High heat-resistant polyester resin and method for preparing the same

Abstract

The present invention relates to a high heat-resistant polyester resin and a method for preparing the same. More specifically, according to one embodiment of the present invention, when a high heat-resistant polyester resin is immersed in water at 90°C for 7 days, the relationship between the glass transition temperature (Tg) and the amount of change in haze before and after immersion (ΔH) (ΔH / Tg) is satisfied to a value greater than 0.05 and less than 0.5. Therefore, high heat resistance that prevents deformation of shape even when used in a microwave oven or the like can be guaranteed without deterioration of properties such as transparency or mechanical properties.

Description

Detailed description of the invention

[0001] [Technical field] The present invention relates to a high heat-resistant polyester resin and a method for preparing a high heat-resistant polyester resin.

[0002] [Background technology] Due to their excellent mechanical properties and transparency, polyester resins are widely used as materials for textiles, films, sheets, packaging materials such as food containers, and automotive interior parts. In particular, food packaging materials are required to have durability and hydrolysis resistance to ensure food preservation, as well as high heat resistance to the extent that they do not change shape even when used in a microwave oven.

[0003] To improve the heat resistance and hydrolysis resistance of polyester resins, they are blended with other resins or various additives are used. However, there are limitations to how much heat resistance and hydrolysis resistance can be improved. Even when heat resistance or hydrolysis resistance can be improved, there is a problem of deterioration in properties such as transparency or mechanical properties. Therefore, research is underway to develop polyester resins that can ensure the durability and hydrolysis resistance required for food packaging materials, as well as high heat resistance sufficient to prevent shape deformation even when used in microwave ovens, without degrading properties such as transparency and mechanical properties.

[0004] As an example, Korean Published Patent Publication No. 2019-0064304 discloses a polyester resin having enhanced heat resistance achieved by copolymerizing a dicarboxylic acid compound containing isophthalic acid and a diol compound containing a cyclohexyl bisphenol compound. However, when a cyclohexyl bisphenol compound is used, the degree of crystallinity decreases, which deteriorates the viscosity properties and mechanical properties such as impact strength of the polyester resin.

[0005] [Prior art document] [Patent Document 1] Korean Published Patent Gazette No. 2019-0064304

[0006] [Disclosure of the Invention] [Technical issues] Therefore, the present invention aims to provide a high heat-resistant polyester resin that can ensure durability, hydrolysis resistance, and heat resistance without degrading properties such as transparency and mechanical properties, as well as a method for preparing the same.

[0007] [Solutions to the problem] The high heat-resistant polyester resin according to the present invention contains repeating units derived from a diol component and repeating units derived from an acid component, and satisfies the following relational formula 1. [Relationship 1] 0.05 < ΔH / Tg < 0.5

[0008] In relational equation 1, ΔH is the change in haze (haze after immersion - haze before immersion) of a 6 mm thick test specimen made from a high heat-resistant polyester resin when it is immersed in water at 90°C for 7 days, and Tg is the glass transition temperature of the high heat-resistant polyester resin.

[0009] A method for preparing a heat-resistant polyester resin according to another embodiment of the present invention comprises the steps of (a) preparing a composition containing a diol component and an acid component, (b) subjecting the composition to an esterification reaction at 200°C to 300°C, and (c) subjecting the product of the esterification reaction to a polycondensation reaction at a temperature of 220°C to 350°C and under a reduced pressure of 0.01 mmHg to 600 mmHg for 1 to 24 hours.

[0010] [Advantageous effects of the invention] According to one embodiment of the present invention, a high heat-resistant polyester resin satisfies the condition that the value of equation 1 (ΔH / Tg), which relates to the change in haze (ΔH) before and after immersion in water at 90°C for 7 days, and the glass transition temperature (Tg), is greater than 0.05 and less than 0.5. As a result, the high heat-resistant polyester resin can ensure durability, hydrolysis resistance, and heat resistance without degrading properties such as transparency and mechanical properties.

[0011] In particular, the high heat-resistant polyester resin contains a first diol containing isosorbide (ISB) or its derivative, a second diol containing cyclohexanedimethanol (CHDM) or its derivative, and a third diol different from the first and second diols, with the content of each of the first to third diols controlled within a specific range. As a result, it has high heat resistance to the extent that its shape does not change even when heat-treated at high temperatures, as well as excellent durability and hydrolysis resistance.

[0012] Therefore, when used as a food packaging material, high heat-resistant polyester resin can ensure the durability and hydrolysis resistance required for food packaging materials, as well as high heat resistance sufficient to prevent deformation even when used in a microwave oven.

[0013] [Best mode for carrying out the invention] The present invention will be described in detail below. The present invention is not limited to the disclosures given below, but can be modified in various forms as long as the essence of the invention is not altered.

[0014] Throughout this specification, unless otherwise specified, when a component is referred to as "containing" an element, it is understood that other elements may be included, rather than being excluded.

[0015] All numbers and expressions relating to the quantities of components and reaction conditions used herein should be understood to be modified by the term “approximately” unless otherwise indicated.

[0016] In this specification, when an element is said to be formed "on top of" or "below" another element, it means not only that one element is directly formed "on top of" or "below" another element, but also that one element is indirectly formed on top of or below another element(s) with other elements in between.

[0017] Throughout this specification, terms such as first, second, etc. are used to describe various components. However, the components should not be limited by terms such as first, second, etc. The terms first, second, etc. are used only for the purpose of distinguishing one component from another.

[0018] High heat resistance polyester resin The high heat resistance polyester resin according to the present invention contains repeating units derived from a diol component and repeating units derived from an acid component, and satisfies the following relational expression 1. [Relational expression 1] 0.05 < ΔH / Tg < 0.5

[0019] In relational expression 1, ΔH is the amount of change in haze before and after immersion of a test piece having a thickness of 6 mm prepared from the high heat resistance polyester resin when immersed in water at 90°C for 7 days (haze after immersion - haze before immersion), and Tg is the glass transition temperature of the high heat resistance polyester resin.

[0020] For example, ΔH / Tg according to relational expression 1 may be greater than 0.05 and less than 0.5, greater than 0.05 and less than 0.4, 0.06 - 0.35, 0.06 - 0.28, or 0.07 - 0.25. When ΔH / Tg according to relational expression 1 satisfies the above range, high heat resistance can be ensured without deterioration of hydrolysis resistance under high temperature and high humidity conditions.

