JP2002173524A - Polyester, and hollow molded product, sheet-shaped product and stretched film comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow molded product having excellent transparency and heatproof size stability, especially polyester which can produce a small-sized hollow molded product effectively by high speed molding, scarcely stains a mold and has excellent long continuous moldability, and a hollow molded product, a sheet-shaped product and stretched film comprising the polyester. SOLUTION: The polyester is constituted with a main recurring unit of polyethylene terephthalate, and a molded product obtained from the polyester has a crystallization temperature (Tc) at the time of heat-up in the range of 120 deg.C to 150 deg.C. The crystallization temperature is measured with a differential scanning calorimeter(DSC) after heat treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester and a hollow molded article, a sheet and a stretched film made of the same, and more particularly, to a crystallization control property at the time of melt molding.
The present invention relates to a polyester having excellent long-term continuous moldability, and a molded product, a sheet-like material, and a stretched film having excellent transparency and heat-resistant dimensional stability.

[0002]

2. Description of the Related Art Polyesters whose main repeating unit is ethylene terephthalate (hereinafter sometimes abbreviated as PET) have excellent transparency, mechanical strength and heat resistance.
Depending on the properties such as gas barrier properties, carbonated beverages, juices,
It is used as a material for containers such as mineral water, and its use has been remarkable. In these applications, polyester bottles are hot-filled with beverages that have been sterilized at high temperatures, or beverages are sterilized at high temperatures after filling, but ordinary polyester bottles shrink during such hot-filling processes. However, deformation occurs and becomes a problem. As a method for improving the heat resistance of the polyester bottle, a method has been proposed in which the crystallinity is increased by heat-treating the bottle cap portion, or the stretched bottle is heat-fixed. In particular, if the plug portion is insufficiently crystallized or has a large variation in crystallinity, the sealing performance with the cap is deteriorated, and the contents may leak.

[0003] In the case of beverages that require hot filling, such as fruit juice beverages, Wurong tea and mineral water, the plug portion of the preform or molded bottle is heat treated to crystallize. (Methods described in JP-A-55-79237, JP-A-58-110221, etc.) are generally used. Such a method, that is, a method of improving the heat resistance by heat treatment of the plug portion and the shoulder portion, the time and temperature for the crystallization treatment greatly affect the productivity, and the crystal can be processed at a low temperature and in a short time. It is preferable that the PET is a PET having a high conversion rate. On the other hand, the body is required to be transparent even when subjected to a heat treatment at the time of molding so as not to deteriorate the color tone of the contents of the bottle, and the plug and the body need to have contradictory characteristics.

In order to improve the heat resistance of the body of the bottle, a method of performing heat treatment at a high temperature of a drawing blow mold as disclosed in Japanese Patent Publication No. 59-6216, for example, is adopted. However, when a large number of bottles are continuously formed using the same mold by such a method, the bottle obtained with a long operation is whitened, the transparency is reduced, and only a bottle having no commercial value can be obtained. . It was found that this was due to the attachment of the PET-derived material to the mold surface, resulting in mold stains, and the mold stains being transferred to the bottle surface. In particular, in recent years, the molding speed of bottles has been increased in order to reduce costs, and from the viewpoint of productivity, shortening the heating time for crystallization of the plug and contamination of the mold have become more serious problems. ing.

[0005] Further, PET is extruded into a sheet-like material, which is stretched biaxially to produce a stretched film. At this time, the PET film is added to a cooling roll or a stretching roll of the unstretched film.
Is attached, resulting in a bad influence on the production operability of the sheet-like material and the stretched film, and also the transparency of the obtained product is deteriorated.

[0006]

Various proposals have been made to solve such a problem. For example, a method of adding an inorganic nucleating agent such as kaolin or talc to polyethylene terephthalate (JP-A-56-2342, JP-A-56-21832), or an organic nucleating agent such as a montanic acid wax salt. Although there is a method of adding (JP-A-57-125246 and JP-A-57-207639), these methods have a problem in practical use due to generation of foreign matters and cloudiness. Also, a method in which a treated polyester obtained by pulverizing a polyester molded product obtained by melt-molding the polyester is added to the raw material polyester (JP-A-5-105807).
However, this method requires an extra step of melt-molding and pulverization, and furthermore, there is a risk that impurities other than polyester may be mixed in such a post-process. is not. In addition, a method of inserting a heat-resistant resin piece into a plug (Japanese Patent Laid-Open No. 61-259)
946 and JP-A-2-26938), but the productivity of bottles is poor and there is a problem in recyclability.

In order to solve such a problem of mold contamination, a method of reducing cyclic trimer, which is a main component of the deposit on the mold surface, by subjecting PET to solid phase polymerization in advance has been performed. However, this method is insufficient in its effect because the cyclic trimer regenerates when remelting and forming parison. Further, Japanese Patent Publication No. 3-47830 discloses a method in which polyester is treated with water at 90 to 110 ° C. to suppress the activity of a catalyst and to control the formation of a cyclic trimer during parison molding. However, in this method, although mold stains are temporarily reduced, they are still insufficient, and in some cases, a sufficient effect may not be obtained.Also, when the obtained molded article has insufficient transparency, there were.

The present invention solves the above-mentioned problems of the conventional method and can efficiently produce a molded article having excellent transparency and heat-resistant dimensional stability, especially a heat-resistant hollow molded article. It is an object of the present invention to provide a polyester excellent in long-term continuous moldability, which does not contaminate the polyester, and a molded article made thereof.

[0009]

In order to achieve the above-mentioned object, the polyester of the present invention is a polyester whose main repeating unit is composed of ethylene terephthalate, and is measured by a differential scanning calorimeter (DSC). It is characterized in that the measured crystallization temperature (Tc) of the molded body obtained from the polyester after heat treatment at the time of heating is in the range of 120 ° C to 150 ° C.

The polyester having the above-mentioned properties can be easily molded into a molded article having excellent transparency and heat-resistant dimensional stability, particularly a hollow molded article such as a container, by melt-molding the polyester. It is possible to obtain a polyester excellent in long-time continuous moldability that does not stain the mold more than the catalyst deactivated resin by the treatment.

Here, the crystallization temperature (Tc) of the molded article obtained from the polyester after the heat treatment, as measured by a differential scanning calorimeter (DSC), is Pe as follows.
Differential thermal analyzer (DSC) manufactured by rkin-elmer, DSC-7
90 ° C. from room temperature to 500 ° C./min using C
After the treatment at this temperature for 2.0 minutes, and the temperature of the crystallization peak of the molded article observed during the heating to 180 ° C. at a rate of 20 ° C./min.

In this case, the differential scanning calorimeter (D
The crystallization temperature (Tc1) at the time of temperature rise of the molded body, measured by SC), can be in the range of 150 ° C to 175 ° C. In this case, the haze of the molded product is 15%
It can be:

In this case, the polyester can be a mixture of the polyester chips and 0.1 to 300 ppm fine of the same composition of polyester.

In this case, at a temperature of 290 ° C., 60
0.30% by weight increase of cyclic trimer when melted for 1 minute
It can be:

In this case, a polyolefin resin,
At least one resin selected from the group consisting of a polyamide resin, a polyacetal resin, and a polybutylene terephthalate resin may be blended in an amount of 0.1 ppb to 1000 ppm.

In this case, the content of the copolymerized diethylene glycol may be 1.0 to 5.0 mol% of the glycol component constituting the polyester.

In this case, the density of the polyester chips can be 1.37 g / cm ³ or more.
In this case, the acetaldehyde content is 10p
pm or less. In this case, the content of the cyclic trimer can be 0.50% by weight or less.

