Polyethylenefurandicarboxylate, method for producing high-viscosity polyethylenefurandicarboxylate, polyester composition, polyester bottle, method for producing polyester bottle, and beverage product

Abstract

A polyethylene furanoate having an intrinsic viscosity of 0.95 dl / g or more and 1.50 dl / g or less. Herein, the intrinsic viscosity is measured by dissolving 0.25 g of the polyethylene furanoate in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (weight ratio) using an Ubbelohde viscometer at 30°C (Huggins constant is set to 0.32).

Description

Technical Field

[0001] This invention relates to polyethylene furanate dicarboxylate, which can be manufactured from biomass raw materials and has excellent heat resistance and gas barrier properties; polyester compositions containing polyethylene furanate dicarboxylate; bottles using these compositions that have excellent heat resistance, gas barrier properties, creep resistance and impact resistance; methods for manufacturing high-viscosity polyesters; and methods for manufacturing bottles. Background Technology

[0002] In recent years, from an environmental perspective, there has been an increased demand for polyesters made from plant-based raw materials.

[0003] Regarding plant-derived raw materials for polyesters, examples of dicarboxylic acids include succinic acid, glutaric acid, sebacic acid, ferulic acid, caffeic acid, 2,5-furandicarboxylic acid, and ethylene glycol. Examples of diols include ethylene glycol, propylene glycol, butanediol, and isosorbide. Among these, 2,5-furandicarboxylic acid has attracted considerable attention as a potential alternative to terephthalic acid.

[0004] Polyesters using 2,5-furandicarboxylic acid include polybutylene furandicarboxylate, polypropylene furandicarboxylate, polyethylene furandicarboxylate, and polyalkylene furandicarboxylate, among which polyethylene furandicarboxylate (PEF) is expected to be a substitute polyester for polyethylene terephthalate (PET) used in various industrial applications.

[0005] For example, Patent Document 1 discloses a preform containing polyethylene furanate for manufacturing plastic containers by stretch blow molding. Specifically, it describes that by producing a preform with 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, regarding polyethylene terephthalate containers, an intrinsic viscosity of approximately 0.7 is considered suitable, as it is known that flowability and formability deteriorate when the viscosity exceeds 0.9, which is undesirable (see Patent Document 2).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Publication No. 2018-510800

[0010] Patent Document 2: Japanese Patent Application Publication No. 2000-79633 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, the inventors conducted research on containers made of polyethylene furanate and determined that polyethylene furanate has insufficient blow molding properties and insufficient impact resistance of blow-molded containers made of polyethylene furanate.

[0013] The present invention was made in view of the problems of the prior art described above. That is, the object of the present invention is to provide a polyester that can be manufactured from raw materials derived from biomass, which has excellent heat resistance, gas barrier properties and blow molding properties, a polyester composition containing the polyester, and bottles using the polyester that have excellent heat resistance, gas barrier properties and impact resistance.

[0014] Methods for solving problems

[0015] The inventors conducted repeated research to solve the aforementioned problems. They discovered that using polyethylene furanate with a specific intrinsic viscosity could solve these problems. Furthermore, they found that using a polyester composition containing polyethylene furanate and other thermoplastic resins could also solve these problems. Moreover, they discovered that in a method for manufacturing high-viscosity polyethylene furanate, which includes a step of manufacturing the raw material polyethylene furanate and a step of solid-state polymerization of the raw material polyethylene furanate, using a specific catalyst in the step of manufacturing the polyethylene furanate yields a raw material polyethylene furanate with a specific intrinsic viscosity and a specific amount of decarboxylation-terminated groups. By subjecting this to solid-state polymerization, a high-viscosity polyester not obtained by existing methods can be obtained, which is effective in solving the aforementioned problems.

[0016] That is, the main idea of ​​this invention is as follows. [1]

[0018] A poly(ethylene furanate) having an intrinsic viscosity of ≥0.95 dl / g and ≤1.50 dl / g, as determined by the following method.

[0019] 0.25 g of polyethylene furanate was dissolved in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (by weight). The viscosity was measured using an Ubbelohde viscometer at 30 °C, and the Huggins constant was set to 0.32. [2]

[0021] The poly(ethylene furanate) as described in [1] contains 1 to 100 ppm of titanium atoms. [3]

[0023] Polyethylene furanate as described in [1] or [2] is used for blow-molded bottles. [4]

[0025] A bottle made of polyethylene furanate dicarboxylate has an intrinsic viscosity of ≥0.75 dl / g and ≤1.2 dl / g, as determined by the following method.

[0026] Dissolve 0.25g of the tablet in 50ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (by weight), and measure the viscosity using an Ubbelohde viscometer at 30°C. The Huggins constant was set to 0.32. [5]

[0028] As described in [4], the polyfuran dicarboxylate bottle has a crystallinity of more than 10% and less than 40% as determined by wide-angle X-ray diffraction using the following formula.

[0029] Crystallinity (%) = Peak area of ​​crystalline material / (Peak area of ​​crystalline material + Peak area of ​​amorphous material) × 100 [6]

[0031] A method for manufacturing high-viscosity polyethylene furanate includes a polyethylene furanate raw material manufacturing step using a titanium catalyst, and a solid-phase polymerization step of subjecting the aforementioned polyethylene furanate raw material to solid-phase polymerization.

[0032] The intrinsic viscosity of the above-mentioned raw material, polyethylene furanate, as determined by the following method, is ≥0.65 dl / g and ≤0.85 dl / g, and the amount of decarboxylation terminal groups in the following formula is ≤20 eq / t.

[0033] 0.25 g of polyethylene furanate was dissolved in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (by weight). The viscosity was measured using an Ubbelohde viscometer at 30 °C, and the Huggins constant was set to 0.32.

[0034] [7]

[0036] The method for manufacturing high-viscosity polyethylene furanate as described in [6], wherein the ratio of the amount of decarboxylation terminal groups to the total amount of decarboxylation terminal groups and carboxylation terminal groups in the above-mentioned raw material polyethylene furanate is 0.5 or less. [8]

[0038] A polyester composition comprising any one of [1] to [3] polyethylene furanate and a thermoplastic resin other than the aforementioned polyethylene furanate. [9]

[0040] The polyester composition as described in [8], wherein the content of the above-mentioned polyethylene furanate is 1 to 20% by weight, and the above-mentioned thermoplastic resin is polyethylene terephthalate.

[10]

[0042] A polyester composition comprising 50% by weight or more of polyethylene furanate, wherein the composition further comprises a crosslinked thermoplastic resin and / or other thermoplastic polyester resins other than the aforementioned polyethylene furanate, wherein the aforementioned other thermoplastic polyester resins have terephthalic acid structural units and have structural units selected from 1,4-butanediol structural units and polybutanediol structural units.

[11]

[0044] A method for manufacturing polyester bottles, comprising a method for manufacturing polyester bottles containing polyethylene furanate, wherein,

[0045] It has an injection molding process for manufacturing a preform from raw polyester and a blow molding process for manufacturing a bottle from the preform.

[0046] The above-mentioned raw material polyester contains polyethylene furanate as described in any one of [1] to [3].

[12]

[0048] A method for manufacturing polyester bottles, comprising a method for manufacturing polyester bottles containing polyethylene furanate, wherein,

[0049] It has an injection molding process for manufacturing a preform from raw polyester and a blow molding process for manufacturing a bottle from the preform.

[0050] The above-mentioned raw material polyester is the polyester composition described in

[10] .

[13]

[0052] A blow-molded bottle, which is a molded body of any one of the following: polyethylene furanate dicarboxylate or any one of the following: [1] to [3] or a polyester composition of any one of the following: [8] to

[10] .

[14]

[0054] Blow-molded bottles, as described in

[13] , are used to fill carbonated liquids.

[15]

[0056] Blow-molded bottles, as described in

[13] , are used to fill hot beverages.

[16]

[0058] A beverage article which is a beverage article filled in a bottle described in [4] or [5] or a blow-molded bottle described in any one of

[13] to

[15] .

[0059] Invention Effects

[0060] The polyethylene furanate and polyester composition of the present invention can use raw materials derived from biomass, exhibits excellent heat resistance and gas barrier properties, and consequently, excellent blow molding properties. Therefore, it is particularly suitable for blow molding bottle applications, yielding lightweight bottles with excellent impact resistance. Furthermore, it is also suitable as a polyester for use as a gas barrier material that can replace polyamide-based gas barrier materials. Attached Figure Description

[0061] Figure 1 This is a graph showing the stroke-stress of Examples A1 to A8 and Comparative Example A1. Detailed Implementation

[0062] The following describes representative methods for implementing the present invention, but the present invention is not limited to these methods as long as it does not depart from its spirit.

[0063] In this specification, "structural unit derived from..." refers to a structural unit derived from the monomer and incorporated into the polyester as a polymer. Hereinafter, "structural unit derived from..." will be abbreviated as "unit" or "structural unit". For example, "structural unit derived from diol" may be abbreviated as "diol unit" or "diol structural unit", "structural unit derived from dicarboxylic acid" as "dicarboxylic acid unit" or "dicarboxylic acid structural unit", "structural unit derived from 2,5-furandicarboxylic acid" as "2,5-furandicarboxylic acid unit" or "2,5-furandicarboxylic acid structural unit", and "structural unit derived from 1,2-ethylene glycol" as "1,2-ethylene glycol unit" or "1,2-ethylene glycol structural unit".

[0064] In addition, in this specification, "main structural unit" refers to the structural unit that accounts for the largest proportion in the "structural unit", which is usually 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 unit.

[0065] One aspect of the invention is polyethylene furanate. The polyethylene furanate of this embodiment is particularly suitable for blow-molded bottle applications.

[0066] In this embodiment of polyethylene furandicarboxylate, 2,5-furandicarboxylic acid unit is used as the main structural unit of all dicarboxylic acid units constituting the polyester, and 1,2-ethylene glycol structural unit is used as the main structural unit of all diol units constituting the polyester.

[0067] Polyethylene furanate

[0068] The poly(ethylene furanate) of this embodiment has structural units derived from 2,5-furandicarboxylic acid and 1,2-ethylene glycol.

[0069] <Dicarboxylic acid structural unit>

[0070] The polyethylene furanyl dicarboxylate of this embodiment contains structural units derived from 2,5-furanyl dicarboxylic acid as dicarboxylic acid structural units. By including structural units derived from 2,5-furanyl dicarboxylic acid, the glass transition temperature is increased, heat resistance is improved, and consequently, gas barrier properties are also improved. The polyethylene furanyl dicarboxylate of this embodiment preferably uses structural units derived from 2,5-furanyl dicarboxylic acid as the main dicarboxylic acid unit. That is, the structural units derived from 2,5-furanyl dicarboxylic acid typically contain 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and even more preferably 90 to 100 mol% of all dicarboxylic acid structural units per 100 mol%.

[0071] The polyethylene furanate of this embodiment may also have dicarboxylic acid (also called "other dicarboxylic acids") structural units other than 2,5-furandicarboxylic acid units as dicarboxylic acid units. Examples of other dicarboxylic acids include aliphatic dicarboxylic acids and aromatic dicarboxylic acids. Examples of aliphatic dicarboxylic acids include: oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dimer acids, dodecanoic acid, and other chain-like aliphatic dicarboxylic acids; 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. Among these dicarboxylic acids, aliphatic dicarboxylic acids are preferred from the perspective of excellent flexibility, and chain-like aliphatic dicarboxylic acids are more preferred.

[0072] Regarding the inclusion of other dicarboxylic acid structural units as dicarboxylic acid structural units, the other dicarboxylic acid structural units may be only one type, or two or more types may be included in any combination and ratio. From the viewpoint of easily and sufficiently obtaining the aforementioned effects brought about by the inclusion of 2,5-furandicarboxylic acid structural units, the content of other dicarboxylic acid structural units in the polyethylene ethylene furanate of this embodiment is preferably low. Furthermore, from the viewpoint of excellent flexibility, the content of other dicarboxylic acid structural units in the polyethylene ethylene furanate of this embodiment is preferably high. Therefore, when other dicarboxylic acid structural units are included, their content is typically 10 mol% or more, preferably 20 mol% or more, more preferably 30 mol% or more, and the upper limit is typically 50 mol%.

[0073] By using dicarboxylic acid components such as dicarboxylic acid, dicarboxylic acid anhydride, lower alkyl esters of dicarboxylic acid (alkyl groups with 1 to 4 carbon atoms), and chlorides of dicarboxylic acid as raw materials for manufacturing the polyethylene furanate of this embodiment, dicarboxylic acid structural units can be introduced into the polyethylene furanate.

[0074] <Diol structural unit>

[0075] In this embodiment, 1,2-ethylene glycol structural units are included as diol structural units. By including 1,2-ethylene glycol structural units, the heat resistance and gas barrier properties of bottles made using polyethylene furanate are improved.

[0076] As a diol structural unit, it can contain diols other than 1,2-ethylene glycol (hereinafter also referred to as "other diols") as structural units. Examples of other diols include aliphatic diols other than 1,2-ethylene glycol (hereinafter also referred to as "other aliphatic diols") and aromatic diols. Examples of other aliphatic diol structural units include 2,2'-oxodiethanol, 2,2'-(ethylenedioxy)diethanol, 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanediethanol, ethylene glycol, diethylene glycol, triethylene glycol, isosorbide, etc.

[0077] In addition, examples of aromatic diols include benzenediethanol, 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.

[0078] When the poly(ethylene furanate) of this embodiment contains other diol structural units, the other diols may be only one type, or they may contain two or more types in any combination and ratio.

[0079] 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, with 1,4-butanediol being particularly preferred. The polyethylene furanate of this embodiment preferably uses structural units derived from aliphatic diols as the main diol structural units. That is, from the viewpoint of improving heat resistance and gas barrier properties, it is preferred that the aliphatic diol structural units typically contain 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, and particularly preferably 100 mol% of all diol structural units contained in the polyethylene furanate.