[0021] Specifically, the high heat resistance polyester resin may have a glass transition temperature (Tg) of 110°C or higher. For example, the glass transition temperature of the high heat resistance polyester resin may be 112°C or higher, 115°C or higher, 116°C or higher, 120°C or higher, higher than 120°C, 122°C or higher, 124°C or higher, 126°C or higher, 130°C or higher, 132°C or higher, or 134°C or higher.

[0022] In addition, when a 6 mm thick test specimen prepared from a high heat-resistant polyester resin is immersed in water at 90°C for 7 days, the change in haze (ΔH, haze after immersion - haze before immersion) of the test specimen before and after immersion may be 30% or less. For example, the change in haze (ΔH) may be 30% or less, 29% or less, 27% or less, 25% or less, 24.5% or less, 24% or less, 20% or less, 18% or less, 12% or less, 10% or less, 8% or less, or 7% or less.

[0023] High heat-resistant polyester resin has a high glass transition temperature of 110°C or higher, and when immersed in water at 90°C for 7 days under high temperature and high humidity conditions, the change in haze before and after immersion is small, thus ensuring both high heat resistance and hydrolysis resistance simultaneously. As a result, the properties of high heat-resistant polyester resin, such as transparency, do not deteriorate even when exposed to high temperature and high humidity conditions, and the shape of high heat-resistant polyester resin does not change even when used in a microwave oven. Therefore, high heat-resistant polyester resin has excellent quality when used as a food packaging material.

[0024] In addition, the high heat-resistant polyester resin may have a haze (H1) of 1.5% or less, 1.45% or less, 1.25% or less, 1.1% or less, 0.9% or less, or 0.8% or less, measured before immersion, based on a test specimen prepared using it and having a thickness of 6 mm. In addition, the haze (H2) measured after the test specimen has been immersed in water at 90°C for 7 days may be 30% or less, 28% or less, 26% or less, 19% or less, 15% or less, 13% or less, 8% or less, or 7% or less. Test specimens prepared from the high heat-resistant polyester resin have a very low haze, and as described above, the haze does not increase significantly even under high temperature and high humidity conditions, exhibiting excellent hydrolysis resistance.

[0025] In addition, the high heat-resistant polyester resin may have an intrinsic viscosity (IV) of 0.55 dl / g or higher. For example, the intrinsic viscosity (IV) of the high heat-resistant polyester resin may be 0.58 dl / g or higher, 0.60 or higher, 0.62 dl / g or higher, 0.63 dl / g or higher, 0.7 dl / g or higher, or 0.75 dl / g or higher, and may be between 0.55 dl / g and 0.8 dl / g, between 0.56 dl / g and 0.75 dl / g, or between 0.58 dl / g and 0.72 dl / g.

[0026] When the intrinsic viscosity satisfies the above range, it is possible to ensure mechanical properties such as impact strength. Specifically, even if the composition and content of the resin are the same, the mechanical properties, especially the impact strength characteristics, may vary depending on the intrinsic viscosity. Therefore, in order to improve mechanical properties such as impact strength without degrading properties such as transparency and heat resistance, it is important to control the intrinsic viscosity along with the composition and content of the resin.

[0027] In addition, a test specimen prepared from a high heat-resistant polyester resin and having a thickness of 3.2 mm may have an impact strength of 700 J / m or more when measured according to ASTM D256. For example, a test specimen prepared from a high heat-resistant polyester resin and having a thickness of 3.2 mm may have an impact strength of 750 J / m or more, 770 J / m or more, 780 J / m or more, 820 J / m or more, or 850 J / m or more when measured according to ASTM D256.

[0028] Traditionally, research has been conducted to improve the heat resistance and impact strength of polyester resins, but there are limitations to improving heat resistance and hydrolysis resistance. Even when heat resistance or hydrolysis resistance can be improved, there is a problem of deterioration in other properties such as transparency and mechanical properties. Therefore, it has been difficult to ensure all properties such as heat resistance, hydrolysis resistance, transparency, and impact strength.

[0029] Impact strength changes sensitively with respect to the thickness of the test specimen, especially as the specimen becomes thicker. A high heat-resistant polyester resin according to one embodiment of the present invention has a glass transition temperature and a change in haze (ΔH) controlled to satisfy the above relational equation 1. As a result, the high heat-resistant polyester resin has superior impact strength compared to conventional resins, which typically have an impact strength of 310 J / m or less when measured according to ASTM D256 for a test specimen with a thickness of 3.2 mm prepared therefrom. In particular, the high heat-resistant polyester resin can ensure excellent impact resistance when the composition of the diol component is adjusted to a specific range, and properties such as intrinsic viscosity and glass transition temperature are also controlled.

[0030] According to one embodiment of the present invention, the high heat-resistant polyester resin includes repeating units derived from a diol component and repeating units derived from an acid component.

[0031] Specifically, the diol component may include (1) a first diol containing isosorbide (ISB) or a derivative thereof in an amount of 25 mol% to 45 mol%, (2) a second diol containing cyclohexanedimethanol (CHDM) or a derivative thereof in an amount of 45 mol% to 75 mol%, and (3) a third diol different from the first and second diols in an amount of 0 mol% to 25 mol%.

[0032] The diol component may include a first diol containing isosorbide (ISB) or a derivative thereof, and the first diol may be present in an amount of 25 mol% to 45 mol% based on the total number of moles of the diol component. For example, the high heat-resistant polyester resin may be a resin in which the diol component and the acid component are copolymerized, and the content of the first diol may be 25 mol% to 42 mol%, 26 mol% to 40 mol%, 25 mol% to 39 mol%, 28 mol% to 41 mol%, 28 mol% to 39 mol%, 30 mol% to 39 mol%, or 28 mol% to 35 mol%, based on the total diol-derived residues in the high heat-resistant polyester resin.

[0033] When the content of the first diol meets the above range, it is possible to ensure excellent heat resistance without degrading properties such as transparency or mechanical properties. Specifically, if the content of the first diol is less than 25 mol%, it is difficult to ensure sufficient heat resistance for use in materials such as food packaging materials, and especially high heat resistance that prevents shape change even when used in a microwave oven. If the content of the first diol exceeds 45 mol%, properties such as transparency and mechanical properties may deteriorate.

