JP2007138158A - Polyester composition, polyester molded article made thereof and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester composition effective for efficiently producing a blow-molded article having excellent transparency, pressure resistance or high-temperature dimensional stability, especially a blow-molded article having excellent heat resistance by a high-speed molding process while suppressing the formation of aldehydes such as acetaldehyde and cyclic ester oligomers in molding, by using a polyester composition having a water-content falling within a specific range and composed of a polyester having low water-content and a polyester having high water-content and having an intrinsic viscosity difference falling within a specific range. <P>SOLUTION: The polyester composition contains a polyester A having a water-content of ≤100 ppm and a polyester B having a water-content of 0.05-0.6 wt.% as main components. The composition of the polyester A is essentially same as that of the polyester B, the intrinsic viscosity difference of the polyesters is 0.05-0.40 dL/g and the water-content of the polyester composition is 10-700 ppm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a polyester suitably used as a raw material for a hollow molded body such as a bottle for beverages, a molded body such as a sheet, a film, or a coating coated on a substrate such as paper or film. The present invention relates to a composition and its use. In particular, a polyester composition that provides a molded product or a coating having excellent transparency and little variation in transparency, and the transparency and flavor retention comprising these, are suppressed in the formation of aldehydes such as acetaldehyde and cyclic ester oligomers during molding. The present invention relates to a polyester molded article having excellent properties.

  Polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) are excellent in both mechanical properties and chemical properties, and thus have high industrial value, such as fibers, films, sheets, and bottles. Widely used as such.

  As a material for containers such as seasonings, oils, beverages, cosmetics, and detergents, various resins are employed depending on the type of filling contents and the purpose of use.

  Of these, polyester is excellent in mechanical strength, heat resistance, transparency and gas barrier properties, and is particularly suitable as a material for molded articles such as beverage filling containers such as juices, soft drinks and carbonated drinks. is there.

  For example, such polyester is supplied to a molding machine such as an injection molding machine to form a preform for a hollow molded body, and the preform is inserted into a mold having a predetermined shape and stretched blow molded to cool it. It is made into a hollow molded container for beverages, or it is molded into a heat-resistant or pressure-resistant hollow molded container by heat-treating the preform plug part (crystallization of the plug part) and then stretching blow molding and heat-treating the body part (heat set). It is common. However, when the crystallization of the plug portion is insufficient or the variation in crystallinity is large, the sealing performance with the cap is deteriorated, and the contents may leak.

  In order to solve such problems, in the case of beverages that require hot filling, such as fruit juice beverages, oolong tea, and mineral water, the mouth portion of the preform or molded bottle is heat-treated and crystallized. A method (for example, see Patent Document 1) is common. Such a method, that is, a method of improving the heat resistance by heat-treating the plug portion and the shoulder portion, the time and temperature for the crystallization treatment greatly affect the productivity, and can be processed at a low temperature in a short time. It is preferable that the conversion rate is PET. On the other hand, the body portion is required to be transparent even if heat treatment is performed at the time of molding so as not to deteriorate the color tone of the contents of the bottle, and the mouthpiece portion and the body portion must have contradictory characteristics.

  In the case of PET, in order to solve such a problem of mold contamination, conventionally, a method of reducing the cyclic trimer, which is the main component of the deposit on the mold surface, by solid-phase polymerization in advance (for example, In this method, the cyclic trimer is regenerated when it is remelted and preformed, and its effect is insufficient. Also disclosed are a method of deactivating a catalyst by contact treatment with water (for example, see Patent Document 2) and a PET having a catalyst deactivated by water treatment (for example, see Patent Document 3). Yes. However, even with the above method, the amount of cyclic oligomer produced at the time of melting is reduced and the mold contamination is reduced temporarily. However, the crystallization speed is unstable, the plug portion dimension accuracy is poor, and the shape is whitened. There is a problem that defects such as flow patterns and bubbles are likely to occur, and only bottles with poor transparency can be obtained, and a solution is awaited.

  Various proposals have been made to solve the problems of improvement and stabilization of the crystallization rate. For example, there is a method of adding an inorganic nucleating agent such as kaolin and talc to polyethylene terephthalate (see, for example, Patent Document 4), but these methods are problematic in practical use with the generation of foreign matter and cloudiness. Further, a method of adding a treated polyester obtained by pulverizing a polyester molded body obtained by melt molding from the polyester to the raw material polyester (see, for example, Patent Documents 5 and 6), hydrolyzing the polyester and the intrinsic viscosity A particle mixture (for example, Patent Document 7) with polyester reduced by 0.01 to 0.25 dl / g has been proposed, but these are extra steps such as a melt molding pulverization step and a hydrolysis step at 100 ° C. or higher. In addition, there is a risk that foreign substances other than polyester are mixed in such a post-process, and this is not a preferable method in terms of economy and quality. Also, a method for producing a container using a composition comprising two kinds of polyesters having different ranges of intrinsic viscosities having a specific range of temperature-rise crystallization temperature and temperature-fall crystallization temperature (see, for example, Patent Document 8) However, it is difficult to produce bottles with excellent transparency and heat resistance by high-speed molding, and there is a problem in recyclability, such as adversely affecting transparency when re-molding used containers.

  In addition, a PET modification method by bringing a PET chip into contact with a polyethylene member under flow conditions, a polyester resin composition in which 0.1 to 45 ppb of polyethylene is blended with a polyester resin (see, for example, Patent Document 9), etc. Although proposed, such a method and a polyester resin composition have an appropriate and stable crystallization speed, are free from defects such as whitened flow patterns and bubbles, and have excellent transparency. It has been found that it is very difficult to obtain a molded article having excellent heat-resistant dimensional stability.

  Further, PET contains acetaldehyde (hereinafter sometimes abbreviated as AA) as a by-product during melt polycondensation. In addition, PET produced acetaldehyde by thermal decomposition when thermoforming a molded body such as a hollow molded body, and the acetaldehyde content in the material of the obtained molded body was increased, and the hollow molded body was filled. Affects the flavor and odor of beverages.

  In recent years, polyester containers such as polyethylene terephthalate have come to be used as containers for low flavor beverages such as mineral water and oolong tea. In the case of such beverages, these beverages are generally heat-filled or sterilized by heating after filling, but it is becoming increasingly important to reduce the acetaldehyde content of the beverage container. In addition, for beverage metal cans, for the purposes of process simplification, hygiene, pollution prevention, etc., cans are made using a metal plate whose inner surface is coated with a polyester film whose main repeating unit is ethylene terephthalate. The method to do has come to be adopted. In this case as well, the contents are filled and sterilized by heating at a high temperature. At this time, it is found that the use of a film having a sufficiently low acetaldehyde content is an essential requirement for improving the flavor and odor of the contents. I came.

  For these reasons, various measures have been taken to reduce the acetaldehyde content in the polyester. As these measures, for example, a method of reducing AA content by solid-phase polymerization of melt-polycondensed polyester, a method of reducing AA generation during molding using a copolymer polyester having a lower melting point, polyester resin A method using a polyester composition in which 0.05 parts by weight or more and less than 1 part by weight of a metaxylylene group-containing polyamide resin is added to 100 parts by weight (see, for example, Patent Document 10), and the molding temperature during thermoforming is made possible. A method for reducing the shear stress and a method for reducing the shear stress during thermoforming as much as possible have been proposed. However, even in a molded body using polyester obtained by these methods, it cannot be said that oligomers and acetaldehyde can be reduced to a problem-free level, and the problem remains unsolved.

Moreover, in order to reduce the acetaldehyde content of a polyester molding, the method (for example, refer patent document 11, 12) of melt-molding the polyester containing the moisture content of about 60-500 ppm is disclosed. However, even if such a technique is used, it has been found that it is difficult to further reduce the acetaldehyde content while maintaining the transparency of the molded body by molding at a lower temperature, and a solution is awaited. Yes.
JP 55-89330 A Japanese Patent Laid-Open No. 3-47830 Japanese Patent Laid-Open No. 3-72524 JP-A-56-2342 Japanese Patent Laid-Open No. 5-105807 JP-A-6-116392 JP-A-6-116485 Japanese Patent Laid-Open No. 10-287799 JP-A-9-151308 Japanese Examined Patent Publication No. 6-6661 JP-A-7-205257 JP 2004-359837 A

  The present invention is intended to solve the above-mentioned problems of the prior art, and a specific range of moisture, comprising a low moisture content polyester and a high moisture content polyester, in which the difference in intrinsic viscosity is in a specific range. The production of aldehydes such as acetaldehyde and the formation of cyclic ester oligomers during molding is suppressed by using a polyester composition containing a percentage, and a hollow molded body excellent in transparency, pressure resistance or heat-resistant dimensional stability, particularly heat resistance An object of the present invention is to provide a polyester composition capable of efficiently producing a hollow molded article having excellent properties by high-speed molding and a polyester molded article comprising the same.

  The inventors of the present invention have arrived at the present invention as a result of intensive studies to achieve the above object. That is, the polyester composition of the present invention is a polyester composition containing, as main components, polyester A having a moisture content of 100 ppm or less and polyester B having a moisture content of 0.05 to 0.6% by weight. Is a composition having substantially the same composition as that of polyester B, the difference between these intrinsic viscosities is in the range of 0.05 to 0.40 deciliter / gram, and the moisture content is 10 to 700 ppm. It is a thing.

  Here, “substantially the same” means that the acid component and the glycol component in each polyester are preferably 95 mol% or more, more preferably 97 mol% or more, particularly 98 mol% or more. Is preferred.

  The moisture content of polyester A constituting the polyester composition of the present invention is preferably 90 ppm or less, more preferably 70 ppm or less, particularly preferably 60 ppm or less, and most preferably 50 ppm or less. When the moisture content of polyester A exceeds 100 ppm, depending on the blending amount of polyester B and the moisture content, a significant molecular weight decrease occurs at the time of melting, so the transparency and mechanical properties of the molded product are greatly reduced. Become. The lower limit of the moisture content of the polyester A is 1 ppm because of the relationship between the capacity of the drying equipment and the equipment cost, the economics of the drying process, and the like.

  Further, the moisture content of polyester B is preferably 0.07 to 0.55% by weight, more preferably 0.10 to 0.50% by weight, particularly preferably 0.15 to 0.48% by weight, and most preferably 0.20 to 0.45% by weight. When the moisture content of the polyester B is less than 0.05% by weight, the effect of improving fluidity is not exhibited, and the obtained molded article has poor transparency and appearance, and these problems are particularly noticeable during low temperature molding. When the moisture content of polyester B exceeds 0.6% by weight, depending on the blending amount of polyester B and the value of moisture content, the molecular weight of the molded product from the polyester composition is lowered due to hydrolysis that occurs during melting, and the molded product. Decrease in transparency and mechanical properties are undesirably caused.

  The difference in intrinsic viscosity of the polyester constituting the polyester composition of the present invention is preferably 0.06 to 0.37 deciliter / gram, more preferably 0.07 to 0.33 deciliter / gram, particularly preferably 0.10. ~ 0.30 deciliter / gram. When the intrinsic viscosity difference is less than 0.05 deciliter / gram, the transparency of the molded product obtained by molding at a low temperature of 290 ° C. or lower is deteriorated, and on the other hand, the transparency of the molded product is improved. Under molding temperature conditions, the content of aldehydes such as acetaldehyde cannot be reduced, and flavor retention cannot be improved. On the other hand, when the intrinsic viscosity difference exceeds 0.40 deciliter / gram, thickness irregularities, whitened flow patterns and the like are generated in the obtained molded product, resulting in a problem of poor transparency. Here, when the polyester composition of the present invention comprises two or more kinds of polyesters, the difference in intrinsic viscosity is the difference in intrinsic viscosity between the maximum polyester and the minimum polyester with respect to the intrinsic viscosity.

  The moisture content of the polyester composition of the present invention is preferably 13 to 600 ppm, more preferably 15 to 500 ppm, particularly preferably 18 to 400 ppm, and most preferably 20 to 300 ppm. When it exceeds 700 ppm, the intrinsic viscosity of the obtained molded product is too low, and the transparency and mechanical strength are deteriorated. If it is less than 10 ppm, the fluidity improving effect is not exhibited, the transparency and appearance of the obtained molded article are poor, and the production of aldehydes and cyclic ester oligomers cannot be suppressed.