[0080] <Other Copolymer Components>

[0081] The polyethylene furanate of this embodiment may also contain structural units derived from other copolymer components besides dicarboxylic acids and diols. Examples of other copolymer components include compounds having three or more functional groups.

[0082] Compounds with three or more functional groups can be listed as polyols with three or more functional groups, polycarboxylic acids with three or more functional groups (or their anhydrides, acyl chlorides or lower alkyl esters), hydroxycarboxylic acids with three or more functional groups (or their anhydrides, acyl chlorides or lower alkyl esters), and amines with three or more functional groups.

[0083] Examples of polyols with trifunctional or higher functions include glycerol, trimethylolpropane, and pentaerythritol. They can be used alone or in any combination and ratio of two or more.

[0084] Examples of trifunctional or higher polycarboxylic acids or their anhydrides include pyromellitic acid, propane tricarboxylic acid, trimellitic anhydride, pyromellitic tetracarboxylic anhydride, benzophenone tetracarboxylic anhydride, and cyclopentane tetracarboxylic anhydride. They can be used individually or in any combination and ratio of two or more.

[0085] Examples of trifunctional or higher hydroxycarboxylic acids include malic acid, hydroxyglutaric acid, hydroxymethylglutaric acid, tartaric acid, citric acid, hydroxyisophthalic acid, and hydroxyterephthalic acid. They can be used alone or in any combination and ratio of two or more.

[0086] From the perspective of easily improving strain curing properties, the poly(ethylene furanate) of this embodiment preferably contains a higher content of structural units derived from compounds having three or more functional groups. On the other hand, from the perspective of the poly(ethylene furanate) of this embodiment having moderate crosslinking, easy and stable strand drawing, and improved formability and mechanical properties, the poly(ethylene furanate) of this embodiment preferably contains a lower content of structural units derived from compounds having three or more functional groups. Therefore, its content relative to the total 100 mol% of all structural units constituting the poly(ethylene furanate) is preferably typically 5 mol% or less, particularly 4 mol% or less, especially 3 mol% or less, and most preferably a binary polyester without other copolymer components.

[0087] <Chain extender>

[0088] In manufacturing the polyethylene furanate of this embodiment, carbonate compounds, diisocyanate compounds, and other similar compounds can be used. Chain extenders such as zoline and silicate esters. For example, polyurethane carbonate can also be obtained by using a carbonate compound such as diphenyl carbonate, which is preferably 20 mol% or less, more preferably 10 mol% or less, relative to all structural units of polyethylene furanate.

[0089] In this case, examples of carbonate compounds include diphenyl carbonate, xylene carbonate, bis(chlorophenyl) carbonate, m-toluene carbonate, dinaphthalene carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diethyl carbonate, diethylene carbonate, dipentyl carbonate, and dicyclohexyl carbonate. Additionally, carbonate compounds derived from hydroxyl compounds such as phenols and alcohols, and composed of the same or different hydroxyl compounds, can also be used.

[0090] In addition, as diisocyanate compounds, specific examples include 2,4-toluene diisocyanate, mixtures of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, phenylmethylene diisocyanate, hydrogenated phenylmethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and other known diisocyanates.

[0091] As silicates, examples include tetramethoxysilane, dimethoxydiphenylsilane, dimethoxydimethylsilane, and diphenyldihydroxysilane.

[0092] They can each be used individually, or two or more can be used in any combination and ratio.

[0093] <End-capping agent>

[0094] In this embodiment, carbodiimide, epoxy compounds, monofunctional alcohols, or carboxylic acids can be used to block the terminal groups of polyethylene furanate. When using a capping agent, its content is preferably set to 20 mol% or less, more preferably 10 mol% or less, relative to 100 mol% of all structural units of polyethylene furanate.

[0095] In this case, carbodiimide compounds used as end-capping agents can include compounds having one or more carbodiimide groups in their molecules (including polycarbodiimide compounds). Specifically, examples of monocarbodiimide compounds include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, tert-butylisopropylcarbodiimide, diphenylcarbodiimide, di-tert-butylcarbodiimide, di-β-naphthylcarbodiimide, and N,N'-di-2,6-diisopropylphenylcarbodiimide.

[0096] They can each be used individually, or two or more can be used in any combination and ratio.

[0097] It should be noted that, in the manufacture of the polyethylene furanate in this embodiment, similar to the polyester composition of this embodiment described later, various additives, such as heat stabilizers, antioxidants, hydrolytic agents, crystallizing nucleating agents, flame retardants, antistatic agents, mold release agents, and ultraviolet absorbers, can be used without impairing its properties.

[0098] As described above, the polyethylene furanate of this embodiment may contain structural units other than structural units derived from 2,5-furandicarboxylic acid and structural units derived from 1,2-ethylene glycol. However, even in this case, the total amount of structural units derived from 2,5-furandicarboxylic acid and structural units derived from 1,2-ethylene glycol is preferably 80 mol% or more, and more preferably 90 mol% or more, relative to 100 mol% of all structural units of the polyethylene furanate.

[0099] The raw materials used to manufacture the polyethylene furanate of this embodiment can be petroleum-derived or biomass-derived. From an environmental protection perspective, biomass-derived raw materials are preferred, and biomass-derived raw materials are more preferably used as the main structural unit. Examples of biomass-derived raw materials include dicarboxylic acids such as 2,5-furandicarboxylic acid, succinic acid, glutaric acid, adipic acid, and sebacic acid, as well as diols such as 1,3-propanediol, 1,4-butanediol, and 1,2-ethylenediol.

[0100] <Method for manufacturing polyethylene furanate>

[0101] As a method for manufacturing polyethylene furanate in this embodiment, a known method related to the manufacture of polyethylene furanate resin can be used.

[0102] In addition, the reaction conditions at this time can be set to the appropriate conditions used in the past, without any particular restrictions.

[0103] Specifically, the product can be manufactured by using a dicarboxylic acid component with 2,5-furandicarboxylic acid as an essential component, 1,2-ethylene glycol, and other copolymer components as needed, through an esterification or transesterification process, followed by a polycondensation process. It should be noted that the esterification or transesterification process and the polycondensation process are collectively referred to as the polyethylene furanate raw material manufacturing process. Furthermore, the polyethylene furanate obtained through the polyethylene furanate raw material manufacturing process is sometimes simply referred to as "polyethylene furanate" or "raw material polyethylene furanate." During the reaction, the aforementioned chain extenders and end-capping agents can be used as needed. Additionally, from the perspective of improving intrinsic viscosity, it is preferable to further perform a solid-state polymerization process after the polycondensation process in the polyethylene furanate raw material manufacturing process.

[0104] <Esterification or transesterification process>

[0105] Esterification or transesterification reactions are typically carried out as follows: Dicarboxylic acid components, diol components, and other copolymer components, if necessary, are added to a reaction vessel equipped with a stirrer and a distillation tube. The reaction is preferably carried out under reduced pressure in the presence of a catalyst and an inert gas atmosphere, while stirring and distilling off byproducts such as water generated during 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 typically 1.0 to 3.0 molar times. A higher diol content facilitates a more complete esterification reaction, reduces the number of decarboxylation ends, and is preferred from the perspective of easily obtaining poly(ethylene furanate dicarboxylate) with fewer carboxyl-terminal groups than hydroxyl-terminal groups through polycondensation. On the other hand, a lower diol content is preferred from the perspective of minimizing the formation of ether structures due to side reactions from aliphatic diol components. Therefore, the lower limit of this molar ratio is preferably 1.25 molar times, more preferably 1.30 molar times. Furthermore, the upper limit is preferably 2.5 molar times, more preferably 2.0 molar times.

[0106] From the perspective of easily obtaining poly(ethylene furanate) with a small amount of decarboxylation terminal groups, the esterification or transesterification reaction is preferably carried out in a manner that increases the reaction rate of the esterification reaction; specifically, it is preferable to extend the reaction time at a lower temperature. This increases the reaction rate of the esterification reaction and reduces the generation of byproducts.

[0107] 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. Here, by allowing the esterification or transesterification reaction to proceed sufficiently, side reactions such as the decarboxylation reaction of furanyl dicarboxylic acid are less likely to occur, and subsequent condensation and solid-state polymerization reactions are easier to carry out. Furthermore, the formation of ether structures caused by side reactions from the diol component is less likely to occur, thus improving heat resistance. The reaction pressure is typically from atmospheric pressure to 10 kPa, preferably atmospheric pressure. The reaction atmosphere is typically an inert gas atmosphere such as nitrogen or argon. The reaction time is typically 1 hour or more, with an upper limit typically of 10 hours, preferably 8 hours. The reaction rate can be determined by quantifying the unreacted carboxylic acid termini from the furanyl dicarboxylic acid component. The reaction rate at the end of the reaction is preferably set to 85 mol% or higher, more preferably 90 mol% or higher.

[0108] <Polycondensation reaction process>

[0109] Polycondensation is typically carried out under reduced pressure after esterification or transesterification. To minimize the formation of byproducts, polycondensation is preferably initiated at a temperature lower than the initial temperature at which reduced pressure is applied.

[0110] The reaction temperature is preferably set above and below the melting point of the obtained polyethylene furanate dicarboxylate by 100°C. This preferred range of reaction temperature and melting point of the obtained polyethylene furanate dicarboxylate can be confirmed by predicting the approximate melting point of the obtained polyethylene furanate dicarboxylate and measuring the melting point after the reaction. 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, more preferably 270°C or lower. By setting the reaction temperature within these ranges, the reaction can proceed at a sufficiently fast rate without easily causing discoloration or other problems due to thermal decomposition or side reactions. In particular, since the decarboxylation reaction of furanate dicarboxylic acid is less likely to occur, carboxyl-terminal groups are less likely to form compared to hydroxyl-terminal groups, thus facilitating the continuation of the solid-state polymerization reaction.

[0111] Regarding the reaction pressure, decompression begins at any point when the temperature is reached. The final pressure is typically 0.01 × 10⁻⁶. 3 Pa or higher, preferably 0.05 × 10 Pa 3 Pa or higher. Additionally, it is typically 1.4 × 10⁻⁶. 3 Pa below, preferably 0.6 × 10 Pa 3 Pa or less, more preferably 0.3 × 10 Pa 3Below Pa. When the reaction pressure is low, polymerization can proceed quickly, reducing the likelihood of molecular weight loss and discoloration caused by the thermal decomposition of polyethylene furanate, and resulting in polyethylene furanate exhibiting practically sufficient properties. Furthermore, from the perspective of avoiding the use of expensive equipment, a slightly higher reaction pressure is preferable.

[0112] The reaction time is typically 1 hour to 15 hours. Preferably, it is 10 hours or less, more preferably 8 hours or less. A longer reaction time allows for a more complete reaction, easily yielding polyethylene furanate with a high degree of polymerization and excellent mechanical properties. Conversely, a shorter reaction time reduces the likelihood of molecular weight reduction due to thermal decomposition of the polyethylene furanate, thus easily yielding polyethylene furanate with excellent mechanical properties.

[0113] After the polycondensation reaction is completed, polyethylene furanate dicarboxylate is usually drawn out in strands while in a molten state, cooled, and then cut into granules.

[0114] <Catalyst>

[0115] In the manufacturing process of polyethylene furanate raw materials, from the viewpoint that the viscosity of polyethylene furanate can be easily increased by further solid-state polymerization of the raw material polyethylene furanate obtained by polycondensation reaction, the reaction is preferably carried out in the presence of a titanium catalyst. The amount of titanium catalyst used, calculated as Ti element, is preferably 1 to 100 ppm in the polyethylene furanate, more preferably 1 to 50 ppm. Furthermore, relative to 1 mole of the dicarboxylic acid component of the raw material, the Ti element concentration is preferably 0.000001 mol or more, more preferably 0.000002 mol or more, and even more preferably 0.0000038 mol or more. On the other hand, this 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.

[0116] By adjusting the amount of titanium catalyst within these ranges, polyethylene furanate can be produced while efficiently suppressing the decarboxylation reaction of furanate at a fast polymerization rate. This results in polyethylene furanate with minimal coloration, excellent melt thermal stability, and good hydrolytic properties. Furthermore, by further solid-state polymerization, high-viscosity polyethylene furanate can be obtained.

[0117] There is no particular time limit for adding the catalyst; it can be added when the raw materials are fed in or during the manufacturing process. Alternatively, it can be added in two or more equal parts, once when the raw materials are fed in and once during the manufacturing process.

[0118] There are no particular limitations on the titanium compounds used as catalysts. Tetraalkyl titanates are preferred as titanium compounds. Specifically, examples include tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetratert-butyl titanate, tetraoctyl titanate, tetraphenyl titanate, tetracyclohexyl titanate, tetrabenzyl titanate, and mixed titanates thereof. Other examples include titanium acetylacetone (oxy) ester, tetraacetylacetone titanium, (diisopropoxy)acetylacetone titanium, dihydroxybis(ammonium lactate) titanium, bis(ethyl acetoacetate) diisopropyl titanate, (triethanolamine) isopropoxide titanium, polyhydroxy stearate titanium, tetrastearate titanate, titanium lactate, triethanolamine titanium, and tetrabutyl titanate dimers. Furthermore, examples include titanium oxide and composite oxides containing titanium and silicon.

[0119] Among them, tetraisopropyl titanate, tetrabutyl titanate, tetraoctyl titanate, acetylacetone (oxy) titanium, tetraacetylacetone titanium, polyhydroxy stearate titanium, tetrastearate titanate, lactate titanium, butyl titanate dimer or titanium dioxide / silica composite oxide are preferred.