[0034] In addition, the diol component may include a second diol containing cyclohexanedimethanol (CHDM) or a derivative thereof, and the second diol may be present in an amount of 45 mol% to 75 mol% based on the total number of moles of the diol component. For example, the content of the second diol may be 45 mol% to 73 mol%, 46 mol% to 73 mol%, 46 mol% to 72 mol%, 46 mol% to 70 mol%, or 46 mol% to 68 mol%, based on the total diol-derived residues in the high heat-resistant polyester resin.

[0035] When the content of the second diol meets the above range, it is possible to improve mechanical properties such as hydrolysis resistance and impact strength without degrading heat resistance. Specifically, if the content of the second diol is less than 45 mol%, mechanical properties such as impact strength may deteriorate, which will worsen the durability or lifespan characteristics of products prepared from high heat-resistant polyester resin. If the content of the second diol exceeds 75 mol%, crystalline properties may increase due to reactivity with the first diol, which will significantly worsen transparency and hydrolysis resistance.

[0036] In addition, the molar ratio of the first diol to the second diol may be 1:1 to 3.2. For example, the molar ratio of the first diol to the second diol may be 1:1.2 to 3, 1:1.25 to 2.8, 1:1 to 2.6, 1:1.3 to 2.6, 1:1.5 to 3, 1:1.7 to 2.8, 1:1.8 to 3.2, 1:2 to 2.8, or 1:2.1 to 2.8.

[0037] Isosorbide has been used in the preparation of polyester resins because it can increase heat resistance by raising the glass transition temperature, but it may degrade transparency, color properties, and mechanical properties such as impact strength. Therefore, research is ongoing to solve these problems.

[0038] A highly heat-resistant polyester resin according to one embodiment of the present invention contains 25 mol% to 45 mol% isosorbide, and the molar ratio of the first diol to the second diol satisfies the above range. As a result, it is possible to ensure high heat resistance without degrading transparency, color characteristics, and mechanical properties such as impact strength.

[0039] In addition, the diol component may include a third diol different from the first and second diols, and the third diol may be included in an amount of 0 mol% to 25 mol% based on the total number of moles of the diol component. For example, the content of the third diol may be 0 mol% to 20 mol%, 1 mol% to 25 mol%, 3 mol% to 20 mol%, 4.5 mol% to 15 mol%, 5 mol% to 13 mol%, or 5 mol% to 12 mol%, based on the total diol-derived residues in the high heat-resistant polyester resin.

[0040] The third diol may include at least one selected from the group consisting of bis-2-hydroxyethyl terephthalate, regenerated bis-2-hydroxyethyl terephthalate, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 2-methylene-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-isopropyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,3-butanediol, 3-methyl-1,5-pentanediol, 3-methyl-2,4-pentanediol, 1,6-hexanediol, and derivatives thereof.

[0041] According to one embodiment of the present invention, it is important to adjust the content of the first to third diols in the high heat-resistant polyester resin.

[0042] Specifically, in order to achieve the desired physical properties in the present invention, and more specifically, to improve heat resistance and hydrolysis resistance without degrading properties such as transparency and mechanical properties, it is extremely important to adjust the content of the first to third diols in the high heat-resistant polyester resin. Therefore, according to one embodiment of the present invention, when the content of the first to third diols satisfies the respective ranges described above, it is possible to ensure high heat resistance such that the shape does not change even when heat-treated at high temperatures. Thus, when the high heat-resistant polyester resin is used as a food packaging material, it can ensure the durability and hydrolysis resistance required for food packaging materials, as well as high heat resistance such that the shape does not change even when used in a microwave oven.

[0043] In addition, the acid component may be a dicarboxylic acid or a derivative of a dicarboxylic acid.

[0044] For example, the acid component may include at least one selected from the group consisting of terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalate, phthalic acid, dimethyl phthalate, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid dimethyl, diphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid dimethyl, 1,3-cyclohexanedicarboxylic acid dimethyl, sebacic acid, succinic acid, isodecylsuccinic acid, maleic acid, maleic anhydride, fumaric acid, adipic acid, glutaric acid, and azelaic acid.

[0045] Specifically, the acid component may be terephthalic acid or a derivative of terephthalic acid, and more specifically, the acid component may be terephthalic acid or dimethyl terephthalate, but is not limited to these. For example, the high heat-resistant polyester resin may contain residues derived from terephthalic acid or dimethyl terephthalate in amounts of 100 mol%, 98 mol% or less, 95 mol% or less, or 90 mol% or less based on the total acid-derived residues in the high heat-resistant polyester resin.

[0046] According to another embodiment of the present invention, the acid component may further contain a dicarboxylic acid or a dicarboxylic acid derivative different from terephthalic acid or a derivative of terephthalic acid, while including terephthalic acid or a derivative of terephthalic acid. For example, the acid component may include terephthalic acid and isophthalic acid, or dimethyl terephthalate and isophthalic acid, and the content of terephthalic acid or dimethyl terephthalate may be 90 mol% to 99 mol%, 92 mol% to 98 mol%, 93 mol% to 97 mol%, or 94 mol% to 96 mol%, based on the total acid-derived residues in the high heat-resistant polyester resin, and the content of isophthalic acid may be 1 mol% to 10 mol%, 2 mol% to 8 mol%, 3 mol% to 7 mol%, or 4 mol% to 6 mol%.

[0047] According to one embodiment of the present invention, the high heat-resistant polyester resin may further contain at least one additive selected from the group consisting of colorants, crystallizers, oxidation stabilizers, and branching agents.

[0048] The colorants are additives used to enhance the color properties of high-heat-resistant polyester resins. Commonly used colorants such as cobalt acetate and cobalt propionate may be used as colorants, as long as the effects of the present invention are not diminished.

[0049] Specifically, the colorants may be cobalt acetate, cobalt propionate, anthraquinone compounds, perinone compounds, azo compounds, and methine compounds. Commercially available toners such as Clariant's Polysynthren Blue RLS or Clariant's Solvaperm Red BB may be used.

[0050] In addition, the high heat-resistant polyester resin may contain a coloring agent in an amount of 0.1 ppm to 40 ppm based on the total weight of the high heat-resistant polyester resin. For example, the coloring agent content may be 1 ppm to 40 ppm, 3 ppm to 35 ppm, 5 ppm to 30 ppm, or 10 ppm to 30 ppm based on the total weight of the high heat-resistant polyester resin. When the coloring agent content satisfies the above range, the color characteristics of the high heat-resistant polyester resin can be sufficiently enhanced without degrading the mechanical properties of the high heat-resistant polyester resin.

