JP2007138155A - Polyester composition, polyester molded product made of the same and method for manufacturing polyester blow molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester composition which inhibits production of aldehydes such as acetaldehyde or cyclic trimers at molding, is excellent in transparency and shows little change in transparency, and a method for manufacturing a polyester blow molded product. <P>SOLUTION: The polyester composition essentially comprises at least two polyesters each comprising ethylene terephthalate as a main repeating unit and comprising at least one metal compound chosen from Mg, Ca, Co, Mn and Zn compounds, a P compound and an Sb compound. The difference in limiting viscosity numbers between the two polyesters is within the range of 0.05-0.25 dL/g. The number of deposit particles of 1 μm or larger comprising a P atom and at least one metal atom chosen from the group consisting of a metallic Mg atom, a metallic Ca atom, a metallic Co atom, a metallic Mn atom and a metallic Zn atom and the difference in the number of the deposit particles between the polyesters are ≤5,000 particles/mm<SP>2</SP>and ≤1,000 particles/mm<SP>2</SP>, respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a hollow molded body such as a beverage bottle, a sheet-like article, a molded article such as a stretched film, and a coating coated on a substrate such as paper or film (hereinafter, these uses are referred to as “ Polyester composition that is suitably used as a raw material such as “molded product”), and in particular, generation of aldehydes such as acetaldehyde and cyclic trimer during molding is suppressed, and transparency is excellent and variation in transparency The present invention relates to a polyester composition that gives a molded product with a low content and a polyester molded product that is excellent in transparency and flavor retention. Moreover, this invention relates to the manufacturing method of the polyester hollow molded object which has the said characteristic.

As a material for containers, particularly 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. Among these, polyester, particularly polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is excellent in chemical properties, mechanical strength, heat resistance, transparency, and gas barrier properties. It is most suitable as a material for molded articles such as beverage filling containers such as soft drinks and carbonated drinks.
In general, PET used for such applications is produced mainly using terephthalic acid and ethylene glycol as raw materials, and using a germanium compound, an antimony compound, a titanium compound, and a mixture thereof as a polycondensation catalyst.

  Among the above catalysts, the antimony catalyst is used as a catalyst for producing PET for fibers and films because of its low price. However, it is very difficult to obtain a hollow molded article having a high crystallization speed and excellent transparency as compared with the case where a germanium compound or a titanium compound is used as a catalyst.

  In order to solve these problems, a germanium compound or a mixture of this and a titanium compound is used as a polycondensation catalyst. However, when an expensive germanium compound is used, there is a drawback that the cost of PET increases.

  As a method for solving such a problem, for example, a method in which transparency is improved by defining a use amount ratio of an antimony compound and a phosphorus compound (for example, see Patent Document 1) is disclosed. However, the transparency and crystallization speed of the hollow molded body obtained from this method are not stable, and the fluctuation is very large. Therefore, the transparency is not sufficient. However, there is a problem in that the size of the plug portion becomes unstable and a capping defect occurs.

  In addition, a method for producing a polyester having excellent transparency using an antimony compound, phosphoric acid and a sulfonic acid compound (see, for example, Patent Document 2), an antimony compound, a metal compound such as Mg, and a use amount and a use ratio of the phosphorus compound Polyesters that define the compounding amount of the basic nitrogen compound are disclosed (for example, see Patent Document 3), and it has been found that a molded product with improved transparency can be obtained from this polyester. However, it has been found that even when such a polyester is used, transparency and flavor (flavorability) are sometimes very poor, and only a hollow molded article having a low commercial value can be obtained.

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. 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 the AA content by solid-phase polymerization of melt-polycondensed polyester (see, for example, Patent Document 4), AA at the time of molding using a copolyester having a lower melting point A method of reducing the production (for example, see Patent Document 5), a method of 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 of the polyester resin (for example, , Patent Document 6), polyester containers made of a polyester composition containing thermoplastic polyamide and a specific polyamide whose terminal amino group concentration is regulated within a certain range (for example, see Patent Document 7), polyester prepolymer After conditioning the moisture content to 2000 ppm or more, crystallization and solid phase polymerization A method (for example, see Patent Document 8), a method in which polyester particles are treated with hot water at 50 to 200 ° C. and then heat-treated under reduced pressure or in an inert gas flow (for example, see Patent Document 9), during thermoforming There have been proposed a method for lowering the molding temperature as much as possible and a method for reducing the shear stress during thermoforming as much as possible. 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 satisfactory level, and the problem is unsolved, and a solution is awaited.
JP-A-6-279579 Japanese Patent Laid-Open No. 10-36495 JP 2000-129102 A JP-A-53-73288 Japanese Patent Laid-Open No. 57-16024 Japanese Examined Patent Publication No. 6-6661 Japanese Examined Patent Publication No. 4-71425 JP-A-2-298512 JP-A-8-120062

  The present invention solves the problems of the above-mentioned conventional methods, is a hollow molded article that is excellent in transparency, has little variation in transparency, and suppresses the formation of aldehydes such as acetaldehyde and cyclic trimers during molding. , Sheet-like products, stretched film, etc., polyester compositions that are suitably used as materials such as coatings on substrates, and hollow molded products with excellent heat-resistant dimensional stability, etc. It is an object of the present invention to provide a polyester composition that can be efficiently produced by high-speed molding while suppressing mold contamination, a polyester molded body comprising the same, and a method for producing a polyester molded body having the above-described properties.

In order to achieve the above object, the polyester composition of the present invention comprises at least one metal compound selected from Mg compound, Ca compound, Co compound, Mn compound and Zn compound, P compound and Sb compound, A polyester composition comprising as a main component two types of polyesters mainly composed of ethylene terephthalate, wherein the difference in intrinsic viscosity of the polyesters is in the range of 0.05 to 0.25 deciliter / gram. The number of precipitate particles of 1 μm or more consisting of at least one metal atom and P atom from Mg metal atom, Ca metal atom, Co metal atom, Mn metal atom and Zn metal atom contained in each polyester, and The difference in the number of precipitate particles is 5000 / mm ² or less and 1000 / mm ² or less, respectively. And

  The polyester composition of the present invention can be molded at a lower temperature because of improved flowability when melted in an extruder, and can reduce the content of aldehydes such as acetaldehyde and improve transparency. It becomes. At the same time, since the orientation during heating and stretching is improved, it is possible to give a stretched molded article having excellent mechanical properties such as elastic modulus and tensile strength and excellent heat fixability. It is usefully used as a stretched hollow container excellent in pressure.

  The difference in intrinsic viscosity of the polyester constituting the polyester composition of the present invention is preferably 0.06 to 0.23 deciliter / gram, more preferably 0.07 to 0.20 deciliter / gram, particularly preferably 0.10. ~ 0.18 deciliter / gram. When the above-mentioned intrinsic viscosity difference is less than 0.05 deciliter / gram, the content of aldehyde such as acetaldehyde in the obtained molded product cannot be reduced, and the flavor retention cannot be improved. On the other hand, when the above-mentioned intrinsic viscosity difference exceeds 0.25 deciliter / gram, thickness irregularities, whitened flow patterns, and the like occur 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.

  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 These are polyesters obtained by contact treatment with water under the condition that 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, at least two kinds of polyester constituting the polyester composition of the present invention do not include polyester hydrolyzed by a method such as heat treatment under pressure with water or polyester reduced by IV or melt treated to reduce IV. .

Further, the number of precipitate particles of 1 μm or more consisting of at least one metal atom and P atom from Mg metal atom, Ca metal atom, Co metal atom, Mn metal atom and Zn metal atom contained in each polyester, and The difference in the number of precipitate particles is preferably 4000 / mm ² or less and 700 / mm ² or less, respectively, more preferably 3000 / mm ² or less and 500 / mm ² or less, most preferably, ^They are 1000 pieces / mm ² or less and 300 pieces / mm ² or less, respectively. When the number of precipitate particles of 1 μm or more in each polyester exceeds 5000 / mm ² , the transparency of the hollow molded body from the obtained polyester composition, particularly the stretched hollow molded body and the stretched heat-fixed hollow molded body. Becomes very bad. Further, when the difference in the number of precipitate particles of 1 μm or more of each polyester used exceeds 1000 particles / mm ² , the crystallization speed of the preform is high, and the fluctuation thereof is large, and the transparency is stable and good. It becomes difficult to obtain a hollow molded body.

