like material.
Fine content or film content is fine weight or film weight / total screened resin weight. The total content is calculated from these values.

(7) Crystallization temperature (Tc
1 ') Measurement Differential scanning calorimeter (DS) manufactured by Seiko Denshi Kogyo KK
C), measured using RDC-220. In (6),
Fines collected from 20 kg of polyester were dried under reduced pressure at 25 ° C. for 3 days, and a sample 10 was used for each measurement.
mg was used. Temperature rising rate from room temperature to 290 ℃ 20 ℃
The temperature is raised at a rate of / min, the temperature is held at 290 ° C. for 3 minutes, and then rapidly cooled with liquid nitrogen. Next, the crystallization peak temperature observed when the temperature is raised again under the same conditions is determined, and this is set as the crystallization temperature at elevated temperature (Tc1 '). However, when there are two crystallization peak temperatures, the crystallization peak temperature on the high temperature side is obtained and this is set as the crystallization temperature during temperature increase (Tc1 ′). The measurement was carried out on a maximum of 10 fine samples, and the average value of the crystallization temperature (Tc1 ′) at the time of heating was calculated.
This is defined as the fine temperature-increasing crystallization temperature (Tc1 ′).

(8) Crystallization temperature (Tc
1) Differential thermal analyzer (DS) manufactured by Seiko Electronics Co., Ltd.
C), measured with RDC-220. Using 10 mg of a sample from the center of a 2 mm-thick plate of the following (13) shaped plate. The temperature is raised at a temperature rising rate of 20 ° C./minute, and the peak temperature of the crystallization peak observed during the heating is measured and used as the crystallization temperature during heating (Tc1 ′).

(9) Average Density of Polyester Chip and Density of Preform Mouth Portion Measured at 30 ° C. with a density gradient tube of calcium nitrate / water mixed solution.

(10) Haze (% haze) and haze unevenness Samples were cut from the body (wall thickness 5 mm) of the following (13) and the body (wall thickness about 0.4 mm) of the hollow molded body of (14). , Nippon Denshoku Co., Ltd. haze meter, model NDH2
Measured at 000. In addition, a forming plate formed 10 times in succession
The haze (wall thickness: 5 mm) was measured, and the haze unevenness was determined by the following. Haze spot = maximum haze value / minimum haze value

(11) Density increase due to heating of preform plug part The preform plug part was heat-treated for 180 seconds by a home-made infrared heater, and a sample was taken from the top surface to measure the density.

(12) Molding of Stepped Molded Plate In the molding of the stepped molded plate according to this patent, polyester chips dried under reduced pressure at 140 ° C. for about 16 hours using a vacuum dryer are injection molded by Meiki Seisakusho. Machine M-150C
-With a DM type injection molding machine, having a gate portion (G) as shown in FIGS. 1 and 2, 2 mm to 11 mm (thickness of A portion = 2
mm, thickness of B part = 3 mm, thickness of C part = 4 mm, thickness of D part = 5 mm, thickness of E part = 10 mm, thickness of F part =
A step-formed plate having a thickness of 11 mm) was injection-molded.

A polyester chip previously dried under reduced pressure using a vacuum dryer DP61 manufactured by Yamato Kagaku Co., Ltd. was used. A dry inert gas (nitrogen gas) was purged in the molding material hopper in order to prevent moisture absorption of the chip during molding. went. M-1
The conditions for plasticization by a 50C-DM injection molding machine are: feed screw rotation speed = 70%, screw rotation speed =
120 rpm, back pressure 0.5 MPa, cylinder temperature is 45 ° C, 250 ° C in order from directly below the hopper, and thereafter 29 including nozzle.
It was set to 0 ° C. The injection conditions are injection speed and holding speed 2
The injection pressure and the holding pressure were adjusted to 0% and the weight of the molded product was 146 ± 0.2 g, and the holding pressure was adjusted to be 0.5 MPa lower than the injection pressure.

