JP5918063B2 - Method for producing copolymerized aromatic polyester - Google Patents

Description

  The present invention relates to a method for producing a polyester polymer excellent in heat resistance, moldability, and resistance to boiling water by melt polymerization using a polyethylene naphthalate resin. The copolymerized aromatic polyethylene naphthalate polymer obtained in the present invention can be suitably used for tableware and food packaging materials.

  In recent years, research and development using plastics for food packaging materials and medical materials has been vigorously conducted. In food packaging materials and medical materials, the heat resistance and gas barrier properties of molded products, as well as the resistance to boiling water and surface Hardness is required. Amorphous cyclic polyolefins are used for medical materials, and polycarbonates and aromatic polyesters are used for food container materials. However, although cyclic polyolefin is excellent in heat resistance and transparency, there is a problem in that the oxygen barrier property is low (see, for example, Patent Documents 1, 2, and 3). Aromatic polyesters have excellent oxygen barrier properties, but lack water absorption, heat resistance and transparency, and further cause a considerable decrease in molecular weight due to high molding temperature during molding (for example, Patent Document 4). (See, for example, Patent Documents 5 and 6).

  On the other hand, although copolyaromatic polyesters with improved heat resistance and reduced molecular weight during molding have been produced, the polycondensation catalyst uses heavy metals that are concerned about food safety such as antimony, and n-butyl Even when a metal having food safety such as titanate is used, there is a problem that the reaction rate is slow and the reaction rate is low, and the molecular weight of the molded product is greatly reduced to deteriorate the hue (see, for example, Patent Documents 7 and 8). ).

JP 2007-186632 A JP 2008-208237 A Japanese Patent Laid-Open No. 02-189347 JP-A-10-245433 Japanese Patent Laid-Open No. 10-017661 JP 11-293005 A Japanese Patent No. 2555377 JP 2003-277491 A

  The present invention has been achieved as a result of investigations to solve the above-mentioned problems of the prior art, and shows almost no decrease in molecular weight (decrease in intrinsic viscosity) at the time of melt molding. It is easy to provide an efficient method for producing a copolyester having heat resistance and hydrolysis resistance required for a molded product.

［上記式において、ｍ、ｎはそれぞれ独立に１以上の整数である。］
上記式（Ｉ）で表される芳香族ジオール中９５．０モル％以上が下記式（ＩＩ）で表される芳香族ジオールであり、０．１モル％以上２．５モル％以下が下記式（ＩＩＩ）で表される芳香族ジオールであって、

少なくとも下記の工程を含んでなることを特徴とする共重合芳香族ポリエステルの製造方法である。
工程１：芳香族ジカルボン酸またはその誘導体と、脂肪族ジオールおよび上記式（Ｉ）で示される芳香族ジオールとをエステル交換反応触媒を使用し０．０５ＭＰａ以上の加圧下でエステル交換反応させる工程
工程２：工程１で製造した反応物をリン化合物とゲルマニウム化合物を使用して重縮合させる工程 As a result of intensive studies to solve the above problems, the present inventor has found that a copolymer polyester having a low molecular weight drop during melt molding and a strength, heat resistance, fluidity, and excellent hydrolysis resistance necessary for a molded product is obtained. The present invention has been found by finding out that it can be provided. That is, the present invention uses an aromatic dicarboxylic acid or a derivative thereof, an aliphatic diol and an aromatic diol represented by the following formula (I) as raw materials, and the aromatic diol represented by the following formula (I) In the method for producing a copolymerized aromatic polyester having a glass transition temperature of 135 ° C. or higher, copolymerized by 55 mol% or more with respect to the components,

[In the above formula, m and n are each independently an integer of 1 or more. ]
In the aromatic diol represented by the above formula (I), 95.0 mol% or more is an aromatic diol represented by the following formula (II), and 0.1 mol% or more and 2.5 mol% or less is the following formula. An aromatic diol represented by (III),

A method for producing a copolymerized aromatic polyester, comprising at least the following steps.
Step 1: A step of transesterifying an aromatic dicarboxylic acid or derivative thereof with an aliphatic diol and the aromatic diol represented by the above formula (I) using a transesterification catalyst under a pressure of 0.05 MPa or more. 2: A step of polycondensing the reaction product produced in step 1 using a phosphorus compound and a germanium compound.

  That is, bis [4- (2-hydroxyethoxy) phenyl] sulfone represented by the above formula (I) and [4- (2-hydroxyethoxy) -4 ′-(2) represented by the above formula (II). -Hydroxyethoxyethoxy) diphenyl] sulfone, preferably 2,6-naphthalenedicarboxylic acid and / or its ester-forming derivative as an aromatic dicarboxylic acid and the like, preferably ethylene glycol as an aliphatic diol, Furthermore, two production steps, such as a step of transesterification under pressure using a calcium compound and / or a magnesium compound, and then a step of polycondensing the transesterification reaction product using a phosphorus compound and a germanium compound, Process for producing copolymerized aromatic polyester and copolymerization It is a family polyester.