  In addition, it is preferable that the polyester which comprises the polyester composition of this invention is substantially the same composition. Here, “substantially the same” means that the acid component and the glycol component in each composition are 95 mol% or more, preferably 97 mol% or more, more preferably 98 mol%. The above is preferably the same.

In this case, when the crystallization temperature of the molded body obtained from each polyester is lowered and the difference between the crystallization temperatures when the temperature is lowered is 200 ° C. or less and less than 18 ° C., respectively, when the molded body is heated and crystallized. The number of spherulites produced and the difference between them can be 2 × 10 ^{9 to} 90 × 10 ⁹ pieces / m ² and less than 30 × 10 ⁹ pieces / m ² .

The crystallization temperature of the molded body obtained from each polyester during the temperature drop and the difference between the crystallization temperatures during the temperature drop are preferably 190 ° C. or less and less than 15 ° C., respectively, more preferably 180 ° C. or less, respectively. Less than 13 ° C., most preferably less than 175 ° C. and less than 10 ° C., respectively, and the number of spherulites generated when the shaped body is crystallized at elevated temperature and the difference between these spherulites are preferably 2 0.5 × 10 ⁹ to 80 × 10 ⁹ pieces / m ² and less than 25 × 10 ⁹ pieces / m ² , more preferably 2.7 × 10 ⁹ to 75 × 10 ⁹ pieces / m ² and 20 × 10, respectively. Less than ⁹ pieces / m ² , most preferably 3.0 × 10 ⁹ to 70 × 10 ⁹ pieces / m ² and less than 10 × 10 ⁹ pieces / m ² , respectively. When the crystallization temperature of the molded body obtained from each polyester exceeds 200 ° C., the transparency of the preforms obtained by injection molding is poor, and the crystallization temperature of these molded bodies when the temperature is lowered. When the difference in temperature is 18 ° C. or more, the transparency of the obtained preform is very poor, and the variation becomes large, which is a problem. Further, when the number of spherulites generated when the molded body is crystallized at elevated temperature exceeds 90 × 10 ⁹ pieces / m ² , a whitened flow pattern or the like is generated in the obtained stretched hollow molded body, and the transparency is increased. Worsens and becomes a problem. In order to produce a polyester having less than 2 × 10 ⁹ spherulites / m ² when crystallized at elevated temperature, it is necessary to limit the amount of antimony compound used as antimony atoms to less than 50 ppm, Economical production is not possible with such usage. Further, when the difference in the number of spherulites generated when crystallization is performed at a temperature of 30 × 10 ⁹ pieces / m ² or more, the crystallinity during heating of the preform is very high, and the stretched hollow molded body Transparency deteriorates.

  Here, the number of spherulites generated when temperature rising crystallization means the number of spherulites measured by the method described later.

  In this case, the acetaldehyde content may be 10 ppm or less, and the cyclic trimer content may be 0.70% by weight or less.

In this case, the polyester composition may contain, as main components, the following polyester A and polyester B having ethylene terephthalate as a main repeating unit.
Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.80 deciliter / gram, diethylene glycol component is 1.0 to 5.0 mol% of all glycol components, isophthalic acid component is 0 to 3.0 mol of all acid components %, The polyester whose crystallization temperature at the time of temperature rise is 140-180 degreeC.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.95 deciliter / gram, diethylene glycol component is 1.0 to 5.0 mol% of all glycol components, isophthalic acid component is 0 to 3.0 mol of all acid components %, The polyester whose crystallization temperature at the time of temperature rise is 140-180 degreeC.

  The polyester 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.

  Here, the crystallization temperature at the time of temperature rise and the crystallization temperature at the time of temperature fall of the polyester which comprises this invention are calculated | required by the DSC measuring method of a postscript about the molded board (2 mm thickness) which injection-molded these polyesters at 290 degreeC. Value.

  In this case, the polyester composition can be molded into a polyester molded body.

  Further, in this case, the elution amount of antimony atoms when the polyester stretched hollow molded article of the present invention comprising the above-described polyester composition is subjected to an elution test can be 2.0 ppb or less.

  Moreover, in this case, it can be a coating obtained by melt-extruding the polyester composition on a substrate.

  Furthermore, it is preferable to knead the above polyester composition and mold the hollow molded body under the conditions that the molten resin temperature in the molding machine is 260 to 305 ° C. and the melt residence time in the molding machine is 5 to 300 seconds.

  The polyester composition of the present invention has a flow characteristic improved so that the amount of aldehyde generated during molding is small, and when formed into a molded body, it can give a molded body excellent in mechanical properties such as pressure resistance. . In addition, since the flow characteristics of the polyester composition of the present invention are improved, it is possible to efficiently produce a molded body, particularly a hollow molded body, which has little distortion during molding and has excellent heat-resistant dimensional stability. Further, the polyester molded body of the present invention has very good pressure resistance and heat-resistant dimensional stability, and the method for producing a polyester hollow molded body of the present invention has a long-time continuous moldability that does not contaminate the mold. Excellent.

Hereinafter, embodiments of the polyester composition of the present invention will be specifically described.
That is, at least two kinds of polyester constituting the polyester composition of the present invention are each a linear polyester containing 90 mol% or more of ethylene terephthalate units, preferably 93 mol% or more, more preferably 95 mol% or more, Particularly preferred is a linear polyester containing 97 mol% or more.

  When the polyester is a copolymer, the dicarboxylic acids used for copolymerization of the polyester include isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyru 4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid, 4 , 4'-diphenylsulfone dicarboxylic acid, aromatic dicarboxylic acids such as 1,3-phenylene dioxydiacetic acid and functional derivatives thereof, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, Aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, glutaric acid, dimer acid and their functional derivatives, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid and cyclohexanedicarboxylic acid and their functions And the like.

  When the polyester is a copolymer, glycols used for copolymerization of the polyester include diethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, neopentyl. Glycol, 2-ethyl-2-butyl-1,3-propanediol, diethylene glycol, polyethylene glycol, polytetramethylene ether glycol and other aliphatic glycols, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1 -Cyclohexane dimethylol, 1,4-cyclohexane dimethylol, alicyclic glycols such as 2,5-norbornane dimethylol, bisphenol A, bisphenol A And aromatic glycols such as alkylene oxide adducts.

  In addition, when the polyester contains other copolymer component composed of a polyfunctional compound, examples of the acidic component thereof include trimellitic acid and pyromellitic acid, and examples of the glycol component include glycerin and pentaerythritol. Can do. The amount of the above copolymerization component used must be such that the polyester remains substantially linear. Monofunctional compounds such as benzoic acid and naphthoic acid may be copolymerized.

  At least two kinds of polyesters constituting the polyester composition of 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 step or may be performed in multiple steps. 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 will be described, but the present invention is not limited thereto. That is, direct esterification is performed by directly reacting terephthalic acid with ethylene glycol and, if necessary, other copolymerization components to distill off water and esterify, and then polycondensate under reduced pressure in the presence of an antimony compound as a polycondensation catalyst. Manufactured by the law. Next, when the intrinsic viscosity is increased or the low acetaldehyde content or the low cyclic trimer content is set as in a heat-resistant container for low flavor beverages, the melt polycondensation obtained in this way is performed. The polyester is subsequently solid state polymerized.

  First, when a low polymer is produced by an esterification reaction, 1.02 to 2.0 mol, preferably 1.03 to 1.6 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.

  The starting material, terephthalic acid or ethylene glycol, includes virgin dimethyl terephthalate derived from para-xylene, ethylene glycol derived from terephthalic acid or ethylene, as well as methanol decomposition and ethylene glycol from used PET bottles. Recovered raw materials such as dimethyl terephthalate, terephthalic acid, bishydroxyethyl terephthalate or ethylene glycol recovered by a chemical recycling method such as decomposition 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 Mg compound, Ca compound, Co compound, Mn compound, and Zn compound used in the production of at least two kinds of polyesters constituting the polyester composition of the present invention can all be used as long as they are soluble in the reaction system.