The upper limits of the injection time and the pressure holding time are each 10
Second, 7 seconds and cooling time are set to 50 seconds, and the total cycle time including the molded product take-out time is about 75 seconds. Cooling water having a water temperature of 10 ° C. is constantly introduced into the mold to adjust the temperature, but the mold surface temperature at the time of stable molding is about 22 ° C.

The test plate for evaluating the characteristics of the molded product was prepared by introducing the molding material and replacing the resin, and then 11 to 11 from the start of molding.
It was arbitrarily selected from the stable molded products of the 18th shot. The 2 mm thick plate (A part in FIG. 1) is used for crystallization temperature (Tc1) measurement at the time of temperature rise, and the 5 mm thick plate (D part in FIG. 1) is used for haze (% haze) measurement.

(13) Molding of Hollow Molded Body Polyester was dried by a dryer using dehumidified air, and a preform was molded at a resin temperature of 290 ° C. by an M-150C (DM) injection molding machine manufactured by each machine manufacturer. The mouthpiece of this preform was heated and crystallized by a homemade mouthpiece crystallization device. Next, this preform was biaxially stretch-blown at a magnification of about 2.5 times in the longitudinal direction and about 3.8 times in the circumferential direction with an LB-01E molding machine manufactured by CORPOPLAST, and subsequently about 15
Heat set in a mold set at 0 ° C for about 7 seconds, and the capacity is 20
A 00 cc container (body thickness 0.45 mm) was molded.
The stretching temperature was controlled at 100 ° C.

(14) Evaluation of Leakage of Contents from Hollow Molded Body The hollow molded body molded in the above (13) was filled with 90 ° C. hot water, capped with a capping machine, and then the container was laid down and left to stand. I investigated the leak. In addition, the state of deformation of the spout after capping was also examined.

(15) Sodium content, calcium content, magnesium content and silicon content in the cooling water of the chipping step and the introduced water of the water treatment step Collect the cooling water or the introduced water after particle removal and ion exchange. , 1G1 glass filter manufactured by Iwaki Glass Co., Ltd., and then the filtrate is subjected to an atomic absorption method, an ICP method, or an ICP-MS.
Measured by the method.

(16) Measurement of the Number of Particles in Cooling Water in the Chip Making Step, and Introduced Water and Recycled Water in the Water Treatment Step Cooling water in the chip making step, introduced water after particle removal and ion exchange, or a filtration device (5 ) And the recycled water treated in the adsorption tower (8) were measured using PAC 150 manufactured by Seishin Enterprise Co., Ltd., which is a particle measuring device by the light blocking method, and the number of particles was expressed as 10/10 ml.

(17) Measurement of the Number of Particles in Gas Contacting Polyester Chips The gas sent by a blower for forcibly sending the gas and passing through the gas cleaning device is branched from the main gas stream before contacting the chips. Then, it is introduced into a particle measuring instrument and measured. The measurement is repeated 5 times, the average value is obtained, and the number of gas per 1 cubic foot is calculated. As the particle measuring instrument, a light scattering type particle measuring instrument KC-01B manufactured by Rion Co., Ltd. was used.

Example 1 A slurry of high-purity terephthalic acid and ethyl glycol was continuously fed to a first esterification reactor containing a reactant in advance, and the slurry was stirred to about 2
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 under stirring at about 260 ° C. and 0.05 kg / cm ² to a predetermined degree of reaction. Further, crystalline germanium dioxide was heated and dissolved in water, and ethylene glycol was added thereto, and the catalyst solution and the ethylene glycol solution of phosphoric acid which were heat-treated were separately and continuously supplied to the second esterification reactor. did. This esterification reaction product is continuously fed to the first
It is supplied to the polycondensation reactor and stirred at about 265 ° C at 25 to
rr for 1 hour, then in a second polycondensation reactor under stirring for about 2
Polycondensation was performed at 65 ° C. and 3 torr for 1 hour, and further with stirring in the final polycondensation reactor at about 275 ° C. and 0.5 to 1 torr for 1 hour. The intrinsic viscosity of the melt polycondensation prepolymer is 0.
It was 55 dl / g.

