Polyester copolymer and preparation method and performance evaluation method thereof

Abstract

The invention discloses a polyester copolymer as well as a preparation method and a performance evaluation method thereof. The copolymer comprises residues of an aromatic dicarboxylic acid component from a mixture of terephthalic acid and isophthalic acid; and residues of a diol component from including cyclic diols having a boiling point greater than 270 DEG C, such as isosorbide (ISB), cyclohexanedimethanol (CHDM); and a linear long chain dihydric alcohol-1, 6-hexanediol (HOL) having a carbon-carbon length of greater than 4; the key performance of the obtained material is glass transition temperature (TG), the core performance of the obtained material is viscosity (VIS), and the important performance of the obtained material is chemical resistance (HAZ) and toughness elongation (REN). According to the material comprehensive application performance conformity, auxiliary prediction and evaluation can be carried out according to the target application performance and the influence weight thereof.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyester copolymers, and particularly relates to a polyester copolymer, a preparation method thereof, and a performance evaluation method thereof. Background Art

[0002] Traditional PET polyester materials have excellent mechanical strength and gas barrier properties, and are suitable as materials for beverage filling containers, packaging films, audio devices, video films, and the like, and have been widely used. The polyester sheets prepared from PET polyester materials also have excellent mechanical strength and are widely used as boxes, boxes, partitions, store shelves, protection boards, blister packages, building materials, interior materials, exterior materials, and the like.

[0003] In recent years, polyester materials have been widely used to prepare heat-resistant food or beverage containers, electronic product housings, such as in the fields of dishwashers, etc. Such usage scenarios require materials to have the characteristics of being resistant to detergent cleaning and a certain degree of heat resistance. In the emerging e-cigarette products in recent years, good chemical resistance to fogging, high toughness, and a certain degree of heat resistance are required. Generally, the heat resistance and chemical resistance characteristics increase with the increase of the crystallinity and intrinsic viscosity of the polyester, but as the crystallinity increases, the parts will become opaque.

[0004] Therefore, in order to obtain materials with higher heat resistance, chemical resistance, and high elongation toughness, and polyester with the characteristics of being transparent and non-fogging, third and fourth monomers, such as isosorbide (ISB), 1,4-cyclohexanedimethanol (CHDM), are usually introduced during its preparation process. However, introducing too much ISB monomer will make the polymerization of the material difficult, the toughness of the resin poor, and the chemical resistance performance decline, and a toughening monomer needs to be introduced. In this project, a long-chain diol monomer is introduced.

[0005] Therefore, there are relatively complex interactive effects in the above multi-monomer system. In order to better understand and evaluate the performance of the obtained copolyester material and whether it can meet the requirements of the above application fields, key indicators, core indicators, and important indicators can be classified according to the degree of influence of relevant performance on the application, and their corresponding influence weights can be proposed, in order to assist in evaluating the compliance of the material in the target application environment.

[0006] Therefore, there is a need in the actual product development and application for how to develop a copolyester resin containing heat-resistant monomers and toughening monomers and propose a comprehensive performance composite prediction model. Summary of the Invention

[0007] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, the abstract of the specification, and the title of the invention of this application to avoid obscuring the purpose of this part, the abstract of the specification, and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above and / or problems existing in the prior art, the present invention is proposed.

[0009] Therefore, an object of the present invention is to overcome the deficiencies in the prior art and provide a polyester copolymer.

[0010] To solve the above technical problems, the present invention provides the following technical solutions: including,

[0011] 1) Residues of the aromatic dicarboxylic acid component, which are composed of a mixture of terephthalic acid and isophthalic acid;

[0012] 2) Residues of the diol component, which are composed of a cyclic diol with a boiling point greater than 270 °C, a linear long-chain diol with a carbon-carbon length greater than 4, and an excessive amount of ethylene glycol monomer;

[0013] The molar ratio of alcohol to acid is 1.05 to 1.30.

[0014] Specifically, the term'residue' used herein means a specific part or unit that is included in the product of a chemical reaction and is derived from the specific compound when the specific compound participates in a chemical reaction. Specifically, the'residue' of the dicarboxylic acid component or the'residue' of the diol component respectively refers to the part derived from the dicarboxylic acid component or the diol component in the polyester copolymer formed by esterification or polycondensation.

[0015] Aromatic dicarboxylic acid component

[0016] The aromatic dicarboxylic acid component and the diol component used herein constitute the main monomers of the polyester copolymer. Aromatic dicarboxylic acids include terephthalic acid and isophthalic acid. By using this aromatic dicarboxylic acid, it is possible to make the copolyester maintain certain heat resistance and chemical resistance.