[0051] The crystallizing agent may include at least one selected from the group consisting of crystal nucleating agents, UV absorbers, polyolefin resins, polyamide resins, and polyalkylene resins.

[0052] In addition, the high heat-resistant polyester resin may contain a crystallizing agent in an amount of 0.1 ppm to 10 ppm based on the total weight of the high heat-resistant polyester resin. For example, the crystallizing agent content may be 0.2 ppm to 8 ppm, 0.5 ppm to 6 ppm, 1 ppm to 10 ppm, 2 ppm to 8 ppm, 3 ppm to 6 ppm, or 4 ppm to 6 ppm based on the total weight of the high heat-resistant polyester resin. When the crystallizing agent content meets the above ranges, the heat resistance and impact strength can be improved.

[0053] The oxidation stabilizer may include at least one selected from the group consisting of hindered phenol-based oxidation stabilizers, phosphite-based oxidation stabilizers, and thioether-based oxidation stabilizers.

[0054] In addition, the high heat-resistant polyester resin may contain an oxidation stabilizer in an amount of 50 ppm to 2,500 ppm based on the total weight of the high heat-resistant polyester resin. For example, the oxidation stabilizer content may be 50 ppm to 2,300 ppm, 60 ppm to 2,200 ppm, 80 ppm to 2,100 ppm, 100 ppm to 2,000 ppm, or 100 ppm to 1,500 ppm based on the total weight of the high heat-resistant polyester resin. When the oxidation stabilizer content meets the above range, it is possible to effectively prevent a decrease in intrinsic viscosity that may occur in subsequent processes, and also prevent a decrease in physical properties such as impact strength.

[0055] The branching agent may include at least one selected from the group consisting of trimellitic anhydride, trimethylolpropane, and trimellitic anhydride.

[0056] In addition, the high heat-resistant polyester resin may contain a branching agent in an amount of 100 ppm to 2,500 ppm based on the total weight of the high heat-resistant polyester resin. For example, the branching agent may be used in amounts of 150 ppm to 2,000 ppm, 200 ppm to 1,800 ppm, 300 ppm to 1,500 ppm, or 300 ppm to 1,000 ppm based on the total weight of the high heat-resistant polyester resin. When the branching agent content satisfies the above range, the intrinsic viscosity can be more effectively controlled within a specific range, and as a result, physical properties such as impact strength can also be improved.

[0057] Method for preparing high heat-resistant polyester resin A method for preparing a heat-resistant polyester resin according to another embodiment of the present invention comprises the steps of (a) preparing a composition containing a diol component and an acid component, (b) subjecting the composition to an esterification reaction at 200°C to 300°C, and (c) subjecting the product of the esterification reaction to a polycondensation reaction at a temperature of 220°C to 350°C and under a reduced pressure of 0.01 mmHg to 600 mmHg for 1 to 24 hours.

[0058] A high heat-resistant polyester resin prepared according to a method for preparing a high heat-resistant polyester resin has substantially the same composition and properties as the high heat-resistant polyester resin described above.

[0059] In addition, the composition and process conditions may be adjusted so that the high heat-resistant polyester resin finally prepared according to the method for preparing high heat-resistant polyester resin satisfies the aforementioned properties such as transparency, heat resistance, hydrolysis resistance, and mechanical properties such as impact strength.

[0060] First, a composition containing a diol component and an acid component is prepared (step (a)).

[0061] Details regarding the diol and acid components are as described above.

[0062] The molar ratio (G / A) of the diol component to the acid component added in step (a) may be between 1.10 and 3.00. For example, the molar ratio (G / A) of the diol component to the acid component added in step (a) may be between 1.15 and 2.20, 1.20 and 2.00, 1.20 and 1.50, and 1.20 and 1.25. When the molar ratio (G / A) of the diol component to the acid component satisfies the above range, productivity can be increased without deterioration of transparency, and mechanical properties such as heat resistance, hydrolysis resistance, and impact strength can be ensured.

[0063] In addition, at least one additive selected from the group consisting of colorants, crystallizers, oxidative stabilizers, and branching agents may be further added to the composition. Details regarding the additives are as described above.

[0064] The composition is subjected to an esterification reaction at 200°C to 300°C (step (b)).

[0065] The esterification reaction takes place at a pressure of 0.1 kg / cm³ above normal pressure. 2 ~3.0 kg / cm 2 It may also be carried out at high pressure and a temperature of 200°C to 300°C for 1.5 to 10 hours.

[0066] The pressure is 0.1 kg / cm 2 ~3.0 kg / cm 2 、0.2 kg / cm 2 ~2.5 kg / cm 2 、0.3 kg / cm 2 ~2.2 kg / cm 2 、0.5 kg / cm 2 ~2.0 kg / cm 2 、or 0.5 kg / cm 2 ~1.0 kg / cm 2 only may be higher than the normal pressure.

[0067] In addition, the esterification reaction may be carried out at a temperature of 245°C to 280°C, 250°C to 275°C, or 255°C to 270°C for 1.5 hours to 8 hours, 1.5 hours to 6 hours, or 2 hours to 4 hours.

[0068] More specifically, the esterification reaction may be carried out in the steps of: (b-1) injecting nitrogen into the reactor containing the composition and setting the pressure to be only higher than the normal pressure by 0.1 kg / cm 2 ~3.0 kg / cm 2 ; (b-2) raising the temperature of the reactor from room temperature to 210°C to 230°C over 60 minutes to 120 minutes and then maintaining the state for 1 hour to 3 hours; and (b-3) raising the temperature to 245°C to 275°C over 1 hour to 3 hours and then subjecting the composition to the esterification reaction.

[0069] In step (b-2), the temperature of the reactor may be raised from room temperature to 210°C to 230°C or 215°C to 225°C over 70 minutes to 110 minutes or 80 minutes to 100 minutes and then maintained for 1 hour to 3 hours or 1 hour to 2 hours.

[0070] [[ID=!]]

[0071] The product of the esterification reaction is subjected to polycondensation reaction at a temperature of 220°C to 350°C and under reduced pressure of 0.01 mmHg to 600 mmHg for 1 to 24 hours.

