Copolyester ether having polyethylene furanoate as main component

Abstract

To provide a PEF-based resin that improves crystallization speed and flowability while retaining superior heat resistance derived from PEF, and a molded article mainly composed thereof.SOLUTION: A copolyester ether is mainly composed of a dicarboxylic acid component and a diol component, wherein the dicarboxylic acid component is mainly composed of a 2,5-furandicarboxylic acid component, and the diol component is mainly composed of an ethylene glycol component and includes a polytrimethylene ether glycol component. A molded article is mainly composed of the copolyester ether, the molded article being one of a fiber, a film, a sheet, and a bottle.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a copolymerized polyester ether containing polyethylene furanoate as a main component. [Background technology]

[0002] Polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is a hard, general-purpose polyester material with excellent moldability and heat resistance, and is used in a variety of applications, including fibers, films, bottles, etc. Terephthalic acid, the raw material for PET, is often derived from fossil fuels, which places a heavy burden on the environment.

[0003] Polyethylene furanoate (hereinafter sometimes abbreviated as PEF) is an environmentally friendly alternative to PET. Furandicarboxylic acid, the raw material for PEF, can be produced from plant-derived materials and is already commercially available. PEF has excellent heat resistance, although it is somewhat inferior to PET, and also has very good gas barrier properties compared to PET.

[0004] Patent Document 1 states that PEF has a slow crystallization rate, which may cause problems in the manufacturing process and molding process. Patent Document 1 also discloses a PEF-based copolymer polyester resin that contains 0.1 to 8 mol % of aliphatic dicarboxylic acid units having 2 to 36 carbon atoms relative to all dicarboxylic acid units and / or 0.1 to 8 mol % of aliphatic diol units having 3 to 20 carbon atoms relative to all diol units, and describes that the heat of fusion after heat treatment at 120°C for 6 hours is higher than that of PEF, making it more susceptible to crystallization. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2013-155388 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, although not mentioned in Patent Document 1, PEF has a problem of poor melt fluidity. Because its melt viscosity is significantly higher than that of PET with a comparable intrinsic viscosity, when PEF is produced by melt polymerization, it must be removed from the polymerization vessel before a sufficiently high intrinsic viscosity is reached. To obtain PEF with a higher intrinsic viscosity, solid-state polymerization of the resin after melt polymerization is considered. However, PEF has a relatively slow crystallization rate compared to amorphous materials, making it prone to blocking during the solid-state polymerization process. Blocking is also likely to occur during the drying process. While prior crystallization at low temperatures for a long period of time is effective in avoiding blocking during the solid-state polymerization and drying processes, this reduces productivity. Therefore, increasing melt fluidity in addition to increasing crystallization rate is important for improving productivity in the PEF resin manufacturing process. Furthermore, increasing melt fluidity and crystallinity are important for ensuring productivity in the molding process and the quality of molded products.

[0007] The present invention was made in response to the problems of the prior art. That is, an object of the present invention is to obtain a PEF-based resin that has improved crystallization rate and fluidity while retaining the excellent heat resistance inherent to PEF. [Means for solving the problem]

[0008] To achieve the above objectives, the present inventors focused on modifying PEF by copolymerizing flexible polyalkylene ether glycols and investigated the structure, amount of polyalkylene ether glycol added, and molecular weight of the polyalkylene ether glycols. As a result, they found that copolymerizing polyalkylene ether glycols, which tend to phase separate from PEF, improves the crystallization rate and reduces the decrease in parameters indicating heat resistance, such as the melting point and glass transition temperature. They also found that copolymerizing polyalkylene ether glycols reduces the melt viscosity.