  Examples of Mg compounds include lower fatty acid salts such as magnesium hydride, magnesium oxide, and magnesium acetate, alkoxides such as magnesium methoxide, and the like.

  Examples of the Ca compound include lower fatty acid salts such as calcium hydride, calcium hydroxide, and calcium acetate, and alkoxides such as calcium methoxide.

  Examples of the Co compound include lower fatty acid salts such as cobalt acetate, organic acid salts such as cobalt naphthenate and cobalt benzoate, chlorides such as cobalt chloride, and cobalt acetylacetonate.

  Examples of the Mn compound include organic acid salts such as manganese acetate and manganese benzoate, chlorides such as manganese chloride, alkoxides such as manganese methoxide, manganese acetylacetonate, and the like.

  Examples of the Zn compound include organic acid salts such as zinc acetate and zinc benzoate, chlorides such as zinc chloride, alkoxides such as zinc methoxide, and zinc acetylacetonate.

  When adding the Mg compound, Ca compound, Co compound, Mn compound and Zn compound used in the present invention to the polyester production process, the esterification rate is 50% or more when the polyester is produced by the direct esterification method. It is preferable to add. If the esterification rate is less than 50%, the transparency of the resulting hollow molded article becomes very poor.

  Further, the Mg compound, Ca compound, Co compound, Mn compound, and Zn compound used in the present invention are in the range of 0.1 to 2.8 mol as metal atoms contained in 1 ton of the finally obtained polyester. It is added so that the content is reached. Preferably it is 0.15-2.0 mol, More preferably, it is the range of 0.2-1.0 mol.

  These metal compounds have an effect of promoting the polymerization rate and an effect of improving the color tone of the polyester, but if the above upper limit is exceeded, the color tone and by-products such as acetaldehyde, and the transparency of the obtained hollow molded body Adversely affects.

  Examples of the P compound used in the present invention include phosphoric acid, phosphorous acid, phosphonic acid, and derivatives thereof. 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 dimethyl ester, phenylphosphonic acid diethyl ester, phenyl -Luphosphonic acid diphenyl ester, ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, methyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,5- 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, etc., which may be used alone or in combination of two or more.

The P compound used in the present invention is preferably added in divided portions at least twice during the production process of the polyester. By adding the P compound in two or more portions, it becomes possible to reduce the number of precipitate particles composed of the metal atoms and P atoms to 5000 particles / mm ² or less. Transparency can be improved.

  The method of adding the P compound in a divided manner can be carried out by shifting the addition time when the polyester is produced batchwise, or by changing the addition location when the polyester is produced continuously. When the polyester is produced continuously, a method of increasing the number of reaction cans and adding them separately to at least two reaction cans, and separately adding at least two addition positions in the same reaction can in the order of progress of the reaction. Various methods such as a method of providing and adding, and a method of line mixing in a continuous portion of the reaction vessel and the reaction vessel are employed.

  As for the division ratio of the addition amount of the P compound, the initial addition amount is preferably about 50% or less, and particularly preferably 30% or less of the total addition amount.

  Regarding the addition time of the P compound, the first addition time is not particularly limited, and the second and subsequent additions are preferably added after the addition of the Mg compound, Ca compound, Co compound, Mn compound and Zn compound. The first P compound may be added before or during the esterification, or may be added after the completion of the esterification, but it is preferably added after the completion of the esterification after the second time.

  Further, the P compound used in the present invention is added so that the molar ratio M / P of metal atoms and P atoms contained in 1 ton of the finally obtained polyester is in the range of 0.1 to 2. . Preferably it is 0.2-1.5, More preferably, it is the range of 0.3-1.3. When the M / P is less than 0.1, the transparency of the obtained hollow molded article is deteriorated, and when the M / P exceeds 2, the hue of the polyester is deteriorated.

  Examples of the Sb compound used in the present invention include antimony trioxide, antimony acetate, antimony tartrate, antimony tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, and triphenylantimony.

  Moreover, Sb compound is added so that it may become content of 0.4-2.9 mol as Sb atom contained in 1 ton of polyester finally obtained. Preferably it is 2.5 mol or less, More preferably, it is 2.1 mol or less. If it is less than 0.4 mol per ton of polymer, the polycondensation time becomes very long, which is a problem from the viewpoint of economical productivity. Moreover, when it exceeds 2.9 mol, the transparency of the obtained hollow molded object falls, or a color tone worsens and it becomes a problem. The addition of these Sb compounds can be carried out at any stage of the polyester production.

  Further, the at least two kinds of polyesters constituting the polyester composition of the present invention may further contain other metal compounds such as compounds of titanium, germanium, tin, zirconium, lead and the like, if desired. The content of these metal compounds with respect to the polyester is preferably 0.1 to 50 ppm.

After the melt polycondensation polyester is obtained, the melt polycondensation polyester obtained as described above is extruded from the pores into at least one of the following (1) to (4), and more preferably into cooling water satisfying all. It is preferable that chips are formed into a columnar shape, a spherical shape, a square shape, or a plate shape by a method of cutting with a cooling method, or a method of cutting while cooling with cooling water having the same water quality as described above after being extruded in the atmosphere. .
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.

  When solid-state polymerization is performed on the polyester that has been chipped while cooling with cooling water that does not satisfy the above-described conditions, foreign matters in the molded body of the polyester obtained under such conditions are caused by impurities in the cooling water. There is also a problem that the product value increases and the flavor value deteriorates and the commercial value is lowered.

  The shape of the at least two kinds of polyester chips constituting 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 diameter is usually 1.0 to 4.0 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. .

  Moreover, the ratio of the average weight (W) of the polyester which comprises the polyester composition of this invention is 1.00-1.30, Preferably it is 1.00-1.28, More preferably, it is 1.00-1.25. 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 A and the polyester B is likely to occur, which causes the transparency and thickness unevenness of the stretched hollow polyester body, which is not preferable.

  Further, the difference in crystallinity of the polyester chips constituting the polyester composition of the present invention is 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 acetaldehyde content is lost, and the blended amount of the polyester tends to occur, which is not preferable because it causes the transparency of the polyester unstretched molded body and the stretched hollow molded body and fluctuations in the acetaldehyde content. . 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.

As a method of setting the number of spherulites to be generated in the range of 2 × 10 ^{9 to} 90 × 10 ⁹ pieces / m ² when the molded body obtained from the polyester constituting the polyester composition of the present invention is subjected to temperature crystallization, Satisfy the following conditions 1) to 3),
1) The content (M) of at least one metal atom from Mg atom, Ca atom, Co atom, Mn atom and Zn atom contained in 1 ton of polyester is 0.1 to 2.8 mol.
2) The addition method of P compound is a divided addition method.
3) The molar ratio M / P of the metal atom content (M) such as Mg and the P atom content (P) is in the range of 0.1-2.
Furthermore, it can be achieved by adopting at least one of the following methods. Needless to say, it is most preferable to employ all the following methods.
4) The content of Sb atoms contained in 1 ton of polyester is 0.4 to 2.9 mol.
5) Cooling water that satisfies all of the above (1) to (4) is used as cooling water at the time of chip formation.
6) Set the crystallinity of the chip to 65% or less.
7) The polyester fine content is in the range of 0.1 to 500 ppm.

  Examples of the method for bringing the fine content into the above range include a method of treating the obtained polyester with a vibrating sieve, a method of washing with water, and a method of treating with a wind separator.

  Further, when the number of spherulites is less than the above lower limit, a method of giving an impact to the obtained polyester chip, a polyolefin resin, particularly polyethylene, polyamide resin, polyoxymethylene resin, etc. are blended as described below. A polyester having the number of spherulites within the scope of the claims can also be obtained by a method or the like.

  The acetaldehyde content of the polyester composition of the present invention is desirably 10 ppm or less, preferably 5 ppm or less, more preferably 4 ppm or less. When the acetaldehyde content exceeds 10 ppm, the effect of flavor retention of the content of the polyester molded body from this polyester composition is deteriorated. Further, these lower limits are preferably 0.1 ppb from the viewpoint of production.