[0120] In addition to titanium catalysts, metal compounds of germanium, zirconium, hafnium, antimony, tin, magnesium, calcium, zinc, aluminum, cobalt, lead, cesium, manganese, lithium, potassium, sodium, copper, and barium can also be used in combination. Among these, germanium compounds, magnesium compounds, tin compounds, and zinc compounds are preferred, with magnesium compounds and germanium compounds being particularly preferred.

[0121] These catalysts can be used alone, or two or more can be used in any combination and ratio. Furthermore, other catalysts can be used in combination, provided that the purpose of this invention is not compromised.

[0122] <Additives>

[0123] In the manufacturing process of polyethylene furanate raw materials, heat stabilizers can be used. By using heat stabilizers, thermal decomposition during the polymerization reaction can be suppressed. Known heat stabilizers can be used as heat stabilizers. Specifically, hindered phenolic compounds, hindered amine compounds, and phosphorus compounds can be listed. Among these, phosphorus compounds are preferred.

[0124] In addition, tetraethylammonium hydroxide, alkali metal compounds, phosphorus compounds, and other substances can be used to suppress the associated formation of ether components caused by side reactions in the manufacture of polyethylene terephthalate.

[0125] When using these additives, they can be added during the raw material input, or during the manufacturing process of polyethylene furanate, or during the extraction stage of the manufactured polyethylene furanate. Alternatively, they can be added to the product after extraction.

[0126] Intrinsic Viscosity

[0127] The intrinsic viscosity of the raw material polyethylene furanate 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 typically 0.85 dl / g or lower. By maintaining the intrinsic viscosity within the above range, the extraction and cutting processes of the polyethylene furanate after the polycondensation reaction can be performed smoothly, easily yielding polyethylene furanate with excellent mechanical properties. Additionally, by subsequently performing solid-state polymerization after the polycondensation reaction, it is easier to achieve a higher viscosity. The intrinsic viscosity of the raw material polyethylene furanate can be adjusted by the polymerization temperature, polymerization time, and polymerization pressure during the manufacturing of the raw material polyethylene furanate. Furthermore, as described later, by further solid-state polymerization, the raw material polyethylene furanate after the polycondensation reaction can be made to achieve an even higher viscosity.

[0128] The intrinsic viscosity of the raw material, polyethylene furanate, was determined as follows: 0.25 g of the raw material, polyethylene furanate, was accurately weighed and dissolved in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (50 / 50 by weight). The resulting solution was then measured using an Ubbelohde viscometer at 30°C. The Huggins constant was set to 0.32.

[0129] <Amount of terminal groups>

[0130] The amount of decarboxylation terminal groups in the raw material polyethylene furanate according to the following formula is preferably 20 eq / t or less, more preferably 10 eq / t or less. On the other hand, the amount of decarboxylation terminal groups is usually 0.01 eq / t or more.

[0131]

[0132] By ensuring that the amount of decarboxylation-terminated groups in the raw material polyethylene furanate is below the aforementioned specific amount, solid-state polymerization is carried out immediately after the polycondensation reaction, thereby making it easier to achieve a high viscosity. As described above, the amount of decarboxylation-terminated groups in the raw material polyethylene furanate can be adjusted by studying the conditions of the esterification or transesterification reaction and the polycondensation reaction. To reduce the amount of decarboxylation-terminated groups, it is preferable to carry out the esterification or transesterification reaction in a manner that increases the reaction rate. Specifically, it is preferable to extend the reaction time at a lower temperature. This increases the reaction rate of the esterification reaction and reduces the generation of byproducts. Furthermore, considering the reduction of byproduct generation, the polycondensation reaction is preferably carried out at a temperature lower than the temperature at which the reduced pressure is started. Therefore, by confirming the amount of decarboxylation-terminated groups in the raw material polyethylene furanate produced by carrying out the esterification or transesterification reaction and the polycondensation reaction under the aforementioned preferred conditions, and selecting the raw material polyethylene furanate with the desired content, it is possible to obtain a raw material polyethylene furanate with the amount of decarboxylation-terminated groups below the specific amount.

[0133] Regarding the amount of hydroxyl-terminated groups and carboxyl-terminated groups in the raw material polyethylene furanate, from the perspective of facilitating subsequent solid-state polymerization, it is preferable that the amount of carboxyl-terminated groups is less than the amount of hydroxyl-terminated groups. Specifically, relative to the total amount of carboxyl-terminated groups and hydroxyl-terminated groups, the amount of carboxyl-terminated 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, this ratio is generally 0.01 or more. As described above, the relative amounts of hydroxyl-terminated groups and carboxyl-terminated groups can be adjusted by the amount of raw material diol, the amount of dicarboxylic acid, the polycondensation temperature, etc. Then, by confirming the amount of carboxyl-terminated groups and hydroxyl-terminated groups in the raw material polyethylene furanate thus manufactured, and selecting the desired relative amount of polyester, it is possible to obtain a raw material polyethylene furanate with the amount of carboxyl-terminated groups and hydroxyl-terminated groups within a specific range.

[0134] The amount of decarboxyl-terminated groups and hydroxyl-terminated groups of the raw material polyethylene furanate can be quantified as follows: 10–20 mg of the raw material polyethylene furanate is collected and dissolved in 1 g of a mixed solvent of deuterated chloroform / hexafluoroisopropanol d2 (2 / 1 weight ratio), and 60 μl of pyridine-d5 is further added. The sample prepared in this way is measured using a 400 MHz nuclear magnetic resonance spectrometer manufactured by Brucker. 1 ¹H-NMR is used for quantification.

[0135] Specifically, by conducting 1 The amount of decarboxyl-terminated groups and hydroxyl-terminated groups of the raw material poly(ethylene furanate) can be calculated using the following formula by H-NMR determination.

[0136] Amount of decarboxylation terminal groups (eq / t) = 4d / (182a+226c)×10 6

[0137] Amount of hydroxyl terminal groups (eq / t) = 2b / (182a+226c)×10 6

[0138] In the formula, a represents the cumulative peak value of the aliphatic diol structural unit, b represents the cumulative peak value of the hydroxyl-terminated group, c represents the cumulative peak value of the structural unit from the aliphatic diol condensate, and d represents the cumulative peak value of the decarboxylation-terminated group. Here, for the raw material polyethylene furanate dicarboxylate, in 1 In H-NMR, peaks of ethylene glycol (aliphatic diol) structural units were observed around 4.6–4.7 ppm, peaks of hydroxyl terminal groups were observed around 3.97–4.0 ppm, peaks of diethylene glycol (aliphatic diol condensate) structural units were observed around 3.88–3.9 ppm, and peaks of decarboxylation terminal groups were observed around 6.53–6.5 ppm.

[0139] In addition, the amount of carboxyl-terminated groups can be quantified using the following method. First, accurately weigh 0.3–0.4 g of polyethylene furanate dicarboxylate, add 25 mL of benzyl alcohol, and stir at 195°C for 7 minutes, visually confirming complete dissolution. Next, cool the solution using an ice bath, add 2 mL of ethanol, and titrate using a 0.01 N NaOH benzyl alcohol solution using an automatic titration apparatus “GT-200” manufactured by Mitsubishi Chemical Corporation. Here, the titration volume is set as A ml, and the blank value of the same determination using only the solvent is set as B ml. Substituting these values ​​into the following calculation formula, the amount of carboxyl-terminated groups can be calculated.

[0140] Amount of carboxyl-terminal groups (μeq / g) = (AB) × F × 10 / W

[0141] A[ml]: Measurement volume of titrant

[0142] B[ml]: Blank titration amount

[0143] F: Factor of 0.01N NaOH benzyl alcohol solution

[0144] W[g]: Sample weight

[0145] The ratio of the amount of decarboxylation terminal groups to the total amount of decarboxylation terminal groups and carboxylation terminal groups (hereinafter sometimes referred to as "the relative amount of decarboxylation terminal groups") is preferably 0.5 or less, more preferably 0.3 or less.

[0146] By ensuring that the relative amount of decarboxylation-terminal groups in the raw material polyethylene furanate is below the aforementioned specific value, the solid-state polymerization following the polycondensation reaction can proceed rapidly. As described above, the relative amount of decarboxylation-terminal groups in the raw material polyethylene furanate can be adjusted by studying the conditions of the esterification or transesterification reaction and the polycondensation reaction. To reduce the amount of decarboxylation-terminal groups, it is preferable to conduct the esterification or transesterification reaction in a manner that increases the reaction rate. Specifically, it is preferable to extend the reaction time at a lower temperature. This increases the reaction rate of the esterification reaction and reduces the likelihood of byproduct formation. Furthermore, considering the reduction of byproduct formation, the polycondensation reaction is preferably carried out at a temperature lower than the temperature at which the reduced pressure is started. Therefore, by conducting the esterification or transesterification reaction and the polycondensation reaction under the aforementioned preferred conditions, confirming the relative amount of decarboxylation-terminal groups in the produced raw material polyethylene furanate, and selecting the desired relative amount of raw material polyethylene furanate, it is possible to obtain a raw material polyethylene furanate with a relative amount of decarboxylation-terminal groups below the specific amount.

[0147] Solid-phase polymerization

[0148] As described above, for the raw material polyethylene furanate obtained by polycondensation reaction, it is preferable to further perform solid-state polymerization to increase its molecular weight and intrinsic viscosity. The reaction temperature of solid-state polymerization is not particularly limited as long as it is below the melting point of the polyethylene furanate resin; however, it is easier to increase the molecular weight and intrinsic viscosity of polyethylene furanate when the reaction is carried out at higher temperatures. Specifically, 80°C or higher is preferred, more preferably 100°C or higher, and even more preferably 120°C or higher. Furthermore, from the perspective of minimizing thermal decomposition and side reactions of polyethylene furanate, and readily obtaining polyesters with low carboxyl terminus concentration, less coloring, and high molecular weight, the reaction temperature is preferably a temperature lower than that of the polycondensation reaction.

[0149] There are no particular limitations on the solid-state polymerization method. For example, methods such as heating granular or powdered polyethylene furanate under an inert gas atmosphere or under reduced pressure can be cited. The reaction can be carried out while the granules or powder are stationary or under stirring. When stirring is performed, stirring blades installed inside the reaction vessel can be used, or stirring can be achieved by moving the reaction vessel.

[0150] The reaction time is typically 0.5 hours or more, preferably 1 hour or more, and more preferably 2 hours or more. Furthermore, it is preferably 60 hours or less, more preferably 50 hours or less, and even more preferably 45 hours or less. By extending the reaction time, the poly(ethylene furanate) tends to have a higher molecular weight and superior mechanical properties. Conversely, by shortening the reaction time, the poly(ethylene furanate) tends to be less prone to discoloration.

[0151] <Manufacturing Method of High Viscosity Polyester>

[0152] As described above, the polyethylene furanate of this embodiment preferably has a high intrinsic viscosity, and particularly preferably an intrinsic viscosity of 0.95 dl / g or higher. Such a high-viscosity polyethylene furanate can be obtained by solid-state polymerization of the raw material polyethylene furanate obtained from the above-described polycondensation reaction (hereinafter, the polyester obtained by solid-state polymerization is sometimes referred to as "high molecular weight polyethylene furanate" or "high-viscosity polyethylene furanate").

[0153] In particular, as a raw material, polyethylene furanate, a raw material polyethylene furanate with an intrinsic viscosity of 0.65 dl / g or more and 0.85 dl / g or less, and a decarboxylation terminal group amount of 20 eq / t or less, manufactured using a titanium catalyst, is subjected to solid-state polymerization. This allows the production of a high-viscosity polyethylene furanate that was previously unattainable (hereinafter, the method for producing this solid-state polymerized high-viscosity polyethylene furanate is sometimes referred to as "the method for producing high-viscosity polyethylene furanate of this embodiment").

[0154] That is, the method for manufacturing high-viscosity polyethylene furanate in this embodiment includes a polyethylene furanate raw material manufacturing step that uses a titanium catalyst to manufacture the raw material polyethylene furanate, and a solid-phase polymerization step that performs solid-phase polymerization on the above-mentioned raw material polyethylene furanate. In the solid-phase polymerization step, polyethylene furanate with an intrinsic viscosity of 0.65 dl / g or more and 0.85 dl / g or less and a decarboxylation terminal group amount of 20 eq / t or less is subjected to solid-phase polymerization.

[0155] Furthermore, as described above, in order to obtain high-viscosity polyethylene furanate by solid-state polymerization, the raw material polyethylene furanate preferably has a specific relative amount of decarboxylation terminal groups. Therefore, the method for manufacturing high-viscosity polyethylene furanate of this embodiment preferably uses the aforementioned polyethylene furanate with a specific relative amount of decarboxylation terminal groups as the raw material polyethylene furanate.

[0156] The method for manufacturing high-viscosity polyethylene furanate of this embodiment includes an esterification or transesterification reaction step with 2,5-furandicarboxylic acid and 1,2-ethylene glycol, a polycondensation reaction step, and a solid-state polymerization step. Furthermore, the inventors have discovered that by using a titanium catalyst in the polycondensation reaction step to adjust the conditions of the esterification or transesterification reaction and the polycondensation reaction in a way that controls the amount of decarboxylation terminal groups within a specific range, it is possible to obtain a high intrinsic viscosity polyethylene furanate that is unattainable using conventional methods, thus effectively solving the aforementioned problems.

[0157] It has been found that the above-mentioned problems can be solved by the manufacturing method of high-viscosity polyester described below. The manufacturing method of high-viscosity polyethylene furanate includes a raw material manufacturing step for manufacturing raw material polyethylene furanate having structural units derived from 2,5-furandicarboxylic acid and structural units derived from 1,2-ethylene glycol, and a solid-state polymerization step for solid-state polymerization of the raw material polyethylene furanate. The raw material manufacturing step is carried out using a titanium catalyst, and the raw material polyethylene furanate used in the solid-state polymerization step has an intrinsic viscosity of 0.65 dl / g or more and 0.85 dl / g or less, as determined by the following method, and the amount of decarboxylation terminal groups is 20 eq / t or less.

