JPWO2006062148A1 - POLYESTER RESIN, POLYESTER MOLDED ARTICLE COMPRISING THE SAME AND PROCESS FOR PRODUCING THE SAME - Google Patents

Abstract

The present invention is a polyester resin containing as a main component at least two polyesters having substantially the same composition, wherein the difference in intrinsic viscosity of the polyester is in the range of 0.05 to 0.30 deciliter / gram, The polyester is a polyester polymerized using one or more selected from the group consisting of aluminum and its compounds as a catalyst, and the amount of aldehydes generated during molding is small, and the molded product When this is done, a polyester resin is obtained which gives a molded article having excellent mechanical properties such as pressure resistance.

Description

  The present invention uses, as a catalyst, at least one selected from the group consisting of aluminum and its compounds, which is suitably used as a raw material for hollow molded articles including beverage bottles, sheet-like articles, stretched films and the like. Polyester resin composed of polyester polymerized by polymerization and polyester molded body comprising the same, in particular due to improved flow characteristics, excellent transparency and little variation in transparency, generation of aldehydes such as acetaldehyde during molding and its variation The present invention relates to a hollow molded body excellent in pressure resistance or pressure resistance and heat-resistant dimensional stability, and a sheet-like material and a stretched film excellent in transparency, slipperiness and dimensional stability after molding. Moreover, this invention relates to the manufacturing method of the polyester molded object which has the said characteristic.

Polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) are excellent in both mechanical properties and chemical properties, and thus have high industrial value, such as fibers, films, sheets, and bottles. Widely used as such.
As a material for containers such as seasonings, oils, beverages, cosmetics, and detergents, various resins are employed depending on the type of filling contents and the purpose of use.
Of these, polyester is excellent in mechanical strength, heat resistance, transparency and gas barrier properties, and is particularly suitable as a material for molded articles such as beverage filling containers such as juices, soft drinks and carbonated drinks. is there.
For example, such a polyester is supplied to a molding machine such as an injection molding machine to form a preform for a hollow molded body, and the preform is inserted into a mold having a predetermined shape and subjected to stretch blow molding for soft drinks. It can be made into a hollow molded container, or it is molded into a heat-resistant or pressure-resistant hollow molded container by heat-treating the preform plug part after heat treatment (crystallization of the plug part) and heat-treating the body part (heat set). It is common. In order to improve the heat resistance of the bottle body, for example, a method of heat-treating the stretch blow mold at a high temperature is employed (see, for example, Patent Document 1). However, if a large number of bottles are continuously formed using the same mold by such a method, the bottle obtained with a long time operation is whitened, the transparency is lowered, and only a bottle having no commercial value can be obtained. . It has been found that this is because a deposit due to PET is attached to the mold surface, resulting in mold fouling, and this mold fouling is transferred to the bottle surface. In particular, in recent years, the molding speed has been increased along with the downsizing of the bottle. From the viewpoint of productivity, the melting time at the time of injection molding is shortened, the heating time for crystallization of the plug portion is shortened, or the mold. Contamination has become a greater problem and is not satisfactory with conventional PET, and a solution is desired.
Japanese Examined Patent Publication No.59-6216

In the case of PET, in order to solve such a problem of mold contamination, conventionally, a method of reducing the cyclic trimer, which is the main component of the deposit on the mold surface, by solid-phase polymerization in advance (for example, In this method, the cyclic trimer is regenerated when it is remelted and preformed, and its effect is insufficient. Also disclosed are a method of deactivating a catalyst by contacting PET with water (for example, see Patent Document 3) and a PET having a catalyst deactivated by water treatment (for example, see Patent Document 4). Yes. However, even with the above method, the amount of cyclic oligomers generated at the time of melting is reduced and the mold fouling is temporarily reduced. However, the crystallization speed is unstable, and defects such as whitened flow patterns and bubbles occur. There is a problem that only a bottle that is easy and has poor transparency can be obtained, and a solution is awaited.
JP 55-89330 A Japanese Patent Laid-Open No. 3-47830 Japanese Patent Laid-Open No. 3-72524

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

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

For these reasons, various measures have been taken to reduce the acetaldehyde content in the polyester. As these measures, for example, a method of reducing the AA content by solid-phase polymerization of melt-polycondensed polyester (for example, see Patent Document 5), 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 6), 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 7), polyester containers made of a polyester composition containing a specific polyamide whose terminal amino group concentration is regulated within a certain range in thermoplastic polyester (for example, see Patent Document 8), polyester prepolymer After conditioning the moisture content to 2000 ppm or more, crystallization and solid phase polymerization (For example, refer to Patent Document 9), a method in which polyester particles are treated with hot water at 50 to 200 ° C., and then subjected to heat treatment under reduced pressure or in an inert gas flow (for example, refer to Patent Document 10), thermoforming. There have been proposed a method for reducing 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 problem-free level, and the problem remains unsolved.
Further, a blend of solid-phase polymerized PET and copolymerized polyethylene terephthalate (for example, see Patent Document 11) has been proposed, and by using this, the AA content of the hollow molded body can be reduced. Since the copolymer component is present, there is a problem in the heat resistance and pressure resistance of the obtained molded body, which is not satisfactory and a solution is awaited.
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 JP 58-45254 A

In addition, a method for producing a heat-resistant polyester container in which a preform formed from two kinds of molten PET compositions having different intrinsic viscosities of 0.03 or more is treated with a heat-setting mold under specific temperature conditions (for example, Patent Document 12). And a heat-resistant polyester container obtained (see, for example, Patent Document 13), having an intrinsic viscosity of 0.60 to 0.70 dl / g, a specific temperature increase crystallization temperature, and a specific temperature decrease crystallization temperature Production of a heat resistant polyester container for stretching and blowing a preform from a mixture of polyester and a polyester having an intrinsic viscosity of 0.77 to 0.90 dl / g, a specific crystallization temperature at elevated temperature and a specified crystallization temperature at lowered temperature Although methods (for example, see Patent Document 14) have been proposed, a molded article having stable transparency and a reduced acetaldehyde content can be obtained by these methods. There are still problems to.
Japanese Examined Patent Publication No. 62-43851 Japanese Examined Patent Publication No. 62-58973 Japanese Patent Laid-Open No. 10-287799

In general, PET used for these 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-mentioned catalysts, the antimony catalyst is a catalyst that is inexpensive and has excellent catalytic activity. However, when it is used in a main component, that is, in an added amount such that a practical polymerization rate is exhibited. Because antimony is deposited during polycondensation, darkening and foreign matter occur in the polyester, and the resulting PET has a faster crystallization rate and superior transparency compared to the case where a germanium compound or a titanium compound is used as a catalyst. It is very difficult to obtain a hollow molded body, particularly a hollow molded body excellent in heat resistance and transparency. It is also very difficult to obtain a PET hollow molded article with a reduced acetaldehyde content. Therefore, as described below, the present situation addresses this problem by copolymerizing the third component and molding at a low temperature. In addition, for applications requiring transparency such as PET bottles, as a method for solving the problems of the antimony catalyst, the transparency can be improved by defining the use ratio of the antimony compound and the phosphorus compound (for example, Patent Document 15) is disclosed. However, it cannot be said that a hollow molded product made of polyester obtained by this method has sufficient transparency.
JP-A-6-279579

Under such circumstances, polyesters that do not contain antimony at all or do not contain antimony as a main catalyst are desired, and various studies have been conducted on polycondensation catalysts that can replace antimony catalysts such as antimony trioxide. Titanium compounds and tin compounds represented by tetraalkoxy titanate have already been proposed. However, polyesters produced using these are susceptible to thermal degradation during melt molding, and the polyesters are remarkably colored.
As an attempt to overcome such problems when a titanium compound is used as a polycondensation catalyst, a polyester resin having a low acetaldehyde content and excellent color tone (for example, see Patent Documents 16 and 17) has been proposed. . However, although these techniques can reduce the coloration of the obtained polyester resin, the color tone and acetaldehyde content of the obtained molded product are not satisfactory.
JP 2001-200044 A JP 2001-48966 A

  On the other hand, aluminum compounds are generally known to have poor catalytic activity. Among aluminum compounds, aluminum chelate compounds have been reported to have higher catalytic activity as polycondensation catalysts than other aluminum compounds, but they have sufficient catalytic activity compared to the antimony compounds and titanium compounds described above. However, no example has been known in which a polyester polymerized using an aluminum compound as a catalyst is used for a hollow molded body or a film.

Germanium compounds have already been put to practical use as catalysts that have excellent catalytic activity other than antimony compounds and give polyesters with excellent thermal stability and thermal oxidation stability, but this catalyst is very expensive. There are problems and problems that the catalyst concentration in the reaction system changes due to the tendency of distilling out of the reaction system during polymerization, making it difficult to control the polymerization. is there.
With the above circumstances, a polymerization catalyst having a metal component other than antimony and germanium as the main metal component of the catalyst is used, and has excellent catalytic activity and hardly causes thermal deterioration during melt molding (a) thermal stability, A polyester that is excellent in at least one of (b) thermal oxidation stability and (c) hydrolysis resistance, has a small amount of foreign matter, has excellent flow characteristics, transparency and color tone, and has a reduced aldehyde content is desired. ing.

Plan view of stepped plate Side view of stepped plate

  The present invention solves the problems of the conventional methods described above, uses a polymerization catalyst in which a metal component other than antimony and germanium is the main metal component of the catalyst, has excellent transparency and little variation in transparency, and molding The formation and fluctuation of aldehydes such as acetaldehyde at the time are suppressed, and hollow molded products with excellent pressure resistance or heat-resistant dimensional stability, especially hollow molded products with excellent pressure resistance and heat-resistant pressure resistance at lower temperatures An object of the present invention is to provide an inexpensive polyester resin that can be efficiently produced by high-speed molding, a polyester molded body comprising the same, and a method for producing the same.

The inventors of the present invention have reached the present invention as a result of intensive studies to achieve the above object.
The present invention is as follows.

(1) A polyester resin containing as a main component at least two polyesters having substantially the same composition, wherein the difference in intrinsic viscosity of the polyester is in the range of 0.05 to 0.30 deciliter / gram, A polyester resin, wherein the polyester is a polyester polymerized using one or more selected from the group consisting of aluminum and its compounds as a catalyst.

(2) A polyester resin containing as a main component at least two kinds of polyesters having substantially the same composition, wherein the difference in intrinsic viscosity of the polyester is in the range of 0.05 to 0.30 deciliter / gram, A polyester resin, characterized in that the polyester is a polyester polymerized using a catalyst comprising one kind selected from the group consisting of aluminum and its compounds, and a phenolic compound and / or a phosphorus compound.

(3) The polyester resin according to (1) or (2), wherein the cyclic ester oligomer content is 70% or less of the cyclic ester oligomer content of the melt polycondensation polyester.

(4) The said polyester resin contains the following polyester A and polyester B which have ethylene terephthalate as a main repeating unit as a main component, The crystallization temperature at the time of temperature fall of polyester A, and the crystal | crystallization at the time of temperature fall of polyester B The polyester resin according to any one of (1) to (3), wherein the difference in the conversion temperature is within 20 ° C.
Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.80 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at the time of temperature increase measured by DSC is 140 to 180 ° C., and the crystallization temperature at the time of temperature decrease is Polyester that is 160-200 ° C.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.95 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at the time of temperature increase measured by DSC is 140 to 180 ° C., and the crystallization temperature at the time of temperature decrease is Polyester that is 160-200 ° C.

(5) The polyester resin according to (4), wherein the thermal stability parameter (TS) of the polyester A and the polyester B satisfies the following formula (1).
TS <0.30 (1) Formula (TS is a melting test (1 g of a polyester resin chip is placed in a glass test tube and vacuum dried at 130 ° C. for 12 hours, and then melted at 300 ° C. for 2 hours in a non-circulating nitrogen atmosphere) It is a value obtained by measuring the intrinsic viscosity before and after) and using the following formula.
TS = 0.245 {[IV] _f2 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f2 indicate intrinsic viscosities (unit: deciliter / gram) before and after the melting test, respectively. )

(6) The polyester resin according to (4) or (5), wherein the thermal oxidation stability parameter (TOS) of the polyester A and the polyester B satisfies the following formula (2).
TOS <0.20 (2) (TOS is a heat test (polyester resin chips are frozen and pulverized to a powder of 20 mesh or less, vacuum-dried at 130 ° C. for 12 hours, 0.3 g is put in a glass test tube, This is a value obtained by measuring the intrinsic viscosity before and after vacuum drying at 70 ° C. for 12 hours and then heating at 230 ° C. for 15 minutes in air dried with silica gel and using the following formula.
TOS = 0.245 {[IV] _f1 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f1 indicate intrinsic viscosities (unit: deciliter / gram) before and after the heating test, respectively. )

(7) The polyester resin according to any one of claims 4 to 6, wherein the hydrolysis resistance parameter (HS) of the polyester A and the polyester B satisfies the following formula (3).
HS <0.10 (3) Formula (HS is a hydrolysis test (freeze-pulverized polyester resin chips are made into a powder of 20 mesh or less, vacuum-dried at 130 ° C. for 12 hours) 1 g of pure water is put into a beaker with 100 ml of pure water. It is a value obtained by measuring the intrinsic viscosity before and after stirring for 6 hours under the condition of heating and pressurizing at 130 ° C. in a closed system and using the following formula.
HS = 0.245 {[IV] _f3 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f3 indicate intrinsic viscosities (unit: deciliter / gram) before and after the hydrolysis test, respectively. )

(8) The polyester resin according to any one of (1) to (7), wherein an increase amount of the cyclic ester oligomer when melted at a temperature of 290 ° C. for 60 minutes is 0.40% by weight or less.

(9) The composition according to any one of (1) to (8), wherein at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin, and a polyacetal resin is blended in an amount of 0.1 ppb to 1000 ppm. Polyester resin.

(10) A polyester molded article obtained by molding the polyester resin according to any one of (1) to (9).

(11) The polyester molded body described in (10) is a hollow molded body preform, a sheet-shaped preform, or a stretched film or stretch blow hollow formed by stretching these preforms in at least one direction. A polyester molded body, which is any one selected from molded bodies.

(12) A polyester molded article, wherein the polyester molded article according to (10) is a coating obtained by melt-extruding a polyester resin on a substrate.

(13) The polyester resin according to any one of (1) to (9) is kneaded and molded under the conditions that the molten resin temperature in the molding machine is 260 to 295 ° C. and the melt residence time in the molding machine is 10 to 500 seconds. A method for producing a polyester molded body, comprising:

  Hereinafter, embodiments of the polyester resin of the present invention, a polyester molded body comprising the same, and a method for producing the polyester molded body will be specifically described.

When the polyester resin of the present invention is a polyester resin containing, as a main component, a polyester polymerized using at least two kinds of substantially the same composition selected from the group consisting of aluminum and a compound thereof as a catalyst The difference in intrinsic viscosity of the polyester is in the range of 0.05 to 0.30 deciliter / gram. The polyester resin of the present invention improves the fluidity at the time of melting in the extruder by the action of the polyester having a low intrinsic viscosity, so that it can be molded at a lower molding temperature, and the resulting aldehydes such as acetaldehyde can be produced. It becomes possible to reduce, and a molded object with little content of aldehydes can be obtained. In addition, it is advantageous to obtain a bottle with further improved strength, and by using the polyester resin of the present invention, it is possible to easily form a thin bottle that has no problem in terms of strength of the bottle even if the body thickness is reduced. .
In addition, because the molding temperature can be lowered for the same reason, it is possible to suppress the formation of cyclic ester oligomers during melt molding, and in particular, small hollow molded products can be efficiently produced by high-speed molding, and therefore productivity. And a polyester resin excellent in long-term continuous moldability with little fouling of the mold.

  The difference in intrinsic viscosity of the polyester is preferably 0.06 to 0.27 deciliter / gram, more preferably 0.07 to 0.23 deciliter / gram, particularly preferably 0.10 to 0.20 deciliter / gram. . When the intrinsic viscosity difference is less than 0.05 deciliter / gram, the content of aldehydes such as acetaldehyde in the obtained molded product cannot be reduced, and the flavor retention cannot be improved. Further, when the above-mentioned intrinsic viscosity difference exceeds 0.30 deciliter / gram, a thickness unevenness, a whitened flow pattern, or the like occurs in the obtained molded product, which causes a problem.