The melt polycondensation reaction product was cooled with cooling water (sodium content 0.01 ppm, magnesium content 0.01
ppm, calcium content is 0.02 ppm, silicon content is 0.09 ppm) While cooling, chips are formed in an underwater cutting granulator, and chips at about 50 ° C or less are transported to a storage tank, and then vibrated screen. The fine content and the film-like material were removed by the separation step and the airflow classification step, so that the fine content was about 50 ppm or less. Then, it is sent to a crystallizer by a bucket type conveyor transportation system, continuously crystallized at about 155 ° C. for 3 hours under nitrogen gas flow, and then put into a tower type solid-phase polymerizer at about 208 ° C. under nitrogen gas flow. Solid phase polymerization was continuously carried out to obtain a solid phase polymerized polyester. After the solid phase polymerization, fines and film-like substances were removed by continuous treatment in a sieving step and a fines removing step, and stored in a storage tank.

The intrinsic viscosity of the obtained PET composition was 0.7.
4 deciliter / gram, DEG content 2.8 mol%, cyclic trimer content 0.31% by weight, cyclic trimer increase 0.43% by weight, average density 1.4028 g /
cm ³ , AA content was 3.0 ppm, and fine content was about 50 ppm. In addition, the crystallization temperature (Tc1 ′) of fines when heated was 185 ° C. The Ge residual amount measured by atomic absorption spectrometry was 44 ppm, and the P residual amount was 30 ppm.

The PET composition thus obtained was evaluated using a molded plate and a biaxially stretched molded bottle. The results are shown in Table 1.
Shown in. The haze of the molded plate is 4.0%, the haze unevenness of the molded plate is 0.2%, the Tc1 of the molded plate is 168 ° C., the density of the plug portion is 1.377 g / cm ³ , and the density deviation of the plug portion is 0.002 g.
The value was / cm ³ and there was no problem.

In the leak test of the contents, there was no problem and the mouth plug was not deformed. The body haze of the obtained bottle was as good as 0.9%. The AA content of the bottle was 21.8 ppm, which was a value with no problem. Also, 500
Although 0 or more continuous drawing blow moldings were carried out, no mold stain was observed and there was no problem.

In the manufacturing process, the melt-polymerized prepolymer chips, the solid-phase polymerized chips, and the water-treated chips are all transported by the bucket type conveyor transportation system, and all the chips are extracted from the reactor or the storage layer by the screw type feeder. −
Was used. The same method was used for the transportation and extraction methods of Examples 2 to 5.

Also, melt polycondensation PET chips and solid-state polymerization P
ET chips are filled in a transport container or a storage container, and the air that comes into contact with the chips before storage is JIS B 99.
08 (1991) Type 3 PET non-woven filter unit equipped with an air purifier and JIS B 9908
HEP with (1991) type 1 particle collection rate of 99% or more
Air filtered by an air cleaner equipped with the A filter unit (the number of particles having a particle size of 0.3 to 5 μm is about 500 / cubic foot) was used. The same applies to Examples 2 to 5 and Comparative Example 1.

Example 2 The PET chip obtained in Example 1 was treated with water as follows. Raw material chip supply port (1) in the upper part of the treatment tank, overflow discharge port (2) located at the upper limit level of the treated water in the treatment tank, and discharge port (3) of the mixture of polyester chips and treated water in the lower part of the treatment tank. ), This
The treated water discharged from the flow outlet, the treated water discharged from the treatment tank, and the treated water discharged from the discharge section at the bottom of the treatment tank through the draining device (4) have a filter medium made of paper. (6) which is sent to the water treatment tank again via the fine powder removing device (5) which is a continuous type filter of (1), an inlet (7) for these fine powder removed treated water, and acetaldehyde in the fine powder removed treated water. With an adsorption tower (8) for adsorbing water and a new ion exchange water inlet (9)
The m ³ tower type processing tank shown in FIG. 3 was used.

The solid-state polymerized PET chips of Example 1 were subjected to a treatment for removing fines and film-like substances by a vibrating sieving process and an air stream classifying process, and then placed in a water treatment tank controlled at a treated water temperature of 95 ° C. Water is continuously supplied from the supply port (1) at the upper part of the treatment tank at a rate of 50 kg / hour,
50 as a PET chip from the discharge port (3) at the bottom of the processing tank
It was continuously withdrawn at a rate of kg / hour together with the treated water.