[0072] For example, the polycondensation reaction may be carried out at temperatures of 230°C to 320°C, 250°C to 295°C, 260°C to 290°C, or 265°C to 280°C, and at pressures of 0.01 mmHg to 400 mmHg, 0.05 mmHg to 200 mmHg, 0.1 mmHg to 50 mmHg, 0.2 mmHg to 10 mmHg, 0.2 mmHg to 3 mmHg, 0.3 mmHg to 1.5 mmHg, or 0.5 mmHg to 1 mmHg, for 1 to 20 hours, 2 to 16 hours, or 3 to 10 hours.

[0073] Specifically, the polycondensation reaction may be carried out in the following steps: (c-1) reducing the pressure of the esterification product to 4.0 mmHg to 6.0 mmHg over 10 to 60 minutes, and (c-2) raising the temperature to 220°C to 350°C over 0.5 to 2 hours, and then carrying out the polycondensation reaction while maintaining a pressure of 0.01 mmHg to 600 mmHg.

[0074] Step (c-1) may also be a step of reducing the pressure of the esterification reaction product from 4.0 mmHg to 6.0 mmHg or 4.5 mmHg to 5.5 mmHg over a period of 20 to 50 minutes or 25 to 40 minutes.

[0075] In addition, in step (c-2), the temperature may be raised to 250°C to 320°C, 255°C to 285°C, 260°C to 285°C, or 265°C to 280°C over a period of 0.5 to 2 hours or 0.8 to 1.5 hours.

[0076] At the start of the polycondensation reaction, the stirring speed may be set high. As the polycondensation reaction progresses, if the stirring force weakens due to an increase in the viscosity of the reactants, or if the temperature of the reactants rises above the set temperature, the stirring speed may be adjusted accordingly.

[0077] The polycondensation reaction may be carried out until the intrinsic viscosity (IV) of the polycondensation product is 0.55 dl / g or higher, 0.58 dl / g or higher, 0.60 or higher, 0.62 dl / g or higher, 0.63 dl / g or higher, 0.7 dl / g or higher, 0.75 dl / g or higher, or 0.55 dl / g to 0.8 dl / g, 0.56 dl / g to 0.75 dl / g, or 0.58 dl / g to 0.72 dl / g.

[0078] In addition, catalysts and / or stabilizers may be further added in the esterification and polycondensation reactions.

[0079] For example, catalysts for esterification reactions may include sodium and magnesium methylates; acetates, borates, fatty acid salts, and carbonates of Zn, Cd, Mn, Co, Ca, and Ba; metallic Mg; and oxides of Pb, Zn, Sb, and Ge.

[0080] In addition, catalysts for the polycondensation reaction may include, for example, titanium-based catalysts such as tetraethyl titanate, tripropylacetyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylene glycol titanate, titanium lactate, triethanolamine titanate, acetylacetonate titanate, ethylacetoacetate titanate, isostearyl titanate, titanium dioxide, titanium dioxide / silicon dioxide copolymer, and titanium dioxide / zirconium dioxide copolymer; germanium-based catalysts such as germanium dioxide and copolymers using germanium dioxide; or tin-based catalysts such as monobutyltin oxide, dibutyltin oxide, and monobutylhydroxytin oxide.

[0081] In certain embodiments, a catalyst may be further added in step (a), and the catalyst may contain germanium or tin, or it may be a zinc-based catalyst.

[0082] In addition, the stabilizer may be phosphorus-based compounds such as phosphoric acid or trimethyl phosphate, and triethyl phosphate may also be used, but is not limited to these.

[0083] The stabilizer may be used in an amount of 1 ppm to 2,500 ppm based on the total weight of the high heat-resistant polyester resin. For example, the stabilizer may be used in an amount of 1 ppm to 2,300 ppm, 5 ppm to 2,000 ppm, 10 ppm to 1,500 ppm, 20 ppm to 400 ppm, 30 ppm to 350 ppm, or 50 ppm to 300 ppm based on the total weight of the high heat-resistant polyester resin.

[0084] In certain embodiments, a stabilizer may be further added in step (a), and the stabilizer may include at least one compound selected from the group consisting of phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and triethyl phosphonoacetate.

[0085] molded product A molded article according to another embodiment of the present invention comprises a high heat-resistant polyester resin.

[0086] For example, the molded articles may be, but are not limited to, containers for various foods and beverages, packaging materials, medical devices, or heat-resistant sheets.

[0087] In addition, the molded articles may be obtained by injection molding of a high-heat-resistant polyester resin. For example, the molded articles may be prepared by injection molding of a high-heat-resistant polyester resin at 260°C to 350°C, 265°C to 320°C, or 270°C to 300°C. High-heat-resistant polyester resin has excellent heat resistance, and therefore, even when injection molding is performed at the high temperatures mentioned above, the shape does not distort or deform during molding, and the processability is excellent. Molded articles prepared from high-heat-resistant polyester resin do not deform even when heated, such as when used in a microwave oven, and therefore, the quality of molded articles prepared from high-heat-resistant polyester resin is excellent.

[0088] [Modes of the Invention] The present invention will be described in more detail below with reference to the following examples. However, these examples are provided for illustrative purposes only, and the scope of the invention is not limited thereto.

[0089] Preparation of high heat-resistant polyester resin Example 1 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled with water was packed with terephthalic acid (TPA, 2,209 g), ethylene glycol (EG, 66 g), cyclohexanedimethanol (CHDM, 1,246 g), and isosorbide (ISB, 1,010 g). The G / A ratio (total diols / total acids; molar ratio of diol components to acid components) was 1.25.

[0090] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.2 g of cobalt acetate as a colorant, 0.022 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), 0.004 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant), and 0.36 g of hindered phenol-based oxidation stabilizer (product name: Irganox 1076, manufacturer: BASF) were added, and the mixture was then stirred to prepare the composition.

[0091] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 1.0 kgf / cm² above atmospheric pressure. 2The absolute pressure was increased by 1,495.6 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 268°C over 2 hours. Subsequently, the esterification reaction was carried out at 268°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0092] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification reaction product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 278°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.68 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to an average weight of approximately 12 mg to 14 mg to prepare a high heat-resistant polyester resin.