The content of the cyclic trimer of the polyester composition of the present invention 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. The following is preferable. The lower limit of the cyclic trimer content is 0.20% by weight or more, preferably 0.22% by weight or more, and more preferably 0.25% by weight or more from the viewpoint of economical production. When the content of the cyclic trimer exceeds 0.70% by weight, low-molecular substances such as the sublimated cyclic trimer are frequently clogged in the vent portion of the injection molding machine, and stable production cannot be performed. The problem that occurs.
Moreover, when shape | molding a heat resistant hollow molded object etc. from the polyester composition of this invention, although heat processing is performed within a heating metal mold | die, content of cyclic trimer exceeds 0.70 weight%, and contains it. In such a case, the adhesion of the oligomer to the surface of the heating mold increases rapidly, and the transparency of the obtained hollow molded article is very deteriorated.

  Moreover, it is preferable that the polyester composition of this invention contains the following polyester A and polyester B which have ethylene terephthalate as the main repeating unit as a main component.

Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.80 deciliter / gram, diethylene glycol component is 1.0 to 5.0 mol% of all glycol components, isophthalic acid component is 0 to 3.0 mol of all acid components %, The crystallization temperature at the time of temperature rise is 140-180 degreeC.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.95 deciliter / gram, diethylene glycol component is 1.0 to 5.0 mol% of all glycol components, isophthalic acid component is 0 to 3.0 mol of all acid components %, The crystallization temperature at the time of temperature rise is 140-180 degreeC.

  Moreover, as polyester A or polyester B, it is possible to use at least one kind of each polyester that falls within the above characteristic range. For example, as polyester A, two kinds of polyesters that differ only in IV are used. It is also possible to use polyester mixed using one kind of polyester so as to have the above-mentioned constitution ratio.

The intrinsic viscosity IV _A of polyester A is preferably 0.62 to 0.78 deciliter / gram, more preferably 0.65 to 0.75 deciliter / gram, and the acetaldehyde content is preferably 8 ppm or less, more preferably 5 ppm or less, Moreover, the crystallization temperature at the time of temperature rise becomes like this. Preferably it is 143-175 degreeC, More preferably, it is 145-170 degreeC. If the intrinsic viscosity IV _A of the polyester A is less than 0.60 dl / g is a problem deteriorates the transparency of the resulting molded product. On the other hand, when it exceeds 0.80 deciliter / gram, the effect of reducing acetaldehyde is lowered. Further, when the crystallization temperature at the time of raising the temperature of the polyester A is less than 140 ° C., the transparency of the molded product is deteriorated, and when it exceeds 180 ° C., the effect of improving the crystallization rate of the plug portion is deteriorated.

The intrinsic viscosity IV _B of polyester B is preferably 0.74 to 0.90 deciliter / gram, more preferably 0.75 to 0.85 deciliter / gram, and the acetaldehyde content is preferably 8 ppm or less, more preferably 5 ppm or less, Moreover, the crystallization temperature at the time of temperature rise becomes like this. Preferably it is 143-175 degreeC, More preferably, it is 145-170 degreeC. The intrinsic viscosity of the polyester B IV _B If there is less than 0.73 dl / g is a problem deteriorates the transparency of the resulting molded product. On the other hand, if it exceeds 0.95 deciliter / gram, the heat generation during molding becomes intense and the reduction effect of acetaldehyde becomes low. Further, when the crystallization temperature of polyester B at the time of temperature rise 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.

  The content of diethylene glycol (hereinafter sometimes abbreviated as DEG) copolymerized with the polyester used in the present invention is preferably 1.3 to 4.5 with respect to the total glycol component constituting the polyester. It is mol%, More preferably, it is 1.5-4.0 mol%, Most preferably, it is 1.8-3.0 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.

  In addition, the amount of isophthalic acid copolymerized with the polyester used in the present invention is preferably 0 to 2.0 mol%, more preferably 0 to 1.5 mol%, based on the total acid components constituting the polyester. Most preferably, it is 0-1.0 mol%. When the amount of isophthalic acid exceeds 3.0 mol%, the heat resistance and stretching properties are deteriorated, which causes a problem.

  By using the polyester composition of the present invention having the above properties, molding at a lower temperature is possible, the content of aldehydes such as acetaldehyde is low, the flavor retention is excellent, the transparency is excellent, and the transparent spots. It is possible to obtain a hollow molded body that is free from the occurrence of a whitened flow pattern or a partially whitened or wrinkled product generated in the molded body. In particular, these effects become remarkable in the case of a thick stretched molded body such as a bottle.

  Moreover, the stretched hollow molded body obtained by stretching an unstretched hollow molded body obtained by melt molding under the conditions regulated by the present invention using the polyester composition of the present invention under the conditions described in the following measurement section. The elution amount of antimony atoms in the elution test can be reduced to preferably 1.8 ppb or less, more preferably 1.5 ppb or less, and most preferably 1.0 ppb or less.

  Furthermore, it is preferable that the polyester composition of the present invention contains 0.1 ppb to 50000 ppm of at least one resin selected from the group consisting of polyolefin resins, polyamide resins, and polyacetal resins. The blending ratio of the resin used in the present invention to the polyester 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. 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, it becomes a problem of capping failure. On the other hand, if it exceeds 50000 ppm, the crystallization speed becomes high, and the crystallization of the plug portion of the hollow molded body becomes excessive, and the shrinkage amount of the plug portion does not fall within the specified value range, resulting in capping failure and the content. Leakage, and the preform for the hollow molded body 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 of directly adding the resin such as the polyolefin resin to the polyester so that the content is in the above range, and melt-kneading, or In addition to conventional methods such as a method of adding as a master batch and melt-kneading, the resin is added to the polyester production stage, for example, during melt polycondensation, immediately after melt polycondensation, immediately after precrystallization, during solid phase polymerization, In any stage such as immediately after the phase polymerization, 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 the polyester chips can be added under flow conditions. It is also possible to use a method such as bringing the resin member into contact with the resin member or a method of melt-kneading after the contact treatment.

  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, the polyester composition of the present invention can be blended with polyamide, polyesteramide, a low molecular weight amino group-containing compound, or a hydroxyl group-containing compound as an aldehyde compound trapping material.

  When the polyester molded body from the polyester composition of the present invention is used as a container for low flavor beverages such as mineral water, the acetaldehyde content and formaldehyde content of the polyester molded body are 10 ppm or less and 3 ppm or less, respectively. Preferably they are 8 ppm or less and 2 ppm or less, More preferably, they are 7 ppm or less and 1 ppm or less.

  The polyester molded body having a low aldehyde content such as acetaldehyde is, for example, 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, more preferably 100 parts by weight of the polyester composition. It can be obtained by using a polyester composition in which 1.0 to 2 parts by weight of a capture material for an aldehyde compound such as polyamide is blended.

  Examples of the polyamide to be blended in the polyester composition of the present invention as an aldehyde compound capturing material include at least one polyamide selected from aliphatic polyamide and partially aromatic polyamide.

  Specific examples of the aliphatic polyamide include nylon 6, nylon 11, nylon 12, nylon 66, nylon 69, nylon 610, nylon 6/66, nylon 6/610, and the like.

  Preferred examples of the partially aromatic polyamide according to the present invention are derived from metaxylylenediamine or mixed xylylenediamine containing metaxylylenediamine and 30% or less of the total amount of paraxylylenediamine and an aliphatic dicarboxylic acid. A metaxylylene group-containing polyamide containing at least 20 mol% or more, more preferably 30 mol% or more, particularly preferably 40 mol% or more in the molecular chain.

  Further, the partially aromatic polyamide according to the present invention contains structural units derived from a polybasic carboxylic acid having 3 or more bases such as trimellitic acid and pyromellitic acid within a substantially linear range. Also good.

  Examples of these polyamides include homopolymers such as polymetaxylylene adipamide, polymetaxylylene sebacamide, polymetaxylylene speramide, and metaxylylenediamine / adipic acid / isophthalic acid copolymers, metaxylylene. / Paraxylylene adipamide copolymer, metaxylylene / paraxylylene piperamide copolymer, metaxylylene / paraxylylene azelamide copolymer, metaxylylenediamine / adipic acid / isophthalic acid / ε-caprolactam copolymer And metaxylylenediamine / adipic acid / isophthalic acid / ω-aminocaproic acid copolymer.