[0009] That is, the present invention has the following configuration. Section 1. The copolymer is mainly composed of a dicarboxylic acid component and a diol component, the dicarboxylic acid component is primarily composed of a 2,5-furandicarboxylic acid component; the diol component is primarily composed of an ethylene glycol component and includes a polytrimethylene ether glycol component; Copolymerized polyester ether. Section 2. Item 2. The copolymerized polyester ether according to Item 1, wherein the content of the polytrimethylene ether glycol component is 0.1 to 5 mol % based on the total amount of the diol component. Section 3. Item 3. The copolymerized polyester ether according to item 1 or 2, wherein the polytrimethylene ether glycol component has a number average molecular weight of 300 to 5,000. Section 4. Item 4. The copolymerized polyester ether according to any one of Items 1 to 3, wherein a sea-island structure is observed when observed under a transmission electron microscope. Section 5. Item 5. The copolymerized polyester ether according to Item 4, wherein the island domains of the sea-island structure occupy an area of ​​0.1% or more and have an average diameter of 20 nm or more. Section 6. Item 6. The copolymerized polyester ether according to any one of Items 1 to 5, wherein the heat of fusion when melted at 300°C, rapidly cooled to -50°C at a rate of 20°C / min, and then heated again to 300°C at a rate of 2°C / min, is 5 J / g or more and 50 J / g or less as measured by a differential scanning calorimeter. Section 7. Item 7. The copolymerized polyester ether according to any one of Items 1 to 6, wherein the copolymerized polyester ether has a glass transition temperature of 50°C or higher when melted at 300°C, rapidly cooled to -50°C at a rate of 20°C / min, and then heated again to 300°C at a rate of 2°C / min as measured by a differential scanning calorimeter. Section 8. Item 8. The copolymerized polyester ether according to any one of Items 1 to 7, wherein the copolymerized polyester ether has a melting point of 200°C or higher when melted at 300°C, rapidly cooled to -50°C at a rate of 20°C / min, and then heated again to 300°C at a rate of 2°C / min as measured by a differential scanning calorimeter. Section 9. Item 9. The copolymerized polyester ether according to any one of items 1 to 8, having an elastic modulus of 1500 MPa or more. Section 10. Item 10. A molded article which is mainly composed of the copolymerized polyester ether according to any one of items 1 to 9 and is in the form of a fiber, a film, a sheet, or a bottle. [Effects of the Invention]

[0010] The copolymerized polyester ether of the present invention has a crystallization rate and flowability superior to those of PEF while retaining the excellent heat resistance and tensile properties inherent to PEF. Therefore, a copolymerized polyester ether with excellent productivity and processing characteristics can be obtained. Furthermore, since the copolymerized polyester ether has hydrolysis resistance equivalent to or greater than that of PEF, it is expected to exhibit durability equivalent to or greater than that of PEF in a variety of applications. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an example of a cavity diagram of PEF and copolymerized polyester ether. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Composition Description) The present invention will be described in detail below. The copolymerized polyester ether of the present invention is primarily composed of a dicarboxylic acid component and a diol component. The dicarboxylic acid component is primarily composed of 2,5-furandicarboxylic acid. The diol component is primarily composed of ethylene glycol and includes a polytrimethylene ether glycol component. Here, "primarily composed" means that each component independently accounts for 90 mol% or more, and may account for 94 mol% or more, 96 mol% or more, 98 mol% or more, or even 100 mol%.

[0013] Polyalkylene ether glycol components, such as polytrimethylene ether glycol components, are chemically stable and therefore do not inhibit the formation and maintenance of PEF chains during the production and use of copolymerized polyester ethers. Furthermore, polyalkylene ether glycol components have poor compatibility with PEF chains and tend to aggregate to form microphase-separated structures. Therefore, they are less likely to be mixed into the crystalline regions of PEF chains, thereby preventing a decrease in the inherently high melting point of the PEF chains. Furthermore, the highly flexible polyalkylene ether glycol component linked to the PEF chains increases the mobility of the PEF chains, thereby improving the crystallization rate of the PEF chains. While the PEF chains may be linked via a chain extender, direct linkage is preferred to obtain copolymerized polyester ethers with a high melting point.

[0014] The dicarboxylic acid component constituting the copolymerized polyester ether is primarily composed of a 2,5-furandicarboxylic acid component. The ratio of the 2,5-furandicarboxylic acid component to the total dicarboxylic acid component is preferably 90 mol% or more, more preferably 94 mol% or more, even more preferably 96 mol% or more, even more preferably 98 mol% or more, and may even be 100 mol%. As an aromatic dicarboxylic acid component other than 2,5-furandicarboxylic acid, one or more aromatic dicarboxylic acids having 8 to 22 carbon atoms may be contained. Specific examples include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 2,3-furandicarboxylic acid, 2,4-furandicarboxylic acid, and 3,4-furandicarboxylic acid.

