Polyester materials, methods of making and using the same

Abstract

The present application relates to a polymer material, discloses a polyester material and a preparation method and application thereof. The polyester material is a polymer containing structural unit A shown in formula (I) and structural unit B shown in formula (II); wherein R1, R2 and R3 are each independently hydrogen, hydroxyl or C1-C6 alkyl, R4 is C1-C6 alkyl or hydrogen, R6, R7, R8 and R9 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer of 3-20. The preparation method comprises: (1) mixing dihydric alcohol monomers, diacid monomers, modified monomers and a catalyst under esterification reaction conditions to perform a first stage reaction to obtain a prepolymer; the modified monomers include dihydric alcohol containing the structure shown in formula (I) and diacid containing the structure shown in formula (II); (2) performing a second stage reaction on the prepolymer under polycondensation reaction conditions. The polyester material can effectively reduce the melting point while avoiding the decrease of glass transition temperature.

Description

Technical Field

[0001] This invention relates to polyester materials, specifically to a polyester material, its preparation method, and its applications. Background Technology

[0002] Polybutylene terephthalate (PBT) is a semi-crystalline thermoplastic polyester and an engineering plastic with excellent overall properties. PBT has good processing performance and a faster crystallization rate compared to PET resin. PBT products have excellent electrical and mechanical properties and are widely used in electronic products, daily necessities, automobiles, and other fields.

[0003] With the expanding applications of PBT, PBT nonwoven fabrics are widely used in various filter materials, such as air filters, vehicle fuel system filters, and water filters. PBT nonwoven fabrics demonstrate significantly better performance than PET nonwoven fabrics. Conventional PBT, due to its high melting point, cannot be used to produce nonwoven PBT materials; PBT with a lower melting point must be used, below 170℃, with an optimal melting point of 150-170℃. Due to the specific nature of the production equipment, the PBT used for nonwoven fabric production not only needs a low melting point but also requires a relatively high glass transition temperature. This is because PBT with a low glass transition temperature easily clogs the nozzles of the spray gun. Currently, ordinary low-melting-point PBT on the market requires periodic shutdowns to clean the spray gun nozzles.

[0004] In existing technologies, other comonomers are added during the PBT production process. The addition of these comonomers can disrupt the regularity of the PBT macromolecular chains, reducing its crystallinity and thus lowering its melting point; however, it also leads to a decrease in the glass transition temperature of PBT, making it lower than that of conventional PBT. For example, CN102344554A discloses a method for preparing a low-melting-point PBT copolyester, where phthalic acid includes terephthalic acid and isophthalic acid. However, the PBT prepared by this method, while reducing its crystallinity and melting point, also results in a decrease in its glass transition temperature.

[0005] The current method for preparing low-melting-point polyester is to add some monomers for copolymerization modification. These monomers mainly include isophthalic acid, adipic acid, ethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, and 2,2-methyl-1,3-propanediol. The addition of these monomers reduces the crystallinity and melting point of PBT, while also causing its glass transition temperature to decrease. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem that existing polyester materials, while lowering the melting point, also cause a decrease in the glass transition temperature, and to provide a polyester material, its preparation method, and its application.

[0007] During the research process, the inventors of this invention unexpectedly discovered that the presence of structural unit A as shown in formula (I) and structural unit B as shown in formula (II) in the polymer can effectively reduce the melting point of the polyester material while avoiding a decrease in its glass transition temperature. In fact, it can even effectively reduce the melting point of the polyester material while increasing its glass transition temperature. This can reduce the possibility of nozzle clogging during the spinning process or the melt-blown nonwoven fabric preparation process, and facilitate its subsequent application in spinning or the melt-blown nonwoven fabric preparation process.

[0008] To achieve the above objectives, the first aspect of the present invention provides a polyester material, which is a polymer containing structural unit A as shown in formula (I) and structural unit B as shown in formula (II);

[0009]

[0010]

[0011] In this context, R1, R2, and R3 are each independently hydrogen, hydroxyl, or C1-C6 alkyl, R4 is C1-C6 alkyl or hydrogen, R6, R7, R8, and R9 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer from 3 to 20.

[0012] A second aspect of the present invention provides a method for preparing a polyester material, comprising the following steps:

[0013] (1) Under esterification reaction conditions, diol monomers, diacid monomers, modified monomers and catalysts are mixed to carry out the first stage reaction to obtain prepolymers;

[0014] The modified monomers include diols containing the structure shown in formula (I) and dicarboxylic acids containing the structure shown in formula (II);

[0015]

[0016] Wherein, R1, R2 and R3 are each independently hydrogen, hydroxyl or C1-C6 alkyl, R4 is C1-C6 alkyl or hydrogen, R6, R7, R8 and R9 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer from 3 to 20;

[0017] (2) Under polycondensation reaction conditions, the prepolymer is subjected to a second-stage reaction.