When the polyester resin of the present invention is composed of two kinds of polyesters, the blending ratio is 95/5 to 5/95, preferably 92/8 to 8/92, more preferably 90/10 to 10 in weight ratio. If the value is outside this range, the object of the present invention is not achieved.
Here, “substantially the same” means that 95 mol% or more is the same for both the acid component and glycol component of the polyester, more preferably 97 mol% or more, and particularly 98 mol% or more. preferable.

  When the polyester resin 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. Hereinafter, the maximum polyester regarding the intrinsic viscosity is referred to as polyester B, and the minimum polyester is referred to as polyester A.

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 that have been subjected to contact treatment with water under conditions where 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 hydrolysis method 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 impacts during transportation, etc., so that there is a problem that the fluctuation of the transparency and crystallization speed of the molded body when these are used becomes very large. The fluctuation is a big problem. In addition, the method using the melt treatment has problems such as an influence on flavor retention and coloring due to an increase in aldehydes such as acetaldehyde during the treatment. Therefore, the polyester according to the present invention does not include polyester that has been hydrolyzed by a method such as heat treatment under pressure with water or the like, and polyester that has undergone melt treatment to reduce IV.

Aluminum and its compound used as a catalyst will be described later.
The polyester resin of the present invention contains at least two kinds of substantially the same composition selected from the group consisting of aluminum and its compounds, and a phenolic compound and / or a phosphorus compound. In the case of a polyester resin containing as a main component a polyester polymerized using a polyester, the difference in intrinsic viscosity of the polyester is preferably in the range of 0.05 to 0.30 deciliter / gram. The phenolic compound and phosphorus compound used as the catalyst will be described later.

  The polyester of the present invention is a thermoplastic polyester mainly obtained from an aromatic dicarboxylic acid component and a glycol component, preferably a polyester containing aromatic dicarboxylic acid units of 70 mol% or more of the acid component, more preferably A polyester in which the aromatic dicarboxylic acid unit contains 85 mol% or more of the acid component, and particularly preferably a polyester in which the aromatic dicarboxylic acid unit contains 95 mol% or more of the acid component.

  Examples of the aromatic dicarboxylic acid component constituting the polyester of the present invention include terephthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid and other aromatic dicarboxylic acids and their functions. And the like.

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

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

  The glycol as a copolymer component used when the polyester of the present invention is a copolymer includes diethylene glycol, 1,3-trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, Aliphatic glycols such as decamethylene glycol, 2-ethyl-2-butyl-1,3-propanediol, neopentyl glycol, dimer glycol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexane Alicyclic glycols such as dimethylol, 1,4-cyclohexanedimethylol, 2,5-norbornane dimethylol, xylylene glycol, 4,4′-dihydroxybiphenyl, 2,2-bis (4′-β-hydroxy) Toxylphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfonic acid, aromatic glycols such as alkylene oxide adducts of bisphenol A, polyalkylenes such as polyethylene glycol and polybutylene glycol And glycols.

  Furthermore, examples of the polyfunctional compound as the copolymer component used when the polyester of the present invention is a copolymer include trimellitic acid and pyromellitic acid as the acid component, and glycerin as the glycol component. And pentaerythritol. The amount of copolymerization component used should be such that the polyester remains substantially linear. Monofunctional compounds such as benzoic acid and naphthoic acid may be copolymerized.

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

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

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

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

Another preferred example of the polyester of the present invention is a polyester in which the main structural unit is composed of 1,4-cyclohexanedimethylene terephthalate, and more preferably 70 mol% or more of 1,4-cyclohexanedimethylene terephthalate units. The copolyester containing is particularly preferably a polyester containing 90 mol% or more of 1,4-cyclohexanedimethylene terephthalate units.
Examples of these thermoplastic polyesters include poly-1,4-cyclohexanedimethylene terephthalate (PCT), poly (1,4-cyclohexanedimethylene terephthalate-ethylene terephthalate) copolymer, and the like.

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

First, when a low polymer is produced by an esterification reaction, 1.02 to 2.0 mol, preferably 1.03 to 1.4 mol of ethylene glycol is added to 1 mol of terephthalic acid or an ester derivative thereof. The contained slurry is prepared and continuously supplied to the esterification reaction step.
In the esterification reaction, water or alcohol produced by the reaction is removed from the system by a rectification column under the condition that ethylene glycol is refluxed using a multistage apparatus in which at least two esterification reactors are connected in series. While implementing. The temperature of the first stage esterification reaction is 240 to 270 ° C., preferably 245 to 265 ° C., and the pressure is 0.2 to 3 kg / cm ² G, preferably 0.5 to ² kg / cm ² G. The temperature of the esterification reaction in the final stage is usually 250 to 280 ° C, preferably 255 to 275 ° C, and the pressure is usually 0 to 1.5 kg / cm ² G, preferably 0 to 1.3 kg / cm ² G. . When carried out in three or more stages, the reaction conditions for the esterification reaction in the intermediate stage are conditions between the reaction conditions for the first stage and the reaction conditions for the final stage. The increase in the reaction rate of these esterification reactions is preferably distributed smoothly at each stage. Ultimately, it is desirable that the esterification reaction rate reaches 90% or more, preferably 93% or more. By these esterification reactions, low-order condensates having a molecular weight of about 500 to 5,000 are obtained.

When terephthalic acid is used as a raw material, the esterification reaction can be carried out without a catalyst by the catalytic action of terephthalic acid as an acid, but may be carried out in the presence of a polycondensation catalyst.
Also, tertiary amines such as triethylamine, tri-n-butylamine, benzyldimethylamine, quaternary ammonium hydroxides such as tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, trimethylbenzylammonium hydroxide, and lithium carbonate When a small amount of a basic compound such as sodium carbonate, potassium carbonate or sodium acetate is added, the proportion of dioxyethylene terephthalate component units in the main chain of polyethylene terephthalate is relatively low (5% relative to all diol components). Mol% or less).

Next, in the case of producing a low polymer by transesterification, 1.1 to 2.0 mol, preferably 1.2 to 1.5 mol of ethylene glycol was contained with respect to 1 mol of dimethyl terephthalate. The solution is prepared and continuously fed to the transesterification step.
The transesterification reaction is carried out while removing methanol generated by the reaction outside the system using a rectification column under the condition that ethylene glycol is distilled back using an apparatus in which 1 to 2 transesterification reactors are connected in series. To do. The temperature of the first stage transesterification is 180 to 250 ° C, preferably 200 to 240 ° C. The temperature of the transesterification reaction in the final stage is usually 230 to 270 ° C., preferably 240 to 265 ° C., and as the transesterification catalyst, fatty acid salts such as Zn, Cd, Mg, Mn, Co, Ca, Ba, carbonates Alternatively, Pb, Zn, Sb, Ge oxide or the like is used. A low-order condensate having a molecular weight of about 200 to 500 is obtained by these transesterification reactions.

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

   Subsequently, the obtained low-order condensate is supplied to a multistage liquid phase condensation polymerization process. The polycondensation reaction conditions are as follows: the first stage polycondensation reaction temperature is 250 to 290 ° C., preferably 260 to 280 ° C., and the pressure is 500 to 20 Torr, preferably 200 to 30 Torr. The temperature is 265 to 300 ° C., preferably 275 to 295 ° C., and the pressure is 10 to 0.1 Torr, preferably 5 to 0.5 Torr. When carried out in three or more stages, the reaction conditions for the intermediate stage polycondensation reaction are conditions between the reaction conditions for the first stage and the reaction conditions for the last stage. The degree of increase in intrinsic viscosity achieved in each of these polycondensation reaction steps is preferably distributed smoothly. A single-stage polycondensation apparatus may be used for the polycondensation reaction.

  The polycondensation reaction is performed using a polycondensation catalyst. As the aluminum or aluminum compound constituting the polycondensation catalyst used in the present invention, known aluminum compounds can be used without limitation in addition to metallic aluminum. These compounds are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries and the like.

Specific examples of aluminum compounds include aluminum formate, aluminum acetate, basic aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, aluminum trichloroacetate, and aluminum lactate. , Carboxylates such as aluminum citrate, aluminum salicylate, inorganic acid salts such as aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate, aluminum phosphonate, aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum iso-propoxide, aluminum n-butoxide, aluminum t-butoxa Aluminum alkoxides such as aluminum, aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethylacetoacetate diiso-propoxide, and other organic chelate compounds, trimethylaluminum, triethylaluminum and other organoaluminum compounds and their partial hydrolysis Examples include decomposed products and aluminum oxide. Of these, carboxylates, inorganic acid salts and chelate compounds are preferred, and among these, aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred.

The aluminum compound is added so that the residual amount of Al in the produced polymer is in the range of 5 to 200 ppm, preferably 5 to 10 ppm, more preferably 8 to 70 ppm, still more preferably 10 to 50 ppm, and most preferably 10 to 40 ppm. .
It is preferable that the amount of the aluminum compound added be small because the generation of foreign matter is suppressed and a polyester having excellent thermal stability, thermal oxidation stability and the like can be produced. If the Al residual amount is 200 ppm or less, the formulas (2) and (3) are satisfied, but if the Al residual amount exceeds 70 ppm, the thermal stability parameter (TS) of the formula (1) is 0. May exceed 30.

  The phenolic compound constituting the polycondensation catalyst used in the present invention is not particularly limited as long as it is a compound having a phenol structure. For example, 2,6-di-tert-butyl-4-methylphenol, 2, 6-di-tert-butyl-4-ethylphenol, 2,6-dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, 2,6-di-tert-amyl-4-methylphenol, 2,6-di-tert-octyl-4-n-propylphenol, 2,6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-tert-butylphenol, 2-tert-butyl-2 -Ethyl-6-tert-octylphenol, 2-isobutyl-4-ethyl-6-tert-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, 1,1,1-tris (4-hydroxy Phenyl) ethane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) ) Butane, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert- Butyl-4-hydroxyphenyl) propionate], 2,2-thiodiethylene-bis [3- (3,5-di-tert-butyl-4,4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3, 5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris [(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl] Isocyanurate, tris (4-tert-butyl-2,6-dimethyl-3-hydroxybenzyl) isocyanurate, 2,4-bis (n-octyl) Ruthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, tetrakis [methylene (3,5-di-tert-butyl-4-hydroxy) hydrocinnamate ] Methane, bis [(3,3-bis (3-tert-butyl-4-hydroxyphenyl) butyric acid) glycol ester, N, N'-bis [3- (3,5-di-tert-butyl- 4-hydroxyphenyl) propionyl] hydrazine, 2,2′-ogizamide bis [ethyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], bis [2-tert-butyl-4-methyl -6- (3-tert-butyl-5-methyl-2-hydroxybenzyl) phenyl] terephthalate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4 -Hydroxybenzyl) benzene, 3,9-bis [1,1-dimethyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8, 10-te Traoxaspiro [5,5] undecane, 2,2-bis [4- (2- (3,5-di-tert-butyl-4-hydroxycinnamoyloxy)) ethoxyphenyl] propane, β- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid alkyl ester, tetrakis- [methyl-3- (3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionate] methane, octadecyl-3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, thiodiethylene-bis [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], hexamethylene Bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis-[-3- (3'-tert- Til-4-hydroxy-5-methylphenyl)] propionate, 1,1,3-tris [2-methyl-4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -5-tert-butylphenyl] butane. Two or more of these can be used in combination. Of these, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis- [methyl-3- (3 ', 5' -Di-tert-butyl-4-hydroxyphenyl) propionate] methane, thiodiethylene-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] are preferred.

  By adding these phenol compounds at the time of polymerization of the polyester, the catalytic activity of the aluminum compound is improved and the thermal stability of the polymerized polyester is also improved.

The amount of the phenolic compound used in the present invention is preferably 5 × 10 ^{−7 to} 0.01 mol with respect to the number of moles of all constituent units of the carboxylic acid component such as dicarboxylic acid and polyvalent carboxylic acid of the obtained polyester. More preferably, it is 1 × 10 ^{−6 to} 0.005 mol.

In the present invention, a phosphorus compound may be used together with the phenol compound.
The phosphorus compound constituting the polycondensation catalyst used in the present invention is not particularly limited, but phosphoric acid and phosphoric acid esters such as trimethyl phosphoric acid, triethyl phosphoric acid, phenyl phosphoric acid, triphenyl phosphoric acid, phosphorous acid And trimethyl phosphite, triethyl phosphite, triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4'-biphenylenedi Examples thereof include phosphites such as phosphites.

  More preferable phosphorus compounds constituting the polycondensation catalyst used in the present invention include phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds. And at least one P compound selected from the group. In addition to the effect of improving the physical properties such as thermal stability of polyester by containing these phosphorus compounds, the catalyst is obtained by using these phosphorus compounds together with the Al compound used in the present invention during the polymerization of polyester. An activity improvement effect is observed. Among these, use of a phosphonic acid compound is preferable because of its great effect of improving physical properties and improving catalytic activity. Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  The phosphonic acid-based compound, phosphinic acid-based compound, phosphine oxide-based compound, phosphonous acid-based compound, phosphinic acid-based compound, and phosphine-based compound referred to in the present invention are represented by the following formulas (Formula 1) to (Formula 6), respectively. It refers to a compound having the structure represented.

  Examples of the phosphonic acid compound constituting the polycondensation catalyst used in the present invention include dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, and benzylphosphone. Examples include diethyl acid. Examples of the phosphinic acid-based compound used in the present invention include diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, and phenylphenylphosphinate. Examples of the phosphine oxide compound used in the present invention include diphenylphosphine oxide, methyldiphenylphosphine oxide, triphenylphosphine oxide, and the like.

  Among the phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds, the phosphorus compound constituting the polycondensation catalyst used in the present invention is represented by the following formula (Formula 7). ) To (Chemical Formula 12) are preferred.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  Further, as the phosphorus compound constituting the polycondensation catalyst used in the present invention, when the compounds represented by the following general formulas (Chemical Formula 13) to (Chemical Formula 15) are used, the physical property improving effect and the catalytic activity improving effect are particularly large. preferable.

(In the formulas (Chemical Formula 13) to (Chemical Formula 15), R ¹ , R ⁴ , R ⁵ , and R ⁶ are each independently hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group. R ² and R ³ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group. However, the hydrocarbon group may contain an alicyclic structure such as cyclohexyl or an aromatic ring structure such as phenyl or naphthyl.)

The phosphorus compound constituting the polycondensation catalyst used in the present invention is a compound in which R ¹ , R ⁴ , R ⁵ and R ⁶ are groups having an aromatic ring structure in the above formulas (Chemical Formula 13) to (Chemical Formula 15). Is particularly preferred.

  Examples of the phosphorus compound constituting the polycondensation catalyst used in the present invention include dimethyl methylphosphonate, diphenyl methylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate. , Diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenylphenylphosphinate, diphenylphosphine oxide, methyldiphenylphosphine oxide, triphenylphosphine oxide, and the like. Of these, dimethyl phenylphosphonate and diethyl benzylphosphonate are particularly preferred.

  Among the phosphorus compounds described above, in the present invention, a metal salt compound of phosphorus is particularly preferable as the phosphorus compound. The phosphorus metal salt compound is not particularly limited as long as it is a metal salt of a phosphorus compound. However, when a metal salt of a phosphonic acid compound is used, the physical properties improving effect and catalytic activity improving effect of the polyester, which are the problems of the present invention, are improved. Largely preferred. Examples of the metal salt of the phosphorus compound include a monometal salt, a dimetal salt, and a trimetal salt.

  Further, among the above-described phosphorus compounds, when the metal portion of the metal salt is selected from Li, Na, K, Be, Mg, Sr, Ba, Mn, Ni, Cu, and Zn, the catalytic activity is improved. Is preferable. Of these, Li, Na, and Mg are particularly preferable.

  As the phosphorus metal salt compound constituting the polycondensation catalyst used in the present invention, when at least one selected from the compounds represented by the following general formula (Chemical Formula 16) is used, the physical property improving effect and the catalytic activity improving effect are obtained. Largely preferred.

(In the formula (Chem. 16), R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a hydrocarbon group having 1 to 50 carbon atoms. R ² represents , Hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, and a hydrocarbon group having 1 to 50 carbon atoms, R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl. A hydrocarbon group having 1 to 50 carbon atoms including a group or carbonyl, l is an integer of 1 or more, m is 0 or an integer of 1 or more, l + m is 4 or less, M is (l + m And n represents an integer greater than or equal to 1. The hydrocarbon group may contain an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic ring structure such as phenyl or naphthyl.)