The polyester composition of the present invention is a polyester composition containing, as a main component, a polyester having ethylene terephthalate as a main repeating unit, and the polyesters are the following polyester C and polyester D. A polyester composition characterized in that the difference in viscosity is in the range of 0.05 to 0.40 deciliter / gram and the moisture content is 10 to 700 ppm.
Polyester C: Intrinsic viscosity is 0.60 to 0.80 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 100 ppm or less, crystallization temperature measured by DSC is 140 to 180 ° C., and temperature is lowered Polyester having a crystallization temperature of 160 to 200 ° C.
Polyester D: Intrinsic viscosity is 0.70 to 1.00 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 0.05 to 0.6% by weight, and crystallization temperature when measured by DSC is 140. Polyester having a crystallization temperature of 160 to 200 ° C. at a temperature of ˜180 ° C.

The polyester composition of the present invention is a polyester composition containing, as a main component, a polyester having ethylene terephthalate as a main repeating unit, and the polyesters are the following polyester E and polyester F. A polyester composition characterized in that the difference in viscosity is in the range of 0.05 to 0.40 deciliter / gram and the moisture content is 10 to 700 ppm.
Polyester E: Intrinsic viscosity is 0.60 to 0.80 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 0.05 to 0.6% by weight, and crystallization temperature at the time of temperature rise measured by DSC is 140. Polyester having a crystallization temperature of 160 to 200 ° C. at a temperature of ˜180 ° C.
Polyester F: Intrinsic viscosity is 0.70 to 1.00 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 100 ppm or less, crystallization temperature when measured by DSC is 140 to 180 ° C., temperature is decreased Polyester having a crystallization temperature of 160 to 200 ° C.

  Here, DSC measurement of polyesters such as the above-mentioned polyester A is a molded plate injection-molded at 290 ° C. by the following method using individual polyester samples whose moisture content is 100 ppm or less, preferably 50 ppm or less by drying. (2 mm thickness) is carried out by the following method.

  That is, the polyester composition of the present invention is a polyester composition comprising a low moisture content polyester and a high moisture content polyester, or a low moisture content, low intrinsic viscosity polyester having a specific characteristic and a high moisture content, a high intrinsic viscosity. A polyester composition comprising a polyester having a high moisture content, low intrinsic viscosity, and a polyester composition comprising a polyester having a low moisture content and a high intrinsic viscosity, and a polyester having a lower intrinsic viscosity. Due to the effect of improving the fluidity at the time of melting in the extruder and the effect of moisture in the high moisture content polyester, molding at a lower temperature is possible, and the resulting molded product has very high transparency and appearance In addition, the content of aldehydes such as acetaldehyde and the content of cyclic ester oligomers can be reduced. It made. At the same time, the orientation during heating and stretching is also improved, so that it is possible to give stretched molded articles with excellent mechanical properties such as elastic modulus and tensile strength, as well as excellent heat fixability, especially heat resistance or pressure resistance. It can be beneficially used as a stretched hollow container excellent in. In particular, in the present invention, the viscosity of the polyester melt is lowered within a proper range at the time of melting due to moisture present in the polyester B, polyester D, or polyester E, whereby the polyester A dried to a moisture content of 100 ppm or less. Since the heat generation in the molding machine is suppressed as compared with the case of molding using only polyester C or polyester F, the temperature of the melt is lowered, the transparency and appearance of the molded body are greatly improved, and aldehydes And the formation of cyclic s oligomers.

  Polyester C, polyester D, polyester E and polyester F according to the present invention can be obtained by appropriately adjusting the production method described below. In particular, the crystallization temperature at the time of temperature reduction and the crystallization temperature at the time of temperature rise of these polyesters are the water quality of the cooling water at the time of chip formation of the melt polycondensation polymer, the fine content of each polyester or polyester composition and its properties or It is possible to control the amount of resin such as polyolefin resin in combination as appropriate.

The moisture content of polyester A, polyester C or polyester F can be adjusted by heat drying under reduced pressure or sufficient heat drying under an inert gas.
The moisture content of polyester B, polyester D or polyester E is, for example, a method of immersing these chips in water to dehydrate and remove surface adhering water, a method of leaving in a high humidity atmosphere or air for a long time, The moisture content can be adjusted within the range of the moisture content by various methods such as a method of supplying moisture corresponding to the rate to the polyester before molding or a method of appropriately adjusting the drying conditions.

  Here, the polyesters having different intrinsic viscosities used in the present invention are polyesters produced so that the difference in intrinsic viscosities falls within the scope of the present invention in the melt polycondensation reaction step or the subsequent solid phase polymerization reaction step. Or a polyester obtained by subjecting these to contact with water under a condition in which the intrinsic viscosity does not decrease.

  As other production methods for obtaining polyesters having different intrinsic viscosities, there are a method of hydrolyzing polyester by heat treatment with water at a high temperature, a method of melt treatment with an extruder, and the like. However, since the method by hydrolysis is carried out in a solid state, it is very difficult to control the degree of IV reduction, it is difficult to obtain polyester particles having a narrow IV fluctuation range, and particles after hydrolysis treatment Is likely to generate fine powder due to impact during transportation, etc., so that there is a problem that the fluctuation of the transparency and crystallization speed of the molded body when these are used becomes very large. The fluctuation is a big problem. In addition, the method using the melt treatment has problems such as an influence on flavor retention and coloring due to an increase in aldehydes such as acetaldehyde during the treatment. Therefore, the polyester according to the present invention does not include polyester hydrolyzed by a method such as heat treatment under pressure with water or the like, or polyester melt-treated to reduce IV.

  In this case, the aldehyde content is preferably 50 ppm or less.

  In this case, the cyclic ester oligomer content is preferably 70% or less of the cyclic ester oligomer content of the melt polycondensed polyester prepolymer.

  In this case, it is preferable that the cyclic ester oligomer increase amount is 0.40% by weight or less when melted at a temperature of 290 ° C. for 60 minutes.

  In this case, it is a polyester molded body obtained by melt-molding the polyester composition, and the polyester molded body is formed by stretching a hollow molded body, a sheet-shaped material, or this sheet-shaped material in at least one direction. A polyester molded body characterized by being a stretched film.

  Moreover, in this case, it can be a coating characterized by melting and extruding the polyester composition on a substrate.

  Furthermore, the polyester composition according to claim 2 or the polyester composition according to claim 3 has a melt resin temperature in the molding machine of 240 to 305 ° C. and a melt residence time in the molding machine of 5 to 500. The above purpose can be achieved by kneading and molding under the conditions of seconds.

  Since the present invention has improved flow characteristics, it can be molded at a low temperature, has excellent transparency, has a small amount of aldehydes and cyclic ester oligomers during molding, and has a molded body. Provides a polyester composition that provides a molded article or coating excellent in mechanical properties such as pressure resistance. In addition, since the polyester composition of the present invention has improved flow characteristics, there is little distortion during molding, and a molded article having excellent heat-resistant dimensional stability, particularly a hollow molded article, can be efficiently produced by high-speed molding, and The present invention provides a polyester composition excellent in long-term continuous moldability, which gives a molded article having very good pressure resistance and heat-resistant dimensional stability, and which does not stain the mold, and a method for producing the same. The polyester composition of the present invention can meet high quality requirements in the field of containers, sheets and the like.

Hereinafter, embodiments of the polyester composition of the present invention will be specifically described.
The polyester according to the present invention is a thermoplastic polyester mainly obtained from an aromatic dicarboxylic acid component and a glycol component, preferably a polyester containing 70 mol% or more of an aromatic dicarboxylic acid unit of the acid component, more preferably A polyester containing 85 mol% or more of an aromatic dicarboxylic acid unit, particularly preferably a polyester containing 95 mol% or more of an aromatic dicarboxylic acid unit of an acid component.

  The aromatic dicarboxylic acid component constituting the polyester according to the present invention includes aromatic dicarboxylic acids such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid, and the like. And functional derivatives.

  Examples of the glycol component constituting the polyester according to the present invention include aliphatic glycols such as ethylene glycol, 1,3-trimethylene glycol and tetramethylene glycol, and alicyclic glycols such as cyclohexanedimethanol.

  Examples of the dicarboxylic acid used as a copolymerization component when the polyester is a copolymer include isophthalic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid, and 4,4′-diphenyl ether dicarboxylic acid. , Aromatic dicarboxylic acids such as 4,4′-diphenyl ketone dicarboxylic acid and functional derivatives thereof, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, adipic acid, sebacic acid, succinic acid, Examples thereof include aliphatic dicarboxylic acids such as glutaric acid and dimer acid and functional derivatives thereof, and alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid and cyclohexanedicarboxylic acid, and functional derivatives thereof.

  The glycol as a copolymerization component used when the polyester is a copolymer is diethylene glycol, 1,3-trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene. Glycols, 2-ethyl-2-butyl-1,3-propanediol, aliphatic glycols such as neopentyl glycol, dimer glycol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol 1,4-cyclohexane dimethylol, 2,5-norbornane dimethylol and the like alicyclic glycols, xylylene glycol, 4,4′-dihydroxybiphenyl, 2,2-bis (4′-β-hydroxyeth Cyclophenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfonic acid, aromatic glycols such as alkylene oxide adducts of bisphenol A, polyalkylene glycols such as polyethylene glycol and polybutylene glycol Etc.

  Furthermore, examples of the polyfunctional compound as a copolymer component used when the polyester is a copolymer include trimellitic acid, pyromellitic acid, and the like as an acid component, and glycerin and pentane as glycol components. Mention may be made of erythritol. The amount of copolymerization component used should be such that the polyester remains substantially linear. Monofunctional compounds such as benzoic acid and naphthoic acid may be copolymerized.

A preferred example of the polyester according to the present invention is a polyester whose main structural unit is composed of ethylene terephthalate, more preferably 70 mol% or more of ethylene terephthalate units, and isophthalic acid, 1,4-cyclohexanedi, as a copolymerization component. A copolyester containing methanol or the like, particularly preferably a polyester containing 95 mol% or more of ethylene terephthalate units.
Examples of these polyesters include polyethylene terephthalate (hereinafter abbreviated as PET), poly (ethylene terephthalate-ethylene isophthalate) copolymer, poly (ethylene terephthalate-1,4-cyclohexanedimethylene terephthalate) copolymer, poly ( Examples thereof include an ethylene terephthalate-dioxyethylene terephthalate) copolymer, a poly (ethylene terephthalate-1,3-propylene terephthalate) copolymer, and a poly (ethylene terephthalate-ethylene cyclohexylene dicarboxylate) copolymer.

In addition, another preferable example of the polyester according to the present invention is a polyester in which the main structural unit is composed of 1,3-propylene terephthalate, and more preferably a polyester including 70 mol% or more of 1,3-propylene terephthalate units. Particularly preferred are polyesters containing 95 mol% or more of 1,3-propylene terephthalate units.
Examples of these polyesters include polypropylene terephthalate (PTT), poly (1,3-propylene terephthalate-1,3-propylene isophthalate) copolymer, poly (1,3-propylene terephthalate-1,4-cyclohexanedimethylene). Terephthalate) copolymer and the like.

Furthermore, other preferable examples of the polyester according to the present invention are polyesters in which the main structural unit is composed of butylene terephthalate, more preferably a copolyester containing 70 mol% or more of butylene terephthalate units, and particularly preferable. Is a polyester containing 95 mol% or more of butylene terephthalate units.
Examples of these polyesters include polybutylene terephthalate (PBT), poly (butylene terephthalate-butylene isophthalate) copolymer, poly (butylene terephthalate-1,4-cyclohexanedimethylene terephthalate) copolymer, poly (butylene terephthalate- 1,3-propylene terephthalate) copolymer, poly (butylene terephthalate-butylene cyclohexylene dicarboxylate) copolymer, and the like.

Another preferred example of the polyester according to the present invention is a thermoplastic polyester in which the main structural unit is composed of ethylene-2,6-naphthalate, and more preferably 70 mol% or more of ethylene-2,6-naphthalate unit. The thermoplastic polyester is particularly preferably a thermoplastic polyester containing 90 mol% or more of ethylene-2,6-naphthalate units.
Examples of these thermoplastic polyesters include polyethylene-2,6-naphthalate (PEN), poly (ethylene-2,6-naphthalate-ethylene terephthalate) copolymer, poly (ethylene-2,6-naphthalate-ethylene isophthalate). ) Copolymer, poly (ethylene-2,6-naphthalate-dioxyethylene-2,6-naphthalate) copolymer, and the like.