[0158] From the perspective of easily obtaining the desired high viscosity polyethylene furanate through short-time solid-state polymerization, a higher intrinsic viscosity of the raw polyethylene furanate is preferable. However, from the perspective of easily obtaining a raw polyethylene furanate with excellent color and low amounts of carboxylic acid termini and decarboxylation termini through short-time polycondensation reaction, and that subsequent solid-state polymerization can be carried out quickly, a lower intrinsic viscosity of the raw polyethylene furanate is preferable. Specifically, it is 0.65 dl / g or more, preferably 0.67 dl / g or more, and on the other hand, it is 0.85 dl / g or less, preferably 0.83 dl / g or less.

[0159] As described above, in order to obtain high-viscosity polyethylene furanate via solid-state polymerization, the amount of decarboxylation terminal groups generated by the decarboxylation reaction of furanyl dicarboxylic acid in the raw material polyethylene furanate is preferably low. Specifically, a polyester with a concentration typically below 20 eq / t, and preferably below 10 eq / t, is used. By keeping the amount of decarboxylation terminal groups in the raw material polyethylene furanate below a specific amount, the molecular weight increase caused by solid-state polymerization proceeds smoothly, and the viscosity of the polyethylene furanate can be sufficiently increased. It should be noted that the method for manufacturing raw material polyethylene furanate with a specific amount of decarboxylation terminal groups below is as described above.

[0160] Furthermore, using a raw material of polyethylene furanate with a lower amount of carboxyl-terminated groups than hydroxyl-terminated groups results in a faster solid-phase polymerization rate, which is therefore more preferable. The amount of carboxyl-terminated groups in the raw material polyethylene furanate is 5 eq / t or more, preferably 10 eq / t or more, and also 60 eq / t or less, preferably 50 eq / t or less. Here, the amount of hydroxyl-terminated groups is 30 eq / t or more, preferably 40 eq / t or more, and also 120 eq / t or less, preferably 100 eq / t or less. It should be noted that the method for manufacturing a raw material polyethylene furanate that satisfies these terminal group amounts is as described above.

[0161] Especially when obtaining poly(ethylene furanate) with high intrinsic viscosity, pre-crystallization is preferable before solid-state polymerization. Specifically, by carrying out solid-state polymerization at a temperature of about 190°C to about 210°C, the molecular weight of poly(ethylene furanate) increases, but it is preferable to gradually increase the temperature from about 100°C during the process of reaching this temperature range. Here, it is particularly preferable to crystallize the poly(ethylene furanate) by heating at 120°C for about 1 hour to about 6 hours. By making sufficient use of such a pre-crystallization time, thermal adhesion of particles, etc., is less likely to occur, allowing the subsequent solid-state polymerization reaction to proceed smoothly. If thermal adhesion occurs during pre-crystallization, it is preferable to perform a process of properly removing and dispersing the particles.

[0162] Intrinsic Viscosity

[0163] As described above, the method for manufacturing high-viscosity polyethylene furanate of this embodiment enables the production of polyethylene furanate with high intrinsic viscosity, which was previously unattainable. Therefore, the polyethylene furanate of this embodiment is preferably a high-viscosity polyethylene furanate with an intrinsic viscosity of 0.95 dl / g or higher. The intrinsic viscosity of the high-viscosity polyethylene furanate is preferably greater than 0.95 dl / g, more preferably 1.0 dl / g or higher, further preferably greater than 1.00 dl / g, and most preferably 1.1 dl / g or higher. Furthermore, it is preferably 1.5 dl / g or less, more preferably 1.3 dl / g or less. That is, the intrinsic viscosity of the polyethylene furanate of this embodiment is 0.95 dl / g or more, preferably 1.5 dl / g or less. By setting the intrinsic viscosity within such a range, a polyethylene furanate with excellent stretch formability and blow molding properties can be produced. Furthermore, as will be described later, when the polyethylene furanate of this embodiment is used in combination with other thermoplastic resins, from the viewpoint of easily improving oxygen barrier properties, a higher intrinsic viscosity is preferable.

[0164] By maintaining the intrinsic viscosity within the aforementioned range, molded articles exhibiting excellent strain curing properties, minimal thickness uniformity, and good impact resistance are readily obtained. Furthermore, molded articles with excellent impact resistance are particularly readily obtained when filled with liquids containing carbonic acid or subject to internal pressure. Additionally, due to the minimal thickness uniformity, uniform thin film formation is possible; therefore, by using the polyethylene furanate dicarboxylate of this embodiment, bottle weight reduction can be achieved, thus lessening environmental impact. Moreover, high pressure is not applied during molding, facilitating extrusion.

[0165] The reason why poly(ethylene furanate) readily exhibits strain-curing properties due to its high intrinsic viscosity is speculated as follows: Strain curing refers to the phenomenon where the viscosity of the resin increases significantly beyond its linear viscosity depending on the stretching speed. Typically, in stretching processes, stress concentrates in the thinner areas, causing deformation to progress and thickness unevenness to easily increase. However, strain-curing polymers, even when stretched, exhibit higher viscosity in the thinner areas, thus making the thickness more uniform and suitable for stretch forming processes.

[0166] <Strain Curing>

[0167] Strain curing properties can be quantified by the stress difference measured by tensile testing, as described later. The stress difference of the poly(ethylene furanate) in this embodiment is preferably 5 N / mm. 2 The above, and more preferably, is 8 N / mm 2 That's all. Furthermore, on the other hand, the stress difference is preferably 50 N / mm. 2 The following, or more preferably, is 40 N / mm 2 The following, and more preferably, is 30 N / mm 2 The following describes how strain curing properties are achieved by keeping the stress difference within the aforementioned range, enabling the production of bottles with uniform thickness via blow molding. Here, the strain curing properties can be adjusted by factors such as the polymerization temperature, polymerization time, and polymerization pressure during the manufacturing of polyethylene furanate. The strain curing properties of the polyethylene furanate of this embodiment can be adjusted using the same method as for adjusting the intrinsic viscosity of the polyethylene furanate described above.

[0168] <Glass transition temperature (Tg)>

[0169] The glass transition temperature of the polyethylene furanate in this embodiment is preferably 50°C or higher and 150°C or lower. More preferably, it is 60°C or higher. Furthermore, it is even more preferably 130°C or lower. By ensuring the glass transition temperature of the polyethylene furanate is within the above range, even if the contents of the bottle are foaming substances such as carbonated water, deformation caused by the pressure difference between the inside and outside of the bottle is less likely to occur. Furthermore, the bottle is less prone to deformation even when stored at high temperatures.

[0170] The glass transition temperature of the poly(ethylene furanate) in this embodiment can be adjusted by selecting other aliphatic diol components, etc.

[0171] The glass transition temperature can be determined using a differential scanning calorimeter according to the method in JIS K7121-1987. Specifically, polyethylene furanyl dicarboxylate is heated from 25°C to its melting point +30–60°C, then cooled to 25°C, and then heated again to its melting point +30–60°C. The heating and cooling rates are set to 10°C / min. The glass transition temperature at the midpoint of this second heating is taken as the glass transition temperature.

[0172] <Amount of decarboxylation terminal groups>

[0173] From the perspective of easily obtaining high-viscosity polyethylene furanate through solid-state polymerization, the amount of decarboxylation-terminated groups contained in the polyethylene furanate of this embodiment is preferably low. Specifically, it is preferably 20 eq / t or less, more preferably 10 eq / t or less. On the other hand, the amount of decarboxylation-terminated groups is generally 0.01 eq / t or more. The method for adjusting the amount of decarboxylation-terminated groups in the polyethylene furanate before solid-state polymerization is as described above. In addition, the amount of decarboxylation-terminated groups in the polyethylene furanate obtained by solid-state polymerization can be adjusted by the amount of decarboxylation-terminated groups contained in the raw polyethylene furanate before solid-state polymerization.

[0174] [Polyester Composition]

[0175] Another aspect of the present invention is a polyester composition containing the poly(ethylene furanate) of the present embodiment described above (hereinafter sometimes referred to as "the polyester composition of the present embodiment").

[0176] The polyester composition of this embodiment preferably contains polyethylene furanate dicarboxylate of this embodiment and other thermoplastic resins (hereinafter sometimes referred to as "other thermoplastic resins"). By containing polyethylene furanate dicarboxylate of this embodiment and other thermoplastic resins, strain curing properties are improved, and stretch forming can be easily performed.

[0177] <Other thermoplastic resins>

[0178] Other thermoplastic resins are thermoplastic resins other than polyethylene furanate used in this embodiment. Examples of other thermoplastic resins include other thermoplastic polyester resins (hereinafter sometimes referred to as "other polyesters") other than polyethylene furanate used in this embodiment, crosslinked thermoplastic resins, acrylic resins, polycarbonates, etc. Among these, at least one of other polyesters and crosslinked thermoplastic resins is preferred from the perspective of excellent strain curing properties.

[0179] In the polyester composition of this embodiment, the polyester of this embodiment is preferred from the viewpoint of excellent gas barrier properties and blow molding properties. On the other hand, other polyesters are preferred from the viewpoint of excellent strain curing properties and creep resistance.

[0180] These other thermoplastic resins can be used alone, or two or more can be used in any combination and ratio.

[0181] <Other Polyesters>

[0182] Other polyesters are polyesters having structural units derived from diols and structural units derived from dicarboxylic acids, and are polyesters other than the polyethylene furanate of this embodiment described above.

[0183] Examples of dicarboxylic acids that constitute dicarboxylic acid units in other polyesters include phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octylsuccinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, decamethyldicarboxylic acid, their anhydrides, and lower alkyl esters. Other polyesters preferably use structural units derived from dicarboxylic acids, other than these 2,5-furandicarboxylic acid units, as the main dicarboxylic acid units. Furthermore, it is particularly preferred to have terephthalic acid units as dicarboxylic acid units.

[0184] On the other hand, examples of diols constituting the diol units of other polyesters include 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), 1, Chain diols such as 2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, and polybutanediol; and cyclic diols such as 1,4-cyclohexanediol, 1,4-cyclohexanediol, 2,2-bis(4-hydroxycyclohexyl)propane, and epoxide adducts of 2,2-bis(4-hydroxycyclohexyl)propane, as well as aliphatic diols. Preferably, other polyesters have structural units derived from aliphatic diols as diol units, and more preferably have structural units derived from aliphatic chain diols.

[0185] <Cross-linked thermoplastic resins>

[0186] Strain curing properties can also be improved by using crosslinkable thermoplastic resins with functional groups capable of reacting with carboxyl and hydroxyl groups contained in polyester compositions. Examples of functional groups capable of reacting with carboxyl and hydroxyl groups include epoxy groups, etc. Functional groups such as zolylinoyl, carboxyl, and carbodiimide are preferred. These functional groups are located on the side chains of thermoplastic resins. By locating these functional groups on the side chains, a branched structure is formed, which slows down the elongation of molecules during stretching and improves strain curing properties.

[0187]

[0188] As a composition with particularly excellent gas barrier properties and blow molding properties, the polyethylene furanate of this embodiment is preferably more abundant 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 furanate, which contains thermoplastic resins other than the aforementioned polyethylene furanate. In the polyester composition of this embodiment, the polyethylene furanate of this embodiment preferably constitutes the largest proportion. Specifically, the content of polyethylene furanate of this embodiment in the polyester composition is generally 50% by weight or more, preferably 55% by weight or more, more preferably 60% by weight or more, further preferably 65% ​​by weight or more, and particularly preferably 70% by weight or more. It should be noted that the upper limit of the content of polyethylene furanate of this embodiment is 100% by weight, but from the viewpoint of easily exhibiting the effects brought about by the inclusion of other components, it is preferably 99% by weight or less, more preferably 95% by weight or less, and further preferably 90% by weight or less. That is, 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, and even more preferably 10% by weight or more. Furthermore, 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. Additionally, when the other thermoplastic resin is polyester, the content is particularly preferably 1% to 30% by weight, more preferably 5% to 30% by weight.

[0189] Furthermore, when the composition containing a large amount of the polyethylene furanate of this embodiment contains other thermoplastic resins, the other thermoplastic resins are preferably crosslinked thermoplastic resins or polyesters having at least one of the structural units of 1,4-butanediol units and polybutanediol units as diol units. The latter polyesters are particularly preferably those having 1,4-butanediol units, and even more preferably those having both 1,4-butanediol units and polybutanediol units. That is, the polyester composition of this embodiment contains a large amount of the polyethylene furanate of this embodiment, and also contains crosslinked thermoplastic resins and / or other thermoplastic polyester resins other than the polyethylene furanate of this embodiment. These other thermoplastic polyester resins preferably contain polyesters having terephthalic acid units as dicarboxylic acid units and having at least one of the structural units of 1,4-butanediol units and polybutanediol units as diol units; more preferably, they contain 50% by weight or more of the polyester of this embodiment.

[0190] When the composition containing a large amount of the polyester of this embodiment contains a crosslinked thermoplastic resin, a higher content is preferred from the viewpoint of excellent strain curing properties. On the other hand, a lower content is preferred from the viewpoint of reducing the likelihood of gelation and pitting, and facilitating a higher yield. Specifically, the crosslinked 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.

[0191] Thus, the polyester composition of this embodiment, by combining the polyethylene furanate of this embodiment with other polyesters, can exhibit sufficient strain curing properties even when the intrinsic viscosity and glass transition temperature of the polyester of this embodiment are outside the preferred range.