In this case, in the chipping step after the melt polycondensation, the content of sodium, magnesium, silicon and calcium in the cooling water is changed to N, M, S and C, respectively. In this case, the chip can be formed using cooling water satisfying at least one of the following (1) to (4). N ≦ 1.0 (ppm) (1) M ≦ 0.5 (ppm) (2) S ≦ 2.0 (ppm) (3) C ≦ 1.0 (ppm) (4)

In this case, the hollow molded body is
It can be obtained by molding the polyester described above. In this case, the sheet-like material may be formed by molding the above-mentioned polyester. Furthermore, in this case, the stretched film may be formed by stretching the sheet-like material in at least one direction.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the polyester of the present invention and hollow molded articles, sheets and stretched films comprising the same will be described in detail. The polyester of the present invention is a polyester whose main repeating unit is ethylene terephthalate, is preferably a linear polyester containing at least 85 mol% of ethylene terephthalate units, more preferably at least 90 mol%. Particularly preferred is a linear polyester containing 95% mol or more.

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

The glycol used as a copolymer component when the polyester is a copolymer includes diethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol and the like. Examples include aliphatic glycols, alicyclic glycols such as cyclohexanedimethanol, aromatic glycols such as bisphenol A, and alkylene oxide adducts of bisphenol A, and the like.

Further, as the polyfunctional compound as a copolymer component used when the polyester is a copolymer, trimellitic acid, pyromellitic acid, etc. may be mentioned as an acid component. Glycerin and pentaerythritol can be mentioned as components. The amount of the above-mentioned copolymer component to be used must 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 polyester can be produced by a conventionally known production method. That is, in the case of PET, a low-order condensate obtained by directly reacting terephthalic acid with ethylene glycol and, if necessary, other copolymerization components to distill water and esterification is subjected to polycondensation under reduced pressure. The low-order condensate obtained by direct esterification, or by reacting dimethyl terephthalate with ethylene glycol and, if necessary, other copolymerization components, distilling off methyl alcohol and transesterifying, is obtained under reduced pressure. It is produced by a transesterification method in which polycondensation is performed. If necessary, solid-state polymerization may be performed in order to increase the intrinsic viscosity and reduce the acetaldehyde content and the like. In order to promote crystallization before solid-phase polymerization, the melt-polymerized polyester may be heated and then crystallized after moisture absorption, or steam may be directly blown onto the polyester chip for heat crystallization.

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

The present inventors have conducted intensive studies on the relationship between the properties of PET and mold contamination in order to obtain a PET hollow molded article having excellent transparency and heat resistance. It has been found that, when a heat-resistant hollow molded article is molded using 50,000 PET, the main components of the stain adhering to the mold are a low molecular weight PET having a number average molecular weight of about 5,000 to 10,000 and a cyclic trimer. Based on these facts, when the outer layer of the body wall of the molded body being stretch blown comes into contact with the surface of the stretch blow mold heated to about 140 ° C to 160 ° C, it is present in the PET. The low molecular weight PET component is melted and adhered little by little to the heating mold, and the low molecular weight PET has a melting point of 30 in the hollow molded body.
It is presumed that a cyclic oligomer such as a cyclic trimer having a temperature of 0 ° C. or higher is taken in and becomes a main component of the adhesion to the mold. That is, it is presumed that low-molecular-weight PET may function as an adhesive for attaching a cyclic trimer or the like to the mold surface. Such deposits mainly composed of low-molecular-weight PET and cyclic trimer are firmly accumulated on the surface of the heated mold during continuous molding for a long period of time, so that the mold surface, which has been in a mirror-like state at the start of molding, is formed. It became uneven with the passage of time, and it was found that this uneven pattern was transferred to the surface of the hollow molded article, and the transparency of the hollow molded article was reduced.

Based on the above considerations, the present inventors have conducted various studies for the purpose of developing a polyester in which the outer layer of a hollow molded article in contact with a heating mold has an improved heat-sealing property, and have reached the present invention. The polyester of the present invention is a polyester whose main repeating unit is composed of ethylene terephthalate, and is a heat treatment of a molded article obtained from the polyester, which is measured under the following conditions by a differential scanning calorimeter (DSC). The crystallization temperature (Tc) at the time of the subsequent temperature rise is 120 ° C.
A polyester having a range of from 150 to 150 ° C, preferably from 125 to 145 ° C, more preferably from 130 to 140 ° C. When the crystallization temperature (Tc) at the time of temperature rise after the heat treatment is less than 120 ° C., there is an effect on mold fouling, but the crystallization rate of the polyester is too fast, and the plug portion of the obtained hollow molded body has Crystallization becomes excessive and the shrinkage amount of the plug does not fall within the specified value range, resulting in poor capping of the plug and leakage of the contents, and the transparency of the body deteriorates, resulting in poor commercial value. Disappears. On the other hand, if the crystallization temperature (Tc) at the time of temperature rise after heat treatment exceeds 150 ° C., the crystallization speed of the polyester is insufficient, so that the preform of the hollow molded body is preheated, and then the biaxial stretching blow is performed. During molding, the crystallization of the surface layer of the body wall of the hollow molded article becomes insufficient, and when the surface layer of the hollow molded article comes into contact with the heating mold, the low molecular weight PET of the surface layer melts into the heating mold. The mold is contaminated and accumulated on the surface of the mold, and as a result, mold contamination during continuous molding becomes severe, and as a result, the transparency of the hollow molded body deteriorates. And it takes time to remove mold dirt,
Productivity drops significantly.

The crystallization temperature (Tc) at the time of temperature rise after the heat treatment of the molded product was 1 measured by a differential scanning calorimeter (DSC).
In the case of the polyester of the present invention in the range of 20 ° C. to 150 ° C., crystallization of the surface layer of the body wall of the hollow molded body during stretch blow molding of the obtained preformed body in a heating mold. The amount of low molecular weight PET adhered to the heating mold is very small, and therefore the amount of cyclic trimer attached is very small. Therefore, the transparency of the hollow molded article obtained after continuous molding for a long time is also good.

The polyester of the present invention has a crystallization temperature (Tc1) in the range of 150 ° C. to 175 ° C., preferably 155 ° C., when the obtained molded product is measured by a differential scanning calorimeter (DSC) when the temperature is raised. C. to 173C. When the crystallization temperature (Tc1) at the time of temperature rise is less than 150 ° C., the crystallization rate at the time of heating becomes fast, and the crystallization of the plug portion of the hollow molded container becomes excessive, and therefore, the shrinkage amount of the plug portion Does not fall within the specified value range, so that capping of the plug portion becomes defective and leakage of contents occurs. In addition, the preform for hollow molding is whitened, which makes normal stretching impossible,
Thickness unevenness occurs, and the crystallization rate is high, so that the obtained hollow molded article has poor transparency and large fluctuations in transparency. When the crystallization temperature (Tc1) at the time of temperature rise exceeds 175 ° C., the crystallization speed becomes very slow. Therefore, when the plug portion of the hollow molded article is crystallized, crystallization is insufficient, and the shrinkage of the plug portion does not fall within the specified value range, resulting in poor capping.

The polyester of the present invention has a molded article having a haze of 15% or less. If the haze of the molded body exceeds 15%, the transparency of the obtained molded body becomes poor, which is problematic.

The polyester of the present invention can be produced, for example, as follows, but is not limited thereto. That is, the polyester of the present invention is obtained by adding a talc, kaolin, silica, titanium oxide, or titanium oxide having an average particle size of 20 μm or less, preferably 10 μm or less, preferably 5 μm or less to a polyester whose main repeating unit is composed of ethylene terephthalate. 0.1 to 90 ppb, preferably 0.5 to 60 ppb, of at least one compound selected from sodium salts of organic acids such as terephthalic acid and benzoic acid;
ppb, more preferably 1 to 50 ppb.

The above compounds can be added at any stage before the polyester is molded. For example, a method of adding at any time until the end of melt polycondensation of polyester, a method of blending by making a high-concentration master batch, and mixing with polyester by a mixer such as a tumbler blender and melt-kneading using an extruder. And the like.

Hereinafter, an example of a preferable production method in a continuous system will be described using polyethylene terephthalate as an example. First, a case where a low polymer is produced by an esterification reaction will be described. A slurry containing 1.02 to 1.5 moles, preferably 1.03 to 1.4 moles of ethylene glycol per 1 mole of terephthalic acid or an ester derivative thereof was prepared, and this was subjected to an esterification reaction. Feed continuously to the process.

