TW201835184A - Polyester, method for producing the same and shaped article of the same - Google Patents

Abstract

Provided is a polyester which contains at least 50 mol% of a terephthalic acid unit with respect to the sum total of dicarboxylic acid units, and which contains at least 50 mol% of an ethylene glycol unit with respect to the sum total of diol units, and which is obtained by polycondensation of a dicarboxylic acid and a diol in the presence of: a cobalt compound (M); at least one type of phosphorus compound (P) selected from the group consisting of phosphoric acid, phosphorous acid, organo-phosphonic acid, and esters thereof; and a poly-carboxylic acid (X) having an [alpha],[beta]-dicarboxylic acid unit, wherein the cobalt compound (M) is added in an amount of 0.0005-0.05 parts by mass in terms of cobalt element with respect to 100 parts by mass of the sum total of dicarboxylic acids, the molar ratio (P/M) of the phosphorus atoms in the phosphorus compound (P) with respect to the cobalt atoms in the cobalt compound (M) is 0.01-10, and the molar ratio (X/M) of the poly-carboxylic acid (X) with respect to the cobalt atoms in the cobalt compound (M) is 0.01-10. Such polyester exhibits a good color tone, and molded articles obtained using said polyester are highly transparent and exhibit excellent impact resistance.

Description

Polyester, method for producing the same, and formed article formed therefrom

The present invention relates to a polyester having high transparency, good color tone, and excellent impact resistance, a method for producing the same, and a molded article formed therefrom.

Polyesters such as polyethylene terephthalate have excellent transparency, mechanical properties, gas barrier properties, and odor barrier properties. In addition, when the polyester is made into a molded product, there is no concern about residual monomers or harmful additives, and it has excellent hygiene and safety. Therefore, polyester systems can activate these characteristics and have been widely used in recent years as hollow containers for filling vinyl chloride, beverages, seasonings, oils, cosmetics, lotions, etc. that can be used in the past.

As a molding method for producing a hollow molded article made of polyester, it is known to extrude a melt-plasticized resin as a cylindrical parison through a die hole, and while the parison is in a softened state, An extrusion blow molding method in which a mold is sandwiched and a fluid such as air is blown into the inside to perform molding. Compared with the injection blow molding method, this method has simple steps, and because it does not require model making and high-level molding technology, the cost of equipment costs or model making costs can be reduced, which is suitable for most types and small amounts of production. In addition, it is also possible to manufacture molded articles with complex shapes such as thin materials, thick materials, large materials, and handles.

However, in cosmetics, oil containers, etc., in addition to having excellent properties such as chemical resistance and gas barrier properties, in order to prevent breakage caused by shocks such as dropping, excellent mechanical properties are also required. In addition, in cosmetic containers and the like, the texture or appearance of glass is required. However, polyester is dyed yellow during molding. Therefore, in order to improve the color tone, it is often the case that a bluing agent is used. In particular, a strong blue cobalt compound or the like is used.

However, when a cobalt compound is added during polymerization, the polymer aggregates in the polymerization tank, and the aggregate remains in the polyester, and there is a problem that foreign matter is generated in a molded product such as a film, a cup, and a sheet. In addition, the yellow color of the resin is discolored by the blue color of the cobalt compound, and therefore there is a problem that the transparency of the polyester is lowered.

Patent Document 1 describes that 50 to 95 mole% of the acid component constituting the polyester is terephthalic acid, 2 to 20 mole% is isophthalic acid, and 80 mole% or more of the glycol component is ethylene glycol. The polyester resin contains 0.1 to 1.0% by mass of methylene [3-methyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane. The content of the germanium compound is the acid component of the polyester resin in terms of 1 mole of 5 × 10 ^-5 mole mole ~ 3.0 × 10 ^-4, the content of cobalt compound for the acid component of the polyester resin in terms of 1 mole of 1 × 10 ^{- 5} to 2.0 × 10 ^-4 moles, and the content of the alkali metal compound is 1.0 × 10 ^-4 to 1.0 × 10 ^-3 moles of the polyester resin composition for the acid component 1 mole of the polyester resin. It is also described that the polyester resin composition does not cause whitening due to drawdown or crystallization during direct blow molding, and it also has excellent thermal stability. By using the polyester resin composition, production can be obtained Direct blow-molded article with good properties and excellent hue and transparency. However, the polyester resin composition may have insufficient impact resistance in addition to insufficient color tone or transparency of the obtained molded article. [Prior Art Literature] [Patent Literature]

[Patent Document 1] JP 2012-224836

[Problems Solved by the Invention]

The present invention has been made to solve the above-mentioned problems, and its object is to provide a polyester and a manufacturing method thereof that can obtain a molded product having excellent impact resistance in addition to high transparency and good color tone. [Means for solving problems]

The above-mentioned problem has been solved by providing a polyester containing 50 mol% or more of terephthalic acid units for the total of dicarboxylic acid units and 50 mol for the total of diol units. A polyester glycol unit of at least 1% of the above, the polyester is in a cobalt compound (M), at least one phosphorus compound (P) selected from the group consisting of phosphoric acid, phosphorous acid, organic phosphonic acid, and these esters, and α, In the presence of a polycarboxylic acid (X) in the β-dicarboxylic acid unit, a dicarboxylic acid and a diol are subjected to polycondensation. For a total of 100 parts by mass of the dicarboxylic acid, the addition amount of the cobalt compound (M) is cobalt The element conversion is 0.0005 to 0.05 parts by mass, the molar ratio (P / M) of the phosphorus atom in the phosphorus compound (P) of the cobalt atom in the cobalt compound (M) is 0.01 to 10, and the cobalt compound (M The molar ratio (X / M) of the polybasic carboxylic acid (X) of the cobalt atom in) is 0.01 to 10.

In this case, the phosphorus compound (P) is preferably at least one of phosphorous acid or phosphoric acid. The polycarboxylic acid (X) preferably has a hydroxyl group. The polycarboxylic acid (X) is preferably a tricarboxylic acid. It is particularly preferred that the polycarboxylic acid (X) is citric acid.

It is preferable that the content of the unit derived from the bisphenol A ethylene oxide adduct in the polyester is 0.1 to 20 mol% based on the total of the diol units. It is preferable that the content of the cyclohexanedimethanol unit in the polyester is 0.1 to 45 mol% based on the total of the diol unit. The content of the isophthalic acid unit in the polyester is preferably 0.1 to 20 mole% based on the total of the dicarboxylic acid units.