[0192] <Compositions with other thermoplastic resins as the main component>

[0193] In particular, as a composition with excellent strain curing and creep resistance, it is preferable that other thermoplastic resins are present in greater proportion than the polyethylene furanate in this embodiment. That is, in the polyester composition of this embodiment, other thermoplastic resins preferably constitute the largest proportion. Specifically, the content of other thermoplastic resins in this polyester composition is typically 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 other thermoplastic resins is preferably 99% by weight or less, and more preferably 95% by weight or less. Especially when the other thermoplastic resin is polyethylene terephthalate, the content of polyethylene terephthalate is preferably 80% by weight to 99% by weight.

[0194] From the perspective of excellent strain curing and tensile formability, the other thermoplastic resins contained in large quantities in this composition are preferably polyester resins, more preferably polyethylene terephthalate (PET) and polybutylene terephthalate. From the perspective of particularly easy improvement of the creep resistance of blow-molded bottles, polyethylene terephthalate is preferred, and from the perspective of particularly easy improvement of strain curing properties, polybutylene terephthalate is preferred.

[0195] From the perspective of easily exhibiting the improved gas barrier properties resulting from combined use, the small amount of polyethylene furanate dicarboxylate contained in this composition preferably has a particularly high intrinsic viscosity. Furthermore, the glass transition temperature is preferably within the aforementioned preferred range. Specifically, the small amount of polyethylene furanate dicarboxylate contained in this embodiment is a polyester having structural units derived from 2,5-furandicarboxylic acid and structural units derived from aliphatic diols, preferably with an intrinsic viscosity of 0.95 dl / g or more and 1.50 dl / g or less, more preferably with a glass transition temperature of 50°C or more and 150°C or less.

[0196] That is, another aspect of the present invention is a polyester composition containing polyethylene furanate with an intrinsic viscosity of 0.95 dl / g or more and 1.50 dl / g or less, and other thermoplastic resins. Furthermore, this polyester composition preferably contains 1 to 20% by weight of the polyethylene furanate and also contains polyethylene terephthalate.

[0197] <Additives>

[0198] In the manufacture of polyester compositions, various additives, such as heat stabilizers, antioxidants, hydrolytic agents, crystallizing nucleating agents, flame retardants, antistatic agents, mold release agents, and ultraviolet absorbers, can be used without impairing their properties.

[0199] These additives can be added to the reaction apparatus before the polymerization of the polyester, or to the conveying device from the start to the end of the polymerization reaction, or to the product after the polymerization reaction is completed and before extraction. Alternatively, they can be added to the extracted product.

[0200] In addition to the various additives mentioned above, impact modifiers, nucleating agents, reinforcing agents, and extenders can also be added during the molding of polyester compositions. When using additives, one type can be used alone, or two or more types can be used in any combination and ratio.

[0201] Impact Resistance Modifier

[0202] The polyester composition of this embodiment may contain an impact modifier. By containing an impact modifier, good mechanical properties can be achieved. The content of the impact modifier is preferably 0.01% by weight or more and 10% by weight or less.

[0203] Examples of impact-resistant modifiers include butadiene rubbers, acrylic rubbers, and silicone-acrylic composite rubbers. Among these, core-shell type impact modifiers are preferred, such as METABLEN (manufactured by Mitsubishi Chemical Corporation) and Kane Ace (manufactured by KANEKA Corporation).

[0204] Fillers can be used in the manufacture of polyester compositions. Fillers can be inorganic or organic. The content of fillers in the polyester composition can be selected within a range that satisfies the effect of filler addition while maintaining the tensile elongation and impact resistance of the polyester composition.

[0205] As inorganic fillers, examples include anhydrous silica, mica, talc, titanium dioxide, calcium carbonate, diatomaceous earth, diatomite, bentonite, potassium titanate, zeolite, sepiolite, montmorillonite, kaolin, glass, limestone, carbon, wollastonite, calcined perlite, calcium silicate, sodium silicate and other silicates, alumina, magnesium carbonate, calcium hydroxide and other hydroxides, iron carbonate, zinc oxide, iron oxide, aluminum phosphate, barium sulfate and other salts.

[0206] In the case of polyester compositions containing inorganic fillers, the content of inorganic fillers in the polyester composition is typically 1% by weight or more, preferably 3% by weight or more, and more preferably 5% by weight or more. Additionally, it is typically 80% by weight or less, preferably 70% by weight or less, and more preferably 60% by weight or less.

[0207] Examples of organic fillers include raw starch, processed starch, pulp, chitin / chitosan, coconut shell powder, bamboo powder, bark powder, and powders of kenaf or rice straw. Additionally, nanofibers such as cellulose, which are produced by decomposing pulp and other fibers to the nanoscale, can also be included.

[0208] In the case of polyester compositions containing organic fillers, the content of organic fillers in the polyester composition is typically 0.1% by weight or more, preferably 1% by weight or more. Furthermore, it is typically 70% by weight or less, preferably 50% by weight or less.

[0209] Examples of nucleating agents include glass fiber, carbon fiber, 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.

[0210] It should be noted that inorganic fillers added to improve rigidity and organic stabilizers added as heat stabilizers may also help promote crystallization. Additionally, inorganic or organic foreign matter mixed in during the polyester manufacturing or molding process can also act as crystal nucleating agents. Therefore, the crystal nucleating agents described in this specification refer to particles that are solid at room temperature and help promote crystallization.

[0211] The particle size of the nucleating agent is preferably small. The particle size of the nucleating agent is preferably 5 μm or less, more preferably 3 μm or less, further preferably 1 μm or less, and most preferably 0.5 μm or less. It should be noted that the lower limit of the particle size of the nucleating agent is typically 0.1 μm.

[0212] When a nucleating agent is used in the manufacture of a polyester composition, its amount relative to the polyester composition 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. Furthermore, the upper limit of the amount of the nucleating agent relative to the polyester composition is preferably 30% by weight, more preferably 10% by weight, even more preferably 5% by weight, and particularly preferably 1% by weight. By setting the amount of the nucleating agent within the above range, it tends to easily exhibit a crystallization-promoting effect, and also improves the mechanical properties and softness of the polyester composition.

[0213] <Method for manufacturing polyester composition>

[0214] The polyester composition of this embodiment can be manufactured using known methods. For example, it can be manufactured by melt-blending and granulating the raw materials using a single-screw extruder, a twin-screw extruder, a Banbury mixer, or the like.

[0215] <Strain Curing>

[0216] Regarding the strain-curing properties of the polyester composition of this embodiment, similarly to the case of the poly(ethylene furanate) of this embodiment described above, they can be quantified by the stress difference measured by the tensile test described later. The preferred range of the stress difference and the rationale for this are also explained for the poly(ethylene furanate) of this embodiment. That is, the stress difference is preferably 5 N / mm. 2 The above, and more preferably, is 8 N / mm 2 That's all. Furthermore, on the other hand, the stress difference is preferably 50 N / mm. 2 The following, or more preferably, is 40 N / mm 2 The following, and more preferably, is 30 N / mm 2The strain curing property is achieved by keeping the stress difference within the range described above, enabling the production of bottles with uniform thickness via blow molding. Here, the strain curing property can be adjusted by the type (especially intrinsic viscosity) and amount of polyester contained in the polyester composition, the polymerization temperature during manufacturing of each polyester, the polymerization time, and the pressure during the polymerization reaction. The strain curing property of the polyester composition of this embodiment is particularly improved by combining the poly(ethylene furanate) of this embodiment with other thermoplastic resins, and can be adjusted to a preferred range.

[0217] [Composition Confirmation Method]

[0218] The composition of the polyethylene furanate and polyester composition can be confirmed using conventionally known methods. For example, the composition can be separated into its constituent components using HPLC (high performance liquid chromatography), and then each component can be analyzed using NMR (nuclear magnetic resonance spectroscopy) or GC / MS (gas chromatography-mass spectrometry) after methanol decomposition to confirm its composition.

[0219] [Manufacturing method for polyester bottles]

[0220] The polyethylene furanate and polyester composition described in this embodiment is suitable for use 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; one example is shown below.

[0221] The manufacture of polyester bottles containing polyethylene furanate includes an injection molding process for producing a preform from the raw polyester and a blow molding process for producing a bottle from the preform. Here, the raw polyester preferably contains the polyethylene furanate of this embodiment. Furthermore, this manufacturing method is also suitable for cases where the raw polyester is the polyester composition of this embodiment.

[0222] In the manufacture of the bottle, firstly, polyethylene furanate or polyester composition, along with other additives as needed, is melt-blended and granulated using a single-screw extruder, twin-screw extruder, or Banbury mixer, or directly melt-blended during injection molding and then injected into a mold in the molten state, cooled, and removed, thereby forming a preform. When other thermoplastic resins are added, granulation is preferred for thorough mixing. The resin temperature in this extrusion process is not particularly limited, but from the perspective of formability and suppression of thermal degradation, a range of 210–290°C, and more preferably 230–270°C, is generally preferred.

[0223] Next, in the blow molding process, the preform is placed into a mold of the desired shape that has been heated to a specified temperature by a heater. Then, high-pressure air is blown in and the preform is mounted onto the mold, thereby forming the bottle.

[0224] 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.

[0225] [Polyester Bottle Making]

[0226] By using the polyethylene furanate and polyester composition of this embodiment, high-viscosity polyester bottles (hereinafter sometimes referred to as "high-viscosity bottles of this embodiment") can be obtained.

[0227] From the perspective of impact resistance, the intrinsic viscosity of the high-viscosity bottle of this embodiment is preferably high. However, from the perspective of ease of forming a bottle into the desired shape, the intrinsic viscosity of the high-viscosity bottle of this embodiment is preferably low. Therefore, specifically, it is preferably 0.75 dl / g or more, more preferably 0.85 dl / g or more, further preferably 0.90 dl / g or more, and particularly preferably 0.92 dl / g or more. Furthermore, it is preferably 1.2 dl / g or less, more preferably 1.15 dl / g or less. Here, regarding the intrinsic viscosity of the bottle, 0.25 g of the bottle flakes were dissolved in 50 ml of a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 50 / 50 (by weight), and the viscosity was measured using an Ubbelohde viscometer at 30°C. Here, the Huggins constant was set to 0.32.

[0228] From the perspective of creep resistance, the high-viscosity bottle of this embodiment preferably has a high degree of crystallinity. On the other hand, from the perspective of transparency, the high-viscosity bottle of this embodiment preferably has a low degree of crystallinity. Therefore, specifically, it is preferably 10% or more, more preferably 15% or more, more preferably 40% or less, more preferably 30% or less.

[0229] Regarding crystallinity, it can be determined by wide-angle X-ray diffraction using the following formula.

[0230] Crystallinity (%) = Peak area of ​​crystalline material / (Peak area of ​​crystalline material + Peak area of ​​amorphous material) × 100

[0231] By using the polyethylene furanate and polyester composition of this embodiment, bottles with excellent strain curing properties, minimal thickness uniformity, and good creep and impact resistance can be obtained. Blow-molded bottles manufactured using the polyethylene furanate and polyester composition of this embodiment are suitable for use as beverage bottles for alcoholic beverages, carbonated beverages, hot beverages, etc., due to their excellent gas barrier properties, creep resistance, and impact resistance. In other words, beverage products can be manufactured by filling beverages into the bottles (blow-molded bottles) of this embodiment.

[0232] Blow-molded bottles can be made into various shapes depending on the shape of the mold used. There are no particular limitations on the shape of blow-molded bottles; the key is that they can maintain the shape of the beverage. In particular, by molding with a uniform and sufficiently thick wall, suitable shapes are ideal for carbonated liquids such as beer and champagne, as well as hot beverages such as tea and coffee.

[0233] When these liquids are filled into bottles, the bottle opening is typically sealed with a resin cap or similar material, resulting in a higher internal pressure than external pressure. Therefore, to facilitate upright packing, transportation, and store display under this high internal pressure, the bottle bottom is preferably made into a pressure-resistant shape to suppress deformation caused by the internal pressure. Deformation of the bottle bottom and body is usually accompanied by creep (irreversible deformation caused by sustained stress), so the wall thickness and shape suitable for these bottles are common. Therefore, hereafter, bottles used for filling carbonated liquids or hot beverages are sometimes referred to as "heat-resistant pressure bottles." That is, the polyethylene furanate and polyester composition of this embodiment are suitable for heat-resistant pressure bottles.

[0234] The pressure-resistant shape of the bottom of the thermostable bottle can be, for example, a petal shape, a dome shape facing inwards (the so-called champagne bottom shape), or a shape with an uneven surface in the center of the bottom. A thicker average wall thickness reduces the likelihood of deformation or breakage caused by internal pressure. Specifically, while also depending 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. Furthermore, from the viewpoint of bottle formability, an average wall thickness of 0.70 mm or less is preferred.

[0235] By using the polyethylene furanate and polyester composition of this embodiment, wall thickness unevenness is reduced, and uniform film formation is possible, thereby obtaining a lightweight heat-resistant pressure vessel. Specifically, the weight / content of the vessel is preferably 10 g / L or more, more preferably 20 g / L or more, further preferably 30 g / L or more, particularly preferably 50 g / L or more, and on the other hand, preferably 200 g / L or less, more preferably 150 g / L or less, and particularly preferably 120 g / L or less.

[0236] Furthermore, by using the polyethylene furanate and polyester composition of this embodiment, a bottle with uniform thin walls and excellent gas barrier properties can be obtained. Therefore, the polyethylene furanate and polyester composition of this embodiment is particularly suitable for bottles used to fill carbonated liquids such as carbonated beverages. Additionally, blow-molded bottles manufactured using the polyethylene furanate and polyester composition of this embodiment exhibit excellent creep resistance and impact resistance when filled with carbonated liquids. Specifically, it is preferable to use it 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 preferably as a bottle for filling liquids containing 1 to 2 GV of carbon dioxide.