[0015] The diol component constituting the copolymerized polyester ether is mainly composed of an ethylene glycol component and also contains a polytrimethylene ether glycol component. The ratio of the ethylene glycol component to the total diol component is preferably 90 mol% or more, more preferably 94 mol% or more, even more preferably 96 mol% or more, even more preferably 98 mol% or more, and may even be 100 mol%. The diol component constituting the copolymerized polyester ether other than the ethylene glycol component and the polytrimethylene ether glycol component is not particularly limited, but examples thereof include linear polyalkylene ether glycol components in which the alkylene group has a carbon number other than 3.

[0016] When the alkylene group of the linear polyalkylene ether glycol component has three or more carbon atoms, the linear polyalkylene ether glycol component and the PEF chain undergo phase separation, resulting in an excellent crystallization rate. On the other hand, the greater the carbon number of the alkylene group, the lower the compatibility between the linear polyalkylene ether glycol component and the PEF chain, and the more likely phase separation occurs. However, if this tendency is excessive, it acts to inhibit the mobility of the PEF chain, resulting in a decrease in the crystallization rate. Therefore, it is preferable that the diol component other than ethylene glycol that constitutes the copolymerized polyester ether be polytrimethylene ether glycol as the main component. Alternatively, the polyalkylene glycol mixture may contain, as a minor component, a polyalkylene ether glycol having an alkylene group with two and / or four carbon atoms, or polytrimethylene ether glycol having an alkylene group with three carbon atoms.

[0017] The content of the polytrimethylene ether glycol component is preferably 0.1 to 5 mol %, more preferably 0.1 to 3 mol %, even more preferably 0.2 to 2 mol %, and particularly preferably 0.2 to 1.5 mol %, based on the total diol component. When the content of the polytrimethylene ether glycol component is within this range, a copolymerized polyester ether having a high crystallization rate, elastic modulus, and melting point can be obtained.

[0018] The number average molecular weight of the polytrimethylene ether glycol and other polyalkylene ether glycols constituting the copolymerized polyester ether is preferably 300 to 5000, more preferably 500 to 4000, and even more preferably 800 to 3000. When the number average molecular weight is within this range, the polyalkylene ether glycol component and the PEF chain tend to undergo phase separation and form a sea-island structure, and if released into the environment, they tend to be easily decomposed by microorganisms in the environment.

[0019] Even if the alkylene group constituting the polyalkylene glycol has 3 carbon atoms, if the alkylene group has a side chain, the crystallinity of the copolymerized polyester ether will be reduced. Therefore, a straight-chain polyalkylene ether glycol is used, but since it may be contained as an impurity in the raw material, the side-chain polyalkylene ether glycol may be contained up to 5 mol % of the total polyalkylene ether glycol, more preferably less than 1 mol %, and even more preferably less than 0.1 mol %.

[0020] The diol component constituting the copolymerized polyester ether is primarily composed of an ethylene glycol component and also contains a polytrimethylene ether glycol component. The ratio of the ethylene glycol component to the total diol component is preferably 90 mol% or more, more preferably 94 mol% or more, even more preferably 96 mol% or more, even more preferably 98 mol% or more, and may be 100 mol%. When the ratio of the ethylene glycol component is within this range, the copolymerized polyester ether also exhibits the high heat resistance characteristic of the PEF chain.

[0021] The diol component in the copolymerized polyester ether contains ethylene glycol and polytrimethylene ether glycol components, but ethylene glycol-derived components such as diethylene glycol, triethylene glycol, and oligoethylene glycols with higher polymerization degrees, which are produced by condensation between ethylene glycols during the production of the copolymerized polyester ether, may be contained in an amount less than 5 mol% relative to the total diols. If the amount of oligoethylene glycol exceeds 5 mol%, the melting point and crystallization rate of the copolymerized polyester ether may decrease, and coloration due to thermal degradation may occur.