A molded article obtained by extruding the aforementioned polyester is a preferred embodiment of the present invention. A container made of the aforementioned molded article is a preferred embodiment of the present invention. In addition, a film or sheet made of the aforementioned molded product is also a preferred embodiment of the present invention, and a thermoformed product obtained by thermoforming the film or sheet is a more preferred embodiment.

A molded article obtained by thermoforming the polyester is also a preferred embodiment of the present invention.

The above problem is solved by providing a method for producing the aforementioned polyester by polycondensing a dicarboxylic acid and a diol in the presence of a cobalt compound (M), a phosphorus compound (P), and a polycarboxylic acid (X). . [Effect of the invention]

Since the cobalt compound (M) in the polyester of the present invention is uniformly dispersed and has less coarse aggregates, the color tone of the polyester is good. The molded product obtained by using such a polyester has high transparency and excellent impact resistance. . According to the production method of the present invention, such a polyester can be easily produced.

[Form of Invention]

The polyester of the present invention contains 50 mol% or more of terephthalic acid units for the total of dicarboxylic acid units, and 50 mol% or more of polyester glycol for the total of diol units. Unit; the polyester is a polybasic compound (M), at least one phosphorus compound (P) selected from the group consisting of phosphoric acid, phosphorous acid, organic phosphonic acid, and these esters, and a multicomponent having an α, β-dicarboxylic acid unit Dicarboxylic acid and diol are obtained by polycondensation in the presence of carboxylic acid (X); the amount of cobalt compound (M) added to 100 mass parts of total dicarboxylic acid is 0.0005 in the conversion of cobalt element ～ 0.05 parts by mass; the molar ratio (P / M) of the phosphorus atom in the phosphorus compound (P) to the cobalt atom in the cobalt compound (M) is 0.01 to 10; and the cobalt atom in the cobalt compound (M) The polyvalent carboxylic acid (X) has a molar ratio (X / M) of 0.01 to 10.

The content of the terephthalic acid (TA) unit in the polyester is 50 mol% or more with respect to the total of the dicarboxylic acid units. Here, the total of dicarboxylic acid units means the total of dicarboxylic acid units which do not have the α, β-dicarboxylic acid units in the polyester. When the polyester contains 50 mol% or more of terephthalic acid units, the melt viscosity can be moderated, and the impact resistance of the obtained molded product can be improved. In addition, thermal stability during molding can be improved. The content of the terephthalic acid unit is preferably 80 mol% or more.

The content of the ethylene glycol unit in the polyester is 50 mol% or more with respect to the total of the glycol units. Accordingly, when the polyester is produced, solid-phase polymerization can be performed at a high temperature, so that productivity can be improved and a molded product having a better color tone can be obtained. The content of the ethylene glycol unit is preferably 75 mol% or more. Generally, in the polyester obtained when ethylene glycol is used as a diol as a raw material, the diethylene glycol unit as a by-product in the polycondensation reaction contains 1 to 5 mol% of the total diol unit.

The structural unit contained in the aforementioned polyester may be a unit derived only from a polycarboxylic acid (X) having terephthalic acid units, ethylene glycol units, diethylene glycol units, and α, β-dicarboxylic acid units, However, the polyester may further contain an isophthalic acid (IPA) unit, and its content is preferably 0.1 to 20 mol% based on the total of the dicarboxylic acid units. The total of dicarboxylic acid units is the total of dicarboxylic acid units that do not contain the α, β-dicarboxylic acid units in the polyester. When the content of the isophthalic acid unit is 0.1 mol% or more, chemical resistance can be further improved. The content is preferably 2 mol% or more. On the other hand, when the content of isophthalic acid units exceeds 20 mol%, when it is solid-phase polymerized, sticking is likely to occur due to the softening of the resin, so the solid-phase polymerization temperature cannot be excessively high, so it is productive. Reduced concerns. The content of isophthalic acid units is preferably 15 mol% or less.

It is preferable that the polyester further contains a unit derived from a bisphenol A ethylene oxide adduct (EOBPA), and the content is preferably 0.1 to 20 mol% based on the total of the diol units. This can further improve the shrinkage resistance when the polyester is extruded. The bisphenol A ethylene oxide adduct is obtained by adding at least one ethylene oxide to each hydroxyl group of bisphenol A. The addition amount of ethylene oxide is usually 2 to 4 moles for bisphenol A1 mole.

From the viewpoint of obtaining the above effects, the unit content of the bisphenol A ethylene oxide adduct in the polyester is preferably 0.5 mol% or more, and more preferably 2 mol% or more. On the other hand, when the content is 20 mol% or less, the melt viscosity of the polyester can be moderated, and the impact resistance of the obtained molded product can be further improved. The aforementioned content is preferably 15 mol% or less, more preferably 10 mol% or less, and particularly preferably 8 mol% or less.

It is preferable that the polyester further contains a cyclohexanedimethanol (CHDM) unit, and the content thereof is preferably 0.1 to 45 mol% based on the total of the diol units. If the cyclohexanedimethanol unit in the aforementioned polyester is at least one selected from the group consisting of 1,2-cyclohexanedimethanol unit, 1,3-cyclohexanedimethanol unit, and 1,4-cyclohexanedimethanol unit, One kind of 2 price unit is sufficient. Among them, from the viewpoints of easy availability, easy formation of the aforementioned polyester into crystals, inconvenience of interparticle adhesion during solid-phase polymerization, and further improvement of impact resistance of the obtained molded product, cyclohexanedimethanol units 1,4-cyclohexanedimethanol units are preferred.

Although there are cis isomers and trans isomers in the cyclohexanedimethanol unit, the ratio of the cis isomer to the trans isomer of the cyclohexanedimethanol unit in the aforementioned polyester is the same. No special restrictions. Among them, when the cyclohexanedimethanol unit in the polyester is in a range of 0: 100 to 50:50, the ratio of the cis isomer to the trans isomer is likely to make the polyester crystalline, It is preferable from the viewpoints that adhesion between particles is less likely to occur during solid-phase polymerization, and the impact resistance of the obtained molded product is further improved.

When the polyester contains 0.1 mol% or more of cyclohexanedimethanol unit, the impact resistance of the obtained molded article at normal temperature and low temperature can be further improved, and transparency can also be improved. The aforementioned content is preferably 2 mol% or more, more preferably 4 mol% or more, and particularly preferably 6 mol% or more. On the other hand, if the content of the cyclohexanedimethanol unit is 45 mol% or less, a polyester having a high degree of polymerization can be obtained. The content is preferably 30 mol% or less. The content is more preferably 15 mol% or less. By subjecting the polyester having a content of 15 mol% or less to preliminary crystallization treatment, drying at a temperature higher than the glass transition temperature can be made possible, and the amount of water can be reduced, so it is possible to suppress Reduced limiting viscosity caused by hydrolysis.

