JP4529590B2 - Polyester resin and method for producing the same - Google Patents

Description

  The present invention relates to a polyester resin and a method for producing the same, and more specifically, a polyester resin having various physical properties and color tone suitable for various uses such as a container such as a bottle, a film, a sheet, and a fiber, and the polyester resin. Regarding the method.

  Conventionally, polyester resins, especially polyethylene terephthalate resin produced using terephthalic acid and ethylene glycol as raw materials, are excellent in chemical and physical properties, so that various types of containers such as bottles, films, sheets, fibers, etc. Widely used in applications.

  On the other hand, the polyester resin is produced by, for example, an esterification reaction, a melt polycondensation reaction, and, if necessary, a solid-phase polycondensation reaction particularly for containers. As the polycondensation catalyst, antimony compounds or germanium compounds are mostly used on an industrial scale. However, a polyester resin using an antimony compound as a catalyst has a characteristic dullness, safety and hygiene based on toxicity pointed out in the antimony compound, consideration for the environment, etc., and a germanium compound as a catalyst. The polyethylene terephthalate resin is suitable in terms of transparency and safety and hygiene, but the germanium compound itself is extremely expensive and the economic disadvantage cannot be avoided. Appearance is strongly desired.

  For this reason, a number of compounds have been proposed as catalysts that can replace antimony compounds and germanium compounds. Among them, titanium compounds are inexpensive and have various problems because they have no problems in health and safety. Yes. However, a polyester resin using a titanium compound as a catalyst has a peculiar yellowish tint and is inferior in thermal stability. For example, a large amount of acetaldehyde derived from a decomposition reaction is produced as a byproduct during polycondensation and melt molding. Various proposals have been made for improving the color tone, thermal stability, etc., and reducing the acetaldehyde content.

  For example, Patent Document 1 proposes to use a titanium compound, an alkali metal or alkaline earth metal compound, and a phosphorus compound in a specific limited amount ratio. However, according to the study of the present inventors, the catalyst system described in the patent document can obtain a polyester resin having good color tone by melt polycondensation, but the solid-phase polycondensation rate is slow, so that the desired intrinsic viscosity is obtained. It takes a long time to obtain a resin and the color tone deteriorates accordingly, or a relatively large amount of titanium compound is required, or the color tone deteriorates, or cyclic trimer during solid phase polycondensation reaction. The reduction rate of oligomers such as bodies is slow, and as a result, especially when molding heat-resistant bottles and the like, the blow mold heated for heat setting is contaminated or the transparency of molded bodies such as bottles is reduced. It became clear that there was a problem.

  Patent Document 2 proposes that a titanium compound, a calcium compound and / or a magnesium compound as a co-catalyst, and a phosphorus compound are used in a specific quantitative ratio. However, according to the study by the present inventors, the polyester resin obtained by this method has a poor color tone, a slow solid-phase polycondensation rate, a large amount of cyclic trimer, and poor transparency of molded products such as bottles. Turned out to be.

In addition, paying attention to the above-mentioned disadvantages of the polyester resin using a titanium compound as a catalyst due to the content of the terminal carboxyl group in the resin, in order to reduce the amount of the terminal carboxyl group, lowering the polycondensation temperature, Methods such as increasing the proportion of ethylene glycol as a diol component in the raw material are known. However, the former method causes a decrease in productivity, and the latter method produces an ether compound such as diethylene glycol as a by-product. , Both lowering the softening point of the resin from which they are obtained and worsening the thermal stability, both of which can reduce the amount of terminal carboxyl groups, but at the same time a new problem occurs, The problem could not be solved basically.

  In Patent Document 3, it is possible to reduce the amount of terminal carboxyl groups while suppressing the by-production of ether compounds such as diethylene glycol, so that it has excellent thermal stability, excellent color tone, and solid-state weight. For the purpose of obtaining a polyester resin capable of reducing by-products such as oligomers and cyclic trimers by condensation, the esterification rate is 75 from the esterification step or transesterification step to the melt polycondensation step. % Addition of ethylene glycol in an amount of 4 to 40% by weight of the theoretical yield of the polyester resin with respect to the low molecular weight reaction product having a number average degree of polymerization of 3.0 to 10.0. Is disclosed. However, according to the study by the present inventors, in the method described in the patent document, the obtained polyester resin surely reduces the amount of terminal carboxyl groups and reduces by-product formation of oligomers in solid phase polycondensation. However, it has been found that the solid-phase polycondensation rate is decreased to suppress an increase in intrinsic viscosity and leave room for improvement in terms of thermal stability.

JP 2002-179781 A. Japanese Patent Application Laid-Open No. 7-292087. Japanese Patent Application Laid-Open No. 2002-47340.

  The present invention has been made in view of the above-mentioned prior art, and has been made for the purpose of providing a solution to the above-mentioned problems. Therefore, the present invention is a polyester resin polycondensed in the presence of a titanium compound, A polyester resin having a reduced amount of carboxyl groups and capable of reducing by-products such as oligomers and cyclic trimers by solid phase polycondensation, and having good physical properties such as color tone and transparency, and its An object of the present invention is to provide a method for producing a polyester resin at a high solid phase polycondensation rate.

The present invention has been made to achieve the above object, that is, the present invention performs an esterification reaction between a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol. Then, polycondensation in the presence of (1) a compound of at least one element selected from the group consisting of Group 4A titanium group elements of the periodic table, (2) a calcium compound, and (3) a phosphorus compound. The content as a titanium group atom of Group 4A of the periodic table derived from the compound of (1) is T (mol / ton of resin), and the content as a calcium atom derived from the compound of (2) is C (Mole / resin ton) and P (mole / resin ton) as the phosphorus atom content derived from the compound of (3), T, C, and P are represented by the following formulas (I) to (V): satisfied, the amount of terminal carboxyl groups of 40 equivalents / resin ton or less To the polyester resin, the a gist is.

  In addition, the present invention provides a group consisting of (1) a titanium group element of Group 4A of the periodic table through an esterification reaction between a dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol. In the polycondensation in the presence of at least one elemental compound selected from (2) a calcium compound and (3) a phosphorus compound, the compounds (1), (2) and (3) The amount added to the reaction system is the content of titanium group atoms in Group 4A of the periodic table derived from the compound (1) per ton of the obtained polyester resin, T (mol / ton of resin), (2) When the content as calcium atom derived from the compound of C is C (mol / ton of resin) and the content as phosphorus atom derived from the compound of (3) is P (mol / ton of resin), T, C , And P are amounts satisfying the following formulas (I) to (V), By adding adding ethylene glycol to the esterification reaction product, a method of manufacturing the polyester resin amount of terminal carboxyl group to produce a 40 equivalent / resin ton of the polyester resin, and the gist.

(I) 0.020 ≦ T ≦ 0.200
(II) 0.075 ≦ C ≦ 0.800
(III) 0.020 ≦ P ≦ 0.600
(IV) 0.80 ≦ C / P ≦ 4.00
(V) 1.00 ≦ C / T ≦ 20.00

  According to the present invention, it is a polyester resin polycondensed in the presence of a titanium compound, the amount of terminal carboxyl groups is suppressed, and byproducts such as oligomers and cyclic trimers due to solid phase polycondensation are reduced. It is possible to provide a polyester resin having good physical properties such as color tone and transparency, and a method for producing the polyester resin at a high solid-phase polycondensation rate.

