Polyethylene furanoate, method for producing high-viscosity polyethylene furanoate, polyester composition, polyester bottle, method for producing polyester bottle, and beverage product

Abstract

This polyethylene furanoate has an intrinsic viscosity of 0.95-1.50 dl / g. Said intrinsic viscosity is measured (the Huggins constant is defined as 0.32) at 30°C by using a Ubbelohde viscometer, after dissolving 0.25 g of the polyethylene furanoate in 50 ml of a solvent mixture of phenol / 1,1,2,2-tetrachloroethane=50 / 50 (weight ratio).

Description

[Technical Field]

[0001] The present invention relates to polyethylene furanoate with excellent heat resistance and gas barrier properties that can be produced from biomass-derived raw materials, polyester compositions containing polyethylene furanoate, bottles with excellent heat resistance, gas barrier properties, creep resistance and impact resistance using the same, a method for producing high-viscosity polyester, and a method for producing bottles. [Background technology]

[0002] In recent years, demand for polyester made from plant-derived raw materials has been increasing from an environmental perspective.

[0003] Examples of plant-derived raw materials for polyester include dicarboxylic acids such as succinic acid, glutaric acid, sebacic acid, ferulic acid, caffeic acid, 2,5-franzicarboxylic acid, and ethylene glycol. Examples of diols include ethanediol, propanediol, butanediol, and isosorbite. Among these, 2,5-franzicarboxylic acid is attracting attention as a substitute raw material for terephthalic acid.

[0004] Polyesters using 2,5-franzicarboxylic acid include polybutylene furanoate, polytrimethylene furanoate, Polyethylene furanoate Examples include polyalkylene furanoates, but among them, polyethylene furanoate (PEF) is expected to be a substitute polyester for polyethylene terephthalate (PET), which is used industrially in a variety of applications.

[0005] For example, Patent Document 1 discloses a preform containing polyethylene furanoate for manufacturing plastic containers by stretch blow molding. Specifically, it states that by manufacturing a preform having a viscosity of 0.75 dl / g to 0.9 dl / g and a water content of less than 50 ppm, a container with high mechanical strength and barrier properties can be obtained.

[0006] Furthermore, it is said that an intrinsic viscosity of around 0.7 is appropriate for polyethylene terephthalate containers, and it is known that a viscosity exceeding 0.9 is undesirable because it deteriorates fluidity and moldability (see Patent Document 2). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Special Publication No. 2018-510800 [Patent Document 2] Japanese Patent Publication No. 2000-79633 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, as a result of the inventor's investigation into polyethylene furanoate containers, it was found that polyethylene furanoate has insufficient blow moldability, and blow-molded containers made of polyethylene furanoate have insufficient impact resistance and other properties.

[0009] This invention has been made in view of the problems of the above-mentioned prior art. Specifically, the objective is to provide a polyester that can be manufactured from biomass-derived raw materials and has excellent heat resistance, gas barrier properties, and blow moldability, a polyester composition containing the same, and a bottle using the same that has excellent heat resistance, gas barrier properties, and impact resistance. [Means for solving the problem]

[0010] The present inventors have conducted extensive studies to solve the above problems. As a result, it has been found that the above problems can be solved by using polyethylene furanoate having a specific intrinsic viscosity. Further, it has also been found that the above problems can be solved by using a polyester composition containing polyethylene furanoate and other thermoplastic resins. Furthermore, in a method for producing high-viscosity polyethylene furanoate having a step of producing raw material polyethylene furanoate and a step of solid-phase polymerizing the raw material polyethylene furanoate, the step of producing polyethylene furanoate is carried out using a specific catalyst to obtain raw material polyethylene furanoate having a specific amount of decarboxylated end groups at a specific intrinsic viscosity, and by solid-phase polymerizing this, a high-viscosity polyester that could not be obtained by the conventional method can be obtained, and it has been found that this is effective for solving the above problems.

[0011] That is, the gist of the present invention is as follows. [1] Polyethylene furanoate having an intrinsic viscosity measured by the following method of 0.95 dl / g or more and 1.50 dl / g or less. Dissolve 0.25 g of polyethylene furanoate in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio), and measure at 30°C using an Ubbelohde viscometer. The Huggins constant is 0.32. [2] The polyethylene furanoate according to [1], wherein the polyethylene furanoate contains 1 to 100 ppm of titanium atoms. [3] The polyethylene furanoate according to [1] or [2], which is for blow-molded bottles. [4] A bottle made of polyethylene furanoate having an intrinsic viscosity measured by the following method of 0.75 dl / g or more and 1.2 dl / g or less. Dissolve 0.25 g of the bottle piece in a 50 ml mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio), and measure at 30°C using an Ubbelohde viscometer. The Huggins constant is 0.32. [5] A polyethylene furanoate bottle as described in [4], having a crystallinity of 10% or more and 40% or less, determined by the following formula by the wide-angle X-ray diffraction method. Crystallinity (%) = Peak area of crystalline substance / (Peak area of crystalline substance + Peak area of amorphous substance) × 100 [6] A polyethylene furanoate raw material production step of producing a raw material polyethylene furanoate using a titanium catalyst, and including a solid-phase polymerization step of subjecting the raw material polyethylene furanoate to solid-phase polymerization, The raw material polyethylene furanoate has an intrinsic viscosity of 0.65 dl / g or more and 0.85 dl / g or less measured by the following method, and a decarboxylation end group amount of the following formula of 20 eq / t or less, a method for producing a high-viscosity polyethylene furanoate. Dissolve 0.25 g of raw material polyethylene furanoate in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio), and measure at 30 °C using an Ubbelohde viscometer. The Huggins constant is 0.32

Chemical formula

[10] A polyester composition containing 50% by weight or more of polyethylene furanoate, further containing a crosslinkable thermoplastic resin and / or another thermoplastic polyester resin other than polyethylene furanoate, wherein the other thermoplastic polyester resin has terephthalic acid structural units and structural units selected from 1,4-butanediol structural units and polytetramethylene glycol structural units.

[11] A method for manufacturing a polyester bottle containing polyethylene furanoate, An injection molding process for manufacturing a preform from raw polyester, and The process includes a blow molding step for manufacturing a bottle from the aforementioned preform, A method for producing a polyester bottle, wherein the raw material polyester contains polyethylene furanoate as described in any of [1] to [3].

[12] A method for manufacturing a polyester bottle containing polyethylene furanoate, An injection molding process for manufacturing a preform from raw polyester, and The process includes a blow molding step for manufacturing a bottle from the aforementioned preform, A method for producing a polyester bottle, wherein the raw material polyester is the polyester composition described in

[10] .

[13] A blow-molded bottle which is a molded article of polyethylene furanoate as described in any of [1] to [3], or a polyester composition as described in any of [8] to

[10] .

[14] A blow-molded bottle as described in

[13] , for filling with a carbonated liquid.

[15] A blow-molded bottle as described in

[13] , for filling hot beverages.

[16] A beverage product in which a beverage is filled into a bottle as described in [4] or [5], or a blow-molded bottle as described in any of

[13] to

[15] . [Effects of the Invention]

[0012] The polyethylene furanoate and polyester compositions of the present invention can utilize biomass-derived raw materials, exhibit excellent heat resistance, gas barrier properties, and blow moldability. Therefore, they are particularly suitable for use in blow-molded bottles, enabling the production of lightweight and impact-resistant bottles. They can also be suitably used as polyesters for gas barrier material applications, replacing polyamide-based gas barrier materials. [Brief explanation of the drawing]

[0013] [Figure 1] This graph shows the stroke-stress ratio for Examples A1-A8 and Comparative Example A1. [Modes for carrying out the invention]

[0014] The following describes typical embodiments for carrying out the present invention, but the present invention is not limited to these embodiments unless it exceeds the gist of the invention.

[0015] In this specification, "structural units derived from..." refers to structural units that are incorporated into the polyester polymer derived from the monomer. Hereinafter, "structural units derived from..." will simply be referred to as "units" or "structural units," and for example, "structural units derived from diols" may be referred to as "diol units" or "diol structural units," "structural units derived from dicarboxylic acids" may be referred to as "dicarboxylic acid units" or "dicarboxylic acid structural units," "structural units derived from 2,5-franglicarboxylic acid" may be referred to as "2,5-franglicarboxylic acid units" or "2,5-franglicarboxylic acid structural units," and "structural units derived from 1,2-ethanediols" may be referred to as "1,2-ethanediol units" or "1,2-ethanediol structural units."

[0016] Furthermore, in this specification, the term "principal structural unit" refers to the structural unit that accounts for the largest proportion among the "structural units," and is typically a structural unit that accounts for 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 to 100 mol% of the structural units.

[0017] One embodiment of the present invention is polyethylene furanoate. The polyethylene furanoate of this embodiment is particularly suitable for blow-molded bottle applications. In this embodiment, the polyethylene furanoate uses 2,5-franglionic acid units as the main structural units of all dicarboxylic acid units constituting the polyester, and 1,2-ethanediol structural units as the main structural units of all diol units constituting the polyester.

[0018] [Polyethylene furanoate] The polyethylene furanoate of this embodiment has structural units derived from 2,5-franzicarboxylic acid and 1,2-ethanediol structural units.

[0019] <Dicarboxylic acid structural unit> The polyethylene furanoate of this embodiment contains structural units derived from 2,5-franglicarboxylic acid as dicarboxylic acid structural units. By including structural units derived from 2,5-franglicarboxylic acid, the glass transition temperature is increased, heat resistance is improved, and gas barrier properties are also improved. In the polyethylene furanoate of this embodiment, it is preferable that the structural units derived from 2,5-franglicarboxylic acid are the main dicarboxylic acid units. That is, the structural units derived from 2,5-franglicarboxylic acid are usually contained in an amount of 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 to 100 mol% of the total dicarboxylic acid structural units.

[0020] The polyethylene furanoate of this embodiment may have dicarboxylic acid structural units other than the 2,5-franglianocarboxylic acid unit (also called "other dicarboxylic acids") as dicarboxylic acid units. Examples of other dicarboxylic acids include aliphatic dicarboxylic acids and aromatic dicarboxylic acids. Examples of aliphatic dicarboxylic acids include linear aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dimer acid, and dodecanedioic acid; and cyclic aliphatic dicarboxylic acids such as 1,6-cyclohexanedicarboxylic acid. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and diphenyldicarboxylic acid. Of these dicarboxylic acids, aliphatic dicarboxylic acids are preferred due to their excellent flexibility, and linear aliphatic dicarboxylic acids are more preferred.

[0021] When other dicarboxylic acid structural units are included as dicarboxylic acid structural units, the other dicarboxylic acid structural units included may be only one type, or two or more types may be included in any combination and ratio. When polyethylene furanoate in this embodiment includes other dicarboxylic acid structural units, it is preferable that the content is small in order to easily obtain the above-mentioned effects due to the inclusion of 2,5-furanocarboxylic acid structural units. On the other hand, it is preferable that the content is large in order to have excellent flexibility, etc. Therefore, when other dicarboxylic acid structural units are included, the content is usually 10 mol% or more, preferably 20 mol% or more, and more preferably 30 mol% or more, out of 100 mol% of the total dicarboxylic acid structural units, with the upper limit usually being 50 mol%. Dicarboxylic acid structural units can be introduced into polyethylene furanoate by using dicarboxylic acid components such as dicarboxylic acid, dicarboxylic acid anhydride, lower alkyl esters of dicarboxylic acid (alkyl group with 1 to 4 carbon atoms), and dicarboxylic acid chlorides as raw materials for producing polyethylene furanoate in this embodiment.

[0022] <Diol structural unit> In this embodiment, the diol structural unit includes the 1,2-ethanediol structural unit. By including the 1,2-ethanediol structural unit, the heat resistance and gas barrier properties of the bottle manufactured using polyethylene furanoate are improved. The diol structural unit may include diols other than 1,2-ethanediol (hereinafter also referred to as "other diols") as structural units. Examples of other diols include aliphatic diols other than 1,2-ethanediol (hereinafter also referred to as "other aliphatic diols") and aromatic diols. Examples of other aliphatic diol structural units include 2,2'-oxydiethanol, 2,2'-(ethylenedioxy)diethanol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, triethylene glycol, isosorbide, and the like. Examples of aromatic diols include xylylene glycol, 4,4'-dihydroxybiphenyl, 2,2-bis(4'-hydroxyphenyl)propane, 2,2-bis(4'-β-hydroxyethoxyphenyl)propane, bis(4-hydroxyphenyl)sulfone, and bis(4-β-hydroxyethoxyphenyl)sulfone. In this embodiment, when the polyethylene furanoate contains other diol structural units, the other diols may be just one type, or two or more types may be included in any combination and ratio.

[0023] Of these, from the viewpoint of further improving the heat resistance and gas barrier properties of the bottle, aliphatic diols such as 1,4-butanediol and 1,3-propanediol are preferred as other diols, and 1,4-butanediol is particularly preferred. In this embodiment, it is preferable that the polyethylene furanoate has structural units derived from aliphatic diols as its main diol structural units. That is, from the viewpoint of improving heat resistance and gas barrier properties, it is preferable that the polyethylene furanoate contains aliphatic diol structural units at a concentration of 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and particularly preferably 100 mol% in 100 mol% of the total diol structural units contained in the polyethylene furanoate.