[0022] Copolymerized polyester ether may form a sea-island structure due to phase separation. After melt polymerization, the resin in a molten state at 270°C is drawn through a 13.2 mm diameter nozzle and water-cooled to about 20°C. When the cross section of the resulting pellet is observed with a transmission electron microscope (TEM), the island domain area is preferably 0.1% or more, more preferably 0.2% or more, even more preferably 0.5% or more, and even more preferably 1.0% or more. When the island domain area is within this range, the effect of promoting crystallization through phase separation tends to be obtained. Furthermore, the average domain diameter of the island domains is preferably 20 nm or more, more preferably 30 nm or more, and even more preferably 40 nm or more. When the average domain diameter of the island portions is within this range, the effect of promoting crystallization through phase separation tends to be obtained.

[0023] (Manufacturing method) Known methods can be used to produce the copolymerized polyester ether of the present invention. For example, the target copolymerized polyester ether can be obtained by esterifying 2,5-furandicarboxylic acid and ethylene glycol at 150°C to 220°C, adding polytrimethylene ether glycol and a catalyst, stirring, and polycondensing at 220°C to 280°C while reducing the pressure. Alternatively, the target copolymerized polyester ether can be obtained by polycondensing and transesterifying PEF synthesized by a known method with polytrimethylene glycol at 220°C to 280°C while stirring under reduced pressure. By maintaining a reaction temperature of 220°C or higher, excess diol components can be easily removed, making it easier to obtain a copolymerized polyester ether with a high degree of polymerization. Furthermore, by maintaining a reaction temperature of 280°C or lower, thermal decomposition of the 2,5-furandicarboxylic acid structural unit can be easily suppressed. The use of a catalyst is preferred in synthesizing the copolymerized polyester ether by transesterification of PEF and polytrimethylene glycol. However, if the catalyst used in the production of PEF remains in the PEF while maintaining its catalytic activity, additional catalyst may or may not be added. The copolymerized polyester ether obtained by the above-mentioned melt polymerization / melt reaction may be further subjected to solid-phase polymerization to increase the degree of polymerization.

[0024] The intrinsic viscosity of the copolymerized polyester ether of the present invention is preferably 0.5 to 1.2 dL / g, more preferably 0.6 to 1.0 dL / g, and even more preferably 0.7 to 0.9 dL / g. When the intrinsic viscosity is within this range, molded products with high mechanical strength can be obtained, and a melt viscosity that facilitates melt molding can be obtained.

[0025] The composition of the terminal groups of the copolymerized polyester ether of the present invention is not particularly limited, but it is preferable that it is mainly composed of carboxy terminals and hydroxy terminals, and it is more preferable that the carboxy terminals be 30 eq / ton or less and the hydroxy terminals be 120 eq / ton or less. Terminal groups derived from thermal decomposition during polymerization or from raw materials may include 2-furancarboxylic acid terminals, vinyl terminals, methoxy terminals, etc. Because terminals other than the carboxy terminals and hydroxy terminals affect polymerization properties and coloration during molding, it is preferable that the total amount of terminals other than the carboxy terminals and hydroxy terminals be 50 eq / ton or less.

[0026] The melting point of the copolymerized polyester ether of the present invention is not particularly limited, but is preferably 200° C. or higher, more preferably 205° C. or higher, and even more preferably 210° C. or higher. The melting point of PEF is around 215° C., and as a material with excellent heat resistance, it is preferable that the melting point does not decrease significantly.

[0027] The glass transition temperature of the copolymerized polyester ether of the present invention is not particularly limited, but is preferably not less than 50° C., and more preferably not less than 60° C. If the glass transition temperature is in this range, fluctuations in resin properties due to changes in environmental temperature can be limited to a relatively narrow range.

[0028] The copolymerized polyester ether of the present invention was injected into a mold at 30°C using an injection molding machine, and the resulting product had a total length of 75 mm, a parallel portion length of 30 mm, an end width of 12 mm, a parallel portion center width of 5 mm, and a thickness of The 2 mm dumbbell specimen preferably has a heat of fusion of less than 10 J / g. The resulting dumbbell specimen is subjected to a tensile test at a test speed of 5 mm / min and a chuck distance of 50 mm. The modulus of elasticity is preferably 1500 MPa or more, more preferably 2000 MPa or more. The modulus of elasticity of PEF evaluated under the same conditions is approximately 2500 MPa.