  The copolymerized polyethylene naphthalate obtained by the production method of the present invention has a low molecular weight drop (decrease in intrinsic viscosity) at the time of extrusion molding or injection molding, heat resistance by load deflection temperature (HDT) evaluation, etc., and ease of melt molding. Excellent hydrolytic resistance such as fluidity and boiling water resistance. In addition, since substances that adversely affect the human body (particularly substances that exhibit endocrine disrupting effects) are not used, they can be suitably used for food container materials (especially for lunch tableware) and medical materials.

  As the aromatic dicarboxylic acid component used as a raw material in the production method of the present invention, naphthalenedicarboxylic acid is used, and preferably 2,6-naphthalenedicarboxylic acid or 2,7-naphthalenedicarboxylic acid is the main component or other 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 1,6-naphthalenedicarboxylic acid may be copolymerized. When these naphthalenedicarboxylic acids are used as raw materials, ester-forming derivatives of these naphthalenedicarboxylic acids may be used as derivatives thereof. Specific examples include dimethyl ester, diethyl ester, dipropyl ester, dibutyl ester or dihexyl ester, diphenyl ester or naphthalenedicarboxylic acid halide of naphthalenedicarboxylic acid. More preferably, 2,6-naphthalenedicarboxylic acid dimethyl ester, diethyl ester, dipropyl ester, dibutyl ester, dihexyl ester, diphenyl ester or dicarboxylic acid halide compound or 2,7-naphthalenedicarboxylic acid dimethyl ester, diethyl ester, Mention may be made of dipropyl esters, dibutyl esters, dihexyl esters, diphenyl esters or dicarboxylic acid halide compounds. Among these, 2,6-naphthalenedicarboxylic acid dimethyl ester or 2,7-naphthalenedicarboxylic acid dimethyl ester can be preferably used. Other aromatic dicarboxylic acids include, for example, terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenyl ether Aromatic dicarboxylic acids such as -4,4'-dicarboxylic acid and benzophenone-4,4'-dicarboxylic acid may be copolymerized.

  Moreover, other aliphatic dicarboxylic acid, alicyclic dicarboxylic acid, etc. can be used together in the range which does not impair the characteristic of the copolymer aromatic polyester obtained by the manufacturing method of this invention. For example, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, oxalic acid, cycloaliphatic dicarboxylic acid, decahydronaphthalenedicarboxylic acid (decalin dicarboxylic acid), norbornane dicarboxylic acid, adamantane dicarboxylic acid, etc. These may be used alone or in combination of two or more, and can be arbitrarily selected according to the purpose. Further, derivatives of these dicarboxylic acids as described above can also be used. The range that does not impair the properties of the copolymerized aromatic polyester obtained by the production method of the present invention is preferably 30 mol% or less, more preferably 20 mol%, based on all dicarboxylic acid components constituting the copolymerized aromatic polyester. Hereinafter, it is more preferably 10 mol% or less. In the copolymerized aromatic polyester obtained by the production method of the present invention, from the above viewpoint, 2,6-naphthalenedicarboxylic acid or 2,7-naphthalenedicarboxylic acid is preferably 70 mol% or more of the total dicarboxylic acid component, More preferably, it is comprised at 80 mol% or more, More preferably, it is comprised at 90 mol% or more. Further, a tri- or higher functional carboxylic acid component such as a small amount of trimellitic acid may be used, and a small amount of an acid anhydride such as trimellitic anhydride may be used. Further, a small amount of the above-described derivatives such as hydroxycarboxylic acid such as lactic acid and glycolic acid or its alkyl ester may be used and can be arbitrarily selected according to the purpose.

  In the production method of the present invention, the aromatic diol represented by the following formula (I) is copolymerized in an amount of 55 mol% or more and 99.9 mol% or less with respect to all diol components constituting the copolymerized aromatic polyester. It is characterized by. More preferably, it is 57-99 mol%, More preferably, it is copolymerized 58-90 mol%.

［上記式において、ｍ、ｎはそれぞれ独立に１以上の整数である。］

[In the above formula, m and n are each independently an integer of 1 or more. ]

  m and n are each independently an integer of 1 or more, but are not limited to one type of integer. Preferably, m and n are each independently an integer of 1 or more and 5 or less. Therefore, the aromatic diol represented by the above formula (I) may be a mixture having different numbers of m and n. Preferably, it is an aromatic diol when the combination of (m, n) is (1, 1), (2, 1), (1, 2). In the present invention, 95.0 mol% or more and 99.9 mol% or less of the aromatic diol represented by the following formula (II) in the total number of moles of the aromatic diol represented by the above formula (I) [( m, n) = (1, 1)], and an aromatic diol [(m, n) = (2, 1] in which 0.1 mol% to 2.5 mol% is represented by the following formula (III): ) Or (1,2)]. More preferably, 95.5 mol% or more and 99.5 mol% or less is an aromatic diol represented by the following formula (II), and 0.5 mol% or more and 2.4 mol% or less is represented by the following formula (III). It is that it is an aromatic diol represented by these.