In the esterification reaction, water or alcohol produced by the reaction is rectified under a condition in which ethylene glycol is refluxed using a multistage apparatus in which at least two esterification reactors are connected in series. It is carried out while removing the system outside the column. The temperature of the first stage esterification reaction is 240 ~
270 ° C, preferably 245-265 ° C, pressure 0.2
３3 kg / cm ² G, preferably 0.5-2 kg / cm ²
G. The temperature of the final esterification reaction is usually 25.
The temperature is 0 to 280 ° C, preferably 255 to 275 ° C, and the pressure is usually 0 to 1.5 kg / cm ² G, preferably 0 to 1.
It is 3 kg / cm ² G. When the reaction is carried out in three or more stages, the reaction conditions for the esterification reaction in the intermediate stage are the above-mentioned first conditions.
This is a condition between the reaction condition of the stage and the reaction condition of the final stage. The increase in the conversion of these esterification reactions is preferably distributed smoothly at each stage. Finally, the esterification reaction rate is 90% or more, preferably 93%.
It is desirable to reach the above. A low-order condensate having a molecular weight of about 500 to 5,000 is obtained by these esterification reactions. When terephthalic acid is used as a raw material, the esterification reaction can be carried out without a catalyst by the catalytic action of terephthalic acid as an acid, but may be carried out in the presence of a polycondensation catalyst.

Also, tertiary amines such as triethylamine, tri-n-butylamine, benzyldimethylamine, tetraethylammonium hydroxide,
When a small amount of a quaternary ammonium hydroxide such as n-butylammonium and trimethylbenzylammonium hydroxide and a basic compound such as lithium carbonate, sodium carbonate, potassium carbonate and sodium acetate are added, the reaction of polyethylene terephthalate is reduced. It is preferable because the ratio of the dioxyethylene terephthalate component unit in the chain can be kept at a relatively low level (5 mol% or less based on all diol components).

Next, when a low polymer is produced by a transesterification reaction, 1.1 to 1.6 moles, preferably 1.2 to 1.5 moles of ethylene glycol are added to 1 mole of dimethyl terephthalate. Is prepared and continuously supplied to the transesterification step.

In the transesterification reaction, methanol produced by the reaction is passed through a rectification column under conditions in which ethylene glycol is distilled back using a device in which one or two transesterification reactors are connected in series. Perform while removing outside the system. The temperature of the first-stage transesterification reaction is 180 to 250 ° C, preferably 200 to 240 ° C. The temperature of the final transesterification reaction is usually 230 to 270 ° C., preferably 24 to 270 ° C.
0 to 265 ° C., and as a transesterification catalyst, Zn,
Fatty acid salts such as Cd, Mg, Mn, Co, Ca, and Ba;
Carbonate, Pb, Zn, Sb, Ge oxide or the like is used. By these transesterification reactions, the molecular weight is about 200 to 500.
A low degree of condensate is obtained.

Next, the obtained low-order condensate is supplied to a multi-stage liquid phase condensation polymerization step. The polycondensation reaction conditions are as follows: the reaction temperature of the first stage polycondensation is 250 to 290 ° C, preferably 260 to 280 ° C, and the pressure is 500 to 20 Torr.
r, preferably 200 to 30 Torr, and the temperature of the final polycondensation reaction is 265 to 300 ° C, preferably 275
To 295 ° C., and the pressure is 10 to 0.1 Torr, preferably 5 to 0.5 Torr. When the reaction is carried out in three or more stages, the reaction conditions for the polycondensation reaction in the intermediate stage are those between the above-mentioned first-stage reaction conditions and the last-stage reaction conditions. It is preferred that the degree of increase in the intrinsic viscosity reached in each of these polycondensation reaction steps be distributed smoothly.

The polycondensation reaction is performed using a polycondensation catalyst.
A compound of Ge, Sb, Ti, or Al is used, but a Ge compound or a compound thereof and a Ti compound, or a Ge compound or a mixture thereof with an Al compound is particularly convenient. These compounds are added to the reaction system as a powder, an aqueous solution, an ethylene glycol solution, a slurry of ethylene glycol, and the like.

As the Ge compound, amorphous germanium dioxide, crystalline germanium dioxide powder or a slurry of ethylene glycol, a solution in which crystalline germanium dioxide was dissolved by heating in water, or ethylene glycol was added thereto and heat-treated. Although solution or the like is used, especially in obtaining the polyester used in the present invention, the ratio D (a absorbance of 550 cm ^-1 in the infrared absorption spectrum absorbance of 515 cm ^-1 with respect to (A550cm ^-1) (A515cm ^-1)
515 cm ^-1 / A 550 cm ^-1 ) is 0.70 to 0.2
It is preferred to use 0 crystalline germanium dioxide. By using crystalline germanium dioxide having such properties, the polyester of the present invention can be produced more advantageously.

These polycondensation catalysts can be added at any stage after the completion of the polycondensation from the esterification step.
In particular, it is preferable to add it after completion of the polycondensation reaction. When a Ge compound is used, the amount of the compound used is G
e 10 to 150 ppm as residual amount, preferably 13 to 150 ppm
It is 100 ppm, more preferably 15 to 70 ppm.

Examples of the Ti compound include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate and tetra-n-butyl titanate, and partial hydrolysis thereof. Products, titanyl oxalate, titanyl ammonium oxalate, sodium titanyl oxalate, potassium titanyl oxalate, titanyl calcium oxalate, titanyl strontium oxalate, and the like, titanium trimellitate, titanium sulfate, titanium chloride, and the like. The Ti compound is formed polymer
It is added so that the remaining amount of Ti therein is in the range of 0.1 to 10 ppm.

As the Sb compound, antimony trioxide,
Antimony acetate, antimony tartrate, antimony potassium tartrate, antimony oxychloride, antimony glycolate
And antimony pentoxide, triphenylantimony and the like. The Sb compound is added so that the amount of Sb remaining in the resulting polymer is in the range of 5 to 200 ppm.
Further, as the Al compound, aluminum formate, aluminum acetate, aluminum propionate, carboxylate such as aluminum oxalate, oxide, aluminum hydroxide,
Inorganic acid salts such as aluminum chloride, aluminum hydroxide chloride and aluminum carbonate; aluminum alkoxides such as aluminum methoxide and aluminum ethoxide; aluminum chelates with aluminum acetylacetonate and aluminum acetyl acetate; And organoaluminum compounds such as trimethylaluminum and triethylaluminum, and their partially hydrolyzed products. Of these, aluminum acetate,
Aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, and aluminum acetylacetonate are particularly preferred. The Al compound is an Al compound in the resulting polymer.
It is added so as to have a residual amount of 5 to 200 ppm.

In the case of an Al compound, an alkali metal compound or an alkaline earth metal compound may be used in combination. The alkali metal compound or alkaline earth metal compound includes carboxylate such as acetate of these elements, alkoxide and the like, and is added to the reaction system as powder, aqueous solution, ethylene glycol solution and the like. The alkali metal compound or alkaline earth metal compound is added so that the residual amount of these elements in the produced polymer is in the range of 1 to 50 ppm.

Various P compounds can be used as a stabilizer. Examples of the P compound used in the present invention include phosphoric acid, phosphorous acid, and derivatives thereof. Specific examples include phosphoric acid, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, monomethyl phosphate, dimethyl phosphate, monobutyl phosphate, dibutyl phosphate, and dibutyl phosphate. Phosphoric acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, etc., which may be used alone or in combination of two or more.
The P compound is 1 to 10 as a residual amount of P in the produced polymer.
It can be added at any stage of the polyester production reaction step so as to be in the range of 00 ppm.