[0029] The copolymerized polyester ether of the present invention has excellent hydrolysis resistance in the presence of enzymes, but also has hydrolysis resistance sufficient for practical use in an environment without enzymes. In a pressure cooker test at a test temperature of 121°C for a test time of 6 hours, the retention of intrinsic viscosity IV is preferably higher than that of PEF, specifically, preferably 70% or more.

[0030] (Additives) Known catalysts can be used when producing copolymerized polyester ethers. For example, acetates or carbonates of lead, zinc, manganese, calcium, cobalt, aluminum, magnesium, sodium, or the like; metal oxides of magnesium, zinc, lead, antimony, germanium, iron, or the like; or organometallic compounds of tin, lead, titanium, or the like can be used alone or in combination depending on the reaction system. Due to concerns about the environmental impact of heavy metals, it is preferable to use non-heavy metals such as aluminum. When using an aluminum catalyst, the aluminum atom content relative to the copolymerized polyester ether is preferably 10 to 500 ppm by mass, more preferably 20 to 200 ppm. A ratio of aluminum atoms relative to the copolymerized polyester ether within this range facilitates achieving sufficient intrinsic viscosity and reduces the amount of aluminum impurities. Furthermore, the use of antimony as a catalyst can sometimes achieve a superior crystallization rate. When using an antimony catalyst, the antimony atom content relative to the copolymerized polyester ether is preferably 50 to 5,000 ppm by mass, more preferably 100 to 1,000 ppm. When the ratio of antimony atoms to the copolymerized polyester ether is within this range, a sufficient intrinsic viscosity is easily obtained, and the thermal decomposition resistance is relatively good and coloration tends to be less likely to occur.

[0031] When producing a copolymerized polyester ether, phosphorus-based and / or thioether-based antioxidants may be used before, during, or after the reaction to suppress thermal and oxidative degradation. These antioxidants may be used alone or in combination. The amount added is preferably 0.1% by mass or more and 5% by mass or less of the thermoplastic copolymerized polyester ether. When the amount added is within this range, the effect of suppressing thermal and oxidative degradation is exhibited and adverse effects on other physical properties tend to be suppressed.

[0032] To further improve physical properties such as crystallization rate and barrier properties, a filler may be added to the copolymerized polyester ether of the present invention. Specific examples of fillers include talc, silica, bentonite, montmorillonite, zeolite, montmorillonite, mica, saponite, hectorite, silica, kaolin, carbon black, carbon nanofiber, metal benzoates, metal stearates, and metal silicates. Furthermore, to improve the decomposition rate in the environment, bio-derived components such as starch, cellulose, other sugars, and proteins can also be added. These can be added alone or in combination of two or more. The amount added is not particularly limited, but is preferably 10% by mass or less of the copolymerized polyester ether.

[0033] (Description of use) The copolymerized polyester ether of the present invention has excellent heat resistance and mechanical properties, and therefore can be used to produce molded articles by known molding methods used for general-purpose plastics. When producing molded articles, the copolymerized polyester ether of the present invention can be used alone, in combination with other resins, or with some additives. Typical examples of molded articles include fibers, films, sheets, bottles, etc. Applications as a substitute for petroleum-derived plastics are particularly promising. [Example]

[0034] Examples and analytical methods are specifically described below, but the present invention is not limited to these examples.

[0035] (Method of producing PEF and PEF-based copolyester ether) Comparative Example 1 A 5L reactor equipped with a stirrer, thermometer, and distillation condenser was charged with 63 parts by weight of 2,5-furandicarboxylic acid (FDCA), 37 parts by weight of ethylene glycol (EG) (EG / FDCA molar ratio 1.5), and 0.3 mol% triethylamine (relative to the furandicarboxylic acid) as a side reaction inhibitor. The esterification reaction was carried out at 170-230 °C for 90 minutes while stirring at 80 rpm, and water and a portion of the ethylene glycol were distilled off. Next, aluminum acetate was added as a catalyst to achieve 30 ppm aluminum relative to the amount of resin produced, and Irgamod 295 (BASF) was added as an antioxidant to achieve 74 ppm phosphorus relative to the amount of resin produced. The temperature was raised from 220 °C to 270 °C over 60 minutes while stirring, while the pressure was slowly reduced. A polycondensation reaction was then carried out at 270 °C for 120 minutes at a pressure of 10 Pa or less until the target stirring torque was reached. It was confirmed that 1200 g of PEF with an intrinsic viscosity of 0.65 dL / g was obtained. 1 H-NMR analysis revealed that the diol contained 2.6 mol% diethylene glycol (DEG) units. The terminal structure was 9 eq / ton of carboxyl terminal, 66 eq / ton of hydroxyl terminal, and 3 eq / ton of 2-furancarboxylic acid terminal.