  The polyester according to the present invention can basically be produced by a conventionally known melt polycondensation method or melt polycondensation method-solid phase polymerization method. The melt polycondensation reaction may be performed in one stage or may be performed in multiple stages. These may be comprised from a batch-type reaction apparatus, and may be comprised from the continuous-type reaction apparatus. The melt polycondensation step and the solid phase polymerization step may be operated continuously or may be operated separately. Hereinafter, an example of a preferable continuous production method for the polyester composition of the present invention will be described using polyethylene terephthalate (PET) as an example, but the present invention is not limited thereto. That is, a direct esterification method in which terephthalic acid, ethylene glycol, and if necessary, other copolymerization components are directly reacted and esterified while distilling off water, followed by polycondensation under reduced pressure in the presence of a polycondensation catalyst, Or transesterification by reacting dimethyl terephthalate with ethylene glycol and other copolymerization components if necessary, and transesterifying while distilling off methyl alcohol, followed by polycondensation under reduced pressure in the presence of a polycondensation catalyst Manufactured by. Then, when the intrinsic viscosity is increased or the low acetaldehyde content or the low cyclic trimer content is used, such as a heat-resistant container for low flavor beverages or a film for inner surfaces of metal cans for beverages. The resulting melt polycondensed polyester is subsequently subjected to solid state polymerization.

  First, when a low polymer is produced by an esterification reaction, 1.02 to 2.0 mol, preferably 1.03 to 1.4 mol of ethylene glycol is added to 1 mol of terephthalic acid or an ester derivative thereof. The contained slurry is prepared and continuously supplied to the esterification reaction step.

In the esterification reaction, water or alcohol produced by the reaction is removed out of the system by a rectification column under conditions where ethylene glycol is refluxed using a multistage apparatus in which at least two esterification reactors are connected in series. While implementing. The temperature of the first stage esterification reaction is 240 to 270 ° C., preferably 245 to 265 ° C., and the pressure is 0.2 to 3 kg / cm ² G, preferably 0.5 to ² kg / cm ² G. The temperature of the esterification reaction in the final stage is usually 250 to 280 ° C, preferably 255 to 275 ° C, and the pressure is usually 0 to 1.5 kg / cm ² G, preferably 0 to 1.3 kg / cm ² G. . When carried out in three or more stages, the reaction conditions for the esterification reaction in the intermediate stage are conditions between the reaction conditions for the first stage and the reaction conditions for the final stage. The increase in the reaction rate of these esterification reactions is preferably distributed smoothly at each stage. Ultimately, it is desirable that the esterification reaction rate reaches 90% or more, preferably 93% or more. By these esterification reactions, low-order condensates having a molecular weight of about 500 to 5,000 are obtained.

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, quaternary ammonium hydroxides such as tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, trimethylbenzylammonium hydroxide, and lithium carbonate When a small amount of a basic compound such as sodium carbonate, potassium carbonate or sodium acetate is added, the proportion of dioxyethylene terephthalate component units in the main chain of polyethylene terephthalate is relatively low (5% relative to all diol components). Mol% or less).

  Next, in the case of producing a low polymer by transesterification, 1.1 to 2.0 mol, preferably 1.2 to 1.5 mol of ethylene glycol was contained with respect to 1 mol of dimethyl terephthalate. The solution is prepared and continuously fed to the transesterification step.

  The transesterification reaction is carried out while removing methanol generated by the reaction outside the system using a rectification column under the condition that ethylene glycol is distilled back using an apparatus in which 1 to 2 transesterification reactors are connected in series. To do. The temperature of the first stage transesterification is 180 to 250 ° C, preferably 200 to 240 ° C. The temperature of the transesterification reaction in the final stage is usually 230 to 270 ° C., preferably 240 to 265 ° C., and as the transesterification catalyst, fatty acid salts such as Zn, Cd, Mg, Mn, Co, Ca, Ba, carbonates Alternatively, Pb, Zn, Sb, Ge oxide or the like is used. A low-order condensate having a molecular weight of about 200 to 500 is obtained by these transesterification reactions.

  Dimethyl terephthalate, terephthalic acid or ethylene glycol, which is the starting material, includes virgin dimethyl terephthalate derived from para-xylene, ethylene glycol derived from terephthalic acid or ethylene, as well as methanol decomposition from used PET bottles. A recovered raw material such as dimethyl terephthalate, terephthalic acid, bishydroxyethyl terephthalate or ethylene glycol recovered by a chemical recycling method such as decomposition of ethylene glycol or ethylene glycol can also be used as at least part of the starting material. Needless to say, the quality of the recovered raw material must be refined to a purity and quality suitable for the intended use.

  Subsequently, the obtained low-order condensate is supplied to a multistage liquid phase condensation polymerization process. The polycondensation reaction conditions are as follows: the first stage polycondensation reaction temperature is 250 to 290 ° C., preferably 260 to 280 ° C., and the pressure is 500 to 20 Torr, preferably 200 to 30 Torr. The temperature 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 carried out in three or more stages, the reaction conditions for the intermediate stage polycondensation reaction are conditions between the reaction conditions for the first stage and the reaction conditions for the last stage. The degree of increase in intrinsic viscosity achieved in each of these polycondensation reaction steps is preferably distributed smoothly. A single-stage polycondensation apparatus may be used for the polycondensation reaction.

  The polycondensation reaction is performed using a polycondensation catalyst. As the polycondensation catalyst, at least one compound selected from Ge, Sb, Ti, or Al compounds is preferably used. These compounds are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries and the like.

  Examples of the Ge compound include amorphous germanium dioxide, crystalline germanium dioxide powder or ethylene glycol slurry, a solution obtained by heating and dissolving crystalline germanium dioxide in water, or a solution obtained by adding ethylene glycol to this and heat treatment. In particular, in order to obtain the polyester used in the present invention, it is preferable to use a solution in which germanium dioxide is dissolved by heating in water, or a solution in which ethylene glycol is added and heated. In addition, compounds such as germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, and germanium phosphite can also be used. These polycondensation catalysts can be added during the esterification step. When a Ge compound is used, the amount used is preferably 10 to 150 ppm, more preferably 13 to 100 ppm, and still more preferably 15 to 70 ppm as the residual amount of Ge in the polyester.

  Examples of Ti compounds include tetraethyl titanates, tetraisopropyl titanates, tetra-n-propyl titanates, tetraalkyl titanates such as tetra-n-butyl titanates and partial hydrolysates thereof, titanium acetate, titanyl oxalate, titanyl ammonium oxalate, titanyl oxalate Sodium, titanyl oxalate, titanyl calcium oxalate, titanyl succinate, titanyl succinate, titanium trimellitic acid, titanium sulfate, titanium chloride, titanium halide hydrolyzate, titanium oxalate, titanium fluoride, titanium hexafluoride Titanium with potassium acid, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, titanium acetylacetonate, hydroxy polyvalent carboxylic acid or nitrogen-containing polyvalent carboxylic acid A phosphorus compound is reacted with a complex compound, a composite oxide composed of titanium and silicon or zirconium, a reaction product of titanium alkoxide and a phosphorus compound, or a reaction product of titanium alkoxide and an aromatic polycarboxylic acid or its anhydride. The reaction product obtained by the above. The Ti compound is added so that the residual amount of Ti in the produced polymer is 0.1 to 50 ppm, more preferably 0.5 to 30 ppm, and still more preferably 1 to 10 ppm.

  Examples of the Sb compound include antimony trioxide, antimony acetate, antimony tartrate, antimony potassium tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, and triphenylantimony. The Sb compound is added so that the amount of Sb remaining in the produced polymer is preferably 50 to 300 ppm, more preferably 80 to 250 ppm, and still more preferably 100 to 200 ppm.

  Al compounds include aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate, aluminum phosphonate and other inorganic acid salts, aluminum n-propoxide, aluminum iso-propoxide Aluminum alkoxides such as aluminum n-butoxide and aluminum t-butoxide, aluminum chelate compounds such as aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethylacetoacetate diiso-propoxide, trimethylaluminum, triethylaluminum, etc. Organic aluminum compounds and partial hydrolysates thereof, aluminum oxide, etc. It is. Of these, aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred. The Al compound is added so that the Al residual amount in the produced polymer is in the range of 5 to 200 ppm, more preferably 10 to 100 ppm, and still more preferably 15 to 50 ppm.

  In the production of polyester A and polyester B according to the present invention, an alkali metal compound or an alkaline earth metal compound may be used in combination as necessary. The alkali metal or alkaline earth metal is preferably at least one selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba, and the use of an alkali metal or a compound thereof is preferable. More preferred. When using an alkali metal or a compound thereof, use of Li, Na, K is particularly preferable. Examples of the alkali metal and alkaline earth metal compounds include saturated aliphatic carboxylates such as formic acid, acetic acid, propionic acid, butyric acid, and succinic acid, and unsaturated aliphatic carboxylates such as acrylic acid and methacrylic acid. , Aromatic carboxylates such as benzoic acid, halogen-containing carboxylates such as trichloroacetic acid, hydroxycarboxylates such as lactic acid, citric acid and salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, phosphorus Inorganic acid salts such as acid hydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid and bromic acid, and organic sulfonates such as 1-propanesulfonic acid, 1-pentanesulfonic acid and naphthalenesulfonic acid , Organic sulfates such as lauryl sulfate, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butyl Alkoxides such as alkoxy, chelate compounds and the like acetylacetonate, hydrides, oxides, and hydroxides and the like.

  The 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. 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.

  Furthermore, polyester A and polyester B according to the present invention were selected from the group consisting of silicon, manganese, iron, cobalt, zinc, gallium, strontium, zirconium, niobium, molybdenum, indium, tin, hafnium, thallium, tungsten. A metal compound containing at least one element may be contained. These metal compounds include saturated aliphatic carboxylates such as acetates of these elements, unsaturated aliphatic carboxylates such as acrylates, aromatic carboxylates such as benzoic acid, and halogens such as trichloroacetic acid. Hydroxycarboxylates such as carboxylates and lactates, inorganic acid salts such as carbonates, organic sulfonates such as 1-propanesulfonate, organic sulfates such as lauryl sulfate, oxides, hydroxides, chlorides Products, alkoxides, acetylacetonates, and the like, and 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 elements of these metal compounds per 1 ton of produced polymer is in the range of 0.05 to 3.0 mol. These metal compounds can be added at any stage of the polyester formation reaction step.

  Further, as stabilizers, phosphoric acid, phosphoric acid esters such as polyphosphoric acid and trimethyl phosphate, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, phosphine compounds It is preferable to use at least one phosphorus compound selected from the group consisting of: 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, phosphorous acid trimethyl ester, phosphorous acid triethyl ester, phosphorous acid tributyl ester, methylphosphonic acid, methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid dimethylester, phenylphosphonic acid diethylester, phenylphosphonic acid Diphenyl ester, ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, methyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,5-di isopropyl tert-butyl-4-hydroxybenzylphosphonate, phenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3, 5-di-tert-butyl-4-hydroxybenzylphosphonic acid and the like. These stabilizers can be added during the esterification reaction step from a slurry preparation tank of terephthalic acid and ethylene glycol. The P compound is added so that the residual amount of P in the produced polymer is preferably in the range of 5 to 100 ppm.

  When an Al compound is used as the polycondensation catalyst, it is preferably used in combination with a phosphorus compound, and is preferably used as a solution or slurry in which an aluminum compound and a phosphorus compound are previously mixed in a solvent. In the case of an Al compound, a more preferable phosphorus compound is at least one selected from the group consisting of phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds. It is a phosphorus compound. By using these phosphorus compounds, an effect of improving the catalytic activity is seen, and an effect of improving physical properties such as thermal stability of the polyester is seen. Among these, use of a phosphonic acid compound is preferable because of its great effect of improving physical properties and improving catalytic activity. Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  The melt polycondensation polyester obtained as described above is, for example, a method in which the melt polyester is extruded into water from the die pores after completion of the melt polycondensation and cut in water, or after the melt polycondensation is finished in the air from the die pores. After being extruded into strands, the chips are formed into columns, spheres, squares or plates by a method of forming chips while cooling with cooling water.