[0237] The polyethylene furanate and polyester composition of 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, due to its superior gas barrier properties compared to conventional PET bottles for alcoholic beverages, it can be used without a diamond-like carbon coating.

[0238] The polyethylene furanate of this embodiment has a glass transition temperature of 50°C or higher, making it less prone to deformation due to pressure differences between the inside and outside of the bottle. Therefore, it is suitable for bottles used to fill carbonated beverages and other foaming substances. Furthermore, since it is not easily deformed even when stored at high temperatures, it is also suitable for bottles used for hot beverages.

[0239] [Biaxially stretched film]

[0240] The polyethylene furanate and polyester compositions described in the embodiments of the present invention can be suitably used as biaxially stretched films. There are no particular limitations on their manufacturing methods; one example is shown below.

[0241] First, using polyethylene furanate or a polyester composition, the molten sheet extruded from the die is cooled and solidified by a cooling roller to obtain an unstretched sheet. In this case, to improve the flatness of the sheet, it is necessary to improve the adhesion between the sheet and the rotating cooling drum, preferably by using an electrostatic application method and / or a liquid coating method.

[0242] Next, the resulting unstretched sheet is stretched along a biaxial direction. In this case, firstly, the unstretched sheet is stretched in one direction using a stretching machine such as a roller or a tenter frame. The stretching temperature is typically 80–140°C, preferably 85–120°C, and the stretching ratio is typically 2.5–7 times, preferably 3.0–6 times. Then, a stretching temperature orthogonal to the stretching direction of the first stage is typically 70–170°C, and the stretching ratio is typically 3.0–7 times, preferably 3.5–6 times.

[0243] Then, heat treatment is performed at a temperature of 180–270°C under tension or with a relaxation of up to 30% to obtain a biaxially oriented film. During stretching, a method of stretching in one direction in two or more stages can also be used. In this case, it is preferable to ultimately achieve stretch ratios in both directions within the aforementioned ranges.

[0244] Alternatively, simultaneous biaxial stretching can be used in the manufacture of biaxially stretched films. Simultaneous biaxial stretching involves stretching the unstretched sheet simultaneously in two directions under a temperature controlled typically at 70–120°C, preferably 80–110°C. The stretching ratio, in terms of area ratio, is preferably 4–50 times, more preferably 7–35 times, and even more preferably 10–25 times. Then, the film is heat-treated at a temperature of 170–250°C under tension or with a relaxation of up to 30% to obtain a stretched oriented film. Regarding the simultaneous biaxial stretching apparatus using the above stretching method, conventionally known stretching methods such as screw-type, scaling-type, and linear drive-type stretching methods can be employed.

[0245] In the so-called coating stretching method (online coating) in which a primer coating and a hard coating are applied to the film surface during the stretching process of the biaxially stretched film, a coating liquid for forming a primer coating or a hard coating can be applied to the sheet after uniaxial stretching. When a primer coating and a hard coating are applied to the film using the coating stretching method, the coating can be performed simultaneously with stretching, and the thickness of the coating layer can be reduced according to the stretching ratio, thus enabling the manufacture of a film suitable for biaxial stretching.

[0246] Example

[0247] The following examples illustrate the invention in more detail, but the invention is not limited to the following examples as long as it does not depart from its spirit.

[0248] It should be noted that the evaluation methods in the following embodiments and comparative examples are as follows.

[0249] (1) Intrinsic viscosity of polyester

[0250] Accurately weigh 0.25 g of polyester and dissolve it in 50 ml of a 50 / 50 (by weight) mixed solvent of phenol and 1,1,2,2-tetrachloroethane. Measure the resulting solution using an Ubbelohde viscometer at 30 °C. The Huggins constant was set to 0.32.

[0251] (2) Glass transition temperature of polyester

[0252] The glass transition temperature was measured using a differential scanning calorimeter (DSC7000x, manufactured by Hitachi High Technology Co., Ltd.) according to the method specified in 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 / minute. The glass transition temperature at the midpoint of this second heating was taken as the glass transition temperature.

[0253] (3) Amount of terminal groups in polyester

[0254] The amounts of decarboxyl and hydroxyl terminal groups in polyester were quantified as follows: 20 mg of polyester was collected and dissolved in 1 g of a mixed solvent of deuterated chloroform / hexafluoroisopropanol d2 (2 / 1 weight ratio), and 60 μl of pyridine-d5 was further added. For this sample, the concentrations were determined using a 400 MHz NMR spectrometer manufactured by Brucker. 1 ¹H-NMR is used for quantification.

[0255] Specifically, by conducting 1 The amount of decarboxylation terminal groups and hydroxyl terminal groups of the polyester can be calculated using the following formula by H-NMR determination.

[0256] Amount of decarboxylation terminal groups (eq / t) = 4d / (182a+226c)×10 6

[0257] Amount of hydroxyl terminal groups (eq / t) = 2b / (182a+226c)×10 6

[0258] In the formula, a represents the cumulative peak value of the ethylene glycol structural unit, b represents the cumulative peak value of the hydroxyl-terminated group, c represents the cumulative peak value of the diethylene glycol structural unit, and d represents the cumulative peak value of the decarboxylation-terminated group. Additionally, in 1 In H-NMR, peaks of ethylene glycol were observed around 4.6–4.7 ppm, peaks of hydroxyl-terminal groups were observed around 3.97–4.0 ppm, peaks of diethylene glycol were observed around 3.88–3.9 ppm, and peaks of decarboxylation-terminal groups were observed around 6.53–6.5 ppm.

[0259] Furthermore, the amount of carboxyl-terminated groups was quantified using the following method. First, 0.3–0.4 g of polyester was accurately weighed, and 25 mL of benzyl alcohol was added. The mixture was stirred at 195°C for 7 minutes, and complete dissolution was visually confirmed. Next, the solution was cooled in an ice bath, and 2 mL of ethanol was added. Titration was performed using a 0.01 N NaOH benzyl alcohol solution using an automated titration apparatus “GT-200” manufactured by Mitsubishi Chemical Analytical Technology Co., Ltd. Here, the titration volume is set as A mL, and the blank value obtained by performing the same determination using only the solvent is set as B mL. Substituting these values ​​into the following calculation formula, the amount of carboxyl-terminated groups was calculated.

[0260] Amount of carboxyl-terminal groups (μeq / g) = (AB) × F × 10 / W

[0261] A[ml]: Measurement volume of titrant

[0262] B[ml]: Blank titration amount

[0263] F: Factor of 0.01N NaOH benzyl alcohol solution

[0264] W[g]: Sample weight

[0265] (4) Stress difference based on tensile test (strain curing)

[0266] Tensile tests were conducted under the following conditions based on JIS K7127. The difference between the stress at 100% elongation and the maximum stress was taken as the stress difference. The stress difference was set to 5 N / mm. 2 The above conditions are set as good.

[0267] Device: AG-1000ARI (manufactured by Shimadzu Corporation)

[0268] Sample dimensions: 15mm width × 70mm length × 200μm thickness

[0269] Tensile temperature: 90℃

[0270] Chuck spacing: 30mm

[0271] Distance between markings: 30mm

[0272] Stretching speed: 200mm / minute

[0273] Extension distance: 160mm

[0274] (5) Blow molding properties

[0275] Blow molding performance is evaluated based on the yield (forming success rate) when blow molding preforms for bottles using a blow molding machine (FRB-1 manufactured by FRONTIER). A yield rate of 100% is set as 0, and a yield rate of less than 95% is set as ×.

[0276] (6) Gas barrier properties (oxygen permeability)

[0277] The oxygen permeability of blow-molded bottles was measured using an oxygen permeability measuring device (MODERNCONTROL OX-TRAN2 / 21). Regarding oxygen permeability, the temperature was adjusted for 12 hours from the start of the measurement at 23°C and 90% RH, and the value after 72 hours was taken as the oxygen permeability. The oxygen permeability of a general-purpose PET bottle (the 100% polyester (G) bottle obtained in Reference Example 3 described later) was set to 1, and the relative oxygen barrier properties were evaluated. Regarding oxygen barrier properties, a relative evaluation greater than 1 was considered good. A relative evaluation of 5 or higher is particularly preferred because it eliminates the need for the diamond-like carbon coating applied to conventional PET bottles to improve gas barrier properties, which is essential for ensuring oxygen barrier properties in wine bottle applications.

[0278] (7) Creep resistance

[0279] Fill blow-molded bottles with 2.8 GV of carbonated water and cap them. Immerse the bottles in warm water at 40°C for 1 hour. After the samples are cooled to room temperature, measure the bottle dimensions (total height: height from top to bottom, bottle diameter: circumference of the widest part of the bottle, capacity: volume of the bottle). For the rate of change, mark ◎ if it is smaller than that of a standard PET bottle, 〇 if it is equal to that of a standard PET bottle, and × if it is larger than that of a standard PET bottle. It should be noted that 1 GV is a unit representing the state of 1 L of carbon dioxide dissolved in 1 L of liquid under standard conditions.

[0280] (8) Impact resistance test

[0281] <Water Filling>

[0282] Fill a blow-molded bottle with distilled water and cap it. After cooling to 5°C, drop it three times consecutively from a height of 80cm in an upright position (cap side up). For the same sample, drop it three times consecutively in an inverted position (cap side down). After the test, mark 0 if there is no leakage of the contents, △ if the bottle is deformed, and × if there is leakage.

[0283] <Carbonated water filling>

[0284] The bottles for which creep resistance was evaluated were cooled to 5°C and subjected to drop tests in the same manner as those filled with water to evaluate impact resistance.

[0285] (9) Reaction rate of esterification reaction

[0286] Collect the reaction solution just before depressurization (before entering the polycondensation process) and use... 1 The reaction was analyzed by H-NMR to determine the esterification rate. Specifically, 10–20 mg of the reaction solution was collected, dissolved in 1 g of dimethyl sulfoxide-d6, and measured using a 400 MHz NMR spectrometer manufactured by Bruker.

[0287] (10) Crystallinity of the bottle

[0288] Wide-angle X-ray diffraction was measured to calculate the crystallinity. Wide-angle X-ray diffraction was performed using a "NANO-Viewer" (manufactured by Rigaku Corporation) at an X-ray source of CuKα (λ = 0.154 nm), a camera length of 74.7 mm, an irradiation time of 45 minutes, and a temperature of 25°C. The crystallinity was calculated by fitting the spectrum obtained from the wide-angle X-ray diffraction measurements to the following formula.

[0289] Crystallinity (%) = Peak area of ​​crystalline material / (Peak area of ​​crystalline material + Peak area of ​​amorphous material) × 100

[0290] [Reference Example 1]

[0291] 85.7 g of 2,5-furandicarboxylic acid (manufactured by V&V PHARMA INDUSTRIES), 68.16 g of 1,2-ethylene glycol (manufactured by Mitsubishi Chemical), and 0.029 g of tetraethylammonium hydroxide 35% aqueous solution were added to a reaction vessel equipped with a stirring device, a nitrogen inlet, a heating device, a thermometer, and a pressure reducing port, so that the reaction vessel was filled with a nitrogen atmosphere.

[0292] Next, the reaction vessel was immersed in an oil bath set at 120°C. While stirring, the temperature was increased to 210°C over 60 minutes and maintained at 210°C for 200 minutes. The distillate was then recovered for esterification. A portion of the reaction solution was collected and analyzed using NMR, revealing an esterification rate of 92%.

[0293] Next, 0.71 g of a 1,2-ethylene glycol solution containing 5.0 wt% tetrabutyl titanate was added to the reaction solution after the esterification reaction (the molar ratio of Ti to 2,5-furandicarboxylic acid was 0.00019 mol, and the Ti concentration relative to the generated polyester was 50 ppm). The temperature was raised to 260°C over 1.5 hours, while the pressure was gradually reduced from atmospheric pressure to approximately 130 Pa over the same period of time, and then maintained at 130 Pa. After 3 hours and 46 minutes from the start of the decompression, stirring was stopped, and the pressure was restored to end the polycondensation reaction. The produced polyester was drawn out from the bottom of the reaction tank in a strand, cooled in a cooling water bath, and then cut using a granulator to obtain polyester (I) granules of approximately 2 mm to approximately 3 mm square. The intrinsic viscosity of polyester (I) was 0.78 dL / g. In addition, regarding the amount of terminal groups, the carboxyl terminal group is 23 eq / t, the hydroxyl terminal group is 71 eq / t, the decarboxyl terminal group is 4 eq / t, and the ratio of the amount of decarboxyl terminal group to the total amount of decarboxyl terminal group and carboxyl terminal group is 0.14.

[0294] [Reference Example 2]

[0295] The holding time at 210°C in the esterification reaction was changed from 200 minutes to 75 minutes, and otherwise carried out in the same manner as in Reference Example 1, to obtain polyester (J). Here, the esterification reaction rate was 83%. Furthermore, the intrinsic viscosity of polyester (J) was 0.81 dL / g, and regarding the amount of its terminal groups, the carboxyl-terminal groups were 19 eq / t, the hydroxyl-terminal groups were 38 eq / t, the decarboxylation-terminal groups were 29 eq / t, and the ratio of the amount of decarboxylation-terminal groups to the sum of the amounts of decarboxylation-terminal groups and carboxyl-terminal groups was 0.60. The results of Reference Examples 1 and 2 are summarized in Table 1.

[0296] [Table 1]

[0297] Table 1

[0298] Reference Example 1 See Example 2 Heating time at 210°C in esterification reaction 200 minutes 75 minutes esterification reaction rate 92％ 83％ Amount of decarboxylation terminal groups in polyester [eq / t] 4 29

[0299] Table 1 confirms that by conducting the esterification reaction for a longer time, and ensuring that the esterification is complete, polyethylene furanate with a reduced amount of decarboxylation terminal groups can be obtained.