[0036] Example 1 This was prepared using the same method as the PEF polymerization method described above, so only the differences are described. The amount of EG charged was changed so that the molar ratio of EG / FDCA was 1.8. After the esterification reaction, linear polytrimethylene glycol (PO3G#2000) with a molecular weight of 2000 was added to achieve a PEF / PO3G#2000 ratio of 97 / 3 mass%. The catalyst and antioxidant were added in amounts such that the aluminum atoms were 100 ppm and the phosphorus atoms were 200 ppm relative to the amount of resin produced. The resin obtained after polycondensation had an intrinsic viscosity of 0.72 dL / g, 2.6 mol% DEG and 0.2 mol% PO3G in the diol component, and the terminal configuration was 10 eq / ton of carboxyl terminals, 64 eq / ton of hydroxyl terminals, 3 eq / ton of 2-furancarboxylic acid terminals, and 1 eq / ton of vinyl terminals.

[0037] Example 2 This was prepared using the same method as the PEF polymerization method described above, so only the differences are described. The amount of EG charged was changed so that the molar ratio of EG / FDCA was 1.8. PO3G#2000 was added after the esterification reaction to achieve a PEF / PO3G#2000 ratio of 90 / 10 mass%. The catalyst and antioxidant were added in amounts such that the aluminum atoms were 100 ppm and the phosphorus atoms were 200 ppm relative to the amount of resin produced. The resin obtained after polycondensation had an intrinsic viscosity of 0.80 dL / g, 2.6 mol% DEG and 1.0 mol% PO3G in the diol component, and the terminal configuration was 9 eq / ton of carboxyl terminals, 71 eq / ton of hydroxyl terminals, 3 eq / ton of 2-furancarboxylic acid terminals, and 5 eq / ton of vinyl terminals.

[0038] Example 3 This was prepared using the same method as the PEF polymerization method described above, so only the differences are described. The amount of EG added was changed so that the molar ratio of EG / FDCA was 1.8. PO3G#1000 was added after the esterification reaction to achieve a PEF / PO3G#1000 ratio of 95 / 5% by mass. The catalyst and antioxidant were added in amounts such that the aluminum atoms were 100 ppm and the phosphorus atoms were 200 ppm relative to the amount of resin produced. The resin obtained after polycondensation had an intrinsic viscosity of 0.78 dL / g, and the diol component contained 2.6 mol% DEG and 1.0 mol% PO3G. The terminal structure was 10 eq / ton of carboxyl terminals, 57 eq / ton of hydroxyl terminals, 11 eq / ton of 2-furancarboxylic acid terminals, and 1 eq / ton of vinyl terminals.

[0039] [Evaluation method] (Intrinsic viscosity IV) 0.1 g of a sample was dissolved in 25 mL of a mixed solvent of phenol / tetrachloroethane (mass ratio 6 / 4), and the viscosity was measured at 30°C using an Ubbelohde viscometer.

[0040] (Melting point, heat of fusion, glass transition point) A Hitachi High-Tech Science DSC7020 differential scanning calorimeter was used. 5.0 mg of copolymer polyester ether sample was placed in an aluminum pan, the lid was clamped, and the pan was sealed. The pan was heated from 20°C to 300°C at 10°C / min and held for 2 minutes to completely melt the sample. The pan was then cooled to -50°C at 50°C / min, held for 2 minutes, and then heated again to 300°C at 2°C / min. The melting point and heat of fusion were determined from the endothermic peak of the thermogram obtained during the second heating. The glass transition point was determined as the intersection of a line extending the low-temperature baseline toward the high-temperature side and a tangent drawn at the point where the gradient of the step-like portion of the glass transition curve was maximized.