[0017] Diol component

[0018] The diol component herein belongs to the main monomers constituting the polyester copolymer. It includes cyclic or heterocyclic diols with relatively high boiling points, such as isosorbide and cyclohexanedimethanol, and long-chain flexible diols such as 1,6-hexanediol, neopentyl glycol, polyethylene glycol, and polycarbonate diol.

[0019] As a preferred embodiment of the polyester copolymer of the present invention, wherein: the cyclic / heterocyclic diol is isosorbide and cyclohexanedimethanol.

[0020] Specifically, due to its structural rigidity, isosorbide can be used to improve the temperature resistance characteristics of the prepared polyester copolymer. Due to the presence of internal hydrogen bonds in its structure, there are problems such as weak reactivity of this diol during the polymerization process. In the present invention, based on the molar ratio of the residue of the aromatic dicarboxylic acid component being 100%, the content of isosorbide residue is 5 to 30 mol%.

[0021] The cyclohexanedimethanol is 1,4 - cyclohexanedimethanol. There is a cyclohexane unit with certain rigidity and flexibility in its structure, which can improve the heat resistance and elongation toughness of the prepared copolyester material. At the same time, it is also found that increasing the cyclohexanedimethanol can also enhance the chemical erosion resistance of the material.

[0022] Preferably, calculated based on the residue molar ratio of the aromatic dicarboxylic acid component being 100%, the content of 1,4 - cyclohexanedimethanol residues is 40 - 90 mol%.

[0023] As a preferred embodiment of the polyester copolymer of the present invention, wherein: the linear long - chain diol includes one or more of 1,6 - hexanediol, neopentyl glycol, polyethylene glycol, polycarbonate diol, and polytetrahydrofuran diol.

[0024] Specifically, the linear long - chain diol, together with cyclohexanedimethanol, contributes to the high - toughness polyester copolymer component prepared. Here, the linear long - chain diol is a diol with more than C4, preferably 1,6 - hexanediol. Calculated based on the residue molar ratio of the aromatic dicarboxylic acid component being 100%, its content is 1 - 15 mol%.

[0025] As a preferred embodiment of the polyester copolymer of the present invention, wherein: the excess diol monomer is ethylene glycol.

[0026] As a preferred embodiment of the polyester copolymer of the present invention, wherein: calculated based on the residue molar ratio of the aromatic dicarboxylic acid component being 100%, the total molar number of the cyclic / heterocyclic diol is 50 mol% - 90 mol%, and the molar number of the linear long - chain diol is 1 mol% - 10 mol%.

[0027] As a preferred embodiment of the polyester copolymer of the present invention, wherein: in the cyclic diol with a boiling point greater than 270 °C, the molar number of cyclohexanedimethanol > 40 mol%.

[0028] Preferably, when calculated based on the residue molar ratio of the aromatic dicarboxylic acid component of the present invention being 100%, where the content of cyclohexanedimethanol residues is 40 mol% - 80 mol%, the content of isosorbide residues is 10 mol% - 30 mol%, and the molar number of the linear long - chain diol is 1 mol% - 10 mol%, the prepared polyester copolymer has excellent heat resistance, chemical resistance, elongation toughness, and transparency.

[0029] As a preferred embodiment of the polyester copolymer of the present invention, wherein: the polyester copolymer belongs to an amorphous - structured transparent polyester material with a crystallinity close to zero and has the following characteristics,

[0030] (i) The ductile elongation rate is 50% to 300%;

[0031] (ii) The glass transition temperature is 85°C to 110°C.

[0032] Another object of the present invention is to provide a method for preparing a polyester copolymer.

[0033] To solve the above technical problems, the present invention provides the following technical solutions: including,

[0034] The residue components of the aromatic dicarboxylic acid component and the residue of the glycol component are mixed and stirred, and an esterification catalyst and a stabilizer are added thereto to obtain a mixed component I. The mixed component I undergoes an esterification reaction to obtain an esterification melt;

[0035] Among them, the esterification reaction is carried out at a pressure of 0 kg / cm 2 to 5.0 kg / cm 2 and a temperature of 150°C to 270°C;

[0036] Furthermore, the esterification reaction conditions can be appropriately controlled according to the specific properties of the polyester to be prepared, the ratio of each component, or the process conditions, etc.

[0037] Preferably, the esterification reaction can be carried out at a pressure of 0.1 kg / cm 2 to 3.0 kg / cm 2 and a temperature of 220°C to 250°C.

[0038] A polycondensation catalyst is added to the esterification melt for polycondensation reaction. After the reaction is completed, it is cooled, pelletized, and granulated to obtain the polyester copolymer;

[0039] Among them, the polycondensation reaction is carried out at 200°C to 280°C and under a reduced pressure condition of 0.1 mmHg to 600 mmHg, and the reaction time is 2 to 10 hours.