Moreover, as the cooling water at the time of chip formation of the melt polycondensed polyester, it is preferable to use cooling water satisfying at least one of the following (1) to (4), and more preferably (1) to (4 It is most preferable to use water that satisfies all of the above.
Na ≦ 1.0 (ppm) (1)
Mg ≦ 1.0 (ppm) (2)
Si ≦ 2.0 (ppm) (3)
Ca ≦ 1.0 (ppm) (4)

  The sodium content (Na) in the cooling water is preferably Na ≦ 0.5 ppm, more preferably Na ≦ 0.1 ppm. The magnesium content (Mg) in the cooling water is preferably Mg ≦ 0.5 ppm, more preferably Mg ≦ 0.1 ppm. Further, the content (Si) of silicon in the cooling water is preferably Si ≦ 0.5 ppm, more preferably Si ≦ 0.3 ppm. Furthermore, the calcium content (Ca) in the cooling water is preferably Ca ≦ 0.5 ppm, and more preferably Ca ≦ 0.1 ppm.

  In order to reduce sodium, magnesium, calcium, and silicon in the cooling water, an apparatus for removing sodium, magnesium, calcium, and silicon is installed in at least one place until the industrial water is sent to the chip cooling process. Also, a filter is installed to remove clay minerals such as silicon dioxide and aluminosilicate particles. 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.

  Next, the previous melt polycondensed polyester chip is preferably pre-crystallized in a continuous crystallization apparatus having two or more stages in an inert gas atmosphere. For example, in the case of PET, the temperature of 100 to 180 ° C. is 1 minute to 5 hours in the first stage precrystallization, and then the temperature of 160 to 210 ° C. is 1 minute to 3 hours in the second stage precrystallization. In the pre-crystallization of the second and higher stages, it is preferable to perform crystallization step by step at a temperature of 180 to 210 ° C. for 1 minute to 3 hours. The crystallinity of the chip after crystallization is preferably in the range of 30 to 65%, preferably 35 to 63%, and more preferably 40 to 60%. The crystallinity can be obtained from the density of the chip.

  Next, solid phase polymerization is carried out in an inert gas atmosphere or under reduced pressure at an optimum temperature for the prepolymer so that the increase in intrinsic viscosity due to solid phase polymerization is 0.10 deciliter / gram or more. For example, in the case of PET, the upper limit of the solid phase polymerization temperature is preferably 215 ° C. or lower, more preferably 210 ° C. or lower, particularly 208 ° C. or lower, and the lower limit is 190 ° C. or higher, preferably 195 ° C. or higher. is there.

  It is preferable to set the chip temperature to about 70 ° C. or less, preferably 60 ° C. or less, more preferably 50 ° C. or less within about 30 minutes, preferably within 20 minutes, more preferably within 10 minutes after completion of the solid phase polymerization.

  The content (aldehyde content) of aldehydes such as acetaldehyde in the polyester composition of the present invention is 50 ppm or less, preferably 30 ppm or less, more preferably 10 ppm or less. When the aldehyde content exceeds 50 ppm, the effect of maintaining the flavor of contents such as a molded article formed from this polyester composition is deteriorated. Further, these lower limits are preferably 0.1 ppb from the viewpoint of production. Here, the aldehydes are acetaldehyde when the polyester is a polyester having ethylene terephthalate as a main constituent unit, and allylaldehyde in the case of a polyester having 1,3-propylene terephthalate as a main constituent unit. It is. In particular, when the polyester composition containing, as a main component, a polyester mainly composed of ethylene terephthalate as the main repeating unit of the present invention is used as a material for containers for low flavor beverages such as mineral water, The acetaldehyde content of the polyester or polyester composition is desirably 10 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, and most preferably 4 ppm or less.

  Further, the intrinsic viscosity of the low intrinsic viscosity polyester (polyester C or polyester E) constituting the polyester composition of the present invention is preferably 0.62 to 0.78 deciliter / gram, more preferably 0.65 to 0.00. 75 deciliter / gram, acetaldehyde content is preferably 8 ppm or less, more preferably 5 ppm or less, crystallization temperature at the time of temperature rise is preferably 145 to 177 ° C., more preferably 150 to 175 ° C., and the crystallization temperature at the time of temperature drop is Preferably it is 162-190 degreeC, More preferably, it is 165-180 degreeC. When the intrinsic viscosity of the low intrinsic viscosity polyester is less than 0.60 deciliter / gram, the resulting molded article has a problem of poor transparency. On the other hand, when it exceeds 0.80 deciliter / gram, the effect of reducing acetaldehyde is lowered. In addition, when the crystallization temperature of the low intrinsic viscosity polyester is less than 140 ° C., the transparency of the molded article is deteriorated, and when it exceeds 180 ° C., the effect of improving the crystallization speed of the plug portion is deteriorated. It is. When the crystallization temperature of the low intrinsic viscosity polyester is lower than 160 ° C., the effect of improving the crystallization rate of the plug portion becomes worse, and when it exceeds 200 ° C., the transparency of the molded article is worsened.

  Further, the intrinsic viscosity of the high intrinsic viscosity polyester (polyester D or polyester F) constituting the polyester composition of the present invention is preferably 0.72 to 0.95 deciliter / gram, more preferably 0.75 to 0.00. 85 deciliter / gram, acetaldehyde content is preferably 8 ppm or less, more preferably 5 ppm or less, and the crystallization temperature at the time of temperature rise is preferably 145 to 177 ° C., more preferably 150 to 175 ° C., the crystallization temperature at the time of temperature drop Is preferably 162 to 190 ° C, more preferably 165 to 180 ° C. When the intrinsic viscosity of the high intrinsic viscosity polyester is less than 0.70 deciliter / gram, the transparency of the obtained molded article is deteriorated. On the other hand, if it exceeds 1.00 deciliter / gram, heat generation during molding becomes intense and the effect of reducing acetaldehyde becomes low. In addition, when the crystallization temperature of the high intrinsic viscosity polyester is less than 140 ° C., the transparency of the molded article is deteriorated, and when it exceeds 180 ° C., the effect of improving the crystallization rate of the plug portion is deteriorated. It is. When the crystallization temperature of the high intrinsic viscosity polyester is lower than 160 ° C., the effect of improving the crystallization speed of the plug portion is deteriorated, and when it exceeds 200 ° C., the transparency of the molded article is deteriorated.

  By using the polyester composition of the present invention having the above characteristics, it is possible to mold at a lower temperature, excellent in transparency and transparent spots (for example, a whitened flow pattern or a partial pattern formed on a molded body) A white molded product or a wrinkled product), and the appearance is greatly improved, and a molded product such as a hollow molded product having a low aldehyde content such as acetaldehyde and excellent flavor retention can be obtained. . In particular, in the case of a thick stretched molded product such as a bottle molded at a low temperature, these effects become remarkable.

  Here, as polyester C or polyester D, polyester E or polyester F, it is possible to use at least one kind of each polyester falling within the above-mentioned characteristic range. It is also possible to use a polyester composition prepared by mixing one polyester as the polyester D so that the moisture content is in the range of 10 to 700 ppm.

  The content of the cyclic ester oligomer in the polyester composition of the present invention is 70% or less, preferably 60% or less, more preferably 50% of the content of the cyclic ester oligomer contained in the melt polycondensation polyester prepolymer of the polyester. % Or less, particularly preferably 35% or less. Here, the polyester generally contains cyclic ester oligomers having various degrees of polymerization, but the cyclic ester oligomer referred to in the present invention is the cyclic ester oligomer having the highest content among the cyclic ester oligomers contained in the polyester. An ester oligomer means, for example, a cyclic trimer in the case of a polyester having ethylene terephthalate as a main repeating unit.

  In the case of PET, in which the polyester is a typical polyester having ethylene terephthalate as the main structural unit, the content of the cyclic trimer of the melt polycondensed polyester prepolymer is about 1.0% by weight. The content of the cyclic trimer in the composition is 0.70% by weight or less, preferably 0.60% by weight or less, more preferably 0.50% by weight or less, particularly preferably 0.35% by weight or less. Is preferred. The lower limit of the cyclic trimer content is 0.20% by weight or more, preferably 0.25% by weight or more, and more preferably 0.30% by weight or more from the viewpoint of economical production. In the case of molding a heat-resistant hollow molded article or the like from the polyester composition of the present invention, heat treatment is performed in a heating mold, but when the cyclic trimer content is 0.70% by weight or more, Oligomer adhesion to the extruder and degassing mouth of the extruder and molding machine at the time of melt molding or to the heated mold surface of the molded body increases rapidly, and the cost for removing them increases and the productivity decreases. In addition, the transparency of the obtained molded product is extremely deteriorated.

  In addition, when the polyester composition of the present invention is melted at a temperature of 290 ° C. for 60 minutes, the increase amount of the cyclic ester oligomer is preferably 0.30% by weight or less, more preferably 0.10% by weight or less. Is preferred. When the increase amount of the cyclic ester oligomer when melted for 60 minutes at a temperature of 290 ° C. exceeds 0.40% by weight, the cyclic ester oligomer increases when the resin for molding is melted, and the oligomer adheres to the surface of the heating mold rapidly. The transparency of the resulting hollow molded body is greatly deteriorated.

  The polyester composition in which the increase amount of the cyclic ester oligomer when melted at a temperature of 290 ° C. for 60 minutes is 0.40% by weight or less is to deactivate the polycondensation catalyst remaining in at least one polyester constituting the polyester composition. Can be manufactured. Of course, it is needless to say that it is most desirable that the polycondensation catalyst of all the polyesters is deactivated. Here, the increase amount of the cyclic ester oligomer when melted at a temperature of 290 ° C. for 60 minutes is the 3 mm thickness of the stepped molded plate obtained from the polyester composition by the molding method described in the “Measurement method” section below. This is the value obtained for the sample from the plate.

Examples of the method of deactivating the polyester polycondensation catalyst include a method of contacting the polyester chip with water, water vapor or water vapor-containing gas.
Examples of the hot water treatment method include a method of immersing polyester in water and a method of applying water on these 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 water temperature is 20 to 180 ° C., preferably 40 to 150 ° C., more preferably 50 to 120 ° C.
The water to be used is preferably water that satisfies at least one of the above (1) to (4), and more preferably water that satisfies all of (1) to (4).

  When the polyester chip is contacted with water vapor or water vapor containing gas, the water vapor or water vapor containing gas or water containing air at a temperature of 50 to 150 ° C., preferably 50 to 110 ° C., is preferably used per 1 kg of the granular polyester. The water vapor is supplied as water vapor in an amount of 0.5 g or more, or is present to bring the granular polyester into contact with water vapor. The contact between the polyester chip and water vapor is usually performed for 10 minutes to 2 days, preferably 20 minutes to 10 hours. The processing method may be either a continuous method or a batch method.

Further, as another means for deactivating the polycondensation catalyst, there is a method in which a phosphorus compound is blended with the polyester and mixed and reacted in a molten state such as during molding to deactivate the polycondensation catalyst.
Examples of the phosphorus compound used include phosphoric acid, phosphorous acid, phosphonic acid, and derivatives thereof. Specific examples thereof are the compounds described above, and these may be used alone or in combination of two or more.

  As a method of blending a phosphorous compound with polyester, a predetermined amount of phosphorous compound is polyester by a method of dry blending the phosphorous compound with the polyester or a method of mixing a polyester masterbatch chip in which a phosphorous compound is melt-kneaded and blended with a polyester chip. And a method of inactivating the polycondensation catalyst by melting in an extruder or a molding machine, a method of immersing chips in a phosphorus compound solution, particularly a phosphoric acid aqueous solution, and a method of adding as a master batch. These phosphorus compounds may be copolymerized with polyester. At this time, a phosphorus compound is added to a polyester of a catalyst (for example, Ge, Sb) whose catalytic activity is not greatly decreased by a phosphorus compound, and blended with a polyester of a catalyst (for example, Ti, Al) whose catalytic activity is decreased by a phosphorus compound. Is also preferable. Thereby, it is possible to easily obtain a polyester having a molecular weight increased to a desired molecular weight while containing a phosphorus compound.

  In addition, a transesterification reaction between the polyesters occurs at the time of molding, but by deactivating the polycondensation catalyst, this transesterification reaction can be suppressed, so that the conditions during molding can be made wider.

  Further, the difference between the crystallization temperature when the polyester C is lowered and the crystallization temperature when the polyester D is lowered, or the crystallization temperature when the polyester E is lowered and the temperature of the polyester F, which constitute the polyester composition of the present invention. The difference in crystallization temperature at the time is desirably within 20 ° C, preferably within 18 ° C, more preferably within 15 ° C, and particularly preferably within 13 ° C. When the difference in the crystallization temperature at the time of temperature drop exceeds 20 ° C., the transparency of the obtained molded product becomes very poor, the crystallization speed fluctuation at the time of crystallization of the plug portion becomes large, and the dimensional accuracy is poor. It is a problem. Here, when the polyester composition of the present invention comprises two or more kinds of polyesters, the difference in the crystallization temperature at the time of temperature decrease is the value of the polyester having the highest temperature crystallization temperature and the value of the lowest temperature crystallization. It represents the difference in the values of polyester with temperature.