[0018] The third aspect of the present invention provides the application of the aforementioned polyester material or the polyester material prepared by the aforementioned preparation method in spinning.

[0019] The polyester material provided by this invention is a polymer containing structural unit A as shown in formula (I) and structural unit B as shown in formula (II). It can effectively reduce the melting point of the polyester material while avoiding a decrease in the glass transition temperature, and even effectively reduce the melting point of the polyester material while increasing its glass transition temperature. This can reduce the possibility of nozzle clogging during the spinning process or the melt-blown nonwoven fabric preparation process, and facilitate its subsequent application in spinning or the preparation of nonwoven fabrics using the melt-blown method.

[0020] Taking PBT material as an example, when PBT contains the above-mentioned structural unit A and structural unit B, the melting point of PBT can reach as low as 150℃. Compared with conventional PBT, its glass transition temperature is also improved, which can reduce the possibility of nozzle clogging during spinning or meltblown nonwoven fabric preparation, and facilitate its subsequent application in spinning or meltblown nonwoven fabric preparation. Detailed Implementation

[0021] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0022] As previously stated, the first aspect of the present invention provides a polyester material, which is a polymer containing structural unit A of formula (I) and structural unit B of formula (II);

[0023]

[0024] In this context, R1, R2, and R3 are each independently hydrogen, hydroxyl, or C1-C6 alkyl, R4 is C1-C6 alkyl or hydrogen, R6, R7, R8, and R9 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer from 3 to 20.

[0025] According to the present invention, R1, R2, and R3 can each independently be hydrogen, hydroxyl, straight-chain C1-C6 alkyl, branched C1-C6 alkyl, or C1-C6 cycloalkyl, for example, hydrogen, hydroxyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-ethylpropyl, 2,2-dimethylpropyl, cyclopropyl, and cyclobutyl, etc. R4 can be hydrogen, straight-chain C1-C6 alkyl, branched C1-C6 alkyl, or C1-C6 cycloalkyl. For example, it can be hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-ethylpropyl, 2,2-dimethylpropyl, cyclopropyl, and cyclobutyl, etc. R6, R7, R8, and R9 can each independently be hydrogen, straight-chain C1-C6 alkyl, branched C1-C6 alkyl, or C1-C6 cycloalkyl, for example, it can be hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-ethylpropyl, 2,2-dimethylpropyl, cyclopropyl, and cyclobutyl, etc.

[0026] The aforementioned structural unit A and structural unit B can be obtained by infrared and nuclear magnetic resonance analysis of polyester materials.

[0027] The polyester material provided by this invention is a polymer containing structural unit A shown in formula (I) and structural unit B shown in formula (II). Under the action of the above two structural units, the melting point of the polyester material can be effectively reduced while avoiding the decrease of the glass transition temperature. In fact, the melting point of the polyester material can be effectively reduced while increasing its glass transition temperature. This reduces the possibility of nozzle clogging during the spinning process or the melt-blown nonwoven fabric preparation process, and facilitates its subsequent application in spinning or the melt-blown nonwoven fabric preparation process.

[0028] Preferably, R1 is hydrogen or a hydroxyl group, R2 and R3 are each independently hydrogen or a C1-C6 alkyl group, and n is a positive integer from 3 to 15. Limiting R1, R2, and R3 to the above ranges further reduces the melting point of the polyester. Further preferably, considering the ability to further reduce the melting point of the polyester, R2, R3, R4, R6, R7, R8, and R9 are each independently hydrogen or a methyl group, and n is a positive integer from 3 to 10. More preferably, R2, R3, R4, R6, R7, R8, and R9 are hydrogen.