[0040] As a preferred scheme of the method for preparing the polyester copolymer of the present invention, among them: the esterification catalyst is an esterification catalyst based on antimony compounds, organotin compounds, and titanate compounds, the stabilizer is a phosphorus-based compound, and the polycondensation catalyst includes one or more of titanium compounds, germanium compounds, antimony compounds, and tin compounds.

[0041] Specifically, the titanium compound component includes tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, titanium dioxide, and the like;

[0042] The germanium compound includes germanium dioxide, germanium glycolate, germanium acetate, or a mixture thereof;

[0043] The tin compound is: dibutyltin oxide, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate or a mixture thereof;

[0044] The antimony compound is: antimony glycolate, antimony trioxide, antimony acetate or a mixture thereof;

[0045] The phosphorus-based compound includes phosphoric acid, trimethyl phosphate, triethyl phosphate and the like, and the amount used (based on the amount of phosphorus element) is 10 ppm to 100 ppm.

[0046] Another object of the present invention is to provide an application of the polyester copolymer in the fields of electronic cigarettes and heat-resistant washable food containers.

[0047] Another object of the present invention is to provide a method for evaluating the properties of a polyester copolymer.

[0048] To solve the above technical problems, the present invention provides the following technical solutions: including,

[0049] Calculate the glass transition temperature Tg of the polyester copolymer according to formula (A);

[0050] Tg = 69.5 + X ISB ×0.9 + X CHDM ×0.15 - 0.5×X HOL Formula (A);

[0051] In the formula, X ISB , X CHDM , X HOL respectively represent the molar percentages of ISB, CHDM and HOL relative to 100 moles of aromatic dicarboxylic acid. The conformity coefficient is Tg / Tg0. The basic heat-resistant value Tg0 is specified according to actual application requirements, and its influence weight is defined as 20;

[0052] Calculate the anti-fogging degree grade value HAZ of the polyester copolymer according to formula (B);

[0054] HAZ = 10 - X CHDM ×0.12 + X ISB ×0.06 - (X HOL / 100) 0.29 ×3.7 Formula (B);

[0055] In the formula, X ISB , X CHDM , X HOL respectively represent the molar percentages of ISB, CHDM and HOL relative to 100 moles of aromatic dicarboxylic acid, and its influence weight is defined as 1;

[0056] Calculate the elongation REN of the polyester copolymer according to formula (C);

[0057] REN = 1.7×X CHDM + 7×X HOL - X ISB × 1.2 formula (C);

[0058] Wherein, X ISB 、X CHDM ,X HOL respectively represent the molar percentages of ISB, CHDM and HOL relative to 100 moles of aromatic dicarboxylic acid, and their influence weights are defined as 1;

[0059] When the actual viscosity VIS of the resin is greater than the base viscosity VIS0, its compliance coefficient is 1.0. If it is lower than the base viscosity requirement, the compliance coefficient is VIS / VIS0, and its influence weight is defined as 5;

[0060] Calculate the comprehensive application performance R of the polyester copolymer according to formula (D);

[0061] R = 100×(REN / REN0)×(HAZ / HAZ0)×Tg / Tg0 影响权权重20 ×if(VIS /

[0062] VIS0>1,1,VIS / VIS0 影响权重5 ;

[0063] When the R value is greater than 95, it can meet the overall application requirements in the fields of electronic cigarettes and heat-resistant washing food containers.

[0064] As a preferred scheme of the evaluation method for the performance of the polyester copolymer described in the present invention, wherein: when the basic application indexes of the material are Tg0>92°C, HAZ0<3 points, REN0>70%, and VIS>0.65, if the material indexes evaluated according to the evaluation method meet the basic application indexes, it meets its application requirements in the fields of electronic cigarettes and heat-resistant washing food containers.

[0065] Advantages of the present invention:

[0066] The copolyester resin product prepared according to the present invention has excellent elongation toughness, heat resistance, and chemical resistance. Various containers prepared therefrom can be used in fields such as heat-resistant and anti-washing dishwashers and electronic cigarettes to withstand high impact resistance, chemical corrosion resistance, and heat resistance requirements.

[0067] According to the evaluation method for the performance of the polyester copolymer provided by the present invention, auxiliary prediction and evaluation can be carried out according to the target application performance and its influence weight. Description of the Drawings

[0068] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings. Among them:

[0069] Figure 1 This is a comparison of the infrared absorption spectra of the copolyester prepared in Example 1 of the present invention and conventional PRT polyester. Specific embodiments

[0070] To make the above objects, features, and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention will be described in detail below in conjunction with the embodiments of the specification.