The molten polyester obtained from the final polycondensation reactor is extruded into water from a die and cut in water, or extruded into the atmosphere and immediately cut while cooling with cooling water. And the like. In order to produce the polyester of the present invention,
When the content of sodium, the content of magnesium, the content of silicon, and the content of calcium in the cooling water in the chipping process are N, M, S, and C, respectively,
It is preferred that the melt polycondensation polyester is formed into chips so as to satisfy at least one of (4) and further all of them. N ≦ 1.0 (ppm) (1) M ≦ 0.5 (ppm) (2) S ≦ 2.0 (ppm) (3) C ≦ 1.0 (ppm) (4)

By setting the contents of sodium, magnesium, calcium, and silicon in the chip cooling water within the above range, these metal-containing compounds adhere to and penetrate the polyester resin chip, and as a result, the crystal during molding is formed. Is promoted, and a bottle with poor transparency can be prevented.

The shape of the polyester chip is a cylinder
Any of a mold, a square, a sphere or a flat plate may be used. The average particle size is usually 1.5 to 5 mm, preferably 1.6 to 5 mm.
It is 4.5 mm, more preferably in the range of 1.8 to 4.0 mm. For example, in the case of a cylinder type, the length is 1.
It is practical that the diameter is about 5 to 4 mm and the diameter is about 1.5 to 4 mm. 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. The weight of the chip is 1
A range of 5-30 mg / piece is practical.

Further, when a low acetaldehyde content or a low cyclic trimer content is required, such as in a low-flavor beverage heat-resistant container or a film for the inner surface of a metal can for beverage, etc. The obtained melt-polycondensed polyester is subjected to solid-state polymerization. The polyester is subjected to solid-state polymerization by a conventionally known method. First, the polyester to be subjected to solid-state polymerization is treated under an inert gas or under reduced pressure or under an atmosphere of steam or an inert gas containing steam.
It is pre-crystallized by heating at a temperature of 00 to 210 ° C. for 1 to 5 hours. Then, under an inert gas atmosphere or reduced pressure, 19
The solid state polymerization is carried out at a temperature of 0 to 230 ° C. for 1 to 30 hours.

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

The content of such fines in the polyester of the present invention is preferably 0.1 to 300 pp.
m, more preferably 0.2 to 250 ppm. When the compounding amount is less than 0.1 ppm, the crystallization speed becomes very slow, and the crystallization of the plug portion of the hollow molded article becomes insufficient, so that the shrinkage amount of the plug portion falls within the specified value range. As a result, poor capping occurs, and a stretched heat-fixing mold for molding a heat-resistant hollow molded article is heavily contaminated, and frequent cleaning is required to obtain a transparent hollow molded article. When the content exceeds 300 ppm, the crystallization rate is increased, and the crystallization of the plug portion of the hollow molded article becomes excessive. Therefore, the shrinkage amount of the plug portion does not fall within the specified value range, so that the capping of the plug portion is performed. Failure and leakage of the contents occur, and the preform for hollow molding whitens,
This makes normal stretching impossible.

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

In the present invention, as a method for adjusting the fine content of the polyester to the above-mentioned range, a high fine-content PET chip which has not been passed through the sieving step is passed through a sieving step and a fine removing step by an air flow. In addition to the method of mixing PET chips having a very small fine content at an appropriate ratio, the fine chips can also be adjusted by changing the opening of the decoration in the fine removal step, or by changing the sieving speed, etc. Any method can be used. Further, the polyester of the present invention
The amount of increase of the cyclic trimer when melted at a temperature of 90 ° C. for 60 minutes is 0.30% by weight or less. The amount of increase of the cyclic trimer is preferably 0.2% by weight or less, more preferably 0.1% by weight or less. 60 at a temperature of 290 ° C
0.30% by weight of cyclic trimer when melted for 3 minutes
Is exceeded, the amount of the cyclic trimer increases when the resin for molding is melted, and the adhesion of the oligomer to the surface of the heating mold rapidly increases,
The transparency of the obtained hollow molded article or the like is extremely deteriorated.

The polyester of the present invention in which the amount of the cyclic trimer increased by 0.30% by weight or less when melted at a temperature of 290 ° C. for 60 minutes was obtained from the polyester obtained after the melt polycondensation or after the solid phase polymerization. It can be produced by deactivating the polycondensation catalyst. Examples of the method for deactivating the polyester polycondensation catalyst include a method of subjecting a polyester chip to contact treatment with water, steam or a steam-containing gas after melt polycondensation or after solid-phase polymerization.

A method for contacting a polyester chip 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 water and a method of spraying water on a chip 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 water temperature is 20 to 180 ° C, preferably 40 to 180 ° C.
To 150 ° C, more preferably 50 to 120 ° C.

The following is an example of a method for industrially performing water treatment, but the method is not limited thereto. The treatment method may be either a continuous method or a batch method, but the continuous method is preferable for industrial use. When water treatment of polyester chips in batch mode,
Silo-type processing tanks are exemplified. That is, the chips of the polyester are received in the silo in a batch system and water treatment is performed. In the case of treating the polyester chips with water in a continuous manner, the polyester chips can be continuously or intermittently received in the tower-type treatment tank from above and subjected to water treatment. This conceptual diagram is shown in FIG.

Regardless of whether the method of water treatment is continuous or batch, if all or most of the treated water discharged from the treatment tank is converted into industrial wastewater, a large amount of fresh water is required. In addition, there is a concern about the impact on the environment due to increased wastewater volume. That is, at least a part of the treated water discharged from the treatment tank is returned to the water treatment tank and reused, thereby reducing the required amount of water and reducing the effect on the environment by increasing the amount of wastewater. If the wastewater returned to the water treatment tank maintains a certain temperature,
Since the heating amount of the treated water can be reduced, the treated water discharged from the treated layer is preferably returned to the water treated layer and reused. Also, by reusing the water, the flow rate of the treated water in the treated layer can be increased, and as a result, the fines attached to the polyester chip can be washed away,
Also produces a fine removal effect. Here, the treated water that is discharged from the water treatment tank, returned to the treatment tank again, and reused includes water discharged from the overflow port of the water treatment tank and polyester chips from the treatment tank. There is treated water discharged and then separated from the chips.

However, the treated water discharged from the treatment tank in the water treatment contains fines that have already adhered to the polyester chips at the stage of receiving the polyester chips in the treatment tank, the polyester chips between the polyester chips during the water treatment, or the walls of the treatment tank. Contains fines of polyester generated by friction. In addition, fresh treated water contains fine particles derived from inorganic substances, organic fine particles derived from spoiled plants and animals, and the like.

Therefore, when the treated water discharged from the treatment tank is returned to the treatment tank again and reused, the amount of fines and fine particles contained in the treated water in the treatment tank gradually increases and is contained in the treated water. Fines and fine particles sometimes adhere to the processing tank wall and the pipe wall, and clog the pipe.

Further, fines and fine particles contained in the treated water adhere to the polyester chip, and then the fines and fine particles adhere to or penetrate the polyester chip at the stage of drying and removing the water. The content becomes very large, and the polyester obtained in this way is promoted in crystallinity, the transparency of the obtained bottle is deteriorated, and the crystallinity at the time of crystallization of the bottle plug is too large. As a result, the dimensions of the plug part did not meet the standard, which sometimes resulted in poor capping of the plug part and leakage of the contents.

Therefore, in the present invention, after being discharged from the water treatment tank, at least a part thereof is returned to the treatment tank again, and the particle size present in the treated water to be recycled is 1 to 40 μm.
m of particles of 100,000 particles / 10 ml or less, preferably 80,000 particles / 10 ml or less, more preferably 500
It is desirable to keep the number at or below 00/10 ml. Here, the treated water returned to the treatment tank and reused in this way is referred to as recycled water.

The particle size of the recycled water is 1 to 40
A method for reducing the number of particles of μm to 100,000 / 10 ml or less will be exemplified, but the present invention is not limited thereto. The number of particles having a particle size of 1 to 40 μm
As a method of reducing the volume to 10 ml or less, an apparatus for removing fines and fine particles is provided at at least one place in the process until the treated water discharged from the treatment tank is returned to the treatment tank again. Examples of devices for removing fines and fine particles include a filter-filtration device, a membrane filtration device, a sedimentation tank, a centrifugal separator, and a foam entrainer. For example, in the case of a filter-filtration apparatus, examples of the method include a filtration apparatus such as an automatic self-cleaning method, a belt filter method, a bag filter method, a cartridge filter method, and a centrifugal filtration method. Above all, a belt filter system, a centrifugal filtration system, and a bag filter system are suitable for continuous operation. In the case of a belt filter type filtration device, examples of the filter medium include paper, metal, cloth, and the like. Also, in order to efficiently remove fines and flow the treated water, the size of the filter eyes is 5 to 100 μm, preferably 5 to 70 μm.
More preferably, the thickness is 5 to 40 μm.