[0041] (Average domain diameter and occupied area ratio of sea-island structure) A JEOL transmission electron microscope, JEM2100, was used. The sample was a frozen section prepared using a cryomicrotome. It was stained in RuO4 vapor for 30 minutes, then carbon-deposited and observed under the transmission electron microscope. A sea-island structure was observed, so the image was binarized using analysis software, and the average diameter of the circle equivalent to the projected area of ​​the island domains was calculated, along with the area ratio of the island domains.

[0042] (Hydrolysis resistance test) We used a laboratory autoclave, "LSX-500," manufactured by Tomy Seiko Co., Ltd. The autoclave was filled with tap water, sealed, and held at 121°C for 10 hours. The IV retention rate after this was calculated as a measure of hydrolysis resistance. IV retention rate (%)=[(IV1-IV2) / IV1]×100 Here, W1 is the IV of the evaluation sample, and W2 is the IV of the evaluation sample after the hydrolysis test.

[0043] (Diol ratio, terminal group value) The diol ratio and terminal group value are 1 It was determined from the results of H-NMR measurements. 1 The H-NMR measurement conditions were as follows: ND means not detected. Equipment: Fourier transform nuclear magnetic resonance spectrometer (Bruker Japan Co., Ltd., AVANCE NEO 600 model) Measurement solution: 20 mg of sample was dissolved in 0.6 mL of a mixed solvent of deuterated chloroform / deuterated hexafluoroisopropanol (volume ratio 9 / 1), and 10 μL of deuterated pyridine was added to the solution, which was then used for measurement. 1 H resonance frequency: 600.134MHz Detection pulse flip angle: 30° Data acquisition time: 4.0 seconds Delay time: 1.0 seconds Accumulation count: 64 times Measurement temperature: 35℃

[0044] (Adjusting the dumbbell pieces) Amorphous dumbbell pieces were prepared using a DSM 15cc benchtop mixer and a 12cc injection molder according to the following procedure: 10 g of pelletized test sample was loaded into a benchtop mixer heated to 260°C and circulated through the mixer at 100 rpm for 2 minutes. The pellets were then extruded into the barrel of an injection molding machine heated to 260°C and then extruded out of the barrel, filling the mixer and injection molding machine with the test sample. This process was repeated three times, and the test resin was then extruded into the barrel using the same procedure. The resin in the barrel was then injected into a mold heated to (Tg-10)°C using an injection molding machine (load settings: 13.0 bar for 1 second, 5.0 bar for 1 second, and 5.0 bar for 30 seconds). This yielded dumbbell pieces measuring 75 mm in length, 30 mm in length, 12 mm in width at the end, 5 mm in width at the center of the parallel portion, and 2 mm thick.

[0045] (Tensile properties [elastic modulus]) A tensile testing machine "TG-2kN" manufactured by MinebeaMitsumi Inc. was used. The 75 mm length of the dumbbell was set as the tensile direction, and the dumbbell was placed in the tensile testing machine so that the distance between the chucks was 50 mm. The test was then carried out at a tensile speed of 5 mm / min. The slope of the linear increase in stress relative to strain in the elastic region of the strain-stress curve (before the yield point) was calculated as the elastic modulus. The test was carried out twice and the average value was used.

[0046] The evaluation results are shown in Table 1.

[0047] [Table 1]

[0048] The copolyester ethers of Examples 1 to 3 have significantly higher heats of fusion than the PEF of Comparative Example 1, indicating that the polymers of Examples 1 to 3 have higher degrees of crystallinity. Since the crystallinity of polymers produced under the same cooling conditions is higher, it is clear that the crystallization rates of the polymers of Examples 1 to 3 are higher. Furthermore, the copolyester ethers of Examples 1 to 3 show only slight decreases in melting point, glass transition point, and modulus of elasticity compared to the PEF of Comparative Example 1. Because the PEF segments and polytrimethylene glycol segments have low compatibility, a sea-island structure is formed with a sea portion mainly composed of PEF segments and islands mainly composed of polytrimethylene glycol segments, and the volume fraction of the islands is relatively low. Therefore, it is believed that the physical properties such as melting point, glass transition point, and modulus of elasticity remain close to those of the PEF, which is the sea component.