Examples of R ¹ include phenyl, 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl, and the like. Examples of R ² include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, long-chain aliphatic group, phenyl group, naphthyl group, Examples thereof include a substituted phenyl group, a naphthyl group, and a group represented by —CH ₂ CH ₂ OH. Examples of R ³ O ⁻ include hydroxide ions, alcoholate ions, acetate ions, and acetylacetone ions.

  Among the compounds represented by the general formula (Chemical Formula 16), it is preferable to use at least one selected from the compounds represented by the following General Formula (Chemical Formula 17).

(In the formula (Chemical Formula 17), R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a hydrocarbon group having 1 to 50 carbon atoms. R ³ represents , Hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, or a hydrocarbon group having 1 to 50 carbon atoms including carbonyl, l is an integer of 1 or more, and m is 0 or an integer of 1 or more. , L + m is 4 or less, M represents a (l + m) -valent metal cation, and the hydrocarbon group contains an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic ring structure such as phenyl or naphthyl. May be.)

Examples of R ¹ include phenyl, 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl, and the like. Examples of R ³ O ⁻ include hydroxide ions, alcoholate ions, acetate ions, and acetylacetone ions.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  Among the above formulas (Chemical Formula 17), when M is selected from Li, Na, K, Be, Mg, Sr, Ba, Mn, Ni, Cu, and Zn, the effect of improving the catalytic activity is large and preferable. Of these, Li, Na, and Mg are particularly preferable.

  Examples of the metal salt compound of phosphorus constituting the polycondensation catalyst used in the present invention include lithium [(1-naphthyl) methylphosphonate ethyl], sodium [(1-naphthyl) methylphosphonate ethyl], magnesium bis [(1-naphthyl). ) Ethyl methylphosphonate], potassium [ethyl (2-naphthyl) methylphosphonate], magnesium bis [ethyl (2-naphthyl) methylphosphonate], lithium [ethyl benzylphosphonate], sodium [ethyl benzylphosphonate], magnesium bis [ Ethyl benzylphosphonate], beryllium bis [ethyl benzylphosphonate], strontium bis [ethyl benzylphosphonate], manganese bis [ethyl benzylphosphonate], sodium benzylphosphonate, magnesium bis [benzylphosphone] ], Sodium [ethyl (9-anthryl) methylphosphonate], magnesium bis [ethyl (9-anthryl) methylphosphonate], sodium [ethyl 4-hydroxybenzylphosphonate], magnesium bis [ethyl 4-hydroxybenzylphosphonate], Sodium [phenyl 4-chlorobenzylphosphonate], magnesium bis [ethyl 4-chlorobenzylphosphonate], sodium [methyl 4-aminobenzylphosphonate], magnesium bis [methyl 4-aminobenzylphosphonate], sodium phenylphosphonate Magnesium bis [ethyl phenylphosphonate], zinc bis [ethyl phenylphosphonate] and the like. Among these, lithium [ethyl (1-naphthyl) methylphosphonate], sodium [ethyl (1-naphthyl) methylphosphonate], magnesium bis [ethyl (1-naphthyl) methylphosphonate], lithium [ethyl benzylphosphonate], Sodium [ethyl benzylphosphonate], magnesium bis [ethyl benzylphosphonate], sodium benzylphosphonate and magnesium bis [benzylphosphonic acid] are particularly preferred.

Among the phosphorus compounds described above, a P compound having at least one P—OH bond is particularly preferable as the phosphorus compound in the present invention. In addition to particularly enhancing the physical properties improving effect of the polyester by containing these phosphorus compounds, the catalytic activity is improved by using these phosphorus compounds together with the Al compound used in the present invention during the polymerization of the polyester. The effect is seen greatly.
The phosphorus compound having at least one P—OH bond is not particularly limited as long as it is a phosphorus compound having at least one P—OH in the molecule. Among these phosphorus compounds, use of a phosphonic acid compound having at least one P—OH bond is preferable because of its great effect of improving the physical properties and improving the catalytic activity of the polyester.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  As the phosphorus compound having at least one P—OH bond constituting the polycondensation catalyst used in the present invention, if at least one selected from the compounds represented by the following general formula (Chemical Formula 18) is used, the physical property improving effect or The effect of improving the catalytic activity is large and preferable.

(In the formula (Chemical Formula 18), R ¹ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a hydrocarbon group having 1 to 50 carbon atoms. R ² represents , Hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group, n represents an integer of 1 or more, and the hydrocarbon group is an alicyclic structure such as cyclohexyl. And may contain an aromatic ring structure such as a branched structure or phenyl or naphthyl.)

Examples of R ¹ include phenyl, 1-naphthyl, 2-naphthyl, 9-anthryl, 4-biphenyl, 2-biphenyl, and the like. Examples of R ² include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, long-chain aliphatic group, phenyl group, naphthyl group, Examples thereof include a substituted phenyl group, a naphthyl group, and a group represented by —CH ₂ CH ₂ OH.

  Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  Examples of the phosphorus compound having at least one P—OH bond constituting the polycondensation catalyst used in the present invention include ethyl (1-naphthyl) methylphosphonate, (1-naphthyl) methylphosphonic acid, and (2-naphthyl) methylphosphonic acid ethyl. , Ethyl benzylphosphonate, benzylphosphonic acid, ethyl (9-anthryl) methylphosphonate, ethyl 4-hydroxybenzylphosphonate, ethyl 2-methylbenzylphosphonate, phenyl 4-chlorobenzylphosphonate, methyl 4-aminobenzylphosphonate , Ethyl 4-methoxybenzylphosphonate and the like. Of these, ethyl (1-naphthyl) methylphosphonate and ethyl benzylphosphonate are particularly preferred.

  A preferable phosphorus compound constituting the polycondensation catalyst used in the present invention includes a phosphorus compound represented by the chemical formula (Formula 19).

(In the formula (Chemical Formula 19), R ¹ represents a hydrocarbon group having ¹ to 49 carbon atoms, or a hydrocarbon group having ¹ to 49 carbon atoms including a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and R ² , R ³ each independently represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, which has an alicyclic structure, a branched structure or an aromatic ring structure. May be included.)

More preferably, at least one of R ¹ , R ² and R ^{3 in} the chemical formula (Formula 19) is a compound containing an aromatic ring structure.

  Specific examples of these phosphorus compounds are shown below.

  Moreover, since the phosphorus compound which comprises the polycondensation catalyst used by this invention has a large effect, since the thing with larger molecular weight is hard to be distilled off at the time of superposition | polymerization, it is preferable.

  The phosphorus compound constituting the polycondensation catalyst used in the present invention is preferably a phosphorus compound having a phenol moiety in the same molecule. In addition to enhancing the physical properties of polyester by containing a phosphorus compound having a phenol moiety in the same molecule, the effect of increasing catalytic activity by using a phosphorus compound having a phenol moiety in the same molecule during polyester polymerization Is larger, and therefore the polyester productivity is excellent.

  The phosphorus compound having a phenol moiety in the same molecule is not particularly limited as long as it is a phosphorus compound having a phenol structure, but a phosphonic acid compound, a phosphinic acid compound, a phosphine oxide compound having a phenol moiety in the same molecule. When one or more compounds selected from the group consisting of a compound, a phosphonous acid compound, a phosphinic acid compound, and a phosphine compound are used, the effect of improving the physical properties of the polyester and the effect of improving the catalytic activity are greatly preferred. Among these, when a phosphonic acid compound having one or two or more phenol moieties in the same molecule is used, the effect of improving the physical properties of the polyester and the effect of improving the catalytic activity are particularly large and preferable.

  As a phosphorus compound which has the phenol part which comprises the polycondensation catalyst used by this invention in the same molecule, the compound represented by the following general formula (Formula 26)-(Formula 28) is preferable.

(In the formulas (Chemical Formula 26) to (Chemical Formula 28), R ¹ is a carbon having 1 to 50 carbon atoms including a phenol part, a substituent such as a hydroxyl group, a halogen group, an alkoxyl group, or an amino group, and a phenol part. R ⁴ , R ⁵ and R ⁶ each independently represents a substituent such as hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, a halogen group, an alkoxyl group or an amino group. Represents a hydrocarbon group having 1 to 50 carbon atoms, R ² and R ³ each independently represent hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group, and the like. Represents a hydrocarbon group, provided that the hydrocarbon group may contain a branched structure, an alicyclic structure such as cyclohexyl, or an aromatic ring structure such as phenyl or naphthyl, and the ends of R ² and R ⁴ are bonded to each other. May be.)

  Examples of phosphorus compounds having a phenol moiety constituting the polycondensation catalyst used in the present invention in the same molecule include p-hydroxyphenylphosphonic acid, dimethyl p-hydroxyphenylphosphonate, diethyl p-hydroxyphenylphosphonate, p -Diphenyl phenyl phosphonate, bis (p-hydroxyphenyl) phosphinic acid, methyl bis (p-hydroxyphenyl) phosphinate, phenyl bis (p-hydroxyphenyl) phosphinate, p-hydroxyphenylphenylphosphinic acid, p-hydroxy Methyl phenylphenylphosphinate, phenyl p-hydroxyphenylphenylphosphinate, p-hydroxyphenylphosphinic acid, methyl p-hydroxyphenylphosphinate, p-hydroxyphenylphosphinic acid Nyl, bis (p-hydroxyphenyl) phosphine oxide, tris (p-hydroxyphenyl) phosphine oxide, bis (p-hydroxyphenyl) methylphosphine oxide, and compounds represented by the following formulas (Chemical 29) to (Chemical 32) Etc. Among these, a compound represented by the following formula (Chemical Formula 31) and dimethyl p-hydroxyphenylphosphonate are particularly preferable.

  As a compound represented by the above formula (Chemical Formula 31), SANKO-220 (manufactured by Sanko Co., Ltd.) can be used.

  Among the phosphorus compounds having a phenol moiety constituting the polycondensation catalyst used in the present invention in the same molecule, at least one selected from a specific phosphorus metal salt compound represented by the following general formula (Formula 33) is particularly preferable. preferable.

(In Formula (Chemical Formula 33), R ¹ and R ² each independently represent hydrogen and a hydrocarbon group having 1 to 30 carbon atoms. R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, or R ⁴ represents a hydrocarbon group having 1 to 50 carbon atoms including an alkoxyl group, R ⁴ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, an alkoxyl group, or a carbonyl group including carbonyl. Examples of R ⁴ O ⁻ include hydroxide ion, alcoholate ion, acetate ion, acetylacetone ion, etc. l represents an integer of 1 or more, m represents 0 or an integer of 1 or more, and l + m represents M is an (l + m) -valent metal cation, n is an integer of 1 or more, and the hydrocarbon group is an alicyclic structure such as cyclohexyl or a branched structure, or an aromatic ring structure such as phenyl or naphthyl. May be included.)

  Among these, at least one selected from compounds represented by the following general formula (Formula 34) is preferable.

(In the formula (Chemical Formula 34), M ^{n +} represents an n-valent metal cation. N represents 1, 2, 3 or 4.)

  Among the above formulas (Chemical Formula 33) or (Chemical Formula 34), when M is selected from Li, Na, K, Be, Mg, Sr, Ba, Mn, Ni, Cu, Zn, the catalytic activity is improved. The effect is large and preferable. Of these, Li, Na, and Mg are particularly preferable.

  Specific phosphorus metal salt compounds constituting the polycondensation catalyst used in the present invention include lithium [3,5-di-tert-butyl-4-hydroxybenzylphosphonate], sodium [3,5-di- tert-butyl-4-hydroxybenzylphosphonic acid ethyl], sodium [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid], potassium [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid] Acid ethyl], magnesium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ethyl], magnesium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid], beryllium bis [ Methyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], strontium bis [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], Barium bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate phenyl], manganese bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl], nickel bis [3,5 -Ethyl di-tert-butyl-4-hydroxybenzylphosphonate], copper bis [3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl], zinc bis [3,5-di-tert-butyl -Ethyl 4-hydroxybenzylphosphonate] and the like. Among these, lithium [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], sodium [ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate], magnesium bis [ Ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate] is particularly preferred.

  Among the phosphorus compounds having the phenol moiety constituting the polycondensation catalyst used in the present invention in the same molecule, selected from specific phosphorus compounds having at least one P-OH bond represented by the following general formula (Formula 35) At least one of these is particularly preferred.

(In Formula (Chemical Formula 35), R ¹ and R ² each independently represent hydrogen and a hydrocarbon group having 1 to 30 carbon atoms. R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group, or Represents a C1-C50 hydrocarbon group containing an alkoxyl group, n represents an integer of 1 or more, and the hydrocarbon group includes an alicyclic structure such as cyclohexyl, a branched structure, and an aromatic ring structure such as phenyl or naphthyl. May be.)

  Among these, at least one selected from compounds represented by the following general formula (Formula 36) is preferable.

(In the formula (Chemical Formula 36), R ³ represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydroxyl group or an alkoxyl group containing 1 to 50 carbon atoms. The hydrocarbon group is a fatty acid such as cyclohexyl. (It may contain a ring structure, a branched structure, or an aromatic ring structure such as phenyl or naphthyl.)

Examples of R ³ include hydrogen, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, long-chain aliphatic group, phenyl group, naphthyl group, Examples thereof include a substituted phenyl group, a naphthyl group, and a group represented by —CH ₂ CH ₂ OH.

  Specific phosphorus compounds having at least one P-OH bond constituting the polycondensation catalyst used in the present invention include ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,5-di- Methyl tert-butyl-4-hydroxybenzylphosphonate, isopropyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, phenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3 , 5-di-tert-butyl-4-hydroxybenzylphosphonic acid octadecyl, 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid, and the like. Of these, ethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and methyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate are particularly preferred.

  Among the phosphorus compounds having a phenol moiety constituting the polycondensation catalyst used in the present invention in the same molecule, at least one phosphorus compound selected from specific phosphorus compounds represented by the following general formula (Formula 37) is preferable.

(In the above formula (Chemical Formula 37), R ¹ and R ² each independently represent hydrogen and a hydrocarbon group having 1 to 30 carbon atoms. R ³ and R ⁴ each independently represent hydrogen and carbon atoms having 1 to 50 carbon atoms. Represents a hydrocarbon group having 1 to 50 carbon atoms including a hydrogen group, a hydroxyl group or an alkoxyl group, n represents an integer of 1 or more, and the hydrocarbon group is an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic such as phenyl or naphthyl. It may contain a ring structure.)

  Among the above general formulas (Chemical Formula 37), it is preferable to use at least one selected from the compounds represented by the following General Formula (Chemical Formula 38) because the effect of improving the physical properties of the polyester and the effect of improving the catalytic activity are high.

(In the above formula (Chemical Formula 38), R ³ and R ⁴ each independently represents hydrogen, a hydrocarbon group having 1 to 50 carbon atoms, a hydrocarbon group having 1 to 50 carbon atoms including a hydroxyl group or an alkoxyl group. The group may contain an alicyclic structure such as cyclohexyl, a branched structure, or an aromatic ring structure such as phenyl or naphthyl.)

Examples of R ³ and R ⁴ include short chain aliphatic groups such as hydrogen, methyl and butyl groups, long chain aliphatic groups such as octadecyl, phenyl groups, naphthyl groups, substituted phenyl groups and naphthyl groups. An aromatic group such as a group, a group represented by —CH ₂ CH ₂ OH, and the like.

  Specific phosphorus compounds constituting the polycondensation catalyst used in the present invention include diisopropyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,5-di-tert-butyl-4-hydroxybenzyl Examples include di-n-butyl phosphonate, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diphenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate. Of these, dioctadecyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and diphenyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate are particularly preferred.

  Among the phosphorus compounds having a phenol moiety constituting the polycondensation catalyst used in the present invention in the same molecule, particularly desirable compounds in the present invention are selected from compounds represented by chemical formulas (Chemical Formula 39) and (Chemical Formula 40). At least one P compound.

  As the compound represented by the above chemical formula (Chemical Formula 39), Irganox 1222 (manufactured by Ciba Specialty Chemicals) is commercially available, and as the compound represented by the chemical formula (Chemical Formula 40), Irganox 1425 (Ciba Specialty Chemical) is available. Chemicals) is commercially available and can be used.

  Phosphorus compounds have been known as heat stabilizers for polyesters, but it has not been known so far that even when these compounds are used in combination with conventional metal-containing polyester polymerization catalysts, melt polymerization is greatly promoted. It was. Actually, when a polyester is melt polymerized using a Sb compound, Ti compound, Sn compound or Ge compound, which is a typical catalyst for polyester polymerization, as a polymerization catalyst, the P compound used in the present invention is substantially added. It is not observed that polymerization is accelerated to a useful level.