The polyester resin of the present invention is obtained by polycondensing a dicarboxylic acid component having terephthalic acid as a main component and a diol component having ethylene glycol as a main component through an esterification reaction. Is 97.0 mol% or more with respect to the total dicarboxylic acid component, more preferably 99.0 mol% or more, and the content of ethylene glycol units is 97.0 mol% or more with respect to the total diol component, A polycondensate occupying 97.5 mol% or more is preferred. If the content of the terephthalic acid unit and the content of the ethylene glycol unit are less than the above ranges, the orientational crystallization of the molecular chain due to stretching when molding into a bottle or the like is insufficient, and the mechanical strength as a molded article such as a bottle. , Heat resistance, aroma retention, gas barrier properties and the like tend to be insufficient.

  Here, as dicarboxylic acid components other than terephthalic acid, for example, phthalic acid, isophthalic acid, dibromoisophthalic acid, sodium sulfoisophthalate, phenylenedioxydicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4,4 Aromatic dicarboxylic acids such as' -diphenyl ether dicarboxylic acid, 4,4'-diphenyl ketone dicarboxylic acid, 4,4'-diphenoxyethane dicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, 2,6-naphthalenedicarboxylic acid , Cycloaliphatic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid, and succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecadicarboxylic acid, dodecadicarboxylic acid, etc. Aliphatic dicarboxylic acids, etc. . Of these, isophthalic acid is preferred in the present invention.

  In addition, diol components other than ethylene glycol include diethylene glycol, and the content of the diethylene glycol unit is 3.0 mol based on the total diol component of the resulting polyester resin, including by-products in the reaction system. % Or less, more preferably 2.5 mol% or less, and particularly preferably 2.0 mol% or less. If the content of the diethylene glycol unit exceeds the above range, the heat resistance, aroma retention, gas barrier properties, stress crack resistance when the resulting resin is made into a molded article such as a bottle may be reduced, or the acetaldehyde content may be reduced. It tends to cause problems such as difficulty.

Examples of other diol components include trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, neopentyl glycol, 2-ethyl-2-butyl-1,3. -Aliphatic diols such as propanediol, polyethylene glycol, polytetramethylene ether glycol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol, 2, Cycloaliphatic diols such as 5-norbornane dimethylol, and xylylene glycol, 4,4′-dihydroxybiphenyl, 2,2-bis (4′-hydroxyphenyl) propane, 2,2-bis (4′-β) Aromatic diols such as hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfonic acid, and ethylene of 2,2-bis (4′-hydroxyphenyl) propane Examples thereof include an oxide adduct or a propylene oxide adduct.

  Furthermore, as copolymerization components, for example, hydroxycarboxylic acids and alkoxycarboxylic acids such as glycolic acid, p-hydroxybenzoic acid, p-β-hydroxyethoxybenzoic acid, and stearyl alcohol, heneicosanol, octacosanol, benzyl alcohol, stearic acid Monofunctional components such as behenic acid, benzoic acid, t-butylbenzoic acid, benzoylbenzoic acid, tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetetracarboxylic acid, gallic acid, trimethylolethane, trimethylol Trifunctional or more polyfunctional components such as methylolpropane, glycerol, pentaerythritol, sugar ester, and the like may be used.

  The polyester resin of the present invention undergoes an esterification reaction between the dicarboxylic acid component containing terephthalic acid as a main component and the diol component containing ethylene glycol as a main component, and (1) a titanium group element of Group 4A of the periodic table Obtained by polycondensation in the presence of a compound of at least one element selected from the group consisting of: (2) a calcium compound, and (3) a phosphorus compound.

  Here, (1) As a compound of titanium group element of Group 4A of the periodic table, that is, titanium, zirconium, and hafnium, a titanium compound is preferable. As the titanium compound, for example, tetra- n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, titanium acetate, titanium oxalate, potassium titanium oxalate, sodium titanium oxalate, titanic acid Potassium, sodium titanate, titanium chloride, titanium chloride-aluminum chloride mixture and the like, among them, titanium alkoxides such as tetra-n-propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, titanium oxalate Preferred is potassium potassium oxalate.

  Specific examples of the (2) calcium compound include calcium oxide, calcium hydroxide, calcium phosphate, calcium acetate, calcium carbonate, and the like, among which calcium acetate is preferable.

  (3) Specific examples of phosphorus compounds include orthophosphoric acid, polyphosphoric acid, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate. , Trivalent (triethylene glycol) phosphate, methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, monobutyl phosphate, dibutyl phosphate, dioctyl phosphate, pentavalent phosphorus such as phosphate ester such as triethylene glycol acid phosphate Compounds, and phosphorous acid, hypophosphorous acid, and trimethyl phosphite, diethyl phosphite, triethyl phosphite, trisdodecyl phosphite, Triphosphorus esters such as trisnonyl decyl phosphite, ethyl diethyl phosphonoacetate, triphenyl phosphite, etc., and trivalent phosphorus compounds such as metal salts such as lithium, sodium, potassium, etc. From the viewpoint of properties, a phosphoric ester of a pentavalent phosphorus compound is preferable, and trimethyl phosphate and ethyl acid phosphate are particularly preferable.

  The polyester resin of the present invention comprises (1) a compound of at least one element selected from the group consisting of titanium group elements of Group 4A of the periodic table, (2) calcium compound, and (3) phosphorus compound, A polyester resin obtained by polycondensation in the presence of the compound (1), wherein the content as a titanium group atom of Group 4A of the periodic table derived from the compound (1) is T (mol / ton of resin), (2 ) Where the content as a calcium atom derived from the compound of C) is C (mol / ton of resin), and the content as a phosphorus atom derived from the compound of (3) is P (mol / ton of resin), T, It is preferable that C and P satisfy the following formulas (I) to (V).

(I) 0.020 ≦ T ≦ 0.200
(II) 0.075 ≦ C ≦ 0.800
(III) 0.020 ≦ P ≦ 0.600
(IV) 0.80 ≦ C / P ≦ 4.00
(V) 1.00 ≦ C / T ≦ 20.00

  In the present invention, the content as a titanium group atom of group 4A of the periodic table derived from (1) a compound of at least one element selected from the group consisting of group 4A titanium groups of the periodic table T preferably satisfies the following formula (I), more preferably satisfies the following formula (I ′), and particularly preferably satisfies the following formula (I ″). The content T as a titanium group atom of group 4A of the periodic table derived from the compound of (1) at least one element selected from the group consisting of group 4A titanium group elements of the periodic table is represented by the following formula: If the value is less than the left side value, the polycondensation tends to decrease. On the other hand, if the right side value is exceeded, the color tone of the polyester resin becomes yellowish, and the acetaldehyde content in the molded product tends to be high. It becomes.