[0024] <Other copolymer components> The polyethylene furanoate of this embodiment may contain structural units derived from copolymer components other than dicarboxylic acids and diols. Examples of other copolymer components include compounds containing three or more functional groups.

[0025] Examples of compounds having three or more functional groups include polyhydric alcohols with three or more functional groups, polycarboxylic acids with three or more functional groups (or their anhydrides, acid chlorides, or lower alkyl esters), hydroxycarboxylic acids with three or more functional groups (or their anhydrides, acid chlorides, or lower alkyl esters), and amines with three or more functional groups.

[0026] Examples of polyhydric alcohols with three or more functionalities include glycerin, trimethylolpropane, and pentaerythritol. These can be used individually or in any combination and ratio of two or more.

[0027] Examples of polycarboxylic acids with three or more functionalities or their anhydrides include trimesic acid, propanetricarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and cyclopentatetracarboxylic anhydride. These may be used individually or in any combination and ratio of two or more.

[0028] Examples of hydroxycarboxylic acids with three or more functionalities include malic acid, hydroxyglutaric acid, hydroxymethylglutaric acid, tartaric acid, citric acid, hydroxyisophthalic acid, and hydroxyterephthalic acid. These may be used individually or in any combination and ratio of two or more.

[0029] In this embodiment, when the polyethylene furanoate contains structural units derived from compounds having three or more functional groups, a high content is preferable in terms of improving strain hardening properties. On the other hand, a low content is preferable in terms of allowing the crosslinking of the polyethylene furanoate in this embodiment to proceed appropriately, making it easier to stably extract strands and resulting in good moldability and mechanical properties. Therefore, the content is usually 5 mol% or less, particularly 4 mol% or less, and especially 3 mol% or less, based on 100 mol% of the total structural units constituting the polyethylene furanoate, and a binary polyester without other copolymer components is most preferable.

[0030] <Chain extender> In the production of polyethylene furanoate according to this embodiment, chain extenders such as carbonate compounds, diisocyanate compounds, dioxazoline, and silicate esters may be used. For example, polyethylene furanoate carbonate can be obtained by using a carbonate compound such as diphenyl carbonate in an amount of preferably 20 mol% or less, more preferably 10 mol% or less, relative to 100 mol% of the total structural units of polyethylene furanoate.

[0031] In this case, the carbonate compound specifically refers to diphenyl carbonate, dito Lil Examples include carbonates, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, ethylene carbonate, diamyl carbonate, and dicyclohexyl carbonate. In addition, carbonate compounds consisting of the same or different hydroxy compounds derived from hydroxy compounds such as phenols and alcohols can also be used.

[0032] Furthermore, specific examples of diisocyanate compounds include known diisocyanates such as 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0033] Examples of silica esters include tetramethoxysilane, dimethoxydiphenylsilane, dimethoxydimethylsilane, and diphenyldihydroxylane. These can be used individually or in any combination and ratio of two or more types.

[0034] <End capping agent> In this embodiment, the end groups of polyethylene furanoate may be encapsulated with carbodiimide, epoxy compounds, monofunctional alcohols, or carboxylic acids. When an end encapsulant is used, its content is preferably 20 mol% or less, and more preferably 10 mol% or less, based on 100 mol% of the total structural units of polyethylene furanoate.

[0035] In this case, examples of carbodiimide compounds used as end-captives include compounds having one or more carbodiimide groups in their molecule (including polycarbodiimide compounds). Specifically, examples of monocarbodiimide compounds include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, di-β-naphthylcarbodiimide, and N,N'-di-2,6-diisopropylphenylcarbodiimide. These can be used individually or in any combination and ratio of two or more types. Furthermore, in the production of polyethylene furanoate according to this embodiment, various additives such as heat stabilizers, antioxidants, hydrolysis inhibitors, crystal nucleating agents, flame retardants, antistatic agents, mold release agents, and ultraviolet absorbers may be used, to the extent that their properties are not impaired, similar to the polyester composition according to this embodiment described later.

[0036] As described above, the polyethylene furanoate of this embodiment may contain structural units other than those derived from 2,5-franzicarboxylic acid and 1,2-ethanediol. However, even in this case, the total amount of structural units derived from 2,5-franzicarboxylic acid and 1,2-ethanediol is preferably 80 mol% or more, and more preferably 90 mol% or more, relative to 100 mol% of the total structural units of the polyethylene furanoate. The raw materials used in the production of polyethylene furanoate in this embodiment may be petroleum-derived or biomass-derived. From the viewpoint of environmental protection, it is preferable to use biomass-derived raw materials, and it is even more preferable to use biomass-derived raw materials as the main structural units. Examples of biomass-derived raw materials include dicarboxylic acid components such as 2,5-franzicarboxylic acid, succinic acid, glutaric acid, adipic acid, and sebacic acid, and diol components such as 1,3-propanediol, 1,4-butanediol, and 1,2-ethanediol.

[0037] <Method for manufacturing polyethylene furanoate> As the method for producing polyethylene furanoate in this embodiment, a known method for producing polyethylene furanoate resin can be used. Furthermore, the reaction conditions in this case can be any appropriate conditions that have been used conventionally, and are not particularly limited.

[0038] Specifically, polyethylene furanoate can be produced by carrying out an esterification or transesterification reaction step using a dicarboxylic acid component with 2,5-franzicarboxylic acid as an essential component, 1,2-ethanediol, and other copolymer components as needed, followed by a polycondensation reaction step. The esterification or transesterification reaction step and the polycondensation reaction step together are also referred to as the polyethylene furanoate raw material production process. Furthermore, the polyethylene furanoate obtained in the polyethylene furanoate raw material production process is sometimes simply called "polyethylene furanoate" or "raw material polyethylene furanoate." During the reaction, the aforementioned chain extenders and end encapsulants may be used as needed. In addition, in terms of increasing the intrinsic viscosity, it is preferable to carry out a solid-phase polymerization step after the polycondensation reaction step in the polyethylene furanoate raw material production process.

[0039] <Esterification or transesterification reaction process> Esterification or transesterification reactions are typically carried out by charging dicarboxylic acid components, diol components, and other copolymer components as needed into a reaction vessel equipped with a stirrer and distillation tubes, and allowing the reaction to proceed while stirring under reduced pressure in an inert gas atmosphere, preferably in the presence of a catalyst, and while distilling off by-products such as water generated by the reaction. The ratio of raw materials used, i.e., the molar ratio of the total diol components to the total dicarboxylic acid components, is usually 1.0 to 3.0 molar times. A higher proportion of diol components is preferable because it allows the esterification reaction to proceed more easily, reduces the number of decarboxylated ends, and makes it easier to obtain polyethylene furanoate with fewer carboxyl ends than hydroxyl ends through polycondensation. On the other hand, a lower proportion of diol components is preferable because it reduces the likelihood of ether structure formation due to side reactions originating from aliphatic diol components. Therefore, the lower limit of this molar ratio is preferably 1.25 molar times, and more preferably 1.30 molar times. On the other hand, the upper limit is preferably 2.5 molar times, and more preferably 2.0 molar times.

[0040] In esterification or transesterification reactions, it is preferable to carry out the reaction in a way that increases the reaction rate of the esterification reaction, specifically by increasing the reaction time at a lower temperature, as this makes it easier to obtain polyethylene furanoates with a low amount of decarboxylated end groups. This allows for a high reaction rate of the esterification reaction and reduces the generation of by-products. The reaction temperature is preferably 160°C or higher, more preferably 170°C or higher, and even more preferably 180°C or higher. On the other hand, it is preferably 230°C or lower, more preferably 220°C or lower, and even more preferably 210°C or lower. By allowing the esterification or transesterification reaction to proceed sufficiently, side reactions such as the decarboxylation of frangic carboxylic acid become less likely to occur, and the subsequent polycondensation and solid-phase polymerization reactions proceed more easily. In addition, the formation of ether structures due to side reactions originating from the diol component becomes less likely, and the heat resistance can be improved. The reaction pressure is usually atmospheric pressure to 10 kPa, but atmospheric pressure is preferred. The reaction atmosphere is usually an inert gas atmosphere such as nitrogen or argon. The reaction time is usually 1 hour or more, with an upper limit of usually 10 hours, preferably 8 hours. The reaction rate can be confirmed by quantifying the unreacted carboxylic acid terminus originating from the frangic carboxylic acid component. The reaction rate at the end of the reaction is preferably 85 mol% or higher, and more preferably 90 mol% or higher.

[0041] <Polycondensation reaction process> The polycondensation reaction is usually carried out under reduced pressure following the esterification or transesterification reaction. Since polycondensation reactions are less likely to produce by-products, it is preferable to start the reduced pressure reaction at a lower temperature. The reaction temperature is preferably above the melting point of the resulting polyethylene furanoate and below the melting point + 100°C. The relationship between the reaction temperature and the melting point of the resulting polyethylene furanoate being within this preferred range can be confirmed by predicting the approximate melting point of the resulting polyethylene furanoate, carrying out the reaction, and then measuring the melting point of the resulting polyethylene furanoate. Specifically, the reaction temperature is preferably 230°C or higher, more preferably 240°C or higher. On the other hand, it is preferably 280°C or lower, and more preferably 270°C or lower. By keeping the reaction temperature within these ranges, the reaction can be carried out at a sufficiently fast rate while minimizing the likelihood of discoloration due to thermal decomposition or side reactions. In particular, the decarboxylation reaction of franzicarboxylic acid is less likely to occur, and the formation of carboxyl terminal groups from hydroxyl terminal groups becomes less likely, which facilitates the subsequent solid-phase polymerization reaction.

[0042] The reaction pressure begins to decrease once a certain temperature is reached. The final pressure is typically 0.01 × 10⁻⁶. 3 Pa or higher, preferably 0.05 × 10 3 It is preferable to set it to Pa or higher. Also, typically 1.4 × 10 3 Pa or less, preferably 0.6 × 10 3 Pa or less, more preferably 0.3 × 10 3 It is preferable to keep the reaction pressure below Pa. Lower reaction pressure allows polymerization to proceed quickly, reducing molecular weight reduction and discoloration due to thermal decomposition of polyethylene furanoate, making it easier to obtain polyethylene furanoate with practically sufficient properties. On the other hand, a higher reaction pressure is preferable because it eliminates the need for expensive equipment. The reaction time is usually between 1 hour and 15 hours. Preferably, it is 10 hours or less, and more preferably 8 hours or less. A longer reaction time allows for sufficient reaction, making it easier to obtain polyethylene furanoate with a high degree of polymerization and excellent mechanical properties. On the other hand, a shorter reaction time makes it less likely for the molecular weight to decrease due to thermal decomposition of polyethylene furanoate, thus making it easier to obtain polyethylene furanoate with excellent mechanical properties. Once the polycondensation reaction is complete, the polyethylene furanoate is generally extracted in a molten state in strand form, cooled, and then cut into pellets.

[0043] <Catalyst> In the polyethylene furanoate raw material manufacturing process, the reaction is preferably carried out in the presence of a titanium catalyst, as this facilitates increasing the viscosity of the polyethylene furanoate by further solid-phase polymerization of the polyethylene furanoate obtained by polycondensation. When using a titanium catalyst, the amount is preferably such that the Ti element concentration in the polyethylene furanoate is 1 to 100 ppm, and more preferably 1 to 50 ppm. Furthermore, the Ti element concentration per mole of raw material dicarboxylic acid component is preferably 0.000001 mole or more, more preferably 0.000002 mole or more, and even more preferably 0.0000038 mole or more. On the other hand, the ratio is preferably 0.00038 or less, more preferably 0.0003 or less, even more preferably 0.00025 or less, and particularly preferably 0.00019 or less. By setting the amount of titanium catalyst within these ranges, polyethylene furanoate can be efficiently produced at a fast polymerization reaction rate while suppressing the decarboxylation reaction of frangic acid. This results in polyethylene furanoate with less discoloration, excellent melt heat stability, and superior hydrolysis properties. Furthermore, high-viscosity polyethylene furanoate can be obtained by further solid-phase polymerization.

[0044] The timing of catalyst addition is not particularly limited; it can be added during raw material preparation or during the manufacturing process. It may also be added in two or more stages, such as during raw material preparation and during the manufacturing process. The titanium compound used as a catalyst is not particularly limited. Tetraalkyl titanates are preferred as titanium compounds. Specifically, examples include tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-t-butyl titanate, tetraoctyl titanate, tetraphenyl titanate, tetracyclohexyl titanate, tetrabenzyl titanate, and mixed titanates thereof. Other examples include titanium(oxy)acetylacetonate, titanium tetraacetylacetonate, titanium(diisoproxy)acetylacetonate, titanium bis(ammonium lactate) dihydroxyl, titanium bis(ethyl acetoacetate) diisopropoxide, titanium(triethanolamine) isopropoxide, polyhydroxytitanium stearate, tetrastearyl titanate, titanium lactate, titanium triethanolamine, and butyl titanate dimer. Furthermore, titanium dioxide and composite oxides containing titanium and silicon are also examples. Among these, tetraisopropyl titanate, tetra-n-butyl titanate, tetraoctyl titanate, titanium(oxy)acetylacetonate, titaniumtetraacetylacetonate, polyhydroxytitanium stearate, tetrastearyl titanate, titanium lactate, butyl titanate dimer, or titania / silica composite oxide are more preferred.