  By copolymerizing the aromatic diols represented by the above formulas (I) to (III) at the above predetermined copolymerization rate, the heat resistance is high, the hydrolysis resistance is good, and the molecular weight at the time of melting is reduced. Small copolymerized aromatic polyesters can be obtained.

  In addition to the aromatic diol represented by the above formula (I) used in the production method of the present invention, an aliphatic diol is used. Preferably, glycol is used. The glycol component is mainly composed of ethylene glycol, but other glycol components can be used in combination as long as the properties of the copolymerized aromatic polyester obtained by the production method of the present invention are not impaired. For example, 1,2-propylene glycol, 1,3-propylene glycol (trimethylene glycol), butanediol, tetramethylene glycol, 1,5-pentanediol, neopentyl glycol, hexamethylene glycol (1,6-hexanediol) , 1,9-nonanediol, decamethylene glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-methyloctanediol, etc., linear or branched aliphatic diol 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,1-cyclohexanedimethanol, 1,4-dihydroxycyclohexane, 2-methyl-1,1-cyclohexanediol , Screw (4- Droxycyclohexyl) -2,2-propane, 2,2-norbornanedimethanol, 3-methyl-2,2-norbornanedimethanol, 2,3-norbornanedimethanol, 2,5-norbornanedimethanol, 2,6 -Norbornane dimethanol, perhydro-1,4: 5,8-dimethanonaphthalene-2,3-dimethanol, adamantane dimethanol, 1,3-dimethyl-5,7-adamantane dimethanol, 1,3-adamantanediol Alicyclic diols such as 1,3-dimethyl-5,7-adamantanediol; hydroquinone, catechol, resorcin, dihydroxynaphthalene, dihydroxyphenanthroline, xylylenediol [bis (hydroxymethyl) benzene], bisphenol A, bisphenol A ethylene An aromatic diol such as a xoxide adduct (2,2-bis (4-β-hydroxyethoxyphenyl) propane) or a propylene oxide adduct (2,2-bis (4-γ-hydroxypropoxyphenyl) propane); Examples include glycols having ether oxygen such as diethylene glycol, triethylene glycol, poly (oxy) ethylene glycol, polytetramethylene glycol, polymethylene glycol, and dipropylene glycol. The said diol component can be used arbitrarily according to the objective by mixing 1 type (s) or 2 or more types. From the copolymerization rate of the aromatic diol represented by the above formula (I), these aliphatic diols are preferably copolymerized in an amount of 0.1 mol% to 45 mol%. More preferably, it is 1-43 mol%, More preferably, it is 10-42 mol%.

  Furthermore, a small amount of a polyhydric alcohol component such as glycerin or pentaerythritol may be used as long as the properties of the copolymerized polyethylene naphthalate obtained by the production method of the present invention are not impaired. A small amount of an epoxy compound may be used. The range that does not impair the properties of the copolymerized polyethylene naphthalate obtained by the production method of the present invention is 30 mol% or less, preferably 20 mol% or less, based on the total glycol component. In the production of the copolyester of the present invention, the amount of all diol components including each of the above diols is 1.5 mol times or more with respect to 1 mol of the dicarboxylic acid or the ester-forming derivative of dicarboxylic acid. It is preferable that it is 2 mol times or less. When the amount of the glycol component used is less than 1.5 mol times, the esterification or transesterification reaction does not proceed sufficiently, which is not preferable. In addition, when the amount exceeds 2.2 mole times, the reaction rate is slow although the reason is not clear, and a by-product from an excessive glycol component (for example, diethylene glycol generated when ethylene glycol is excessive) A large amount is not preferable. When producing ordinary polyethylene terephthalate or polyethylene naphthalate, the amount used is relatively close to equimolar, such as 1.01 to 1.4 moles per 1 mole of dicarboxylic acid or 1 mole of ester-forming derivative of dicarboxylic acid. Used in ratio. However, in the production method of the present invention, surprisingly, the transesterification reaction does not proceed sufficiently with an amount of 1.4 mol times or less, and it is difficult to produce a copolyester having a high intrinsic viscosity. As a result of investigation, we have found that a copolymerized aromatic polyester having a sufficient intrinsic viscosity can be produced by setting the ratio of the amount used to 1.5 mol times to 2.2 mol times.

  A transesterification catalyst is used for the transesterification reaction, and the transesterification catalyst is preferably a manganese compound, a titanium compound, a calcium compound, or a magnesium compound from the viewpoint of reactivity, and is also effective as a color adjusting agent. Although a compound is preferable, when considering food safety, it is particularly preferable to use a calcium compound or a magnesium compound. When using these transesterification reaction catalysts, they may be used alone or in combination. In addition, these metal compounds preferably use acetates of these metals because they are inexpensive, easily available, and easy to handle. Specifically, manganese acetate, calcium acetate, magnesium acetate, and cobalt acetate. These transesterification catalysts are preferably used in the range of 8 to 120 mmol% with respect to all dicarboxylic acid components constituting the copolymer polyester. More preferably, it is 25-80 mmol%.