  As described above, the amount of the phosphorus compound used in the production of the polyester used in the present invention is 0.0001 to 0.1 mol with respect to the number of moles of all constituent units of the polycarboxylic acid component of the obtained polyester. % Is preferable, and 0.005 to 0.05 mol% is more preferable.

In the present invention, by using the phosphorus compound in combination, a catalyst exhibiting a sufficient catalytic effect can be obtained even when the amount of addition as Al in the polyester polymerization catalyst is small. When the addition amount of the phosphorus compound is less than 0.0001 mol%, the addition effect may not be exhibited, and when added over 0.1 mol%, the catalytic activity as a polyester polymerization catalyst may be reduced. There is a tendency of the change depending on the amount of Al used.

As a metal compound of the polycondensation catalyst, in addition to Al, at least one compound selected from Ge, Sb, or Ti compounds may be used in combination.
As the Ge compound, amorphous germanium dioxide, crystalline germanium dioxide powder or ethylene glycol slurry, a solution in which crystalline germanium dioxide is heated and dissolved in water, or a solution in which ethylene glycol is added and heat-treated are used. In particular, in order to obtain the polyester used in the present invention, it is preferable to use a solution in which germanium dioxide is dissolved by heating in water, or a solution in which ethylene glycol is added and heated. In addition, compounds such as germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, and germanium phosphite can also be used.

Examples of the Sb compound include antimony trioxide, antimony acetate, antimony tartrate, antimony potassium tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, and triphenylantimony.
Examples of Ti compounds include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate, and partial hydrolysates thereof, titanium acetate, titanyl oxalate, titanyl oxalate, titanyl oxalate Sodium, titanyl oxalate, titanyl calcium oxalate, titanyl succinate, titanyl succinate, titanium trimellitic acid, titanium sulfate, titanium chloride, titanium halide hydrolyzate, titanium oxalate, titanium fluoride, titanium hexafluoride Potassium acid, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, titanium acetylacetonate, titanium with hydroxy polyvalent carboxylic acid or nitrogen-containing polyvalent carboxylic acid A phosphorus compound is reacted with a complex compound, a composite oxide composed of titanium and silicon or zirconium, a reaction product of titanium alkoxide and a phosphorus compound, or a reaction product of titanium alkoxide and an aromatic polycarboxylic acid or its anhydride. The reaction product obtained by the above.

  In combination with aluminum compounds, other polycondensation catalysts such as antimony compounds, germanium compounds, titanium compounds, etc., within the range of additions where these components do not cause problems with the polyester properties, workability, color tone, etc. Use in the presence of coexistence is effective and preferable in improving productivity by shortening the polymerization time.

However, the antimony compound can be added so that the amount of antimony atoms remaining in the polyester obtained by polymerization is 50 ppm or less. A more preferable residual amount is 30 ppm or less. When the remaining amount of antimony exceeds 50 ppm, metal antimony is precipitated, and darkening and foreign matter are generated in the polyester, which is not preferable.
The germanium compound can be added so that the amount of germanium atoms remaining in the polyester obtained by polymerization is 30 ppm or less. A more preferable residual amount is 20 ppm or less. If the remaining amount of germanium exceeds 30 ppm, it is not preferable because it is disadvantageous in terms of cost.
Further, the titanium compound can be added so that the residual amount of Ti in the produced polymer is 10 ppm or less. A more preferable residual amount is 5 ppm or less. If the Ti residual amount exceeds 10 ppm or more, it is not preferable because it is markedly colored.

  The polycondensation catalyst used in the present invention can be added to the reaction system at any stage of the polymerization reaction. For example, it can be added to the reaction system before the start of the esterification reaction or transesterification reaction and at any stage during the reaction or immediately before the start of the polycondensation reaction or during the reaction. In particular, aluminum or a compound thereof is preferably added immediately before the start of the polycondensation reaction.

  The addition method of the polycondensation catalyst used in the present invention may be in the form of powder or neat, or may be added in the form of a slurry or solution of a solvent such as ethylene glycol, and is particularly limited. Not. Further, aluminum metal or a compound thereof and other components, preferably a phosphorus compound used in the present invention, may be added as a mixture or complex mixed in advance, or these may be added separately. Aluminum metal or a compound thereof and other components, preferably a phosphorus compound, may be added to the polymerization system at the same addition time, and each component may be added at different addition times.

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

Further, as the cooling water at the time of forming the melt polycondensed polyester into chips, it is preferable to use cooling water satisfying at least one of the following formulas (4) to (7), and more preferably (4) to ( 7) It is most preferred to use water that satisfies all of the equations.
Na ≦ 1.0 (ppm) (4) Formula
Mg ≦ 1.0 (ppm) (5) Formula
Si ≦ 2.0 (ppm) (6) Formula
Ca ≦ 1.0 (ppm) (7) Formula

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

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

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

Next, solid phase polymerization is performed under an inert gas atmosphere or under reduced pressure at an optimum temperature for the melt polycondensed polyester so that the increase in intrinsic viscosity due to solid phase polymerization is 0.10 deciliter / gram or more. . For example, in the case of PET, the upper limit of the solid phase polymerization temperature is preferably 215 ° C. or lower, more preferably 210 ° C. or lower, particularly 208 ° C. or lower, and the lower limit is 190 ° C. or higher, preferably 195 ° C. or higher. is there.
It is preferable that the chip temperature is about 70 ° C. or lower, preferably 60 ° C. or lower, more preferably 50 ° C. or lower, within about 30 minutes, preferably within 20 minutes, more preferably within 10 minutes after completion of solid phase polymerization.

The polyester resin of the present invention contains the following polyester A and polyester B having ethylene terephthalate as a main repeating unit as main components, and the crystallization temperature of polyester A when it cools and the crystallization of polyester B when it cools A polyester resin having a temperature difference of 20 ° C. or less is preferable.
Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.80 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at the time of temperature increase measured by DSC is 140 to 180 ° C., and the crystallization temperature at the time of temperature decrease is Polyester that is 160-200 ° C.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.95 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at the time of temperature increase measured by DSC is 140 to 180 ° C., and the crystallization temperature at the time of temperature decrease is Polyester that is 160-200 ° C.

Here, the DSC measurement is performed using a molded plate (2 mm thick) injection-molded at 290 ° C. by the method described later.
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, it is also possible to use two types of polyesters that differ only in IV as the polyester A and polyesters that are mixed so as to have the above-described composition ratio using one type of polyester as the polyester B.

  Further, the difference between the crystallization temperature when the temperature of the polyester A is lowered and the crystallization temperature when the temperature of the polyester B is lowered is preferably within 15 ° C, more preferably within 10 ° C, and particularly preferably within 8 ° C. When the difference in the crystallization temperature at the time of temperature drop exceeds 20 ° C., the transparency of the obtained molded product becomes very poor, the crystallization speed fluctuation at the time of crystallization of the plug portion becomes large, and the dimensional accuracy is poor. It is a problem. In addition, the lower limit of the difference in crystallization temperature when the temperature is lowered is 2 ° C. Below this, the difference in effect becomes unclear. Here, when the polyester resin of the present invention is composed of two or more kinds of polyester, the difference in the crystallization temperature at the time of temperature decrease is the value of the polyester having the highest temperature crystallization temperature and the lowest temperature crystallization temperature. The difference in the value of polyester with

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, The crystallization temperature at the time of temperature rise is preferably 145 to 177 ° C, more preferably 150 to 175 ° C, and the crystallization temperature at the time of temperature drop is preferably 162 to 190 ° C, more preferably 165 to 180 ° C. 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, if it exceeds 0.80 deciliter / gram, the effect of reducing acetaldehyde is lowered. On the other hand, when the acetaldehyde content exceeds 10 ppm, the flavor retention of the obtained molded article is deteriorated, which causes a problem. On the other hand, in a method that is economically profitable, the lower limit of the acetaldehyde content is 1 ppm. Further, when the crystallization temperature of polyester A 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. If the crystallization temperature of polyester A when the temperature is lowered is less than 160 ° C., the effect of improving the crystallization speed of the plug portion is deteriorated, and if it exceeds 200 ° C., the transparency of the molded article 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, The crystallization temperature at the time of temperature rise is preferably 145 to 177 ° C, more preferably 150 to 175 ° C, and the crystallization temperature at the time of temperature drop is preferably 162 to 190 ° C, more preferably 165 to 180 ° C. 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, heat generation during molding becomes intense and the effect of reducing acetaldehyde becomes low. On the other hand, when the acetaldehyde content exceeds 10 ppm, the flavor retention of the obtained molded article is deteriorated, which causes a problem. On the other hand, in a method that is economically profitable, the lower limit of the acetaldehyde content is 1 ppm. Moreover, when the crystallization temperature at the time of temperature rising of polyester B is less than 140 degreeC, the transparency of a molded object will worsen, and when it exceeds 180 degreeC, the crystallization speed improvement effect of a plug part will worsen and it is a problem. If the crystallization temperature of the polyester B when the temperature is lowered is less than 160 ° C., the effect of improving the crystallization rate of the plug portion becomes worse, and if it exceeds 200 ° C., the transparency of the molded article becomes worse.

  By using the polyester resin 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 ( For example, it is possible to obtain a hollow molded body 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.

  Further, when the polyester of the present invention is a polyester whose main repeating unit is ethylene-2,6-naphthalate (hereinafter sometimes abbreviated as PEN), the intrinsic viscosity of at least two kinds of polyesters is 0. It is selected from polyesters in the range of 40 to 0.80 deciliter / gram, preferably 0.42 to 0.75 deciliter / gram, more preferably 0.45 to 0.70 deciliter / gram. When the IV is less than 0.40 deciliter / gram, the mechanical properties of the obtained molded article are poor. In addition, when it exceeds 0.80 deciliter / gram, it becomes necessary to increase the resin temperature at the time of melting by a molding machine or the like, so that it is accompanied by thermal decomposition, increasing the number of aldehydes such as acetaldehyde, and the molded product becomes yellow Problems such as coloring occur.

Furthermore, when the polyester of the present invention is PEN, it contains the following polyester C and polyester D as main components, and there is a difference between the crystallization temperature when the polyester C is cooled and the crystallization temperature when the polyester D is cooled. The polyester resin is preferably within 18 ° C.
Polyester C: Polyester having an intrinsic viscosity IV _C of 0.40 to 0.70 deciliter / gram, a crystallization temperature at the time of temperature increase measured by DSC of 180 to 235 ° C., and a crystallization temperature at the time of temperature decrease of 160 to 210 ° C. .
Polyester D: Polyester having an intrinsic viscosity IV _D of 0.50 to 0.80 deciliter / gram, a crystallization temperature of 180 to 235 ° C. during temperature rise measured by DSC, and a crystallization temperature of 160 to 210 ° C. during temperature fall .

  When the polyester of the present invention is a polyester whose main structural unit is 1,3-propylene terephthalate, the intrinsic viscosity of at least two kinds of polyesters is 0.50 to 1.00 deciliter / gram, Preferably, polyesters in the range of 0.55 to 0.90 deciliters / gram, more preferably 0.60 to 0.85 deciliters / gram are selected within the scope of the present invention. When the intrinsic viscosity is less than 0.50 deciliter / gram, the mechanical properties of the obtained molded article are deteriorated, which is a problem. The upper limit of the intrinsic viscosity is 1.00 deciliter / gram. If the upper limit is exceeded, the resin temperature at the time of molding becomes high, the thermal decomposition becomes severe, the molecular weight decreases drastically, and the generation of aldehydes is intense. In addition, problems such as yellowing occur.

  When the polyester resin of the present invention contains at least two kinds of polyesters as the main components as described above, the type and amount of the polycondensation catalyst described above, melt polycondensation, solid-state polymerization conditions, etc. are appropriately controlled. Can be manufactured by. It can also be obtained by a method of giving an impact to the polyester chip thus obtained, and a method of blending a polyolefin resin, particularly polyethylene, polyamide resin, polyoxymethylene resin, etc. as will be described later.

Moreover, it is preferable that the thermal stability parameter (TS) of the said polyester A and polyester B which concerns on this invention satisfy | fills following (1) Formula.
TS <0.30 (1) Formula (TS is a melting test (1 g of a polyester resin chip is placed in a glass test tube and vacuum dried at 130 ° C. for 12 hours, and then melted at 300 ° C. for 2 hours in a non-circulating nitrogen atmosphere) It is a value obtained by measuring the intrinsic viscosity before and after) and using the following formula.
TS = 0.245 {[IV] _f2 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f2 indicate intrinsic viscosities (unit: deciliter / gram) before and after the melting test, respectively. )
The non-circulating nitrogen atmosphere means a non-circulating nitrogen atmosphere. For example, a glass test tube containing a resin chip is connected to a vacuum line, and the pressure is reduced to 100 Torr after repeating depressurization and nitrogen filling five or more times. Nitrogen is sealed and sealed.

  The thermal stability parameter (TS) of the polyester is more preferably 0.25 or less, further preferably 0.20 or less, and particularly preferably 0.15 or less. When TS of at least one kind of polyester constituting the polyester resin is 0.30 or more, since the thermal stability of the polyester resin is poor, the decrease in the intrinsic viscosity during molding is large, and the transparency of the molded product is deteriorated, Moreover, the purpose cannot be achieved because the production of aldehydes such as acetaldehyde increases. Needless to say, it is most desirable that the thermal stability parameter (TS) of all the polyesters constituting the polyester resin is less than 0.30. A polyester resin having such characteristics can be obtained, for example, by managing the remaining amount of the polycondensation catalyst used as described above.

Moreover, it is preferable that the thermal oxidation stability parameter (TOS) of the polyester A and the polyester B according to the present invention satisfy the following formula (2).
TOS <0.20 (2) (TOS is a heat test (polyester resin chips are frozen and pulverized to a powder of 20 mesh or less, vacuum-dried at 130 ° C. for 12 hours, 0.3 g is put in a glass test tube, This is a value obtained by measuring the intrinsic viscosity before and after vacuum drying at 70 ° C. for 12 hours and then heating at 230 ° C. for 15 minutes in air dried with silica gel and using the following formula.
TOS = 0.245 {[IV] _f1 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f1 indicate intrinsic viscosities (unit: deciliter / gram) before and after the heating test, respectively. )
In addition, as a method of heating in the air dried with silica gel, for example, a method of heating in a dry air by attaching a drying tube containing silica gel to the upper portion of the glass test tube can be used.

  The thermal oxidation stability parameter (TOS) of the polyester is preferably less than 0.10, more preferably 0.09 or less, and even more preferably 0.08 or less. When the TOS of at least one kind of polyester constituting the polyester resin is 0.20 or more, the thermal oxidation stability of the polyester resin is poor, so that the decrease in the intrinsic viscosity during heat drying or molding in the presence of oxygen increases. The object cannot be achieved because the transparency of the molded article deteriorates and the production of aldehydes such as acetaldehyde increases. Furthermore, it is most desirable that the thermal oxidation stability parameter (TOS) of all polyesters constituting the polyester resin is less than 0.20. A polyester resin having such characteristics can be obtained, for example, by managing the remaining amount of the polycondensation catalyst used as described above. Further, by avoiding the use of a metal compound that promotes oxidation of polyester such as Co, or by maintaining the content of dialkylene glycol copolymerized with polyester at 7 mol% or less as described later, (2 It is possible to satisfy the thermal oxidation stability (TOS) of the formula (1).

Moreover, it is preferable that the hydrolysis resistance parameter (HS) of the polyester A and the polyester B according to the present invention satisfy the following formula (3).
HS <0.10 (3) Formula (HS is a hydrolysis test (freeze-pulverized polyester resin chips are made into a powder of 20 mesh or less, vacuum-dried at 130 ° C. for 12 hours) 1 g of pure water is put into a beaker with 100 ml of pure water. It is a value obtained by measuring the intrinsic viscosity before and after stirring for 6 hours under the condition of heating and pressurizing at 130 ° C. in a closed system and using the following formula.
HS = 0.245 {[IV] _f3 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f3 indicate intrinsic viscosities (unit: deciliter / gram) before and after the hydrolysis test, respectively. )
In addition, the beaker used for the measurement of HS uses what does not elute acid and alkali. Specifically, it is preferable to use a stainless steel beaker or a quartz beaker.