Ion-exchanged water inlet (9) of the above processing apparatus
The content of particles having a particle size of 1 to 25 μm in the introduced water collected before is about 1900 particles / 10 ml, the sodium content is 0.01 ppm, and the magnesium content is 0.01 pp.
m, calcium content is 0.01 ppm, silicon content is 0.09 ppm, and the number of particles of the recycled water after treatment in the filtration device (5) and the adsorption tower (8) is about 12000. / 10 ml. The PET after the water treatment was subjected to a treatment for removing fines and the like in a vibrating screen step and an air stream classification step.

The PET composition thus obtained had an intrinsic viscosity of 0.7.
4 deciliter / gram, DEG content 2.8 mol%, cyclic trimer content 0.31% by weight, cyclic trimer increase 0.08% by weight, average density 1.4028 g /
cm ³ , the AA content was 3.3 ppm, the fine content was about 50 ppm, and the fine crystallization temperature (Tc1 ′) at elevated temperature was 188 ° C.

The PET composition thus obtained was evaluated in the same manner as in Example 1 using a molded plate and a biaxially stretched molded bottle. The results are shown in Table 1. The result was fine.

Example 3 The water-treated solid-state polymerized PET obtained in Example 2 was used. Linear low-density polyethylene (MI = about 0.9 g was added to the resulting water-treated PET.
/ 10 min, density = 0.923 g / cm ³ ) is kneaded by a twin-screw extruder to make a PET master (fine content is about 50 ppm) in which the polyethylene is finely dispersed, and is treated with water as described above. P obtained by mixing this master with PET so that the polyethylene content was about 10 ppb
The ET composition was evaluated using a molded plate and a biaxially stretched molded bottle. The results are shown in Table 1. PET obtained
The properties of the composition and the properties of the bottle were good and there were no problems.

Example 4 As a polycondensation catalyst, a solution of tetraisopropyl titanate in ethylene glycol and crystalline germanium dioxide were dissolved by heating in water, and ethylene glycol was added to the solution, followed by heat treatment. Melt polycondensation and solid phase polymerization were carried out in the same manner as in Example 1 except that it was used. Then, the P obtained by the same method as in Example 2 was obtained.
The ET chip was water treated. The obtained PET composition had an intrinsic viscosity of 0.74 deciliter / gram, a DEG content of 2.8 mol%, a cyclic trimer content of 0.31 wt%,
Cyclic trimer increase is 0.28% by weight, average density is 1.4
The content was 029 g / cm ³ , the AA content was 3.3 ppm, the fine content was about 50 ppm, and the fine crystallization temperature (Tc1 ′) at elevated temperature was 189 ° C. The Ge residual amount measured by atomic absorption spectrometry was 25 ppm, the Ti residual amount was 0.8 ppm, and the P residual amount was 10 ppm. In the same manner as in Example 1, a molded plate and a biaxially stretched molded bottle were evaluated. The results are shown in Table 1.

The haze of the molded plate is 4.5%, the Tc of the molded plate is
No. 1 was 168 ° C., and the density of the spout was 1.379 g / cm ^3, which was a problem-free value, and continuous stretch blow molding of 5000 or more pieces was carried out, but no mold stain was observed, and the bottle was transparent. The property was also good. In addition, in the leak test of the contents, there was no problem and the mouth plug was not deformed. The body haze of the obtained bottle was as good as 0.9%. The AA content of the bottle was 18.8 ppm, which was a value with no problem.

Example 5 As a polycondensation catalyst, crystalline germanium dioxide was dissolved in water by heating, and ethylene glycol was added to the solution, followed by heat treatment, and a solution of basic aluminum acetate in water / ethylene glycol. Example 1 except that these catalyst solutions and the ethylene glycol solution of phosphoric acid were separately and continuously fed to the second esterification reactor.
Melt polycondensation and solid phase polymerization were carried out in the same manner as in. Then, the PET chips obtained were treated with water in the same manner as in Example 2.