[0093] Example 2 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled with water was packed with terephthalic acid (TPA, 2,297 g), cyclohexanedimethanol (CHDM, 1,435 g), and isosorbide (ISB, 970 g). The G / A (total diol / total acid; molar ratio of diol component to acid component) was 1.2.

[0094] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.030 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), and 0.007 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant) were added, and the mixture was then stirred to prepare the composition.

[0095] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 1.0 kgf / cm² above atmospheric pressure. 2 The absolute pressure was increased by 1,495.6 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 264°C over 2 hours. Subsequently, the esterification reaction was carried out at 264°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0096] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 268°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.71 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high-heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0097] Example 3 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled by water was packed with terephthalic acid (TPA, 2,201 g), ethylene glycol (EG, 140 g), cyclohexanedimethanol (CHDM, 1,050 g), and isosorbide (ISB, 968 g). The G / A ratio (total diols / total acids; molar ratio of diol components to acid components) was 1.22.

[0098] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.3 g of cobalt acetate as a colorant, 0.018 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), 0.004 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant), and 3.5 g of hindered phenol-based oxidation stabilizer (product name: Irganox 1076, manufacturer: BASF) were added, and the mixture was then stirred to prepare the composition.

[0099] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 0.5 kgf / cm² above atmospheric pressure. 2 The absolute pressure was increased by 1,127.8 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 258°C over 2 hours. Subsequently, the esterification reaction was carried out at 258°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0100] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 273°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.65 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0101] Example 4 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled with water was packed with terephthalic acid (TPA, 2,608 g), isophthalic acid (IPA, 137 g), ethylene glycol (EG, 308 g), cyclohexanedimethanol (CHDM, 1,191 g), and isosorbide (ISB, 917 g). The G / A ratio (total diols / total acids; molar ratio of diol components to acid components) was 1.24.

[0102] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.025 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), 0.006 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant), and 1.26 g of trimellitic anhydride as a branching agent were added, and the mixture was then stirred to prepare the composition.

[0103] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 0.7 kgf / cm² above atmospheric pressure. 2The absolute pressure was increased by 1,274.9 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 263°C over 2 hours. Subsequently, the esterification reaction was carried out at 263°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0104] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 268°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.66 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high-heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0105] Example 5 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled with water was packed with terephthalic acid (TPA, 1,936 g), ethylene glycol (EG, 101 g), cyclohexanedimethanol (CHDM, 840 g), and isosorbide (ISB, 988 g). The G / A (total diol / total acid; molar ratio of diol component to acid component) was 1.22.

[0106] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.4 g of cobalt acetate as a colorant, 0.016 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), 0.003 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant), 6.2 g of hindered phenol-based oxidation stabilizer (product name: Irganox 1076, manufacturer: BASF), and 3.1 g of trimellitic anhydride as a branching agent were added, and then the mixture was stirred to prepare the composition.

[0107] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 0.8 kgf / cm² above atmospheric pressure. 2 The absolute pressure was increased by 1,348.5 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 268°C over 2 hours. Subsequently, the esterification reaction was carried out at 268°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0108] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 278°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.59 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high-heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0109] Comparative Example 1 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled with water was packed with terephthalic acid (TPA, 2,409 g), ethylene glycol (EG, 288 g), cyclohexanedimethanol (CHDM, 1,567 g), and isosorbide (ISB, 381 g). The G / A ratio (total diols / total acids; molar ratio of diol components to acid components) was 1.25.

[0110] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.3 g of cobalt acetate as a colorant, 0.023 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), 0.004 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant), and 0.38 g of hindered phenol-based oxidation stabilizer (product name: Irganox 1076, manufacturer: BASF) were added, and the mixture was then stirred to prepare the composition.

[0111] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 1.0 kgf / cm² above atmospheric pressure. 2 The absolute pressure was increased by 1,495.6 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 260°C over 2 hours. Subsequently, the esterification reaction was carried out at 260°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0112] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 275°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.72 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high-heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0113] Comparative Example 2 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled with water was packed with terephthalic acid (TPA, 2,470 g), ethylene glycol (EG, 157 g), cyclohexanedimethanol (CHDM, 1,393 g), and isosorbide (ISB, 782 g). The G / A ratio (total diols / total acids; molar ratio of diol components to acid components) was 1.18.

[0114] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.2 g of cobalt acetate as a colorant, 0.031 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), and 0.007 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant) were added, and the mixture was then stirred to prepare the composition.

[0115] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 1.0 kgf / cm² above atmospheric pressure. 2 The absolute pressure was increased by 1,495.6 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 270°C over 2 hours. Subsequently, the esterification reaction was carried out at 270°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0116] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification reaction product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 280°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.66 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0117] Comparative Example 3 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled by water was packed with terephthalic acid (TPA, 2,621 g), ethylene glycol (EG, 176 g), cyclohexanedimethanol (CHDM, 1,842 g), and isosorbide (ISB, 369 g). The G / A ratio (total diols / total acids; molar ratio of diol components to acid components) was 1.15.

[0118] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.021 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), and 0.003 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant) were added, and the mixture was then stirred to prepare the composition.

[0119] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 0.5 kgf / cm² above atmospheric pressure. 2The absolute pressure was increased by 1,127.8 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 264°C over 2 hours. Subsequently, the esterification reaction was carried out at 264°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0120] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 278°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.76 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high-heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0121] Comparative Example 4 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled by water was packed with terephthalic acid (TPA, 2,683 g), ethylene glycol (EG, 230 g), cyclohexanedimethanol (CHDM, 931 g), and isosorbide (ISB, 1,298 g). The G / A ratio (total diols / total acids; molar ratio of diol components to acid components) was 1.18.

[0122] Subsequently, 2.5 g of GeO2 as a catalyst, 5.0 g of phosphoric acid as a stabilizer, 0.024 g of blue toner (product name: Polysynthren Blue RLS, manufacturer: Clariant), 0.004 g of red toner (product name: Solvaperm Red BB, manufacturer: Clariant), and 6 g of hindered phenol-based oxidation stabilizer (product name: Irganox 1076, manufacturer: BASF) were added, and the mixture was then stirred to prepare the composition.