  As another preferred example of the partially aromatic polyamide according to the present invention, a structural unit derived from an aliphatic diamine and at least one acid selected from terephthalic acid or isophthalic acid is at least 20 in the molecular chain. Polyamide containing at least mol%, more preferably at least 30 mol%, particularly preferably at least 40 mol%.

  Examples of these polyamides include polyhexamethylene terephthalamide, polyhexamethylene isophthalamide, hexamethylene diamine / terephthalic acid / isophthalic acid copolymer, polynonamethylene terephthalamide, polynonamethylene isophthalamide, nonamethylene diamine / terephthalic acid. / Isophthalic acid copolymer, nonamethylenediamine / terephthalic acid / adipic acid copolymer, and the like.

  Polyester amides include polyester amide produced from terephthalic acid, 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.

  Moreover, it is preferable that the polyamide and polyesteramide which concern on this invention are 50-120 degreeC in the secondary transition point measured by DSC (differential scanning calorimeter). When the secondary transition point is less than 50 ° C., it is not preferable because it is fused at the time of drying process or extrusion with polyester or cannot be quantitatively extruded. Moreover, when exceeding 120 degreeC, when extending | stretching a polyester composition, it will not be stretched | uniformly uniformly but a thickness spot etc. will arise and it is unpreferable.

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, and 4,4′-diaminodiphenylmethane. And aromatic amine compounds such as melamine, triazine compounds such as 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.

  As a method for blending the aldehyde compound capture material, various methods described above for the blending method of the polyolefin resin or the like blended for the purpose of improving crystallinity can be used.

  The polyester composition of the present invention is preliminarily prepared by using a commonly used injection molding method after the moisture content is reduced to about 100 ppm or less, preferably 50 ppm or less by heat drying under reduced pressure or heat drying under an inert gas. A molded body can be molded. As conditions relating to the production of the preform, the molten resin temperature is 260 to 305 ° C., preferably 262 to 295 ° C., more preferably 265 by heating a barrel, a die, a hot runner or the like of an injection molding machine or an extrusion molding machine. It is important to set the temperature in a range of ˜285 ° C. Here, the molten resin temperature refers to a temperature obtained by immediately measuring, for example, a thermocouple thermometer with a resin injected or extruded from a nozzle tip or a die outlet of an injection molding machine or the like.

  In addition, 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, or in the case of injection molding. The cycle time, the metering stroke (screw back amount) and the like are arbitrarily set, and the time is set in the range of 5 to 300 seconds, preferably 10 to 200 seconds, more preferably 20 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 case of injection molding, if the melt residence time is t, t is given by the following formula (5).

    t = W × S / P (5)

Here, W: Weight of molten resin (g) in a cylinder and hot runner of an injection molding machine, etc.
S: Molding cycle time (seconds)
P: Molded product weight (g)

  In the present invention, by controlling the molten resin temperature in the range of 260 to 305 ° C. and setting the melt residence time in the range of 5 to 300 seconds, at least two kinds of polyesters mainly composed of ethylene terephthalate are the main repeating units. From a polyester composition containing as a main component, the content of aldehydes such as acetaldehyde is low, the flavor retention is excellent, the transparency is excellent, and the transparent spots (for example, the whitened flow pattern or It is possible to obtain a preform for a hollow molded body that is free from the occurrence of partial whitening or cocoon and has no problem with the shape of the plug after crystallization. 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 260 ° C., the torque load of the injection molding machine is large and molding becomes difficult, and the obtained preform has extremely poor 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. When the melt residence time is less than 5 seconds, the transparency of the preform is deteriorated due to insufficient melting, and when it exceeds 300 seconds, the transparency of the preform is very good. As a result, the molding cycle becomes longer and the productivity of the preform is lowered.

  Here, the polyester composition containing as a main component a polyester having ethylene terephthalate as the main repeating unit has been described. However, the molten resin temperature when producing a preform from the polyester composition of the present invention is higher than the melting point of the polyester constituting the polyester composition. In addition, it is necessary to control the set temperature of a barrel of an injection molding machine or the like or a hot runner so as to be 10 to 45 ° C., preferably 10 to 40 ° C., more preferably 30 ° C.

  Here, the polyester preform is a preform obtained by compression molding a molten mass obtained by melt extrusion molding, a preform obtained by injection molding, or the like.

  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.

  The heat-set stretched hollow molded article obtained by molding as described above using the polyester composition of the present invention is an elution of antimony atoms when an elution test is performed under the conditions described in the following measurement method section. The amount can be reduced to 2.0 ppb or less, preferably 1.5 ppb or less, more preferably 1.0 ppb or less.

  The polyester composition of the present invention can also be used as at least one polyester composition constituting a multilayer hollow molded article.

Another application of the polyester composition of the present invention is a film that is 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.

  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 may be blended.

  In addition, when the polyester composition of the present invention is used for a film, in order to improve handling properties such as slipping property, winding property, and blocking resistance, calcium carbonate, magnesium carbonate, barium carbonate, sulfuric acid are included in the polyester. Inorganic particles such as calcium, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, organic salt particles such as calcium oxalate, calcium, barium, zinc, manganese, magnesium, terephthalate, divinylbenzene, styrene, acrylic acid, Inactive particles such as crosslinked polymer particles such as methacrylic acid, acrylic acid, or a vinyl monomer of methacrylic acid, alone or as a copolymer 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) Polyester cyclic trimer content (hereinafter referred to as “CT content”)
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, the volume was adjusted to 10 mL with dimethylformamide, and the cyclic trimer was quantified by high performance liquid chromatography.

(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. In the case of a chip, the sample is used as it is, and the hollow molded body is a sample collected to a size of about 2 mm from the plug portion. Further, the variation value of the acetaldehyde content of the hollow molded body was measured for 10 pieces, and the difference between the maximum value and the minimum value was obtained.

(6) Measurement of Fine Content About 0.5 kg of resin, sieve (A) with a mesh size of 5.6 mm according to JIS-Z8801, and sieve with 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 operation of washing and drying with ion-exchanged water was 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.

(7) Precipitate particle count 20 mg of resin was sandwiched between two cover glasses, melt-pressed at 280 ° C., cooled, and observed with a phase-contrast microscope, and image analysis processing apparatus LUZEX IID (Nippon Regulation) (Manufactured by Tar Co.), and deposits having a maximum particle length of 1 μm or more in the image are counted. The number of precipitate particles is converted per 1 mm ² area.

  Further, 10 g of the polyester resin is dissolved in 100 ml of p-chlorophenol / tetrachloroethane (weight ratio 3/1) at 120 ° C. This solution was filtered through a 0.1 μm membrane filter, washed with chloroform and acetone, and then the precipitates were confirmed with a scanning electron microscope (manufactured by Hitachi, Ltd.). It is determined that all of the precipitates are precipitates from the metal atoms and P atoms.

(8) 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 supplied by Shimadzu Corporation. Measurement was performed with an inductively coupled plasma emission spectrometer.

(9) 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) manufactured by Seiko Denshi Kogyo Co., Ltd., RDC-220. Using 10 mg of sample from the center of a 2 mm thick plate of the molded plate of (12) below. In the case of a preform, a sample was taken from the trunk.
The temperature was raised at a rate 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).