  Furthermore, the difference between the crystallization temperature when the polyester C is heated and the crystallization temperature when the polyester D is heated, or the crystallization temperature when the polyester E is heated, which constitutes the polyester composition of the present invention, The difference in the crystallization temperature when the polyester F is heated is within 10 ° C., preferably within 8 ° C., more preferably within 7 ° C., and particularly preferably within 5 ° C. When the difference of the crystallization temperature at the time of the temperature rise exceeds 10 ° C., the fluctuation of the crystallization speed of the obtained unstretched molded product becomes large. As a result, for example, the variation in crystallinity of the heat-crystallized hollow molded body plug portion is large, resulting in large dimensional variation of the plug portion, resulting in poor capping properties and leakage of contents. Here, when the polyester composition of the present invention comprises two or more kinds of polyesters, the difference in the crystallization temperature at the time of temperature increase is the value of the polyester having the highest temperature crystallization temperature and the lowest temperature increase. It represents the difference in the values of polyesters having a time crystallization temperature.

  The shape of the polyester chip according to the present invention may be any of a cylinder shape, a square shape, a spherical shape, a flat plate shape, and the like. The average particle diameter is usually 1.0 to 4 mm, preferably 1.0 to 3.5 mm, and more preferably 1.0 to 3.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.0 to 4 mm and the diameter is about 1.0 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 average weight (W) of the chip is practically in the range of 5 to 40 mg / piece. In addition, when it is necessary to improve the solid-phase polymerization rate or to reduce the content of aldehydes more effectively, the average weight (W) of the chips is also preferably 1 to 5 mg / piece. .

The ratio of the average weight (W) of the polyester constituting the polyester composition of the present invention is 1.00 to 1.30, preferably 1.00 to 1.28, more preferably 1.00 to 1.25, most Preferably it is 1.00-1.20. If the ratio of the average weight exceeds 1.30, aldehydes are generated at the time of molding, which is not preferable because a special nozzle is used to manufacture chips, and it is not preferable. It becomes difficult and low-temperature molding becomes difficult and becomes a problem. In particular, when used for a heat-resistant hollow stretch molded article, if the ratio is out of the range of 1.00 to 1.15, the effect of reducing aldehydes such as acetaldehyde and improving the transparency deteriorates. The blending amount of the polyester is likely to occur, which is not preferable because it causes transparency and thickness unevenness of the stretched hollow molded article of polyester.
Here, when the polyester composition of the present invention is composed of two or more kinds of polyesters, the ratio of the average weight (W) is the ratio of the highest average weight polyester value to the lowest average weight polyester value. To express.

  Further, it is preferable that the variation of the average weight (W) of each polyester chip constituting the polyester composition of the present invention (eg, difference between maximum weight and minimum weight (R), deviation value (σ), etc.) is small. The ratio (R / W) of the difference (R) between the maximum weight (W1) and the minimum weight (W2) and the average weight (W) (R / W) of each of the polyesters is within 0.5, preferably 0.3. Is more preferably within 0.2, and most preferably within 0.1. When the ratio (R / W) exceeds 0.5, when manufacturing a molded product from the polyester composition, the variation of the blending ratio in the time series direction becomes large, so that the intrinsic viscosity and crystallization of the molded product are increased. Variations in properties occur, resulting in a molded product having large variations in thickness spots, stretch spots, transparency spots, mechanical characteristics, and the like. Further, the lower limit of the ratio (R / W) is 0.01, and even if the ratio (R / W) is reduced below this, the improvement effect does not change.

  Further, the difference in crystallinity of the polyester chips constituting the polyester composition of the present invention is preferably 15% or less, preferably 10% or less, more preferably 8% or less. When the difference in crystallinity exceeds 15%, the difference in meltability between the polyesters is large and the effect of improving the fluidity is deteriorated. As a result, the transparency of the polyester unstretched molded body and stretched hollow molded body can be improved. The effect of reducing the content of aldehydes such as acetaldehyde is lost, and the amount of blending of the polyester is likely to occur, and the transparency of polyester unstretched and stretched hollow molded products and the content of aldehydes such as acetaldehyde This is not preferable because it causes fluctuations. Here, when the polyester composition of the present invention comprises two or more kinds of polyesters, the difference in crystallinity is the difference in crystallinity between the largest polyester and the smallest polyester with respect to the degree of crystallinity. is there. Here, the crystallinity of the chip is calculated from the density of the chip obtained by the following method.

  In addition, since the majority of fines are usually more highly crystallized than the chip, the fines contained in the high-density polyester chip remain as an unmelted or incomplete melt at the time of molding, and these are stretch molded articles. In particular, there is a possibility that a whitened product or a wrinkled product is formed in a thick stretched molded product.

  The fine content of each polyester constituting the polyester composition of the present invention is preferably 0.1 to 5000 ppm. The fine content is preferably 0.1 to 3000 ppm, more preferably 0.1 to 1000 ppm, further preferably 0.1 to 500 ppm, and most preferably 0.1 to 100 ppm.

  Further, the difference between the melting point of the fine constituting the polyester composition of the present invention and the melting point of the chip is 15 ° C. or less, preferably 10 ° C. or less, more preferably 5 ° C. or less. In the case where the difference includes fines exceeding 15 ° C., the crystals are not completely melted under the normally used melt molding conditions and remain as crystal nuclei. For this reason, in the case of a hollow molded body, when the hollow molded body plug portion is heated, the crystallization speed becomes faster, so that the crystallization of the plug portion becomes excessive. As a result, since the amount of shrinkage of the plug portion does not fall within the specified value range, the capping portion of the plug portion becomes defective and the contents may leak. In addition, the preform for hollow molding is whitened, so that normal stretching is impossible, thickness unevenness occurs, the crystallization speed is high, and the transparency of the obtained hollow molded body is deteriorated. Fluctuations also become large. In the case of a sheet-like material, the obtained sheet-like material is poor in transparency and has a high crystallization speed, so that normal stretching is impossible, and only a stretched film having large thickness spots and poor transparency can be obtained. Absent.

  However, when trying to obtain a hollow molding preform or sheet-like material with good transparency and stretchability from a polyester composition containing a fine whose melting point of the fine and the melting point of the chip exceeds 15 ° C., It must be melt molded at a temperature about 25-50 ° C. or higher above the melting point of the polyester chip. However, at such a high temperature, the thermal decomposition of the polyester becomes intense, and a large amount of by-products such as acetaldehyde and formaldehyde are generated, which greatly affects the flavor of the contents of the resulting molded body. It becomes. Further, when the polyester composition of the present invention contains at least one resin selected from the group consisting of the following polyolefin resins, polyamide resins, and polyacetal resins, generally these resins are more suitable than the polyester according to the present invention. Since the thermal stability is often inferior, in high temperature molding as described above, it causes thermal decomposition and generates a large amount of by-products. Will be affected.

  When the polyester composition of the present invention is PET, a fine or film-like material having a melting point exceeding 265 ° C. becomes a problem.

  The content of dialkylene glycol copolymerized in the polyester according to the present invention is preferably 0.5 to 7.0 mol%, more preferably 1.0 to 5. mol% of the glycol component constituting the polyester. It is 0 mol%, More preferably, it is 1.0-3.0 mol%. When the amount of dialkylene glycol exceeds 7.0 mol%, the thermal stability is deteriorated, and the decrease in molecular weight becomes large at the time of molding, and the increase in the content of aldehydes is unfavorable. Further, in order to produce a polyester having a dialkylene glycol content of less than 0.5 mol%, it is necessary to select uneconomical production conditions as transesterification conditions, esterification conditions or polymerization conditions. Do not fit. Here, the dialkylene glycol copolymerized in the polyester, for example, in the case of a polyester whose main structural unit is ethylene terephthalate, is a diethylene glycol by-produced during production from ethylene glycol, which is a glycol. Among them, diethylene glycol (hereinafter abbreviated as DEG) copolymerized with the polyester, and in the case of a polyester having 1,3-propylene terephthalate as a main constituent unit, is glycol 1 Of di (1,3-propylene glycol) (or bis (3-hydroxypropyl) ether) by-produced from 1,3-propylene glycol during production, di (1,3-propylene) copolymerized with the polyester Glycol (hereinafter referred to as DPG).

  And the amount of diethylene glycol copolymerized in the polyester according to the present invention, particularly the polyester in which the main repeating unit is composed of ethylene terephthalate is 1.0 to 5.0 mol% of the glycol component constituting the polyester, Preferably it is 1.3-4.5 mol%, More preferably, it is 1.5-4.0 mol%. When the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability is deteriorated, the decrease in molecular weight becomes large at the time of molding, and the increase in acetaldehyde content and formaldehyde content becomes large, which is not preferable. On the other hand, when the diethylene glycol content is less than 1.0 mol%, the transparency of the obtained molded article is deteriorated.

  Furthermore, the polyester composition of the present invention preferably contains 0.1 ppb to 50000 ppm of at least one resin selected from the group consisting of polyolefin resins and polyacetal resins. The blending ratio of the resin used in the present invention to the polyester composition is 0.1 ppb to 10000 ppm, preferably 0.3 ppb to 1000 ppm, more preferably 0.5 ppb to 100 ppm, still more preferably 1.0 ppb to 1 ppm, particularly Preferably, it is 1.0 ppb to 45 ppb. When the blending amount is less than 0.1 ppb, the crystallization speed becomes very slow and the crystallization of the plug part of the hollow molded body becomes insufficient. Therefore, if the cycle time is shortened, the shrinkage amount of the plug part is specified. Since it does not fall within the value range, capping defects occur, and the heat-fixed mold for forming heat-resistant hollow molded products is heavily soiled. When trying to obtain a transparent hollow molded product, the mold is frequently cleaned. There must be. On the other hand, if it exceeds 50000 ppm, the crystallization speed will be high, and the crystallization of the plug part of the hollow molded body will be excessive. Leaking, or the unstretched molded body for hollow molded bodies is whitened, which makes normal stretching impossible.

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

  The production of the polyester composition blended with the polyolefin resin or the like in the present invention is a method in which a resin such as the polyolefin resin is directly added to the polyester according to the present invention so that its content falls within the above range and melt-kneaded. In addition to conventional methods such as a method of adding and melt-kneading as a master batch, the resin may be produced at the production stage of the polyester according to the present invention, for example, during melt polycondensation, immediately after melt polycondensation, immediately after precrystallization, In solid phase polymerization, immediately after solid phase polymerization, etc., or in the process from the end of the production stage to the molding stage, it can be added directly as a granular material, or it can be added to the present invention. According to a method in which the polyester chip is mixed by a method such as bringing it into contact with the resin member under flow conditions, or a method of melt-kneading after the contact treatment And it can also be.

  Here, as a method of bringing the polyester chip into contact with the resin member under flow conditions, it is preferable that the polyester chip is brought into collision contact with the member within the space where the resin member is present. For example, immediately after the melt polycondensation of polyester, immediately after precrystallization, immediately after solid-phase polymerization, etc., at the time of filling and discharging the transport container in the transport stage as a product of polyester chips, etc. When the molding machine is inserted in the chip molding stage, a part of pneumatic transportation piping, gravity transportation piping, silo, magnet catcher magnet part, etc. is made of the resin, or the resin film, sheet, molded body, etc. Or lining the resin, or installing the resin member such as a rod-like or net-like body in the transfer path To include a method of transferring the polyester chips. 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.

Moreover, polyamide, polyesteramide, a low molecular weight amino group containing compound, and a hydroxyl group containing compound can be mix | blended with the polyester composition of this invention as an aldehyde reducing agent.
Examples of the polyamide blended as the aldehyde reducing agent include at least one polyamide selected from aliphatic polyamides such as nylon 6 and nylon 66 and partially aromatic polyamides such as nylon-MXD6.
Polyester amides include terephthalic acid, polyester amide produced from 1,4-cyclohexanedimethanol and polyethyleneimine, polyester amide produced from isophthalic acid, 1,4-cyclohexanedimethanol and hexamethylenediamine, and terephthalic acid. Polyesteramides made from adipic acid, 1,4-cyclohexanedimethanol and hexamethylenediamine, polyesteramides made from terephthalic acid, 1,4-cyclohexanedimethanol and bis (p-aminocyclohexyl) methane and their A mixture etc. are mentioned.