Further, the water introduced from outside the system is discharged together with the chips from the water treatment tank, and then supplied to the treatment tank together with the treated water to be reused after being subjected to a treatment such as filtration. is there.

When the polyester chips are brought into contact with steam or a steam-containing gas 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 in an amount of 0.5 g or more as steam per kg of granular polyethylene terephthalate. The granular polyethylene terephthalate is brought into contact with steam. The contact between the polyester chips and water vapor is usually performed for 10 minutes to 2 days, preferably for 20 minutes to 10 days.
Done for hours.

The method of industrially carrying out the contact treatment of granular polyethylene terephthalate with water vapor or a gas containing water vapor is exemplified below, but the method is not limited to this. The processing method may be either a continuous method or a batch method.

When a polyester chip is subjected to a contact treatment with steam in a batch system, a silo-type treatment apparatus may be used. That is, a polyester chip is received in a silo, and steam or a steam-containing gas is supplied in a batch system to perform a contact treatment.

When the polyester chips are continuously subjected to the contact treatment with steam, the granular polyethylene terephthalate is continuously received in the tower-type treatment apparatus from above, and the steam is continuously supplied in parallel or countercurrent to contact with the steam. Can be processed.

As described above, when treated with water or steam, the granular polyethylene terephthalate is drained, if necessary, with a draining device such as a vibrating sieve or a simmon carter, and then 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 continuous drying, a hopper-type through-air dryer that supplies a polyester chip from the upper portion and allows a drying gas to flow from the lower portion is usually used.

As a dryer for drying in a batch system, drying may be performed under atmospheric pressure while passing a drying gas. As the dry gas, atmospheric air may be used, but dry nitrogen and dehumidified air are preferred from the viewpoint of preventing a reduction in molecular weight due to hydrolysis or thermal oxidative decomposition of the polyester.

The polyester of the present invention is obtained by adding at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin, a polyacetal resin and a polybutylene terephthalate resin to the polyester described above.
It is a polyester characterized by blending from pb to 1000 ppm. At least one resin selected from the group consisting of polyolefin resin, polyamide resin, polyacetal resin, and polybutylene terephthalate resin in the polyester of the present invention (hereinafter, may be abbreviated as "thermoplastic resin"). ) Is 0.1ppb
~ 1000ppm, preferably 0.3ppb ~ 100p
pm, more preferably 0.5 ppb to 1 ppm, even more preferably 0.5 ppb to 45 pbb. If the compounding amount is less than 0.1 ppb, the crystallization rate becomes extremely slow, and the crystallization of the plug portion of the hollow molded article becomes insufficient. The capping is poor because it does not fall within the value range, and the stretch heat-fixing mold for molding the heat-resistant hollow molded article is heavily stained, and frequent cleaning is required to obtain a transparent hollow molded article. There must be. Also 1000pp
In the case of exceeding m, the crystallization speed becomes fast, and the crystallization of the plug portion of the hollow molded article becomes excessively large, so that the shrinkage and shrinkage amount of the plug portion does not fall within the specified value range, resulting in poor capping and the content. Leakage, or whitening of the preform for a hollow molded body, making normal stretching impossible. In the case of a sheet-like material, if it exceeds 1000 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. I can't. In addition, it has been found that the use of the thermoplastic resin alone has little effect on the prevention of heating mold stains, but has a great effect on mold stains due to coexistence with a specific amount of fines.

Examples of the polyolefin resin blended in the polyester of the present invention include a polyethylene resin, a polypropylene resin, and an α-olefin resin.

Examples of the polyethylene resin blended in the polyester of the present invention include, for example, ethylene homopolymer, ethylene, propylene, butene-1, 3-methylbutene-1, pentene-1, and 4-methylpentene-1. ,
Carbon number 2 such as hexene-1, octene-1 and decene-1
And about 20 other α-olefins and copolymers with vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic acid esters, methacrylic acid esters, and styrene. Specifically, for example, ethylene homopolymers such as low / medium / high density polyethylene (branched or linear), ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-4-methyl Pentene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene -Ethylene resins such as ethyl acrylate copolymer.

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

Further, α to be added to the polyester of the present invention
-As the olefin resin, 4-methylpentene-1
A homopolymer of an α-olefin having about 2 to 8 carbon atoms, such as
These α-olefins and carbon atoms having 2 to 2 carbon atoms such as ethylene, propylene, butene-1, 3-methylbutene-1, pentene-1, hexene-1, octene-1, and decene-1.
Copolymers with about 0 other α-olefins and the like can be mentioned. Specifically, for example, butene-1 homopolymer,
Butene-1 based resins such as methylpentene-1 homopolymer, butene-1-ethylene copolymer, butene-1-propylene copolymer, and 4-methylpentene-1 and α of C ₂ -C ₁₈ .
-Copolymers with olefins, and the like.

The polyamide resin blended in the polyester of the present invention includes, for example, butyrolactam, δ
Lactam polymers such as valerolactam, ε-caprolactam, enantholactam, ω-laurolactam,
Aminocaproic acid, 11-aminoundecanoic acid, 12-
Polymer of aminocarboxylic acid such as aminododecanoic acid, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, undecamethylenediamine, 2,2,4- or 2,4,4-trimethylhexamethylenediamine Aliphatic diamines such as 1,3
-Or 1,4-bis (aminomethyl) cyclohexane,
An alicyclic diamine such as bis (p-aminocyclohexylmethane), a diamine unit such as an aromatic diamine such as m- or p-xylylenediamine, and glutaric acid, adipic acid;
Polycondensates with dicarboxylic acid units such as aliphatic dicarboxylic acids such as suberic acid and sebacic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and copolymers thereof. And specifically, for example, 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 MXD6, nylon 6/66, nylon 6/610, nylon 6/12, nylon 6 / 6T, nylon 6I / 6T and the like.

The polyacetal resin blended in the polyester of the present invention includes, for example, polyacetal homopolymers and copolymers. As the polyacetal homopolymer, the density measured by the measuring method of ASTM-D792 is 1.40 to 1.42 g / cm ³ ,
According to the measuring method of D-1238, 190 ° C., load 2160
The melt flow ratio (MFR) measured in g is 0.5 to 50.
Polyacetals in the range of g / 10 minutes are preferred.

The polyacetal copolymer includes:
The density measured by the method of ASTM-D792 is 1.
A polyacetal copolymer having a melt flow ratio (MFR) measured at a temperature of 190 ° C. and a load of 2160 g in a range of 0.4 to 50 g / 10 minutes by a method of measuring 38 to 1.43 g / cm ³ and ASTM D-1238 is obtained. preferable. Examples of these copolymer components include ethylene oxide and cyclic ether.

The polybutylene terephthalate resin blended in the polyester of the present invention includes, for example, a polybutylene terephthalate homopolymer composed of terephthalic acid and 1,4-butanediol, and naphthalene dicarboxylic acid. Copolymers obtained by copolymerizing an acid, diethylene glycol, 1,4-cyclohexanedimethanol, and the like are included.

Further, the production of the polyester blended with a thermoplastic resin in the present invention may be carried out by directly adding and melting and kneading the thermoplastic resin to the polyester so that the content is within the above range, or In addition to a conventional method such as a method of adding and melting and kneading as a master batch, the above thermoplastic resin is produced at the polyester production stage, for example, at the time of melt polycondensation, immediately after melt polycondensation, immediately after pre-crystallization, and solid phase. During polymerization, any stage such as immediately after solid-phase polymerization, or during the period from the end of the manufacturing stage to the molding stage, etc., directly added as powders or in the flow condition of polyester chips It is also possible to employ a method of mixing the mixture by, for example, bringing it into contact with the above-mentioned thermoplastic resin member and then melt-kneading the mixture.

