2,5-Franzylcarboxylic acid particles, their manufacturing method, and use

Abstract

This invention discloses 2,5-franzicarboxylic acid particles, their manufacturing method, and use, and belongs to the technical field of polymerization reaction bio-based monomer production. FDCA particles obtained by heating, dissolving, cooling, filtering, and drying 2,5-franzicarboxylic acid in water at high temperature have almost no corners, the particle surface is round and smooth, the sphericity is high, the fluidity is good, the average particle size is 50-200 μm, the loose bulk density is 0.7-1.0 g / mL, and the angle of repose is 25-40°. This invention improves the fluidity of FDCA slurry by changing the microscopic morphology and particle size distribution of FDCA solid particles, which is advantageous for material uniformity in the polymerization process, shortens the polymerization reaction time, reduces the amount of ethylene glycol used, and is advantageous for reducing the content of diethylene glycol, an impurity.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing polymerizable reaction bio-based monomers, and specifically relates to 2,5-furandicarboxylic acid particles, a method for manufacturing the same, and uses thereof.

Background Art

[0002] 2,5-Furandicarboxylic acid (FDCA) can be produced from biomass raw materials. In a general production process, biomass containing hexose is dehydrated to produce 5-hydroxymethylfurfural (5-HMF), and then 5-HMF is oxidized to produce FDCA. FDCA can be used as an alternative to terephthalic acid (PTA), a petroleum-based monomer, to produce high-performance polymers, such as polyethylene-2,5-furandicarboxylate (PEF). This polymer has better oxygen and carbon dioxide barrier properties and a lower carbon footprint compared to polyethylene terephthalate (PET), and thus has attracted wide attention. Due to its biomass origin, the use of PEF plastics can reduce dependence on petroleum-based polymers.

[0003] Currently, the technologies for oxidizing paraxylene (PX) to produce PTA and polymerizing PTA and ethylene glycol to produce PET are already very mature. The global production capacity of PTA exceeds 95 million tons, and the production capacity of bottle-grade PET exceeds 35 million tons. Usually, in the polymerization reaction process for producing PET, after terephthalic acid and ethylene glycol are mixed, they are introduced into the reaction system in the form of a slurry. In this process, it is desirable that the slurry fluidity of terephthalic acid is good in order to improve the uniformity of the reaction. Moreover, good powder fluidity is also advantageous for powder treatment processes such as the transportation and storage of terephthalic acid. Industrially, in order to obtain good slurry properties and reaction uniformity, it can be adjusted by using a stoichiometric excess of ethylene glycol with respect to terephthalic acid. However, excess ethylene glycol may cause an increase in impurities and energy consumption in the polycondensation reaction.

[0004] FDCA, as a substitute for PTA, similarly requires a similar polymerization process. The slurry formed by mixing FDCA particles with ethylene glycol needs to have good fluidity, which improves reaction uniformity and shortens polymerization reaction time. Patent document CN114929679A discloses a method for producing a carboxylic acid composition containing 2,5-franzicarboxylic acid, in which the heat treatment is carried out such that a certain percentage of FDCA dissolves in the treatment solvent composition during the heat treatment, while residual FDCA remains as a solid precipitate. The chemical equilibrium and exchange between the dissolved and precipitated FDCA during the heat treatment results in a specific favorable particle shape, increased particle strength, and / or a beneficial particle size distribution of FDCA, but there is a problem of low yield of FDCA particles because the chemical equilibrium and exchange between the dissolved and precipitated FDCA are difficult to control. Patent document CN116120264A discloses a method for adjusting the particle size of 2,5-franzicarboxylic acid crystals, which involves adding a crystallization aid to the FDCA raw material, adjusting the type and content of the aid, and adjusting process parameters such as the crystallization temperature to obtain FDCA crystals within a certain particle size range, and the average particle size d of the FDCA crystals 50 The particle size is 20-2000 μm, but this method requires the use of a adjusting agent, which reduces crystal purity and makes the method more complex.