  The polyamide or polyester amide used preferably has a secondary transition point measured by DSC (differential scanning calorimeter) of 50 to 120 ° C. When the secondary transition point is less than 50 ° C., it is not preferable because it is fused during the drying step or extrusion with the polyester composition, or cannot be quantitatively extruded. Moreover, when exceeding 120 degreeC, when extending | stretching a polyester unstretched molded object, it will not be stretched | uniformly uniformly but a thickness spot etc. will arise and it is unpreferable.

  The shape of the polyamide or polyesteramide chip blended in the polyester composition of the present invention may be any of a cylinder shape, a square shape, a spherical shape, a flat plate shape, and the like. The average particle size is usually in the range of 1.0 to 5 mm, preferably 1.2 to 4.5 mm, more preferably 1.5 to 4.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.0 to 4 mm and the diameter is about 1.0 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 average weight of the chip is practically in the range of 1 to 50 mg / piece.

Examples of the low molecular weight amino group-containing compound include aliphatic amine compounds such as stearylamine, 1,8-diaminonaphthalate, 3,4-diaminobenzoic acid, 2-aminobenzamide, N, N′-1,6- Examples thereof include aromatic amine compounds such as hexanedibis (2-aminobenzamide) and 4,4′-diaminodiphenylmethane, triazine compounds such as melamine and benzoguanamine, and amino acids.
Examples of the hydroxyl group-containing compound include polyvinyl alcohol, ethylene vinyl alcohol polymer, sugar alcohol, and trimethylolpropane.

  These polyamide compounds, low molecular weight amino group-containing compounds, or hydroxyl group-containing compounds may be used alone or in admixture at an appropriate ratio.

  The aldehyde reducing agent is, for example, used in an amount of 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the polyester composition of the present invention. Can do.

  The aldehyde reducing agent can be blended by adding a predetermined amount of aldehyde reducing agent at any reaction stage from the production of a low-polymerization degree oligomer of polyester to the production of polyester polymer. For example, the aldehyde reducing agent may be added to a reactor such as an esterification reactor or a polycondensation reactor in an appropriate form such as a fine granule, powder, or melt, or from the reactor to a reactor in the next step. The aldehyde reducing agent or a mixture of the polyester and the polyester may be introduced in a molten state into a transport pipe for the polyester reactant. Furthermore, if necessary, the obtained chip can be subjected to solid phase polymerization in a high vacuum or in an inert gas atmosphere.

  It can also be obtained by a method of mixing a polyester composition and an aldehyde reducing agent by a conventionally known method or a method of mixing an aldehyde reducing agent with a mixture of two or more kinds of polyesters. For example, polyamide chips and two types of polyester chips with different IVs are dry blended with a tumbler, V-type blender, Henschel mixer, etc., and the dry blended mixture once with a single screw extruder, twin screw extruder, kneader, etc. Examples include those obtained by melting and mixing as described above, and those obtained by subjecting chips from the molten mixture to solid phase polymerization in a high vacuum or inert gas atmosphere as necessary.

  Further, a method in which a solution in which the polyamide or the like is dissolved in a solvent such as hexafluoroisopropanol is adhered to the surface of the polyester chip, and the polyester is collided with the member in a space where the polyamide member is present. Examples include a method of attaching the polyamide to the surface of the polyester chip.

  The polyester composition of the present invention can be formed into a film, a sheet, a container, or other molded body by using a commonly used melt molding method, or coated on another substrate by a melt extrusion method. A coated coating can be formed.

  The sheet-like material comprising the polyester composition of the present invention can be produced by a means known per se. For example, it can be manufactured using a general sheet forming machine equipped with an extruder and a die.

  The sheet-like material can be formed into a recup shape or a tray shape by pressure forming or vacuum forming. Moreover, the polyester molding from the polyester composition of this invention can be used also for the use of the tray-shaped container for cooking food with a microwave oven and / or an oven range, or heating frozen food. . In this case, after the sheet-like material is formed into a tray shape, it is thermally crystallized to improve heat resistance.

  Moreover, the polyester composition of this invention can be used also as one component layer which took the form of the film form or the coating-film form in composite molded objects, such as a laminated molded object and a laminated film. In particular, it is used for manufacturing containers and the like in the form of a laminate with PET. Examples of laminated molded products include a two-layer structure composed of two layers of an outer layer made of the polyester composition of the present invention and an inner layer of PET, or composed of two layers of an inner layer made of the polyester composition of the present invention and an outer layer of PET. A molded article having a two-layer structure, a three-layer structure composed of an intermediate layer containing the polyester composition of the present invention and an outer layer and an innermost layer of PET, or an intermediate layer between the outer layer and innermost layer containing the polyester composition of the present invention and PET Examples include a three-layered molded body composed of layers, a five-layered molded body composed of an intermediate layer containing the polyester composition of the present invention, an innermost layer of PET, a central layer, and an innermost layer. In the PET layer, other gas barrier resins, ultraviolet blocking resins, heat resistant resins, recovered products from used polyethylene terephthalate bottles, and the like can be mixed and used at an appropriate ratio.

  Other examples of the laminated molded body include a laminated molded body with a resin other than polyester such as polyolefin, and a laminated molded body with a different type of substrate such as paper or a metal plate.

  There is no restriction | limiting in particular in the thickness of the said laminated molded object, and the thickness of each layer. The laminated molded body can be used in various shapes such as a sheet-like material, a film-like material, a plate-like material, a hollow body, and a container.

  The laminate can be produced by co-extrusion using a number of extruders corresponding to the type of the resin layer and a multi-layered multi-die, or with a number of injection machines corresponding to the type of the resin layer. It can also be done by co-injection using an injection runner and injection mold.

Another application of the polyester composition of the present invention is a film laminated on one or both sides of a laminated metal plate. Examples of the metal plate used include tinplate, tin-free steel, and aluminum.
As a laminating method, a conventionally known method can be applied, and it is not particularly limited, but it is preferable to carry out by a thermal laminating method that can achieve organic solvent-free and can avoid adverse effects on the taste and odor of food products due to the residual solvent. In particular, the thermal laminating method by energization processing of a metal plate is particularly recommended. In the case of double-sided lamination, lamination may be performed simultaneously or sequentially.
Needless to say, a film can be laminated to a metal plate using an adhesive.

  Moreover, a metal container is obtained by shape | molding using the said laminated metal plate. The method for forming the metal container is not particularly limited. Further, the shape of the metal container is not particularly limited, but is preferably applied to a so-called two-piece can produced by a molding process such as drawing, drawing and ironing, and stretch draw molding. The present invention can also be applied to a so-called three-piece can in which a top cover suitable for filling a food product such as a coffee drink is wrapped to fill the contents.

  The method for producing a polyester molded body from the polyester composition of the present invention will be briefly described below, but is not limited thereto.

  Water content of the polyester composition is obtained by combining polyester A having a moisture content reduced to about 100 ppm or less by heat drying under reduced pressure or heat drying under an inert gas, and polyester B having a moisture content of 0.05 to 0.6% by weight. It can be mixed quantitatively before molding so that the rate is in the range of 10 to 700 ppm, and a molded body or a covering can be molded using a melt molding method as described below. In the case of polyester C and polyester D, or polyester F and polyester E, molding can be performed in the same manner.

  As the melt molding conditions, it is generally important to set the molten resin temperature in the range of 240 to 305 ° C, preferably 245 to 295 ° C, more preferably 250 to 285 ° C. Here, the molten resin temperature refers to a temperature at which the resin injected from the tip of a nozzle of an injection molding machine or the like is immediately measured with, for example, a thermocouple thermometer.

  Also, the melt residence time in the molding machine can be set by arbitrarily selecting the shape of the extruder screw, L / D, etc. and the amount of extrusion in the case of extrusion molding, and in the case of injection molding, the injection molding machine The cycle time, the metering stroke (screw back amount), etc. are arbitrarily set, and are preferably set in the range of 10 to 300 seconds, more preferably 10 to 200 seconds, and most preferably 10 to 100 seconds. Here, the melt residence time is a residence time in a state where the resin is melted in the molding machine. Specifically, the melt residence time is a time during which the resin is melted and held in a cylinder in the molding machine and in a hot runner or a die. That is.

  In the present invention, the polyester composition according to claim 2 or claim 2 is controlled by controlling the molten resin temperature in the range of 240 to 305 ° C and setting the melt residence time in the range of 5 to 500 seconds. The polyester composition according to Item 3, having a low content of aldehydes such as acetaldehyde and a cyclic trimer content, excellent flavor retention, excellent transparency, and transparent spots (for example, formed in a molded product) A hollow molded body having no problem in the shape of the plug portion after crystallization can be obtained. In particular, in the case of a wall-thickened molded article such as a bottle, these effects become significant.

  When the temperature of the molten resin is less than 240 ° C., the torque load of an injection molding machine or the like is large and molding becomes difficult, and the obtained molded product becomes extremely poor in transparency. Moreover, when the temperature exceeds 305 ° C., the thermal decomposition becomes intense and the content of aldehyde such as acetaldehyde increases, which is a problem. If the melt residence time is less than 5 seconds, the transparency of the molded product becomes poor due to insufficient melting, and if it exceeds 500 seconds, the transparency of the molded product becomes very good, but it contains aldehydes such as acetaldehyde. The amount increases, the molding cycle becomes longer, and the productivity of the molded body decreases.

Below, the specific manufacturing method about the extending | stretching molded object in the case of PET is demonstrated easily.
In producing a stretched hollow molded body, a foam molded from the polyester composition of the present invention is stretch blow molded, and an apparatus conventionally used in blow molding of PET can be used. Specifically, for example, once a preform is formed by injection molding or extrusion molding, the plug part and the bottom part are processed as it is, and then reheated, and then biaxial stretch blow molding such as hot parison method or cold parison method The law applies. The molding temperature in this case, specifically, the temperature of each part of the cylinder of the molding machine and the nozzle is usually in the range of 260 to 305 ° C. The stretching temperature is usually 70 to 120 ° C., preferably 90 to 110 ° C., and the stretching ratio is 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 can be used as it is, but in particular in the case of beverages that require hot filling, such as fruit juice beverages and oolong teas, it is generally heat-set in a blow mold and heat resistant. Used to impart sex. The heat setting is usually performed at 100 to 200 ° C., preferably 120 to 180 ° C. for several seconds to several hours, preferably several seconds to several minutes, under tension by compressed air or the like.

  In addition, in order to impart heat resistance to the plug part, the plug part of the preform obtained by injection molding or extrusion molding is crystallized in a far-infrared or near-infrared heater installation oven, or after the bottle is formed, The stopper is crystallized with the heater.

  The polyester composition of the present invention can also be used for the production of a stretched hollow molded body by a so-called compression molding method in which a preform obtained by compression molding a melt mass cut after melt extrusion is stretch blow molded. Can do.

  In producing a stretched film, the stretching temperature is usually 80 to 130 ° C. Stretching may be uniaxial or biaxial, but biaxial stretching is preferred from the viewpoint of film physical properties. In the case of uniaxial stretching, the stretching ratio is usually 1.1 to 10 times, preferably 1.5 to 8 times. In the case of biaxial stretching, the longitudinal and transverse directions are usually 1.1 to 8 times, respectively. Preferably, it may be performed in a range of 1.5 to 5 times. The vertical / horizontal magnification is usually 0.5 to 2, preferably 0.7 to 1.3. The obtained stretched film can be further heat-set to improve heat resistance and mechanical strength. The heat setting is usually performed under tension at 120 to 240 ° C., preferably 150 to 230 ° C., usually for several seconds to several hours, preferably several tens of seconds to several minutes.

  In the polyester composition of the present invention, known ultraviolet absorbers, antioxidants, oxygen scavengers, lubricants added from the outside, lubricants precipitated internally during the reaction, mold release agents, nucleating agents, stability Various additives such as an agent, an antistatic agent, a bluing agent, a dye, and a pigment, and a polyamide resin from metaxylylenediamine and adipic acid may be added to improve oxygen permeability.

  In addition, when the polyester composition of the present invention is used for a film, the polyester composition contains calcium carbonate, magnesium carbonate, barium carbonate in order to improve handling properties such as slipping property, winding property, and blocking resistance. , Inorganic particles such as calcium sulfate, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, organic salt particles such as terephthalate such as calcium oxalate, calcium, barium, zinc, manganese, magnesium, divinylbenzene, styrene, acrylic Inactive particles such as crosslinked polymer particles such as acid, methacrylic acid, acrylic acid or a vinyl monomer of methacrylic acid, or a copolymer thereof can be contained.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
The main characteristic value measurement methods will be described below.