[0045] In addition to the titanium catalyst, metal compounds such as germanium, zirconium, hafnium, antimony, tin, magnesium, calcium, zinc, aluminum, cobalt, lead, cesium, manganese, lithium, potassium, sodium, copper, and barium may also be used. Among these, germanium compounds, magnesium compounds, tin compounds, and zinc compounds are preferred, with magnesium compounds and germanium compounds being particularly preferred. These catalysts may be used individually, or two or more may be used in any combination and ratio. Furthermore, other catalysts may be used in combination, as long as they do not impair the objective of the present invention.

[0046] <Additives> In the polyethylene furanoate raw material manufacturing process, a heat stabilizer may be used. By using a heat stabilizer, thermal decomposition during the polymerization reaction can be suppressed. Known heat stabilizers can be used. Specifically, examples include hindered phenol compounds, hindered amine compounds, and phosphorus compounds. Among these, phosphorus compounds are preferred. Furthermore, in the production of polyethylene terephthalate, such as tetraethylammonium hydroxide, alkali metal compounds, and phosphorus compounds, substances that suppress the by-production of ether components due to side reactions may be used. When using these additives, they may be added during the raw material preparation stage, during intermediate steps in polyethylene furanoate production, or during the extraction stage of the produced polyethylene furanoate. They may also be added to the product after extraction.

[0047] <Intrinsic viscosity> The intrinsic viscosity of the raw polyethylene furanoate after the polycondensation reaction is preferably 0.5 dl / g or higher, more preferably 0.6 dl / g or higher, and particularly preferably 0.65 dl / g or higher. Furthermore, the intrinsic viscosity after the polycondensation reaction is usually 0.85 dl / g or lower. Having the intrinsic viscosity within the above range facilitates the smooth process from extraction to cutting of the polyethylene furanoate after the polycondensation reaction, making it easier to obtain polyethylene furanoate with excellent mechanical properties. Additionally, further solid-phase polymerization after the polycondensation reaction can easily increase the viscosity. The intrinsic viscosity of the raw polyethylene furanoate can be adjusted by the polymerization temperature, polymerization time, and pressure during the polymerization reaction. Furthermore, as described later, further solid-phase polymerization of the raw polyethylene furanoate after the polycondensation reaction can increase its viscosity even more. The intrinsic viscosity of the raw polyethylene furanoate is measured at 30°C using a Uderohde viscous tube. This is achieved by accurately weighing 0.25 g of the raw polyethylene furanoate, adding 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio), and dissolving it in the solution. Here, the Huggins constant is assumed to be 0.32.

[0048] <Terminal group amount> The amount of decarboxylated end groups in the raw material polyethylene furanoate, as shown in the formula below, is preferably 20 eq / t or less, and more preferably 10 eq / t or less. On the other hand, the amount of decarboxylated end groups is usually 0.01 eq / t or more.

[0049] [ka]

[0050] By keeping the amount of decarboxylated end groups in the raw polyethylene furanoate below the specified amount mentioned above, it is easier to achieve even higher viscosity by continuing solid-phase polymerization after the polycondensation reaction. The amount of decarboxylated end groups in the raw polyethylene furanoate can be adjusted by devising the conditions for the esterification or transesterification reaction and the polycondensation reaction, as described above. To reduce the amount of decarboxylated end groups, it is preferable to carry out the esterification or transesterification reaction in a way that increases the reaction rate. Specifically, it is preferable to increase the reaction time at a lower temperature. This makes it possible to increase the reaction rate of the esterification reaction and reduce the amount of by-products. In addition, it is preferable to start the polycondensation reaction at a lower temperature at the beginning of reduced pressure, as this reduces the amount of by-products. Therefore, by checking the amount of decarboxylated end groups in the raw polyethylene furanoate produced by carrying out the esterification or transesterification reaction and the polycondensation reaction under the preferred conditions mentioned above, and selecting the raw polyethylene furanoate with the desired content, it is possible to obtain raw polyethylene furanoate with a decarboxylated end group amount below the specified amount.

[0051] The amount of hydroxyl end groups and carboxyl end groups in the raw material polyethylene furanoate is preferably such that the amount of carboxyl end groups relative to the amount of hydroxyl end groups is less, since the subsequent solid-phase polymerization can proceed more easily. Specifically, the amount of carboxyl end groups relative to the total amount of carboxyl end groups and hydroxyl end groups is preferably 1.0 or less, more preferably 0.9 or less, and even more preferably 0.5 or less. On the other hand, the same ratio is usually 0.01 or more. The relative amounts of hydroxyl end groups and carboxyl end groups can be adjusted by the amounts of the raw material diol component and dicarboxylic acid component charged, the polycondensation temperature, etc., as described above. And, by checking the amount of carboxyl end groups and hydroxyl end groups of the raw material polyethylene furanoate produced in this way and selecting a polyester with a desired relative amount, a raw material polyethylene furanoate with the amount of carboxyl end groups and hydroxyl end groups within a specific range can be obtained.

[0052] The amount of decarboxylated end groups and hydroxyl end groups in the raw material polyethylene furanoate can be quantified by collecting 10 - 20 mg of the raw material polyethylene furanoate, dissolving it in 1 g of a mixed solvent of deuterated chloroform / hexafluoroisopropanol d2 (2 / 1 weight ratio), adding 60 μl of pyridine - d5, and measuring the 1H - NMR of the prepared sample using a 400 MHz nuclear magnetic resonance apparatus manufactured by Brucker. 1 It can be quantified by measuring 1H - NMR. Specifically, 1 By performing 1H - NMR measurement, the amount of decarboxylated end groups and hydroxyl end groups of the raw material polyethylene furanoate can be calculated using the following formula. Amount of decarboxylated end groups (eq / t) = 4d / (182a + 226c) × 10 6 Amount of hydroxyl end groups (eq / t) = 2b / (182a + 226c) × 10 6 In the formula, a represents the integrated value of the peaks of the aliphatic diol structural unit, b represents the integrated value of the peaks of the hydroxyl terminal group, c represents the integrated value of the peaks of the structural unit derived from the aliphatic diol condensate, and d represents the integrated value of the peak of the decarboxylated terminal group. Here, the raw material polyethylene furanoate is 1 In 1H-NMR, peaks for ethylene glycol (aliphatic diol) structural units are observed around 4.6–4.7 ppm, peaks for hydroxyl terminal groups are observed around 3.97–4.0 ppm, peaks for diethylene glycol (a condensate of aliphatic diols) structural units are observed around 3.88–3.9 ppm, and peaks for decarboxylated terminal groups are observed around 6.53–6.5 ppm.

[0053] Furthermore, the amount of carboxyl-terminal groups can be quantified by the following method. First, 0.3 to 0.4 g of the raw material polyethylene furanoate is accurately weighed, and 25 mL of benzyl alcohol is added to it. Stir at 195°C for 7 minutes and visually confirm complete dissolution. Next, cool this solution using an ice bath, add 2 mL of ethanol, and titrate with a 0.01 N NaOH benzyl alcohol solution using a Mitsubishi Chemical Corporation automatic titrator "GT-200". Here, let the titration volume be A ml, and the blank value obtained by the same measurement with only the solvent be B ml. By substituting these values ​​into the following formula, the amount of carboxyl terminal groups can be calculated. Carbonara Kixil Terminal group amount (μeq / g)=(AB)×F×10 / W A [ml]: Measured titer amount B[ml]: Blank titration volume F: Factor of a 0.01N NaOH benzyl alcohol solution W[g]: Sample weight

[0054] The ratio of the amount of decarboxylated end groups to the total amount of decarboxylated end groups and carboxyl end groups (hereinafter sometimes referred to as the "relative amount of decarboxylated end groups") is preferably 0.5 or less, and more preferably 0.3 or less. When the relative amount of decarboxylated end groups in the raw polyethylene furanoate is below the specified value mentioned above, the solid-phase polymerization that follows the polycondensation reaction proceeds more quickly. The relative amount of decarboxylated end groups in the raw polyethylene furanoate can be adjusted by devising the conditions of the esterification or transesterification reaction and the polycondensation reaction, as described above. To reduce the amount of decarboxylated end groups, it is preferable to carry out the esterification or transesterification reaction in a way that increases the reaction rate. Specifically, it is preferable to increase the reaction time at a lower temperature. This makes it possible to increase the reaction rate of the esterification reaction and reduce the amount of by-products. Also, since it reduces the amount of by-products, it is preferable to start the polycondensation reaction at a lower temperature when the reduced pressure is applied. Therefore, by carrying out the esterification or transesterification reaction and the polycondensation reaction under the preferred conditions mentioned above, checking the relative amount of decarboxylated end groups in the produced raw polyethylene furanoate, and selecting the desired relative amount of raw polyethylene furanoate, it is possible to obtain raw polyethylene furanoate in which the relative amount of decarboxylated end groups is below the specified amount.

[0055] <Solid-phase polymerization> As described above, it is preferable to further solid-phase polymerization of the polyethylene furanoate raw material obtained by polycondensation reaction to increase its molecular weight and intrinsic viscosity. The reaction temperature for solid-phase polymerization is not particularly limited as long as it is below the melting point of the polyethylene furanoate resin, but higher temperatures make it easier to increase the molecular weight and intrinsic viscosity of the polyethylene furanoate. Specifically, 80°C or higher is preferred, 100°C or higher is more preferred, and 120°C or higher is even more preferred. On the other hand, the reaction temperature is preferably lower than the reaction temperature of the polycondensation reaction because it makes it less likely for thermal decomposition and side reactions of polyethylene furanoate to occur, the carboxyl group end concentration is low, there is less coloration, and it is easier to obtain high molecular weight polyester.

[0056] The method of solid-phase polymerization is not particularly limited, but examples include heating pelletized or powdered polyethylene furanoate raw materials under an inert gas atmosphere or under reduced pressure. The reaction may be carried out with the pellets or powder standing still or with stirring. If stirring is required, stirring may be done using a stirring blade installed in the reaction vessel or by moving the reaction vessel. The reaction time is usually 0.5 hours or more, preferably 1 hour or more, and more preferably 2 hours or more. On the other hand, a reaction time of 60 hours or less is preferred, more preferably 50 hours or less, and even more preferably 45 hours or less. A longer reaction time tends to result in polyethylene furanoate with a higher molecular weight, leading to superior mechanical properties. Conversely, a shorter reaction time tends to reduce the likelihood of discoloration of the polyethylene furanoate.

[0057] <Method for manufacturing high-viscosity polyester> As described above, the polyethylene furanoate of this embodiment preferably has a high intrinsic viscosity, and is particularly preferably 0.95 dl / g or higher. Such a high-viscosity polyethylene furanoate can be obtained by solid-phase polymerization of the raw material polyethylene furanoate obtained by the polycondensation reaction described above (hereinafter, the polyester after this solid-phase polymerization may be referred to as "high molecular weight polyethylene furanoate" or "high viscosity polyethylene furanoate"). In particular, by using polyethylene furanoate produced using a titanium catalyst as the raw material, having an intrinsic viscosity of 0.65 dl / g or more and 0.85 dl / g or less, and the aforementioned decarboxylated end group content of 20 eq / t or less, and then performing solid-phase polymerization, a high-viscosity polyethylene furanoate that could not be obtained conventionally can be obtained (hereinafter, the method for producing this high-viscosity polyethylene furanoate after solid-phase polymerization may be referred to as "the method for producing high-viscosity polyethylene furanoate of this embodiment").

[0058] In other words, the method for producing high-viscosity polyethylene furanoate according to this embodiment comprises a polyethylene furanoate raw material production step in which raw polyethylene furanoate is produced using a titanium catalyst, and a solid-phase polymerization step in which the raw polyethylene furanoate is solid-phase polymerized, wherein polyethylene furanoate having an intrinsic viscosity of 0.65 dl / g or more and 0.85 dl / g or less and a decarboxylated end group content of 20 eq / t or less is solid-phase polymerized. Furthermore, as mentioned above, in order to obtain high-viscosity polyethylene furanoate by solid-phase polymerization, it is preferable that the relative amount of decarboxylase end groups in the raw polyethylene furanoate is a specific amount. Therefore, in the method for producing high-viscosity polyethylene furanoate of this embodiment, it is preferable to use polyethylene furanoate in which the relative amount of decarboxylase end groups is a specific amount as described above as the raw polyethylene furanoate.