  The stabilizer added to the transesterification reactor after the transesterification reaction is preferably a phosphorus compound, and is composed of orthophosphoric acid, phosphorous acid, hypophosphorous acid, trimethyl phosphate, other phosphoric acid triester compounds, phosphoric acid diester compounds or phosphoric acid. Various organic and inorganic phosphorus compounds such as monoester compounds, phenylphosphonic acid and other phosphonic acid compounds, phosphonic acid ester compounds, phosphinic acid compounds, and phosphinic acid ester compounds can be mentioned. In terms of suppressing coloring of the product, it is preferable to use trimethyl phosphate and phosphonoacetic acid triethyl (triethylphosphonoacetate). These phosphorus compounds preferably deactivate the transesterification catalyst, suppress side reactions during the polycondensation reaction, and do not inhibit the polycondensation reaction.

  The phosphorus compound described above is preferably used so that the phosphorus element derived from the phosphorus compound is contained in an amount of 10 to 150 mmol% with respect to all dicarboxylic acid components constituting the copolymer polyester. More preferably, it is 20-120 mmol%, More preferably, it is 30-100 mmol%. If the content of the phosphorus compound is less than the lower limit, the color tone of the copolymerized aromatic polyester tends to be lowered, and if the content exceeds the upper limit, the polycondensation reaction is difficult to proceed.

  Examples of the polycondensation catalyst used in the production method of the present invention include an antimony compound, a titanium compound, a germanium compound, and the like, but it is preferable to use a germanium compound from the viewpoint of food safety and reactivity. More preferably, amorphous germanium dioxide is used. These germanium compounds are preferably used so that the germanium element derived from the germanium compound is contained in an amount of 30 to 100 mmol% with respect to all dicarboxylic acid components constituting the copolymerized aromatic polyester. More preferably, it is 40-90 mmol%, More preferably, it is 50-80 mmol%.

In the method for producing a copolymerized aromatic polyester having the above composition in the present invention, it is necessary to include at least the following steps.
Step 1: A step of transesterifying an aromatic dicarboxylic acid or derivative thereof with an aliphatic diol and an aromatic diol represented by the following formula (I) using a transesterification catalyst under a pressure of 0.05 MPa or more. 2: A step of polycondensing the reaction product produced in Step 1 using a phosphorus compound and a germanium compound In Step 1 of the production method of the present invention, the above aromatic dicarboxylic acid or derivative thereof, aliphatic diol and the following formula ( It is produced by subjecting the aromatic diol represented by I) to a pressure reaction in the presence of the transesterification reaction catalyst. The reaction temperature of the transesterification reaction is preferably 150 ° C. or higher, and the temperature is preferably raised as the reaction proceeds. The upper limit in this case is 250 ° C., that is, 250 ° C. or less, and more preferably 240 ° C. or less. In the pressurization reaction, it is preferable to use an inert gas atmosphere such as nitrogen or argon. In addition, the reaction tank in this process 1 may be either a vertical reaction tank or a horizontal reaction tank, and other production equipment used in a normal polyester production process can be used.

  In the manufacturing method of the process 1 of this invention, the internal pressure of a reaction tank is 0.05 MPa or more, Furthermore, 0.05 MPa or more and 1.50 MPa or less are preferable. More preferably, it is 0.06-1.00 MPa, More preferably, it is 0.07-0.80 MPa. When the internal pressure is less than 0.05 MPa, when the aromatic diol of the following formula (I) is reacted at 55 mol% or more, not only the reaction rate becomes slow, but also the transesterification rate falls below 80%. The polycondensation reaction in may not proceed. If the internal pressure of the reaction is 1.50 MPa or more, methanol produced as a by-product during the reaction cannot be efficiently discharged out of the reaction tank, and as a result, the reaction time becomes longer and the production efficiency decreases due to the lower reaction temperature. .

［上記式において、ｍ、ｎはそれぞれ独立に１以上の整数である。］

[In the above formula, m and n are each independently an integer of 1 or more. ]

  In the production method of Step 1 of the present invention, the transesterification rate is preferably 80% or more. If the reaction rate is less than 80%, the unreacted aromatic dicarboxylic acid or its derivative is sublimated during the reaction in Step 2, which adversely affects the degree of decompression in the polycondensation reaction tank, and the polycondensation reaction. May not progress. Therefore, as described above, we have found a method for producing a copolymerized aromatic polyester having a high transesterification rate in a short time by performing a transesterification reaction using nitrogen instead of atmospheric pressure. It was. After the transesterification reaction under pressure has been completed, the transesterification reaction is not performed immediately, but rather the transition to the polycondensation reaction. It is also preferable to carry out. In some cases, it is possible to reduce unreacted raw materials and the like in the transesterification reaction and suppress the formation of sublimates during the polycondensation reaction.

  In the prior art disclosed in the above Patent Document 7 and Patent Document 8, etc., aromatic dicarboxylic acid, aliphatic diol and aromatic diol are produced by atmospheric pressure reaction. In the production method of the present invention, Is characterized by efficiently increasing the molecular weight of the copolymerized aromatic polyester using a monomer having a high transesterification reaction rate, which is reacted in a pressure reaction of a predetermined pressure or higher in Step 1. According to this aspect, the properties possessed by the copolymerized aromatic polyester obtained in the prior art are greatly improved so that a high-quality copolymerized aromatic polyester can be produced economically and efficiently and stably. became.