[0029] Preferably, the polymer further comprises structural unit C as shown in formula (III) and structural unit D as shown in formula (IV);

[0030]

[0031] Among them, R 10 R 11 R 12 and R 13 Each is independently a C1-C6 alkyl or hydrogen, and R5 is a C2-C10 alkylene. Specifically, R 10 R 11 R 12 and R 13 Each of the following can be independently hydrogen, a straight-chain alkyl group, a branched alkyl group, or a cycloalkyl group, specifically hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-ethylpropyl, 2,2-dimethylpropyl, cyclopropyl, and cyclobutyl, etc.; R5 can be a C2-C10 straight-chain alkylene group or a C2-C10 branched alkylene group. Studies have shown that the polymer provided above contains both structural unit C and structural unit D, which can further reduce the melting point of the polyester material. Further preferably, considering the ability to further reduce the melting point of the polyester material, R... 10 R 11 R 12 and R 13 Each is independently methyl or hydrogen, and R5 is a C2-C6 alkylene group. More preferably, R... 10 R 11 R 12 and R 13 The R5 is hydrogen, and it is a C2-C4 alkylene group.

[0032] Preferably, in the polymer, the weight percentage of structural unit A is 1-8.5%, specifically 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 8.5%, or any value between these values; the molar amount of structural unit B accounts for 10-75% of the total molar amount of structural unit B and structural unit C, specifically 10%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, or any value between these values. Studies have found that controlling the content of structural unit A and structural unit B within the above range can further improve the interaction effect between structural unit A and structural unit B, thereby further reducing the melting point of the polyester material while further increasing the glass transition temperature of the polyester material.

[0033] Specifically, the weight percentage of structural unit A and the molar percentage of structural unit B can be calculated by measuring using nuclear magnetic resonance or gas chromatography.

[0034] Preferably, the polyester material has a melting point less than or equal to 215°C and a glass transition temperature of 34°C, which reduces the possibility of nozzle clogging during melting and facilitates its subsequent application in the preparation of nonwoven fabrics using the melt-blown method. More preferably, the polyester material has a melting point less than or equal to 190°C and a glass transition temperature of 36-80°C.

[0035] According to the present invention, the melting point and glass transition temperature are measured using a differential scanning calorimeter (DSC8500) from PE Corporation. The process of calculating the glass transition temperature using differential scanning calorimetry (DSC) includes: under nitrogen protection, using DSC thermal analysis, the temperature is increased from 25°C to 290°C at a heating rate of 10°C / min, held for 5 min, then decreased to 25°C at a rate of 400°C / min, then increased again from 25°C to 290°C at a heating rate of 10°C / min, held for 5 min, and finally decreased to 100°C at a rate of 10°C / min. The glass transition temperature (Tg) and melting point (Tm) are calculated based on the second heating curve.

[0036] Preferably, the terminal carboxyl groups of the polyester material are 20-38 mol / t, and the intrinsic viscosity is 0.7-1 dL / g, which further facilitates its subsequent application in the preparation of nonwoven fabrics using the meltblown method.

[0037] According to the present invention, the intrinsic viscosity is tested and characterized in accordance with 5.1 of GB / T14190-2017 Test Method for Fiber Grade Polyester Chips, and the terminal carboxyl groups are tested and characterized in accordance with 5.4 of GB / T14190-2017 Test Method for Fiber Grade Polyester Chips.

[0038] A second aspect of the present invention provides a method for preparing a polyester material, comprising the following steps:

[0039] (1) Under esterification reaction conditions, diol monomers, diacid monomers, modified monomers and catalysts are mixed to carry out the first stage reaction to obtain prepolymers;

[0040] The modified monomers include diols containing the structure shown in formula (I) and dicarboxylic acids containing the structure shown in formula (II);

[0041]

[0042]

[0043] Wherein, R1, R2 and R3 are each independently hydrogen, hydroxyl or C1-C6 alkyl, R4 is C1-C6 alkyl or hydrogen, R6, R7, R8 and R9 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer from 3 to 20;

[0044] (2) Under polycondensation reaction conditions, the prepolymer is subjected to a second-stage reaction.

[0045] Specifically, the structure of the diol containing the structure shown in formula (I) is as follows:

[0046] In this context, R1, R2, and R3 are each independently hydrogen, hydroxyl, or C1-C6 alkyl, R4 is a C1-C6 alkyl or hydrogen, and n is a positive integer from 3 to 20.

[0047] The following are dicarboxylic acids containing the structure shown in formula (II):

[0048] R6, R7, R8 and R9 are each independently hydrogen or C1-C6 alkyl.