(I) 0.020 ≦ T ≦ 0.200
(I ′) 0.060 ≦ T ≦ 0.100
(I '') 0.070 ≦ T ≦ 0.090

  In the present invention, the content C as a calcium atom derived from the (2) calcium compound preferably satisfies the following formula (II), but more preferably satisfies the following formula (II ′). It is particularly preferable that the following formula (II ″) is satisfied. When the content C as a calcium atom derived from the calcium compound (2) is less than the left side value of the following formula, the color tone as a polyester resin is deteriorated, and polycondensation property, particularly solid phase polycondensation property is obtained. On the other hand, if the right-hand side value is exceeded, the polycondensation property, particularly the melt polycondensation property, tends to decrease.

(II) 0.075 ≦ C ≦ 0.800
(II ′) 0.150 ≦ C ≦ 0.350
(II '') 0.200 ≦ C ≦ 0.300

  In the present invention, the content P as a phosphorus atom derived from the (3) phosphorus compound preferably satisfies the following formula (III), but more preferably satisfies the following formula (III ′). It is particularly preferable that the following formula (III ″) is satisfied. When the content P as a phosphorus atom derived from the (3) phosphorus compound is less than the left side value of the following formula, the acetaldehyde content in the polyester resin tends to be large, while on the other hand, when the right side value is exceeded, The polycondensation property tends to decrease.

(III) 0.020 ≦ P ≦ 0.600
(III ') 0.050 ≦ P ≦ 0.300
(III '') 0.090 ≦ P ≦ 0.250

In the present invention, the content T as a titanium group atom of Group 4A of the periodic table derived from the compound (1), the content C as a calcium atom derived from the compound (2), and (3) It is preferable that the content P as a phosphorus atom derived from each of the compounds satisfies the formulas (I) to (III) and C / P satisfies the following formula (IV). It is more preferable that IV ′) is satisfied, and it is particularly preferable that the following formula (IV ″) is satisfied. Further, C / T preferably satisfies the following formula (V), more preferably satisfies the following formula (V ′), and particularly preferably satisfies the following formula (V ″). When C / P and C / T are less than the left-hand side value of the following formula, the color tone of the polyester resin becomes yellowish, and polycondensability, particularly solid-phase polycondensation, tends to decrease. On the other hand, even if the value on the right side is exceeded, the polycondensability tends to decrease or the color tone tends to deteriorate.

(IV) 0.80 ≦ C / P ≦ 4.00
(IV ′) 1.00 ≦ C / P ≦ 2.00
(IV ″) 1.10 ≦ C / P ≦ 1.50
(V) 1.00 ≦ C / T ≦ 20.00
(V ') 2.00 ≦ C / T ≦ 5.00
(V ″) 2.40 ≦ C / T ≦ 4.00

In addition, the polyester resin of the present invention comprises (1) a compound of at least one element selected from the group consisting of titanium group elements of Group 4A of the periodic table, (2) calcium compound, and (3) phosphorus (4) polycondensation in the presence of at least one compound selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium. It is preferable that it is obtained by this.

  Here, (4) at least one compound selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium includes oxide, hydroxide, alkoxide, fatty acid of each element Salts, carbonates, phosphates, nitrates, halides, complex compounds, and the like. Specific examples include magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, magnesium carbonate, aluminum acetate, aluminum nitrate, Aluminum acetylacetonate, manganese dioxide, manganese hydroxide, manganese acetate, iron acetate, iron phosphate, iron nitrate, iron acetylacetonate, cobalt acetate, cobalt nitrate, cobalt acetylacetonate, copper formate, copper acetate, copper nitrate, oxidation Zinc, zinc acetate, zinc carbonate, zinc nitrate, nitric acid Among them, gallium and the like can be mentioned. Among them, a metal element having tetracoordination and pentacoordination is preferable, and magnesium acetate and zinc acetate are particularly preferable.

Further, when the content of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium atoms derived from the compound (4) is M (mol / ton of resin), M is represented by the following formula ( It is preferable to satisfy VI). When the content M as magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium atoms derived from the compound (4) is less than the left-side value of the following formula, polycondensation properties, The polycondensation property tends to decrease, and the cyclic trimer content tends to be high. On the other hand, if the right side value is exceeded, the color tone of the polyester resin tends to deteriorate or the thermal stability tends to be poor.
(VI) 0.004 ≦ M ≦ 0.800

As will be described later, the polyester resin of the present invention has a terminal carboxyl group amount of 40 equivalents / ton or less of resin, but is contained as a titanium group atom of Group 4A of the periodic table derived from the compound of (1). The amount T, the content C as a calcium atom derived from the compound of (2), and the content P as a phosphorus atom derived from each compound of (3) satisfy the above formulas (I) to (V). Thus, as the amount of the terminal carboxyl group is further reduced, the melt polycondensation property is particularly improved, and the cyclic trimer content is further reduced. Further, when the content M as magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium atoms derived from the compound of (4) satisfies the formula (VI), the amount of terminal carboxyl groups In particular, as the amount of the polymer is further reduced, the solid-phase polycondensation property is improved, and the cyclic trimer content is further reduced.

  The polyester resin of the present invention is obtained by subjecting a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing ethylene glycol as a main component to an esterification reaction, from (1) the titanium group element of Group 4A of the periodic table. In the presence of at least one elemental compound selected from the group consisting of (2) calcium compound and (3) phosphorus compound, preferably (4) magnesium, aluminum, manganese, iron, It is obtained by polycondensation in the presence of at least one compound selected from the group consisting of cobalt, copper, zinc, and gallium. In the polycondensation, the above (1), (2 ) And (3), or further, the amount of addition of the compound (4) to the reaction system is the amount of the group 4A of the periodic table derived from the compound (1) per ton of the obtained polyester resin. Chita The content as a group atom is T (mole / resin ton), the content as a calcium atom derived from the compound (2) is C (mole / resin ton), and the phosphorus atom is derived from the compound (3). The content is P (mol / ton of resin), and the content of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium atoms derived from the compound of (4) is M (mol / ton of resin). The amount satisfying the above formulas (I) to (V), preferably the amount satisfying the above formula (VI), and by adding ethylene glycol to the esterification reaction product. Can do.

  In addition, as the manufacturing method, it is based on the conventional manufacturing method of a polyester resin fundamentally. That is, as a raw material slurry prepared by mixing a dicarboxylic acid component containing terephthalic acid as a main component and a diol component containing ethylene glycol as a main component together with a copolymer component used as necessary, an ester, The esterification reaction tank is charged with an esterification reaction under normal pressure to under pressure and under heating, and the resulting polyester low molecular weight product as the esterification reaction product is transferred to the polycondensation tank. In the presence of each of the above compounds, melt polycondensation is carried out under heating from normal pressure to gradually reduced pressure.

Here, the raw slurry is prepared by combining a dicarboxylic acid component having a terephthalic acid as a main component, a diol component having ethylene glycol as a main component, and a copolymer component used as necessary, with respect to the dicarboxylic acid component. The molar ratio is preferably in the range of 1.02 to 2.0, more preferably 1.03 to 1.7.