[0071] Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0072] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that excludes other embodiments.

[0073] The fluidity of the material prepared by the present invention is characterized by the intrinsic viscosity: its measurement method follows the "GB / T3401-2007" standard, dissolved by heating with a mixed solution of phenol-tetrachloroethane (1:1), and tested using an Ubbelohde viscometer in a thermostat at 35°C.

[0074] The heat resistance characteristics of the material are evaluated by the glass transition temperature Tg. A DSC I type differential scanning calorimeter is used to test the Tg of the obtained copolyester. The test conditions are as follows: analyze the enthalpy change of the copolyester sample under an environment where the nitrogen gas flow rate is 40 mL / min. First, heat 5-8 mg of the sample from room temperature to 280°C at a rate of 10°C / min and hold for 5 min to eliminate the thermal history; then cool to 25°C at a cooling rate of 10°C / min; subsequently, reheat to 275°C at a heating rate of 10°C / min to obtain the melting characteristics. Before the test, the sample is placed in a vacuum drying oven and vacuum dried at 70°C for 12 h.

[0075] The toughness of the material is evaluated by the elongation rate of the material. The measurement method is to use an Instron 5943 universal material testing machine produced by Instron Corporation of the United States for testing, carried out in accordance with the provisions of GB / T 1040.2 - 2006, and the tensile speed is 10 mm / min.

[0076] The chemical resistance characteristics of the material are evaluated by e - liquid impregnation. The test and evaluation method: The 2.0 - mm sheet injection - molded at a mold temperature of 55°C is in a transparent state. It is impregnated with e - liquid at 60°C for 168 hours, and its surface changes are observed, including haze change and cracking phenomenon. The chemical resistance characteristics are divided into grades 1 - 10. Grade 10 means white with cracks, grade 5 means slightly white with no micro - cracks, and grade 2 means the transparency remains basically unchanged.

[0077] Example 1

[0078] This example provides a preparation method of a polyester copolymer. Specifically:

[0079] 1) Esterification;

[0080] Add 2.857 kg of TPA / IPA (terephthalic acid / isophthalic acid, with a ratio of 20:1), 1.239 kg of CHDM (1,4 - cyclohexanedimethanol), 0.967 kg of ISB (isosorbide), 0.416 kg of EG (ethylene glycol), and 0.020 kg of HOL (1,6 - hexanediol) to a polyester synthesis reactor with a capacity of 30 L. At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 1. Stir for more than 1 hour until evenly mixed, and beat - disperse the aromatic dicarboxylic acid mixture (TPA / IPA) component. Calculated based on the mass of 100 parts of aromatic dicarboxylic acid, add 100 ppm of GeO 2 and 20 ppm of titanate as a catalyst, 25 ppm of phosphoric acid as a stabilizer;

[0081] Subsequently, add nitrogen to the reactor to form a pressurized state. The reactor pressure is 1.0 kgf / cm higher than the atmospheric pressure 2 , raise the reactor temperature to 220°C in 60 minutes, start esterification to produce water, then gradually raise it to 245°C, and keep the temperature at 245°C. The esterification lasts for 140 minutes until the molten ester becomes transparent. After the esterification is completed, reduce the pressure of the reactor to the atmospheric pressure to obtain an esterification melt.

[0082] 2) Polycondensation;

[0083] The esterification melt was placed in a polymerization reactor with a capacity of 30 L. The pressure of the reactor was reduced from atmospheric pressure to 5 Torr (absolute pressure: 5 mmHg) over 30 minutes, and the temperature of the reactor was raised to 260 °C over 1 hour. After the temperature reached 260 °C, polycondensation was carried out while gradually maintaining the pressure of the reactor at 1 Torr (absolute pressure: 1 mmHg) or less;

[0084] The stirring speed was set to fast. As the polycondensation proceeded, since the viscosity of the polymer increased, the stirring speed could be gradually reduced until the intrinsic viscosity (VIS) of the molten polymer in the reactor exceeded 0.65 dl / g or more. After the intrinsic viscosity of the molten polymer in the reactor reached the desired level, the melt was discharged through a die and a cooling water tank by high-pressure nitrogen, and pelletizing and granulation were carried out to obtain a polyester copolymer.