[0049] According to the present invention, R1, R2, and R3 can each independently be hydrogen, hydroxyl, straight-chain C1-C6 alkyl, branched C1-C6 alkyl, or C1-C6 cycloalkyl, for example, hydrogen, hydroxyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-ethylpropyl, 2,2-dimethylpropyl, cyclopropyl, and cyclobutyl, etc. R4 can be hydrogen, straight-chain C1-C6 alkyl, branched C1-C6 alkyl, or C1-C6 cycloalkyl. For example, it can be hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-ethylpropyl, 2,2-dimethylpropyl, cyclopropyl, and cyclobutyl, etc. R6, R7, R8, and R9 can each independently be hydrogen, straight-chain C1-C6 alkyl, branched C1-C6 alkyl, or C1-C6 cycloalkyl, for example, it can be hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-ethylpropyl, 2,2-dimethylpropyl, cyclopropyl, and cyclobutyl, etc. The termination condition for the first stage reaction can be determined by the experimenter based on the actual situation; preferably, it can be determined based on the amount of water in the product. In a specific embodiment of the present invention, the termination condition for the first stage reaction is: the esterification reaction ends when the amount of water collected reaches 90% of the theoretical value.

[0050] The termination condition for the second-stage reaction can also be determined by the experimenter based on the actual situation. Preferably, it can be determined based on the viscosity of the reaction system or whether the stirring current reaches the rated value. In a specific embodiment of the present invention, the termination condition for the second-stage reaction is: the stirring current reaches the rated value.

[0051] During the research process, the inventors discovered that the polyester material prepared by the above preparation method can effectively reduce the melting point of the polyester material while avoiding the reduction of the glass transition temperature. This reduces the possibility of nozzle clogging during the spinning process or the melt-blown nonwoven fabric preparation process, facilitating its subsequent application in spinning or the melt-blown nonwoven fabric preparation process.

[0052] Preferably, R1 is hydrogen, hydroxyl, or C1-C6 hydroxyalkyl, R2 and R3 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer from 3 to 15. Within the above range, the melting point of the polyester material can be further reduced. From the perspective of further reducing the melting point of the polyester material, preferably, R1 is hydrogen or hydroxyl, R2, R3, R4, R6, R7, R8, and R9 are each independently hydrogen or methyl, and n is a positive integer from 3 to 10. More preferably, R2, R3, R4, R6, R7, R8, and R9 are hydrogen.

[0053] Preferably, the dicarboxylic acid monomer is a dicarboxylic acid containing the structure shown in formula (III), and the diol monomer is a diol containing the structure shown in formula (IV);

[0054]

[0055] Among them, R 10 R 11 R 12 and R 13 Each of the components is independently C1-C6 alkyl or hydrogen, and R5 is C2-C10 alkylene. Studies have shown that including a dicarboxylic acid containing the structure shown in formula (III) and a diol containing the structure shown in formula (IV) in the comonomer can further reduce the melting point of the polyester material. Further preferably, considering the ability to further reduce the melting point of the polyester material, the R... 10 R 11 R 12 and R 13 Each of the components is independently C1-C4 alkyl or hydrogen, and R5 is C2-C6 alkylene. More preferably, R... 10 R 11 R 12 and R 13 Each is independently methyl or hydrogen. More preferably, the R10 R 11 R 12 and R 13 The R5 is hydrogen, and it is a C2-C4 alkylene group.

[0056] Specifically, the structural formulas of the dicarboxylic acid containing the structure shown in formula (III) and the diol containing the structure shown in formula (IV) are as follows:

[0057] HO-R5-OH, where R 10 R 11 R 12 and R 13 Each is independently a C1-C6 alkyl or hydrogen, and R5 is a C2-C10 alkylene.

[0058] Preferably, in step (1), the weight ratio of the diol containing the structure shown in formula (I) to the diacid containing the structural unit shown in formula (II) is 1:1-80, preferably 1:1-20, and more preferably 1:5-10. More preferably, in step (1), relative to 100g of the diacid monomer, the amount of the diol monomer added is 80-260g, the amount of the modified monomer added is 10-280g, and the amount of the catalyst added is 0.03-0.3g; the polyester material obtained under the above conditions has a lower melting point. Preferably, the catalyst is a titanate catalyst and / or an antimony-containing catalyst, specifically any catalyst containing a titanate structure or an antimony-containing catalyst. More preferably, the titanate catalyst is tetrabutyl titanate and / or tetraethyl titanate, and the antimony-containing catalyst is selected from at least one of antimony glycolate, antimony acetate, and antimony trioxide.

[0059] Preferably, in step (1), the esterification reaction conditions include at least: oxygen isolation, and a temperature of 180℃-260℃, specifically 180℃, 200℃, 220℃, 240℃, 260℃, or any value between the aforementioned values. Under these conditions, the diol monomer, diacid monomer, and modified monomer exhibit better esterification effects, thereby further reducing the melting point of the subsequently obtained polyester. Oxygen isolation is typically achieved by introducing an inert gas such as nitrogen or helium into the reaction system. The first-stage reaction is carried out under stirring conditions, and the stirring rate can be determined by the experimenter based on the actual situation.