  In addition, the esterification reaction can be carried out by using a single esterification reaction tank or a multistage reaction apparatus in which a plurality of esterification reaction tanks are connected in series under reflux of ethylene glycol and excess water and water produced by the reaction. While removing ethylene glycol from the system, the esterification rate of the resulting low molecular weight polyester (ratio of the esterified by reacting with the diol component out of the total carboxyl groups of the raw dicarboxylic acid component) is preferably 90% Above, more preferably 95% or more, the number average degree of polymerization is preferably 3.0 to 10.0, more preferably 4.0 to 8.0 in the continuous polymerization system, batch polymerization system Is preferably 5.0 to 9.0, particularly preferably 5.0 to 7.0 in the continuous polymerization system, and 6.0 to 8.0 in the batch polymerization system.When the esterification rate and the number average degree of polymerization are within this range, ethylene glycol, which will be described later, can be added under relatively low temperature and low pressure conditions, and both terminal carboxyl groups and diethylene glycol by-product amounts can be reduced. It can be reduced.

  As reaction conditions in the esterification reaction, in the case of a single esterification reaction tank, the temperature is usually about 240 to 280 ° C., and the relative pressure to atmospheric pressure is usually about 0 to 400 kPa (0 to 4 kg / cm 2 G), The reaction time is about 1 to 10 hours under stirring. In the case of a plurality of esterification reaction tanks, the reaction temperature in the first stage esterification reaction tank is usually 240 to 270 ° C., preferably 245 to 265 ° C., and the relative pressure to atmospheric pressure is usually 5 to 300 kPa. (0.05 to 3 kg / cm 2 G), preferably 10 to 200 kPa (0.1 to 2 kg / cm 2 G), and the reaction temperature in the final stage is usually 250 to 280 ° C., preferably 255 to 275 ° C., atmospheric pressure The relative pressure is usually 0 to 150 kPa (0 to 1.5 kg / cm @ 2 G), preferably 0 to 130 kPa (0 to 1.3 kg / cm @ 2 G).

In the esterification reaction, for example, tertiary amines such as triethylamine, tri-n-butylamine, and benzyldimethylamine, hydroxides such as tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, and trimethylbenzylammonium hydroxide are used. By adding a small amount of a basic compound such as quaternary ammonium, lithium carbonate, sodium carbonate, potassium carbonate, or sodium acetate, by-production of diethylene glycol from ethylene glycol can be suppressed.

  Subsequently, the obtained esterification reaction product is transferred to one or a plurality of polycondensation tanks and subjected to a melt polycondensation reaction under heating under reduced pressure as a gradual reduced pressure from normal pressure.

  The method for producing a polyester resin of the present invention requires that ethylene glycol be additionally added to the esterification reaction product, but the esterification rate of the esterification reaction product when ethylene glycol is additionally added. Is preferably 90% or more, more preferably 95% or more, and particularly preferably 97% or more. If the esterification rate is less than the above range, it takes a long time for the esterification reaction with the additionally added ethylene glycol, so that ethylene glycol is dehydrated and condensed by acid catalysis of the terminal carboxyl group, and diethylene glycol tends to be generated.

  Further, the number average polymerization degree of the esterification reaction product when ethylene glycol is additionally added is preferably 3.0 to 10.0, and in the continuous polymerization system, it is 4.0 to 8.0. Is more preferably 5.0 to 7.0, more preferably 5.0 to 9.0 in the batch polymerization method, and 6.0 to 8.0. Is particularly preferred. If the number average degree of polymerization is less than the above range, the reaction product transferred to the polycondensation tank and placed under reduced pressure is likely to sublimate and volatilize, causing troubles such as clogging of the distillation system, and time for polycondensation. However, when the amount exceeds the above range, the number of all terminals decreases and the proportion of carboxyl groups in the total number of terminals increases. The additional addition tends not to reduce the terminal carboxyl group.

  Further, in the present invention, the additional addition of ethylene glycol is performed on the reaction product under pressure of a temperature of 250 ° C. or more and less than 265 ° C. and a pressure of 1.0 × 10 5 Pa relative to normal pressure to atmospheric pressure. The temperature is more preferably not lower than 255 ° C. and lower than 265 ° C., and the pressure is more preferably under a pressure of 0.5 × 10 5 Pa relative to normal pressure to atmospheric pressure, and normal pressure to high It is particularly preferable that the pressure is a relative pressure of 0.3 × 10 5 Pa relative to the atmospheric pressure.

  If the temperature is lower than the above range, the addition of ethylene glycol may cool the inside of the system and the reaction product may solidify.On the other hand, if the temperature exceeds the above range, evaporation and volatilization of the additional ethylene glycol will be intense. Further, ethylene glycol tends to be dehydrated and condensed due to the acid catalysis of the terminal carboxyl group, and diethylene glycol tends to be easily formed. In addition, when the pressure is less than the above range, the additional added ethylene glycol is severely evaporated and volatilized, whereas when it exceeds the above range, ethylene glycol tends to be dehydrated and condensed due to the acid catalysis of the terminal carboxyl group, and diethylene glycol tends to be generated. Become.

  In the method for producing a polyester resin of the present invention, the additional addition of ethylene glycol is from the esterification reaction stage to the melt polycondensation reaction stage, and the esterification reaction product is the esterification rate, the number The average degree of polymerization is satisfied, and the reaction is carried out at one or a plurality of places under the temperature and pressure ranges, but before the pressure reduction is applied from the esterification reaction stage to the melt polycondensation reaction stage. The esterification reaction product in any of the above is preferably applied to the reaction product under normal pressure after being subjected to the esterification reaction stage and before being subjected to reduced pressure in the melt polycondensation reaction stage. It is particularly preferable to make it.

  Furthermore, in the present invention, the amount of ethylene glycol to be added is preferably 4 to 40% by weight of the theoretical yield of the polyester resin. When the additional addition of ethylene glycol is made at the stage of the esterification reaction, 4 is added. More preferably, it is made into -20 weight%, and it is especially preferable to set it as 4-15 weight%. If the additional addition amount is less than the above range, the terminal carboxyl group tends to be insufficiently reduced. On the other hand, if it exceeds the above range, the polymerization degree tends to decrease due to cooling solidification or depolymerization in the system.

  In the present invention, the addition form of ethylene glycol to be added may be pure ethylene glycol, a solution of a copolymer component, a solution of a catalyst, or other additives.

  The melt polycondensation is performed by connecting a single polycondensation tank or a plurality of polycondensation tanks in series, for example, a fully mixed reactor in which the first stage includes a stirring blade, the second stage, and The third stage is carried out by distilling the produced ethylene glycol out of the system under reduced pressure using a multistage reactor comprising a horizontal plug flow reactor equipped with a stirring blade.