[0085] Figure 1 Curve 1 in [reference] is the infrared absorption spectrum of conventional polyester PET, and curve 2 is the infrared spectrum of the copolyester obtained by copolymerizing CHDM / ISB in this example. Among them, the peaks at 972.05 cm -1 , 1100.28 cm -1 in curve 2 are the characteristic peaks of ISB, and the peak intensity at 2800 cm -1 is significantly enhanced compared with the peak intensity of the conventional PET resin. This is because the -CH 2 - content of CHDM monomer in the copolyester is more than that of the conventional PET polyester. Therefore, the CHDM segment has been polymerized into the copolyester chain segment component. It can be seen that both ISB and CHDM have been polymerized into the copolyester structure.

[0086] Example 2

[0087] The difference between this example and Example 1 is that the raw material dosage in step 1) was adjusted to:

[0088] 2.847 kg of TPA (terephthalic acid), 1.235 kg of CHDM (1,4-cyclohexanedimethanol), 0.964 kg of ISB (isosorbide), 0.393 kg of EG (ethylene glycol), and 0.061 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 1;

[0089] The remaining steps were all referred to Example 1 to obtain the polyester copolymer of this example.

[0090] Example 3

[0091] The difference between this example and Example 1 is that the raw material dosage in step 1) was adjusted to:

[0092] 2.837 kg of TPA (terephthalic acid), 1.231 kg of CHDM (1,4 - cyclohexanedimethanol), 0.961 kg of ISB (isosorbide), 0.371 kg of EG (ethylene glycol), and 0.101 kg of HOL (1,6 - hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 1;

[0093] The remaining steps are all referred to Example 1 to obtain the polyester copolymer of this example.

[0094] Example 4

[0095] The difference between this example and Example 1 is that the raw material dosage in step 1) is adjusted to:

[0096] 2.813 kg of TPA (terephthalic acid), 1.220 kg of CHDM (1,4 - cyclohexanedimethanol), 0.952 kg of ISB (isosorbide), 0.315 kg of EG (ethylene glycol), and 0.200 kg of HOL (1,6 - hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 1;

[0097] The remaining steps are all referred to Example 1 to obtain the polyester copolymer of this example.

[0098] Comparative Example 1

[0099] The difference between this comparative example and Example 1 is that ISB and HOL are omitted, and the contents of other components are adaptively adjusted to:

[0100] 3.318 kg of TPA (terephthalic acid), 1.439 of CHDM (1,4 - cyclohexanedimethanol), 0.743 kg of EG (ethylene glycol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 1;

[0101] The remaining steps are all referred to Example 1 to obtain the polyester copolymer of this comparative example.

[0102] Comparative Example 2

[0103] The difference between this comparative example and Example 1 is that HOL is omitted, and the contents of other components are adaptively adjusted to:

[0104] 2.862 kg of TPA (terephthalic acid), 1.241 kg of CHDM (1,4 - cyclohexanedimethanol), 0.969 kg of ISB (isosorbide), 0.428 kg of EG (ethylene glycol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 1;

[0105] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this comparative example.

[0106] Table 1 Mole fractions of Examples 1 to 4 and Comparative Examples 1 and 2 based on 100 parts of aromatic dicarboxylic acid

[0107]

[0108] The relevant properties of the polyester copolymers prepared in Examples 1 to 4 and Comparative Examples 1 and 2 were measured, and the results are shown in Table 2.

[0109] Table 2 Performance comparison of polyester copolymers of Examples 1 to 4 and Comparative Examples 1 and 2

[0110]

[0111] As can be seen from Table 2, in the comparative examples, without the flexible long-chain diol HOL, adding a certain amount of HL can improve the toughness elongation of the material, while introducing the rigid diol ISB can significantly increase the glass transition temperature Tg of the copolyester.

[0112] Example 5

[0113] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0114] 2.767 kg of TPA / IPA (terephthalic acid / isophthalic acid, ratio 20:1), 1.440 kg of CHDM (1,4-cyclohexanedimethanol), 0.937 kg of ISB (isosorbide), 0.258 kg of EG (ethylene glycol), and 0.098 kg of HOL (1,6-hexanediol). At this time, the mole fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 3;

[0115] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this example.

[0116] Example 6

[0117] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0118] 2.700 kg of TPA / IPA (terephthalic acid / isophthalic acid, ratio 20:1), 1.639 kg of CHDM (1,4-cyclohexanedimethanol), 0.914 kg of ISB (isosorbide), 0.151 kg of EG (ethylene glycol), and 0.096 kg of HOL (1,6-hexanediol). At this time, the mole fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 3;

[0119] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this example.

[0120] Example 7

[0121] The difference between this example and Example 1 lies in adjusting the raw material dosages in step 1) to:

[0122] 2.801 kg of TPA / IPA (terephthalic acid / isophthalic acid, with a ratio of 20:1), 1.579 kg of CHDM (1,4-cyclohexanedimethanol), 0.711 kg of ISB (isosorbide), 0.209 kg of EG (ethylene glycol), and 0.199 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 3;

[0123] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this example.