[0123] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 0.8 kgf / cm² above atmospheric pressure. 2 The absolute pressure was increased by 1,348.5 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 268°C over 2 hours. Subsequently, the esterification reaction was carried out at 268°C for 3 hours, while visually monitoring the composition in the reactor, until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and then the esterification product in the reactor was transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0124] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification reaction product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 268°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.54 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0125] Comparative Example 5 (a) Preparation of the composition A 10-liter reactor equipped with a condenser and column that could be cooled with water was packed with terephthalic acid (TPA, 2,000 g), cyclohexanedimethanol (CHDM, 1,194 g), and isosorbide (ISB, 726 g). The G / A (total diol / total acid; molar ratio of diol component to acid component) was 1.10.

[0126] Subsequently, 1.39 g of dibutyltin oxide and 1.65 g of a hindered phenol-based oxidation stabilizer (product name: Irganox, manufacturer: BASF) were added as catalysts, and the mixture was then stirred to prepare the composition.

[0127] (b) Esterification reaction Next, nitrogen is injected into the reactor containing the composition, raising the pressure inside the reactor to 6.6 kgf / cm² above atmospheric pressure. 2The absolute pressure was increased by 4,119.4 mmHg. The reactor temperature was then raised from room temperature to 220°C over 90 minutes, maintained at 220°C for 2 hours, and then raised again to 275°C over 2 hours. Subsequently, the esterification reaction was carried out at 275°C for 3 hours while visually monitoring the composition in the reactor until the composition became clear. Once the esterification reaction was complete, the nitrogen in the pressurized reactor was purged to the outside, reducing the pressure in the reactor to atmospheric pressure, and the esterification product in the reactor was then transferred to a 7-liter reactor capable of reacting under reduced pressure.

[0128] (c) Polycondensation reaction Subsequently, the pressure in the reactor containing the esterification reaction product was reduced from atmospheric pressure to 5.0 Torr (absolute pressure: 5 mmHg) over 30 minutes. Simultaneously, the reactor temperature was raised to 285°C over 1 hour, and the polycondensation reaction was carried out while maintaining the reactor pressure at 1.0 Torr (absolute pressure: 1.0 mmHg) or less. At the start of the polycondensation reaction, the stirring speed was set high. As the polycondensation reaction progressed, if the stirring force weakened due to the increase in the viscosity of the reactants, or if the temperature of the reactants rose above the set temperature, the stirring speed was adjusted accordingly. The polycondensation reaction was carried out until the intrinsic viscosity (IV) of the mixture (molten material) in the reactor reached 0.46 dl / g. Next, the mixture was discharged from the reactor to form strands, which were solidified using a cooling liquid, and then granulated to prepare a high heat-resistant polyester resin with an average weight of approximately 12 mg to 14 mg.

[0129] Test example Test Example 1: Composition of high heat-resistant polyester resin The high heat-resistant polyester resins of Examples 1-5 and Comparative Examples 1-5 were each dissolved in CDCl3 solvent at a concentration of 3 mg / ml. The composition (mol%) of the high heat-resistant polyester resins was then measured by 1H-NMR spectroscopy obtained using a nuclear magnetic resonance spectrometer (JEOL, 600 MHz FT-NMR) at 25°C.

[0130] Test Example 2: Glass Transition Temperature The high heat-resistant polyester resins of Examples 1-5 and Comparative Examples 1-5 were measured with respect to the glass transition temperature (Tg) as the first endothermic temperature in the second scan obtained using a differential scanning calorimeter (DSC).

[0131] Specifically, a first scan was obtained by increasing the temperature from 30°C to 280°C at a rate of 10°C / min and maintaining the temperature at 280°C for 2 minutes. A second scan was then obtained by decreasing the temperature from 280°C to 30°C at a rate of -300°C / min and maintaining the temperature for 15 minutes, and then increasing the temperature again from 30°C to 280°C at a rate of 10°C / min.

[0132] Test Example 3: Hayes High heat-resistant polyester resins for Examples 1-5 and Comparative Examples 1-5 were injection molded to prepare test specimens with a thickness of 6 mm (length and width of 37 mm). The test specimens were immersed in a sealed container filled with water at 90°C for 7 days. In this case, the sealed container was placed in a hot air dryer to maintain a temperature of 85°C. The haze (%) before and after immersion was measured using an NDK Hazemeter NDH7000. In Comparative Example 5, it was not possible to prepare an injection-molded test specimen, so the haze could not be measured.

[0133] In addition, the change in haze before and after immersion (ΔH, haze after immersion - haze before immersion) was calculated, and the value of relation 1 (ΔH / Tg) was calculated using the glass transition temperature (Tg) measured in Test Example 2.

[0134] Test Example 4: Impact Strength The high heat-resistant polyester resins of Examples 1-5 and Comparative Examples 1-5 were each measured in terms of impact strength (J / m) according to ASTM D256.

[0135] Specifically, each high-heat-resistant polyester resin was injection-molded at 270°C to prepare test specimens (width: 63.3 mm, length: 12.5 mm, thickness: 3.2 mm), and a 2.3 mm notch was formed in the center of the test specimen using a notch meter in accordance with ISO 2818.

[0136] Subsequently, one end of the test specimen was fixed, and the other end was struck with a hammer in the direction of the notch. The impact strength was then measured using an impact strength measuring device (product name: NO.258PC-S impact tester, manufacturer: Yasuda Seiki Seisakusho Co., Ltd., hammer capacity: 5.5J). This measurement was performed 10 times, and the average value was calculated.

[0137] Test Example 5: Intrinsic Viscosity The high heat-resistant polyester resins of Examples 1-5 and Comparative Examples 1-5 were each dissolved in ortho-chlorophenol (OCP) at a concentration of 0.12% at 150°C, and their intrinsic viscosity (IV, dl / g) was measured using an Ubbelohde viscometer in a constant temperature apparatus at 35°C.

[0138] Test Example 6: Processability at High Temperatures The high heat-resistant polyester resins of Examples 1-5 and Comparative Examples 1-5 were dried, and then injection-molded at 270°C to 290°C to prepare sealed containers with a capacity of 500 ml. The sealed containers thus prepared were placed in a microwave oven, heated at 1,000W for 2 minutes, cooled to room temperature, and then heated again for 2 minutes. The shape of the sealed containers was examined to see if they deformed or not. The evaluation was performed according to the following criteria. In Comparative Example 5, it was not possible to prepare an injection-molded test piece, so processability could not be evaluated. ○ (white circle): Almost no deformation. △ (White triangle): Deformation occurred during the second heating process. ×: Deformation occurred during the first heating. [Table 1] [Table 2]

[0139] As can be seen from Tables 1 and 2 above, the high heat-resistant polyester resins of Examples 1 to 5 had high glass transition temperatures and excellent heat resistance. Therefore, the high heat-resistant polyester resins of Examples 1 to 5 were excellent in all properties, including the amount of change in haze, impact strength, and intrinsic viscosity when immersed in water at 90°C for 7 days.