[0060] Preferably, in step (2), the polycondensation reaction conditions include at least: a temperature of 245-290°C, specifically 245°C, 255°C, 265°C, 275°C, 285°C, 290°C, or any value between the aforementioned values; and an absolute vacuum of less than 100 Pa. Under these conditions, the ester monomers obtained by the above esterification have a better polycondensation effect, which can further reduce the melting point of the subsequently produced polyester.

[0061] According to the present invention, the cooling rate is 0.6-1.5℃ / min before reaching the polycondensation reaction conditions.

[0062] The third aspect of the present invention provides the application of the above-described polyester material or the polyester material prepared by the above-described preparation method in spinning.

[0063] Preferably, the third aspect of the present invention provides the application of the above-described polyester material or the polyester material prepared by the above-described preparation method in the meltblown method for preparing nonwoven fabrics.

[0064] The aforementioned polyester material has a low melting point while also increasing its glass transition temperature, making it well-suited for applications in spinning or nonwoven fabric preparation. It does not clog nozzles and reduces the difficulty of preparation.

[0065] According to a particularly preferred embodiment of the present invention, the method for preparing the aliphatic-aromatic polyester includes the following steps:

[0066] (1) Stir and slurry the diol containing the structure shown in formula (I), the dicarboxylic acid containing the structure shown in formula (II), the dicarboxylic acid containing the structure shown in formula (III), the diol containing the structure shown in formula (IV), and the catalyst. After nitrogen purging three times, heat the mixture to 180-260℃ and esterify it under normal pressure. When the amount of water produced by esterification reaches 90% of the theoretical amount, the esterification is terminated.

[0067]

[0068]

[0069] Among them, R1, R2, and R3 are each independently hydrogen, hydroxyl, or C1-C6 alkyl, and R4, R6, R7, R8, R9, R 10 R 11 R 12 and R 13Each is independently a C1-C6 alkyl or hydrogen, R5 is a C2-C10 alkylene, and n is 3-20; the weight ratio of the diol containing the structure shown in formula (I) to the diacid containing the structural unit shown in formula (II) is 1:1-80; relative to 100g of the diacid containing the structure shown in formula (III), the amount of the diol containing the structure shown in formula (IV) added is 80-260g; the total amount of the diol containing the structure shown in formula (I) and the diacid containing the structural unit shown in formula (II) added is 10-280g; and the amount of the catalyst added is 0.03-0.3g.

[0070] (2) Reduce the pressure and heat the above esterification product for 45 minutes to make its temperature 245-290℃ and vacuum degree less than 100Pa, and enter the high vacuum polycondensation stage. When the stirring current reaches the rated value, the material is discharged to obtain polyester material.

[0071] The polyester material prepared by the above method has a low melting point while also increasing its glass transition temperature, making it suitable for applications in spinning or nonwoven fabric preparation. It does not clog nozzles and reduces preparation difficulty. Furthermore, it provides a new method for preparing low-melting-point polyesters.

[0072] The present invention will be described in detail below through embodiments.

[0073] In the following embodiments, the detection methods for each parameter and performance are as follows:

[0074] (1) The glass transition temperature and melting point were calculated by differential scanning calorimetry (DSC). The specific process was as follows: under nitrogen protection, DSC thermal analysis was used to raise the temperature from 25℃ to 290℃ at a rate of 10℃ / min and hold for 5min. Then, the temperature was lowered to 25℃ at a rate of 400℃ / min. Then, the temperature was raised from 25℃ to 290℃ at a rate of 10℃ / min and held for 5min. Finally, the temperature was lowered to 100℃ at a rate of 10℃ / min. The glass transition temperature Tg and melting point Tm were calculated based on the second heating curve.

[0075] (2) The intrinsic viscosity was tested in accordance with section 5.1 of GB / T14190-2017 Test Method for Fiber Grade Polyester Chips.

[0076] (3) The terminal carboxyl group was tested according to the method of GB / T14190-2017.

[0077] (4) Breathability is tested according to the method of GB / T5453.

[0078] (5) The fracture strength shall be tested in accordance with the method of GB / T3923.1.

[0079] (6) The original air resistance was tested according to the method of GOSTR ISO11092:2012.

[0080] (7) The weight percentage of structural unit A was calculated by NMR measurement.