  The hydrolysis resistance parameter (HS) of the polyester is preferably 0.095 or less, more preferably 0.09 or less, and still more preferably 0.085 or less. When the polyester HS is 0.10 or more, the hydrolysis stability of the polyester resin is poor, resulting in a large decrease in the intrinsic viscosity at the time of molding, resulting in poor transparency of the molded product, and the use of aldehydes such as acetaldehyde. The purpose cannot be achieved due to the generation. A polyester resin having such characteristics can be obtained, for example, by managing the remaining amount of the polycondensation catalyst used as described above.

By using polyester that retains the above-mentioned characteristics such as thermal stability, thermal degradation during melt molding is effectively suppressed without deactivating or removing the catalyst, resulting in excellent thermal stability and stable thermal oxidation. It is preferable because it can provide a polyester resin having excellent properties, excellent hydrolysis resistance, excellent color tone, and less defects and excellent transparency.
TS, TOS and HS are measured by the method described in detail later.

  The content of dialkylene glycol copolymerized in the polyester of the present invention is 0.5 to 7.0 mol%, preferably 1.0 to 6.0 mol% of the glycol component constituting the polyester. Preferably it is 1.5-5.0 mol%, More preferably, it is 1.5-4.0 mol%. When the amount of dialkylene glycol exceeds 7.0 mol%, the heat stability is deteriorated, the decrease in molecular weight at the time of molding is increased, and the increase in the content of aldehydes is increased. Further, in order to produce a polyester having a dialkylene glycol content of less than 0.5 mol%, it is necessary to select non-economic production conditions as transesterification conditions, esterification conditions or polymerization conditions, and the cost is not suitable. . Here, the dialkylene glycol copolymerized in the polyester, for example, in the case of a polyester whose main structural unit is ethylene terephthalate, is a diethylene glycol (hereinafter referred to as “DEG”) by-produced during the production from ethylene glycol, which is glycol. In the case of a polyester having 1,3-propylene terephthalate as a main structural unit, it is produced from 1,3-propylene glycol, which is a glycol, at the time of production. Of di (1,3-propylene glycol) (or bis (3-hydroxypropyl) ether) produced as a by-product, di (1,3-propylene glycol (hereinafter referred to as DPG) copolymerized with the polyester may be used. ).

  In particular, the amount of diethylene glycol copolymerized with the polyester whose main repeating unit is composed of ethylene terephthalate is 1.0 to 5.0 mol%, preferably 1.3 to 4.5 mol, of the glycol component constituting the polyester. %, More preferably 1.5 to 4.0 mol%. When the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability is deteriorated, the decrease in molecular weight becomes large at the time of molding, and the increase in the acetaldehyde content and the formaldehyde content becomes large. Moreover, when diethylene glycol content is less than 1.0 mol%, the transparency of the obtained molded object worsens.

  In addition, since diethylene glycol and triethylene glycol (hereinafter sometimes referred to as “TEG”) are partially by-produced from ethylene glycol during the polymerization reaction, a predetermined amount of DEG and / or TEG and its ester-forming derivative is used. In addition to the case where is used as a polymerization raw material, the content of the DEG component and / or the TEG component can be controlled only by appropriately selecting reaction conditions, additives and the like. Examples of the additive include tertiary amines such as triethylamine, tri-n-butylamine and benzyldimethylamine, and quaternary hydroxides such as tetraethylammonium hydroxide, tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide. A small amount of a basic compound such as ammonium and lithium carbonate, sodium carbonate, potassium carbonate, or sodium acetate can be added to suppress the formation of DEG and / or TEG. On the other hand, if a small amount of an inorganic acid such as sulfuric acid is added to the polymerization raw material, the production of DEG and / or TEG can be promoted and the content can be increased. If necessary, these additives for controlling the production amount of DEG and / or TEG are usually used in the range of 0.001 to 10% by weight, preferably 0.005 to 1% by weight of the total polymerization raw material. May be.

  The content of aldehydes such as acetaldehyde in the polyester resin of the present invention is 50 ppm or less, preferably 30 ppm or less, more preferably 10 ppm or less. When the aldehyde content exceeds 50 ppm, the effect of maintaining the flavor of the contents such as a molded article formed from such polyester is deteriorated. Further, these lower limits are preferably 0.1 ppb from the viewpoint of production. Here, the aldehydes are acetaldehyde in the case where the polyester is a polyester having ethylene terephthalate as a main constituent unit or a polyester having ethylene naphthalate as a main constituent unit, and a polyester having 1,3-propylene terephthalate as a main constituent unit. In the case of allyl aldehyde.

  In particular, when the polyester resin of the present invention is composed of a polyester having ethylene terephthalate as a main repeating unit, and this is used as a material for containers for low flavor beverages such as mineral water, the polyester resin of the present invention. The acetaldehyde content of is desirably 10 ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less, and most preferably 4 ppm or less. When the content of acetaldehyde exceeds 10 ppm, the odor and taste of the contents of the molded product molded from this polyester resin are adversely affected, resulting in a problem that the commercial value is lost.

  The content of the cyclic ester oligomer of the polyester resin of the present invention is 70% or less, preferably 60% or less, more preferably 50% of the content of the cyclic ester oligomer contained in the melt polycondensation polyester prepolymer of the polyester. Hereinafter, it is particularly preferably 35% or less. Here, the polyester generally contains cyclic ester oligomers having various degrees of polymerization, but the cyclic ester oligomer referred to in the present invention is the cyclic ester oligomer having the highest content among the cyclic ester oligomers contained in the polyester. An ester oligomer means, for example, a cyclic trimer in the case of a polyester having ethylene terephthalate as a main repeating unit. In the case of PET, in which the polyester is a typical polyester having ethylene terephthalate as the main structural unit, the content of the cyclic trimer of the melt polycondensed polyester prepolymer is about 1.0% by weight. The content of the cyclic trimer of the resin is 0.70% by weight or less, preferably 0.60% by weight or less, more preferably 0.50% by weight or less, and particularly preferably 0.35% by weight or less. 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 is 0.70% by weight or more, the adhesion of the oligomer to the gas exhaust port of the preformed mold or the heat fixing mold surface after the stretch molding increases rapidly, Transparency of the obtained hollow molded body or the like is extremely deteriorated.

  In addition, when the polyester resin of the present invention is a polyester having ethylene terephthalate as a main repeating unit and is used for molding a highly heat-resistant hollow molded body, heat treatment is performed in a heating mold. The content of the monomer is 0.50% by weight or less, preferably 0.40% by weight or less, more preferably 0.35% by weight or less.

  Examples of the method for setting the content of the cyclic ester oligomer of the polyester resin of the present invention to 70% or less of the content of the cyclic ester oligomer contained in the polyester melt polycondensation polyester prepolymer include, for example, a melt polycondensation polyester prepolymer. Examples include a solid-phase polymerization method, a method of treating a melt polycondensation polymer with a heated inert gas containing the polymer component glycol, a method of treating with a solvent, and a method of combining these methods as appropriate. .

Further, the increase amount of the cyclic ester oligomer when the polyester resin of the present invention is melted at a temperature of 290 ° C. for 60 minutes is 0.40% by weight or less, preferably 0.30% by weight or less, more preferably 0.10% by weight. The following is preferable. When the amount of increase in cyclic ester oligomer when melted at 290 ° C for 60 minutes exceeds 0.40% by weight, the amount of cyclic ester oligomer increases when the molding resin melts, and the oligomer adheres to the surface of the heated mold during continuous molding. However, there is a problem that the transparency of the obtained molded body such as a hollow molded body is extremely deteriorated, and a great amount of labor and time are required for cleaning the mold. Moreover, the lower limit of the cyclic ester oligomer increase amount is about 0.01% by weight, and even if the lower limit is decreased below this, the economic effect on the above problems is very small.
When the polyester resin of the present invention is a polyester having ethylene terephthalate as a main repeating unit, the cyclic ester oligomer is a cyclic trimer as described above. The increase amount of the cyclic trimer when melted at 290 ° C. for 60 minutes is preferably 0.40% by weight or less.
The polyester resin of the present invention having a cyclic ester oligomer increase of 0.40% by weight or less when melted at a temperature of 290 ° C. for 60 minutes is a polyester polycondensation catalyst obtained after melt polycondensation or after solid-phase polymerization. It can be manufactured by deactivation treatment.

Examples of the method of deactivating the polycondensation catalyst of the polyester resin include a method of contacting the polyester chip with water, water vapor or water vapor-containing gas after melt polycondensation or after solid phase polymerization.
In order to achieve the above object, a method of contacting the polyester chip with water, water vapor or water vapor-containing gas will be described below.
Examples of the hot water treatment method include a method of immersing in water and a method of applying water on the chip with a shower. The treatment time is 5 minutes to 2 days, preferably 10 minutes to 1 day, more preferably 30 minutes to 10 hours, and the water temperature is 20 to 180 ° C., preferably 40 to 150 ° C., more preferably 50 to 120 ° C.

Although the method of performing water treatment industrially is illustrated below, it is not limited to this. The treatment method may be either a continuous method or a batch method, but the continuous method is preferred for industrial use.
A silo-type treatment tank is used when water-treating polyester chips in a batch system. That is, the polyester chip is received in a silo and treated with water in a batch system. Alternatively, polyester chips can be received in a rotating cylindrical treatment tank, and water treatment can be performed while rotating to make contact with water more efficient.
In the case where the polyester chips are water-treated in a continuous manner, the polyester chips can be continuously or intermittently received in the tower-type treatment tank from the upper part and water-treated.

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

Although the method of performing the contact treatment of granular polyester, water vapor | steam, or water vapor containing gas industrially below is illustrated, it is not limited to this. The processing method may be either a continuous method or a batch method.
When a polyester chip is contact-treated with water vapor in a batch system, a silo type processing apparatus can be used. That is, a polyester chip is received into a silo, and a contact process is performed by supplying steam or a steam-containing gas in a batch manner. Alternatively, the granular polyester is received in a rotating cylindrical contact processing apparatus, and contact processing can be performed while rotating to make contact more efficient.
In the case where the polyester chips are continuously contacted with water vapor, the granular polyester can be continuously received from the upper part in a tower-type processing apparatus, and the water vapor can be continuously supplied in parallel flow or countercurrent to be contacted with water vapor.
As described above, when treated with water or water vapor, the granular polyester is drained with a draining device such as a vibrating sieve or a Simon Carter as necessary, and transferred to the next drying step.

For drying the polyester chip that has been contact-treated with water or water vapor, a commonly used polyester drying treatment can be used. As a continuous drying method, a hopper type ventilation dryer is generally used in which a polyester chip is supplied from the upper part and a drying gas is supplied from the lower part. As a method of reducing the amount of dry gas and drying efficiently, a rotating disk type heating type continuous dryer is used, and heating steam, heating medium, etc. are supplied to the rotating disk and external jacket while a small amount of drying gas is vented. The polyester chips can be indirectly heated and dried.
As a dryer for drying in a batch system, a double cone type rotary dryer is used, and it can be dried under vacuum or under a vacuum with a small amount of drying gas aerated. Alternatively, drying may be performed while ventilating a dry gas under atmospheric pressure.
As the dry gas, atmospheric air may be used, but dry nitrogen and dehumidified air are preferable from the viewpoint of preventing molecular weight reduction due to hydrolysis or thermal oxidative decomposition of polyester.

  By subjecting the polyester resin to water or steam treatment as described above, the amount of oligomer increase after the polyester resin is heated and melted to a temperature of 290 ° C. can be suppressed.

  Aldehyde such as acetaldehyde or the like because when polyesters with greatly different molecular weights are injection-molded and melt-mixed, the low-molecular-weight component improves the fluidity of the mixed melt and suppresses the actual temperature rise of the melt. It is estimated that the occurrence of varieties is suppressed. When the catalyst is deactivated, the transesterification reaction between the mixed polyesters is suppressed, so there is almost no readjustment of the molecular weight distribution during the melt residence in the molding machine, and the fluidity of the low molecular weight components in the molding machine. It is presumed that the generation of aldehydes such as acetaldehyde is further suppressed than in the case of non-inactivated products because the improvement effect remains high.

  Moreover, the generation of aldehydes such as acetaldehyde tends to be accelerated by the polymerization catalyst, and the catalyst is preferably deactivated in order to enhance the effect of the present invention.

In addition, as a deactivation method of a polymerization catalyst, it can carry out also by adding a phosphorus compound.
Examples of the phosphorus compound include phosphoric acid compounds, phosphonic acid compounds, phosphinic acid compounds, phosphorous acid compounds, phosphonous acid compounds, and phosphinic acid compounds.
Specific examples of phosphoric acid compounds include, for example, phosphoric acid, dimethyl phosphate, diethyl phosphate, dipropyl phosphate, dibutyl phosphate, diamyl phosphate, dihexyl phosphate, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, triamyl phosphate Examples thereof include phosphate, trihexyl phosphate, ester of phosphoric acid and alkylene glycol, and the like.

Specific examples of phosphonic acid compounds include, for example, methylphosphonic acid, dimethyl methylphosphonate, diphenyl methylphosphonate, phenylphosphonic acid, dimethyl phenylphosphonate, diphenyl phenylphosphonate, dimethyl phosphophosphonate, diethyl benzylphosphonate, triethylphosphono Examples include acetate, tributylphosphonoacetate, tri (hydroxyethyl) phosphonoacetate, tri (hydroxypropyl) phosphonoacetate, tri (hydroxybutyl) phosphonoacetate and the like.
Specific examples of phosphinic acid compounds include, for example, diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenyl phenylphosphinate, 2-carboxyethyl-methylphosphinic acid, 2 -Carboxyethyl-ethylphosphinic acid, 2-carboxyethyl-propylphosphinic acid, 2-carboxyethyl-phenylphosphinic acid, 2-carboxyethyl-m-toluylphosphinic acid, 2-carboxyethyl-p-toluylphosphinic acid, 2- Carboxyethyl-xylylphosphinic acid, 2-carboxyethyl-benzylphosphinic acid, 2-carboxyethyl-m-ethylbenzylphosphinic acid, 2-carboxymethyl-methylphosphinic acid, 2 Carboxymethyl-ethylphosphinic acid, 2-carboxyethyl-propylphosphinic acid, 2-carboxymethyl-phenylphosphinic acid, 2-carboxymethyl-m-toluylphosphinic acid, 2-carboxymethyl-p-toluylphosphinic acid, 2-carboxy Methyl-xylylphosphinic acid, 2-carboxymethyl-benzylphosphinic acid, 2-carboxymethyl-m-ethylbenzylphosphinic acid, and cyclic anhydrides thereof, or methyl ester, ethyl ester, propyl ester, butyl ester thereof , Ethylene glycol ester, propion glycol ester, ester with butanediol, and the like.

Specific examples of phosphorous compounds include phosphorous acid and dimethyl phosphite, diethyl phosphite, dipropyl phosphite, dibutyl phosphite, diamyl phosphite, dihexyl phosphite, trimethyl phosphite, triethyl phosphite. , Triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4′-biphenylene diphosphite, phosphorous acid and alkylene Examples include esters with glycols.
Specific examples of the phosphonous acid compound include methylphosphonous acid, dimethyl methylphosphonite, diphenyl methylphosphonite, phenylphosphonous acid, phenyldimethylphosphonous acid, and phenyl phenylphosphonite. .

Examples of the method of adding a phosphorus compound include a method of adding at the time of polycondensation, a method of dry blending, a method of immersing chips in a phosphorus compound solution, particularly a phosphoric acid aqueous solution, and a method of adding as a master batch. These phosphorus compounds may be copolymerized with polyester. At this time, a phosphorus compound is added to a polyester of a catalyst (for example, Ge, Sb) whose catalytic activity is not greatly decreased by a phosphorus compound, and blended with a polyester of a catalyst (for example, Ti, Al) whose catalytic activity is decreased by a phosphorus compound. Is also preferable. Thereby, it is possible to easily obtain a polyester having a molecular weight increased to a desired molecular weight while containing a phosphorus compound. In the case of the master batch method, it is preferable to use a polyester master batch in which an amount of 100 to 5000 ppm is copolymerized or blended with a phosphorus compound as a phosphorus atom.
In the case of a method using a phosphorus compound in the form of a chip as a method for deactivating the polycondensation catalyst of the polyester resin, a method for determining the deactivation treatment effect is a method for determining the molded product after molding Is preferably used.

  In addition, by deactivating the catalyst, a transesterification reaction of the polyester occurs at the time of molding, but this transesterification reaction can be suppressed and the conditions at the time of molding can be made wider.