[0300] [Example A1]

[0301] <Meltion Polymerization>

[0302] 42.85 kg of 2,5-furandicarboxylic acid (manufactured by V&V PHARMA INDUSTRIES), 30.6 L of 1,2-ethylene glycol (manufactured by Mitsubishi Chemical), and 14.3 g of tetraethylammonium hydroxide 35% aqueous solution were added to a reaction vessel equipped with a stirring device, nitrogen inlet, heating device, thermometer, and distillation column, so that the reaction vessel was filled with a nitrogen atmosphere.

[0303] Next, while stirring, the temperature was raised to 200°C over 2 hours and maintained at 200°C for 2 hours and 30 minutes. The distillate was then recovered and the esterification reaction was carried out (the total heating time was 4 hours and 30 minutes).

[0304] Next, the reaction solution was transferred to a reactor equipped with a pressure reducing port and a stirring device. 888.5 g of a 1,2-ethylene glycol solution containing 2.0 wt% tetrabutyl titanate was added, and stirring was initiated (the molar ratio of Ti to 2,5-furandicarboxylic acid was 0.00019 mol, and the Ti concentration relative to the generated polyester was 50 ppm). The temperature was raised to 260°C over 2 hours, while 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 pressure reduction, stirring was stopped, the pressure was restored, and the polycondensation reaction was terminated. The produced polyester was extracted from the bottom of the reaction tank in a strand, cooled in a cooling water bath, and then cut using a granulator to obtain polyester (A) granules approximately 2 mm to 3 mm square. The intrinsic viscosity of polyester (A) was 0.74 dL / g. In addition, regarding the amount of terminal groups, the carboxyl terminal group is 29 eq / t, the hydroxyl terminal group is 51 eq / t, the decarboxyl terminal group is 5 eq / t, and the ratio of the amount of decarboxyl terminal group to the total amount of decarboxyl terminal group and carboxyl terminal group is 0.14.

[0305] Solid-phase polymerization

[0306] For polyester (A), pre-crystallization is performed by introducing nitrogen gas at a flow rate of 30 L / min while heating. Specifically, 10 kg of polyester (A) is placed in an inert oven (Yamato Scientific "DN411I"), heated at 120°C for 3 hours, and then cooled to room temperature (25°C) to separate the thermally bonded particles. Again, the particles are heated at 150°C for 3 hours, cooled to room temperature (25°C), and then the thermally bonded particles are separated.

[0307] Next, 10 kg of the pre-crystallized polyester (A) was placed in the aforementioned inert oven and heated sequentially at 120°C for 1 hour, 150°C for 1 hour, 180°C for 3 hours, and 200°C for 18 hours under nitrogen gas at a flow rate of 30 L / min, thereby undergoing solid-state polymerization to obtain polyester (B). The intrinsic viscosity of polyester (B) is 1.02 dL / g, and the glass transition temperature is 81.2°C.

[0308] The strain curing properties were evaluated by performing tensile tests on polyester (B). Specifically, a surface-released metal frame (SUS304, outer diameter 110mm, inner diameter 70mm, thickness 0.2mm) was placed on a 150mm × 150mm PTFE strip (Naflon Tape (registered trademark) BTOMBO No. 9001, thickness 0.05mm, manufactured by Nigas Corporation). 2.0g of polyester (B) was measured inside the metal frame, and the 150mm × 150mm PTFE strip was further placed on top of it. With the polyester (B) held between two 160mm × 160mm, 3mm thick iron plates, a hot press (IMC-180C type, manufactured by Imoto Manufacturing Co., Ltd.) was used to hot press the PTFE strip between two iron plates, thereby obtaining a 70mm × 70mm × 0.2mm thick hot press sheet. The hot pressing temperature is 280℃, and the hot pressing time is 1 minute of preheating and 1 minute of pressing.

[0309] The PEFE strip was peeled from the obtained hot-pressed sheet and evaluated by tensile testing. The results are shown in Table 2, exhibiting good strain curing properties. Since the strain curing properties are similar to those of polyesters (C) and (D) described later, it is considered suitable for blow molding.

[0310] [Example A2]

[0311] For Example A1, the heating time at 200°C during the final stage of solid-state polymerization was changed from 18 hours to 24 hours, otherwise the process was the same as in Example A1, yielding polyester (C) with an intrinsic viscosity of 1.12 dl / g, a decarboxylation terminal group content of 8 eq / t, and a glass transition temperature of 82.6°C. The obtained polyester (C) was then subjected to the same hot-pressing and tensile testing processes as in Example A1. The results are shown in Table 2, demonstrating good strain-curing properties. Furthermore, the blow molding properties of the polyester (C) were good, as described later in Example B1.

[0312] [Example A3]

[0313] For Example A1, the heating time at 200°C during the final stage of solid-state polymerization was changed from 18 hours to 40 hours, otherwise the process was the same as in Example A1, yielding polyester (D) with an intrinsic viscosity of 1.23 dl / g and a glass transition temperature of 83.1°C. The obtained polyester (D) was then subjected to the same hot-pressing and tensile testing processes as in Example A1. The results are shown in Table 2, demonstrating good strain-curing properties. Furthermore, the blow molding properties of polyester (D) were good, as described later in Example B2.

[0314] [Comparative Example A1]

[0315] For Example A1, polyester (A) was used instead of polyester (B), and the process was otherwise the same as in Example A1, with hot-pressed sheets prepared and tensile tests performed. The results are shown in Table 2, indicating insufficient strain curing. Furthermore, as shown in Comparative Example B1 described later, it was confirmed that it was not suitable for blow molding.

[0316] [Example A4]

[0317] Using a small mixer (Xplore Instruments, Xplore series MC15), 11.25g of polyester (A) and 3.75g of polyester (E) as shown below were fed from the hopper as raw materials. After mixing for 5 minutes at 100 rpm, 240°C and nitrogen atmosphere, the mixed resin was recovered from the purge hole, thereby obtaining the polyester composition strands.

[0318] The obtained polyester composition strands were hot-pressed in the same manner as in Example A1, except that the hot-pressing temperature was 260°C, thereby producing hot-pressed sheets. Tensile tests were performed on the obtained hot-pressed sheets. The results, shown in Table 2, indicate good strain curing properties.

[0319] • Polyester (E): A homopolymer polyester resin of terephthalic acid and 1,4-butanediol manufactured by Mitsubishi Engineering Plastics Co., Ltd. under the trade name "NOVADURAN 5020".

[0320] [Examples A5-A8]

[0321] For Example A4, the resin formulation was changed to the formulation shown in Table 2, and otherwise the same procedure was followed as in Example A4 to obtain a polyester composition. Hot-pressed sheets were then manufactured, and tensile tests were performed on each hot-pressed sheet. The results, as shown in Table 2, all exhibited good strain-curing properties. Therefore, it is presumed to be suitable for blow molding.

[0322] It should be noted that the following table shows the details of the resins.

[0323] • Polyester (F): A copolyester resin of terephthalic acid, 1,4-butanediol, and polybutanediol (PTMG) manufactured by Mitsubishi Engineering Plastics Co., Ltd.

[0324] • Crosslinked thermoplastic resin (A): A styrene-acrylic polymer containing epoxy groups, manufactured by Nippon Oil Co., Ltd. under the trade name "MARPROOF G-0250SF". Mw: 20000, Tg: 74℃, epoxy equivalent: 310g / eq.

[0325] • Crosslinked thermoplastic resin (B): Trade name "EPOCROS RPS-1005" manufactured by Nippon Shokubai Co., Ltd. Azoline-modified polystyrene.

[0326] The results of Examples A1 to A8 and Comparative Example A1 are summarized in Table 2.

[0327] [Table 2]

[0328] Table 2

[0329]

[0330] Based on the results summarized in Table 2, the following situations are identified.

[0331] A comparison of Examples A1 to A3 with Comparative Example A1 confirmed that polyethylene furanate dicarboxylate, which has structural units derived from 2,5-furandicarboxylic acid and structural units derived from 1,2-ethylene glycol and has a high intrinsic viscosity, exhibits excellent strain curing properties. It can be made thin and uniform by blow molding or stretching, making it suitable for blow-molded bottle applications and biaxial stretch film applications.

[0332] Furthermore, a comparison of Examples A4 to A8 with Comparative Example A1 confirms that polyethylene furanate having structural units derived from 2,5-furandicarboxylic acid and structural units derived from 1,2-ethylene glycol, when combined with a small amount of other thermoplastic resins, exhibits significantly improved strain curability. It can be blow-molded or stretched into thin and uniform sheets, making it suitable for blow-molded bottle applications and biaxial stretch film applications.

[0333] It should be noted that the polyester and the polyester composition of this embodiment are easy to form thin and uniformly, such as... Figure 1 As shown, it is speculated that the higher the intrinsic viscosity of the polyester, the higher the strain curing property.

[0334] In addition, the results of stroke-stress measurements of these polyesters will be presented in... Figure 1 middle. Figure 1 The measurement was conducted under the same conditions as the stress difference determination based on tensile testing described above. Figure 1It is known that polyesters with high intrinsic viscosity experience increased stress with stretching, making them suitable for stretching. Furthermore, compositions incorporating other thermoplastic resins also exhibit increased stress, thus making them suitable for stretching.

[0335] [Comparative Example A2]

[0336] <Meltion Polymerization>

[0337] 42.85 kg of 2,5-furandicarboxylic acid, 30.6 L of 1,2-ethylene glycol, and 14.3 g of a 35% by weight aqueous solution of tetraethylammonium hydroxide were added to a reaction vessel equipped with a stirring device, nitrogen inlet, heating device, thermometer, and distillation column, creating a nitrogen atmosphere inside the reaction vessel. Then, while stirring, the temperature was raised to 210 °C over 2 hours and maintained at 210 °C for 30 minutes. The distillate was then recovered, and the esterification reaction was carried out (total heating time: 2 hours and 30 minutes).

[0338] Next, the reaction solution was transferred to a reactor equipped with a pressure reducing port and a stirring device. 888.5 g of a 1,2-ethylene glycol solution containing 2.0 wt% tetrabutyl titanate (Ti to 2,5-furandicarboxylic acid molar ratio of 0.00019 mol) was added, and stirring was initiated (Ti concentration relative to the generated polyester was 50 ppm). The temperature was raised to 260 °C over 1.5 hours, while the pressure was gradually reduced from atmospheric pressure to approximately 130 Pa over the same period, and then maintained at 130 Pa. After 2 hours and 47 minutes from the start of pressure reduction, stirring was stopped, the pressure was restored, and the polycondensation reaction was terminated. The produced polyester was extracted from the bottom of the reaction tank in a strand, cooled in a cooling water bath, and then cut using a granulator to obtain polyester (a) granules approximately 2 mm to 3 mm square. The intrinsic viscosity of polyester (a) was 0.61 dL / g. In addition, regarding the amount of terminal groups, the carboxyl terminal group is 21 eq / t, the hydroxyl terminal group is 58 eq / t, the decarboxyl terminal group is 34 eq / t, and the ratio of the amount of decarboxyl terminal group to the total amount of decarboxyl terminal group and carboxyl terminal group is 0.61.

[0339] [Comparative Example A3]

[0340] Polyester (a) was used instead of polyester (A), and pre-crystallization and solid-state polymerization were performed in the same manner as in Example A1, thereby obtaining polyester (b). Polyester (b) has an intrinsic viscosity of 0.73 dL / g and a decarboxylation end group amount of 42 eq / t.

[0341] [Comparative Example A4]

[0342] For Comparative Example A3, the heating time at 200°C at the end of the solid-state polymerization was changed from 18 hours to 24 hours, and otherwise the same procedure was performed as in Comparative Example A3, resulting in a polyester (c) with an intrinsic viscosity of 0.74 dl / g.

[0343] [Comparative Example A5]

[0344] For Comparative Example A3, the heating time at 200°C at the end of the solid-state polymerization was changed from 18 hours to 36 hours, and otherwise the same procedure was performed as in Comparative Example A3, resulting in a polyester (d) with an intrinsic viscosity of 0.76 dl / g.

[0345] For Examples A1 to A3, Comparative Examples A3 to A5, and Comparative Example B3 (described later), the results of reaction conditions, intrinsic viscosity, and amount of terminal groups are summarized in Tables 3-1 to 3-3.

[0346] [Table 3-1]

[0347] Table 3-1

[0348]

[0349] [Table 3-2]

[0350] Table 3-2

[0351]

[0352] A: Amount of hydroxyl terminal groups

[0353] B: Amount of carboxyl-terminal groups

[0354] C: Amount of decarboxylation terminal groups

[0355] [Table 3-3]

[0356] Table 3-3

[0357]

[0358] The results summarized in Tables 3-1 to 3-3 confirm that esterification is fully carried out by conducting the esterification reaction at low temperature for a long time, and polyesters with reduced decarboxylation terminal groups can be obtained by using titanium catalysts for polycondensation reaction. High-viscosity polyesters can be obtained by solid-state polymerization.

[0359] [Example B1]

[0360] Preforms for bottles were manufactured using polyester (C) as the raw material. The preforms were blow-molded using a blow molding machine (FRB-1 manufactured by FRONTIER), resulting in blow-molded bottles with a capacity of 350ml, a weight of 29g, a weight / capacity ratio of 82g / L, an average wall thickness of 0.26mm, and a petal-shaped bottom. The yield rate during blow molding was 100%. The resulting bottles had an intrinsic viscosity of 0.92dl / g and a crystallinity of 16%. Furthermore, due to the petal-shaped bottom, the bottles are suitable for heat-resistant pressure vessels used for carbonated liquids or hot beverages, exhibiting high oxygen barrier properties, excellent creep resistance, and impact resistance.