[0081] (8) The molar percentage of structural unit B was calculated by gas chromatography.

[0082] In the following examples, the linear condensate of phenol and formaldehyde (A) has the chemical formula shown in formula (V).

[0083]

[0084] The chemical formula of the linear condensate of phenol and formaldehyde (C) is shown in formula (VI).

[0085]

[0086] The chemical formula of the linear condensate of phenol and formaldehyde (D) is shown in formula (VII).

[0087]

[0088] The chemical formula of the linear condensate of resorcinol and formaldehyde (B) is shown in formula (VIII).

[0089]

[0090] The chemical formula of the linear condensate of resorcinol and formaldehyde (E) is shown in formula (IX).

[0091]

[0092] All the linear condensates mentioned above were obtained commercially, and the remaining raw materials were chemically pure.

[0093] Example 1

[0094] 315g of terephthalic acid, 35g of isophthalic acid, 4.7g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0095] Example 2

[0096] 280g of terephthalic acid, 70g of isophthalic acid, 10g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0097] Example 3

[0098] 250g of terephthalic acid, 100g of isophthalic acid, 14.5g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0099] Example 4

[0100] 210g of terephthalic acid, 140g of isophthalic acid, 20g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0101] Example 5

[0102] 175g of terephthalic acid, 175g of isophthalic acid, 24g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0103] Example 6

[0104] 140g of terephthalic acid, 210g of isophthalic acid, 28g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0105] Example 7

[0106] In a 20L reactor, 2kg of terephthalic acid, 3kg of isophthalic acid, 3kg of ethylene glycol, 47g of resorcinol, formaldehyde linear condensate (B), and 3g of antimony glycol were added. Esterification was carried out at 230℃ and 2.5MPa (gauge pressure). When the water output reached 90% of the theoretical amount, esterification was stopped, the pressure was released to atmospheric pressure, and stirring was continued for 10 minutes. The temperature was gradually increased to enter the low vacuum stage. After heating for 45 minutes, polycondensation was carried out at 280℃ and a vacuum of <100Pa. When the stirring power reached the rated value, the product was discharged to obtain polyester material.

[0107] Example 8

[0108] In a 20L reactor, 2.5kg of terephthalic acid (PAT), 2.5kg of isophthalic acid, 3kg of ethylene glycol, 35g of resorcinol and formaldehyde linear condensate (E), and 3g of antimony glycol were added. Esterification was carried out at a temperature of 220℃ and a pressure (gauge pressure) of 2.6MPa. When the amount of water discharged reached 90% of the theoretical amount, esterification was stopped, the pressure was released to atmospheric pressure, and stirring was continued for 10 minutes. The temperature was gradually increased to enter the low vacuum stage. After the heating time was 45 minutes, polycondensation was carried out at a temperature of 280℃ and a vacuum degree of <100Pa. When the stirring power reached the rated value, the material was discharged to obtain polyester material.

[0109] Example 9

[0110] In a 20L polymerization reactor, 4.38 kg of terephthalic acid, 0.62 kg of isophthalic acid, 4.12 kg of 1,3-propanediol, 558 g of linear condensate of phenol and formaldehyde (A), 3.32 g of antimony glycolate, and 2.12 g of tetrabutyl titanate were added as raw materials and stirred into a uniform slurry. This slurry was then added to a reaction vessel for esterification. The esterification reaction was carried out under pressure in a nitrogen atmosphere, with the pressure controlled at 0.18 MPa and the temperature controlled at 250℃. The esterification reaction was considered to have ended when the amount of water distilled out reached more than 90% of the theoretical value. After the esterification reaction was completed, the temperature was gradually increased to enter a low vacuum stage. After about 45 minutes of low vacuum, the high vacuum polycondensation stage was entered (vacuum pressure less than 100 Pa) at a polycondensation temperature of 255℃. The material was discharged when the stirring current of the reaction vessel reached the set value, thus obtaining the polyester material.

[0111] Example 10

[0112] 100g of terephthalic acid, 250g of isophthalic acid, 28g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0113] Example 11

[0114] 210g of terephthalic acid, 140g of isophthalic acid, 20g of linear condensate of phenol and formaldehyde (C), 360g of 1,4-butanediol, and 0.17g of tetraethyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 180℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 245℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0115] Example 12

[0116] 175g of terephthalic acid, 175g of isophthalic acid, 24g of linear condensate of phenol and formaldehyde (D), 360g of 1,4-butanediol, and 0.35g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 230℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 265℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0117] Comparative Example 1

[0118] 350g of terephthalic acid, 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After purging with nitrogen three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0119] Comparative Example 2

[0120] 315g of terephthalic acid, 35g of isophthalic acid, 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After purging with nitrogen three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45 minutes. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0121] Comparative Example 3

[0122] PBT was prepared according to the method described in Comparative Example 2, and the obtained PBT was mixed with 4.7g of a linear condensate of phenol and formaldehyde (A) to obtain a mixed polyester material.