[0059] The method for producing high-viscosity polyethylene furanoate according to this embodiment comprises an esterification or transesterification reaction step of 2,5-franzicarboxylic acid component and 1,2-ethanediol, a polycondensation reaction step, and a solid-phase polymerization step. The inventors have found that by using a titanium catalyst in the polycondensation reaction step and adjusting the conditions of the esterification or transesterification reaction and the polycondensation reaction to control the amount of decarboxylated end groups within a specific range, it is possible to obtain polyethylene furanoate with a high intrinsic viscosity that could not be obtained by conventional methods, and that this is effective in solving the aforementioned problems. In other words, we have found that the above-mentioned problems can be solved by a method for producing high-viscosity polyethylene furanoate, comprising a raw material production step for producing a raw material polyethylene furanoate having structural units derived from 2,5-franzicarboxylic acid and structural units derived from 1,2-ethanediol, and a solid-phase polymerization step for solid-phase polymerization of the raw material polyethylene furanoate, wherein the raw material production step is carried out using a titanium catalyst, and the raw material polyethylene furanoate used in the solid-phase polymerization step has an intrinsic viscosity measured by the following method of 0.65 dl / g or more and 0.85 dl / g or less, and a decarboxylated end group content of 20 eq / t or less.

[0060] A high intrinsic viscosity of the raw polyethylene furanoate is preferable in that it facilitates obtaining the desired high-viscosity polyethylene furanoate through short-time solid-phase polymerization. However, a low viscosity is preferable in that it facilitates obtaining raw polyethylene furanoate with excellent color tone, low amounts of carboxylic acid and decarboxylated ends through short-time polycondensation reactions, and allows subsequent solid-phase polymerization to proceed quickly. Specifically, it is preferably 0.65 dl / g or higher, and more preferably 0.67 dl / g or higher, while on the other hand, it is preferably 0.85 dl / g or lower, and more preferably 0.83 dl / g or lower.

[0061] As mentioned above, in order to obtain high-viscosity polyethylene furanoate by solid-phase polymerization, it is preferable that the raw polyethylene furanoate has a small amount of decarboxylated end groups produced by the decarboxylation reaction of franciocarboxylic acid. Specifically, polyester with a decarboxylated end group content of 20 eq / t or less, preferably 10 eq / t or less, is used. By keeping the amount of decarboxylated end groups in the raw polyethylene furanoate below a specific amount, the molecular weight increase by solid-phase polymerization proceeds smoothly, and the viscosity of the polyethylene furanoate can be sufficiently increased. The method for producing raw polyethylene furanoate with a decarboxylated end group content below a specific amount is as described above.

[0062] Furthermore, using a raw polyethylene furanoate with fewer carboxyl-terminal groups than hydroxyl-terminal groups is preferable because it accelerates the solid-phase polymerization. The amount of carboxyl-terminal groups in the raw polyethylene furanoate is 5 eq / t or more, preferably 10 eq / t or more, and 60 eq / t or less, preferably 50 eq / t or less. Here, the amount of hydroxyl-terminal groups is 30 eq / t or more, preferably 40 eq / t or more, and 120 eq / t or less, preferably 100 eq / t or less. The method for producing a raw polyethylene furanoate that satisfies these terminal group ratios is as described above.

[0063] In particular, when obtaining polyethylene furanoate with high intrinsic viscosity, it is preferable to perform precrystallization before solid-phase polymerization. Specifically, the molecular weight of polyethylene furanoate increases by performing solid-phase polymerization at a temperature of about 190 to 210°C, but in the process of reaching this temperature range, it is preferable to gradually increase the temperature from about 100°C. Here, it is particularly preferable to heat at 120°C for about 1 to 6 hours to crystallize the polyethylene furanoate. By allowing sufficient time for such precrystallization, fusion of pellets or particles is less likely to occur, and the subsequent solid-phase polymerization reaction can proceed smoothly. If fusion occurs during precrystallization, it is preferable to remove and untangle them as appropriate.

[0064] <Intrinsic viscosity> As described above, the method for producing high-viscosity polyethylene furanoate according to this embodiment makes it possible to produce polyethylene furanoate with a high intrinsic viscosity that could not be obtained conventionally. Therefore, the polyethylene furanoate in this embodiment is preferably a high-viscosity polyethylene furanoate with an intrinsic viscosity of 0.95 dl / g or more. The intrinsic viscosity of the high-viscosity polyethylene furanoate is preferably greater than 0.95 dl / g, more preferably 1.0 dl / g or more, even more preferably greater than 1.00 dl / g, and most preferably 1.1 dl / g or more. It is also preferably 1.5 dl / g or less, and more preferably 1.3 dl / g or less. In other words, the intrinsic viscosity of the polyethylene furanoate in this embodiment is preferably 0.95 dl / g or more and 1.5 dl / g or less. By setting the intrinsic viscosity within this range, it is possible to obtain polyethylene furanoate with excellent stretch moldability and blow moldability. Furthermore, as will be described later, when the polyethylene furanoate of this embodiment is used in combination with other thermoplastic resins, a high intrinsic viscosity is preferable because it facilitates the improvement of oxygen barrier properties. Because the intrinsic viscosity is within the above-mentioned range, it becomes easier to obtain molded products with excellent strain hardening properties, minimal thickness variation, and good impact resistance. In particular, it becomes easier to obtain molded articles with excellent impact resistance when filled with liquids that are subjected to internal pressure, such as carbonated liquids. Furthermore, because thickness variation is minimal and uniform thin films can be formed, using the polyethylene furanoate of this embodiment makes it possible to lighten bottles and reduce the environmental impact. Moreover, it is easy to extrude without applying high pressure during molding.

[0065] The reason why polyethylene furanoates exhibit strain hardening easily due to their high intrinsic viscosity is presumed to be as follows: Strain hardening is a phenomenon in which the viscosity of a resin increases significantly more than its linear viscosity, depending on the stretching speed. Normally, in a stretching process, stress concentrates in areas with low thickness, leading to deformation and an increase in thickness unevenness. However, polymers with strain hardening properties tend to have a more uniform thickness even after stretching because the viscosity increases in the thinner areas, making them suitable for stretch molding processes.

[0066] <Strain-hardening properties> Strain hardening properties can be quantified by the stress difference measured by a tensile test described later. The stress difference of polyethylene furanoate in this embodiment is 5 N / mm 2 The above is preferable, 8 N / mm 2 The above is more preferable. On the other hand, the stress difference is 50 N / mm 2 The following is preferable: 40 N / mm 2 More preferably, the following: 30 N / mm 2 The following is even more preferable: By keeping the stress difference within the above range, strain hardening properties are exhibited, making it possible to obtain bottles of uniform thickness by blow molding. Here, strain hardening properties can be adjusted by the polymerization temperature, polymerization time, and pressure during the polymerization reaction when manufacturing polyethylene furanoate. The strain hardening properties of the polyethylene furanoate in this embodiment can be adjusted in the same manner as the method for adjusting the intrinsic viscosity of polyethylene furanoate described above.

[0067] <Glass transition temperature (Tg)> In this embodiment, the glass transition temperature of polyethylene furanoate is preferably 50°C or higher and 150°C or lower. More preferably, the glass transition temperature is 60°C or higher. On the other hand, it is even more preferably 130°C or lower. Because the glass transition temperature of polyethylene furanoate is within the above range, deformation due to the pressure difference between the inside and outside of the bottle is less likely to occur, even if the contents of the bottle are effervescent substances such as carbonated water, and the bottle is less likely to deform even when stored in a high-temperature environment. The glass transition temperature of the polyethylene furanoate in this embodiment can be adjusted by selecting other types of aliphatic diol components, etc. The glass transition temperature can be measured using a differential scanning calorimetry device according to the method specified in JIS K7121-1987. Specifically, polyethylene furanoate is heated from 25°C to 30°C above its melting point and up to 60°C, then cooled back down to 25°C, and then heated again to 30°C above its melting point and up to 60°C. The heating and cooling rates are set at 10°C / min. The glass transition temperature at the midpoint of this second heating cycle is defined as the glass transition temperature.

[0068] <Decarboxylated end group amount> The amount of decarboxylated end groups contained in the polyethylene furanoate of this embodiment is preferably small, as this facilitates obtaining high-viscosity polyethylene furanoate by solid-phase polymerization. Specifically, it is preferably 20 eq / t or less, and more preferably 10 eq / t or less. On the other hand, the amount of decarboxylated end groups is usually 0.01 eq / t or more. The method for adjusting the amount of decarboxylated end groups in the polyethylene furanoate before solid-phase polymerization is as described above. Furthermore, the amount of decarboxylated end groups in the polyethylene furanoate obtained by solid-phase polymerization can be adjusted by the amount of decarboxylated end groups contained in the raw polyethylene furanoate before solid-phase polymerization, etc.

[0069] [Polyester composition] Another embodiment of the present invention is a polyester composition containing the polyethylene furanoate of this embodiment described above (hereinafter sometimes referred to as "the polyester composition of this embodiment"). The polyester composition of this embodiment preferably contains the polyethylene furanoate of this embodiment and another thermoplastic resin (hereinafter sometimes referred to as "other thermoplastic resin"). By including the polyethylene furanoate of this embodiment and another thermoplastic resin, the strain-curing properties are improved, and stretch molding can be easily performed.

[0070] <Other thermoplastic resins> Other thermoplastic resins are thermoplastic resins other than the polyethylene furanoate of this embodiment described above. Examples of other thermoplastic resins include other thermoplastic polyester resins other than the polyethylene furanoate of this embodiment (hereinafter sometimes referred to as "other polyesters"), crosslinkable thermoplastic resins, acrylics, polycarbonates, etc. Of these, at least one of other polyesters and crosslinkable thermoplastic resins is preferable in terms of excellent strain-curing properties.

[0071] In this embodiment, the polyester composition is preferably composed of a large amount of the polyester of this embodiment in terms of excellent gas barrier properties and blow moldability, while on the other hand, it is preferable that it contains a large amount of other polyesters in terms of excellent strain hardening properties and creep resistance. These other thermoplastic resins may be used individually, or two or more may be used in any combination and ratio.

[0072] <Other polyesters> Other polyesters are polyesters having structural units derived from diols and structural units derived from dicarboxylic acids, and are polyesters other than the polyethylene furanoate of this embodiment described above. Examples of dicarboxylic acids that constitute the dicarboxylic acid units of other polyesters include o-phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, and decamethylene. JiExamples include carboxylic acids, their anhydrides, and lower alkyl esters. For other polyesters, it is preferable that structural units derived from dicarboxylic acids other than these 2,5-franzicarboxylic acid units are the main dicarboxylic acid units. It is particularly preferable that the dicarboxylic acid units include terephthalic acid units.

[0073] On the other hand, diols that constitute the diol units of other polyesters include, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), and 1,2-hex Examples include linear diols such as sandiol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, and polytetramethylene glycol; and aliphatic diols such as cyclic diols such as 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2,2-bis(4-hydroxycyclohexyl)propane, and alkylene oxide adducts of 2,2-bis(4-hydroxycyclohexyl)propane. Of these, the other polyesters preferably have structural units derived from aliphatic diols as diol units, and more preferably have structural units derived from aliphatic linear diols.

[0074] <Crosslinkable thermoplastic resin> Strain-curing properties can also be improved by using a crosslinkable thermoplastic resin having functional groups that can react with carboxyl groups and hydroxyl groups contained in the polyester composition. Examples of functional groups that can react with carboxyl groups and hydroxyl groups include epoxy groups, oxazoline groups, carboxyl groups, and carbodiimide groups. These functional groups are preferably located in the side chains of the thermoplastic resin. The presence of these functional groups in the side chains forms a branched structure, which slows down the relaxation of molecules in response to stretching during stretch molding, thereby improving strain-curing properties.

[0075] <Composition mainly composed of polyester according to this embodiment> In particular, for compositions with excellent gas barrier properties and blow moldability, it is preferable that the polyethylene furanoate of this embodiment is present in a larger amount than other thermoplastic resins. That is, the polyester composition of this embodiment is preferably a polyester composition containing 50% by weight or more of polyethylene furanoate, and also containing thermoplastic resins other than polyethylene furanoate. In the polyester composition of this embodiment, it is preferable that the polyethylene furanoate of this embodiment constitutes the largest proportion. Specifically, the content of polyethylene furanoate of this embodiment in the polyester composition is usually 50% by weight or more, preferably 55% by weight or more, more preferably 60% by weight or more, even more preferably 65% ​​by weight or more, and particularly preferably 70% by weight or more. The upper limit for the content of polyethylene furanoate of this embodiment is 100% by weight, but in terms of the ease with which the effects of including other components can be expressed, it is preferable that it be 99% by weight or less, more preferably 95% by weight or less, and even more preferably 90% by weight or less. In other words, in this case, the content of other thermoplastic resins in the polyester composition of this embodiment is preferably 1% by weight or more, more preferably 5% by weight or more, even more preferably 10% by weight or more, while on the other hand, it is preferably 50% by weight or less, more preferably 45% by weight or less, even more preferably 40% by weight or less, and particularly preferably 30% by weight or less. Furthermore, when the other thermoplastic resin is polyester, the content is particularly preferably 1% by weight to 30% by weight, and even more preferably 5% by weight to 30% by weight.

[0076] Furthermore, if the composition containing a large amount of polyethylene furanoate of this embodiment also contains other thermoplastic resins, the other thermoplastic resin is preferably a crosslinkable thermoplastic resin or a polyester having at least one of the structural units of 1,4-butanediol units and polytetramethylene glycol units as diol units. The latter polyester is particularly preferably having 1,4-butanediol units, and even more preferably having both 1,4-butanediol units and polytetramethylene glycol units. In other words, the polyester composition of this embodiment preferably contains a large amount of polyethylene furanoate of this embodiment, and further contains a crosslinkable thermoplastic resin and / or another thermoplastic polyester resin other than polyethylene furanoate of this embodiment, wherein the other thermoplastic polyester resin is a polyester having terephthalic acid units as dicarboxylic acid units and at least one of the structural units of 1,4-butanediol units and polytetramethylene glycol units as diol units, and it is more preferable that the polyester of this embodiment is included in 50% by weight or more.