Here, at least one kind of resin member selected from the group consisting of a polyolefin resin, a polyamide resin, a polyacetal resin, and a polybutylene terephthalate resin is brought into contact with the polyester chip under the flow conditions. As a method, in the space where the member made of the thermoplastic resin is present, it is preferable that the polyester chip is brought into collision with the member, specifically, for example, immediately after melt polycondensation of the polyester, immediately after pre-crystallization. , Pneumatic transport piping during the manufacturing process immediately after solid-phase polymerization, etc., during filling and discharging of transport containers during the transport stage of polyester chips as a product, and during injection of a molding machine during the polyester chip molding stage, etc. , Gravity transport pipe, silo, part of the magnet part of the magnet catcher or the like is made of the thermoplastic resin, Alternatively, a method of transferring the polyester chip by lining the thermoplastic resin or disposing the thermoplastic resin member having a melting point such as a rod-like or net-like body in the transfer path, or the like, may be used. .
The contact time of the polyester chip with the member is usually
Although it is an extremely short time of about 0.01 seconds to several minutes, a small amount of the thermoplastic resin can be mixed into the polyester.

The intrinsic viscosity of the polyester of the present invention is preferably from 0.55 to 0.90 deciliter / gram, more preferably from 0.58 to 0.88 deciliter / gram,
More preferably, it is in the range of 0.60 to 0.86 deciliter / gram. The limiting viscosity is 0.55 deciliter /
When the amount is less than gram, the mechanical properties of the obtained molded article or the like are poor. On the other hand, if it exceeds 0.90 deciliter / gram, the resin temperature rises during melting by a molding machine or the like, and the thermal decomposition becomes severe. Problems such as yellowing occur.

The acetaldehyde content of the polyester of the present invention is preferably 8 ppm or less, more preferably 6 ppm or less, further preferably 4 ppm or less, and the formaldehyde content is preferably 6 ppm or less, more preferably 5 ppm or less, and further preferably 4 ppm or less. It is as follows. If the acetaldehyde content is 8 ppm or more and the formaldehyde content is 6 ppm or more, the contents such as containers and the like molded from the polyester deteriorate in flavor and odor.

The amount of diethylene glycol copolymerized in the polyester of the present invention is preferably 1.0 to 5.0 mol%, more preferably 1.3 to 4.0 mol% of the glycol component constituting the polyester. It is 5 mol%, and more preferably 1.5 to 4.0 mol%. When the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability becomes poor,
The decrease in molecular weight during molding is large, and the acetaldehyde content and the formaldehyde content are undesirably large. When the content of diethylene glycol is less than 1.0 mol%, the transparency of the obtained molded article is deteriorated.

The content of the cyclic trimer of the polyester of the present invention is preferably 0.50% by weight or less, more preferably 0.40% by weight or less, further preferably 0.35% by weight or less. When a heat-resistant hollow molded article or the like is molded from the polyester of the present invention, heat treatment is performed in a heating mold. However, when the content of the cyclic trimer is 0.50% by weight or more, the heating mold is used. Adhesion of the oligomer to the surface increases sharply, and the transparency of the obtained hollow molded article or the like becomes very poor.

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

Examples of the saturated fatty acid monoamide include lauric amide, palmitic amide, stearic amide, behenic amide and the like. Examples of unsaturated fatty acid monoamides include oleamide, erucamide, ricinoleamide, and the like. Examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid Amides and the like. Examples of the unsaturated fatty acid bisamide include ethylene bisoleic acid amide and hexamethylene bisoleic acid amide. Preferred amide compounds are saturated fatty acid bisamide, unsaturated fatty acid bisamide and the like. The compounding amount of such an amide compound is 1
The range is from 0 ppb to 1 × 10 ⁵ ppm.

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

The polyester of the present invention can be preferably used as a hollow molding, a tray, a packaging material such as a biaxially stretched film, a film for covering a metal can, and the like. Further, the polyester of the present invention can be used for producing a multilayer molded product or a multilayer film.
It can also be used as a constituent layer.

The polyester of the present invention can be used to form films, sheets, containers and other packaging materials by using a commonly used melt molding method. In addition, mechanical strength can be improved by stretching PET at least in a uniaxial direction. The stretched film made of PET of the present invention is obtained by subjecting a sheet-like material obtained by injection molding or extrusion molding to any stretching method of uniaxial stretching, sequential biaxial stretching, and simultaneous biaxial stretching usually used for PET stretching. Molded using Further, it can be formed into a cup shape or a tray shape by pressure forming or vacuum forming.

In producing a stretched film, the stretching temperature is usually from 80 to 130 ° C. The stretching may be uniaxial or biaxial, but is preferably biaxial in view of practical physical properties of the film. The stretching ratio is usually 1.1 to 10 times, preferably 1.5 to 8 times in the case of uniaxial stretching. In the case of biaxial stretching, it is usually 1.1 to 8 times in both the longitudinal and transverse directions. , Preferably in the range of 1.5 to 5 times. The vertical / horizontal magnification is usually 0.5
２2, preferably 0.7。1.3. The obtained stretched film can be further heat-set to improve heat resistance and mechanical strength. Heat setting is usually under tension, 120 ° C
~ 240, preferably 150 ~ 230 ° C, usually several seconds ~
It is performed for several hours, preferably several tens seconds to several minutes.

In producing the hollow molded article, a briform molded from the PET of the present invention is stretch blow-molded, and an apparatus conventionally used for PET blow molding can be used. Specifically, for example, a preform is once molded by injection molding or extrusion molding, and after processing the plug portion and bottom portion, it is reheated, and biaxial stretch blow molding such as hot parison method or cold parison method is performed. The law applies. In this case, the molding temperature, specifically, the temperature of each cylinder and nozzle of the molding machine is usually in the range of 260 to 290 ° C. If the stretching temperature is usually 70 to 120 ° C, preferably 80 to 110 ° C,
The stretching ratio may be usually 1.5 to 3.5 times in the longitudinal direction and 2 to 5 times in the circumferential direction. The obtained hollow molded body is
Although it can be used as it is, especially in the case of beverages that require hot filling, such as fruit juice beverages and oolong tea,
Further, it is heat-fixed in a blow mold and further used with heat resistance. Heat fixation is usually under tension by compressed air.
It is carried out at a temperature of 00 to 200 ° C, preferably 120 to 180 ° C, for several seconds to several hours, preferably for several seconds to several minutes.

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

[0094]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.
The main method of measuring characteristic values in the present invention will be described below.

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

(2) Diethylene glycol content (hereinafter referred to as [DEG content]) Decomposed by methanol, the DEG content was determined by gas chromatography, and the ratio (mol%) to the total glycol components was determined. expressed.

(3) Acetaldehyde content (hereinafter referred to as “A
A) The sample / distilled water = 1 g / 2 ml was placed in a glass ampoule purged with nitrogen, the upper part was sealed, extracted at 160 ° C for 2 hours, and after cooling, the acetaldehyde in the extract was converted to a highly sensitive gas. The concentration was measured by chromatography and expressed in ppm.

(4) Content of Polyester Cyclic Trimer (CT Content) A sample is dissolved in a mixed solution of hexafluoroisopropanol / chloroform, and further diluted with chloroform. After adding methanol to precipitate a polymer, the mixture is filtered. The filtrate was evaporated to dryness, made up to a constant volume with dimethylformamide, and a cyclic trimer composed of ethylene terephthalate units was quantified by liquid chromatography.

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

(6) Fine Content Measurement About 0.5 kg of resin was placed on a screen (diameter 30 cm) with a wire mesh having a nominal size of 1.7 mm according to JIS-Z8801, and an oscillating screen sieve manufactured by Teraoka Co., Ltd. was used. 1 with tow machine SNF-7
Sieve at 800 rpm for 1 minute. This operation was repeated to sieve a total of 20 kg of the resin. The sieved fines were washed with ion-exchanged water and collected by filtration through a G1 glass filter manufactured by Iwaki Glass Co., Ltd. This was dried together with the glass filter in a dryer at 100 ° C. for 2 hours, cooled, and weighed. Again, repeat the same operation of washing and drying with ion-exchanged water,
After confirming that the weight became constant, the weight of the glass filter was subtracted from this weight to obtain a fine weight. Fine content is the fine amount / the total resin weight sieved.