[0123] Comparative Example 4

[0124] 350g of terephthalic acid, 20g of linear condensate of phenol and formaldehyde (A), 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0125] Comparative Example 5

[0126] 210g of terephthalic acid, 140g of isophthalic acid, 360g of 1,4-butanediol and 0.3g of tetraethyl titanate catalyst were added to a 2L reactor and mixed evenly. After nitrogen purging three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45min. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0127] Comparative Example 6

[0128] 175g of terephthalic acid, 175g of isophthalic acid, 360g of 1,4-butanediol, and 0.3g of tetrabutyl titanate catalyst were added to a 2L reactor and mixed thoroughly. After purging with nitrogen three times, the mixture was heated to 210℃. When the esterification water content reached 90% of the theoretical amount, the temperature was gradually increased and the mixture was transferred to a low vacuum stage. The heating time was 45 minutes. Then, the reaction was carried out at a temperature of 255℃ and a vacuum degree of <100Pa. The product was discharged when the stirring power reached the rated value to obtain polyester material.

[0129] Comparative Example 7

[0130] Add 2.5 kg of terephthalic acid (PAT), 2.5 kg of isophthalic acid, 3 kg of ethylene glycol, and 3 g of antimony glycol to a 20 L reactor. Esterification is carried out at a temperature of 220 °C and a pressure (gauge pressure) of 2.6 MPa. When the water output reaches 90% of the theoretical value, esterification is stopped, the pressure is released to atmospheric pressure, and stirring is continued for 10 min. The temperature is gradually increased to enter the low vacuum stage. After about 45 min of low vacuum, the high vacuum polycondensation stage (pressure < 100 Pa) is entered. Polycondensation is carried out at a temperature of 280 °C. When the stirring power reaches the rated value, the material is discharged to obtain polyester material.

[0131] Comparative Example 8

[0132] 5 kg of terephthalic acid, 4.12 kg of 1,3-propanediol, 558 g of linear condensate of phenol and formaldehyde (A), 3.32 g of antimony glycolate, and 2.12 g of tetrabutyl titanate were added to a 20 L polymerization reactor and stirred into a uniform slurry. The slurry was then added to a reaction vessel for esterification. The esterification reaction was carried out under pressure in a nitrogen atmosphere, with the pressure controlled at 0.18 MPa and the temperature controlled at 250 °C. The esterification reaction was considered to have ended when the amount of water distilled out reached more than 90% of the theoretical value. After the esterification reaction was completed, the temperature was gradually increased to enter a low vacuum stage. After about 45 minutes of low vacuum, the high vacuum polycondensation stage was entered (vacuum pressure less than 100 Pa) and the polycondensation temperature was 255 °C. The material was discharged when the stirring current of the reaction vessel reached the set value, and the polyester material was obtained.

[0133] Test case

[0134] The physicochemical properties of the polyesters prepared in the above examples and comparative examples were tested, and the data are shown in Table 1:

[0135] Table 1

[0136]

[0137]

[0138] As can be seen from the results in Table 1, compared with the comparative example, the polyester provided in the embodiment reduces the melting point and increases the glass transition temperature through the interaction between the two structural units. This shows that the technical solution within the scope of protection of the present invention can reduce the melting point while increasing the glass transition temperature, thereby reducing the possibility of nozzle clogging during the spinning process or the meltblown nonwoven fabric preparation process, and facilitating its subsequent application in spinning or the meltblown nonwoven fabric preparation process.

[0139] Test Example 2

[0140] After drying the above polyester material (to a moisture content below 100 ppm), it was melt-plasticized and spun into nonwoven fabric using a screw extruder with a spinneret diameter of 0.25 μm. The properties of the obtained nonwoven fabric and the nozzle details during the preparation process are shown in Table 2.

[0141] Table 2

[0142]

[0143] The above demonstrates that when the polyester provided by this invention is used to prepare nonwoven fabrics, the nozzle cleaning cycle is significantly improved, indicating that the polyester provided by this invention can reduce the possibility of nozzle clogging, and the nonwoven fabric prepared by this polyester has virtually no impact on its strength and air permeability.