(10) Haze (degree of haze) and haze spots (%)
A sample was cut out from a 5 mm plate (D portion in FIG. 1) of the stepped molded plate of the following (12) and measured with a Nippon Denshoku haze meter, model NDH2000.
Moreover, the haze of the molded object shape | molded 10 times continuously was measured, and the haze spot was calculated | required by the following.
Haze spots (%) = maximum haze value (%)-minimum haze value (%)

(11) Number of spherulites at the time of temperature-crystallization of the molded body A test piece having a size of 8 mm × 10 mm was cut out from a plate portion having a thickness of 3 mm from the stepped molded plate of the following (12) to obtain a measurement sample. The molded plate has molecular orientation derived from the flow during molding, but the orientation state varies depending on the portion of the molded plate. Therefore, the alignment is performed by observing the intensity distribution of the light transmitted through the forming plate when the forming plate is sandwiched between two polarizing plates having the polarization planes orthogonal to each other and irradiated with visible light from a direction perpendicular to the polarizing plate surface. Checked the condition. A test piece was cut out from a portion that did not contain non-uniform molecular orientation (degree of orientation, fluctuation in orientation direction, etc.) within the above dimensions. At that time, the orientation of the optical anisotropy is confirmed in advance, and the relationship with the orientation of the cut specimen is as follows. The orientation of the optical anisotropy was determined by a method described in “New Polymer Experiment 6 Structure of Polymer (2)” (Kyoritsu Publishing Co., Ltd.) using a polarizing microscope and a sensitive color detection plate. It cut out so that the direction of an axis | shaft with a small refractive index (axis | shaft with a quick light speed) and the major axis of a test piece may become parallel. The alignment disorder introduced when the test piece is cut out and the unevenness of the cut surface significantly affect the measurement results. Then, the unevenness | corrugation of the cut surface and the site | part with disordered orientation were deleted using the cutter, and the flat surface was obtained. The density of the specimen and the degree of molecular orientation also affect the results. The density and birefringence values should be 1.3345 to 1.3355 g / cm ³ and 1.30 × 10 ^{−4 to} 1.50 × 10 ⁻⁴ , respectively. The density was measured using a water-based density gradient tube using a resin sampled from the vicinity of the specimen collection site as a sample. Birefringence was measured by the Belek Compensator method using a polarizing microscope (ECLIPSE E600 POL manufactured by Nikon Corporation). The measured value was a value obtained at the center of the test piece. The test piece prepared as described above was heat-treated with a thermo-mechanical analysis (TMA) manufactured by Mac Science, type TMA 4000S. The temperature was raised from room temperature to 210 ° C. at a rate of 27 ° C./min under a constant compression load of 0.2 g, maintained at 210 ° C. for 180 seconds, and then lowered to room temperature at a rate of 47 ° C./min. The number of spherulites is measured by the method.

  Using a microtome RM2065 manufactured by Leica, a section having a thickness of 2 μm is prepared from the end of the test piece. The section is observed using a polarizing microscope ECLIPSE E600POL manufactured by Nikon Corporation. Observation uses halogen lamp light as the light source, and monochromatization by an interference filter or the like is not performed. The optical system is adjusted to a so-called crossed Nicol state in which the optical axes of the polarizer and the analyzer are orthogonal to each other, and a sensitive color detection plate of 530 nm is inserted into the optical path. The image is observed with a color CCD camera (HV-C205, manufactured by Hitachi, Ltd.) connected to a polarizing microscope and stored as a still image on a Macintosh computer via an image capture board.

  When the slice is observed with the optical system as described above, a large number of spherulites are observed. When a 530 nm sensitive color test plate is inserted into the optical path and observed, the spherulites show the objectivity reflecting the orientation of the optical anisotropy inside. Specifically, the spherulites are observed as if they were divided into four with their centers symmetrical. The sensitive color detection plate exhibits different colors in the parallel direction and the vertical direction with respect to the low refractive index axis (parallel to the insertion direction). This color is the interference color when the retardation generated by the test plate increases depending on the sample and vice versa, and the interference color corresponding to the decrease when the retardation is reduced. It depends on the relationship of the anisotropic orientation.

  Using a CCD camera, photograph a 105μm x 79μm area on the sample and store it on a computer recording device (such as a hard disk or magneto-optical disk). From this image, the number of spherulites is measured in the following procedure using image processing software Ultimage / Pro (Image and Measurement) on a Macintosh computer. As described above, spherulites have two kinds of colors. Threshold level is set so that only one of these colors remains, and binarization is performed. By this operation, only a portion having one color is to be measured. In addition, execute Erosion in the Primary Morphology menu with Number of integrations = 1. By this operation, the connected portions are separated although they are regions belonging to different spherulites. After executing this operation, execute the Particle menu and read the value of Detected particles. At this time, particles with an area of 4 pixels or less are not measured. Since two particles are measured per spherulite, the value obtained by dividing the value of Detected particles read earlier by 2 is the number of spherulites.

(12) Molding of stepped molding plate Polyester that has been dried under reduced pressure at 140 ° C. and 0.1 mmHg or less for about 16 hours using a reduced pressure dryer is illustrated with an injection molding machine M-150C-DM type injection molding machine manufactured by Meiki Seisakusho. 1, 2 mm to 11 mm having a gate part (G) as shown in FIG. 2 (A part thickness = 2 mm, B part thickness = 3 mm, C part thickness = 4 mm, D part thickness = 5 mm, E part) The stepped molded plate having a thickness of 10 mm and a thickness of F part = 11 mm was injection molded.

Polyester previously dried under reduced pressure using a vacuum dryer DP61 manufactured by Yamato Scientific Co., Ltd. was used, and a dry inert gas (nitrogen gas) purge was performed in the molding material hopper to prevent moisture absorption during molding. The plasticizing conditions of the M-150C-DM injection molding machine are as follows: feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, cylinder temperature 45 ° C., 250 ° C. from the bottom of the hopper in order, nozzle The temperature was set at 290 ° C. The injection conditions were such that the injection speed and pressure holding speed were 20%, and the injection pressure and pressure holding were adjusted so that the weight of the molded product was 146 ± 0.2 g. Adjusted to 5 MPa lower.
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 entire cycle time including the molded product take-out time 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 test plate for evaluating the characteristics of the molded product was arbitrarily selected from stable molded products after the 10th shot from the start of molding after introducing the molding material and replacing the resin.

The molding temperature refers to the set temperature of the barrel including the nozzle.
A 2 mm-thick plate (part A in FIG. 1) is used for crystallization temperature (Tc1) during temperature rise, a crystallization temperature (Tc2) during temperature drop, and a 5 mm plate (part D in FIG. 1) is used for haze measurement.

  For measurement of haze and haze spots on the molded plate, a molded plate obtained by setting the location of the cylinder temperature of 290 ° C. to 280 ° C. was used.

(13) Molding of preformed body and hollow molded body In the same way as in (12), polyester was dried in advance using a vacuum dryer DP61 type manufactured by Yamato Scientific Co., Ltd., and molded to prevent moisture absorption during molding. The material hopper was purged with a dry inert gas (nitrogen gas). The temperature of the cylinder and the hot runner was set so that the resin temperature would be 280 ° C. by using M-150C-DM injection molding machine manufactured by each machine manufacturer, and the molding cycle was 50 seconds, the injection pressure was 1.8 to 2.3 kg / cm. ^{2. A} preform (outer diameter 29.4 mm, length 145.5 mm, wall thickness about 3.7 mm, weight 60 g) was molded at a back pressure of 0.5 Mp, a screw rotation speed of 120 rpm, and a feed screw rotation speed of 84 rpm. The melt residence time of the resin was about 110 seconds. The surface temperature of the mold when molding is stable is around 22 ° C.

  The plug parts of these preforms were heat-treated for 180 seconds with a homemade infrared heater, and then a mold pin was inserted to heat-crystallize the plug part. Next, this preform was biaxially stretched and blown with a LB-01E molding machine manufactured by CORPOPLAST, and then heat-set in a mold set at about 150 ° C. for about 5 seconds to form a container having a capacity of 1500 cc. The stretching temperature was controlled at 100 ° C.

In Example 2 and Comparative Example 5 using polyester 4, polyester 5, and polyester 7 copolymerized with isophthalic acid, the plug portion of the preform was not subjected to crystallization treatment, and heat setting after stretching was also possible. Did not do.
The molten resin temperature was measured by bringing a thermocouple thermometer into contact with the molten resin injected from the nozzle tip of the injection molding machine.

(14) Shape and size of the plug portion of the preform for the hollow molded body The shape and size of the plug portion crystallized in (13) were visually observed and evaluated as follows.
A: Extremely stable dimensional accuracy was obtained.
○: Stable dimensional accuracy was obtained.
X: Insufficient crystallization, poor shape, or excessive crystallization, poor dimensionality.