[0140] Specifically, in the high heat-resistant polyester resins of Examples 1 to 5, the content and molar ratio of diol components, particularly isosorbide and cyclohexanedimethanol, were controlled within a specific range. As a result, the glass transition temperature was excellent, exceeding 110°C, while the haze value was improved even under high temperature and high humidity conditions, and both impact strength and intrinsic viscosity were excellent. In addition, the sealed containers prepared using each of the high heat-resistant polyester resins of Examples 1 to 5, which possessed excellent processability, showed no deformation such as distortion of shape even after being heated once and twice in a microwave oven at a power of 1,000W.

[0141] In contrast, the resins of Comparative Examples 1 to 5 had a glass transition temperature of less than 110°C or very high haze values ​​under high temperature and high humidity conditions, and the impact strength of the resins of Comparative Examples 1 to 5 was also lower than that of Examples 1 to 5. In particular, in Comparative Example 5, the mechanical properties necessary for preparing test specimens for injection molding were not ensured, and therefore, test specimens could not be prepared.

Claims

1. It includes repeating units derived from the diol component and repeating units derived from the acid component, and the following relational equation 1: [Relationship 1] 0.05<ΔH / Tg<0.5 A highly heat-resistant polyester resin that satisfies the following conditions: In relational equation 1, ΔH is the change in haze (haze after immersion - haze before immersion) of a 6 mm thick test specimen prepared from the high heat-resistant polyester resin when it is immersed in water at 90°C for 7 days, and Tg is the glass transition temperature of the high heat-resistant polyester resin. High heat-resistant polyester resin.

2. The high heat-resistant polyester resin according to claim 1, wherein the Tg is 110°C or higher.

3. The high heat-resistant polyester resin according to claim 1, wherein the ΔH is 30% or less.

4. The high heat-resistant polyester resin according to claim 1, having an intrinsic viscosity (IV) of 0.55 dl / g or more.

5. The high heat-resistant polyester resin according to claim 1, wherein a test specimen having a thickness of 3.2 mm prepared from the high heat-resistant polyester resin has an impact strength of 700 J / m or more when measured according to ASTM D256.

6. The aforementioned diol component is (1) A first diol containing 25 mol% to 45 mol% isosorbide (ISB) or a derivative thereof, (2) A second diol comprising 45 mol% to 75 mol% of cyclohexanedimethanol (CHDM) or a derivative thereof, (3) A third diol different from the first diol and the second diol, in an amount of 0 mol% to 25 mol% A high heat-resistant polyester resin according to claim 1, comprising the above.

7. The high heat-resistant polyester resin according to claim 6, wherein the molar ratio of the first diol to the second diol is 1:1 to 3.

2.

8. The high heat-resistant polyester resin according to claim 6, wherein the third diol comprises at least one selected from the group consisting of bis-2-hydroxyethyl terephthalate, regenerated bis-2-hydroxyethyl terephthalate, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 2-methylene-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-isopropyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,3-butanediol, 3-methyl-1,5-pentanediol, 3-methyl-2,4-pentanediol, 1,6-hexanediol, and derivatives thereof.

9. The high heat-resistant polyester resin according to claim 1, wherein the acid component comprises at least one selected from the group consisting of terephthalic acid, dimethyl terephthalate, isophthalic acid, dimethyl isophthalate, phthalic acid, dimethyl phthalate, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid dimethyl, diphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid dimethyl, 1,3-cyclohexanedicarboxylic acid dimethyl, sebacic acid, succinic acid, isodecylsuccinic acid, maleic acid, maleic anhydride, fumaric acid, adipic acid, glutaric acid, and azelaic acid.

10. The high heat-resistant polyester resin according to claim 1, further comprising at least one additive selected from the group consisting of colorants, crystallizers, oxidation stabilizers, and branching agents.

11. The high heat-resistant polyester resin according to claim 10, wherein the crystallizing agent comprises at least one selected from the group consisting of a crystal nucleating agent, a UV absorber, a polyolefin resin, a polyamide resin, and a polyalkylene resin, and the crystallizing agent is used in an amount of 0.1 ppm to 10 ppm based on the total weight of the high heat-resistant polyester resin.

12. The high heat-resistant polyester resin according to claim 10, wherein the oxidation stabilizer comprises at least one selected from the group consisting of hindered phenol-based oxidation stabilizers, phosphorous acid-based oxidation stabilizers, and thioether-based oxidation stabilizers, and the oxidation stabilizer is used in an amount of 50 ppm to 2,500 ppm based on the total weight of the high heat-resistant polyester resin.

13. The high heat-resistant polyester resin according to claim 10, wherein the branching agent comprises at least one selected from the group consisting of trimellitic anhydride, trimethylolpropane, and trimellitic acid, and the branching agent is used in an amount of 100 ppm to 2,500 ppm based on the total weight of the high heat-resistant polyester resin.

14. A method for preparing a high heat-resistant polyester resin according to claim 1, (a) A step of preparing a composition containing a diol component and an acid component, (b) The step of subjecting the composition to an esterification reaction at 200°C to 300°C, (c) The product of the esterification reaction is subjected to a polycondensation reaction at a temperature of 220°C to 350°C and under a reduced pressure of 0.01 mmHg to 600 mmHg for 1 to 24 hours. Methods that include...

15. A method for preparing a high heat-resistant polyester resin according to claim 14, wherein the molar ratio (G / A) of the diol component to the acid component added in step (a) is 1.10 to 3.

00.

16. A method for preparing a high heat-resistant polyester resin according to claim 14, wherein a catalyst is further added in step (a), and the catalyst comprises a germanium element or a tin element, or is a zinc-based catalyst.

17. A method for preparing a high heat-resistant polyester resin according to claim 14, wherein a stabilizer is further added in step (a), the stabilizer comprising at least one compound selected from the group consisting of phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and triethyl phosphonoacetate.

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