[0144] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A polyester material, characterized in that, The polyester material is a polymer containing structural unit A as shown in formula (I) and structural unit B as shown in formula (II); Equation (I); Formula (II); Wherein, R1, R2, and R3 are each independently hydrogen, hydroxyl, or C1-C6 alkyl, R4 is C1-C6 alkyl or hydrogen, R6, R7, R8, and R9 are each independently hydrogen or C1-C6 alkyl, n is a positive integer from 3 to 20, and in the polymer, the weight percentage of structural unit A is 1-8.5%; The polymer also contains structural unit C as shown in formula (III) and structural unit D as shown in formula (IV); Formula (III); Formula (IV); Among them, R 10 R 11 R 12 and R 13 Each is independently C1-C6 alkyl or hydrogen, and R5 is C2-C10 alkylene; in the polymer, the molar amount of the structural unit B accounts for 10-75% of the total molar amount of the structural unit B and the structural unit C.

2. The polyester material according to claim 1, characterized in that, R1 is hydrogen or hydroxyl, R2 and R3 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer from 3 to 15.

3. The polyester material according to claim 2, characterized in that, R2, R3, R4, R6, R7, R8 and R9 are each independently hydrogen or methyl, and n is a positive integer from 3 to 10.

4. The polyester material according to claim 3, characterized in that, R2, R3, R4, R6, R7, R8 and R9 are hydrogen.

5. The polyester material according to claim 1, characterized in that, The R 10 R 11 R 12 and R 13 Each is independently methyl or hydrogen, and R5 is a C2-C6 alkylene group.

6. The polyester material according to claim 5, characterized in that, The R 10 R 11 R 12 and R 13 The R5 is hydrogen, and it is a C2-C4 alkylene group.

7. The polyester material according to any one of claims 1 to 4, characterized in that, The polyester material has a melting point of less than or equal to 215°C and a glass transition temperature of greater than 34°C.

8. The polyester material according to claim 7, characterized in that, The polyester material has a melting point of less than or equal to 190°C and a glass transition temperature of 36-80°C.

9. A method for preparing a polyester material as described in any one of claims 1 to 8, characterized in that, Includes the following steps: (1) Under esterification reaction conditions, diol monomers, diacid monomers, modified monomers and catalysts are mixed to carry out the first stage reaction to obtain prepolymers; The modified monomers include diols containing the structure shown in formula (I) and dicarboxylic acids containing the structure shown in formula (II); Equation (I); Formula (II); Wherein, R1, R2 and R3 are each independently hydrogen, hydroxyl or C1-C6 alkyl, R4 is C1-C6 alkyl or hydrogen, R6, R7, R8 and R9 are each independently hydrogen or C1-C6 alkyl, and n is a positive integer from 3 to 20; (2) Under polycondensation reaction conditions, the prepolymer is subjected to a second stage reaction.

10. The preparation method according to claim 9, characterized in that, In step (1), the weight ratio of the diol containing the structure shown in formula (I) to the diacid containing the structure shown in formula (II) is 1:1-80.

11. The preparation method according to claim 9 or 10, characterized in that, The dicarboxylic acid monomer is a dicarboxylic acid containing the structure shown in formula (III), and the diol monomer is a diol containing the structure shown in formula (IV). Formula (III); Formula (IV); Among them, R 10 R 11 R 12 and R 13 Each is independently a C1-C6 alkyl or hydrogen, and R5 is a C2-C10 alkylene.

12. The preparation method according to claim 9 or 10, characterized in that, In step (1), relative to 100g of dicarboxylic acid monomer, the amount of diol monomer added is 80-260g, the amount of modified monomer added is 10-280g, and the amount of catalyst added is 0.03-0.3g.

13. The preparation method according to claim 12, characterized in that, The catalyst is a titanate catalyst and / or an antimony-containing catalyst.

14. The preparation method according to claim 13, characterized in that, The titanate catalyst is tetrabutyl titanate and / or tetraethyl titanate, and the antimony-containing catalyst is selected from at least one of antimony glycolate, antimony acetate, and antimony trioxide.

15. The preparation method according to claim 9 or 10, characterized in that, In step (1), the esterification reaction conditions include at least the following: a temperature of 180℃-260℃; In step (2), the polycondensation reaction conditions include at least the following: a temperature of 245-290°C and an absolute vacuum of less than 100 Pa.

16. The use of the polyester material according to any one of claims 1-8 or the polyester material prepared by the method according to any one of claims 9-15 in spinning.

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