The PET composition obtained had an intrinsic viscosity of 0.7.
4 deciliters / gram, DEG content 2.8 mol%, cyclic trimer content 0.31% by weight, cyclic trimer increment 0.25% by weight, average density 1.4029 g /
cm ³ , AA content is 3.3 ppm, fine content is about 50 ppm, fine crystallization temperature (Tc
1 ') was 188 ° C. Ge residual amount measured by atomic absorption spectrometry is about 19 ppm, Al residual amount is 8 pp
The residual amount of m and P was 18 ppm.

Evaluation was carried out in the same manner as in Example 1 using a molded plate and a biaxially stretched molded bottle. The results are shown in Table 1.
The haze of the molded plate is 4.2%, the Tc1 of the molded plate is 167.
℃, the density of the plug part is 1.379 g / cm ^{3, which} is a problem-free value, and continuous stretch blow molding of 5000 or more pieces was carried out, but no mold stain was observed and the transparency of the bottle was good. Met. In addition, in the leak test of the contents, there was no problem and the mouth plug was not deformed. The body haze of the obtained bottle was as good as 1.0%. The AA content of the bottle was 19.2 ppm, which was a problem-free value.

Example 6 After separating and removing a bottle made of a different resin, a used polyethylene terephthalate bottle from which a label and a cap have been removed is crushed and washed with water to recover recovered flakes with ethylene glycol in the presence of a depolymerization catalyst. The crude dimethyl terephthalate obtained by polymerization and then transesterification with methanol was purified by distillation, and the purified dimethyl terephthalate thus obtained was hydrolyzed to obtain high-purity terephthalic acid.

The slurry of terephthalic acid and ethylene glycol (virgin product) (ethylene glycol / terephthalic acid molar ratio = 1.6) was charged with bis (hydroxyethyl) terephthalate and kept at a temperature of 250 ° C. and normal pressure. The esterification reaction was supplied to the esterification reaction tank, and the esterification reaction was carried out for 4 hours while distilling out water produced as a by-product, and 100 kg of this esterification reaction product was transferred to the polycondensation tank. Subsequently, in the polycondensation tank to which the esterification reaction product was transferred, the same crystalline germanium ethylene glycol solution as that used in Example 1 and ethylene glycol of phosphoric acid were fed from a plurality of polycondensation catalyst supply pipes. After the glycol solution was added, the temperature in the system was increased from 250 ° C to 2 ° C over 1 hour.
The temperature is raised to 75 ° C and the atmospheric pressure is reduced to 350P in 1 hour.
Then, it was subjected to melt polycondensation under a reduced pressure of 150 Pa at 278 ° C. for a time such that the obtained resin had an intrinsic viscosity of 0.55 dl / g. It was withdrawn in a strand form from an outlet provided at the bottom of the polycondensation tank, and was made into chips while being cooled with ion-exchanged water of the same quality as used in Example 1 to bring the chip temperature to about 50 ° C. or lower, and then a vibrating screen sifter The fine content was reduced to about 50 ppm or less by removing fines and film-like substances.

Subsequently, the polyester resin chip obtained above was crystallized by a stirring flow type crystallizer held at about 160 ° C., and then transferred to a packed column type solid phase polymerization column, and nitrogen was passed under a nitrogen flow of 210. Solid phase polymerization was carried out at 0 ° C., and then fine particles were removed by treatment in a sieving step and a fine removing step so that the fine content was about 50 ppm. The obtained PET has an IV of 0.75 deciliter / gram and a DEG content of 3.2.
Mol%, AA content was 4.3 ppm, cyclic trimer content was 0.35% by weight, no film-like material was contained, and Tc1 'of Fine was 188 ° C. The remaining Ge amount is 5
The amount of residual P was 1 ppm and 32 ppm. This P
The ET was evaluated using a molded plate and a biaxially stretched molded bottle.