Further, the difference in crystallization temperature at the time of temperature rise of the polyester constituting the polyester resin of the present invention is within 10 ° C, preferably within 8 ° C, more preferably within 7 ° C, and particularly preferably within 5 ° C. desirable. When the difference of the crystallization temperature at the time of the said temperature rise exceeds 10 degreeC, the crystallization speed fluctuation | variation of the obtained molded object becomes large. As a result, for example, the variation in crystallinity of the heat-crystallized hollow molded body plug portion is large, resulting in large dimensional variation of the plug portion, resulting in poor capping properties and leakage of contents. Here, when the polyester resin of the present invention is composed of two or more kinds of polyesters, the difference in crystallization temperature at the time of temperature increase is the value of the polyester having the highest temperature crystallization temperature and the value at the lowest temperature increase. It represents the difference in the values of polyesters having a crystallization temperature.
When the polyester resin of the present invention contains at least two kinds of polyesters as the main components as described above, the type and amount of the polycondensation catalyst described above, melt polycondensation, solid-state polymerization conditions, etc. are appropriately controlled. Can be manufactured by. It can also be obtained by a method of giving an impact to the polyester chip thus obtained, and a method of blending a polyolefin resin, particularly polyethylene, polyamide resin, polyoxymethylene resin, etc. as described below.

  The shape of the polyester chip of the present invention may be any of a cylinder shape, a square shape, a spherical shape or a flat plate shape. The average particle diameter is usually 1.0 to 4 mm, preferably 1.0 to 3.5 mm, and more preferably 1.0 to 3.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.0 to 4 mm and the diameter is about 1.0 to 4 mm. In the case of spherical particles, it is practical that the maximum particle size is 1.1 to 2.0 times the average particle size and the minimum particle size is 0.7 times or more the average particle size. The average weight (W) of the chip is practically in the range of 5 to 50 mg / piece. If the average weight (W) of the chip exceeds 50 mg, it takes a long time to melt in the molding machine, which is a problem that the content of aldehydes such as acetaldehyde is extremely increased. The economical problem that the speed | rate becomes very slow and the economical problem that drying time becomes long at the time of drying of the polyester resin holding a water content of about 2000 ppm or more arise. In addition, in the case of a chip having an average weight of less than 5 mg, fine powder is very easily generated when the chip is handled, and sometimes exceeds 5000 ppm, so that the transparency of the preform is deteriorated as described above. When it is generated or stored in the atmosphere, the moisture absorption rate is fast and becomes 2000 ppm or more in a short time, and it takes a long time to re-dry. In addition, when it is necessary to improve the solid-phase polymerization rate or to reduce the content of aldehydes more effectively, the average weight (W) of the chips is also preferably 1 to 5 mg / piece. .

  The ratio of the average weight (W) of the polyester constituting the polyester resin of the present invention is 1.00 to 1.30, preferably 1.00 to 1.28, more preferably 1.00 to 1.25, Most preferably, it is 1.00-1.20. If the average weight (W) ratio exceeds 1.30, the production of aldehydes at the time of molding increases, and it is not preferable because the equipment cost becomes high, such as using a special nozzle to manufacture chips. Sometimes it becomes difficult to melt and low temperature molding becomes difficult, which is 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 is deteriorated.

Here, when the polyester resin of the present invention is composed of two or more kinds of polyesters, the ratio of the average weight (W) represents the ratio between the value of the polyester with the highest average weight and the value of the polyester with the lowest average weight. .
Further, the difference in crystallinity between the polyester chips constituting the polyester resin 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 molded body and the stretched hollow molded body is improved and acetaldehyde is obtained. The effect of reducing the content is lost, and the above-mentioned blending amount of the polyester tends to occur, which causes the transparency of the polyester molded body and the stretched hollow molded body and the variation of the acetaldehyde content. Here, when the polyester resin of the present invention is composed of two or more kinds of polyesters, the difference in crystallinity is the difference in crystallinity between the maximum polyester and the minimum polyester with respect to crystallinity. .

In the case of a crystallized or solid-phase polymerized polyester resin, the crystallinity of the polyester resin chip should be 40% to 70%, preferably 45 to 65%, more preferably 50 to 63%. Is preferred. If the degree of crystallinity exceeds 70%, the molding temperature must be increased to obtain a molded article having excellent transparency, and the content of aldehydes such as acetaldehyde and free ethylene glycol in the molded article is free. This increases the content of glycol, and deteriorates the flavor retention of the molded product content.
Here, the crystallinity of the chip is calculated from the density of the chip obtained by the following method.

  When the polyester resin of the present invention comprises, for example, the above-mentioned polyester A and polyester B, these can be obtained by uniformly mixing them at a predetermined ratio. For example, the above polyester A and the above polyester B are dry blended with a tumbler, V-type blender, Henschel mixer, static mixer, etc., and the dry blended mixture is 1 with a single screw extruder, twin screw extruder, kneader, etc. For example, a method of melting and mixing more than once. Specifically, it is common that the polyester A and the polyester B are uniformly mixed at a predetermined ratio in the form of chips by the appropriate method, dried, and then subjected to molding.

  Furthermore, the polyester resin of the present invention preferably contains 0.1 ppb to 50000 ppm of at least one resin selected from the group consisting of polyolefin resins and polyacetal resins. The blending ratio of the resin used in the present invention to the polyester resin 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. Is 1.0 ppb to 45 ppb. When the blending amount is less than 0.1 ppb, the crystallization speed becomes very slow and the crystallization of the plug part of the hollow molded body becomes insufficient. Therefore, if the cycle time is shortened, the shrinkage amount of the plug part is specified. Since it does not fall within the range of values, capping defects occur, and the stretched heat-fixed mold that forms a heat-resistant hollow molded body is heavily soiled, and when trying to obtain a transparent hollow molded body, the mold is frequently cleaned. There must be. 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. Further, in the case of a sheet-like material, if it exceeds 50000 ppm, the transparency becomes very poor, the stretchability is also impaired, and normal stretching is impossible, and only a stretched film with large thickness spots and poor transparency can be obtained. .

As polyolefin resin mix | blended with the polyester resin of this invention, polyethylene-type resin, polypropylene-type resin, or alpha-olefin-type resin is mentioned. These resins may be crystalline or amorphous.
Examples of the polyethylene resin blended in the polyester resin of the present invention include ethylene homopolymer, ethylene, propylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1, and hexene. -1, octene-1, decene-1, etc., other α-olefins having about 2-20 carbon atoms, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, styrene, unsaturated Examples thereof include copolymers with vinyl compounds such as epoxy compounds. Specifically, for example, ultra-low / low / medium / high-density polyethylene (branched or linear) ethylene homopolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene- 4-methylpentene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer Examples thereof include ethylene resins such as coalescence and ethylene-ethyl acrylate copolymer.

Moreover, as a polypropylene resin mix | blended with the polyester resin of this invention, the homopolymer of propylene, propylene, ethylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1, Other α-olefins having about 2 to 20 carbon atoms such as hexene-1, octene-1, decene-1, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, styrene, etc. Examples thereof include copolymers with vinyl compounds, and copolymers with dienes such as hexadiene, octadiene, decadiene, dicyclopentadiene, and the like. Specific examples include propylene-based resins such as propylene homopolymer (atactic, isotactic, syndiotactic polypropylene), propylene-ethylene copolymer, propylene-ethylene-butene-1 copolymer.
Moreover, as the α-olefin resin blended in the polyester resin of the present invention, homopolymers of α-olefins having about 2 to 8 carbon atoms such as 4-methylpentene-1, such α-olefins, ethylene , Copolymers with other α-olefins having about 2 to 20 carbon atoms such as propylene, butene-1,3-methylbutene-1, pentene-1, hexene-1, octene-1, and decene-1. It is done. Specifically, for example, butene-1 homopolymers, 4-methylpentene-1 homopolymers, butene-1-ethylene copolymers, butene-1-propylene copolymers, etc. - methylpentene-1 and _C 2 _{-C 18} copolymer of α- olefins, and the like.

Moreover, as a polyacetal resin mix | blended with the polyester resin of this invention, a polyacetal homopolymer and a copolymer are mentioned, for example. The polyacetal homopolymer, the measurement of density measured by a measuring method of ASTM-D792 is ^{1.40~1.42g / cm 3, ASTMD-1238} , 190 ℃, melt flow ratio, measured under a load 2160 g (MFR ) Is preferably in the range of 0.5 to 50 g / 10 min.
Moreover, as a polyacetal copolymer, the density measured by the measuring method of ASTM-D792 is 1.38 to 1.43 g / cm ³ , the melt flow ratio is measured at 190 ° C. and the load is 2160 g by the measuring method of ASTM D-1238. A polyacetal copolymer having a (MFR) in the range of 0.4 to 50 g / 10 min is preferred. Examples of these copolymer components include ethylene oxide and cyclic ethers.

  When the polyolefin resin or the like is blended with the polyester resin of the present invention, the resin such as the polyolefin resin is directly added to the polyester resin or the polyester constituting the polyester resin so that the content is in the above range, and melt-kneaded. In addition to a conventional method such as a method for adding or melting and kneading as a master batch, the resin may be added to the polyester production stage, for example, during melt polycondensation, immediately after melt polycondensation, immediately after precrystallization, In the phase polymerization, immediately after the solid phase polymerization, etc., or in the process from the end of the production stage to the molding stage, it can be added directly as a granular material, or the polyester chip By a method such as bringing a resin into contact with the resin member under flow conditions, or a method of melt-kneading after the contact treatment, etc. It is also possible.

  Here, as a method of bringing the polyester chip into contact with the resin member under flow conditions, it is preferable that the polyester chip is brought into collision contact with the member within the space where the resin member is present. For example, immediately after the melt polycondensation of polyester, immediately after precrystallization, immediately after solid-phase polymerization, etc., at the time of filling and discharging the transport container in the transport stage as a product of polyester chips, etc. When the molding machine is inserted in the chip molding stage, a part of pneumatic transportation piping, gravity transportation piping, silo, magnet catcher magnet part, etc. is made of the resin, or the resin film, sheet, molded body, etc. Or lining the resin, or installing the resin member such as a rod-like or net-like body in the transfer path To include a method of transferring the polyester chips. The contact time of the polyester chip with the member is usually an extremely short time of about 0.01 seconds to several minutes, but a small amount of the resin can be mixed into the polyester resin.

In addition, the polyester resin of the present invention includes polyamide, polyesteramide, low molecular weight amino group-containing compound, hydroxyl group-containing compound, hindered phenyl compound, hindered amine compound, benzotriazole compound, benzophenone compound as aldehyde reducing agents. Compound, polyphenol compound, phosphorus stabilizer, sulfur stabilizer, alkali metal salt can be blended, preferably polyamide, benzophenone compound, polyesteramide, phosphorus stabilizer, low molecular weight amino group-containing compound, A hydroxyl group-containing compound, a benzophenone compound, a hindered phenyl compound, and a hindered amine compound can be blended. Most preferably, it is a polyamide, a polyesteramide, or a low molecular weight amino group-containing compound, and the haze of the obtained polyester molded article is good.
These polyamide compounds, low molecular weight amino group-containing compounds, hydroxyl group-containing compounds and other aldehyde reducing agents may be used alone or in admixture at an appropriate ratio.

The aldehyde reducing agent is, for example, used in an amount of 0.001 to 5 parts by weight, preferably 0.01 to 3 parts by weight, more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the polyester resin of the present invention. it can.
The aldehyde reducing agent can be blended by adding a predetermined amount of aldehyde reducing agent at any reaction stage from the production of a low-polymerization degree oligomer of polyester to the production of polyester polymer. For example, the aldehyde reducing agent may be added to a reactor such as an esterification reactor or a polycondensation reactor in an appropriate form such as a fine granule, powder, or melt, or from the reactor to a reactor in the next step. The aldehyde reducing agent or a mixture of the polyester and the polyester may be introduced in a molten state into a transport pipe for the polyester reactant. Furthermore, if necessary, the obtained chip can be subjected to solid phase polymerization in a high vacuum or in an inert gas atmosphere.

  Moreover, it can also obtain by the method of mixing a polyester resin and an aldehyde reducing agent by a conventionally well-known method, or the method of mixing an aldehyde reducing agent with the mixture of 2 or more types of polyester. For example, polyamide chips and two types of polyester chips with different IVs are dry blended with a tumbler, V-type blender, Henschel mixer, etc., and the dry blended mixture once with a single screw extruder, twin screw extruder, kneader, etc. Examples include those obtained by melting and mixing as described above, and those obtained by subjecting chips from the molten mixture to solid phase polymerization in a high vacuum or inert gas atmosphere as necessary.

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

The fine content of the polyester resin of the present invention is preferably 0.1 to 5000 ppm. The fine content is preferably 0.1 to 3000 ppm, more preferably 0.1 to 1000 ppm, still more preferably 0.1 to 500 ppm, and most preferably 0.1 to 100 ppm. When the blending amount is less than 0.1 ppm, the crystallization rate becomes very slow, and the crystallization of the plug portion of the hollow molded container becomes insufficient, and therefore the shrinkage amount of the plug portion falls within the specified range. It does not fit, and capping becomes impossible. On the other hand, when it exceeds 5000 ppm, the crystallization speed becomes faster than necessary and the fluctuation of the speed becomes large. Therefore, in the case of a sheet-like material, the transparency and the surface state are deteriorated, and when this is stretched, the thickness unevenness is deteriorated. In addition, the degree of crystallinity of the plug part of the hollow molded body becomes excessive and fluctuates, and therefore the shrinkage amount of the plug part does not fall within the specified value range, resulting in poor capping of the plug part and leakage of contents. In addition, the preform for the hollow molded body is whitened, so that normal stretching is impossible. In particular, the fine content of the polyester resin for the hollow molded body is preferably 0.1 to 500 ppm.
Examples of the method for maintaining the fine content of the polyester resin in the above range include a method in which a vibrating sieving machine, a fine removing device, and the like are installed after each polyester manufacturing step, in particular, the solid phase polymerization step.

  Further, the difference between the melting point of the fine contained in the polyester of the present invention and the melting point of the polyester chip is 15 ° C. or less, preferably 10 ° C. or less, more preferably 5 ° C. or less. When the difference includes fines exceeding 15 ° C., the crystals are not completely melted under the usual melt molding conditions and remain as crystal nuclei. For this reason, in the case of a hollow molded body, when the hollow molded body plug portion is heated, the crystallization speed becomes faster, so that the crystallization of the plug portion becomes excessive. In addition, the preform for hollow molding is whitened, so that normal stretching is impossible, thickness unevenness occurs, the crystallization speed is high, and the transparency of the obtained hollow molded body is deteriorated. Fluctuations also become large.

However, when trying to obtain a hollow molding preform or sheet-like material with good transparency and stretchability from a polyester resin containing a fine whose melting point of the fine and the melting point of the chip exceeds 15 ° C., polyester It must be melt molded at a temperature about 40-50 ° C. or higher above the melting point of the chip. However, at such a high temperature, the thermal decomposition of the polyester becomes intense, and a large amount of by-products such as acetaldehyde and formaldehyde are generated, which greatly affects the flavor of the contents of the resulting molded body. It becomes. When the polyester resin of the present invention contains at least one resin selected from the group consisting of the following polyolefin resins, polyamide resins, and polyacetal resins, these resins are generally more thermally stable than the polyester of the present invention. In many cases, it is inferior in properties, and in high-temperature molding as described above, it causes thermal decomposition and generates a large amount of by-products, so it has a greater influence on the flavor of the contents of the obtained molded product etc. It will be.
When the polyester resin of the present invention is PET, a fine or film-like material having a melting point exceeding 265 ° C. becomes a problem.

  As a method of setting the fine melting point in the polyester resin to be used to 265 ° C. or less, for example, a method using the fine removal apparatus as described above, a plug transport method or a bucket type conveyor transport method is adopted as a polyester transport method in the manufacturing process. The method and extraction of the chip from the storage tank include a method using a screw type feeder, and the like can be used in combination.

  The melting point of the fine is measured by the following method using a differential scanning calorimeter (DSC), and the melting peak temperature representing the melting point of the fine is one or more melting peaks. In the present invention, when there is one melting peak, the peak temperature is indicated, and when there are a plurality of melting peaks, the highest temperature among the plurality of melting peaks is indicated. The melting peak temperature is referred to as “the highest peak temperature of the fine melting peak temperature”, and is referred to as “fine melting point” in the examples.