  As reaction conditions in the melt polycondensation, in the case of a single polycondensation tank, the temperature is usually about 250 to 290 ° C. The pressure is gradually reduced from normal pressure, and finally the absolute pressure is usually 1.3 to 0.013 kPa. (10 to 0.1 Torr) and a reaction time of about 1 to 20 hours with stirring. In the case of a plurality of polycondensation tanks, the reaction temperature in the first stage polycondensation tank is usually 250 to 290 ° C., preferably 260 to 280 ° C., and the absolute pressure is usually 65 to 1.3 kPa (500 to 10 Torr), preferably 26 to 2 kPa (200 to 15 Torr), the reaction temperature in the final stage is usually 265 to 300 ° C., preferably 270 to 295 ° C., and the absolute pressure is usually 1.3 to 0.013 kPa (10 to 10 Torr). 0.1 Torr), preferably 0.65 to 0.065 kPa (5 to 0.5 Torr). As reaction conditions in the intermediate stage, those intermediate conditions are selected. For example, in a three-stage reactor, the reaction temperature in the second stage is usually 265 to 295 ° C., preferably 270 to 285 ° C., and the absolute pressure is Usually, it is 6.5 to 0.13 kPa (50 to 1 Torr), preferably 4 to 0.26 kPa (30 to 2 Torr).

  In addition, (1) a compound of at least one element selected from the group consisting of titanium group elements of Group 1A of the periodic table, a calcium compound of (2), a phosphorus compound of (3), and ( 4) Addition of at least one compound selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium to the reaction system may be any stage in the esterification reaction from the raw slurry preparation. Or in the initial stage of the melt polycondensation reaction, the order of their addition is the compound of (3), the compound of (2), then the compound of (1), When the compound (4) is used, the compound (3), the compound (4), the compound (2), and then the compound (1) are preferred.

  The thermal stability of the resin is improved by making the addition timing and addition order of the compounds (1), (2), (3), and (4) to the reaction system as described above. In addition, the color tone of the solid phase polycondensation resin tends to be improved, and the by-product of diethylene glycol in the reaction system, which causes by-products such as acetaldehyde during melt molding, is also suppressed. The effect of improving the phase polycondensability can be effectively expressed.

  The addition of the compounds (1), (2), (3), and (4) to the reaction system is preferably carried out as a solution of alcohol such as ethylene glycol or water. In the case of using the titanium compound as the compound of 1), the ethylene glycol solution has a titanium atom concentration of 0.01 to 0.3% by weight and a water concentration of 0.1 to 1% by weight. This is preferable from the viewpoint of improving the dispersibility of the titanium compound in the system and the resulting melt polycondensation property and solid phase polycondensation property.

The polyester resin obtained by the melt polycondensation has an intrinsic viscosity ([η1]) as a value measured at 30 ° C. using phenol / tetrachloroethane (weight ratio 1/1) as a solvent at 0.35 to 0.75 dl / g is preferable, and 0.50 to 0.65 dl / g is more preferable. If the intrinsic viscosity ([η1]) is less than the above range, the extractability described later from the polycondensation tank tends to be poor, whereas if it exceeds the above range, the amount of cyclic trimer in the resulting resin is reduced. It becomes a difficult tendency.

  The resin obtained by the melt polycondensation is usually extracted in a strand form from an outlet provided at the bottom of the polycondensation tank, and is cooled with water or after water cooling, and then cut with a cutter to form pellets, chips, etc. Further, the granular material after the melt polycondensation is usually 100 kPa (1 kg / cm @ 2 G) or less as a relative pressure with respect to the atmospheric pressure in an inert gas atmosphere such as nitrogen, carbon dioxide and argon. The pressure is usually about 5 to 30 hours under a pressure of 20 kPa (0.2 kg / cm @ 2 G) or less, or the absolute pressure is usually 6.5 to 0.013 kPa (50 to 0.1 Torr), preferably 1. It is usually heated at a temperature of 190 to 230 ° C, preferably 195 to 225 ° C under a reduced pressure of 3 to 0.065 kPa (10 to 0.5 Torr) for about 1 to 20 hours. It is preferable to carry out solid phase polycondensation. By this solid phase polycondensation, the degree of polymerization can be further increased, and the content of the cyclic trimer and the like can be reduced.

  At that time, prior to solid phase polycondensation, it is usually 120 to 200 ° C., preferably 130 to 190 ° C. for 1 minute to 4 in an inert gas atmosphere, or in a water vapor atmosphere or a water vapor-containing inert gas atmosphere. It is preferable to crystallize the resin granule surface by heating for about an hour. In particular, it is preferable to perform the reaction under a water vapor atmosphere because the crystallization rate of the resin granules can be improved or the acetaldehyde content of the resulting polyester resin can be further reduced.

  Furthermore, the resin obtained by melt polycondensation or solid phase polycondensation as described above is usually treated with water treated for 10 minutes or more in warm water of 40 ° C. or higher, or in water vapor or water vapor-containing gas of 60 ° C. or higher. Treatment with water vapor treatment for 30 minutes or more, treatment with an organic solvent, treatment with various aqueous acids, organic acids, phosphorous acid, phosphoric acid, phosphoric acid esters, or other acidic aqueous solutions or organic solvent solutions, or The catalyst used for polycondensation can also be deactivated by performing treatment with an alkaline aqueous solution or organic solvent solution of a Group 1A metal, a Group 2A metal, an amine or the like.

  The polyester resin obtained by the solid phase polycondensation has an intrinsic viscosity ([η2]) of 0.70 to 0.90 dl as a value measured at 30 ° C. using phenol / tetrachloroethane (weight ratio 1/1) as a solvent. / G, preferably 0.72 to 0.80 dl / g. If the intrinsic viscosity ([η2]) is less than the above range, mechanical strength as a molded article such as a bottle tends to be insufficient. On the other hand, if it exceeds the above range, by-product such as acetaldehyde during melt molding may be suppressed. It becomes a difficult tendency. Further, the difference ([η2]-[η1]) between the intrinsic viscosity ([η2]) of the obtained solid phase polycondensation resin and the intrinsic viscosity ([η1]) of the melt polycondensation resin is expressed as the solid phase polycondensation time. The solid phase polycondensation rate as a value divided by (T) is preferably 0.008 to 0.030 dl / g / hr, more preferably 0.015 to 0.030 dl / g / hr. .

  The polyester resin of the present invention obtained by the above production method has a terminal carboxyl group amount of 40 equivalents / ton of resin or less, preferably 20 equivalents / ton of resin or less, and preferably 10 equivalents / ton of resin or less. Further preferred.

  The polyester resin of the present invention has a cyclic trimer content of 0.5% from the viewpoint of preventing mold contamination during molding of bottles and the like, and imparting transparency and appearance to the molded body. % Or less is preferable, and 0.45% by weight or less is more preferable.

  In addition, the polyester resin of the present invention preferably has an acetaldehyde content of 5.0 ppm or less from the viewpoint of suppressing adverse effects on the flavor, aroma and the like of the contents as a molded article such as a bottle. More preferably, it is 0 ppm or less. Further, the acetaldehyde content in a molded article injection-molded at 280 ° C. is preferably 23 ppm or less, and more preferably 20 ppm or less.

  The polyester resin of the present invention preferably has a haze of 10.0% or less, more preferably 5.0% or less, in a molded plate having a thickness of 5 mm which is injection-molded at 280 ° C.

  In addition, the polyester resin of the present invention has a color coordinate b of Hunter's color difference formula according to Lab color system described in Reference 1 of JIS Z8730 from the aspect of suppressing the yellowish color tone as a molded article such as a bottle. The value is preferably 4.0 or less, and more preferably 3.0 or less. The lightness index L value is preferably 85 or more, and more preferably 88 or more.