[0077] In this embodiment, when a crosslinkable thermoplastic resin is included in a composition containing a large amount of polyester, a large amount is preferable in terms of excellent strain-curing properties. On the other hand, a small amount is preferable in terms of reducing the likelihood of gel formation and lumps, and thus increasing the yield. Specifically, the amount of crosslinkable thermoplastic resin is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, and even more preferably 0.1% by weight. On the other hand, it is preferably 20% by weight or less, more preferably 10% by weight or less, and even more preferably 5% by weight or less.

[0078] Thus, the polyester composition of this embodiment, when used in combination with the polyethylene furanoate of this embodiment and other polyesters, can exhibit sufficient strain-hardening properties even when the intrinsic viscosity and glass transition temperature of the polyester of this embodiment described above are outside the preferred range.

[0079] <Compositions mainly composed of other thermoplastic resins> In particular, for compositions with excellent strain-curing properties and creep resistance, it is preferable that the other thermoplastic resin is present in a larger proportion than the polyethylene furanoate of this embodiment. That is, it is preferable that the polyester composition of this embodiment contains the other thermoplastic resin in the largest proportion. Specifically, the content of the other thermoplastic resin in the polyester composition is usually 50% by weight or more, preferably 70% by weight or more, and more preferably 80% by weight or more. On the other hand, in this case, the content of the other thermoplastic resin is preferably 99% by weight or less, and more preferably 95% by weight or less. In particular, when the other thermoplastic resin is polyethylene terephthalate, the content of polyethylene terephthalate is preferably 80% to 99% by weight.

[0080] The other thermoplastic resins included in large quantities in this composition are preferably polyester resins, and more preferably polyethylene terephthalate (PET) and polybutylene terephthalate, due to their excellent strain-curing and stretch-molding properties. Polyethylene terephthalate is particularly preferred because it easily improves the creep resistance of blow-molded bottles, and polybutylene terephthalate is particularly preferred because it easily improves strain-curing properties.

[0081] The polyethylene furanoate of this embodiment, included in small amounts in this composition, preferably has a particularly high intrinsic viscosity, as this facilitates the improvement of gas barrier properties when used in combination. Furthermore, it is preferable that the glass transition temperature is within the aforementioned preferred range. Specifically, the polyethylene furanoate of this embodiment, included in small amounts, is a polyester having structural units derived from 2,5-franzicarboxylic acid and structural units derived from aliphatic diols, and preferably has an intrinsic viscosity of 0.95 dl / g or more and 1.50 dl / g or less, and more preferably has a glass transition temperature of 50°C or more and 150°C or less.

[0082] In other words, another embodiment of the present invention is a polyester composition containing polyethylene furanoate having an intrinsic viscosity of 0.95 dl / g or more and 1.50 dl / g or less, and other thermoplastic resins. Preferably, such a polyester composition contains 1 to 20% by weight of the polyethylene furanoate and further contains polyethylene terephthalate.

[0083] <Additives> In the manufacture of polyester compositions, various additives such as heat stabilizers, antioxidants, hydrolysis inhibitors, crystal nucleating agents, flame retardants, antistatic agents, mold release agents, and ultraviolet absorbers may be used, to the extent that their properties are not impaired.

[0084] These additives may be added to the reactor before the polymerization reaction of polyester, to the conveying equipment, etc., from the start to the end of the polymerization reaction, or to the product after the polymerization reaction is complete and before extraction. They may also be added to the product after extraction. Furthermore, when molding the polyester composition, in addition to the various additives mentioned above, impact modifiers, nucleating agents, reinforcing agents, bulking agents, etc., may be added during molding. When using additives, one type may be used alone, or two or more types may be used in any combination and ratio.

[0085] <Impact-resistant modifier> The polyester composition of this embodiment may contain an impact-resistant modifier. By including an impact-resistant modifier, the mechanical properties can be improved. When an impact-resistant modifier is included, the content is preferably 0.01% by weight or more and 10% by weight or less. Examples of impact-resistant modifiers include butadiene-based rubber, acrylic-based rubber, and silicone-acrylic composite rubber. Among these, core-shell type impact-resistant modifiers such as Metabrane (manufactured by Mitsubishi Chemical Corporation) and Kaneace (manufactured by Kaneka Corporation) are preferably used.

[0086] Fillers may be used in the manufacture of polyester compositions. The fillers may be inorganic or organic. The amount of filler in the polyester composition should be selected within a range that sufficiently provides the effect of the filler while maintaining the tensile elongation and impact resistance of the polyester composition. Examples of inorganic fillers include anhydrous silica, mica, talc, titanium dioxide, calcium carbonate, diatomaceous earth, allophane, bentonite, potassium titanate, zeolite, sepiolite, smectite, kaolin, kaolinite, glass, limestone, carbon, wollastonite, calcined perlite, silicates such as calcium silicate and sodium silicate, hydroxides such as aluminum oxide, magnesium carbonate, and calcium hydroxide, and salts such as ferric carbonate, zinc oxide, iron oxide, aluminum phosphate, and barium sulfate.

[0087] In the case of a polyester composition containing an inorganic filler, the content in the polyester composition is usually 1% by weight or more, preferably 3% by weight or more, and more preferably 5% by weight or more. Also, it is usually 80% by weight or less, preferably 70% by weight or less, and more preferably 60% by weight or less.

[0088] Examples of organic fillers include raw starch, modified starch, pulp, chitin / chitosan, coconut shell powder, bamboo powder, tree bark powder, and powders of kenaf and straw. Nanofiber cellulose, obtained by defibrating fibers such as pulp to the nanoscale, is also an example.

[0089] In the case of a polyester composition containing an organic filler, the content in the polyester composition is usually 0.1% by weight or more, preferably 1% by weight or more. Also, it is usually 70% by weight or less, preferably 50% by weight or less.

[0090] Examples of nucleating agents include glass fibers, carbon fibers, titanium whiskers, mica, talc, boron nitride, CaCO3, TiO2, silica, layered silicates, polyethylene wax, and polypropylene wax. Talc, boron nitride, silica, layered silicates, polyethylene wax, and polypropylene wax are preferred, with talc being the most preferred.

[0091] Furthermore, inorganic fillers added to improve rigidity and organic stabilizers added as heat stabilizers may also contribute to promoting crystallization. In addition, inorganic or organic foreign substances mixed in during the polyester manufacturing or molding process can also act as crystal nucleating agents. Therefore, as used herein, a crystal nucleating agent refers to particles that are solid at room temperature and contribute to promoting crystallization.

[0092] The particle size of the nucleating agent is preferably small. Preferably, the particle size of the nucleating agent is 5 μm or less, more preferably 3 μm or less, even more preferably 1 μm or less, and most preferably 0.5 μm or less. The lower limit of the particle size of the nucleating agent is usually 0.1 μm.

[0093] When a nucleating agent is used in the production of a polyester composition, the amount is preferably 0.001% by weight or more, more preferably 0.01% by weight or more, and even more preferably 0.1% by weight or more, relative to the polyester composition. The upper limit of the amount of nucleating agent is preferably 30% by weight, more preferably 10% by weight, even more preferably 5% by weight, and particularly preferably 1% by weight, relative to the polyester. By setting the amount of nucleating agent within the above range, the crystallization-promoting effect is easily exhibited, and the mechanical properties and flexibility of the polyester composition tend to be obtained as well.

[0094] <Method for producing polyester composition> The polyester composition of this embodiment can be manufactured using known methods. For example, it can be manufactured by melt-kneading each raw material using a single-screw or twin-screw extruder or a Banbari mixer to form pellets.

[0095] <Strain-hardening properties> The strain-hardening properties of the polyester composition of this embodiment can also be quantified by the stress difference measured by a tensile test described later, similar to the case of the polyethylene furanoate of this embodiment described above. The preferred range of the stress difference and the reason for it are the same as described above for the polyethylene furanoate of this embodiment. That is, the stress difference is 5 N / mm 2 The above is preferable, 8 N / mm 2 The above is more preferable. On the other hand, the stress difference is 50 N / mm 2 below It is preferable that there be 40 N / mm 2 More preferably, the following: 30 N / mm 2 The following is even more preferable. By keeping the stress difference within the above range, strain-curing properties are exhibited, making it possible to obtain bottles of uniform thickness by blow molding. Here, strain-curing properties can be adjusted by the type (especially the intrinsic viscosity) and amount of polyester contained in the polyester composition, the polymerization temperature during the production of each polyester, the polymerization time, the pressure during the polymerization reaction, etc. The strain-curing properties of the polyester composition of this embodiment are particularly enhanced by the combined use of the polyethylene furanoate of this embodiment with other thermoplastic resins. It can be adjusted to a desirable range.

[0096] [Method for confirming composition] The composition of polyethylene furanoate and polyester compositions can be determined by conventionally known methods. For example, the composition can be separated into its constituent components by HPLC (high-performance liquid chromatography), and then each component can be analyzed by methods such as NMR (nuclear magnetic resonance spectroscopy) or GC / MS (gas chromatography-mass spectrometry) after methanol decomposition.

[0097] [Manufacturing method for polyester bottles] The polyethylene furanoate and polyester compositions according to the above embodiment can be suitably used in the manufacture of blow-molded bottles and preforms for blow-molded bottles. There are no particular limitations on the method for manufacturing blow-molded bottles and preforms for blow-molded bottles, but an example is shown below.

[0098] The production of a polyester bottle containing polyethylene furanoate comprises an injection molding step for producing a preform from raw polyester, and a blow molding step for producing a bottle from the preform. Here, it is preferable that the raw polyester contains the polyethylene furanoate of the above-described embodiment. This production method can also be suitably used when the raw polyester is the polyester composition of the above-described embodiment.

[0099] The bottle is manufactured by first melt-kneading a polyethylene furanoate or polyester composition, along with other additives as needed, using a single-screw or twin-screw extruder or a Banbari mixer to form pellets, or by directly melt-kneading during injection molding, then injecting the molten material into a mold, cooling, and removing it to form a preform. When other thermoplastic resins are added, it is preferable to pelletize them to ensure thorough mixing. The resin temperature in this extrusion process is not particularly limited, but is usually in the range of 210 to 290°C, and more preferably 230 to 270°C, from the viewpoint of moldability and suppression of thermal degradation.

[0100] Next, in the blow molding process, the preform is placed into a mold of the desired shape, which has been heated to a predetermined temperature by a heater, and then compressed air is blown in to attach it to the mold, thereby forming the bottle.

[0101] The heating temperature of the preform is preferably 90°C to 150°C, more preferably 100°C to 140°C, and particularly preferably 110°C to 130°C. By heating the preform within the above range and blowing in high-pressure air, the thickness of the bottle can be made uniform during blow molding.

[0102] [Polyester bottle] By using the polyethylene furanoate and polyester composition according to this embodiment, a high-viscosity polyester bottle (hereinafter sometimes referred to as "high-viscosity bottle according to this embodiment") can be obtained.

[0103] The intrinsic viscosity of the high-viscosity bottle according to this embodiment is preferably high in terms of impact resistance, and preferably low in terms of ease of forming a bottle of the desired shape. Specifically, it is preferably 0.75 dl / g or more, more preferably 0.85 dl / g or more, even more preferably 0.90 dl / g or more, and particularly preferably 0.92 dl / g or more. On the other hand, it is preferably 1.2 dl / g or less, and more preferably 1.15 dl / g or less. Here, the intrinsic viscosity of the bottle is measured at 30°C using an Ubbelohde viscometer after dissolving 0.25 g of bottle material in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio). Here, the Huggins constant is assumed to be 0.32.

[0104] In this embodiment, the degree of crystallinity of the high-viscosity bottle is preferably high in terms of creep resistance, and preferably low in terms of transparency. Specifically, it is preferably 10% or more, more preferably 15% or more, preferably 40% or less, and more preferably 30% or less. Here, the degree of crystallinity can be determined by measuring wide-angle X-ray diffraction and using the following formula. Crystallinity (%) = Crystalline peak area / (Crystalline peak area + Amorphous peak area) × 100

[0105] By using the polyethylene furanoate and polyester composition according to this embodiment, a bottle can be obtained that exhibits excellent strain hardening properties, minimal thickness variations, and good creep and impact resistance. The blow-molded bottle produced using the polyethylene furanoate and polyester composition according to this embodiment is suitable for use as a beverage bottle for alcoholic beverages, carbonated beverages, hot beverages, etc., due to its excellent gas barrier properties, creep resistance, and impact resistance. In other words, a beverage product can be manufactured by filling the bottle (blow-molded bottle) according to this embodiment with a beverage.