[0124] Example 8

[0125] The difference between this example and Example 1 lies in adjusting the raw material dosages in step 1) to:

[0126] 2.755 kg of TPA / IPA (terephthalic acid / isophthalic acid, with a ratio of 20:1), 1.793 kg of CHDM (1,4-cyclohexanedimethanol), 0.700 kg of ISB (isosorbide), 0.154 kg of EG (ethylene glycol), and 0.098 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 3;

[0127] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this example.

[0128] Table 3 Molar Fractions of Examples 5 - 8 Based on 100 Parts of Aromatic Dicarboxylic Acid

[0129]

[0130]

[0131] Measure the relevant properties of those prepared in Examples 5 - 8, and the results are shown in Table 4.

[0132] Table 4 Performance Comparison of Polyester Copolymers in Examples 5 - 8

[0133]

[0134] When increasing the content of the HOL flexible long chain in the polyester copolymer, its heat-resistant glass transition temperature drops significantly, the toughness elongation rate REN increases significantly at the same time, and its chemical resistance characteristics are also improved to varying degrees.

[0135] Example 9

[0136] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0137] 2.707 kg of TPA / IPA (terephthalic acid / isophthalic acid, with a ratio of 20:1), 1.761 kg of CHDM (1,4-cyclohexanedimethanol), 0.687 kg of ISB (isosorbide), 0.152 kg of EG (ethylene glycol), and 0.192 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 5;

[0138] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this example.

[0139] Example 10

[0140] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0141] 2.594 kg of TPA / IPA (terephthalic acid / isophthalic acid, with a ratio of 20:1), 1.350 kg of CHDM (1,4-cyclohexanedimethanol), 1.318 kg of ISB (isosorbide), 0.145 kg of EG (ethylene glycol), and 0.092 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 5;

[0142] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this example.

[0143] Example 11

[0144] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0145] 2.887 kg of TPA / IPA (terephthalic acid / isophthalic acid, with a ratio of 20:1), 1.753 kg of CHDM (1,4-cyclohexanedimethanol), 0.489 kg of ISB (isosorbide), 0.270 kg of EG (ethylene glycol), and 0.103 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 5;

[0146] All the remaining steps refer to Example 1 to obtain the polyester copolymer of this example.

[0147] Example 12

[0148] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0149] 2.721 kg of TPA / IPA (terephthalic acid / isophthalic acid, ratio 20:1), 0.944 kg of CHDM (1,4-cyclohexanedimethanol), 1.382 kg of ISB (isosorbide), 0.356 kg of EG (ethylene glycol), and 0.097 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 5;

[0150] All the remaining steps refer to Example 1 to obtain the polyester copolymer of this example.

[0151] Example 13

[0152] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0153] 2.744 kg of TPA / IPA (terephthalic acid / isophthalic acid, ratio 20:1), 1.190 kg of CHDM (1,4-cyclohexanedimethanol), 1.161 kg of ISB (isosorbide), 0.307 kg of EG (ethylene glycol), and 0.098 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 5;

[0154] All the remaining steps refer to Example 1 to obtain the polyester copolymer of this example.

[0155] Example 14

[0156] The difference between this example and Example 1 lies in adjusting the raw material dosage in step 1) to:

[0157] 2.535 kg of TPA / IPA (terephthalic acid / isophthalic acid, ratio 20:1), 0.880 kg of CHDM (1,4-cyclohexanedimethanol), 1.716 kg of ISB (isosorbide), 0.189 kg of EG (ethylene glycol), and 0.180 kg of HOL (1,6-hexanediol). At this time, the molar fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 5;

[0158] All the remaining steps refer to Example 1 to obtain the polyester copolymer of this example.

[0159] Example 15

[0160] The difference between this example and Example 1 is that ISB is omitted and the raw material dosage in step 1) is adjusted to:

[0161] 3.251 kg of TPA / IPA (terephthalic acid / isophthalic acid, ratio 20:1), 1.410 kg of CHDM (1,4-cyclohexanedimethanol), 0.607 kg of EG (ethylene glycol), and 0.231 kg of HOL (1,6-hexanediol). At this time, the mole fractions of each component based on 100 parts of aromatic dicarboxylic acid (TPA / IPA) are shown in Table 5;

[0162] For the remaining steps, refer to Example 1 to obtain the polyester copolymer of this example.

[0163] Table 5 Mole fractions of Examples 9 - 15 based on 100 parts of aromatic dicarboxylic acid

[0164]

[0165] The relevant properties of the polyester copolymers prepared in Examples 9 - 15 were measured, and the results are shown in Table 6.