  In order to make the color coordinate b value within the above range, a so-called organic toning agent may be added. Examples of the organic toning agent include Solvent Blue 104, Solvent Red 135, Solvent Violet. 36, Pigment Blue 29, 15: 1, 15: 3, Pigment Red 187, 263, Pigment Violet 19, and the like, and the addition amount thereof suppresses a decrease in the lightness index L value. Therefore, it is preferably 3.0 ppm or less, and more preferably 1.0 ppm or less. The organic toning agent may be added at any time from the polyester resin production stage to the molding stage.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded.

Example 1
A slurry of 43 parts by weight of terephthalic acid and 19 parts by weight of ethylene glycol was charged in an esterification reaction vessel in which 60 parts by weight of an ethylene terephthalate oligomer having an average degree of polymerization of 6 was previously charged and maintained at a temperature of 250 ° C. and a pressure of 1.2 × 10 5 Pa. Is supplied over 4 hours to carry out the esterification reaction. After completion of the supply, the esterification reaction is carried out over an additional hour, and then 60 parts by weight of the resulting esterification reaction product is transferred to a polycondensation tank. From the piping, ethyl acid phosphate is added as an ethylene glycol solution in such an amount that the content P as a phosphorus atom per ton of the obtained polyester resin is 0.194 mol / ton, and after 5 minutes, calcium acetate -Content C as a calcium atom per ton of the obtained polyester resin as an ethylene glycol solution of dihydrate Is added in an amount of 0.167 mol / ton, and after 5 minutes, tetra-n-butyl titanate is added as an ethylene glycol solution, and the content T of titanium atoms per ton of the resulting polyester resin is 0.00. After adding at an amount of 084 mol / ton, 10 parts by weight of ethylene glycol was additionally added. The esterification rate of the esterification reaction product at that time was 95%, and the number average degree of polymerization was 7.7. The total amount of ethylene glycol added was 10% by weight of the theoretical yield of the resulting polyester resin, including the amount added as the solution. After 5 minutes from the end of the addition, the system was heated from 250 ° C. to 280 ° C. over 2 hours and 30 minutes, and the pressure was reduced from normal pressure to 4 × 10 2 Pa in 1 hour while maintaining the same pressure. After the melt polycondensation until the intrinsic viscosity ([η1]) of the resulting polyester resin is about 0.60 dl / g, the polyester resin is extracted in the form of a strand from the extraction port provided at the bottom of the polycondensation tank, and after cooling with water, chips By cutting into a shape, a melt polycondensed polyester resin chip was obtained.

Subsequently, the melt polycondensed polyester resin chip obtained above was crystallized by continuously supplying it into a stirring crystallization machine maintained at about 160 ° C. so that the residence time was 5 minutes, and an inert oven ( In ESPEC "IPHH-201 type"), after drying at 160 ° C for 2 hours under a nitrogen gas stream of 40 l / min, the intrinsic viscosity ([η2]) of the polyester resin obtained is 210 at 210 ° C. Solid phase polycondensation was performed by heating for 75 dl / g.

About the obtained solid phase polycondensation polyester resin, the content of diethylene glycol units is measured by the method shown below, and further, the content T (mol / ton of resin) as a titanium atom, and the content C (as a calcium atom) ( Mol / resin ton) and the content P (mol / ton of resin) as a phosphorus atom were measured, and from the results, C / P value and C / T value were calculated, and the results are shown in Table 1. .

<Content of diethylene glycol unit>
Using a pulverizer (William type “1029-A” manufactured by Yoshida Seisakusho), 5.00 g of a resin sample pulverized with a 1.5 mm hole eye plate, 50 ml of 4N KOH / methanol solution was added, and a reflux condenser was set. While stirring on a hot plate (surface temperature 200 ° C.) with a magnetic stirrer, the mixture is heated to reflux for 2 hours to be hydrolyzed. After allowing to cool, about 20 g of high-purity terephthalic acid was added, and the slurry was sufficiently shaken to neutralize to a pH of 9 or less, filtered using an 11G-4 glass filter, and then washed twice with 2 ml of methanol. The filtrate and washing solution are combined, and 1 μl thereof is injected into a gas chromatography (“GC-14APF” manufactured by Shimadzu Corporation) with a microsyringe, and diethylene glycol for all diol components from the peak area of each diol unit. The content of the unit was calculated according to the following formula.
Content of diethylene glycol unit (mol%) = (ACO × CfCO) / [Σ (A × Cf)] × 100
[Where ACO is the area (μV · sec) of the diethylene glycol unit, CfCO is the correction coefficient of the diol unit, A is the area (μV · sec) of each diol unit, and Cf is the correction coefficient of each diol unit. ]
In addition, the use conditions of gas chromatography are as follows.
Column: “DB-WAX” (0.53 mm × 30 mm) manufactured by J & W
Set temperature: Column; 160-220 ° C
Vaporization chamber; 230 ° C
Detector: 230 ° C
Gas flow rate: Carrier (nitrogen); 5 ml / min
Hydrogen: 0.6kg / cm2
Air; 0.6kg / cm2
Detector: FID
Sensitivity: 10 2 MΩ

<Metal atom content>
A resin sample (5 g) was incinerated with hydrogen peroxide in the presence of sulfuric acid in a conventional manner, completely decomposed, and then made up to a constant volume of 50 ml with distilled water. Type | mold)), and converted into the molar amount in 1 ton of polyester resins.

Further, for the obtained melt polycondensation polyester resin and solid phase polycondensation polyester resin, the intrinsic viscosity [η1] of the melt polycondensation resin and the intrinsic viscosity [η2] of the solid phase polycondensation resin were measured by the following methods. Further, by dividing the intrinsic viscosity [η1] by the melt polycondensation time (T1), the melt polycondensation rate can be obtained, and the difference between the intrinsic viscosity ([η2]) and the intrinsic viscosity ([η1]) ([η2 ]-[Η1]) divided by the solid phase polycondensation time (T2), the solid phase polycondensation rate was calculated, and the results are shown in Table 1.

<Intrinsic viscosity [η1] ・ [η2]>
0.25 g of the freeze-pulverized resin sample is mixed with a mixed solvent of phenol / tetrachloroethane (weight ratio 1/1), the concentration (c) is 1.0 g / dl, and in the case of a melt polycondensation resin, 110 ° C. for 30 minutes. In the case of a solid phase polycondensation resin, after dissolving by holding at 120 ° C. for 30 minutes, the relative viscosity (η rel) with the stock solution is measured at 30 ° C. using an Ubbelohde type capillary viscosity tube. The ratio (ηsp / c) between the specific viscosity (ηsp) and the concentration (c) obtained from the viscosity (ηrel) -1 was determined, and the concentration (c) was similarly 0.5 g / dl, 0.2 g / dl,. The respective ratios (ηsp / c) were also obtained when 1 g / dl, and the ratio (ηsp / c) when the concentration (c) was extrapolated to 0 was calculated from these values as the intrinsic viscosity (dl / g). As sought.

The obtained solid phase polycondensation polyester resin was measured for the amount of terminal carboxyl groups by the method shown below, and the results are shown in Table 1.