[0106] Blow-molded bottles can be made into various shapes depending on the shape of the mold used. The shape of a blow-molded bottle is not particularly limited; any shape that can hold a beverage is acceptable. In particular, by molding it into an appropriate shape with a uniform and sufficiently thick wall thickness, it is suitable for carbonated beverages such as beer and champagne, and hot beverages such as tea and coffee.

[0107] When these liquids are filled into bottles, the bottle opening is usually sealed with a resin cap or the like, resulting in a higher internal pressure compared to the external pressure. Therefore, in order to pack, transport, and display the bottles in stores while they are in an upright position under this high internal pressure, it is preferable to make the bottom of the bottle a pressure-resistant shape that suppresses deformation due to the internal pressure. Since deformation of the bottle bottom and body is generally accompanied by creep (irreversible deformation due to continuous stress), there are common wall thicknesses and shapes suitable for these bottles. Therefore, bottles used for filling carbonated liquids or hot beverages may be referred to as "heat-resistant pressure bottles" below. In other words, the polyethylene furanoate and polyester composition of this embodiment are suitable for heat-resistant pressure bottles.

[0108] The pressure-resistant shape of the bottom of a heat-resistant bottle can be, for example, a petal-shaped (petaloid) shape, a dome shape facing inward (a so-called champagne bottom shape), or a shape with an uneven surface in the center of the bottom. A thicker average wall thickness makes it less likely for the bottle to deform or burst due to internal pressure. Specifically, although it depends on the internal pressure, the average wall thickness of the bottle body is preferably 0.20 mm or more, more preferably 0.25 mm or more, and even more preferably 0.30 mm or more. On the other hand, from the viewpoint of bottle moldability, the average wall thickness is preferably 0.70 mm or less.

[0109] By using the polyethylene furanoate and polyester composition according to this embodiment, it is possible to obtain a lightweight heat-resistant pressure-resistant bottle by reducing the unevenness of the wall thickness and enabling the creation of a uniform thin film. Specifically, the weight / contents ratio of the bottle is preferably 10 g / L or more, more preferably 20 g / L or more, even more preferably 30 g / L or more, and particularly preferably 50 g / L or more, while on the other hand, it is preferably 200 g / L or less, more preferably 150 g / L or less, and particularly preferably 120 g / L or less.

[0110] Furthermore, by using the polyethylene furanoate and polyester composition according to this embodiment, a uniform thin-walled bottle with excellent gas barrier properties can be obtained. Therefore, the polyethylene furanoate and polyester composition according to this embodiment is particularly suitable for bottles filled with carbonated liquids such as carbonated beverages. In addition, blow-molded bottles manufactured using the polyethylene furanoate and polyester composition according to this embodiment exhibit excellent creep resistance and impact resistance when filled with carbonated liquids. Specifically, it is preferred as a bottle for filling liquids containing 1 to 10 GV of carbon dioxide, more preferably as a bottle for filling liquids containing 1 to 5 GV of carbon dioxide, even more preferably as a bottle for filling liquids containing 1 to 3 GV of carbon dioxide, and particularly preferred as a bottle for filling liquids containing 1 to 2 GV of carbon dioxide.

[0111] The polyethylene furanoate and polyester composition according to this embodiment exhibits excellent oxygen barrier properties. Therefore, when used in blow-molded bottles, it is suitable for alcoholic beverages such as wine bottles. In particular, because it has superior gas barrier properties compared to conventional PET bottles for alcoholic beverages, it can be used without a diamond-like carbon coating. Polyethylene furanoate according to this embodiment, having a glass transition temperature of 50°C or higher, is less prone to deformation due to pressure differences inside and outside the bottle, making it suitable for bottles used to fill effervescent substances such as carbonated beverages. Furthermore, because it is less prone to deformation even when stored in high-temperature environments, it is suitable for bottles used for hot beverages.

[0112] [Biaxially oriented film] The polyethylene furanoate and polyester compositions according to the embodiments of the present invention described above can be suitably used as biaxially oriented films. There are no particular limitations on the method of manufacturing them, but an example is shown below.

[0113] First, a polyethylene furanoate or polyester composition is used, and the molten sheet extruded from the die is cooled and solidified on a cooling roll to obtain an unstretched sheet. In this case, it is necessary to improve the adhesion between the sheet and the rotating cooling drum in order to improve the flatness of the sheet, and electrostatic application adhesion and / or liquid coating adhesion methods are preferably employed. Next, the obtained unstretched sheet is stretched in two axial directions. In this case, first, the unstretched sheet is stretched in one direction using a roll or tenter type stretcher. The stretching temperature is usually 80 to 140°C, preferably 85 to 120°C, and the stretching ratio is usually 2.5 to 7 times, preferably 3.0 to 6 times. Then, the stretching temperature perpendicular to the first stretching direction is usually 70 to 170°C, and the stretching ratio is usually 3.0 to 7 times, preferably 3.5 to 6 times. Then, the film is heat-treated at a temperature of 180-270°C under tension or under relaxation of 30% or less to obtain a biaxially oriented film. In stretching, a method of stretching in one direction in two or more stages can also be employed. In that case, it is preferable to ensure that the final stretching ratios in both directions are within the above ranges.

[0114] Furthermore, simultaneous biaxial stretching can also be employed in the production of biaxially oriented films. Simultaneous biaxial stretching is a method of simultaneously stretching the aforementioned unstretched sheet in two directions under temperature control, typically at 70-120°C, preferably 80-110°C. The stretching ratio is preferably 4-50 times, more preferably 7-35 times, and even more preferably 10-25 times, in terms of area ratio. Subsequently, heat treatment is performed at a temperature of 170-250°C under tension or under relaxation of 30% or less to obtain a stretched and oriented film. Regarding the simultaneous biaxial stretching apparatus employing the above stretching method, conventionally known stretching methods such as screw type, pantograph type, and linear drive type can be employed.

[0115] When applying a primer treatment or hard coat treatment to the film surface during the stretching process of the biaxially oriented film described above, known as in-line coating, a coating solution for forming a primer layer or hard coat layer should be applied to the sheet after uniaxial stretching. When a primer or hard coat layer is provided on the film by the coating method, coating can be done simultaneously with stretching, and the thickness of the coating layer can be reduced according to the stretching ratio, making it possible to manufacture a film suitable as a biaxially oriented film. [Examples]

[0116] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the invention.

[0117] The evaluation methods in the following examples and comparative examples are as follows.

[0118] (1) Intrinsic viscosity of polyester 0.25 g of polyester was accurately weighed and dissolved in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio). The solution was measured at 30°C using a Uderohde viscous tube. The Huggins constant was set to 0.32.

[0119] (2) Glass transition temperature of polyester The glass transition temperature was measured using a differential scanning calorimetry system "DSC7000x" (manufactured by Hitachi High-Tech Science Corporation) according to the method of JIS K7121-1987. Specifically, the polyester was heated from 25°C to 260°C, then cooled to 25°C, and then heated again to 260°C. The heating and cooling rates were set to 10°C / min. The glass transition temperature at the midpoint during this second heating cycle was defined as the glass transition temperature.

[0120] (3) End base weight of polyester The amounts of decarboxylated end groups and hydroxyl end groups in polyester were determined by taking 20 mg of polyester, dissolving it in 1 g of a mixed solvent of deuterated chloroform / hexafluoroisopropanol d2 (2 / 1 by weight ratio), and then adding 560 μl of pyridine-d. This prepared sample was then analyzed using a 400 MHz nuclear magnetic resonance spectrometer manufactured by Brucker. 1 The result was quantified by measuring H-NMR. in particular, 1 By performing 1H-NMR measurements, the amount of decarboxylated end groups and hydroxyl end groups of the polyester was calculated using the following formula. Decarboxylation terminal group amount (eq / t)=4d / (182a+226c)×10 6 Hydroxyl terminal group weight (eq / t) = 2b / (182a + 226c) × 10 6

[0121] In the formula, a represents the integrated value of the peaks of the ethylene glycol structural unit, b represents the integrated value of the peaks of the hydroxyl terminal group, c represents the integrated value of the peaks of the diethylene glycol structural unit, and d represents the integrated value of the peaks of the decarboxylated terminal group. 1 In 1H-NMR, peaks for ethylene glycol were observed around 4.6–4.7 ppm, peaks for hydroxyl terminal groups around 3.97–4.0 ppm, peaks for diethylene glycol around 3.88–3.9 ppm, and peaks for decarboxylated terminal groups around 6.53–6.5 ppm.

[0122] Furthermore, the amount of carboxyl-terminated groups was quantified by the following method. First, 0.3-0.4 g of polyester was accurately weighed, and 25 mL of benzyl alcohol was added to it. The mixture was stirred at 195°C for 7 minutes, and complete dissolution was confirmed visually. Next, after cooling this solution using an ice bath, 2 mL of ethanol was added, and the solution was titrated using a 0.01 N NaOH benzyl alcohol solution with a Mitsubishi Chemical Analytec Co., Ltd. automatic titrator "GT-200". Here, the titration volume was denoted as A ml, and the blank value obtained by the same measurement using only the solvent was denoted as B ml. The amount of carboxyl-terminated groups was calculated by substituting these values ​​into the following formula. Carbonara Kixil Terminal group amount (μeq / g)=(AB)×F×10 / W A [ml]: Measured titer amount B[ml]: Blank titration volume F: Factor of a 0.01N NaOH benzyl alcohol solution W[g]: Sample weight

[0123] (4) Stress difference (strain hardening) obtained by tensile testing Tensile tests were conducted under the following conditions based on JIS K7127. The stress difference was defined as the difference between the stress at 100% elongation and the maximum stress. A stress difference of 5 N / mm 2 The above conditions were considered satisfactory. Equipment: AG-1000ARI (manufactured by Shimadzu Corporation) Sample size: 15mm wide x 70mm long x 200μm thick Stretching temperature: 90℃ Chuck spacing: 30mm Distance between gauge lines: 30mm Tensile speed: 200 mm / min Tensile distance: 160mm

[0124] (5) Blow moldability The blow-molding performance of bottle preforms was evaluated based on the yield (molding success rate) when blow-molded using a blow molding machine (FRB-1, manufactured by Frontier Corporation). A yield of 100% was marked with ○, and a yield of less than 95% was marked with ×.

[0125] (6) Gas barrier properties (oxygen permeability) The oxygen permeability of blow-molded bottles was measured using an oxygen permeability measuring device (OX-TRAN2 / 21, manufactured by MODERNCONTROL). The oxygen permeability was measured under conditions of 23°C and 90% RH, with 12 hours of conditioning from the start of measurement, and the value was recorded 72 hours after the start of measurement. The oxygen gas barrier performance was evaluated relative to the oxygen permeability of a general-purpose PET bottle (100% polyester (G) bottle obtained in Reference Example 3 described later), with the value set to 1. A relative evaluation of 1 or higher was considered good. A relative evaluation of 5 or higher is particularly desirable because it eliminates the need for the diamond-like carbon coating applied to conventional PET bottles to improve gas barrier performance in order to ensure oxygen barrier performance for wine bottle applications.

[0126] (7) Creep resistance Blow-molded bottles were filled with 2.8 GV carbonated water, capped, and heated in 40°C water for 1 hour. After the samples returned to room temperature, the bottle dimensions (total height: height from top to bottom of bottle, body diameter: circumference of the widest part of the bottle, volume: volume of the bottle) were measured. A rate of change of less than that of a general-purpose PET bottle was marked with ◎, equal to or equal to ○, and greater than or equal to ×. Note that 1 GV is a unit that indicates the state in which 1 L of liquid contains 1 L of dissolved carbon dioxide under standard conditions.

[0127] (8) Impact resistance test <Water filling> Distilled water was filled into blow-molded bottles, capped, and cooled to 5°C. These bottles were then dropped three times consecutively from a height of 80 cm in an upright position (cap side up). A similar sample was then dropped three times consecutively in an inverted position (cap side down). After the test, a circle (○) indicated no leakage of the contents, a triangle (△) indicated deformation of the bottle, and a cross (×) indicated leakage. <Carbonated water filling> Bottles whose creep resistance had been evaluated were cooled to 5°C, and a drop test was conducted in the same manner as for bottles filled with water to evaluate their impact resistance.

[0128] (9) Reaction rate of the esterification reaction The reaction rate in the esterification reaction is determined by taking a sample of the reaction solution immediately before reducing the pressure (before the polycondensation step begins) and using this sample. 1 The results were determined by analysis using 1H-NMR. Specifically, 10-20 mg of the reaction solution was taken, dissolved in 1 g of dimethyl sulfoxide-d6, and measured using a Bruker 400 MHz NMR spectrometer.