(15) Appearance of Hollow Molded Body Twenty hollow molded bodies from the tenth molding start of (13) were visually observed and evaluated as follows.
◎: Transparent and no appearance problem △: There is a little whitened flow pattern or whitened product in the hollow molded body ×: Whitened flow pattern or whitened product in the hollow molded body

(16) Amount of elution of antimony atoms (ppb)
The section cut from the body of the stretched polyester hollow molded body obtained in (13) is immersed in hot water at 95 ° C. for 60 minutes so as to obtain a bath ratio of ² ml per 1 cm ² of surface area, and then extracted into water. Antimony was measured by flameless atomic absorption method (measurement wavelength: 217.6 nm) as the concentration of dissolved antimony atom in water.

(Polyester 1 (Pes1))
As an esterification apparatus, the first esterification reaction apparatus provided with a stirrer, a partial condenser, a raw material charging port and a product take-out port, the inside of the reaction can is divided into two tanks, and a stirrer is attached to each reaction tank. A three-stage complete mixing tank type continuous esterification reaction apparatus comprising a second esterification reaction apparatus provided with a partial condenser, a raw material charging port and a product take-out port was used. An EG slurry of TPA adjusted to a molar ratio of EG to TPA of 1.8 is continuously supplied to the system containing the reaction product in the first esterification reactor, and an average residence time of 4 at normal pressure. The reaction was carried out at a temperature of 255 ° C. for a time.

  This reaction product was continuously taken out of the system, supplied to the first tank of the second esterification reaction apparatus, and continuously taken out from the second tank. The overflow method was adopted for the transfer from the first tank to the second tank.

  EG solution of magnesium acetate tetrahydrate in an amount of 0.82 mol (about 20 ppm with respect to the produced polyester resin) as Mg atoms per ton of the produced polyester resin from the supply port on the inlet side of the first tank; EG solution of phosphoric acid in an amount of 0.16 mol (about 5 ppm) as P atoms per ton of the produced polyester resin from the supply port in the middle position of the first tank, and the produced polyester from the supply port of the second tank An EG solution of phosphoric acid in an amount of 0.46 mol (about 14 ppm) as P atoms per ton of resin is continuously added, and an average residence time of 2.5 hours in each tank at normal pressure, a temperature of 260 The reaction was carried out at ° C. The esterification rate of the reaction product of the first esterification reactor was 75%.

  Subsequently, the esterification reaction product is continuously taken out from the second esterification reaction apparatus, and continuously into a two-stage continuous polycondensation reaction apparatus provided with a stirrer, a partial condenser, a raw material charging port and a product discharge port. Supplied. Esterification reaction of EG solution of antimony trioxide in an amount of 1.24 mol (about 150 ppm) as Sb atoms per ton of produced polyester from the polycondensation catalyst supply pipe connected to the esterification reaction product transportation pipe The product was supplied to the product, and polycondensation was performed at about 270 ° C. under reduced pressure in the continuous polycondensation reaction apparatus. The obtained PET had an IV of 0.53.

  The cooling water at the time of chip formation is ion exchange water having a sodium content of 0.1 ppm, a calcium content of about 0.1 ppm, a magnesium content of about 0.05 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. under a nitrogen atmosphere, further preheated to about 200 ° C. under a nitrogen atmosphere, and then sent to a continuous solid-phase polymerization reactor for solid phase polymerization at about 208 ° C. under a nitrogen atmosphere. . After the solid phase polymerization, fines were removed by continuous treatment in a sieving step and a fine removal step.

The obtained PET had an IV of 0.72, a DEG content of 2.7 mol%, an AA content of 3.6 ppm, and a cyclic trimer content of 0.35 wt%. Further, the number of precipitate particles was as small as 200 particles / mm ^2, and it was confirmed that almost all the precipitate particles were composed of Mg atoms and P atoms.
The properties of the obtained PET are shown in Table 1.

(Polyester 2 (Pes2), Polyester 3 (Pes3))
Polyester 2 and polyester 3 were obtained by reacting in the same manner as 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.

(Polyester 4 (Pes4))
A polyester 4 was obtained by reacting in the same manner as the polyester 1 except that isophthalic acid was used as a copolymerization component. The properties of the obtained PET are shown in Table 1.

(Polyester 5 (Pes5))
A polyester 5 was obtained by reacting in the same manner as the polyester 2 except that isophthalic acid was used as a copolymerization component. The properties of the obtained PET are shown in Table 1.

(Polyester 6 (Pes6))
Using the same apparatus as in Example 1, the EG slurry of TPA adjusted to a molar ratio of EG to TPA of 1.7 was continuously added to the system in which the reaction product in the first esterification reactor was present. Supplied. At the same time, an EG solution of magnesium acetate tetrahydrate is supplied from a supply port different from the EG slurry supply port of TPA to 4.0 mol (about 97 ppm with respect to the produced polyester) as Mg atoms per ton of the produced polyester. An EG solution of phosphoric acid is continuously supplied from another supply port so that P atom per ton of the produced polyester is 1.00 mol (about 31 ppm with respect to the produced polyester), and the average residence time is 4 at normal pressure. The reaction was carried out at a temperature of 255 ° C. for a time.

  Esterification reaction of an EG solution of antimony trioxide in an amount of 1.25 mol (about 153 ppm) as Sb atoms per ton of polyester produced from the polycondensation catalyst supply pipe connected to the transport pipe for the esterification reaction product The product was supplied to the product, and polycondensation was performed at about 270 ° C. under reduced pressure in the continuous polycondensation reaction apparatus. The obtained PET had an IV of 0.53. Note that water having a sodium content of about 9.3 ppm, a calcium content of about 10.5 ppm, a magnesium content of about 5.9 ppm, and a silicon content of 12.2 ppm was used as cooling water during chip formation.

This was solid phase polymerized under the same conditions using the same solid phase polymerization equipment as in Example 1, with an IV of 0.72, a DEG content of 2.7 mol%, an AA content of 3.5 ppm, and a cyclic trimer content. 0.35% by weight of PET was obtained.
The number of precipitate particles was as large as 7000 particles / mm ^2, and it was confirmed that 99% or more of these precipitates consisted of Mg atoms and P atoms.
The properties of the obtained PET are shown in Table 1.

(Polyester 7 (Pes7))
A polyester 7 was obtained by reacting in the same manner as the polyester 6 except that isophthalic acid was used as a copolymerization component. The properties of the obtained PET are shown in Table 1.

(Polyester 8 (Pes8))
Polyester 8 was obtained by reacting in the same manner as for polyester 1 except that the amount of Sb catalyst added and the solid phase polymerization time were changed. The properties of the obtained PET are shown in Table 1.

(Polyester 9 (Pes9))
A prepolymer was obtained by melt polycondensation in the same manner as polyester 1 except that the amount of Sb catalyst added was changed.
The obtained 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 ° C. After solid-phase polymerization, fines were removed in the sieving step. The properties of the obtained PET are shown in Table 1.

(Polyester 10 (Pes10))
Polyester 8 was obtained by reacting in the same manner as for polyester 1 except that an EG solution of cobalt acetate tetrahydrate was used instead of the EG solution of magnesium acetate tetrahydrate. The properties of the obtained PET are shown in Table 2.

(Polyester 11 (Pes11))
Polyester 11 was obtained by reacting in the same manner as polyester 2 except that an EG solution of cobalt acetate tetrahydrate was used instead of the EG solution of magnesium acetate tetrahydrate. The properties of the obtained PET are shown in Table 2.

(Polyester 12 (Pes12))
Polyester 12 was obtained by reacting in the same manner as for polyester 1 except that an EG solution of manganese acetate tetrahydrate was used instead of the EG solution of magnesium acetate tetrahydrate. The properties of the obtained PET are shown in Table 2.

(Polyester 13 (Pes13))
Polyester 13 was obtained by reacting in the same manner as polyester 2 except that an EG solution of manganese acetate tetrahydrate was used instead of the EG solution of magnesium acetate tetrahydrate. The properties of the obtained PET are shown in Table 2.