<Amount of terminal carboxyl group>
After crushing the chip, it was dried at 140 ° C. for 15 minutes in a hot air dryer, and 0.1 g was accurately weighed out from a sample cooled to room temperature in a desiccator, and 3 ml of benzyl alcohol was added, The solution was dissolved at 195 ° C. for 3 minutes while blowing dry nitrogen gas, and then 5 ml of chloroform was gradually added and cooled to room temperature. One to two drops of phenol red indicator were added to this solution, and titrated with 0.1 N sodium hydroxide in benzyl alcohol with stirring while blowing dry nitrogen gas, and the procedure was terminated when the color changed from yellow to red. Further, as a blank, the same operation was performed without a polyester resin sample, and the acid value was calculated by the following formula.
Acid value (mol / ton) = (A−B) × 0.1 × f / W
[Where A is the amount of benzyl alcohol solution of 0.1N caustic soda required for titration (μl), B is the amount of benzyl alcohol solution of 0.1N caustic soda required for titration with blank (μl) , W is the amount (g) of the polyester resin sample, and f is the titer of the benzyl alcohol solution of 0.1N caustic soda. ]
In addition, the titer (f) of 0.1N caustic soda benzyl alcohol solution was obtained by taking 5 ml of methanol into a test tube, adding 1 to 2 drops of phenol red ethanol solution as an indicator, and adding 0.1N caustic soda benzyl alcohol. Titrate to the color change point with 0.4 ml of solution, then add 0.2 ml of 0.1N hydrochloric acid aqueous solution of known titer as a standard solution and add it again to the color change point with 0.1N sodium hydroxide in benzyl alcohol. Titration. (The above operation was performed while blowing dry nitrogen gas.) The titer (f) was calculated by the following equation.
Titer (f) = Titer of 0.1N hydrochloric acid aqueous solution × Sample volume of 0.1N hydrochloric acid aqueous solution (μl) / Titration volume of 0.1N sodium hydroxide in benzyl alcohol (μl)

  Further, with respect to the obtained solid phase polycondensation polyester resin, the cyclic trimer content and the acetaldehyde content were measured by the following methods, and the results are shown in Table 1.

<Cyclic trimer content>
10 g of a resin sample was dried in an inert oven (“IPHH-201 type” manufactured by ESPEC) for 2 hours at 160 ° C. under a nitrogen gas stream of 50 l / min, 4.0 mg was precisely weighed, and chloroform / hexa After dissolving in 2 ml of a mixed solvent of fluoroisopropanol (volume ratio 3/2), further diluted by adding 20 ml of chloroform, precipitated by adding 10 ml of methanol, and the filtrate obtained by subsequent filtration was evaporated to dryness. Thereafter, the product was dissolved in 25 ml of dimethylformamide, and the amount of cyclic trimer (cyclotriethylene terephthalate) in the solution was quantified by liquid chromatography (“LC-10A” manufactured by Shimadzu Corporation).

<Acetaldehyde content>
A resin sample (5.0 g) is precisely weighed, sealed in a 50 ml internal volume cylinder with 10 ml of pure water under a nitrogen seal, and heated and extracted at 160 ° C. for 2 hours. The amount of acetaldehyde in the extract is determined by isobutyl alcohol. Was quantified using gas chromatography (“GC-14A” manufactured by Shimadzu Corporation) as an internal standard.

  Further, with respect to the obtained solid phase polycondensation polyester resin, the color coordinate b value as a color tone was measured by the following method, and the results are shown in Table 1.

<Color tone>
A resin sample was filled in a cylindrical powder colorimetric cell having an inner diameter of 36 mm and a depth of 15 mm, and using a colorimetric color difference meter (“ND-300A” manufactured by Nippon Denshoku Industries Co., Ltd.), Reference 1 of JIS Z8730 The color coordinate b value of Hunter's color difference formula according to the Lab color system described in the above was obtained as a simple average value of values measured at four points by rotating the measurement cell by 90 degrees by the reflection method.

  Subsequently, the obtained solid-phase polycondensation polyester resin was dried in an inert oven (“IPHH-201 type” manufactured by ESPEC) for 4 hours at 160 ° C. in a nitrogen gas stream at 40 l / min, and then injection molded. Machine (“M-70AII-DM” manufactured by Meiki Seisakusho), cylinder temperature 280 ° C., back pressure 5 × 10 5 Pa, injection rate 40 cc / sec, holding pressure 35 × 10 5 Pa, mold temperature 25 ° C., molding cycle In about 75 seconds, a stepped molding plate having a shape shown in FIG. 1 and having a thickness of 50 mm in length and 100 mm in width and having a thickness of 6 steps from 6 mm to 3.5 mm in the horizontal direction is 0.5 mm. In FIG. 1, G is a gate part.) With respect to the obtained molded plate, the cyclic trimer content, the acetaldehyde content, and the haze were measured by the methods shown below, and the results are shown in Table 1. It was.

<Cyclic trimer content>
Measurement was performed in the same manner as described above using a sample cut into a 4 mm square from a tip portion (A portion in FIG. 1) having a thickness of 3.5 mm on the molded plate.
<Acetaldehyde content>
Measurement was performed in the same manner as described above using a sample cut into a 4 mm square from the rear end portion (B portion in FIG. 1) of the 3.5 mm thick portion of the molded plate.
<Haze>
About the thickness 5.0mm part (C part in FIG. 1) in a shaping | molding board, it measured using the haze meter ("NDH-300A" by Nippon Denshoku).

Examples 2-4
Ethyl acid phosphate, calcium acetate dihydrate, and tetra-n-butyl titanate as ethylene glycol solutions, respectively, content P as a phosphorus atom per ton of the resulting polyester resin, content C as a calcium atom A polyester resin was produced in the same manner as in Example 1 except that the T was added so that the content T as a titanium atom was the amount shown in Table 1, and evaluated in the same manner. It was shown in 1.

Example 5
Ethyl acid phosphate, magnesium acetate tetrahydrate, calcium acetate dihydrate, and tetra-n-butyl titanate are each made into an ethylene glycol solution in this order, sequentially at intervals of 5 minutes, to obtain a polyester resin 1 The content P as a phosphorus atom per ton, the content M as a magnesium atom, the content C as a calcium atom, and the content T as a titanium atom were added so as to have the amounts shown in Table 1, respectively. The polyester resin was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

Example 6
Ethyl acid phosphate, zinc acetate dihydrate, calcium acetate dihydrate, and tetra-n-butyl titanate are each made into an ethylene glycol solution in this order, sequentially at intervals of 5 minutes, to obtain a polyester resin 1 The content P as a phosphorus atom per ton, the content M as a zinc atom, the content C as a calcium atom, and the content T as a titanium atom were added so as to have the amounts shown in Table 1, respectively. The polyester resin was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

Example 7
After adding each ethylene glycol solution of ethyl acid phosphate, calcium acetate dihydrate, and tetra-n-butyl titanate, the same as in Example 1 except that no additional ethylene glycol was added. A polyester resin was produced and evaluated in the same manner, and the results are shown in Table 1.