The total content of the terephthalic acid unit and the ethylene glycol unit in the polyester is 50 mol% or more with respect to the total of the total structural units in the polyester. Accordingly, when the aforementioned polyester is produced by solid-phase polymerization, the adhesion by softening of the resin can be suppressed, so that the degree of polymerization can be easily increased. The aforementioned content is preferably 75 mol% or more, more preferably 85 mol% or more, and even more preferably 90 mol% or more.

The polyester may contain terephthalic acid units, ethylene glycol units, diethylene glycol units, isophthalic acid units, cyclohexanedimethanol units, and bisphenol A ethylene oxide addition if necessary. Comonomer units other than the units derived from the polycarboxylic acid (X) and the units of α, β-dicarboxylic acid.

The carbon number of other comonomer units is preferably 5 or more. If the number of carbons is less than 5, the comonomer boiling point of the raw material will be lowered and volatilized in the polycondensation reaction, and there is a concern that it becomes difficult to recover the diol. The upper limit of the number is not particularly limited, but is usually 50 or less. It may be one or more other comonomer units contained in the polyester.

As the other comonomer unit, a bifunctional compound unit is used as a main unit. The content of other bifunctional compound units (total if there are two or more units) The total structural unit constituting the polyester is preferably 20 mol% or less, and 10 mol% or less It is better to be less than 5 mole%. The other bifunctional compound units that can be contained in the polyester are terephthalic acid units, ethylene glycol units, diethylene glycol units, isophthalic acid units, cyclohexanedimethanol units, and bisphenol-derived units. A The units other than ethylene oxide adducts and α, β-dicarboxylic acid units other than dicarboxylic acids. If the other bifunctional compound unit is a dicarboxylic acid unit, a diol unit, or a hydroxycarboxylic acid unit, it may be an aliphatic bifunctional compound unit, an alicyclic bifunctional compound unit, or an aromatic bifunctional compound. Any unit.

Among users of other comonomer units, examples of the aromatic dicarboxylic acid unit include furan dicarboxylic acid (FDCA), phthalic acid, 5- (alkali metal) sulfoisophthalic acid, and dibenzene. Formic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5naphthalenedicarboxylic acid, 2,6naphthalenedicarboxylic acid, 2,7naphthalenedicarboxylic acid, 4, 4 Aromatic dicarboxylic acids such as' -biphenyldicarboxylic acid, 4,4'-biphenylphosphonium dicarboxylic acid, 4,4'-biphenyl ether dicarboxylic acid, paranaphthoic acid, and anthracenedicarboxylic acid Or units of these ester-forming derivatives.

Among users of other comonomer units, examples of the aliphatic dicarboxylic acid unit include dimer acid, hydrogenated dimer acid, oxalic acid, malonic acid, glutaric acid, adipic acid, and heptane. Diacid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanoic acid, hexadecanedioic acid , Aliphatic dicarboxylic acids such as heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, arcosenedioic acid, behenedioedioic acid, fumaric acid, itaconic acid, 1,1 -Cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid Acid, 1,3-cyclohexanedicarboxylic acid, decahydronaphthalenedicarboxylic acid (decahydronaphthalenedicarboxylic acid), tetrahydronaphthalenedicarboxylic acid, cyclobutenedicarboxylic acid, tricyclodecanedicarboxylic acid, Units of aliphatic dicarboxylic acids such as norbornane dicarboxylic acid and adamantane dicarboxylic acid, or these ester-forming derivatives.

Among other users of the comonomer unit, the aliphatic diol unit includes triethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediamine. Alcohol, 1,6-hexanediol, isosorbide, 1,2-propanediol, neopentyl glycol (2,2-dimethyl-1,3-propanediol), 3-methyl-1 1,5-pentanediol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, tetramethylcyclobutanediol, 1,9-nonanediol, dimer dimer with 36 carbon atoms Units of aliphatic diols such as alcohols and dimer diols having 44 carbon atoms, or these ester-forming derivatives.

Among other users of the comonomer unit, examples of the hydroxycarboxylic acid include aliphatic hydroxycarboxylic acids such as 10-hydroxyoctadecanoic acid or these ester-forming derivatives; hydroxymethylcyclohexanecarboxylic acid, hydroxy Alicyclic hydroxycarboxylic acids such as methyl norbornenecarboxylic acid, hydroxymethyltricyclodecanecarboxylic acid or these ester-forming derivatives; hydroxybenzoic acid, hydroxybenzoic acid, hydroxynaphthoic acid, 3- (hydroxyphenyl ) Aromatic hydroxycarboxylic acids such as propionic acid, hydroxyphenylacetic acid, 3-hydroxy-3-phenylpropionic acid, and these ester-forming derivatives.

The aforementioned polyester may be in a range that does not hinder the effect of the present invention. As other comonomer units, in addition to units derived from polycarboxylic acid (X) having α, β-dicarboxylic acid units, units having A polyfunctional compound unit derived from a polyfunctional compound having three or more carboxyl groups, hydroxyl groups, and / or these ester-forming groups. By containing such a polyfunctional compound unit in the polyester, the expandability can be improved. The content of other polyfunctional compound units (the total is the case when there are two or more units). For the total of the aforementioned structural units of the polyester, 0.00005 to 1 mole% is preferred, and 0.00015 to 0.8 mole % Is more preferred, and 0.00025 to 0.4 mole% is more preferred. Among other polyfunctional compound units, trifunctional compound units and tetrafunctional compound units are also preferable. As other polyfunctional compound units, polycarboxylic acid units derived from trimellitic acid, trimesic acid, and the like; polyhydric alcohol units derived from trimethylolpropane, glycerol, and the like are preferred.

The polyfunctional compound unit is a carboxylic acid ester of a trivalent or higher polyhydric alcohol, and examples thereof include a unit derived from a polyvalent ester in which the carboxylic acid has a hindered phenol group. Examples of the polyvalent ester include pentaerythritol [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-ginseng [2- [3- ( 3,5-di-tert-butyl-4-hydroxyphenyl) propanyloxy] ethyl] hexahydro-1,3,5-triazine-2,4,6-trione and the like.