[0005] The slurry fluidity of FDCA is affected by the particle size distribution and average particle size of the FDCA particles. Generally, a wide particle size distribution range from large to small particles tends to improve the slurry properties of the particles. The average particle size is usually preferably in the range of 50 to 150 μm. If the proportion of particles with a particle size of 250 μm (40 mesh) or larger increases, FDCA becomes less likely to react completely when polymerized by the direct method, leading to problems such as prolonged reaction time and an increase in by-products.

[0006] To achieve good slurry properties and reaction uniformity, as in the direct polymerization method of PET, stoichiometrically excess ethylene glycol can be used relative to FDCA. However, excess ethylene glycol leads to problems such as an increase in diethylene glycol fragments (an impurity), a decrease in the degree of polymerization, and darkening of the color. However, as the amount of ethylene glycol used approaches the stoichiometric ratio of FDCA, the polymerization reaction system becomes very viscous, solid particles are unevenly dispersed, and the power consumption required for stirring increases.

[0007] Therefore, in order to improve the slurry properties in the polymerization reaction process, there is an urgent need for 2,5-franzicarboxylic acid particles and a method for producing them that can solve the above problems. [Overview of the project] [Problems that the invention aims to solve]

[0008] The first object of the present invention is to provide 2,5-flangecarboxylic acid particles that solve the problem of the non-uniform distribution and poor discreteness of conventional FDCA particles. A second object of the present invention is to provide a method for producing 2,5-flangecarboxylic acid particles. A third object of the present invention is to provide the use of 2,5-flangecarboxylic acid particles in the polyethylene-2,5-flangecarboxylate (FEF) synthesis process in order to solve the problems in conventional FEF production processes, which include low polymerization reaction efficiency due to poor fluidity and poor uniformity of the mixed slurry of FDCA and ethylene glycol, and a high content of diethylene glycol as an impurity. [Means for solving the problem]

[0009] The object of the present invention can be achieved by the following technical means.

[0010] In the first embodiment, 2,5-flangecarboxylic acid particles are characterized by having an average particle size of 50 to 200 μm, a loose bulk density of 0.7 to 1.0 g / mL, and an angle of repose of 25 to 40°.

[0011] In the second embodiment, the method for producing 2,5-franzicarboxylic acid particles is: The process includes the steps of: placing 2,5-franzicarboxylic acid raw materials in an autoclave; adding deionized water to the autoclave to obtain a mixture; starting stirring and heating; raising the system temperature (25-30°C) from room temperature to 100-150°C; maintaining the temperature to allow the reaction to proceed; cooling to room temperature after the heating is complete; and filtering and recovering the material, washing it to obtain moist 2,5-franzicarboxylic acid, and drying it to obtain 2,5-franzicarboxylic acid particles.

[0012] As a further technical means of the present invention, the purity of the 2,5-franzicarboxylic acid raw material is >95%.

[0013] As a further technical means of the present invention, the pressure of the system inside the autoclave is <1.5 MPa.

[0014] As a further technical means of the present invention, the mass percentage of 2,5-franzicarboxylic acid in the mixture is 5% to 20%.

[0015] As a further technical means of the present invention, the stirring speed is 200 to 400 rpm.

[0016] As a further technical means of the present invention, the heating time is 2 to 4 hours.

[0017] As a further technical means of the present invention, the heat retention time is 0.5 to 6 hours.

[0018] As a further technical means of the present invention, the cooling time is 2 to 10 hours.

[0019] In a third aspect, the 2,5-flangecarboxylic acid particles or 2,5-flangecarboxylic acid particles produced by the above-described method for producing 2,5-flangecarboxylic acid particles are used in a polymerization reaction. [Effects of the Invention]

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows.

[0021] 1. The 2,5-furandicarboxylic acid disclosed in the present invention has a simple manufacturing method. The FDCA particles produced by its manufacturing method are almost angular in microscopic morphology, with a round and smooth particle surface, high sphericity, good dispersibility, high bulk density, an average particle size of 50 - 200 μm, a loose bulk density of 0.7 - 1.0 g / mL, and an angle of repose (also called the angle of rest) of 25 - 40°.