Comparative Example 1
Ethyl acid phosphate, calcium acetate dihydrate, and tetra-n-butyl titanate as ethylene glycol solutions, respectively, content P as a phosphorus atom per ton of the resulting polyester resin, content C as a calcium atom In addition to the addition of ethylene glycol in addition to the addition of these ethylene glycol solutions, the content T as titanium atoms was added so as to have the amounts shown in Table 1, respectively. A polyester resin was produced in the same manner as in Example 1 except that it was not evaluated, and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 2
Ethyl acid phosphate, magnesium acetate tetrahydrate, calcium acetate dihydrate, and tetra-n-butyl titanate, each as an ethylene glycol solution, the content P as a phosphorus atom per tonne of the resulting polyester resin In addition, the content M as a magnesium atom, the content C as a calcium atom, and the content T as a titanium atom were added so as to be the amounts shown in Table 1, respectively, and these ethylene glycol solutions were added simultaneously. A polyester resin was produced in the same manner as in Example 1 except that no additional ethylene glycol was added in addition to the addition as a solution, and evaluated in the same manner. The results are shown in Table 1. It was.

Comparative Example 3
Ethyl acid phosphate, sodium acetate, and tetra-n-butyl titanate are each made into an ethylene glycol solution, in this order, sequentially at intervals of 5 minutes, the content P as phosphorus atoms per ton of the resulting polyester resin, sodium atoms The addition of the content N and the content T of the titanium atom as shown in Table 1, and the addition of ethylene glycol other than the addition of the solution. A polyester resin was produced in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

Comparative Example 4
Containing ethyl acid phosphate, magnesium acetate tetrahydrate, and tetra-n-butyl titanate as ethylene glycol solutions, in this order, sequentially at 5-minute intervals as phosphorus atoms per tonne of the resulting polyester resin A polyester resin was produced in the same manner as in Example 1 except that the amount P, the content M as a magnesium atom, and the content T as a titanium atom were added so as to be the amounts shown in Table 1, respectively. The results are shown in Table 1.

  The polyester resin of the present invention can be molded into a bottle or the like by, for example, molding into a preform by injection molding and then stretch blow molding or by blow molding a parison molded by extrusion molding. After forming into a sheet by forming, it is formed into a tray, a container or the like by thermoforming, or the sheet is biaxially stretched to form a film or the like, and particularly useful as a packaging material for food or drink. Among them, it is suitable for forming a bottle by a blow molding method in which a preform obtained by injection molding is biaxially stretched. For example, liquid seasonings such as carbonated beverages, alcoholic beverages, soy sauce, sauces, mirin, and dressings Furthermore, it is suitably used as a container for beverages such as fruit juice beverages, vitamin beverages, flavor teas, mineral waters, etc.

(A) of the step-shaped formation board for physical property evaluation shape | molded in the Example is a top view, (b) is a front view.

Claims (13)

A dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol are subjected to an esterification reaction, and (1) at least one selected from the group consisting of titanium group elements of Group 4A of the periodic table Obtained by polycondensation in the presence of a compound of a seed element, (2) a calcium compound, and (3) a phosphorus compound, as a titanium group atom of Group 4A of the periodic table derived from the compound of (1) The content as T (mole / resin ton), the content as calcium atom derived from the compound (2) as C (mole / resin ton), and the content as phosphorus atom derived from the compound as (3) Polyester characterized in that when P (mol / ton of resin) is satisfied, T, C, and P satisfy the following formulas (I) to (V), and the amount of terminal carboxyl groups is 40 equivalents / ton of resin or less. resin.
(I) 0.020 ≦ T ≦ 0.200
(II) 0.075 ≦ C ≦ 0.800
(III) 0.020 ≦ P ≦ 0.600
(IV) 0.80 ≦ C / P ≦ 4.00
(V) 1.00 ≦ C / T ≦ 20.00
Further, (4) obtained by polycondensation in the presence of a compound of at least one element selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium. The polyester resin according to claim 1 . When the content of any one of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium derived from the compound of (4) is M (mol / ton of resin), M is represented by the following formula ( The polyester resin according to claim 2 , which satisfies VI).
(VI) 0.004 ≦ M ≦ 0.800 (4) The polyester resin according to claim 2 or 3, wherein at least one element selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium is magnesium or zinc. The content of terephthalic acid units is 97.0 mol% or more with respect to all dicarboxylic acid components, the content of ethylene glycol units is 97.0 mol% or more with respect to all diol components, and the intrinsic viscosity is 0.70-0. The polyester resin according to any one of claims 1 to 4, which is 90 dl / g. The polyester resin according to any one of claims 1 to 5, wherein a color coordinate b value of Hunter's color difference formula according to the Lab color system is 4.0 or less. The polyester resin according to any one of claims 1 to 6, wherein the cyclic trimer content is 0.50% by weight or less. The polyester resin according to any one of claims 1 to 7, wherein the acetaldehyde content is 5.0 ppm or less and the acetaldehyde content in a molded article injection-molded at 280 ° C is 23 ppm or less. The polyester resin according to any one of claims 1 to 8, wherein a haze of a molded plate having a thickness of 5 mm injection-molded at 280 ° C is 10.0% or less. A dicarboxylic acid component mainly composed of terephthalic acid and a diol component mainly composed of ethylene glycol are subjected to an esterification reaction, and (1) at least one selected from the group consisting of titanium group elements of Group 4A of the periodic table In the polycondensation reaction in the presence of a compound of a seed element, (2) a calcium compound, and (3) a phosphorus compound, the addition of each compound of (1), (2), and (3) to the reaction system The amount as a titanium group atom of Group 4A of the periodic table derived from the compound of (1) per ton of the obtained polyester resin is T (mol / ton of resin), and is derived from the compound of (2) When the content as calcium atom is C (mole / resin ton) and the content as phosphorus atom derived from the compound of (3) is P (mole / resin ton), T, C, and P are the following: Esterification while satisfying the formulas (I) to (V) By adding adding ethylene glycol to respond product, process for producing a polyester resin, wherein the amount of terminal carboxyl group to produce a 40 equivalent / resin ton of the polyester resin.
(I) 0.020 ≦ T ≦ 0.200
(II) 0.075 ≦ C ≦ 0.800
(III) 0.020 ≦ P ≦ 0.600
(IV) 0.80 ≦ C / P ≦ 4.00
(V) 1.00 ≦ C / T ≦ 20.00 Further, (4) a compound of at least one element selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, copper, zinc, and gallium, When the content of any one of magnesium, aluminum, manganese, iron, cobalt, copper, zinc and gallium derived from the compound is M (mol / ton of resin), M satisfies the following formula (VI) The method for producing a polyester resin according to claim 10, which is added to the reaction system as an amount to be subjected to polycondensation in the presence of the compound.
・ 0.004 ≦ M ≦ 0.800 The order of addition of the compounds (1), (2), and (3) to the reaction system is the compound (3), the compound (2), and then the compound (1). Item 12. A method for producing a polyester resin according to Item 10 or 11. The method for producing a polyester resin according to claim 11, wherein the compound (3), the compound (4) and the compound (2) are added in this order.

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