(1) Intrinsic viscosity of polyester (IV)
It calculated | required from the solution viscosity at 30 degreeC in a 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio) mixed solvent. The IV of the polyester composition was a weighted average value calculated from the IV of the constituent polyester.

(2) Polyethylene glycol content of polyester (hereinafter referred to as [DEG content])
Decomposition with methanol, the amount of DEG was quantified by gas chromatography, and expressed as a ratio (mol%) to the total glycol components.

(3) Content of cyclic trimer of polyester (hereinafter referred to as “CT amount”)
300 mg of the frozen and ground sample is dissolved in 3 ml of a hexafluoroisopropanol / chloroform mixed solution (volume ratio = 2/3), and further diluted with 30 ml of chloroform. To this is added 15 ml of methanol to precipitate the polymer, followed by filtration. The filtrate was evaporated to dryness, adjusted to a constant volume with 10 ml of dimethylformamide, and the cyclic trimer was quantified by high performance liquid chromatography. The cyclic trimer content of the polyester composition was determined by calculation from the blending ratio of each constituent polyester and the cyclic trimer content. A sample was taken from a 3 mm plate to measure the content of the cyclic trimer on the molded plate.

(4) Increasing amount of cyclic trimer at the time of melting of polyester (△ CT amount)
A sample was taken from a 3 mm-thick plate molded at 270 ° C. in (15) below, dried under reduced pressure at 140 ° C. and 0.1 mmHg or less for about 16 hours, 3 g of the polyester sample was placed in a glass test tube, and nitrogen was added. It is immersed in an oil bath at 290 ° C. for 60 minutes under an atmosphere and melted. The increase amount of the cyclic trimer at the time of melting is obtained by the following equation.
In addition, the cyclic trimer content before melting was a weighted average value of the cyclic trimer content of the polyester constituting the polyester composition.
Increase amount of cyclic trimer at the time of melting (wt%) =
Cyclic trimer content after melting (wt%)-cyclic trimer content before melting (wt%)

(5) Acetaldehyde content of polyester (hereinafter referred to as “AA content”)
Sample / distilled water = 1 g / 2 cc of glass ampoule substituted with nitrogen was sealed and subjected to extraction treatment at 160 ° C for 2 hours. After cooling, acetaldehyde in the extract was measured by high-sensitivity gas chromatography. The concentration was expressed in ppm. A sample was taken from a 2 mm plate for measuring the AA content of the molded plate.

(6) Density (ρ) and crystallinity (CR) of polyester chip
The density (ρ) of the chip at 30 ° C. was measured with a density gradient tube of calcium nitrate / water solution.
The crystallinity was calculated from the following formula.
CR = 100ρ _c (ρ−ρ _a ) / ρ (ρ _c −ρ _a )
Where ρ is the density of the chip
ρ _a : amorphous density (1.335 g / cm ³ )
ρ _c : crystal density (1.455 g / cm ³ )

(7) Ratio of average weight (W) and average weight of polyester chip (W _A / W _B )
After removing fines with ion-exchanged water, the weight of 100 dried polyester chips was measured, and the average value was defined as the average weight (W). When the polyester composition is a mixture of two kinds of polyesters, the ratio of the average weight of the polyester chips between the two kinds (W _A / W _B ) is the average weight of the polyester chips having a larger average weight among the two kinds. and W _a, the average weight of the average weight of small polyester chips as _{W B,} was calculated _W a / W _B. When the two types of polyester chips have the same average weight, W _A / W _B is 1.00. Moreover, when it consists of 2 or more types of polyester, it calculates as mentioned above for 2 types of polyester with many mixing ratios.
In this case, the selection of 100 chips was performed by excluding abnormally sized chips. The specific chip exclusion method is as follows.
In calculating the average weight (W) of the chips, 100 chips were randomly selected, and after calculating the average weight (W), the chips having a weight of less than 0.5 W and the chips having a weight of more than 2 W were excluded and excluded. A number of chips were picked again at random, replenished and 100 averages recalculated. This was done until all 100 chips were within 0.5W-2W.

(8) Moisture content of polyester The moisture content was measured with Karl Fischer (CA-100 type and VA-100 type) manufactured by Mitsubishi Chemical.
The moisture content of the polyester composition was determined by calculation from the blending ratio and moisture content of each constituting polyester.

(9) Sodium content and calcium content of polyester About 5 to 10 g of a sample is put in a platinum crucible and incinerated at about 550 ° C., then dissolved in 6N hydrochloric acid and evaporated to dryness, and the residue is dissolved in 1N hydrochloric acid. This solution was measured by atomic absorption spectrometry.

(10) Silicon content of polyester About 5 to 10 g of a sample is put in a platinum crucible and incinerated at about 550 ° C., then sodium carbonate is added and dissolved by heating, and dissolved in 1N hydrochloric acid. This solution was measured with an inductively coupled plasma optical emission spectrometer manufactured by Shimadzu Corporation.

(11) Measurement of Fine Content About 0.5 kg of resin is sieved with a screen (A) having a mesh size of 5.6 mm according to JIS-Z8801 and a screen having a mesh size of 1.7 mm (diameter) 20 cm) (B) was placed on a sieve combined in two stages, and sieved at 1800 rpm for 1 minute with a swing type sieve shaker SNF-7 manufactured by Terraoka. This operation was repeated and a total of 20 kg of resin was sieved. However, when the fine content is small, the amount of the sample is appropriately changed.
The fine sieved under the sieve (B) is washed with a 0.1% aqueous cationic surfactant solution, then washed with ion-exchanged water, and filtered through a G1 glass filter manufactured by Iwaki Glass Co., Ltd. It was. These were dried together with a glass filter in a dryer at 100 ° C. for 2 hours, then cooled and weighed. Again, the same operations of washing and drying with ion-exchanged water were repeated to confirm that the weight became constant, and the weight of the glass filter was subtracted from this weight to obtain the fine weight. The fine content is the fine weight / the total resin weight that has been sieved.

(12) Measurement of fine melting peak temperature (hereinafter referred to as “fine melting point”) Measured using a differential scanning calorimeter (DSC) manufactured by Seiko Denshi Kogyo Co., Ltd., RDC-220. In (11), the finely collected fine polyester was frozen and pulverized and mixed, and then dried under reduced pressure at 25 ° C. for 3 days. From now on, 4 mg of sample was used for one measurement, and the DSC was performed at a heating rate of 20 ° C./min. Measure and obtain the melting peak temperature on the highest temperature side of the melting peak temperature. The measurement is performed on a maximum of 10 samples, and the average value of the melting peak temperatures on the highest temperature side is obtained. If there is a single melting peak, the temperature is determined.

(13) Crystallization temperature (Tc1) when the molded body is heated and crystallization temperature (Tc2) when the temperature is lowered
Measured with a differential thermal analyzer (DSC), RDC-220, manufactured by Seiko Electronics Industry Co., Ltd. Using 10 mg of a sample from the center of a 2 mm thick plate of the molded plate of (15) below. The temperature was raised at a rate of temperature rise of 20 ° C./minute and held at 290 ° C. for 3 minutes, then the temperature was lowered from 290 ° C. to 240 ° C. at 10 ° C./minute, and further from 240 ° C. to 130 ° C. at 7 ° C./minute. The temperature dropped. The peak temperature of the crystallization peak observed at the time of temperature rise is defined as the crystallization temperature (Tc1) at the time of temperature increase, and the peak temperature of the crystallization peak observed at the time of temperature decrease is defined as the crystallization temperature (Tc2).

(14) Haze (Fraction%)
A sample was cut from the molded product (wall thickness 4 mm) of the following (15) and measured with a Nippon Denshoku Co., Ltd. haze meter, model NDH2000.

(15) Molding of stepped molded plate
1) Molding of Stepped Molding Plate A polyester sample of the following 2) or a sample of the polyester composition of the following 3) was subjected to an injection molding machine M-150C-DM type injection molding machine manufactured by Meiki Seisakusho. 2 mm to 11 mm having a gate part (G) as shown in (A part thickness = 2 mm, B part thickness = 3 mm, C part thickness = 4 mm, D part thickness = 5 mm, E part thickness = 10 mm) , F portion thickness = 11 mm) was formed by injection molding.
In order to prevent moisture absorption during molding, the inside of the molding material hopper was purged with a dry inert gas (nitrogen gas). As plasticizing conditions by the M-150C-DM injection molding machine, feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, cylinder temperature is 45 ° C., 250 ° C., and immediately below the hopper, and The cylinder temperature after the nozzle was included (hereinafter referred to as Sx) was set to 280 ° C. The injection conditions are 20% for injection speed and holding pressure, and the injection pressure and holding pressure are adjusted so that the weight of the molded product is 146 ± 0.2g. In this case, the holding pressure is 0.5MPa lower than the injection pressure. It was adjusted.
The upper limit of the injection time and pressure holding time is set to 10 seconds and 7 seconds, respectively, and the cooling time is set to 50 seconds. The total cycle time including the time for taking out the molded product is about 75 seconds.
Although the temperature of the mold is always controlled by introducing cooling water having a water temperature of 10 ° C., the mold surface temperature at the time of stable molding is around 22 ° C.
The molding temperature refers to the set temperature of the barrel including the nozzle.
The test plate for evaluating the characteristics of the molded product was arbitrarily selected from the 11th to 18th shots of the stable molded product after the molding material was introduced and the resin was replaced.

2) Molding of various polyesters used in Examples and Comparative Examples The polyesters of Table 1 are dried at 140 ° C. for about 16 hours using a vacuum dryer to a moisture content of 100 ppm or less and molded by the method of 1) above. The forming plate Tc1 and the forming plate Tc2 shown in Table 1 are measured values for a stepped forming plate formed at a forming temperature of Sx = 290 ° C.

3) Molding of polyester composition in Examples and Comparative Examples Samples of the polyester composition in Table 2 are molded by the method of 1) above.
For the measurement of the cyclic trimer content (CT amount) of the molded plate, a molded plate of Sx = 290 ° C. was used, and for measuring the molded plate AA content (ppm) and the molded plate haze (%), Sx = A molded plate at 280 ° C. was used.

4) Various measuring plates 2 mm thick plate (part A in FIG. 1) is for crystallization temperature (Tc1) during temperature rise, crystallization temperature (Tc2) during temperature drop and acetaldehyde content measurement, 3 mm thickness The plate (part B in FIG. 1) was used to measure the content of the trimer (CT amount) of the molded plate and to measure the amount of increase in the cyclic trimer (ΔCT amount) during melting. (Part D) is used for haze (degree of haze) measurement.

(16) Molding of hollow molded body 1) Molding of preform In order to prevent moisture absorption of the chip during molding using the polyester composition of Table 2, the molding material hopper is purged with a dry inert gas (nitrogen gas). went.
The plasticizing conditions of the M-150C-DM injection molding machine manufactured by Meiki Seisakusho Co., Ltd. are as follows: feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, weighing position 50 mm, cylinder temperature from directly below the hopper In order, the temperature was set to 45 ° C., 250 ° C., and thereafter the molten resin temperature including the nozzle was 280 ° C. The injection conditions were such that the injection speed and holding pressure were 10%, and the injection pressure and holding pressure were adjusted so that the weight of the molded product was 58.6 ± 0.2 g. Adjusted to 5 MPa lower. The cooling time is set to 20 seconds, and the total cycle time including the molded product take-out time is approximately 42 seconds. The preform has an outer diameter of 29.4 mm, a length of 145.5 mm, and a wall thickness of about 3.7 mm.
The mold is always controlled by introducing cooling water having a water temperature of 18 ° C., but the mold surface temperature at the time of molding stability is around 29 ° C. The preform for property evaluation was arbitrarily selected from stable molded products 20 to 50 shots after the start of molding after introducing the molding material and replacing the resin.

2) Molding of stretched hollow molded body (bottle) The preform was biaxially stretched and blown by a LB-01E molding machine manufactured by CORPOPLAST to mold a container (body thickness 0.45 mm) having a capacity of 1500 cc. The stretching temperature was controlled at 100 ° C.