[0022] 2. According to the present invention, by changing the appearance shape and particle size distribution of the FDCA solid particles, the fluidity of the FDCA slurry can be significantly improved, which is beneficial to improving the uniformity of the materials in the polymerization reaction and shortening the polymerization reaction time. It can reduce the equivalent amount of ethylene glycol used in the polymerization process of PEF and is beneficial to reducing the content of diethylene glycol, an impurity.

Brief Description of the Drawings

[0023] The present invention will be further described below with reference to the drawings. [Figure 1] It is a microscopic morphology diagram of the FDCA particles produced in Example 1 of the present invention. [Figure 2] It is a microscopic morphology diagram of the FDCA raw material in the present invention.

Modes for Carrying Out the Invention

[0024] Hereinafter, the embodiments of the present invention will be combined to clearly and completely explain the technical means in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative labor are included in the protection scope of the present invention.

[0025] A method for producing 2,5-franzicarboxylic acid particles includes the following steps:

[0026] A starting material of 2,5-franján carboxylic acid with a purity of >95% is placed in an autoclave, deionized water is added to the autoclave to obtain a mixture, the mass percentage of 2,5-franján carboxylic acid in the mixture is 5% to 20%, stirring and heating are started at a stirring speed of 200 to 400 rpm, the temperature of the system is raised from room temperature to 100 to 150°C for 2 to 4 hours, and the reaction is carried out while maintaining the temperature for 0.5 to 6 hours, the pressure of the system in the autoclave during the reaction process is <1.5 MPa, after the heating is completed, it is cooled to room temperature for 2 to 10 hours, the material is filtered and recovered, washed to obtain moist 2,5-franján carboxylic acid, and dried to obtain 2,5-franján carboxylic acid particles.

[0027] Example 1 A method for producing 2,5-franzicarboxylic acid particles includes the following steps:

[0028] 100 g of 2,5-franjic acid starting material with a purity of 99.5% was placed in an autoclave, 400 g of deionized water was added to the autoclave to obtain a mixture, and after sealing, stirring and heating were started at a stirring speed of 300 rpm, raising the system temperature from room temperature to 145°C for 2.5 hours, and the reaction was carried out by maintaining the temperature for 6 hours, with the system pressure inside the autoclave being 1 MPa during the reaction process, and after the heating was completed, it was cooled to room temperature for 4 hours, and the material was filtered and recovered, washed with a small amount of deionized water to obtain moist 2,5-franjic acid, which was then dried to obtain 2,5-franjic acid particles.

[0029] Example 2 A method for producing 2,5-franzicarboxylic acid particles, similar to Example 1, except that 1900 g of deionized water is added to the autoclave, while the remaining components and parameters remain unchanged.

[0030] Example 3 A method for producing 2,5-franzicarboxylic acid particles, similar to Example 1, except that 990 g of deionized water is added to the autoclave, while the remaining components and parameters remain unchanged.

[0031] Example 4 A method for producing 2,5-flange carboxylic acid particles, similar to Example 1, except that the holding time after heating is 1.5 hours, while the remaining components and parameters remain unchanged.

[0032] Example 5 A method for producing 2,5-flange carboxylic acid particles, similar to Example 1, except that the holding time after heating is 5.5 hours, while the remaining components and parameters remain unchanged.

[0033] Example 6 A method for producing 2,5-flangecarboxylic acid particles, similar to Example 1, except that the system temperature is raised from room temperature to 110°C and the heating time is 2 hours, while the remaining components and parameters remain unchanged.

[0034] Example 7 A method for producing 2,5-flangecarboxylic acid particles, similar to Example 1, except that the system temperature is raised from room temperature to 130°C and the heating time is 2 hours, while the remaining components and parameters remain unchanged.