[0129] (10) Degree of crystallinity of the bottle Wide-angle X-ray diffraction was measured, and the degree of crystallinity was calculated. Wide-angle X-ray diffraction was performed using a "NANO-Viewer" (manufactured by Rigaku Corporation) with a CuKα X-ray source (λ=0.154 nm), a camera length of 74.7 mm, an irradiation time of 45 minutes, and a temperature of 25°C. The profile obtained from the wide-angle X-ray diffraction measurement was fitted, and the degree of crystallinity was determined using the following formula. Crystallinity (%) = Crystalline peak area / (Crystalline peak area + Amorphous peak area) × 100

[0130] [Reference example 1] In a reaction vessel equipped with a stirrer, nitrogen inlet, heater, thermometer, and vacuum port, 85.7g of 2,5-franzicarboxylic acid (manufactured by V&V PHARMA INDUSTRIES), 68.16g of 1,2-ethanediol (manufactured by Mitsubishi Chemical), and 0.029g of a 35% by weight aqueous solution of tetraethylammonium hydroxide were charged as raw materials, and the inside of the reaction vessel was subjected to a nitrogen atmosphere. Next, the reaction vessel was immersed in an oil bath set to 120°C, and the temperature was raised to 210°C over 60 minutes while stirring. The mixture was then held at 210°C for 200 minutes, and the distillate was collected to allow the esterification reaction to proceed. A portion of the reaction solution was taken and analyzed using NMR, which revealed that the esterification reaction rate was 92%.

[0131] Next, to the reaction solution after the esterification reaction, 0.71 g of a 1,2-ethanediol solution containing 5.0% by weight of tetrabutyl titanate was added (the molar ratio of Ti to 2,5-franzicarboxylic acid was 0.00019 mol). 、The resulting polyester was heated to 260°C over 1.5 hours, and the pressure was gradually reduced from atmospheric pressure to approximately 130 Pa over 1.5 hours, after which it was maintained at 130 Pa. After 3 hours and 46 minutes from the start, stirring was stopped, and the polycondensation reaction was terminated by restoring pressure. The produced polyester was extracted in strand form from the bottom of the reaction vessel, cooled through a cooling water bath, and then cut with a pelletizer to obtain polyester(I) in pellet form approximately 2-3 mm square. The intrinsic viscosity of polyester(I) was 0.78 dL / g. The end group amounts were 23 eq / t for carboxyl end groups, 71 eq / t for hydroxyl end groups, and 4 eq / t for decarboxyl end groups. The ratio of the amount of decarboxyl end groups to the total amount of decarboxyl end groups and carboxyl end groups was 0.14.

[0132] [Reference example 2] Polyester (J) was obtained in the same manner as in Reference Example 1, except that the holding time at 210°C in the esterification reaction was changed from 200 minutes to 75 minutes. Here, the esterification reaction rate was 83%. The intrinsic viscosity of polyester (J) was 0.81 dL / g, and its end group amounts were 19 eq / t for carboxyl end groups, 38 eq / t for hydroxyl end groups, and 29 eq / t for decarboxyl end groups. The ratio of the amount of decarboxyl end groups to the total amount of decarboxyl end groups and carboxyl end groups was 0.60. The results of Reference Examples 1 and 2 are summarized in Table 1.

[0133] [Table 1]

[0134] Table 1 confirms that by carrying out the esterification reaction over a long period of time, sufficient esterification can be achieved, resulting in polyethylene furanoate with a reduced number of decarbonized end groups.

[0135] [Example A1] <Melting polymerization> In a reaction vessel equipped with a stirrer, nitrogen inlet, heater, thermometer, and rectification column, 42.85 kg of 2,5-franzicarboxylic acid (manufactured by V&V PHARMA INDUSTRIES), 30.6 L of 1,2-ethanediol (manufactured by Mitsubishi Chemical), and 14.3 g of a 35 wt% aqueous solution of tetraethylammonium hydroxide were charged as raw materials, and the inside of the reaction vessel was subjected to a nitrogen atmosphere. Next, the mixture was heated to 200°C over 2 hours while stirring, and then held at 200°C for 2 hours and 30 minutes to collect the distillate and allow the esterification reaction to proceed (total heating time: 4 hours and 30 minutes). Next, this reaction mixture was transferred to a reactor equipped with a vacuum port and a stirrer, and 888.5 g of a 1,2-ethanediol solution containing 2.0 wt% tetrabutyl titanate was added and stirring was started (the molar ratio of Ti to 2,5-franzicarboxylic acid was 0.00019 mol, and the Ti concentration in the resulting polyester was 50 ppm). The temperature was raised to 260°C over 2 hours, and the pressure was gradually reduced from atmospheric pressure to approximately 130 Pa over 1.5 hours, and then maintained at 130 Pa. After 3 hours and 50 minutes from the start of the reduced pressure, stirring was stopped, and the pressure was restored to terminate the polycondensation reaction. The produced polyester was extracted in strand form from the bottom of the reaction vessel, cooled through a cooling water bath, and then cut with a pelletizer to obtain polyester (A) in pellet form approximately 2-3 mm square. The intrinsic viscosity of polyester (A) was 0.74 dL / g. Furthermore, the end group weights were 29 eq / t for carboxyl end groups, 51 eq / t for hydroxyl end groups, and 5 eq / t for decarboxyl end groups, with the ratio of decarboxyl end groups to the total amount of decarboxyl end groups and carboxyl end groups being 0.14.

[0136] <Solid-phase polymerization> Precrystallization was performed on polyester (A) by heating while introducing nitrogen gas at a flow rate of 30 L / min. Specifically, 10 kg of polyester (A) was placed in an inert oven (Yamato Scientific Co., Ltd. "DN411I"), heated at 120°C for 3 hours, then cooled to room temperature (25°C) and the fused pellets were separated. These pellets were then heated again at 150°C for 3 hours, cooled to room temperature (25°C), and the fused pellets were separated once more. Next, 10 kg of the pre-crystallized polyester (A) was placed in the aforementioned inert oven, and solid-phase polymerization was carried out by heating it at 120°C for 1 hour, 150°C for 1 hour, 180°C for 3 hours, and 200°C for 18 hours while nitrogen gas was introduced at a flow rate of 30 L / min, thereby obtaining polyester (B). The intrinsic viscosity of polyester (B) was 1.02 dL / g, and the glass transition temperature was 81.2°C.

[0137] The strain-hardening properties of polyester (B) were evaluated by performing a tensile test. Specifically, a metal frame (SUS304, outer diameter 110 mm, inner diameter 70 mm, thickness 0.2 mm) with surface release treatment was placed on a 150 mm x 150 mm PTFE tape (NAFRONT TAPE® BTOMBO No. 9001, manufactured by Nichias Corporation, thickness 0.05 mm). 2.0 g of polyester (B) was measured and placed inside this metal frame, and another 150 mm x 150 mm PTFE tape was placed on top of it. With the polyester (B) sandwiched between two iron plates (160 mm x 160 mm, thickness 3 mm), a 70 mm x 70 mm x 0.2 mm thick heat-pressed sheet was obtained by heat pressing using a heat press machine (IMC-180C, manufactured by Imoto Seisakusho Co., Ltd.). The hot press temperature was 280°C, and the hot press time was 1 minute of preheating followed by 1 minute of pressing.

[0138] The PEFE tape was peeled off the obtained hot-pressed sheet and evaluated by tensile testing. As shown in Table 2, it exhibited good strain-hardening properties. Since its strain-hardening properties were comparable to those of polyesters (C) and (D) described later, it is considered suitable for blow molding.

[0139] [Example A2] In Example A1, the process was carried out in the same manner as in Example A1, except that the final heating time at 200°C during solid-phase polymerization was changed from 18 hours to 24 hours. Polyester (C) with an intrinsic viscosity of 1.12 dl / g, a decarboxylated end group content of 8 eq / t, and a glass transition temperature of 82.6°C was obtained. A hot-pressed sheet was prepared from the obtained polyester (C) in the same manner as in Example A1, and a tensile test was performed. As shown in Table 2, it exhibited good strain-hardening properties. Furthermore, the blow-molding properties of polyester (C) were good, as described in Example B1 below.

[0140] [Example A3] In Example A1, the process was carried out in the same manner as in Example A1, except that the final heating time at 200°C during solid-phase polymerization was changed from 18 hours to 40 hours. Polyester (D) with an intrinsic viscosity of 1.23 dl / g and a glass transition temperature of 83.1°C was obtained. A hot-pressed sheet was prepared from the obtained polyester (D) in the same manner as in Example A1, and a tensile test was performed. As shown in Table 2, it exhibited good strain-hardening properties. Furthermore, the blow-molding properties of polyester (D) were good, as described in Example B2 below.

[0141] [Comparative Example A1] For Example A1, a hot-pressed sheet was prepared in the same manner as in Example A1, except that polyester (A) was used instead of polyester (B), and a tensile test was performed. As a result, as shown in Table 2, the strain hardening properties were insufficient. Furthermore, as shown in Comparative Example B1 described later, it was confirmed that it was unsuitable for blow molding.

[0142] [Example A4] Using a small kneader (Xplore series MC15 manufactured by Xplore instruments), 11.25 g of polyester (A) and 3.75 g of polyester (E) shown below were supplied from a hopper as raw materials. After kneading at a rotation speed of 100 rpm, 240°C, and under a nitrogen atmosphere for 5 minutes, the kneaded resin was recovered from the purge hole to obtain strands of polyester composition. A hot-pressed sheet was manufactured by hot-pressing the obtained polyester composition strands in the same manner as in Example A1, except that the hot-pressing temperature was set to 260°C. Tensile tests were performed on the obtained hot-pressed sheet. As shown in Table 2, it exhibited good strain-hardening properties. • Polyester (E): Manufactured by Mitsubishi Engineering Plastics Corporation, product name "NOVADURAN 5020," a homopolyester resin of terephthalic acid and 1,4-butanediol.

[0143] [Examples A5-A8] Regarding Example A4, a polyester composition was obtained in the same manner as in Example A4, except that the resin formulation was changed to the formulation shown in Table 2, and a heat-pressed sheet was manufactured therefor. heat Tensile tests were conducted on the press sheets. As shown in Table 2, all of them exhibited good strain hardening properties. Therefore, they are presumed to be suitable for blow molding. Details of the resins shown in the table are provided below. • Polyester (F): Manufactured by Mitsubishi Engineering Plastics Corporation, product name "NOVADURAN 5505S," a copolymer polyester resin of terephthalic acid, 1,4-butanediol, and polytetramethylene glycol (PTMG). • Crosslinkable thermoplastic resin (A): NOF Corporation, product name "Marproof G-0250SF", epoxy group-containing acrylic-styrene polymer. Mw: 20,000, Tg: 74℃, epoxy equivalent: 310 g / eq. • Crosslinkable thermoplastic resin (B): Nippon Shokubai Co., Ltd. Product name "Epocross RPS-1005" Oxazoline group modified polystyrene.

[0144] The results for Examples A1 to A8 and Comparative Example A1 are summarized in Table 2.

[0145] [Table 2]

[0146] The following was found from the results summarized in Table 2. A comparison of Examples A1-A3 and Comparative Example A1 confirmed that polyethylene furanoate, which has structural units derived from 2,5-franzicarboxylic acid and structural units derived from 1,2-ethanediol and has high intrinsic viscosity, exhibits excellent strain hardening properties, can be made thin and uniform by blow molding or stretching, and is suitable for blow-molded bottles and biaxially oriented films. Furthermore, a comparison of Examples A4 to A8 with Comparative Example A1 confirmed that polyethylene furanoate having structural units derived from 2,5-franzicarboxylic acid and structural units derived from 1,2-ethanediol significantly improves strain hardening properties when used in combination with a small amount of other thermoplastic resins, allowing it to be made thin and uniform by blow molding or stretching, and thus proving suitable for blow-molded bottles and biaxially oriented films. Furthermore, the ease with which the polyester and polyester composition of this embodiment can be molded into thin, uniform pieces is presumed to be due to the fact that the higher the intrinsic viscosity of the polyester, the higher its strain-hardening properties, as shown in Figure 1.

[0147] Furthermore, Figure 1 shows the results of measuring the stroke-stress of these polyesters. Figure 1 was measured under the same conditions as the stress difference measurement by the tensile test described above. From Figure 1, it was found that polyesters with high intrinsic viscosity show a rise in stress with stretching, making them suitable for stretching. Similarly, compositions using other thermoplastic resins also showed a rise in stress, indicating that they are also suitable for stretching.

[0148] [Comparative example A2] <Melting polymerization> In a reaction vessel equipped with a stirrer, nitrogen inlet, heater, thermometer, and rectification column, 42.85 kg of 2,5-franzicarboxylic acid, 30.6 L of 1,2-ethanediol, and 14.3 g of a 35 wt% aqueous solution of tetraethylammonium hydroxide were charged as raw materials, and the reaction vessel was subjected to a nitrogen atmosphere. Next, the temperature was raised to 210°C over 2 hours while stirring, and held at 210°C for 30 minutes, after which the distillate was collected to allow the esterification reaction to proceed (total heating time: 2 hours 30 minutes). Next, the reaction mixture was transferred to a reactor equipped with a vacuum port and a stirrer, and 888.5 g of a 1,2-ethanediol solution containing 2.0% by weight of tetrabutyl titanate (the molar ratio of Ti to 2,5-franzicarboxylic acid was 0.00019 moles) was added and stirring was started (the Ti concentration relative to the resulting polyester was 50 ppm). The temperature was raised to 260°C over 1.5 hours, and the pressure was gradually reduced from atmospheric pressure to approximately 130 Pa over 1.5 hours, and then maintained at 130 Pa. After 2 hours and 47 minutes from the start of the reduced pressure, stirring was stopped, and the pressure was restored to terminate the polycondensation reaction. The produced polyester was extracted in strand form from the bottom of the reaction vessel, cooled through a cooling water bath, and then cut with a pelletizer to obtain polyester (a) in pellet form approximately 2-3 mm square. The intrinsic viscosity of polyester (a) was 0.61 dL / g. Furthermore, the amounts of terminal groups were 21 eq / t for carboxyl terminal groups, 58 eq / t for hydroxyl terminal groups, and 34 eq / t for decarboxyl terminal groups. The ratio of the amount of decarboxyl terminal groups to the total amount of decarboxyl terminal groups and carboxyl terminal groups was 0.61.