(Polyester 14 (Pes14))
A polyester 14 prepolymer was obtained by reacting in the same manner as the polyester 6 prepolymer except that isophthalic acid was added as a copolymerization component, the amount of antimony trioxide added was increased, and the polycondensation time was shortened.
This prepolymer was subjected to solid phase polymerization in the same manner as polyester 6 except that the solid phase polymerization time was shortened to obtain polyester 14. The properties of the obtained PET are shown in Table 2.

(Polyester 15 (Pes15))
Polyester 15 was obtained by reacting in the same manner as polyester 6 except that the amount of antimony trioxide added was increased.
The properties of the obtained PET are shown in Table 2.

(Polyamide 1)
Toyobo nylon MXD6 resin (T600) manufactured by Toyobo Co., Ltd. was used.

Example 1
A polyester composition obtained by blending the above polyester 1 and polyester 2 pellets in a ratio of 7: 3 was molded at 280 ° C. by the method (12) and injection molded by the method (13). Evaluation was performed using the preform and the hollow molded container. The results are shown in Table 2.
The haze and haze unevenness of the molded plate are 10.6% and 1.4%, respectively, which are no problem, and the shape and dimensions after crystallization of the preformed body plug part are satisfactory, and the AA of the stretched hollow molded body The fluctuation values of the content and the AA content were as small as 9.9 ppm and 0.5 ppm, respectively, and there was no problem in the appearance of the hollow molded container.
The elution amount of antimony atoms determined by the method (16) was 0.50 ppb.

(Comparative Example 1)
As shown in Table 3, the polyester 3 of Comparative Example 1 was evaluated.
Obviously, the haze value and haze spots of the molded plate are high compared to the examples, the shape and dimensions of the preformed body plug part after crystallization are poorly shaped, and the appearance of the hollow molded body is slightly whitened. It was bad. The results are shown in Table 3.

(Comparative Example 2)
As shown in Table 3, the polyester 8 of Comparative Example 2 was evaluated.
Obviously, the haze value and haze spots of the molded plate were high, the shape and dimensions after crystallization of the preformed body plug portion were poor in shape, and the appearance of the hollow molded body was very poor as compared with the examples. The results are shown in Table 3.
Further, in the method for molding a preform according to (13), the elution of antimony atoms obtained by the method of (16) was performed on the stretched hollow molded body obtained in the same manner except that the molten resin temperature was about 295 ° C. The amount was 2.20 ppb.

(Comparative Example 3)
As shown in Table 3, the polyester composition of Comparative Example 3 was evaluated in the same manner as in Example 1.
Obviously, the haze value and haze spots of the molded plate are large when compared with the examples, and the shape and dimensions after crystallization of the preformed body plug part are insufficiently crystallized and poorly shaped. It was bad too. The results are shown in Table 3.

(Comparative Example 4)
As shown in Table 3, the polyester composition of Comparative Example 4 was evaluated in the same manner as in Example 1.
Obviously, the haze value and haze spots of the molded plate are large when compared with the examples, and the shape and dimensions after crystallization of the preformed body plug part are insufficiently crystallized and poorly shaped. Was also very bad. The results are shown in Table 3.

(Example 2)
As shown in Table 3, the polyester composition of Example 2 was evaluated by the method (12) and the method (13).
The results are shown in Table 3. All the evaluated characteristics were as good as in Example 1.

(Comparative Example 5)
As shown in Table 3, the polyester composition of Comparative Example 5 was evaluated in the same manner as in Example 1.
Obviously, when compared with Example 1, the molded plate had a large haze value and haze spots, and the appearance of the stretched molded product was very poor. The results are shown in Table 3.

(Examples 3 and 4)
As shown in Table 3, the polyester compositions of Examples 3 and 4 were evaluated by the method (12) and the method (13).
The results are shown in Table 3. All the evaluated characteristics were as good as in Example 1.

(Comparative Example 6)
As shown in Table 3, the polyester composition of Comparative Example 6 was evaluated in the same manner as in Example 1.
Obviously, the haze value and haze spots of the molded plate were large as compared with the examples, and the appearance of the stretched molded product was very bad. The results are shown in Table 3.

(Example 5)
Evaluation was carried out in the same manner as in Example 1 for the polyester composition of Example 3 in which the above polyester 1,70 parts by weight, polyester 2,30 parts by weight and polyamide 1, 1 part by weight were blended. The results are shown in Table 3. The stretched hollow molded article had a low AA content of 6.8 ppm, had a good appearance, and had no other problems.

  As mentioned above, although the polyester composition of this invention, the polyester molded object which consists of it, and the manufacturing method of the polyester hollow molded object were demonstrated based on several Example, this invention is limited to the structure described in the said Example. Instead, the configuration can be changed as appropriate without departing from the spirit of the invention, for example, by appropriately combining the configurations described in the embodiments.

  Since the polyester composition of the present invention has improved flow characteristics, the amount of aldehyde generated during molding is small, and when formed into a molded body, it can give a molded body excellent in mechanical properties such as pressure resistance. An inexpensive polyester composition comprising a polyester polymerized using at least one selected from the group consisting of antimony compounds as a polyester polymerization catalyst. In addition, since the polyester molded body and the polyester hollow molded body manufacturing method of the present invention use a polyester composition having such characteristics, the flow characteristics are improved, distortion during molding is small, and heat resistance dimensional stability is excellent. Molded products, especially molded products can be produced efficiently by high-speed molding, and it gives a molded product with very good pressure resistance and heat-resistant dimensional stability, and it does not pollute the mold for a long time. It can be used for applications where properties are required.

Plan view of stepped plate Side view of stepped plate

Claims (8)

At least two kinds of ethylene terephthalate containing at least one metal compound selected from Mg compound, Ca compound, Co compound, Mn compound and Zn compound, P compound and Sb compound are the main repeating units. A polyester composition containing polyester as a main component, wherein the difference in intrinsic viscosity of the polyester is in the range of 0.05 to 0.25 deciliter / gram, and Mg metal atoms and Ca metals contained in each polyester The number of precipitate particles of 1 μm or more composed of at least one metal atom from atoms, Co metal atoms, Mn metal atoms and Zn metal atoms and P atoms, and the difference in the number of precipitate particles are 5000 particles / mm ² , respectively. And a polyester composition characterized by being 1000 / mm ² or less. Spherical crystals formed when the molded body obtained from each polyester has a crystallization temperature when the temperature is lowered and a difference between the crystallization temperatures when the temperature is lowered is 200 ° C. or less and less than 18 ° C. 2. The polyester composition according to claim 1, wherein the number and the difference thereof are 2 × 10 ^{9 to} 90 × 10 ⁹ pieces / m ² and less than 30 × 10 ⁹ pieces / m ² .   3. The polyester composition according to claim 1, wherein the acetaldehyde content is 10 ppm or less and the cyclic trimer content is 0.70 wt% or less. The polyester composition according to any one of claims 1 to 3, wherein the polyester composition contains, as main components, the following polyester A and polyester B having ethylene terephthalate as a main repeating unit.
Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.80 deciliter / gram, diethylene glycol component is 1.0 to 5.0 mol% of all glycol components, isophthalic acid component is 0 to 3.0 mol of all acid components %, The polyester whose crystallization temperature at the time of temperature rise is 140-180 degreeC.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.95 deciliter / gram, diethylene glycol component is 1.0 to 5.0 mol% of all glycol components, isophthalic acid component is 0 to 3.0 mol of all acid components %, The polyester whose crystallization temperature at the time of temperature rise is 140-180 degreeC.   A polyester molded article obtained by molding the polyester composition according to claim 1.   A polyester stretched hollow molded article comprising the polyester composition according to any one of claims 1 to 4, wherein an elution amount of antimony atoms when an elution test is performed is 2.0 ppb or less.   The polyester molded article according to claim 5, wherein the polyester molded article is a coating obtained by melt-extruding a polyester composition on a substrate. The polyester composition according to any one of claims 1 to 4 is kneaded and molded under conditions where the molten resin temperature in the molding machine is 260 to 305 ° C and the melt residence time in the molding machine is 5 to 300 seconds. A method for producing a polyester hollow molded article.

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