[0166] Table 6 Performance comparison of polyester copolymers in Examples 5 - 8

[0167]

[0168]

[0169] As can be seen from Table 6, when the molar ratio of the rigid ISB diol exceeds 30%, although there is still an improvement effect on the glass transition temperature resistance of the polyester copolymer, the final viscosity of the copolyester cannot be further increased. Usually, the polymerization reaction reaches equilibrium when it reaches about 0.60. A lower viscosity resin means a lower molecular weight of the material, and its toughness and chemical resistance characteristics are both insufficient.

[0170] Example 16

[0171] This example provides a method for evaluating the main properties of a polyester copolymer. Specifically:

[0172] The heat resistance of the polyester copolymer is characterized by the glass transition temperature Tg, and the influence weight is 20. Tg satisfies Equation (A):

[0173] Tg = 69.5 + X ISB ×0.9 + X CHDM ×0.15 - 0.5×X HOL Equation (A);

[0174] In the formula, X ISB 、X CHDM, X HOL respectively represent the molar percentages of ISB, CHDM, and HOL relative to 100 moles of aromatic dicarboxylic acid. Its compliance coefficient is Tg / Tg0, and the basic heat resistance value Tg0 is specified according to the actual application requirements;

[0175] Generally, Tg0 greater than 92 °C can meet the application requirements;

[0176] The chemical resistance of the polyester copolymer is characterized by the anti-fogging degree rating value HAZ, with an influence weight of 1. HAZ satisfies Equation (B):

[0178] HAZ = 10 - X CHDM × 0.12 + X ISB × 0.06 - (X HOL / 100) 0.29 × 3.7 Equation (B);

[0179] Generally, when HAZ0 reaches 3 points, it can meet most applications;

[0180] The toughness of the copolyester is characterized by the elongation REN, with an influence weight of 1. REN satisfies Equation (C):

[0181] REN = 1.7 × X CHDM + 7 × X HOL - X ISB × 1.2 Equation (C);

[0182] Generally, the elongation at break of the toughness of the copolyester REN > 70%, which can meet most application requirements;

[0183] The influence weight of the viscosity flow characteristic parameter of the polyester copolymer is 5. When the actual viscosity VIS of the resin is greater than the basic viscosity VIS0, its compliance coefficient is 1.0. If it is lower than the basic viscosity requirement, the compliance coefficient is VIS / VIS0;

[0184] When the resin viscosity is greater than 0.65, it can meet the requirements of most processing applications;

[0185] The comprehensive application performance of the polyester copolymer is R, and it satisfies Equation (D):

[0186] R = 100 × (elongation toughness REN / RENO) × (HAZ / HAZO) × Tg / Tg0 影响权重20

[0187] × if(VIS / VISO > 1, 1, VIS / VISO 影响权重5 ;

[0188] In the invention, when the R value is greater than 95, it can generally meet the overall application requirements.

[0189] The main properties of the polyester copolymer were evaluated using the evaluation method of this embodiment and compared with the measured properties. The results are shown in Table 7.

[0190] Table 7 Comparison of Measured and Evaluated Values of Main Properties of the Copolymer

[0191]

[0192]

[0193] As can be seen from Table 7, the evaluation method for the main properties of the polyester copolymer provided by the present invention is basically consistent with the measured values, indicating the accuracy of the evaluation model of the present invention. According to the target application performance and its influence weight, the evaluation model of the present invention can be used for auxiliary prediction and evaluation.

[0194] In summary, the copolyester resin product prepared according to the present invention has excellent elongation toughness, heat resistance, and chemical resistance. A variety of containers prepared therefrom can be used in fields such as dishwashers and electronic cigarettes that are resistant to temperature and washing to withstand high impact resistance, chemical corrosion resistance, and temperature requirements.

[0195] According to the evaluation method for the properties of the polyester copolymer provided by the present invention, auxiliary prediction and evaluation can be carried out according to the target application performance and its influence weight.

[0196] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A polyester copolymer, characterized in that: include, 1) The residue of an aromatic dicarboxylic acid component, which is composed of a mixture of terephthalic acid and isophthalic acid; 2) the residue of the diol component, which is composed of a cyclic diol having a boiling point greater than 270°C, a linear long-chain diol having a carbon-carbon length greater than 4, and an excess of ethylene glycol monomer; The molar ratio of alkyd to acid is 1.05 to 1.

30.

2. The polyester copolymer according to claim 1, characterized in that: The cyclic diols are isosorbide and cyclohexanedimethanol, the linear long-chain diols include one or more of 1,6-hexanediol, neopentyl glycol, polyethylene glycol, polycarbonate diol, polytetrahydrofuran diol, and the diol monomer is ethylene glycol.