(17) Appearance of Hollow Molded Body Twenty hollow molded bodies from the tenth molding start of (16) were visually observed and evaluated as follows.
◎: Transparent and no appearance problem ○: Slightly poor transparency but no whitened flow or whitened product △: There is a little whitened flow pattern or whitened product ×: White flowed pattern or whitened hollow molded product There is a monster

(18) Sodium content, Magnesium content, Calcium content and Silicon content of chip cooling water or treated water Chip cooling water is collected and filtered through a 1G1 glass filter manufactured by Iwaki Glass Co., Ltd., and the filtrate is manufactured by Shimadzu Corporation. Measurements were made with an inductively coupled plasma emission spectrometer.

(Polyester 1 (Pes1))
High purity terephthalic acid and ethyl glycol are continuously supplied to the first esterification reactor containing the reactants in advance, and the average residence time is 3 hours at about 250 ° C. and 0.5 kg / cm ² G with stirring. Reaction was performed. In addition, an ethylene glycol solution of amorphous germanium dioxide (no X-ray crystal peak and no Raman spectrum) and a ethylene glycol solution of phosphoric acid were continuously fed separately to the first esterification reactor. . This reaction product was sent to the second esterification reactor, and the reaction was carried out with stirring at about 260 ° C. and 0.05 kg / cm ² G to a predetermined reactivity. The esterification reaction product is continuously sent to the first polymerization reactor under stirring at about 265 ° C. and 25 torr for 1 hour, then stirred in the second polymerization reactor at about 265 ° C. and 3 torr for 1 hour, and further Polymerization was conducted at about 275 ° C. and 0.5 to 1 torr with stirring in the third polymerization reactor. The obtained PET resin had an intrinsic viscosity (IV) of 0.53 deciliter / gram and a DEG content of 2.6 mol%.
The cooling water at the time of chip formation is ion-exchanged water having a sodium content of 0.1 ppm, a calcium content of about 0.1 ppm, a magnesium content of about 0.06 ppm, and a silicon content of about 0.7 ppm. Using.
After fine removal of this resin, it was subsequently crystallized at about 155 ° C. in a nitrogen atmosphere, further preheated to about 200 ° C. in a nitrogen atmosphere, and then sent to a continuous solid-phase polymerization reactor for solid phase polymerization at about 207 ° C. in a nitrogen atmosphere. . After the solid-phase polymerization, the fine particles were removed by continuous treatment in the sieving step and the fine removal step.
The obtained PET has an intrinsic viscosity of 0.69 deciliter / gram, an acetaldehyde (AA) content of 3.9 ppm, a cyclic trimer content of 0.40% by weight, a chip shape of an elliptic cylinder, and an average chip weight. (W) was 24.1 mg, the crystallinity of the chip was 53.0%, the fine content was about 50 ppm, the fine melting point was about 252 ° C., and the moisture content was 40 ppm. This was filled in an airtight container in an inert gas atmosphere, and sealed and stored until molding. All the following polyesters were also stored in a sealed container until molding. The properties of the obtained PET are shown in Table-1.

(Polyester 2 (Pes2))
A polyester 2 was obtained by reacting in the same manner as the polyester 1 except that the amount of polycondensation catalyst added and the solid phase polymerization time were changed. The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, silicon content, fine content and fine melting point were the same as those of polyester 1.

(Polyester 3 (Pes3), 4 (Pes4))
A polyester 3 was obtained by reacting in the same manner as the polyester 1 except that the solid phase polymerization temperature was changed. In addition, this was left to stand at room temperature to absorb moisture to obtain polyester 4. The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, silicon content, fine content and fine melting point were the same as those of polyester 1.

(Polyester 5 (Pes5), 6 (Pes6))
Using ethylene glycol solution of antimony trioxide as a polycondensation catalyst, sodium content is about 9.5ppm, calcium content is about 11.3ppm, magnesium content is about 6.1ppm, silicon content as cooling water when chipping Were reacted in substantially the same manner as in polyester 1 except that 15.0 ppm of water was used to obtain polyesters 5 and 6. However, in the case of polyester 5, the solid phase polymerization time was shortened.
The properties of the obtained PET are shown in Table-1. The fine content and its melting point were similar to those of polyester 1. However, the sodium content was 6.2 ppm, the calcium content was 7.8 ppm, and the silicon content was 12.0 ppm.

(Polyester 7 (Pes7), 8 (Pes8), 10 (Pes10))
Polyesters 7, 8, and 10 were obtained by reacting in the same manner as for polyester 1 except that the amount of polycondensation catalyst added and the solid phase polymerization time were changed, and then dipping in distilled water at room temperature to absorb moisture. The moisture content was adjusted by changing the immersion time.
The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, silicon content, fine content and fine melting point were the same as those of polyester 1.

(Polyester 9 (Pes9))
A polyester 9 was obtained by reacting in the same manner as the polyester 1 except that the solid phase polymerization time was changed. The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, silicon content, and fine melting point were similar to those of polyester 1.

(Polyester 11 (Pes11))
PET obtained by reacting in the same manner as polyester 8 was stored without moisture absorption and subjected to molding.

(Polyester 12 (Pes12))
A prepolymer was obtained by melt polycondensation in the same manner as polyester 1 except that the amount of polycondensation catalyst added was changed.
The resulting prepolymer was finely removed and then charged into a rotary vacuum solid-phase polymerization apparatus, and crystallized at 70 to 160 ° C. under reduced pressure while rotating, followed by solid-phase polymerization at 210 to 215 ° C. After solid-phase polymerization, fines were removed in the sieving step. The properties of the obtained PET are shown in Table-1. The fine content was about 120 ppm, the melting point was 268 ° C., and the sodium content, calcium content, and silicon content were similar to those of polyester 1.

(Polyester 13 (Pes13), 14 (Pes14))
As a polycondensation catalyst, the reaction is carried out in the same manner as for polyester 1 except that an ethylene glycol solution of basic aluminum acetate, Irganox 1222 (manufactured by Ciba Specialty Chemicals) and an ethylene glycol solution in which ethylene glycol is preheated are used. Polyesters 13 and 14 were obtained.
The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, silicon content, fine content and fine melting point were the same as those of polyester 1.

(Polyester 15 (Pes15), 16 (Pes16))
Polyesters 15 and 16 were obtained by reacting in the same manner as polyester 1 except that an ethylene glycol solution of titanium tetrabutoxide and an ethylene glycol solution of magnesium acetate tetrahydrate were used as the polycondensation catalyst.
The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, silicon content, fine content and fine melting point were the same as those of polyester 1.

(Polyester 17 (Pes17), 18 (Pes18))
In the first esterification reactor containing the reactants in advance, high-purity terephthalic acid (corresponding to 98.0 mol% of the total acid component), isophthalic acid (2.0 mol% of the total acid component) and ethyl glycol Were reacted in the same manner as polyester 1 except that polyesters 17 and 18 were obtained.
The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, silicon content, fine content and fine melting point were the same as those of polyester 1.

Example 1
A molded plate obtained by molding the polyester composition obtained by blending the above polyester 1 and polyester 7 pellets at a ratio of 7: 3 at a ratio of 7: 3 at 280 ° C. and 290 ° C. by the method (15), and (16) Evaluation by a hollow molded body obtained by molding by the above method was carried out. The results are shown in Table 2.
The amount of CT increase during molding was 0%, the haze of the molded plate was 6.5%, the AA content of the molded plate was 10.3 ppm, and there were no problems with the appearance of the hollow molded container. The amount of increase in cyclic trimer (ΔCT amount) at the time of melting of the molded plate was 0.38% by weight.

(Examples 2 to 5)
According to the composition shown in Table 2, the polyester composition of each Example was evaluated in the same manner as in Example 1. The results are shown in Table 2. All the evaluated characteristics were as good as in Example 1.

(Example 6)
The polyester compositions having the compositions shown in Table 2 were evaluated in the same manner as in Example 1. The results are shown in Table 2. All the evaluated characteristics were as good as in Example 1.

(Comparative Examples 1 and 2)
As shown in Table 2, the polyester compositions of Comparative Examples 1 and 2 were evaluated in the same manner as in Example 1.
Obviously, the amount of CT increase at the time of molding was large, the haze value of the molded plate and the content of the molded plate AA were large, and the appearance of the hollow molded body was also poor compared with the examples. The results are shown in Table 2.

(Comparative Example 3)
As shown in Table 2, the polyester composition of Comparative Example 3 was evaluated in the same manner as in Example 1.
The results are shown in Table 2. Although the AA content of the molded plate was small, the transparency of the molded plate and the hollow molded body deteriorated.

(Comparative Examples 4-6)
As shown in Table 2, the polyesters of Comparative Examples 4 to 6 were evaluated in the same manner as in Example 1.
Obviously, the amount of CT increase at the time of molding was large, the haze value of the molded plate and the content of the molded plate AA were large, and the appearance of the hollow molded body was also poor compared with the examples. The results are shown in Table 2.

  Since the present invention has improved flow characteristics, it can be molded at a low temperature, has excellent transparency, has a small amount of aldehydes and cyclic ester oligomers during molding, and has a molded body. Provides a polyester composition that provides a molded article or coating excellent in mechanical properties such as pressure resistance. In addition, since the polyester composition of the present invention has improved flow characteristics, there is little distortion during molding, and a molded article having excellent heat-resistant dimensional stability, particularly a hollow molded article, can be efficiently produced by high-speed molding, and The present invention provides a polyester composition excellent in long-term continuous moldability, which gives a molded article having very good pressure resistance and heat-resistant dimensional stability, and which does not stain the mold, and a method for producing the same. The polyester composition of the present invention can meet high quality requirements in the field of containers, sheets and the like.

Plan view of stepped plate Side view of stepped plate

Claims (10)

A polyester composition comprising, as main components, polyester A having a moisture content of 100 ppm or less and polyester B having a moisture content of 0.05 to 0.6% by weight, wherein the polyester A has substantially the same composition as polyester B A polyester composition characterized in that the difference in intrinsic viscosity is in the range of 0.05 to 0.40 deciliter / gram and the moisture content is 10 to 700 ppm. A polyester composition comprising, as a main component, a polyester having ethylene terephthalate as a main repeating unit, wherein the polyester is the following polyester C and polyester D, and the difference in intrinsic viscosity between these is 0.05-0. A polyester composition characterized by having a moisture content of 10 to 700 ppm in a range of 40 deciliters / gram.
Polyester C: Intrinsic viscosity is 0.60 to 0.80 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 100 ppm or less, crystallization temperature measured by DSC is 140 to 180 ° C., and temperature is lowered Polyester having a crystallization temperature of 160 to 200 ° C.
Polyester D: Intrinsic viscosity is 0.70 to 1.00 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 0.05 to 0.6% by weight, and crystallization temperature when measured by DSC is 140. Polyester having a crystallization temperature of 160 to 200 ° C. at a temperature of ˜180 ° C. A polyester composition comprising, as a main component, a polyester having ethylene terephthalate as a main repeating unit, wherein the polyester is the following polyester E and polyester F, and the difference between these intrinsic viscosities is 0.05-0. A polyester composition characterized by having a moisture content of 10 to 700 ppm in a range of 40 deciliters / gram.
Polyester E: Intrinsic viscosity is 0.60 to 0.80 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 0.05 to 0.6% by weight, and crystallization temperature at the time of temperature rise measured by DSC is 140. Polyester having a crystallization temperature of 160 to 200 ° C. at a temperature of ˜180 ° C.
Polyester F: Intrinsic viscosity is 0.70 to 1.00 deciliter / gram, acetaldehyde content is 10 ppm or less, moisture content is 100 ppm or less, crystallization temperature when measured by DSC is 140 to 180 ° C., temperature is decreased Polyester having a crystallization temperature of 160 to 200 ° C. The polyester composition according to any one of claims 1 to 3, wherein the aldehyde content is 50 ppm or less. The polyester composition according to any one of claims 1 to 4, wherein the cyclic ester oligomer content is 70% or less of the cyclic ester oligomer content of the melt polycondensation polyester prepolymer. The polyester composition according to any one of claims 1 to 5, wherein an increase amount of the cyclic ester oligomer when melted at a temperature of 290 ° C for 60 minutes is 0.40% by weight or less. A polyester molded article obtained by melt-molding the polyester composition according to claim 1. The polyester molded body according to claim 7, wherein the polyester molded body is any one of a sheet-like material, a film, and a hollow molded body. A polyester molded article according to claim 7, wherein the polyester molded article is a coating melt-extruded on a substrate. The polyester composition according to claim 2 or the polyester composition according to claim 3, wherein the molten resin temperature in the molding machine is 240 to 305 ° C and the melt residence time in the molding machine is 5 to 500 seconds. A method for producing a polyester molded body, which is kneaded and molded by

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