If necessary, the polyester may have a monofunctional compound unit derived from at least one monofunctional compound of a monocarboxylic acid, a monoalcohol, and these ester-forming derivatives as other comonomer units. The monofunctional compound unit can perform its function as a sealing compound unit. Sealing of molecular chain end groups and / or branched chain end groups in the aforementioned polyesters prevents excessive crosslinking and gel generation in the aforementioned polyesters. . If the polyester has such a monofunctional compound unit, the content of the monofunctional compound unit (the total amount when there are two or more units) is 1 mol for the total of the total structural units of the polyester. % Or less is preferred, and 0.5 mole or less is more preferred. When the content of the monofunctional compound unit in the polyester is more than 1 mol%, the polymerization rate at the time of manufacturing the polyester is slowed, and the productivity is liable to decrease. Examples of the monofunctional compound unit include units derived from a monofunctional compound selected from the group consisting of benzoic acid, 2,4,6-trimethoxybenzoic acid, 2-naphthoic acid, stearic acid, and stearyl alcohol. Wait.

The polyester is a cobalt compound (M), at least one phosphorus compound (P) selected from the group consisting of phosphoric acid, phosphorous acid, organic phosphonic acid, and these esters, and a polycarboxylic acid having an α, β-dicarboxylic acid unit. (X) A product obtained by polycondensing a dicarboxylic acid and a diol. However, the aforementioned dicarboxylic acid of the raw material monomer does not have an α, β-dicarboxylic acid unit.

In this way, at the time of polycondensation, by using the cobalt compound (M), at least one phosphorus compound (P) selected from the group consisting of phosphoric acid, phosphorous acid, organic phosphonic acid, and these esters, and having α, β-di The polycarboxylic acid (X) of a carboxylic acid unit can obtain a polyester with favorable color tone. Furthermore, by using this polyester, a molded article having high transparency and excellent impact resistance can be obtained. Therefore, it is considered that the dispersibility of the cobalt compound (M) can be improved by using the phosphorus compound (P) and the polycarboxylic acid (X). It can be considered that since the cobalt compound (M) can be uniformly dispersed in the aforementioned polyester, the hue improvement effect by the cobalt compound (M) can be efficiently achieved, and the decrease in transparency by the cobalt compound (M) can be suppressed at the same time. . In addition, it is thought that the generation of coarse aggregates of the cobalt compound (M) is suppressed, and the impact resistance of the obtained molded product is improved. In addition, the aggregate of the cobalt compound generated during the polycondensation can be removed in a filter. However, this filter causes clogging in a short time and reduces productivity. In contrast, since the cobalt compound (M) in the polyester of the present invention has less coarse aggregates, it is possible to increase the filter exchange interval and improve productivity.

Examples of the cobalt compound (M) used in the present invention include cobalt salts of organic acids such as cobalt acetate, cobalt oxide, and the like. Among them, cobalt acetate is also considered to be soluble in alcohol and easy to handle during production. good. The addition amount of the cobalt compound (M) is 0.0005 to 0.05 parts by mass in terms of cobalt based on 100 parts by mass of the total of dicarboxylic acids. Here, the total of dicarboxylic acid units is the total of dicarboxylic acid units which do not have α, β-dicarboxylic acid units in the polyester. For the total 100 parts by mass of dicarboxylic acid during the polymerization, by adding 0.0005 parts by mass or more of the cobalt compound (M), the hue of the obtained polyester can be improved, and the molded product obtained by using the polyester can be improved. Shock resistance. The addition amount of the cobalt compound (M) is preferably 0.001 parts by mass or more, and more preferably 0.002 parts by mass or more. On the other hand, when the total amount of the cobalt compound (M) is 0.05 parts by mass or less with respect to 100 parts by mass of the dicarboxylic acid during polymerization, the polymerization reaction is not hindered. The addition amount of the cobalt compound (M) is preferably 0.02 parts by mass or less.

For the present invention, a cobalt compound (M) and a polycarboxylic acid (X) having an α, β-dicarboxylic acid unit are used simultaneously during the polycondensation. It is considered that the polycarboxylic acid (X) having an α, β-dicarboxylic acid unit easily interacts with the cobalt compound (M), and this is considered to be one of the factors for improving the dispersibility of the cobalt compound (M). From the viewpoint of further improving the dispersibility of the cobalt compound (M), the polycarboxylic acid (X) preferably has a hydroxyl group. From the same viewpoint, it is preferable that the polycarboxylic acid (X) is a tricarboxylic acid. Examples of the polycarboxylic acid (X) having an α, β-dicarboxylic acid unit include citric acid, tartaric acid, succinic acid, fumaric acid, and maleic acid. Among them, citric acid, tartaric acid, and succinic acid are preferred. Citric acid and succinic acid are preferred, and citric acid is more preferred. The polycarboxylic acid (X) having an α, β-dicarboxylic acid unit or at least a part of the decomposition product is contained in the main chain, branched chain, or terminal of the aforementioned polyester.

When the polycondensation is performed, it is desired to adjust the amount of the polycarboxylic acid (X) to which the molar ratio (X / M) of the polycarboxylic acid (X) of the cobalt atom in the cobalt compound (M) is 0.01 to 10. When the molar ratio (X / M) is set to 0.01 or more, the dispersibility of the cobalt compound (M) in the polyester is improved. The molar ratio (X / M) is preferably 0.1 or more, more preferably 0.5 or more, and more preferably 1 or more. On the other hand, when the molar ratio (X / M) is 10 or less, in addition to not hindering the polymerization reaction, the hue of the resin or the transparency of the molded article can be improved. The molar ratio (X / M) is preferably 5 or less.

In the present invention, at the time of polycondensation, a cobalt compound (M) is used together with at least one phosphorus compound (P) selected from the group consisting of phosphoric acid, phosphorous acid, organic phosphonic acid, and these esters. The phosphoric acid used as the phosphorus compound (P) may be orthophosphoric acid or polyphosphoric acid such as pyrophosphoric acid. The phosphoric acid ester used as the phosphorus compound (P) is preferably a monoester or diester of the aforementioned phosphoric acid and an aliphatic monoalcohol having 1 to 20 carbon atoms, and dibutyl phosphate, diethyl phosphate, and dimethyl phosphate are preferred. The base is better. The phosphorous acid ester used as the phosphorus compound (P) is preferably a monoester of phosphorous acid and an aliphatic monoalcohol having 1 to 20 carbon atoms. The organic phosphonic acid used as the phosphorus compound (P) is preferably an alkylphosphonic acid. The number of carbon atoms of the alkyl group directly bonded to the phosphorus atom in the alkylphosphonic acid is preferably from 1 to 20. The organic phosphonate used as the phosphorus compound (P) is preferably a monoester of the aforementioned organic phosphonic acid and an aliphatic monoalcohol having 1 to 20 carbon atoms. Among them, it is also preferable that the phosphorus compound (P) used in the present invention is at least one of phosphorous acid or phosphoric acid, and phosphorous acid is more preferable.