[0361] [Example B2]

[0362] Polyester (D) was used instead of polyester (C) as the raw material, and the process was otherwise identical to that in Example B1 to obtain a blow-molded bottle (heat-resistant pressure bottle). The yield rate during blow molding was 100%. The resulting bottle had an intrinsic viscosity of 0.99 dl / g and a crystallinity of 19%. Furthermore, the resulting bottle exhibited high oxygen barrier properties and excellent impact resistance. In addition, its creep resistance was superior to that of general-purpose PET bottles.

[0363] [Examples B3-B7]

[0364] The raw polyester was used in the proportions shown in Table 4, otherwise the process was the same as in Example B1, to obtain blow-molded bottles (heat-resistant bottles). The yield rate during blow molding was 100%. The resulting bottles had oxygen barrier properties equivalent to those of general-purpose PET bottles and excellent impact resistance. Furthermore, their creep resistance was superior to that of general-purpose PET bottles.

[0365] • Polyester (G): Polyethylene terephthalate manufactured by Mitsubishi Chemical Corporation, trade name "Nobapex BK2180", intrinsic viscosity is 0.83 dl / g.

[0366] [Example B8]

[0367] Polyester (B) was used instead of polyester (C) as the raw material, and the process was otherwise the same as in Example B1 to obtain a blow-molded bottle (heat-resistant bottle). The yield rate during blow molding was 100%. In addition, the impact resistance of the obtained bottle was better than that of Comparative Examples B1 and B2 described later. Furthermore, its creep resistance was also better than that of general-purpose PET bottles.

[0368] [Comparative Example B1]

[0369] Polyester (A) was used instead of polyester (C) as the raw material, and the process was otherwise the same as in Example B1 to obtain a blow-molded bottle. The yield rate during blow molding was less than 95%. In addition, the resulting bottle had poor impact resistance and creep resistance.

[0370] [Comparative Example B2]

[0371] For Example A1, the heating time at 200°C at the end of the solid-state polymerization was changed from 18 hours to 6 hours, and otherwise the same as in Example A1 was performed to obtain polyester (H) with an intrinsic viscosity of 0.85 dl / g.

[0372] Polyester (H) was used instead of polyester (C) as the raw material, and the process was otherwise the same as in Example B1 to obtain a blow-molded bottle. The yield rate during blow molding was 100%. However, the resulting bottle had poor impact resistance and creep resistance.

[0373] [Comparative Example B3]

[0374] For Example A1, the heating time at 200°C at the end of the solid-state polymerization was changed from 18 hours to 9 hours, and otherwise the same procedure was followed as in Example A1, resulting in a polyester (K) with an intrinsic viscosity of 0.92 dl / g.

[0375] Polyester (K) was used instead of polyester (C) as the raw material, and the process was otherwise the same as in Example B1 to obtain a blow-molded bottle. The yield rate during blow molding was 100%. However, the resulting bottle had poor impact resistance.

[0376] [Comparative Example B4]

[0377] The raw polyester was used in the proportions shown in Table 4, otherwise the process was the same as in Example B1, to obtain blow-molded bottles (heat-resistant bottles). The yield rate during blow molding was 100%. However, the resulting bottles had poor impact resistance and creep resistance.

[0378] [Example B9]

[0379] The proportion of raw polyester was the same as in Example A6, and otherwise the same as in Example B1 was performed to obtain a blow-molded bottle (heat-resistant pressure bottle). The yield rate during blow molding was 100%.

[0380] [Reference Example 3] Manufacturing of General Purpose PET 100% Bottles

[0381] Polyester (G) was used instead of polyester (C) as the raw material, and the process was otherwise the same as in Example B1 to obtain blow-molded bottles. The properties of the resulting bottles are shown in Table 4.

[0382] The results of Examples B1 to B8, Comparative Examples B1 to B4, and Reference Example 3 are summarized in Table 4.

[0383] [Table 4]

[0384] Table 4

[0385]

[0386] Based on the results summarized in Table 4, the following situations are identified.

[0387] A comparison of Examples B1, B2, and B8 with Comparative Examples B1 to B3 confirms that, although an intrinsic viscosity of 0.7 dL / g is generally considered good for PET bottles, the intrinsic viscosity of the polyester of this embodiment is much higher, making it suitable for blow-molded bottle applications. In particular, blow-molded bottles made using the polyester of this embodiment, despite their low weight-to-volume ratio, thinness, and lightness, are suitable for filling liquids such as wine that are easily oxidized by air due to their high oxygen barrier properties. Furthermore, they exhibit high creep resistance and impact resistance even when filled with highly concentrated carbonated water, making them suitable for filling carbonated beverages and other carbonated liquids. Moreover, the polyester of this embodiment, by containing structural units derived from 2,5-furandicarboxylic acid, has a high glass transition temperature and excellent heat resistance, making it suitable for use as a bottle for hot beverages. It should be noted that the polyester of this embodiment has good blow-molding properties; by using this polyester, blow-molded bottles with excellent oxygen barrier properties, impact resistance, and creep resistance are obtained. This is believed to be due to factors such as… Figure 1 As shown, the higher the intrinsic viscosity of polyester, the higher its strain curing property, which enables the formation of more uniform and thinner bottles.

[0388] Furthermore, a comparison between Examples B3 to B7 and Comparative Example B4 confirmed that by combining polyethylene terephthalate with a polyester having structural units derived from 2,5-furandicarboxylic acid and structural units derived from aliphatic diols and possessing high intrinsic viscosity, blow molding properties are improved, and the oxygen barrier properties and creep resistance of polyethylene terephthalate can be enhanced. Therefore, blow-molded bottles manufactured using the polyester of this embodiment are heat-resistant pressure bottles with excellent gas barrier properties, creep resistance, heat resistance, and impact resistance, suitable for applications such as filling hot beverages, filling carbonated liquids, and filling alcoholic liquids.

[0389] [Reference Example 4]

[0390] The following raw materials were added to a reaction vessel equipped with a stirring device, a nitrogen inlet, a heating device, a thermometer, and a pressure reducing port: 85.7 g of 2,5-furandicarboxylic acid (manufactured by V&V PHARMA INDUSTRIES), 68.16 g of 1,2-ethylene glycol (manufactured by Mitsubishi Chemical), 0.036 g of antimony trioxide (Sb2O2) (with an Sb concentration of 300 ppm relative to the generated polyester), and 0.029 g of a 35% by weight aqueous solution of tetraethylammonium hydroxide, so that the reaction vessel was under a nitrogen atmosphere.

[0391] Next, the reaction vessel was immersed in an oil bath set at 120°C. While stirring, the temperature was increased to 210°C over 60 minutes and maintained at 210°C for 200 minutes. The distillate was then recovered for esterification. A portion of the reaction solution was collected and analyzed using nuclear magnetic resonance spectroscopy. The results showed that the esterification rate was 94%.

[0392] Next, the temperature was raised to 260°C over 1.5 hours, while the pressure was gradually reduced from atmospheric pressure to approximately 130 Pa over the same period of time, and then maintained at 130 Pa. Six hours after the start of the decompression, stirring was stopped, the pressure was restored, and the polycondensation reaction was terminated. The produced polyester was then drawn out in strands from the bottom of the reaction tank, cooled in a cooling water bath, and cut using a granulator to obtain polyester (K) granules approximately 2 mm to 3 mm square. The intrinsic viscosity of polyester (K) was 0.65 dL / g. Furthermore, regarding the amount of terminal groups, the carboxyl-terminated groups were 12 eq / t, the hydroxyl-terminated groups were 97 eq / t, the decarboxylated groups were 12 eq / t, and the ratio of the amount of decarboxylated terminal groups to the total amount of decarboxylated and carboxyl-terminated groups was 0.5.

[0393] For the polyesters (I) to (K) obtained in Reference Examples 1, 2, and 4, an attempt was made to increase the molecular weight through solid-state polymerization. 10 g of granules were placed in an inert oven and heated at 120°C for 6 hours with nitrogen at a flow rate of 30 L / min. Then, after cooling to room temperature (25°C), the thermally bonded granules were dispersed. Furthermore, these granules were heated at 150°C for 3 hours, at 180°C for 3 hours, and at 200°C for 9 hours to carry out solid-state polymerization. The intrinsic viscosity of the solid-state polymerized polyester is shown in Table 5.

[0394] [Table 5]

[0395] Table 5

[0396]

[0397] A: Amount of hydroxyl terminal groups

[0398] B: Amount of carboxyl-terminal groups

[0399] C: Amount of decarboxylation terminal groups

[0400] Table 5 shows that the solid-state polymerization rate slows down when the amount of decarboxylation-terminated (C) groups is high, or when the ratio of the amount of decarboxylation-terminated groups to the total amount of decarboxylation-terminated and carboxyl-terminated groups (C / (B+C)) exceeds 0.5. It also indicates that titanium catalysts promote faster polymerization compared to antimony catalysts.

Claims

1. A poly(ethylene furanate) having an intrinsic viscosity of 1.1 dl / g or higher and 1.50 dl / g or lower, as determined by the following method. 0.25 g of polyethylene furanate was dissolved in 50 ml of a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (by weight) in a ratio of 50 / 50. The viscosity was measured using an Ubbelohde viscometer at 30 °C, with the Huggins constant set to 0.

32. The poly(ethylene furanate) is obtained by the following method for manufacturing high-viscosity polyethylene furanate. The manufacturing method includes a polyurethane dicarboxylate raw material manufacturing step using a titanium catalyst to manufacture the raw material polyurethane dicarboxylate, and a solid-phase polymerization step of subjecting the raw material polyurethane dicarboxylate to solid-phase polymerization. The intrinsic viscosity of the raw material, polyethylene furanate dicarboxylate, as determined by the following method, is ≥0.65 dl / g and ≤0.85 dl / g, and the amount of decarboxylation terminal groups in the following formula is ≤20 eq / t. 0.25 g of polyethylene furanate was dissolved in 50 ml of a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (by weight) in a ratio of 50 / 50. The viscosity was measured using an Ubbelohde viscometer at 30 °C, with the Huggins constant set to 0.

32. 。 2. The polyethylene furanate as described in claim 1, wherein, The poly(ethylene furanate) contains 1 to 100 ppm of titanium atoms.

3. The polyethylene furanate as described in claim 1 or 2, used for blow-molded bottles.

4. A bottle made of polyethylene furanate dicarboxylate, wherein the intrinsic viscosity, as determined by the following method, is ≥0.75 dl / g and ≤1.2 dl / g. 0.25 g of the tablet was dissolved in 50 ml of a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (by weight, 50 / 50). The solution was measured using an Ubbelohde viscometer at 30 °C, with the Huggins constant set to 0.

32. The poly(ethylene furanate) bottle is made from any one of the poly(ethylene furanate) according to claims 1 to 3.

5. The poly(ethylene furanate) bottle as described in claim 4, wherein the crystallinity determined by wide-angle X-ray diffraction using the following formula is 10% or more and 40% or less. Crystallinity (%) = Peak area of ​​crystalline material / (Peak area of ​​crystalline material + Peak area of ​​amorphous material) × 100.

6. A method for manufacturing high-viscosity polyethylene furanate, comprising a method for manufacturing polyethylene furanate according to any one of claims 1 to 3, including a polyethylene furanate raw material manufacturing step using a titanium catalyst to manufacture the raw material polyethylene furanate, and a solid-phase polymerization step of subjecting the raw material polyethylene furanate to solid-phase polymerization. The intrinsic viscosity of the raw material, polyethylene furanate dicarboxylate, as determined by the following method, is ≥0.65 dl / g and ≤0.85 dl / g, and the amount of decarboxylation terminal groups in the following formula is ≤20 eq / t. 0.25 g of polyethylene furanate was dissolved in 50 ml of a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (by weight) in a ratio of 50 / 50. The viscosity was measured using an Ubbelohde viscometer at 30 °C, with the Huggins constant set to 0.

32. 。 7. The method for manufacturing high-viscosity polyethylene furanate as described in claim 6, wherein, In the raw material polyethylene furanate, the ratio of the amount of decarboxylation terminal groups to the total amount of decarboxylation terminal groups and carboxylation terminal groups is less than 0.

5.

8. A polyester composition comprising polyethylene furanate as described in any one of claims 1 to 3 and a thermoplastic resin other than the polyethylene furanate.

9. The polyester composition of claim 8, wherein, The content of the poly(ethylene furanate) is 1-20% by weight, and the thermoplastic resin is polyethylene terephthalate.

10. A polyester composition comprising 50% by weight or more of the polyethylene furanate according to any one of claims 1 to 3, wherein, It also contains crosslinked thermoplastic resins and / or other thermoplastic polyester resins besides the aforementioned polyethylene furanate. The other thermoplastic polyester resins have terephthalic acid structural units and structural units selected from 1,4-butanediol structural units and polybutanediol structural units.

11. A method for manufacturing a polyester bottle, comprising a method for manufacturing a polyester bottle containing polyethylene furanate, wherein, It has an injection molding process for manufacturing a preform from raw polyester and a blow molding process for manufacturing a bottle from the preform. The raw material polyester contains polyethylene furanate as described in any one of claims 1 to 3.

12. A method for manufacturing a polyester bottle, comprising a method for manufacturing a polyester bottle containing polyethylene furanate, wherein, It has an injection molding process for manufacturing a preform from raw polyester and a blow molding process for manufacturing a bottle from the preform. The raw material polyester is the polyester composition according to claim 10.

13. A blow-molded bottle, which is a molded body of polyethylene furanate according to any one of claims 1 to 3 or a polyester composition according to any one of claims 8 to 10.

14. The blow-molded bottle of claim 13, used for filling a carbonated liquid.

15. The blow-molded bottle of claim 13, for filling hot beverages.

16. A beverage article comprising a beverage filled in a bottle as described in claim 4 or 5 or a blow-molded bottle as described in any one of claims 13 to 15.

Images