  The polyester resin of the present invention can be used to form a sheet material, a biaxially stretched film, a hollow molded body, a tray or other packaging material by using a commonly used melt molding method, or by another method using a melt extrusion method. A coating can be formed on the material. Moreover, the polyester resin of this invention can be used also as 1 component layers, such as a multilayer molded object and a multilayer film. It can also be used as a base material on which an oxygen barrier film such as carbon or silica is deposited.

  The method for producing a polyester molded body from the polyester resin of the present invention will be briefly described below by taking a polyester resin containing, as a main component, a polyester having ethylene terephthalate as a main repeating unit as an example, but is not limited thereto. Absent. The polyester resin of the present invention is a film using a generally used melt 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. Sheets, containers, and other molded articles that become other packaging materials can be molded. As conditions for the molding production, the molten resin temperature is 260 to 295 ° C., preferably 262 to 290 ° C., more preferably 265 to 265 ° C. by heating a barrel, a die, a hot runner, etc. of an injection molding machine or an extrusion molding machine. It is important to set the temperature within the 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, and in the case of injection molding, the injection molding machine The cycle time, the metering stroke (screw back amount) and the like are arbitrarily set, and the time is set in the range of 10 to 500 seconds, preferably 20 to 300 seconds, and more preferably 30 to 200 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 (8).
t = W × S / P
Formula (8) where W: weight of molten resin in a cylinder and hot runner of an injection molding machine (g)
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 295 ° C. and setting the melt residence time in the range of 10 to 500 seconds, at least two kinds of mainly ethylene terephthalate are used as the main repeating unit. From a polyester resin containing a polyester 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 There can be obtained a molded body such as a preform for a hollow molded body that is free from the occurrence of a partial whitened product or a bowl-like product and has no problem in the shape of the plug portion 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 an injection molding machine or the like is large and molding becomes difficult, the obtained preform becomes extremely poor in transparency, and the thickness of the sheet-like material varies. growing. Moreover, when the temperature exceeds 295 ° C., the thermal decomposition becomes severe and the content of aldehyde such as acetaldehyde increases, which is a problem. When the melt residence time is less than 10 seconds, the transparency of the preform is deteriorated due to insufficient melting, and when it exceeds 500 seconds, the transparency of the preform is very good, but aldehydes such as acetaldehyde. The content of is increased, the molding cycle becomes longer, and the productivity of the preform is lowered.

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

By molding the polyester resin of the present invention under the molding conditions described above, it is possible to obtain the polyester molded body or the stretched polyester hollow molded body of the present invention.
Here, the polyester molded body refers to a polyester molded body such as a sheet-like material or a cup-like material used as it is and the following polyester preform. A polyester preform is a non-stretched sheet obtained by melt extrusion molding polyester, a preform obtained by compression molding a melt mass obtained by melt extrusion molding, or obtained by injection molding. It is a preform that can be used. Further, it is a molded body that is melt-extruded and extruded into a pipe shape (so-called direct blow molded body), and then a cylindrical molded body that is further molded into a container, a cup-shaped molded body that is obtained by injection molding, Also included are molded products that are commercialized as containers by laminating paper and non-woven fabrics.

  Moreover, it is possible to improve mechanical strength by extending | stretching the sheet-like material which consists of a polyester resin of this invention at least to a uniaxial direction. The stretched film made of the polyester resin of the present invention is a sheet-like product obtained by injection molding or extrusion molding, and is optionally stretched among uniaxial stretching, sequential biaxial stretching, and simultaneous biaxial stretching that are generally used for PET stretching. Molded using the method. Further, it can be formed into a cup shape or a tray shape by pressure forming or vacuum forming.

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

  In producing the stretched hollow molded body, the blow molded from the polyester resin of the present invention is stretched and 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 300 ° 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.

Moreover, the polyester resin of this invention can be used also for manufacture of the preform used for manufacture of the heat resistant bottle by the two-stage blow molding method provided with a primary blow molding process and a secondary blow molding process.
In the case of the two-stage blow molding method of PET, a preform obtained by crystallizing the plug portion as described above in the primary blow molding step is 1.0 to 1.0 to the final product volume at the same stretching temperature as described above. The biaxially stretched blow molding is performed about twice, and then the obtained primary molded body is heated at about 100 to 250 ° C. and then subjected to secondary blowing in a mold of about 80 to 200 ° C. in the secondary blow molding step.

  The polyester resin 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 melted mass cut after melt extrusion is stretch blow molded. it can.

Another application of the polyester resin of the present invention is a film laminated on one or both sides of a laminated metal plate. Examples of the metal plate used include tinplate, tin-free steel, and aluminum.
As a laminating method, a conventionally known method can be applied, and it is not particularly limited. However, 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, they may be laminated 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 resin 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, stabilizers as necessary In addition, various additives such as an antistatic agent, a bluing agent, a dye and a pigment, and a polyamide resin from metaxylylenediamine and adipic acid may be added to improve oxygen permeability.

  In addition, when the polyester resin of the present invention is used for film applications, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate is used in the polyester in order to improve handling properties such as slipperiness, rollability, and blocking resistance. , Inorganic particles such as barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, organic salt particles such as terephthalate such as calcium oxalate, calcium, barium, zinc, manganese, magnesium, divinylbenzene, styrene, acrylic acid, methacrylic Inactive particles such as crosslinked polymer particles such as homopolymers or copolymers of vinyl monomers of acid, acrylic acid or methacrylic acid can be contained.

  Further, the content of aldehydes in the polyester molded article or the stretched polyester article of the present invention is 50 ppm or less, preferably 30 ppm or less, more preferably 20 ppm or less.

  In addition, when the polyester stretch molded product of the present invention is made of a polyester resin having ethylene terephthalate as a main repeating unit, and this is used as a material for a container for low flavor beverages such as mineral water, The acetaldehyde content of the stretched polyester molded article is 15 ppm or less, preferably 12 ppm or less, more preferably 10 ppm or less, and most preferably 7 ppm or less.

The free ethylene glycol content of the stretched hollow polyester body of the present invention is 50 ppm or less, preferably 40 ppm or less, more preferably 30 ppm or less, most preferably 20 ppm or less, and the free diethylene glycol content is 20 ppm or less, preferably 15 ppm or less, more preferably 13 ppm or less, and most preferably 10 ppm or less.
As a means for maintaining the free ethylene glycol content of the stretched hollow polyester molded body at 50 ppm or less and the free diethylene glycol content at 20 ppm or less, as well as using the polyester resin having the above-mentioned characteristics, There are methods such that the moisture content of the polyester resin is 100 ppm or less, preferably 50 ppm or less, drying is carried out under reduced pressure or in an inert air stream, and molding is performed under the melt molding conditions of the present invention. One or more of these may be combined appropriately.

  When the polyester molded body of the present invention is made of a polyester resin having ethylene terephthalate as the main repeating unit, the crystallization temperature (Tc1) at the time of temperature rise is 140 to 175 ° C., and the crystal at the time of temperature fall. The conversion temperature (Tc2) is preferably 160 to 190 ° C. When Tc1 is less than 140 ° C., whitening occurs during preheating before molding, resulting in poor stretchability and poor transparency. When Tc1 exceeds 175 ° C., the crystallization process of the plug part of the hollow molded body for heat-resistant applications becomes insufficient, and the plug part is deformed when hot filling a hot beverage, causing leakage after capping. It becomes.

  When the polyester molded body of the present invention is made of a polyester resin having ethylene terephthalate as the main repeating unit, the polyester molded body or the stretched hollow molded body is melted at a temperature of 290 ° C. for 60 minutes. The increase in the amount of cyclic trimer at the time is preferably 0.40% by weight or less. For this purpose, the polyester used is obtained by the polymerization of the polyester obtained after the melt polycondensation or the solid phase polymerization as described above. It can be produced by deactivating the condensation catalyst. The increase amount of the cyclic trimer when melted at a temperature of 290 ° C. for 60 minutes is preferably 0.3% by weight or less, more preferably 0.1% by weight or less. If the increase exceeds 0.4% by weight, the cyclic trimer, linear monomer, and linear oligomer increase when the resin is melted during molding, and the adhesion of the oligomer to the vent hole of the molding die increases rapidly and continues. Production becomes difficult, and flavor retention of the obtained stretched polyester hollow molded article is deteriorated.

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.
The composition of the polyester and the properties (1) to (4) are measured after the chips are frozen and ground and mixed thoroughly.

(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 resin 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, made up to a constant volume with 10 ml of dimethylformamide, and the cyclic trimer was quantified by high performance liquid chromatography.

(4) Increasing amount of cyclic trimer at the time of melting polyester (△ CT amount)
The polyester resin is frozen and pulverized, and then 3 g of the dried polyester sample is put into a glass test tube and immersed in an oil bath at 290 ° C. for 60 minutes in a nitrogen atmosphere and melted. The amount of increase in cyclic trimer at the time of melting is determined by the following equation.
The cyclic trimer content before melting was the weighted average value of the cyclic trimer content of the polyester constituting the polyester resin.
Increase in cyclic trimer during melting (wt%) =
Cyclic trimer content after melting (wt%)-cyclic trimer content before melting (wt%)
In addition, when calculating | requiring the cyclic | annular trimer increase amount at the time of the fusion | melting of a molded object, it is a size of about 1-3 mm from the mouth of the 3 mm thickness plate obtained by the postscript (17) or the molded object shape | molded by (18). Cut the strips into samples. In this example, a strip from a 3 mm thick plate (B portion in FIG. 1) was used as a sample.

(5) Acetaldehyde content of polyester (hereinafter referred to as “AA content”) and AA increase before and after molding (hereinafter referred to as “ΔAA amount”)
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. Moreover, the variation value ((DELTA) AA amount) of the acetaldehyde content of a hollow molded object was measured about ten, and the difference of the maximum value and the minimum value was calculated | required.

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

(7) Average weight (W) of polyester chip and ratio of average weight (W _A / W _B )
After removing fines with ion-exchanged water, the weight of 100 dried polyester chips was measured, and the average value was defined as the average weight (W). When the polyester resin is a mixture of two kinds of polyesters, the ratio of the average weight of the two kinds of polyester chips (W _A / W _B ) is the average weight of the polyester chips having a large average weight among the two kinds. is _a, the average weight of the average weight of small polyester chips as _{W B,} was calculated _W a / W _B. When the two types of polyester chips have the same average weight, W _A / W _B is 1.00. Moreover, when it consists of 2 or more types of polyester, it calculates as mentioned above for 2 types of polyester with many mixing ratios. In this case, the selection of 100 chips was performed by excluding abnormally sized chips. That is, 100 chips are selected at random and the average weight (W) is calculated. Then, chips with a weight less than 0.5 W and chips with a weight exceeding 2 W are excluded, and the number of excluded chips is selected again at random. Then, 100 average values were recalculated. This was performed until all 100 chips were within 0.5 W to 2 W.

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

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

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

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

(12) Crystallization temperature (Tc1) when the molded body is heated and crystallization temperature (Tc2) when the temperature is lowered
Measured with a differential thermal analyzer (DSC), RDC-220, manufactured by Seiko Electronics Industry Co., Ltd. Using 10 mg of a sample from the center of a 2 mm thick plate of the molded plate (17) below. The temperature was raised at a rate of temperature rise of 20 ° C./minute and held at 290 ° C. for 3 minutes, then the temperature was lowered from 290 ° C. to 240 ° C. at 10 ° C./minute, and further from 240 ° C. to 130 ° C. at 7 ° C./minute. The temperature dropped. The peak temperature of the crystallization peak observed at the time of temperature rise is defined as the crystallization temperature (Tc1) at the time of temperature increase, and the peak temperature of the crystallization peak observed at the time of temperature decrease is defined as the crystallization temperature (Tc2).

(13) Haze (degree of haze) and haze spots A sample was cut from the molded product (thickness 5 mm) of (17) below and measured with a Nippon Denshoku Co., Ltd. haze meter, model NDH2000. Moreover, the haze of the molded board (thickness 5 mm) shape | molded continuously 50 times was measured, and the haze spot was calculated | required by the following.
Haze spots = maximum value of haze / minimum value of haze Further, the haze of the stretched hollow molded body was measured by using a haze meter, model NDH2000, manufactured by Nippon Denshoku Co., Ltd., by cutting a sample from the bottle body of the following (18).

(14) Thermal stability parameter (TS)
After putting 1 g of PET resin chip (before melting test; [IV] _i ) into a glass test tube with an inner diameter of about 14 mm and vacuum-drying at 130 ° C. for 12 hours, set it on the vacuum line and repeat decompression and nitrogen filling 5 times or more Sealed with 100 mmHg nitrogen, immersed in a salt bath at 300 ° C. and maintained in a molten state for 2 hours, a sample was taken out, freeze crushed and vacuum dried, and IV (after melting test; IV) _{f 2} ) And measured using the following formula. The freeze pulverization was performed according to the method described in (15) below.
The formula was quoted from a previous report (Ueyama et al .: Journal of Japan Rubber Association Vol. 63, No. 8, 497, 1990).
TS = 0.245 {[IV] _f2 ^-1.47- [IV] _i ^-1.47 }.

(15) Thermal oxidation stability parameter (TOS)
PET resin chip (before heat test; [IV] _i ) was frozen and pulverized to a powder of 20 mesh or less and vacuum-dried at 130 ° C. for 12 hours, and 300 mg was put into a glass test tube having an inner diameter of about 8 mm and a length of about 140 mm. After vacuum drying at 70 ° C. for 12 hours, a drying tube containing silica gel is attached to the top of the test tube, and under a dry air, the IV is measured after being immersed in a 230 ° C. salt bath and heated for 15 minutes. It calculated | required using the following formula same as TS. However, [IV] _i
And [IV] _f1 refer to IV (deciliter / gram) before and after the heating test, respectively. The freeze pulverization was carried out using a freezer mill (6750 model manufactured by US Specs). After putting about 2 g of resin chip and a dedicated impactor in a dedicated cell, the cell is set in the apparatus, filled with liquid nitrogen and held for about 10 minutes, and then RATE10 (the impactor is about 20 per second). Pulverized for 5 minutes.
TOS = 0.245 {[IV] _f1 ^-1.47- [IV] _i ^-1.47 }.

(16) Hydrolysis resistance parameter (HS)
A PET resin chip (before hydrolysis test; [IV] _i ) was frozen and crushed into a powder of 20 mesh or less in the same manner as in (15) above, and dried in a vacuum at 130 ° C. for 12 hours. The hydrolysis test was performed using a mini color apparatus (TypeMC12.ELB manufactured by Tecsum Giken Co., Ltd.). 1 g of the above powder was put together with 100 ml of pure water into a special stainless beaker, and a special stirring blade was further added to make a closed system, which was set in a mini-color device, heated to 130 ° C. and stirred for 6 hours under pressurized conditions. The PET after the test was filtered with a glass filter and vacuum-dried, and then IV was measured ([IV] _f3 ), and the hydrolysis resistance parameter (HS) was determined by the following equation.
HS = 0.245 {[IV] _f3 ^-1.47- [IV] _i ^-1.47 }

(17) Molding of stepped molded plate
The polyester dried under reduced pressure at 140 ° C. for about 16 hours using a vacuum dryer has a gate part (G) as shown in FIGS. 1 and 2 by an injection molding machine M-150C-DM type injection molding machine manufactured by Meiki Seisakusho. 2 mm to 11 mm (A part thickness = 2 mm, B part thickness = 3 mm, C part thickness = 4 mm, D part thickness = 5 mm, E part thickness = 10 mm, F part thickness = 11 mm) The stepped molding plate was injection molded.
Polyester previously dried under reduced pressure using a vacuum dryer DP61 manufactured by Yamato Scientific 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 Including 280 ° C. or 290 ° C. The injection conditions are 20% for injection speed and holding pressure, and the injection pressure and holding pressure are adjusted so that the weight of the molded product is 146 ± 0.2g. In this case, the holding pressure is 0.5MPa lower than the injection pressure. It was adjusted.
The upper limit of the injection time and pressure holding time is set to 10 seconds and 7 seconds, respectively, and the cooling time is set to 50 seconds. The total cycle time including the time for taking out the molded product is about 75 seconds.
The mold is always controlled by introducing cooling water having a water temperature of 10 ° C., but the mold surface temperature at the time of molding stability is around 22 ° C.
The molding temperature refers to the set temperature of the barrel including the nozzle.
The stepped molding plates used for measurement of various polyester molding plates Tc1 and Tc2 used in Examples and Comparative Examples are molding plates molded at a 290 ° C. molding temperature.
Moreover, the molded board of 280 degreeC shaping | molding temperature was used for the measurement of the molded board haze (%) and molded board haze spot (%) of the polyester resin in an Example and a comparative example.
The test plate for evaluating the characteristics of the molded product was arbitrarily selected from the 11th to 18th shots of the stable molded product after the molding material was introduced and the resin was replaced.
A 2 mm thick plate (part A in FIG. 1) measures the crystallization temperature (Tc1) at the time of temperature rise and a crystallization temperature (Tc2) at the time of the temperature fall, and the 3 mm thickness plate (part B in FIG. 1) is a cyclic trimer. An increase amount (ΔCT amount) measurement, a 5 mm-thick plate (D portion in FIG. 1) is used for haze measurement.