When the polycondensation is performed, the molar ratio (P / M) of the phosphorus atom in the phosphorus compound (P) to the cobalt atom in the cobalt compound (M) is adjusted to 0.01 to 10 and the amount of the phosphorus compound (P) to be added is adjusted. . When the molar ratio (P / M) is 0.01 or more, the color tone of the obtained polyester becomes good. Moreover, the thermal stability of the molded article obtained using the said polyester can be improved by the oxidation prevention effect of a phosphorus compound (P). The molar ratio (P / M) is preferably 0.1 or more, more preferably 1 or more, and even more preferably 1.5 or more. On the other hand, when the molar ratio (P / M) is 10 or less, the polymerization reaction is not hindered. The molar ratio (P / M) is preferably 5 or less.

Polycondensation of a dicarboxylic acid (a dicarboxylic acid without an α, β-dicarboxylic acid unit) and a diol in the presence of a cobalt compound (M), a phosphorus compound (P), and a polycarboxylic acid (X) The method is not particularly limited, and terephthalic acid, ethylene glycol, or these ester-forming derivatives and optionally cyclohexanedimethanol, bisphenol A ethylene oxide adduct, isophthalic acid, and others can be used. As a raw material, the method of melt-condensing the obtained polyester oligomer after esterification reaction or transesterification reaction is mentioned as a raw material. There are no particular restrictions on the point in time when the cobalt compound (M), phosphorus compound (P), and polycarboxylic acid (X) are added. They can be added before or after the esterification reaction or transesterification reaction. Those are better. The cobalt compound (M), the phosphorus compound (P), and the polycarboxylic acid (X) may be added individually, or at least two kinds of the cobalt compound (M), the phosphorus compound (P), and the polycarboxylic acid (X) may be mixed in advance. , And then add the resulting mixture to other raw materials.

The polyvalent ester may be added before an esterification reaction or a transesterification reaction, or may be added after these reactions are performed. In addition, other raw materials or polymerization catalysts may be appropriately added before the esterification reaction or transesterification reaction is performed, or after these reactions are performed.

The above-mentioned esterification reaction or transesterification reaction is to load a cobalt compound (M), a phosphorus compound (P), a polycarboxylic acid (X), a raw material monomer, a polymerization catalyst, and other additives described later as necessary into a reactor, and Under pressure or normal pressure of about 0.5 MPa or less and at a temperature of 160 to 280 ° C, it is preferable to perform the distillation while distilling off the generated water or alcohol.

Following the esterification reaction or transesterification reaction, the melt polycondensation reaction is continued. To the obtained polyester oligomer, a cobalt compound (M), a phosphorus compound (P), a polycarboxylic acid (X), and a raw material monomer are added as necessary. The polycondensation catalyst and other additives described later are preferably carried out under a reduced pressure of 1 kPa or less at a temperature of 260 to 290 ° C until a polyester having a desired viscosity is obtained. If the reaction temperature of the melt polycondensation reaction is less than 260 ° C, the polymerization activity of the polymerization catalyst is low, and there is a concern that a polyester having a desired degree of polymerization cannot be obtained. On the other hand, if the reaction temperature of the melt polymerization reaction exceeds 290 ° C, the decomposition reaction becomes easier, and as a result, there is a concern that a polyester having a desired degree of polymerization cannot be obtained. The melt polycondensation reaction can be performed using, for example, a tank type batch type polycondensation device, a continuous type polycondensation device formed by a two-axis rotary horizontal reactor, and the like.

As the polymerization catalyst used for the above-mentioned polycondensation, any catalyst used in polyester production can be selected, but a compound containing a germanium element or an antimony element is preferred. Among them, from the viewpoints of polymerization catalyst activity, physical properties and cost of the obtained polyester, germanium dioxide and antimony trioxide are preferable, and the former are more preferable from the viewpoint of transparency and color tone. When a polycondensation catalyst is used, the added amount is preferably within a range of 0.002 to 0.8% by mass based on the mass of the dicarboxylic acid (dicarboxylic acid having no α, β-dicarboxylic acid unit) component.

The limiting viscosity of the polyester obtained by melt polycondensation is preferably 0.4 dl / g or more. Thereby, the handleability can be improved, and when the polyester obtained by the melt polycondensation is further solid-phase polymerized, the polymer can be quantified in a short period of time, thereby improving the productivity. The aforementioned limiting viscosity is preferably 0.55 dl / g or more, and more preferably 0.65 dl / g or more. On the other hand, from the viewpoint that the polyester can be easily taken out from the reactor or that the coloration can be suppressed by thermal degradation, the limiting viscosity is preferably 0.9 dl / g or less, more preferably 0.85 dl / g or less, and more It is preferably 0.8 dl / g or less.

The polyester thus obtained can be suitably used as a raw material for extrusion molding and the like. It is also preferable to further solid-state polymerize the polyester obtained by melt polycondensation. This solid phase polymerization will be described below.

Extruding the polyester obtained in the shape of a strand, a sheet, etc., after cooling, cutting with a strand cutter or a slice cutter, etc., to produce a cylindrical shape, a cylindrical shape, a disc shape, Intermediate particles in the shape of a dice. The aforementioned cooling after extrusion can be performed by, for example, a water cooling method using a water tank, a method using a cooling tank, an air cooling method, or the like.

In order to further increase the degree of polymerization of the obtained intermediate particles, solid phase polymerization is performed. It is preferable that a part of the polyester is crystallized in advance by heating before solid-phase polymerization. By doing so, it is possible to prevent the particles from sticking during the solid phase polymerization. The crystallization temperature is preferably 100 to 180 ° C. As a crystallization method, crystallization can be performed in a vacuum drum mixer (Tumbler), or it can be crystallized by heating in an air circulation heating device. When heating in an air circulation heating device, it is preferable to set the internal temperature to 100 to 160 ° C. Compared with crystallization using a vacuum drum mixer (Tumbler) for heating using an air circulation heating device, since the heat conduction is good, the time required for crystallization can be shortened and the device is cheap. Although the time required for crystallization is not particularly limited, it is usually about 30 minutes to 24 hours. Crystallization may also be performed in advance, and it is preferable to dry the particles at a temperature of less than 100 ° C.

The temperature of the solid phase polymerization is preferably 170 to 250 ° C. When the temperature of the solid-phase polymerization is less than 170 ° C, the time of the solid-phase polymerization may become longer, and there is a concern that productivity may be reduced. The temperature of the solid phase polymerization is preferably 175 ° C or higher, and more preferably 180 ° C or higher. On the other hand, if the temperature of the solid phase polymerization exceeds 250 ° C., the particles are likely to stick. The temperature of the solid phase polymerization is preferably 240 ° C or lower, and more preferably 230 ° C or lower. The time for the solid phase polymerization is usually about 5 to 70 hours.