The haze of the molded plate was 9.3%, the haze unevenness of the molded plate was 0.3%, and the Tc1 of the molded plate was 165 ° C. Bottle mouth density of the plug portion is 1.378g / cm ^3, the spout unit density deviation of no value problem and 0.003 g / cm ^3, the body portion haze of the bottle was good and 1.5%. In addition, in the leak test of the contents, there was no problem and the mouth plug was not deformed. The AA content of the bottle was 23.2 ppm, which was a value with no problem. In the manufacturing process, the melt-polymerized prepolymer chips, the solid-state polymerized chips, and the like were transported in the same manner as in Example 1.

Comparative Example 1 A prepolymer melt-polycondensed in the same manner as in Example 1 except that the amount of the catalyst added was increased,
Industrial water (sodium content 4.3 ppm, magnesium content 1.8 ppm, calcium content 5.9)
ppm, silicon content is 10.0 ppm) while cooling the chips into chips with a strand cut granulator to a chip temperature of about 70 ° C, without removing fines, etc. Shipped to different storage silos. Next, this was put into a rotary tumbler, and while being rotated, it was crystallized at 140 ° C. under reduced pressure and then solid-phase polymerized at 215 ° C.

The obtained PET composition was not treated with a fine removing device. The obtained PET composition,
Table 1 shows the characteristics of the molded plate and the biaxially stretched molded bottle obtained by molding this. The transparency of the obtained bottle was poor, and the deformation of the spout and leakage of the contents were examined, and leakage of the contents was found.

[0170]

[Table 1]

[0171]

According to the polyester composition of the present invention,
It has excellent crystallization controllability during melt molding and long-term continuous moldability, and the hollow molded article, sheet-like material and stretched film obtained therefrom have excellent transparency and heat-resistant dimensional stability. The shrinkage rate of the plug portion of the hollow molded body is in an appropriate range, and residual off taste and offensive odor hardly occur when the liquid container is formed.

[Brief description of drawings]

FIG. 1 is a plan view of a stepped molding plate used in Examples.

FIG. 2 is a side view of the step forming plate of FIG.

FIG. 3 is a schematic diagram of a water treatment device used in Examples.

[Explanation of symbols] 1 raw material chip supply port 2 overflow discharge port 3 discharge port for polyester chips and treated water 4 drainer 5 fines removal device 6 piping 7 recycled water or / and ion exchanged water inlet 8 Adsorption tower 9 Ion exchange water inlet

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshitaka Eto             20 No. 248 Takashiro, Shiga Town, Shiga District, Shiga Prefecture F-term (reference) 4F207 AA03 AA24 AA29 AA32 AG07                       AG08 KA01 KA17                 4F208 AA24C AA24D AA24K AG07                       LA02 LA04 LB01                 4J002 BB033 BB053 BB063 BB073                       BB083 BB123 BB143 BB153                       BB173 CB003 CF031 CF032                       CF041 CF042 CF051 CF052                       CF081 CF082 CL013 CL033                       CL053 FD010 FD030 GG01

Claims (8)

[Claims] 1. A polyester chip whose main repeating unit is ethylene terephthalate, and a polyester fine 0.1 having the same composition as the polyester chip.
Polyester composition consisting of ˜5000 ppm, wherein the fine crystallization temperature (Tc1 ′) at elevated temperature measured by DSC (differential scanning calorimeter) is in the range of 170 to 195 ° C. Composition. 2. The polyester composition according to claim 1, wherein the content of the polyester film material having the same composition as that of the polyester chips is 10 ppm or less. 3. The polyester composition according to claim 1, wherein the cyclic trimer increase amount when melted at a temperature of 290 ° C. for 60 minutes is 0.50% by weight or less. object. 4. The polyester composition according to claim 1, wherein the content of the cyclic trimer is 0.7% by weight or less. 5. The polyester composition according to claim 1, further comprising 0.1 ppb to 50000 ppm of at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin, and a polyacetal resin. A polyester composition comprising: 6. A hollow molded article obtained by molding the polyester composition according to claim 1. 7. A sheet obtained by extruding the polyester composition according to claim 1.
Grit. 8. A stretched film obtained by stretching the sheet-like material according to claim 7 in at least one direction.