  The intrinsic viscosity of the copolymerized aromatic polyester after Step 2 obtained by the production method of the present invention is preferably 0.50 to 0.65 dL / g from the viewpoint of mechanical strength and moldability. When the intrinsic viscosity is less than 0.50 dL / g, the mechanical strength is inferior, and when it exceeds 0.65 dL / g, the fluidity is lowered and the molding processability is inferior. In order to make the intrinsic viscosity within this numerical range, the transesterification rate is sufficiently increased so that unreacted raw materials are eliminated in the step 1 described above, and a sufficiently high vacuum is applied in the polycondensation reaction step 2 in the step 2. One example is to perform the melt polycondensation reaction for a sufficient amount of time. When it is difficult to perform melt polycondensation, solid phase polymerization may be performed.

  The glass transition temperature of the copolymerized aromatic polyester obtained by the production method of the present invention is preferably 135 ° C. or higher, more preferably 136 ° C. or higher. If the glass transition temperature is less than 135 ° C., the heat resistance of the molded product is inferior, which may be undesirable. In order to make the glass transition temperature within this range, the aromatic diol represented by the following formula (I) is copolymerized in an amount of 55 mol% or more based on the total diol components constituting the copolymerized aromatic polyester, In the aromatic diol represented by the formula (I), 95.0 mol% or more is an aromatic diol represented by the following formula (II), and 0.1 mol% or more and 2.5 mol% or less is represented by the following formula ( And an aromatic diol represented by III).

［上記式において、ｍ、ｎはそれぞれ独立に１以上の整数である。］

[In the above formula, m and n are each independently an integer of 1 or more. ]

The terminal carboxyl concentration of the copolymerized aromatic polyester obtained by the production method of the present invention is preferably 25 eq (equivalent) / T (1T = 10 ³ kg) or less, and more preferably 20 eq / T or less. If the terminal carboxyl concentration exceeds 25 eq / T, the hydrolysis resistance of the molded product is inferior, which is not preferable. In order to make the terminal carboxyl concentration within this range, this terminal carboxyl concentration range can be achieved by adjusting the transesterification rate in step 1 and the polycondensation reaction time in step 2. .

Molding flowability of the copolymerized aromatic polyester obtained by the production method of the present invention is preferably at least 50 cm ³ / 10min, it is more preferably 52cm ³ / 10min or more. If molding fluidity is less than 50 cm 3 ^/ 10min, not only it is impossible to increase the molding cycle, undesirably causes a decrease in molecular weight of the molded article becomes longer residence time during melt molding. In order to make the molding fluidity within the range of this value, the copolymerization rate of the compound represented by the above formula (I) is set to 55 mol% or more when the copolymerized aromatic polyester is produced, and the intrinsic viscosity is set. This range of molding fluidity values can be achieved by adjusting between 0.50 and 0.65 L / g.

  The deflection temperature under load of 1.80 MPa of the copolyester obtained by the production method of the present invention is preferably 100 ° C. or higher, more preferably 110 ° C. or higher from the viewpoint of the physical properties of the molded product. If the deflection temperature under load is 100 ° C. or lower, the heat resistance of the molded product is inferior, which is not preferable. In order to make the deflection temperature under this range, when the copolymerized aromatic polyester is produced, 55 mol% or more of the aromatic diol represented by the above formula (I) is copolymerized, and the aromatic In the diol, the content of the compounds represented by the above formulas (II) and (III) is 95.0 mol% or more, 0.1 mol% or more and 2.5% or less, respectively, and the intrinsic viscosity is 0.50 to 0.50. By adjusting between 0.65 dL / g, this load deflection temperature value range can be achieved.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to a following example, unless the summary is exceeded. The physical properties of the obtained copolymer polyethylene naphthalate were measured by the following methods.

(1) Intrinsic Viscosity (IV) Measurement According to a conventional method, it was measured at 35 ° C. in orthochlorophenol as a solvent.

(2) Measurement of glass transition temperature (Tg) Copolymer aromatic polyester dried under reduced pressure at 25 ° C. for 24 hours was measured using a differential scanning calorimeter (DSC) while increasing the temperature at a temperature increase rate of 10 ° C./min. About 10 mg of a measurement sample was weighed in an aluminum pan (TA Instruments) and measured under a nitrogen atmosphere.

(3) Copolymerization rate calculation The copolymerization rate in the copolymerized aromatic polyester obtained by the production method of the present invention was determined by measuring a ¹ H-NMR spectrum at 600 MHz using JEOLA-600 manufactured by JEOL. The peak area of the hydrogen atoms constituting the methylene group belonging to the aromatic diol of (I) (4 (m + n) per molecule = 4p) is A, and the hydrogen atoms constituting the methylene group in ethylene glycol When the peak area of (4 per molecule) is B and the peak area of hydrogen atoms (8 per molecule) constituting the methylene group in diethylene glycol is C,
The copolymerization rate of the above formula (I) aromatic diol is:
[A / 4p] / ([A / 4p] + [B / 4] + [C / 8]) = 2A / (2A + 2pB + pC)
It can be calculated by Similarly, the copolymerization rate of ethylene glycol is
2pB / (2A + 2pB + pC) × 100
The copolymerization rate of diethylene glycol considered to be the remaining diol component was calculated by subtracting the copolymerization rate of these components from 100%.