(7) Average Density of Polyester Chip and Density of Parison Plug Portion The density was measured at 30 ° C. with a density gradient tube of calcium nitrate / water mixed solution.

(8) Haze (% haze) A sample was cut from the body (thickness: about 0.4 mm) of the molded article (thickness: 5 mm) and the hollow molded article (13) below, and the Measured with a haze meter NDH2000 manufactured by Color Corporation.

(9) Density increase due to heating of parison plug The parison plug is heated to 60% by a homemade infrared heater.
After heat treatment for 2 seconds, a sample was taken from the top surface and the density was measured.

(10) Molding of Stepped Molded Plate The dried polyester was prepared using M-150C (D
M) Molding is performed by an injection molding machine at a cylinder temperature of 290 ° C. using a stepped flat mold cooled to 10 ° C. The resulting stepped plates were 2, 3, 4, 5, 6, 7, 8,
A plate of about 3 cm x about 5 cm square with a thickness of 9, 10 and 11 mm is provided in a stepwise manner, and the weight of one piece is about 146
g. Plates having a thickness of 5 mm are used for measuring haze (haze%).

(11) Crystallization temperature (Tc) at the time of temperature rise after heat treatment of the molded article (Tc) Differential thermal analyzer (DSC) manufactured by Perkin-Elmer
Using 7C, the measurement was performed using a 10 mg sample from the center of the 2 mm thick plate of the step-formed plate of (10). The temperature is raised from room temperature to 90 ° C. at a temperature rising rate of 500 ° C./min, and after being treated at this temperature for 2.0 minutes, it is observed during the temperature rising to 180 ° C. at a temperature rising rate of 20 ° C./min. The temperature of the crystallization peak is defined as a crystallization temperature (Tc) at the time of temperature increase after the heat treatment. (12) Crystallization temperature (Tc1) at the time of temperature rise of the molded body Differential thermal analyzer (DS) manufactured by Seiko-Electronic Industries
C), measured with RDC-220. A 4 mg sample from the center of a 2 mm thick plate of the step-formed plate of (10) was used. The temperature was raised at a rate of temperature rise of 20 ° C./min, and the temperature of the crystallization peak observed in the course of the heating was measured and defined as the crystallization temperature during temperature rise (Tc1).

(13) Evaluation of mold stain The polyester was dried with a drier using nitrogen, and the resin temperature was set to 2 using an M-150C (DM) injection molding machine manufactured by Meiki Seisakusho.
A preform was formed at 90 ° C. After the plug portion of this preform was heated and crystallized with a home-made plug portion crystallizer, biaxial stretch blow molding was performed using a LB-01E stretch blow molding machine manufactured by Co-Poplast Co., Ltd. In a mold set for about 5 seconds to obtain a 500 cc hollow molded body. Under the same conditions, continuous stretch blow molding was performed, and the stain on the mold was evaluated by the number of moldings until the transparency of the container was impaired by visual inspection. Further, as a sample for haze measurement, a body portion of a container after continuous molding 5,000 times was provided.

(14) Evaluation of Leakage of Contents from Hollow Molded Article The hollow molded article molded in (13) above was filled with hot water at 90 ° C., capped by a capping machine, the container was turned over, and the contents were left to stand. Was examined for leaks. The deformation of the plug after capping was also examined.

(15) Absorbance at 550 cm ^-1 (A550 cm ^-1 ) in the infrared absorption spectrum of germanium dioxide
Absorbance of 515cm ^-1 that against the ^-1) (A515cm ^-1)
The ratio D (A515cm ^-1 / A550cm ^-1) Measurement 1) into tablets with an infrared absorption spectrum of about 400mg potassium bromide of the measurement sample of about 0.5mg of the ratio recording type infrared spectrophotometer (manufactured by Hitachi, Ltd. 27
0-30 type).

2) Calculation of Absorbance Ratio As shown in FIG. 1, the 515 cm ^-1 absorption band is at the upper and lower ends of the absorption band, and the 550 cm ^-1 absorption band is at the upper end of the absorption band and the lower end of the 515 cm ^-1 absorption band. Draw a tangent to each, and use the so-called base line method to determine the 515 cm ^-1 absorption band and 550 c
Absorbance of m ^-1 absorption band (A515 cm ^-1 and A550 cm
^-1 ), and the absorbance ratio D (A515 cm ^-1 / A5)
50 cm ^-1 ) was calculated.

Example 1 A slurry of high-purity terephthalic acid and ethyl glycol was continuously supplied to a first esterification reactor containing a reactant in advance, and the slurry was stirred for about 2 hours.
The reaction was carried out at 50 ° C. and 0.5 kg / cm ² G for an average residence time of 3 hours. This reaction product was sent to the second esterification reactor, and reacted under agitation at about 260 ° C. and 0.05 kg / cm ² G to a predetermined reactivity. The ratio D of absorbance at 550 cm ^-1 in the infrared absorption spectrum absorbance of 515 cm ^-1 with respect to (A550cm ^-1) (A515cm ^-1)
(A515 cm ^-1 / A550 cm ^-1 ) was prepared by dissolving 0.55 crystalline germanium dioxide in water by heating, adding ethylene glycol to this, heating-treating a catalyst solution, and a phosphoric acid ethylene glycol solution. To the reactant in the pipe at the outlet of the second esterification reactor.
This esterification reaction product is continuously fed to the first polycondensation reactor, and is stirred at about 265 ° C. and 25 torr for 1 hour, and then is stirred at about 265 ° C. in the second polycondensation reactor.
Torr for 1 hour and further with stirring in the final polycondensation reactor
Polycondensation was performed at about 275 ° C. and 0.5 to 1 torr for 1 hour. In a mixer installed after the final polycondensation reactor, a molten PET master in which talc having an average particle size of about 3 μm was dispersed was mixed so that the amount of talc added was as shown in Table 1, and then chips were formed. The cooling water used at the time of chipping has a sodium content of 0.01 ppm and a magnesium content of 0.1 ppm.
007 ppm, the calcium content was 0.01 ppm, and the silicon content was 0.05 ppm.

The obtained molten polycondensation PET was crystallized under a nitrogen atmosphere at about 155 ° C.
After preheating to 00 ° C, it was sent to a continuous solid-state polymerization reactor and subjected to solid-state polymerization at about 207 ° C under a nitrogen atmosphere. After the solid phase polymerization, fine treatment was continuously performed in a sieving process and a fine removing process to remove fines.

The intrinsic viscosity of the obtained PET was 0.74 deciliter / gram, the content of the cyclic trimer was 0.29% by weight, the density was 1.432 g / cm ³ , and the AA content was 2.9.
ppm, fine content was about 5 ppm. Fluorescent X
The residual amount of Ge measured by X-ray analysis is 44 ppm.
The remaining amount was 32 ppm. The Tc of the molded article obtained from PET was 135.8 ° C., and Tc1 was 162.8.
° C and the haze of the molded product was 5.3%. This PET was evaluated with a biaxially stretched bottle. Table 1 shows the results.

The density of the plug portion was 1.374 g / cm ³ , a value without any problem. Although continuous stretch blow molding of 5,000 or more pieces was carried out, no stain on the mold was observed, and the transparency of the bottle was poor. It was good. Further, the deformation of the bottle cap and the leakage of the contents after the contents filling test were examined, but no problem was found. The body haze of the bottle obtained after continuous molding 5,000 times was as good as 1.7%. In addition, the number of moldings up to mold contamination was 10,000, which was no problem. The AA content of the bottle was 18.8 ppm, which was a problem-free value.