The solid phase polymerization is preferably performed under reduced pressure or in an inert gas such as nitrogen. In addition, in order to prevent the occurrence of inter-particle agglomeration, the particles may be moved by an appropriate method such as a rotation method or a gas-fluidized bed method, and solid-phase polymerization may be performed. The pressure when the solid phase polymerization is performed under reduced pressure is preferably 1 kPa or less.

The polyester obtained by such solid phase polymerization can be used as an extrusion molding material, and is particularly suitable as a raw material for extrusion blow molding.

The polyester obtained as described above may contain other additives as long as it does not hinder the effects of the present invention. Examples thereof include stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, and flame retardant assistance. Additives, lubricants, plasticizers, inorganic fillers, etc. The content of these additives in the polyester is preferably 10% by mass or less, and more preferably 5% by mass or less.

The limiting viscosity of the polyester obtained by solid phase polymerization is preferably 0.9 dl / g or more. This makes it possible to further improve the shrinkage resistance of the polyester during extrusion blow molding. The aforementioned limiting viscosity is preferably 1.0 dl / g or more, and more preferably 1.05 dl / g or more. On the other hand, the aforementioned limiting viscosity is preferably 1.5 dl / g or less, more preferably 1.4 l / g or less, and even more preferably 1.3 l / g or less.

By melt-molding the obtained polyester, various molded products can be obtained. A molded product obtained by melt-molding the polyester of the present invention has good color tone, high transparency, and high impact strength.

Although the limiting viscosity of the aforementioned polyester provided for melt molding is not particularly limited, from the viewpoint of further improving the strength, impact resistance, melt moldability, and production stability of the obtained molded product, it is preferably 0.55 dl / g or more. It is preferably 0.65 dl / g or more. On the other hand, from the viewpoint of further improving melt formability or productivity, the limiting viscosity is preferably 1.5 dl / g or less, more preferably 1.4 dl / g or less, and even more preferably 1.3 dl / g or less. The total light transmittance of the molded product is preferably 90.3% or more, more preferably 90.5% or more, and even more preferably 90.7% or more. By using the polyester, a molded article having such excellent transparency can be obtained. The melt-molded article is further subjected to secondary processing to obtain a molded article.

The molding method is not particularly limited, but an extrusion molding method is preferably used. The aforementioned molded product obtained by extruding the polyester is a preferred embodiment of the present invention. The aforementioned film or sheet obtained by extrusion molding of polyester is a preferred embodiment of the present invention. In addition, the aforementioned container formed by extruding polyester is also a preferred embodiment of the present invention. The aforementioned polyester has a high viscosity during melt molding, and is therefore suitable for extrusion molding. The temperature of the resin composition at the time of extrusion molding is preferably in the range of (melting point of polyester + 10 ° C) to (melting point of polyester + 70 ° C), and (melting point of polyester + 10 ° C) to (poly The temperature is preferably within the range of the melting point of the ester + 40 ° C. When extrusion is performed at a temperature relatively close to the melting point, drawdown can be suppressed.

By using the aforementioned polyester, for example, when a sheet or film is manufactured by extrusion molding such as a T-die method or an inflation method, a sheet or film having high transparency and high quality can be produced with better productivity. When using the thus obtained sheet or film for secondary processing such as thermoforming, when molding into a deep-drawn molded product or a large-sized molded product, the mold temperature can be adjusted according to the application, and the degree of crystallization of the molded product can be adjusted. In addition, when the film is biaxially stretched, crystallinity can be improved, and the strength of the stretched film can be improved. A thermoformed product obtained by thermoforming a biaxially stretched film, sheet or film in this way, wherein a container formed by thermoforming the aforementioned sheet or film is a preferred embodiment of the present invention.

In the extrusion molding, the above-mentioned polyester is particularly suitable for extrusion blow molding. The method of extrusion blow molding is not particularly limited, and the same method can be performed as the conventionally known extrusion blow molding method. For example, the above-mentioned polyester can be melt-extruded to form a cylindrical parison. While the parison is in a softened state, it can be clamped with a blow mold, and air or other gas can be blown into the parison along the cavity. The method is performed by expanding the shape into a predetermined hollow shape. When the polyester is used, a foreign material that is hard to aggregate with a cobalt compound is hard to be produced, so that a molded product can be produced in a high yield.

The molded product obtained by extruding the aforementioned polyester through extrusion molding is also a preferred embodiment of the present invention. This molded article has good transparency, color tone, and impact resistance. Therefore, this molded article can be used for various applications. The container formed from the aforementioned molded article is a preferred embodiment of the molded article. Such a container can be used as a container for cosmetics or oil. In addition, it may be a molded article having a laminated structure such as the polyester and other thermoplastic resins. [Example]

Hereinafter, the present invention is further described in detail through examples, but the present invention is not limited by these examples.

(1) Composition of polyester The ratio of monomer units constituting the polyester was determined by ¹ H-NMR spectrum (apparatus: "JNM-GX-500 model" manufactured by Japan Electronics Corporation, solvent: dehydrogenated trifluoroacetic acid). Evaluation. (2) Limit viscosity (IV) The limit viscosity of the polyester after melt polymerization and the polyester after solid phase polymerization are not available. A mass mixture of phenol and 1,1,2,2-tetrachloroethane is used as a solvent. It was measured at a temperature of 30 ° C.

(3) The particle diameter distribution is 500 g of a mass mixture of phenol and 1,1,2,2-tetrachloroethane, which is filtered by a filter with a pore size of 1 micron. 0.4 g of crystalline particles after solid phase polymerization is at 100 ° C. The solution was dissolved and allowed to stand at room temperature for 1 day. A 50 mL (65 g) solution was passed through a particle counter in liquid (Accuizer 780SIS, manufactured by Particle Sizing Systems), and the range of 0.5 to 500 μm was divided into 128 for logarithmic measurement. The particle number distribution contained in the particles was determined. The measurement was performed 3 times to obtain an average value. As an example of the particle diameter distribution in the polyester, the particle diameter distribution in the polyester obtained in Example 2 and Comparative Example 1 is shown in FIG. 1. The number of particles having a particle size of 5 μm or more contained in 1 g of the particles thus measured serves as an index of the dispersibility of the cobalt compound (M). (4) The number of foreign particles in the film after solid-phase polymerization is dried at 120 ° C overnight, and a 20φ single-shaft extruder is used (cylinder temperature: 280-290 ° C, cooling roll temperature: 80 ° C), A polyester resin film was extruded from a T-die onto a cooling roller to form a film with a thickness of 400 μm. Using a sheet defect detector (ZD-CMAP manufactured by Frontier Systems), each foreign object was measured at 20 μm or more and less than 60 μm. And the number of foreign objects above 60 μm.