(4) Terminal carboxyl concentration (terminal COOH) measurement It is the value which melt | dissolved the copolymer aromatic polyester in benzyl alcohol, and titrated with 0.1N-NaOH, and is the carboxyl equivalent per 1 * 10 < ⁶ > g.

(5) Fluidity The melt volume rate (MVR) was measured as an index of fluidity of the copolymerized aromatic polyester. The obtained pellets were measured in accordance with ISO 1133 standards. The larger the MVR value, the better the fluidity and the easier the molding, while the smaller the MVR value, the worse the fluidity and the harder the molding.

(6) Measurement of deflection temperature under load The copolymerized aromatic polyester obtained by the present invention was measured according to the method of ISO 75.

(7) Hydrolysis resistance Using a test tank called a pressure cooker tank, the molded product was treated in the test tank at 110 ° C. for 100 hours, the IV before and after that was measured, and the retention rate was calculated. did.
IV retention (%) = (IV after treatment) / (IV before treatment) × 100
IV retention rate of 95% or more is judged as good hydrolysis resistance ○, 90% or more and less than 95% is judged as slightly good hydrolysis resistance Δ, less than 90% hydrolysis resistance It was judged as poor sex and marked with x.

(8) Measurement of decrease in intrinsic viscosity (ΔIV) during melt molding The copolymerized aromatic polyester obtained in Examples 1 to 6 and Comparative Examples 1 to 5 was set at a cylinder temperature of 265 ° C and a mold temperature of 70 ° C. The polyethylene naphthalate obtained in Comparative Examples 6 to 7 was injection molded at a cylinder temperature of 300 ° C and a mold temperature of 80 ° C. The IV of the molded product molded under these conditions was measured, and ΔIV was calculated using the following formula.
ΔIV = (IV of chip) − (IV of molded product)

(9) Concentration of contained elements (P, Ge)
It measured by the usual method from the molded article of copolyester by the fluorescent X ray (Rigaku make, Rataflex RU200).

[Example 1]
60 parts by weight of 2,6-naphthalenedicarboxylic acid dimethyl ester as a divalent dicarboxylic acid, 22 parts by weight of ethylene glycol as a divalent diol, and further a bisphenol S ethylene oxide bimolecular adduct as a copolymerization component (the above formula ( The content of the aromatic diol represented by II), the same shall apply hereinafter) is 99.1 mol%, and the content of the trimolecular adduct (the aromatic diol represented by the above formula (III), the same shall apply hereinafter). 50 parts by weight of a bisphenol S derivative (aromatic diol represented by the above formula (I), the same shall apply hereinafter) having 0.6 mol% and calcium acetate monohydrate as a transesterification catalyst. 20 mmol% as a total amount with respect to the number of moles, and 50 mmol% with respect to the number of moles of divalent dicarboxylic acid as magnesium acetate tetrahydrate, The reaction temperature under pressure of .08MPa makes a transesterification reaction while elevating to be a 245 ° C.. When the reaction temperature reached 245 ° C., the system was returned to normal pressure over 10 minutes, and the reaction was maintained for another 40 minutes. After 40 minutes, amorphous germanium dioxide was added in a total amount of 60 mmol% based on the number of moles of divalent dicarboxylic acid, and after 15 minutes, trimethyl phosphate was added in a total amount of 70 mmol% based on the number of moles of divalent dicarboxylic acid. Reacted. When the reaction temperature reached 250 ° C., the reaction product was transferred to a polycondensation reaction tank to start a polycondensation reaction.

The polycondensation reaction is gradually reduced from normal pressure to 0.133 kPa (1 Torr) over 50 minutes, and at the same time, the temperature is raised to a predetermined reaction temperature of 295 ° C., and thereafter the predetermined polymerization temperature is 0.133 kPa (1 Torr). And a polycondensation reaction was carried out for 30 minutes.
When 180 minutes have elapsed from the start of the polycondensation reaction, the polycondensation reaction is completed, and the copolymerized polyethylene naphthalate is extracted. Intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, concentration of phosphorus element contained The germanium element concentration was measured, and the fluidity, the intrinsic viscosity of the molded article, and the deflection temperature under load were measured. The results are shown in Table 1. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 61 mmol% and 68 mmol%, respectively, with respect to the carboxylic acid.

[Example 2]
Copolymerized polyethylene naphthalate was obtained in the same manner as in Example 1 except that the phosphorus compound was changed to triethyl phosphonoacetate. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, phosphorous element concentration and germanium element concentration of the copolymerized polyethylene naphthalate obtained, and also the fluidity and intrinsic viscosity of the molded product. The deflection temperature under load and the hydrolysis resistance were evaluated, and the results are shown in Table 1. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 60 mmol% and 70 mmol%, respectively, with respect to the carboxylic acid.