Example 2 The solid-phase polymerized PET obtained in Example 1 was treated with water as follows. The apparatus shown in FIG. 2 is used for the water treatment of the PET chips. The raw material chip supply port (1) at the upper part of the processing tank, the overflow outlet (2) located at the upper limit level of the processing water in the processing tank, An outlet (3) for the mixture of polyester chips and treated water at the bottom of the treatment tank,
The treated water discharged from the bar flow outlet, the treated water discharged from the treatment tank, and the treated water discharged from the discharge section at the lower part of the treatment tank via the draining device (4) are made of paper. Pipe (6) sent again to the water treatment tank via the fine powder removing device (5) which is a continuous filter of the above, the inlet (7) of the treated water from which the fine powder has been removed, and the acetaldehyde in the treated water from which the fine powder has been removed. Tower (8) for adsorbing water and a new ion exchange water inlet (9) with a capacity of about 50
A 0-liter tower-type treatment tank was used.

After the above solid-state polymerization PET chips were washed with ion-exchanged water to remove fine and film-like substances, the chips were treated at a rate of 50 kg / hour in a water treatment tank controlled at a treated water temperature of 95 ° C. It was continuously charged from the supply port (1) in the upper part of the tank, and was continuously extracted together with the treated water at a rate of 50 kg / hour as a PET chip from the outlet (3) in the lower part of the treatment tank in two hours of the water treatment time. Particle size of recycled water after treatment in filtration device (5) and adsorption tower (8) is 1 to 40
The number of μm particles was about 10,000 / 10 ml. After the water treatment, fines and the like were removed in the vibrating sieve process and the airflow classification process. The sodium content of the ion-exchanged water for water treatment introduced from outside the system was 0.01 ppm, the magnesium content was 0.005 ppm, the calcium content was 0.008 ppm, and the silicon content was 0.04 ppm. As shown in Table 1, the molded article had a Tc of 138.3.
° C, Tc1 was 160.7 ° C, and the haze of the molded product was 5.5%. There was no problem in the evaluation of the deformation of the bottle cap and the leakage of the contents. The bottle body haze was as good as 1.9%, and the number of moldings up to mold contamination was 14,000, which was a satisfactory result.

Comparative Example 1 PET was produced in the same manner as in Example 1 except that amorphous germanium dioxide was used as a polycondensation catalyst and talc was not added. The residual amount of Ge measured by fluorescent X-ray analysis was 43 ppm, and the residual amount of P was 30 ppm. As shown in Table 1, the molded article had a Tc of 155.8 ° C., a Tc1 of 179.2 ° C., a molded article haze of 2.3%, and a density of the plug portion of 1.360.
g / cm ³ , insufficient crystallization. Deformation of the bottle cap and leakage of the contents after the content filling test were examined. Deformation of the bottle cap and leakage of the contents were observed. Was done. The bottle body haze after 5,000 continuous moldings was as bad as 8.1%, and the number of moldings up to mold contamination was 400.
It was as low as 0 times.

(Comparative Example 2) Amorphous germanium dioxide was used as a polycondensation catalyst, and the amount of talc added was 30 pp.
m, and PET was removed in the same manner as in Example 1 except that fines and the like were not removed by a sieving step after solid-phase polymerization.
I got As shown in Table 1, the molded article had a Tc of 122.8.
° C, Tc1 is 133.5 ° C, and the haze of the molded product is 36.2%.
Met. In addition, the density of the plug portion was as high as 1.393 g / cm ³ , which was excessively crystallized. Further, deformation of the bottle plug portion and leakage of the contents after the content filling test were examined. Although there was no deformation, leakage of the contents was observed.
19.2% bottle body haze after 5,000 consecutive moldings
It was not possible to determine the number of moldings until the mold was stained because the transparency of the part was very poor.

[0118]

[Table 1]

[0119]

According to the polyester of the present invention, there is no change in crystallinity or size after crystallization of the plug portion, and it is possible to carry out the crystallization treatment of the plug portion of stable quality in a short time. In addition, a hollow molded article having excellent transparency and heat-resistant dimensional stability can be obtained.Also, there is little mold contamination in bottle molding and the like, excellent long-term continuous moldability, and transparency of a large number of hollow molded articles can be obtained. It can be easily molded in an excellent condition.

[Brief description of the drawings]

[1] absorbance of 515 cm ^-1 to the absorbance of germanium dioxide in the 550cm ^-1 (A550cm ^-1) (A
515 cm ^-1 ) ratio D (A 515 cm ^-1 / A 550 cm)
^-1 ) Infrared absorption spectrum for obtaining

FIG. 2 is a schematic view of an apparatus used in the method for producing a polyester of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Raw material chip supply port 2 Overflow discharge port 3 Polyester chip and treated water discharge port 4 Drainer 5 Fine powder removal device 6 Pipe 7 Treated water inlet 8 Adsorption tower 9 Ion exchange water inlet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) (C08L 67/02 (C08L 67/02 77:00) 77:00) (C08L 67/02 (C08L 67 / 02 59:00) 59:00) F term (reference) 4F071 AA46 AA82 AA83 AA87 AA89 AF30 AF54 AH05 BB07 BB09 BC01 BC04 4J002 CB002 CF061 CF072 CL002 GG01 4J029 AA03 AB01 AC01 AC02 AD08 AD10 AE01 AE03 BA02 BA03 BA04 BA05 HA01 HB01 HB02 HB03 JF22 JF32 JF36 JF47 KC02 KE02 KE05 KE15 LB05

Claims (14)

[Claims] 1. A polyester having a main repeating unit composed of ethylene terephthalate, which is measured by a differential scanning calorimeter (DSC) when the temperature of a molded product obtained from the polyester is increased after heat treatment. Crystallization temperature (T
c) the polyester in the range of 120C to 150C. 2. The crystallization temperature (Tc1) of the molded body at the time of temperature rise measured by a differential scanning calorimeter (DSC) is 15
The temperature range is from 0 ° C to 175 ° C.
Polyester according to the above. 3. The polyester according to claim 1, wherein the molded article has a haze of 15% or less. 4. A polyester comprising a polyester chip and a polyester having the same composition as the polyester chip.
The polyester according to claim 1, 2 or 3, wherein the polyester is a mixture of the polyester with the same. 5. The polyester according to claim 1, wherein the amount of the cyclic trimer increased by melting at a temperature of 290 ° C. for 60 minutes is 0.30% by weight or less. 6. A polyolefin resin, a polyamide resin,
At least one resin selected from the group consisting of polyacetal resins and polybutylene terephthalate resins;
The polyester according to any one of claims 1, 2, 3, 4, and 5, wherein the polyester is blended with ppb to 1000 ppm. 7. The content of the copolymerized diethylene glycol is one of the glycol components constituting the polyester.
The compound according to claim 1, wherein the amount is 0 to 5.0 mol%.
Polyester according to 2, 3, 4, 5 or 6. 8. The polyester chip has a density of 1.37.
g / cm ³ or more,
Polyester according to 3, 4, 5, 6 or 7. 9. An acetaldehyde content of 10 ppm
Claims 1, 2, 3, 4,
The polyester according to 5, 6, 7 or 8. 10. The method according to claim 1, wherein the content of the cyclic trimer is 0.50% by weight or less.
The polyester according to 5, 6, 7, 8 or 9. 11. The polyester has a sodium content, a magnesium content, a silicon content and a calcium content in the cooling water in the chipping step after the melt polycondensation, respectively, being N, M, S and C. In the case, the following (1)
4. A chip formed by using cooling water satisfying at least one of (4) to (4).
The polyester according to 2, 3, 4, 5, 6, 7, 8, 9 or 10. N ≦ 1.0 (ppm) (1) M ≦ 0.5 (ppm) (2) S ≦ 2.0 (ppm) (3) C ≦ 1.0 (ppm) (4) 12. The method of claim 1, 2, 3, 4, 5, 6, 7,
A hollow molded article obtained by molding the polyester described in 8, 9, 10 or 11. 13. The method of claim 1, 2, 3, 4, 5, 6, 7,
A sheet-like material obtained by molding the polyester according to 8, 9, 10 or 11. 14. A stretched film obtained by stretching the sheet-like material according to claim 13 in at least one direction.