[0149] [Comparative example A3] Polyester (b) was obtained by precrystallization and solid-phase polymerization in the same manner as in Example A1, except that polyester (a) was used instead of polyester (A). The intrinsic viscosity of polyester (b) was 0.73 dL / g, and the amount of decarboxylated end groups was 42 eq / t.

[0150] [Comparative example A4] For Comparative Example A3, the procedure was the same as for Comparative Example A3, except that the final heating time at 200°C during solid-phase polymerization was changed from 18 hours to 24 hours, to obtain polyester (c) with an intrinsic viscosity of 0.74 dl / g.

[0151] [Comparative Example A5] For Comparative Example A3, the procedure was the same as for Comparative Example A3, except that the final heating time at 200°C during solid-phase polymerization was changed from 18 hours to 36 hours, to obtain polyester (d) with an intrinsic viscosity of 0.76 dl / g.

[0152] The reaction conditions, intrinsic viscosity, and end group content for Examples A1-A3, Comparative Examples A3-A5, and Comparative Example B3 (described later) are summarized in Tables 3-1 to 3-3.

[0153] [Table 3-1]

[0154] [Table 3-2]

[0155] [Table 3-3]

[0156] The results summarized in Tables 3-1 to 3-3 confirm that by carrying out the esterification reaction at low temperatures over a long period of time, esterification proceeds sufficiently, and by performing a polycondensation reaction using a titanium catalyst, a polyester with a reduced amount of decarbonized end groups can be obtained. Furthermore, by solid-phase polymerization of this polyester, a high-viscosity polyester can be obtained.

[0157] [Example B1] A bottle preform was manufactured using polyester (C) as the raw material. The obtained preform was blow-molded using a blow molding machine (FRB-1, manufactured by Frontier Co., Ltd.) to obtain a blow-molded bottle with a capacity of 350 ml, a weight of 29 g, a weight / capacity ratio of 82 g / L, an average wall thickness of 0.26 mm, and a petaloid-shaped base. The yield during blow molding was 100%. The obtained bottle had an intrinsic viscosity of 0.92 dl / g and a crystallinity of 16%. Furthermore, due to its petaloid-shaped base, the obtained bottle was suitable for carbonated liquids and hot beverages, exhibiting high oxygen barrier properties, excellent creep resistance, and impact resistance.

[0158] [Example B2] A blow-molded bottle (heat-resistant bottle) was obtained in the same manner as in Example B1, except that polyester (D) was used as the raw material instead of polyester (C). The yield during blow molding was 100%. The obtained bottle had an intrinsic viscosity of 0.99 dl / g and a crystallinity of 19%. Furthermore, the obtained bottle had high oxygen barrier properties and excellent impact resistance. In addition, its creep resistance was superior to that of general-purpose PET bottles.

[0159] [Examples B3-B7] A blow-molded bottle (heat-resistant pressure bottle) was obtained in the same manner as in Example B1, except that the proportions of the raw material polyester were as shown in Table 4. The yield during blow molding was 100%. The obtained bottle has oxygen barrier properties similar to general-purpose PET. bottle It was comparable to, and had superior impact resistance. Furthermore, its creep resistance was better than that of general-purpose PET bottles. • Polyester (G): Polyethylene terephthalate manufactured by Mitsubishi Chemical Corporation, product name "Novapex BK2180", with an intrinsic viscosity of 0.83 dl / g.

[0160] [Example B8] A blow-molded bottle (heat-resistant bottle) was obtained in the same manner as in Example B1, except that polyester (B) was used as the raw material instead of polyester (C). The yield during blow molding was 100%. Furthermore, the obtained bottle had superior impact resistance compared to Comparative Examples B1 and B2, which will be described later. In addition, its creep resistance was also superior to that of general-purpose PET bottles.

[0161] [Comparative Example B1] A blow-molded bottle was obtained in the same manner as in Example B1, except that polyester (A) was used as the raw material instead of polyester (C). The yield during blow molding was less than 95%. Furthermore, the obtained bottle had poor impact resistance and creep resistance.

[0162] [Comparative example B2] Polyester (H) with an intrinsic viscosity of 0.85 dl / g was obtained in the same manner as in Example A1, except that the final heating time at 200°C during solid-phase polymerization was changed from 18 hours to 6 hours. A blow-molded bottle was obtained in the same manner as in Example B1, except that polyester (H) was used as the raw material instead of polyester (C). The yield during blow molding was 100%. However, the resulting bottle had poor impact resistance and creep resistance.

[0163] [Comparative Example B3] Polyester (K) with an intrinsic viscosity of 0.92 dl / g was obtained in the same manner as in Example A1, except that the final heating time at 200°C during solid-phase polymerization was changed from 18 hours to 9 hours. A blow-molded bottle was obtained in the same manner as in Example B1, except that polyester (K) was used as the raw material instead of polyester (C). The yield during blow molding was 100%. However, the resulting bottle had poor impact resistance.

[0164] [Comparative example B4] A blow-molded bottle (heat-resistant bottle) was obtained in the same manner as in Example B1, except that the proportion of raw material polyester was as shown in Table 4. The yield during blow molding was 100%. However, the obtained bottle had poor impact resistance and creep resistance.

[0165] [Example B9] A blow-molded bottle (heat-resistant pressure bottle) was obtained in the same manner as in Example B1, except that the proportion of raw material polyester was the same as in Example A6. The yield during blow molding was 100%.

[0166] [Reference Example 3] Manufacturing of general-purpose 100% PET bottles A blow-molded bottle was obtained in the same manner as in Example B1, except that polyester (G) was used as the raw material instead of polyester (C). The performance of the obtained bottle is shown in Table 4.

[0167] The results of Examples B1-B8, Comparative Examples B1-B4, and Reference Example 3 described above are summarized in Table 4.

[0168] [Table 4]

[0169] The following was found from the results summarized in Table 4. A comparison of Examples B1, B2, and B8 with Comparative Examples B1 to B3 confirms that the polyester of this embodiment is suitable for blow-molded bottles because, despite the general consensus that an intrinsic viscosity of 0.7 dL / g is desirable for PET bottles, its intrinsic viscosity is significantly higher. In particular, blow-molded bottles manufactured using the polyester of this embodiment have a low weight / volume ratio, are thin and lightweight, yet possess high oxygen barrier properties, making them suitable for filling with liquids that are easily oxidized by air, such as wine. Furthermore, they exhibit high creep resistance and impact resistance even when filled with highly concentrated carbonated water, making them suitable for filling with carbonated beverages and other carbonated liquids. Moreover, because the polyester of this embodiment contains structural units derived from 2,5-franzicarboxylic acid, it has a high glass transition temperature and excellent heat resistance, making it suitable for use as a bottle for hot beverages. Furthermore, the polyester in this embodiment exhibits good blow-molding properties, and by using it, a blow-molded bottle with excellent oxygen barrier properties, impact resistance, and creep resistance can be obtained. This is thought to be because, as shown in Figure 1, the higher the intrinsic viscosity of the polyester, the higher the strain-hardening properties, which allows for the molding of more uniform and thinner bottles.

[0170] Furthermore, a comparison of Examples B3 to B7 with Comparative Example B4 confirmed that using polyethylene terephthalate in combination with polyester, which has structural units derived from 2,5-franzicarboxylic acid and aliphatic diols and has high intrinsic viscosity, improves blow moldability and enhances the oxygen barrier properties and creep resistance of polyethylene terephthalate. In other words, it was found that blow-molded bottles manufactured using the polyester of this embodiment become heat- and pressure-resistant bottles with excellent gas barrier properties, creep resistance, heat resistance, and impact resistance, making them suitable for applications such as filling hot beverages, carbonated liquids, and alcohol-containing liquids.

[0171] [Reference example 4] In a reaction vessel equipped with a stirrer, nitrogen inlet, heater, thermometer, and vacuum port, 85.7g of 2,5-franzicarboxylic acid (manufactured by V&V PHARMA INDUSTRIES), 68.16g of 1,2-ethanediol (manufactured by Mitsubishi Chemical), 0.036g of antimony trioxide (Sb2O2) (Sb concentration in the resulting polyester was 300ppm), and 0.029g of a 35 wt% aqueous solution of tetraethylammonium hydroxide were charged as raw materials, and the inside of the reaction vessel was subjected to a nitrogen atmosphere. Next, the reaction vessel was immersed in an oil bath set to 120°C, and the temperature was raised to 210°C over 60 minutes while stirring. The mixture was then held at 210°C for 200 minutes, and the distillate was collected to allow the esterification reaction to proceed. A portion of the reaction solution was taken and analyzed by nuclear magnetic resonance spectroscopy, which revealed an esterification reaction rate of 94%. Next, the temperature was raised to 260°C over 1.5 hours, and the pressure was gradually reduced from atmospheric pressure to approximately 130 Pa over 1.5 hours, after which it was maintained at 130 Pa. After 6 hours from the start of the reduced pressure, stirring was stopped, and the pressure was restored to terminate the polycondensation reaction. The produced polyester was extracted in strand form from the bottom of the reaction vessel, cooled through a cooling water bath, and then cut with a pelletizer to obtain polyester (K) in pellet form approximately 2-3 mm square. The intrinsic viscosity of polyester (K) was 0.65 dL / g. Furthermore, the amount of terminal groups was 12 eq / t for carboxyl terminal groups, 97 eq / t for hydroxyl terminal groups, and 12 eq / t for decarboxyl terminal groups, with the ratio of the amount of decarboxyl terminal groups to the total amount of decarboxyl terminal groups being 0.5.

[0172] For the polyesters (I) to (K) obtained in Reference Examples 1, 2, and 4, we attempted to increase their molecular weight by solid-phase polymerization. 10 g of pellets were placed in an inert oven and heated at 120°C for 6 hours with nitrogen gas flowing at a rate of 30 L / min. After cooling to room temperature (25°C), the fused pellets were thawed. Furthermore, solid-phase polymerization was carried out by heating these pellets at 150°C for 3 hours, 180°C for 3 hours, and 200°C for 9 hours. The intrinsic viscosity of the polyesters after solid-phase polymerization is shown in Table 5.

[0173] [Table 5]

[0174] Table 5 shows that when the amount of decarboxylated end groups (C) is high, or when the ratio of decarboxylated end groups to the total amount of decarboxylated end groups and carboxyl end groups (C / (B+C)) exceeds 0.5, the solid-phase polymerization rate slows down. It was also shown that polymerization proceeds faster with the titanium catalyst than with the antimony catalyst.

Claims

1. A polyethylene furanoate having an intrinsic viscosity of 1.1 dl / g or more and 1.50 dl / g or less, as measured by the following method, The 1,2-ethanediol structural units constitute 50 mol% or more of the total diol structural units contained in the polyethylene furanoate, A polyethylene furanoate in which aliphatic diol structural units constitute 100 mol% of the total diol structural units contained in the polyethylene furanoate. Dissolve 0.25 g of polyethylene furanoate in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio), and measure the viscosity using an Ubbelohde viscometer at 30°C. The Huggins constant is assumed to be 0.

32.

2. The polyethylene furanoate according to claim 1, wherein the polyethylene furanoate contains 1 to 100 ppm of titanium atoms.

3. A polyethylene furanoate according to claim 1 or 2, for use in blow-molded bottles.

4. A polyester composition containing polyethylene furanoate according to any one of claims 1 to 3, and a thermoplastic resin other than the polyethylene furanoate.

5. The polyester composition according to claim 4, wherein the polyethylene furanoate content is 1 to 20% by weight, and the thermoplastic resin is polyethylene terephthalate.

6. A polyester composition containing 50% by weight or more of polyethylene furanoate, further containing a crosslinkable thermoplastic resin and / or another thermoplastic polyester resin other than the polyethylene furanoate, wherein the other thermoplastic polyester resin contains terephthalic acid structural units. The polyester composition according to claim 4, further comprising structural units selected from 1,4-butanediol structural units and polytetramethylene glycol structural units.

7. A method for manufacturing a polyester bottle containing polyethylene furanoate, An injection molding process for manufacturing a preform from raw polyester, and The process includes a blow molding step for manufacturing a bottle from the aforementioned preform, A method for producing a polyester bottle, wherein the raw material polyester contains polyethylene furanoate according to any one of claims 1 to 3.

8. A blow-molded bottle which is a molded article of polyethylene furanoate according to any one of claims 1 to 3, or a polyester composition according to any one of claims 4 to 6.

9. A blow-molded bottle according to claim 8, for filling with a carbonated liquid.

10. A blow-molded bottle according to claim 8, for filling hot beverages.

11. A beverage product comprising a blow-molded bottle according to any one of claims 8 to 10, filled with a beverage.

Images