(5) Total light transmittance A sample (3 cm in length, 3 cm in width, and 0.8 mm in thickness) was cut out from the body of the formed transparent bottle, and the total light was measured using a haze meter (HR-100 manufactured by Murakami Color Technology Research Institute). Transmittance.

(6) IZOD impact strength After the solid-phase polymerized particles were dried at 120 ° C overnight, injection test molding was used to produce test pieces with a length of 80 mm, a width of 10 mm, and a thickness of 4 mm. Each 10 samples were trapped. Wave processing. After the test piece was stored at 23 ° C for 48 hours, the IZOD impact strength was measured using a hammer with a nominal pendulum energy of 0.5 J at a lifting angle of 150 degrees. The average value of the test results of each sample 10 times was taken as the IZOD impact strength, and the impact resistance was evaluated.

(7) Dropping strength of the bottle After putting water into the bottle with a total weight of 263g ± 0.5g (water temperature 20 ~ 25 ° C), the bottle is set to a vertical 10cm diameter cylinder, and the height is from 125cm to the horizontal concrete. The surface falls into a 45-degree inclined concrete surface to interact and fall. The number of cycles until the bottle was broken or cracked was measured (1 cycle each time, the bottle was once on a horizontal plane, and dropped once on a 45-degree inclined plane, a total of 2 times). Repeat to a maximum of 20 cycles. For each composition, a drop test was performed on 5 bottles, and the average value was used as the bottle drop strength. As an indicator of the impact resistance of the molded product.

(8) Hue The hue (b value) of the polyester resin particles was measured in accordance with ASTM-D2244 (color scale system 2) using a color measurement colorimeter "ZE-2000" manufactured by Nippon Denshoku Industries Co., Ltd.

Example 1 (1) Melt polycondensation produced 100 parts by mass of terephthalic acid (TA), 42.6 parts by mass of ethylene glycol (EG), and 2 mols of bisphenol A ethylene oxide (EOBPA) 9.5 Parts by mass, 0.0123 parts by mass of germanium dioxide (GeO ₂ ), 0.0123 parts by mass of phosphorous acid as a phosphorus compound (P), and 0.0130 parts by mass of cobalt acetate osmium tetrahydrate as a cobalt compound (M) 0.0031 parts by mass), and a slurry of 0.0109 parts by mass of rhenium citrate monohydrate as a polycarboxylic acid (X), under pressure (0.25 MPa gauge) and heated at 250 ° C. to perform an esterification reaction. An oligomer is then produced. The obtained oligomer was transferred to a polycondensation tank, and melt polycondensation was performed at 0.1 kPa at 260 ° C to 280 ° C for 80 minutes to produce a polyester having a limiting viscosity of 0.7 dL / g. The obtained polyester was extruded into a strand shape from a nozzle and water-cooled, and then cut into a cylindrical shape (about 2.5 mm in diameter and about 2.5 mm in length) to obtain amorphous particles of polyester. (2) Preliminary crystallization of amorphous particles The obtained amorphous particles of polyester were put into a rotary vacuum solid-phase polymerization apparatus, and preliminary crystallization was performed at 120 ° C for 2 hours at 0.1 kPa.

(3) Solid-phase polymerization After the aforementioned preliminary crystallization, the temperature was raised, and solid-phase polymerization was performed at 190-200 ° C for 40 hours at 0.1 kPa to obtain crystal particles. When the ratio of the monomer components constituting the polyester was confirmed by a ¹ H-NMR spectrum (apparatus: "JNM-GX-500 type manufactured by Japan Electronics Co., Ltd., solvent: deuterated trifluoroacetic acid), it was TA. Unit: EG unit: EOBPA unit: Diethylene glycol (DEG) unit = 100: 93: 5: 2 (Molar ratio). The limiting viscosity of the obtained polyester resin was 1.2 dL / g, and the b value of the obtained polyester resin was -2.0. The number of particles of 5 μm or more contained in 1 g of the obtained polyester was 229 particles / g when measured by a liquid particle counter. When the number of foreign materials in the film was measured, the number of foreign materials was 20 μm or more and less than 60 μm was 190 / m ² , and the number of foreign materials 60 μm or more was 10 / m ² . The IZOD impact strength is 4.5 kJ / m ² .

(4) Bottle production After drying the obtained granules at 120 ° C for 24 hours using a dehumidifying dryer, an extrusion blow molding apparatus ("MSE-40E type" manufactured by Tahara Co., Ltd.) was used to form a transparent 220mL volume. Bottle (27g). At this time, the cylinder temperature is set to a gradient from 280 ° C to 240 ° C, the nozzle temperature is set to 240-250 ° C, the forming cycle is 10 seconds, the number of screw rotations is 24 rpm, and the model temperature is 20 ° C. When the drop strength of the bottle was investigated, the drop strength of the bottle was 14. The total light transmittance of the molded product was 91.0%.

Example 2 A polyester produced in the same manner as in Example 1 was evaluated except that the addition amount of the europium citrate monohydrate was changed to 0.0154 parts by mass. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 3 以外 The addition amount of osmium citrate monohydrate was changed to 0.0861 parts by mass, and the polyester resin produced in the same manner as in Example 1 was evaluated. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 4: The addition amount of osmium citrate monohydrate was changed to 0.0006 parts by mass, and the polyester resin produced in the same manner as in Example 1 was evaluated. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 5 A polyester resin produced in the same manner as in Example 2 was evaluated except that 0.0144 parts by mass of phosphoric acid was added instead of phosphorous acid. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 6 The slurry of the raw material was changed from 86 parts by mass of terephthalic acid, 14 parts by mass of isophthalic acid (IPA), 44.8 parts by mass of ethylene glycol, 0.0123 parts by mass of germanium dioxide, 0.0123 parts by mass of phosphorous acid, and acetic acid. A polyester was produced in the same manner as in Example 1 except that the sludge formed by cobalt osmium tetrahydrate and 0.01154 parts by mass of osmium citrate monohydrate was changed to a temperature of 180 to 190 ° C. The polyester was obtained in the same manner as in Example 1 except that the molding cycle at the time of bottle molding was changed to 7 seconds. Among the monomer components constituting the polyester, TA unit: IPA unit: EG unit: DEG unit = 86: 14: 98: 2 (Molar ratio). The results are summarized in Table 1.