[Example 3]
A copolymer polyethylene naphthalate was obtained in the same manner as in Example 1 except that the content of the bisphenol S ethylene oxide bimolecular adduct was changed to 95.8 mol% and the content of the trimolecular adduct was changed to 2.1 mol%. It was. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, phosphorous element concentration and germanium element concentration of the copolymerized polyethylene naphthalate obtained, and also the fluidity and intrinsic viscosity of the molded product. The deflection temperature under load and the hydrolysis resistance were evaluated, and the results are shown in Table 1. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 59 mmol% and 71 mmol%, respectively, with respect to the carboxylic acid.

[Example 4]
A copolymerized polyethylene naphthalate was obtained in the same manner as in Example 3 except that the phosphorus compound was changed to triethyl phosphonoacetate. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, phosphorous element concentration and germanium element concentration of the copolymerized polyethylene naphthalate obtained, and also the fluidity and intrinsic viscosity of the molded product. The deflection temperature under load and the hydrolysis resistance were evaluated, and the results are shown in Table 1. As a result of the measurement, the germanium element concentration and phosphorus concentration in the copolymerized polyethylene naphthalate were 58 mmol% and 67 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 1]
A copolymer polyethylene naphthalate was obtained in the same manner as in Example 1 except that the content of bisphenol S ethylene oxide bimolecular adduct was changed to 97.0 mol% and the content of trimolecular adduct was changed to 3.0 mol%. It was. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, phosphorous element concentration and germanium element concentration of the copolymerized polyethylene naphthalate obtained, and also the fluidity and intrinsic viscosity of the molded product. The deflection temperature under load and the hydrolysis resistance were evaluated, and the results are shown in Table 1. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 61 mmol% and 69 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 2]
Copolymerized polyethylene naphthalate was obtained in the same manner as in Comparative Example 1 except that the phosphorus compound was changed to triethyl phosphonoacetate. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group, copolymerization rate, phosphorous element concentration / germanium element concentration of the obtained copolymer polyethylene naphthalate, flowability, intrinsic viscosity of the molded product, The deflection temperature under load and hydrolysis resistance were evaluated, and the results are shown in Table 1. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 59 mmol% and 70 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 3]
A copolymer polyethylene naphthalate was obtained in the same manner as in Comparative Example 1 except that the content of bisphenol S ethylene oxide bimolecular adduct was changed to 88.0 mol% and the content of trimolecular adduct was changed to 9.8 mol%. It was. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, phosphorous element concentration and germanium element concentration of the copolymerized polyethylene naphthalate obtained, and also the fluidity and intrinsic viscosity of the molded product. The deflection temperature under load and the hydrolysis resistance were evaluated, and the results are shown in Table 1. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 62 mmol% and 68 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 4]
Copolymerized polyethylene naphthalate was obtained in the same manner as in Comparative Example 3 except that the phosphorus compound was changed to triethyl phosphonoacetate. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group, copolymerization rate, phosphorous element concentration / germanium element concentration of the obtained copolymer polyethylene naphthalate, flowability, intrinsic viscosity of the molded product, The deflection temperature under load and hydrolysis resistance were evaluated, and the results are shown in Table 2. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 60 mmol% and 71 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 5]
The divalent dicarboxylic acid is 60 parts by weight of 2,6-naphthalenedicarboxylic acid dimethyl ester, the divalent diol is 22 parts by weight of ethylene glycol, and the copolymer component contains bisphenol S ethylene oxide bimolecular adduct. 50 parts by weight of a bisphenol S derivative having a content of 99.1 mol% and a trimolecular adduct of 0.6 mol%, and calcium acetate and magnesium acetate as a transesterification catalyst with respect to the number of moles of divalent dicarboxylic acid The total amount was 20 and 70 mmol%, respectively, and the ester exchange reaction was carried out at normal pressure while raising the reaction temperature to 220 ° C. The reaction was maintained for 40 minutes after the reaction temperature reached 220 ° C. After 40 minutes, germanium dioxide was added in a total amount of 60 mmol% with respect to the number of moles of divalent dicarboxylic acid, and after another 15 minutes, trimethyl phosphate was added with divalent dicarboxylic acid. The reaction was carried out with a total amount of 70 mmol% added to the number of moles of acid. When the reaction temperature reached 240 ° C., the reaction product was transferred to a polycondensation reaction tank to start a polycondensation reaction.