3. The polyester copolymer according to claim 2, characterized in that: Calculated based on the molar ratio of the residue of the aromatic dicarboxylic acid component as 100%, the total molar number of the cyclic diol is 50 mol% to 90 mol%, and the molar number of the linear long-chain diol is 1 mol% to 10 mol%.

4. The polyester copolymer according to claim 5, characterized in that: The molar number of cyclohexanedimethanol in the cyclic diol with a boiling point greater than 270° C. is greater than 40 mol %.

5. The polyester copolymer according to any one of claims 1 to 4, characterized in that: The polyester copolymer is a transparent polyester material with an amorphous structure, a crystallinity close to zero, and has the following characteristics: (i) Toughness elongation is 50% to 300%; (ii) The glass transition temperature is 85°C to 110°C.

6. The method for preparing a polyester copolymer according to claim 5, wherein: include, The residues of the aromatic dicarboxylic acid component and the diol component are mixed and stirred, and an esterification catalyst and a stabilizer are added thereto to obtain a mixed component I. The mixed component I is subjected to an esterification reaction to obtain an esterified melt; Wherein, the esterification reaction is carried out at 0kg / cm 2 ~5.0kg / cm 2 The reaction is carried out under pressure and at a temperature of 150°C to 270°C; Adding a polycondensation catalyst to the esterification melt to carry out a polycondensation reaction, cooling, pelletizing and granulating after the reaction is completed, thereby obtaining a polyester copolymer; The polycondensation reaction is carried out under reduced pressure conditions of 200°C to 280°C and 0.1 mmHg to 600 mmHg, and the reaction time is 2 to 10 hours.

7. The method for preparing a polyester copolymer according to claim 6, wherein: The esterification catalyst includes an esterification catalyst based on a titanate compound or at least one of zinc acetate, cobalt acetate, tetrabutyl titanate, antimony trioxide, isopropyl titanate, antimony glycol, and dibutyltin oxide; The stabilizer is a phosphorus-based compound, and the polycondensation catalyst includes one or more of a titanium compound, a germanium compound, an antimony compound, and a tin compound.

8. Use of the polyester copolymer according to claim 7 in the fields of electronic cigarettes and food containers resistant to temperature washing.

9. A method for evaluating the performance of a polyester copolymer, characterized in that: include, The glass transition temperature Tg of the polyester copolymer is calculated according to formula (A); Tg = 69.5 + X ISB × 0.9 + X CHDM × 0.15 - 0.5 × X HOL Equation (A); In the formula, X ISB , X CHDM , X HOL They represent the molar percentage of ISB, CHDM and HOL relative to 100 parts by mole of aromatic dibasic acid, respectively. The compliance coefficient is Tg / Tg0. The basic temperature resistance value Tg0 is specified according to the actual application requirements, and the influence weight is defined as 20. The anti-haze grade value HAZ of the polyester copolymer is calculated according to formula (B); HAZ = 10 - X CHDM × 0.12 + X ISB × 0.06 - (X HOL / 100) 0.29 × Equation (B) of 3.7; Where, X ISB , X CHDM , X HOL They represent the molar percentages of ISB, CHDM and HOL relative to 100 moles of aromatic dibasic acid, respectively, and their influence weights are defined as 1; The elongation REN of the polyester copolymer is calculated according to formula (C); REN=1.7×X CHDM +7×X HOL -X ISB ×1.2 formula (C); Where, X ISB , X CHDM , X HOL They represent the molar percentages of ISB, CHDM and HOL relative to 100 moles of aromatic dibasic acid, respectively, and their influence weights are defined as 1; When the actual viscosity VIS of the resin is greater than the basic viscosity VIS0, its compliance coefficient is 1.

0. If it is lower than the basic viscosity requirement, the compliance coefficient is VIS / VIS0, and its impact weight is defined as 5; The comprehensive application performance R of the polyester copolymer is calculated according to formula (D); R=100×(REN / REN0)×(HAZ / HAZ0)×Tg / Tg0 影响权权重20 ×if(VIS / SHOW0>1,1,SHOW / SHOW0 影响权重5 ; When the R value is greater than 95, it can meet the overall application requirements in the field of electronic cigarettes and temperature-resistant washing food containers.

10. The method for evaluating the performance of a polyester copolymer according to claim 9, wherein: When the basic application indicators of the material are Tg0>92°C, HAZ0<3 points, REN0>70%, and VIS>0.65, the material indicators evaluated according to the evaluation method meet the basic application indicators, that is, they meet the application requirements in the fields of electronic cigarettes and temperature-resistant washing food containers.

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