[0049] Comparative Example 2 In the same manner as in Comparative Example 1, a PEF having an intrinsic viscosity of 0.68 dL / g was prepared.

[0050] Example 4 A PEF / PO3G#1000 copolymer having an intrinsic viscosity of 0.70 dL / g was prepared in the same manner as in Example 3. Only the target stirring torque was changed so that an intrinsic viscosity equivalent to that of Comparative Example 2 was obtained.

[0051] (Melt viscosity measurement) The following evaluations were performed using a Toyo Seiki capillary rheometer "Capillograph (registered trademark)." 25 g of a copolymerized polyester ether sample, dried for 65 hours in a vacuum dryer at 70°C, was placed in a barrel heated to 270°C, and pressure was applied with a piston to extrude the molten resin through a capillary (pore diameter 1.0 mm, length 10 mm). The load applied was measured to evaluate the melt viscosity. The shear rate dependency of the melt viscosity was evaluated by changing the piston speed.

[0052] The results of the capillographic evaluation are shown in Figure 1.

[0053] The copolymerized polyester ether of Example 4 corresponds to a PEF of Comparative Example 2 in which 1 mol % of the ethylene glycol constituting the PEF was replaced with polytrimethylene glycol. The copolymerized polyester ether of Example 4 had an intrinsic viscosity of 0.70 dL / g, while the PEF of Comparative Example 2 had an intrinsic viscosity of 0.68 dL / g, meaning that the intrinsic viscosity of Example 4 was slightly higher. Despite this, the melt viscosity of Example 4 was lower across the entire measured range. This indicates that copolymerizing polytrimethylene glycol reduced the melt viscosity and improved fluidity during melting. [Industrial Applicability]

[0054] The rigid copolyester of the present invention has high industrial value because it has excellent moldability due to its improved crystallization rate while maintaining heat resistance equivalent to that of PEF, and can be applied to fibers, films, sheets, bottles, etc.

Claims

1. The copolymer is mainly composed of a dicarboxylic acid component and a diol component, the dicarboxylic acid component is primarily composed of a 2,5-furandicarboxylic acid component, the diol component is primarily composed of an ethylene glycol component and includes a polytrimethylene ether glycol component; Copolymerized polyester ether.

2. 2. The copolymerized polyester ether according to claim 1, wherein the content of the polytrimethylene ether glycol component is 0.1 to 5 mol % based on the total amount of the diol component.

3. 2. The copolymerized polyester ether according to claim 1, wherein the polytrimethylene ether glycol component has a number average molecular weight of 300 to 5,000.

4. The copolymerized polyester ether according to claim 1, which exhibits a sea-island structure when observed with a transmission electron microscope.

5. 5. The copolymerized polyester ether according to claim 4, wherein the area occupied by island domains of the sea-island structure is 0.1% or more and the average diameter of the island domains is 20 nm or more.

6. 2. The copolymerized polyester ether according to claim 1, which has a heat of fusion of 5 J / g or more and 50 J / g or less when melted at 300°C, rapidly cooled to -50°C at a rate of 20°C / min, and then heated again to 300°C at a rate of 2°C / min as measured by a differential scanning calorimeter.

7. 2. The copolymerized polyester ether according to claim 1, which has a glass transition temperature of 50°C or higher when melted at 300°C, rapidly cooled to -50°C at a rate of 20°C / min, and then heated again to 300°C at a rate of 2°C / min, as measured by a differential scanning calorimeter.

8. 2. The copolymerized polyester ether according to claim 1, which has a melting point of 200°C or higher when melted at 300°C, rapidly cooled to -50°C at a rate of 20°C / min, and then heated again to 300°C at a rate of 2°C / min as measured by a differential scanning calorimeter.

9. The copolymerized polyester ether according to claim 1, having an elastic modulus of 1500 MPa or more.

10. A molded article which is mainly composed of the copolymerized polyester ether according to any one of claims 1 to 9 and which is in the form of a fiber, a film, a sheet or a bottle.

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