The polycondensation reaction is gradually reduced from normal pressure to 0.133 kPa (1 Torr) over 50 minutes, and at the same time, the temperature is raised to a predetermined reaction temperature 295. Thereafter, a predetermined polymerization temperature of 0.133 kPa (1 Torr) is maintained. The polycondensation reaction was carried out for 30 minutes while maintaining.
When 180 minutes have elapsed from the start of the polycondensation reaction, the polycondensation reaction is completed, and the copolymerized polyethylene naphthalate is extracted. Intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, concentration of phosphorus element contained -The germanium element concentration was measured, and the fluidity, the intrinsic viscosity of the molded product, the deflection temperature under load, and the hydrolysis resistance were evaluated. The results are shown in Table 2. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 61 mmol% and 69 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 6]
Copolymerized polyethylene naphthalate was obtained in the same manner as in Comparative Example 5 except that the phosphorus compound was changed to triethyl phosphonoacetate. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group, copolymerization rate, phosphorous element concentration / germanium element concentration of the obtained copolymer polyethylene naphthalate, flowability, intrinsic viscosity of the molded product, The deflection temperature under load and hydrolysis resistance were evaluated, and the results are shown in Table 2. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 58 mmol% and 72 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 7]
A copolymer polyethylene naphthalate was obtained in the same manner as in Comparative Example 5 except that the content of the bisphenol S ethylene oxide bimolecular adduct was changed to 97.0 mol% and the content of the trimolecular adduct was changed to 3.0 mol%. It was. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, phosphorous element concentration and germanium element concentration of the copolymerized polyethylene naphthalate obtained, and also the fluidity and intrinsic viscosity of the molded product. The deflection temperature under load and the hydrolysis resistance were evaluated, and the results are shown in Table 2. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 59 mmol% and 68 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 8]
Copolymerized polyethylene naphthalate was obtained in the same manner as in Comparative Example 7 except that the phosphorus compound was changed to triethyl phosphonoacetate. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group, copolymerization rate, phosphorous element concentration / germanium element concentration of the obtained copolymer polyethylene naphthalate, flowability, intrinsic viscosity of the molded product, The deflection temperature under load and hydrolysis resistance were evaluated, and the results are shown in Table 2. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 61 mmol% and 70 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 9]
A copolymer polyethylene naphthalate was obtained in the same manner as in Comparative Example 5 except that the content of bisphenol S ethylene oxide bimolecular adduct was changed to 88.0 mol% and the content of trimolecular adduct was changed to 9.8 mol%. It was. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group concentration, copolymerization rate, phosphorous element concentration and germanium element concentration of the copolymerized polyethylene naphthalate obtained, and also the fluidity and intrinsic viscosity of the molded product. The deflection temperature under load and the hydrolysis resistance were evaluated, and the results are shown in Table 2. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 58 mmol% and 69 mmol%, respectively, with respect to the carboxylic acid.

[Comparative Example 10]
Copolymerized polyethylene naphthalate was obtained in the same manner as in Comparative Example 9 except that the phosphorus compound was changed to triethyl phosphonoacetate. Measure the intrinsic viscosity, glass transition temperature, terminal carboxyl group, copolymerization rate, phosphorous element concentration / germanium element concentration of the obtained copolymer polyethylene naphthalate, flowability, intrinsic viscosity of the molded product, The deflection temperature under load and hydrolysis resistance were evaluated, and the results are shown in Table 2. As a result of the measurement, the germanium element concentration and phosphorus element concentration in the copolymerized polyethylene naphthalate were 60 mmol% and 69 mmol%, respectively, with respect to the carboxylic acid.

  The copolymerized polyethylene naphthalate obtained by the present invention has a low molecular weight drop during extrusion molding and injection molding, heat resistance by load deflection temperature (HDT) evaluation, etc., fluidity as an index of ease of melt molding, boiling water resistance It has excellent hydrolysis resistance such as stability. In addition, since it does not use substances that adversely affect the human body (especially substances that exhibit endocrine disrupting effects), it can be suitably used for food container materials (especially for dinner tableware) and medical materials. Is big.

Claims (3)

Using aromatic dicarboxylic acid or a derivative thereof, an aliphatic diol and an aromatic diol represented by the following formula (I) as raw materials, the aromatic diol represented by the following formula (I) is 55 moles based on the total diol component. % In the method for producing a copolymerized aromatic polyester having a glass transition temperature of 135 ° C. or higher,

[In the above formula, m and n are each independently an integer of 1 or more. ]
In the aromatic diol represented by the above formula (I), 95 mol% or more is an aromatic diol represented by the following formula (II), and 0.1 mol% or more and 2.5 mol% or less is represented by the following formula (III) An aromatic diol represented by:

A method for producing a copolymerized aromatic polyester, comprising at least the following steps.
Step 1: A step of transesterifying an aromatic dicarboxylic acid or derivative thereof with an aliphatic diol and the aromatic diol represented by the above formula (I) using a transesterification catalyst under a pressure of 0.05 MPa or more. 2: A step of polycondensing the reaction product produced in step 1 using a phosphorus compound and a germanium compound.   After the completion of the step 2, the phosphorus element derived from the phosphorus compound is contained in an amount of 10 to 150 mmol% with respect to all dicarboxylic acid components constituting the copolymerized aromatic polyester, and the germanium element derived from the germanium compound is contained. 2. The method for producing a copolymerized aromatic polyester according to claim 1, comprising 30 to 100 mmol% with respect to all of the aromatic dicarboxylic acid components constituting the copolymerized aromatic polyester.   The method for producing a copolymerized aromatic polyester according to claim 1 or 2, wherein the intrinsic viscosity of the copolymerized aromatic polyester obtained in step 2 is 0.50 to 0.65 dL / g.