Example 7 The raw material slurry was changed from 100 parts by mass of terephthalic acid, 12.2 parts by mass of 1,4-cyclohexanedimethanol (CHDM), 38.5 parts by mass of ethylene glycol, and 0.0123 parts by mass of germanium dioxide (GeO ₂ ). Parts, 0.0123 parts by mass of phosphorous acid, 0.0130 parts by mass of cobalt acetate osmium tetrahydrate (0.0031 parts by mass in terms of cobalt), and 0.0154 parts by mass of osmium citrate monohydrate, the solid-phase polymerization temperature was changed to 180 to Except for 190 ° C, the polyester produced in the same manner as in Example 1 was evaluated. Among the monomer components constituting the polyester, TA unit: EG unit: CHDM unit: DEG unit = 100: 84: 14: 2 (Molar ratio). The results are summarized in Table 1.

Example 8 A polyester was manufactured and evaluated in the same manner as in Example 1 except that 0.0086 parts by mass of succinic acid was added instead of osmium citrate monohydrate. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 9 A polyester was produced and evaluated in the same manner as in Example 1 except that the amount of rhenium substituted rhenium citrate monohydrate was 0.0065 parts by mass of tartaric acid. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 10 The same procedure as in Example 2 was performed except that the addition amount of cobalt acetate ･ tetrahydrate was changed to 0.0026 parts by mass (0.0006 parts by mass in terms of cobalt element conversion) and the addition amount of phosphorous acid was changed to 0.0062 parts by mass. Ester and evaluated. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 11 The same procedure as in Example 2 was performed except that the addition amount of cobalt acetate and osmium tetrahydrate was changed to 0.0615 parts by mass (0.0146 parts by mass in terms of cobalt), and the addition amount of phosphorous acid was changed to 0.0246 parts by mass. Ester and evaluated. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 12 (I) A polyester was produced and evaluated in the same manner as in Example 2 except that the amount of phosphorous acid added was changed to 0.0062 parts by mass. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Example 13 A polyester was produced and evaluated in the same manner as in Example 2 except that 0.0615 parts by mass of dibutyl phosphate was added instead of phosphorous acid. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 1.

Comparative Example 1 A polyester was produced and evaluated in the same manner as in Example 1 except that osmium citrate monohydrate was not added. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 2.

Comparative Example 2 A polyester was produced and evaluated in the same manner as in Example 1 except that the addition amount of europium citrate monohydrate was changed to 0.00006 parts by mass. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 2.

Comparative Example 3 以外 A polyester was produced and evaluated in the same manner as in Example 1 except that the addition amount of osmium citrate monohydrate was changed to 0.369 parts by mass and the point where the solid-layer polymerization time was changed to 100 hours. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 2.

Comparative Example 4 A polyester was produced and evaluated in the same manner as in Example 2 except that phosphorous acid was not added. Among the monomer components constituting the polyester, TA units: EG units: EOBPA units: DEG units = 100: 93: 5: 2 (mole ratio) are summarized in Table 2.

Comparative Example 5 A polyester was produced and evaluated in the same manner as in Example 6 except that osmium citrate monohydrate was not added. Among the monomer components constituting the polyester, TA unit: IPA unit: EG unit: DEG unit = 86: 14: 98: 2 (Molar ratio). The results are summarized in Table 2.

Comparative Example 6 A polyester was produced and evaluated in the same manner as in Example 7 except that osmium citrate monohydrate was not added. Among the monomer components constituting the polyester, TA unit: EG unit: CHDM unit: DEG unit = 100: 84: 14: 2 (Molar ratio). The results are summarized in Table 2.

Comparative Example 7 A polyester was produced and evaluated in the same manner as in Example 1 except that 0.0065 parts by mass of lactic acid was added instead of rhenium citrate monohydrate. Among the monomer components constituting the polyester, TA unit: EG unit: EOBPA unit: DEG unit = 100: 93: 5: 2 (Molar ratio). The results are summarized in Table 2.

FIG. 1 is a graph showing particle size distribution in the polyester obtained in Example 2 and Comparative Example 1. FIG.

Claims (13)

A polyester containing 50 mol% or more of terephthalic acid units for the total of dicarboxylic acid units and 50 mol% or more of ethylene glycol for polyesters , Characterized in that the polyester is a cobalt compound (M), at least one phosphorus compound (P) selected from the group consisting of phosphoric acid, phosphorous acid, organic phosphonic acid and their esters, and α, β-dicarboxylate In the presence of a polycarboxylic acid (X) in an acid unit, a polycondensation of a dicarboxylic acid and a diol is obtained. For a total of 100 parts by mass of the carboxylic acid, the addition amount of the cobalt compound (M) is calculated in terms of cobalt. 0.0005 to 0.05 parts by mass, the mole ratio (P / M) of rhenium to the phosphorus atom in the cobalt compound (M) in the cobalt compound (M) is 0.01 to 10, and in the cobalt compound (M) The molar ratio (X / M) of the cobalt atom-containing polycarboxylic acid (X) is 0.01 to 10. The polyester according to claim 1, wherein the phosphorus compound (P) is at least one of phosphorous acid or phosphoric acid. The polyester as claimed in claim 1 or 2, wherein the polycarboxylic acid (X) has a hydroxyl group. The polyester of claim 1 or 2, wherein the polycarboxylic acid (X) is a tricarboxylic acid. The polyester of claim 1 or 2, wherein the polycarboxylic acid (X) is citric acid. For example, the polyester of claim 1 or 2 further contains a unit derived from a bisphenol A ethylene oxide adduct in an amount of 0.1 to 20 mol% based on the total of the aforementioned diol units. For example, the polyester of claim 1 or 2 further contains a cyclohexanedimethanol unit of 0.1 to 45 mole% with respect to the total of the aforementioned diol units. For example, the polyester of claim 1 or 2 further contains an isophthalic acid unit of 0.1 to 20 mol% with respect to the total of the aforementioned dicarboxylic acid units. A molded article, which is formed by extruding the polyester according to any one of claims 1 to 8. A film or sheet characterized by being formed from a molded article as claimed in claim 9. A thermoformed product, characterized in that a film or sheet as claimed in claim 10 is thermoformed. A container characterized by being formed from a molded article as claimed in claim 9. The method for producing a polyester according to any one of claims 1 to 8, comprising polymerizing a dicarboxylic acid and a diol in the presence of a cobalt compound (M), a phosphorus compound (P), and a polycarboxylic acid (X). Condenser.