(18) Molding of hollow molded body 1) Molding of preform In order to prevent moisture absorption of the chip during molding using a polyester chip that has been dried in advance using a vacuum dryer DP63 model manufactured by Yamato Scientific Co., Ltd., a molding material hopper The inside was purged with a dry inert gas (nitrogen gas).
The plasticizing conditions of the M-150C-DM injection molding machine manufactured by Meiki Seisakusho Co., Ltd. are as follows: feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, weighing position 50 mm, cylinder temperature from directly below the hopper In order, the temperature was set to 45 ° C., 250 ° C., and thereafter the molten resin temperature including the nozzle was 280 ° C. The injection conditions were such that the injection speed and holding pressure were 10%, and the injection pressure and holding pressure were adjusted so that the weight of the molded product was 58.6 ± 0.2 g. Adjusted to 5 MPa lower. The cooling time is set to 20 seconds, and the total cycle time including the molded product take-out time is approximately 42 seconds. The preform has an outer diameter of 29.4 mm, a length of 145.5 mm, and a wall thickness of about 3.7 mm.
The mold is always controlled by introducing cooling water having a water temperature of 18 ° C., but the mold surface temperature at the time of molding stability is around 29 ° C. The preform for property evaluation was arbitrarily selected from stable molded products 20 to 50 shots after the start of molding after introducing the molding material and replacing the resin.
2) Molding of stretched hollow molded body (bottle) The plug portion of the preform was heated and crystallized with a home-made plug portion crystallization apparatus. Next, this preform was biaxially stretched and blown at a magnification of about 2.5 times in the longitudinal direction and about 3.8 times in the circumferential direction on a LB-01E molding machine manufactured by CORPOPLAST, and subsequently set at about 145 ° C. It was heat-set in the mold for 7 seconds to mold a 1500 cc container (trunk thickness 0.45 mm). The stretching temperature was controlled at 100 ° C. and arbitrarily selected from the stable molded products on the 10th to 30th shots from the start of molding. A sample was taken from the mouth of the bottle and used for measurement of acetaldehyde content (AA content), cyclic trimer content (CT content), free EG content, and free DEG content.

(19) Appearance of preform for hollow molded body The preform molded in (18) was observed from the direction of the plug and evaluated as follows.
◎: Almost colorless and transparent △: Transparent but strong yellow color ×: Opaque ××: Opaque and yellow

(20) Shape and size of the plug portion of the preform for hollow molded body The shape and size of the plug portion crystallized in (18) above was 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.

(21) Appearance of stretched hollow molded body 20 hollow molded bodies from the 10th molding start of the above (18) were visually observed and evaluated as follows.
◎: Transparent and no appearance problems △: Transparent but strong yellowish color ×: Slightly whitened flow pattern or whitened product on hollow molded body XX: White molded flow pattern or whitened product on hollow molded body

(22) Measuring the strength of the bottle body The bottle body formed by the above method was cut into large pieces with a cutter and punched with a super dumbbell cutter model SDMK-1000D manufactured by Dumbbell Co., Ltd. (according to JISK-7162-5A). The strength was measured using a tensile tester SS-207D-U (manufactured by Toyo Baldwin Co., Ltd.).

(23) Free glycol content of polyester (hereinafter, free ethylene glycol content is referred to as “free EG content”, and free diethylene glycol content is referred to as “free DEG content”)
About 1.000 g of a sample is precisely weighed and dissolved in 8 mL of a hexafluoroisopropanol / chloroform (2/3) mixed solvent in an Erlenmeyer flask, and then 3 mL of distilled water is added to homogenize the contents. The mixed solvent is distilled off, and the residual aqueous phase is filtered using a glass fiber filter. The filtrate was made up to 10 mL with water and quantified by gas chromatography.

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

(Polyester 1)
A slurry of high-purity terephthalic acid and ethyl glycol was continuously supplied to the first esterification reactor containing the reactants in advance, and averaged at about 250 ° C. and 0.5 kg / cm ² G under stirring. The reaction was carried out for a residence time of about 3 hours. This reaction product was sent to the second esterification reactor, and the reaction was carried out with stirring at about 260 ° C. and 0.05 kg / cm ² G to a predetermined reactivity. Ethylene glycol solution of basic aluminum acetate, Irganox 1222 (manufactured by Ciba Specialty Chemicals Co., Ltd.) and ethylene glycol solution pre-heated with ethylene glycol were mixed in advance with 0.01 mol% as Irganox 1222 to the acid component. The second esterification reactor was continuously fed. The esterification reaction product was continuously fed to the first polycondensation reactor, and stirred for about 1 hour at about 265 ° C. and 25 torr, and then stirred for about 2 hours in the second polycondensation reactor at about 265 ° C. and 3 torr. The mixture was further subjected to polycondensation at about 275 ° C. and 0.5 to 1 torr for about 2 hours with stirring in the final polycondensation reactor for about 1 hour. The cooling water at the time of chip formation is ion-exchanged water having a sodium content of 0.1 ppm, a calcium content of about 0.1 ppm, a magnesium content of about 0.06 ppm, and a silicon content of about 0.7 ppm. Using.
The IV of the obtained melt polycondensed PET was 0.55 deciliter / gram.
This melt polycondensed PET was chipped and transported to a storage tank. Fines were then removed by a vibration sieving step and an airflow classification step, and then transported to a continuous solid-state polymerization apparatus. Crystallization was performed at about 155 ° C. in a nitrogen atmosphere, and after preheating to about 200 ° C. in a nitrogen atmosphere, the mixture was sent to a continuous solid-phase polymerization reactor and subjected to solid phase polymerization at about 208 ° C. in a nitrogen atmosphere. A PET having an IV of 0.70 deciliter / gram, an AA content of 3.5 ppm, and a density of 1.400 g / cm ³ was obtained. The sodium content was 0.03 ppm, the calcium content was 0.05 ppm, and the silicon content was 0.6 ppm.
The properties of the obtained PET are shown in Table-1.

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

(Polyester 3 (Pes3))
A prepolymer was obtained by melt polycondensation in the same manner as polyester 1 except that the amount of polycondensation catalyst added was changed.
The resulting prepolymer was finely removed and then charged into a rotary vacuum solid-phase polymerization apparatus, and crystallized at 70 to 160 ° C. under reduced pressure while rotating, followed by solid-phase polymerization at 210 ° C. After solid-phase polymerization, fines were removed in the sieving step. The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, and silicon content were similar to those of polyester 1.

(Polyester 4 (Pes4), 5 (Pes5))
Polyesters 4 and 5 were obtained by reacting in the same manner as for polyester 1 except that an ethylene glycol solution of titanium tetrabutoxide and an ethylene glycol solution of magnesium acetate tetrahydrate were used as the polycondensation catalyst.
The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, and silicon content were similar to those of polyester 1.

(Polyester 6 (Pes6))
Using ethylene glycol solution of antimony trioxide as a polycondensation catalyst, sodium content is about 9.0ppm, calcium content is about 10.1ppm, magnesium content is about 5.0ppm, silicon content as cooling water when chipping A melt polycondensation prepolymer (IV = 0.48 deciliter / gram) was obtained in the same manner as the prepolymer of polyester 1 except that the amount of water used was 10.5 ppm. The obtained prepolymer was put into a rotary reduced pressure solid phase polymerization apparatus without fine removal, and crystallized at 70 to 160 ° C. under reduced pressure while rotating, followed by solid phase polymerization at 210 ° C. After the solid phase polymerization, fines were not removed in the sieving step. The properties of the obtained PET are shown in Table 1.
The sodium content was 4.0 ppm, the calcium content was 5.1 ppm, and the silicon content was 5.4 ppm.

(Polyester 7 (Pes7))
As a polycondensation catalyst, an ethylene glycol solution of antimony trioxide and an ethylene glycol solution of cobalt acetate were used and reacted in the same manner as for polyester 1 except that the solid phase polymerization time was extended to obtain polyester 7.
The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, and silicon content were similar to those of polyester 1.

(Polyester 8 (Pes8))
A prepolymer was obtained by melt polycondensation in the same manner as for polyester 1 except that an ethylene glycol solution of antimony trioxide was used as the polycondensation catalyst and water having the same quality as that of polyester 6 was used as the chip cooling water. Next, polyester 8 was obtained by reacting in the same manner as polyester 7 except that the solid phase polymerization time was changed. The properties of the obtained PET are shown in Table-1. Sodium content, calcium content, and silicon content were similar to those of polyester 1.

Note: Molded plate Tc1, Tc2 = Value of molded plate molded at 290 ° C

(Example 1)
The polyester resin obtained by blending the above synthesized polyester 1 and polyester 2 pellets in a ratio of 7: 3 is injection molded by the method (18) under the conditions of a molten resin temperature of 280 ° C. and a melt residence time of 110 seconds. The preform and stretch-molded bottle obtained in this manner were evaluated. The results are shown in Table 2.

(Example 2)
As a phosphoric acid aqueous solution, phosphoric acid is uniformly attached to the chip surface of a 7: 3 mixture of polyester 1 and polyester 2 so that the molar ratio (P / Al) of P residual content to Al residual content is about 1.7. Evaluation was similarly performed about the made polyester resin.
The results are shown in Table 2. All the evaluated characteristics were as good as in Example 1.

(Comparative Example 1)
As shown in Table 2, the polyester composition of Comparative Example 1 was evaluated in the same manner as in Example 1.
Obviously, the haze value and haze spots of the molded plate are large compared to the examples, and the shape and dimensions after crystallization of the preformed body plug portion are insufficiently crystallized and poorly shaped, and the appearance is also opaque. The AA content and appearance of the stretched molded product were not so good. The results are shown in Table 2.

(Comparative Example 2)
As shown in Table 2, the polyester resin of Comparative Example 2 was evaluated.
Obviously, the appearance of the preform was opaque and yellow when compared with the examples, and the AA content of the stretched molded product was problematic. The results are shown in Table 2.

(Comparative Example 3)
As shown in Table 2, the polyester resin of Comparative Example 3 was evaluated.
Obviously, the haze value and haze spots of the molded plate are high compared to the examples, the shape and dimensions after crystallization of the preformed plug part are insufficiently crystallized, the shape is poor, the appearance is opaque, and the hollow The AA content of the molded body was large and the appearance was very bad. The results are shown in Table 2.

(Comparative Example 4)
As shown in Table 2, the polyester 8 of Comparative Example 4 was evaluated.
Obviously, the haze value and haze spots of the molded plate are high compared to the examples, and the shape and dimensions after crystallization of the preformed body plug part are poorly shaped due to excessive crystallization, and the appearance of the hollow molded body It was bad too. The results are shown in Table 2.

  The present invention provides a polyester resin that provides a molded product that has a small amount of aldehydes during molding due to improved flow characteristics and that has excellent mechanical properties such as pressure resistance when formed into a molded product. . In particular, an inexpensive polyester resin comprising a polyester polymerized using at least one selected from the group consisting of aluminum and a compound thereof as a polyester polymerization catalyst is provided. In addition, since the polyester resin of the present invention has improved flow characteristics, there is little distortion at the time of molding, and a molded body excellent in heat-resistant dimensional stability, particularly a hollow molded product, can be efficiently produced by high-speed molding, and Provided is a polyester resin having a very good pressure resistance and heat-resistant dimensional stability, and excellent in long-time continuous moldability with less fouling of a mold, a molded product comprising the same, and a method for producing the molded product.

Claims (13)

  A polyester resin comprising as a main component at least two polyesters having substantially the same composition, wherein the polyester has a difference in intrinsic viscosity of 0.05 to 0.30 deciliter / gram, and the polyester is aluminum. And a polyester resin polymerized using at least one selected from the group consisting of the compounds thereof as a catalyst.   A polyester resin comprising as a main component at least two polyesters having substantially the same composition, wherein the polyester has a difference in intrinsic viscosity of 0.05 to 0.30 deciliter / gram, and the polyester is aluminum. And a polyester resin polymerized using a catalyst containing one kind selected from the group consisting of the compounds and a phenol compound and / or a phosphorus compound.   The polyester resin according to claim 1, wherein the cyclic ester oligomer content is 70% or less of the cyclic ester oligomer content of the melt polycondensation polyester. The polyester resin contains, as main components, the following polyester A and polyester B having ethylene terephthalate as a main repeating unit, and the crystallization temperature when the polyester A is cooled and the crystallization temperature when the polyester B is lowered The polyester resin according to claim 1, wherein the difference is within 20 ° C.
Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.80 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at the time of temperature increase measured by DSC is 140 to 180 ° C., and the crystallization temperature at the time of temperature decrease is Polyester that is 160-200 ° C.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.95 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at the time of temperature increase measured by DSC is 140 to 180 ° C., and the crystallization temperature at the time of temperature decrease is Polyester that is 160-200 ° C. The polyester resin according to claim 4, wherein the thermal stability parameter (TS) of the polyester A and the polyester B satisfies the following formula (1).
TS <0.30 (1) Formula (TS is a melting test (1 g of a polyester resin chip is placed in a glass test tube and vacuum dried at 130 ° C. for 12 hours, and then melted at 300 ° C. for 2 hours in a non-circulating nitrogen atmosphere) It is a value obtained by measuring the intrinsic viscosity before and after) and using the following formula.
TS = 0.245 {[IV] _f2 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f2 indicate intrinsic viscosities (unit: deciliter / gram) before and after the melting test, respectively. ) The polyester resin according to claim 4 or 5, wherein the thermal oxidation stability parameter (TOS) of the polyester A and the polyester B satisfies the following formula (2).
TOS <0.20 (2) (TOS is a heat test (polyester resin chips are frozen and pulverized to a powder of 20 mesh or less, vacuum-dried at 130 ° C. for 12 hours, 0.3 g is put in a glass test tube, This is a value obtained by measuring the intrinsic viscosity before and after vacuum drying at 70 ° C. for 12 hours and then heating at 230 ° C. for 15 minutes in air dried with silica gel and using the following formula.
TOS = 0.245 {[IV] _f1 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f1 indicate intrinsic viscosities (unit: deciliter / gram) before and after the heating test, respectively. ) The polyester resin according to any one of claims 4 to 6, wherein the hydrolysis resistance parameter (HS) of the polyester A and the polyester B satisfies the following formula (3).
HS <0.10 (3) Formula (HS is a hydrolysis test (freeze-pulverized polyester resin chips are made into a powder of 20 mesh or less, vacuum-dried at 130 ° C. for 12 hours) 1 g of pure water is put into a beaker with 100 ml of pure water. It is a value obtained by measuring the intrinsic viscosity before and after stirring for 6 hours under the condition of heating and pressurizing at 130 ° C. in a closed system and using the following formula.
HS = 0.245 {[IV] _f3 ^-1.47- [IV] _i ^-1.47 }
[IV] _i and [IV] _f3 indicate intrinsic viscosities (unit: deciliter / gram) before and after the hydrolysis test, respectively. )   The polyester resin according to claim 1, wherein an increase in cyclic ester oligomer when melted at a temperature of 290 ° C. for 60 minutes is 0.40 wt% or less.   The polyester resin according to any one of claims 1 to 8, wherein 0.1 ppb to 1000 ppm of at least one resin selected from the group consisting of a polyolefin resin, a polyamide resin, and a polyacetal resin is blended.   A polyester molded article obtained by molding the polyester resin according to claim 1.   The polyester molded body according to claim 10 is a hollow molded body preform, a sheet-shaped preform, or a stretched film or stretch blown hollow molded body obtained by stretching these preforms in at least one direction. A polyester molded body characterized by being selected.   The polyester molded body according to claim 10, wherein the polyester molded body is a coating obtained by melt-extruding a polyester resin on a base material. The polyester resin according to any one of claims 1 to 9 is kneaded and molded under the conditions that the molten resin temperature in the molding machine is 260 to 295 ° C and the melt residence time in the molding machine is 10 to 500 seconds. A method for producing a polyester molded body.