[0035] Example 8 A method for producing 2,5-franzicarboxylic acid particles, similar to Example 1, except that after the heating period is complete, the mixture is cooled to room temperature for 1.5 hours, and the remaining components and parameters remain unchanged.

[0036] Example 9 A method for producing 2,5-franzicarboxylic acid particles, similar to Example 1, except that after the heating period is completed, the mixture is cooled to room temperature and the cooling time is 6 hours, while the remaining components and parameters remain unchanged.

[0037] Example 10 A method for producing 2,5-franzicarboxylic acid particles, similar to Example 1, except that after the heating period is complete, the mixture is cooled to room temperature for 9 hours, and the remaining components and parameters remain unchanged. The 2,5-flange carboxylic acid particles produced in Examples 1 to 10 were evaluated for their performance.

[0038] (1) Microcharacterization of microscopic morphology: Figure 1 is a microscopic morphological diagram of 2,5-franglicarboxylic acid particles produced in Example 1, and Figure 2 is a microscopic morphological diagram of the 2,5-franglicarboxylic acid raw material. As can be seen from the comparison between Figure 1 and Figure 2, the FDCA particles after the reaction have almost no corners in their external morphology, the particle surface is round and smooth, the degree of sphericity is high, and the dispersion is good.

[0039] (2) Average particle size: Calculated after sieving with a standard sieve.

[0040] (3) Bulk density: The bulk density of the particles was measured according to the test method specified in GB / T16913-2008.

[0041] (4) Measurement of angle of repose: The angle of repose of the particles was measured according to the test method specified in GB / T16913-2008. The measurement results are shown in Table 1.

[0042] [Table 1]

[0043] As can be seen from Table 1, the mass fraction of FDCA in the FDCA-water mixture, the heating temperature and holding time, and the cooling time are all factors that affect the average particle size, bulk density, and angle of repose of the FDCA particles. By optimizing the reaction conditions, high-quality FDCA particles can be obtained.

[0044] Example 11 The method for using 2,5-flange carboxylic acid particles, employing the synthesis of polyethylene flanger carboxylate as a model example of a polymerization reaction, includes the following steps.

[0045] 15.6 g, 0.1 mol of 2,5-franj carboxylic acid particles (15.6 g, 0.1 mol) and ethylene glycol (6.8 g, 0.11 mol) produced in Example 1 were added to a slurry tank and thoroughly mixed in the slurry tank. Then, the mixture was placed in an esterification tank and reacted at 190°C for 2 hours, after which the reaction was stopped and the water was discharged. 0.78 g of germanium oxide was added as a catalyst to the dimethyl franj carboxylic acid produced in the esterification step, and melting and polycondensation were carried out in a polycondensation reactor. The reaction was carried out at a pressure of 70 Pa and 235°C for 3 hours, after which the reaction was stopped to obtain the polymer PEF (polyethylene franj carboxylate).

[0046] Comparative Example 1 99.5% pure 2,5-franj carboxylic acid raw material (15.6 g, 0.1 mol) and ethylene glycol (6.8 g, 0.11 mol) were added to a slurry tank and thoroughly mixed in the slurry tank. Then, the mixture was placed in an esterification tank and reacted at 190°C for 2 hours, after which the reaction was stopped and the water was discharged. 0.78 g of germanium oxide was added as a catalyst to the dimethyl franj carboxylic acid produced in the esterification step, and then melting and polycondensation were carried out in a polycondensation reactor. The reaction was carried out at a pressure of 70 Pa and 235°C for 3 hours, after which the reaction was stopped to obtain the polymer PEF (polyethylene franj carboxylate).

[0047] Performance tests were conducted on the PEF polyester produced in Example 11 and Comparative Example 1.

[0048] Measurement of diethylene glycol content: The diethylene glycol content was measured using the methanol transesterification method according to GB / T14190-2017.

[0049] Measurement of PEF polyester molecular weight: The molecular weight of the polyester was measured by gel permeation chromatography (GPC).

[0050] The measurement results are shown in Table 2.

[0051] [Table 2]

[0052] As can be seen from Table 2, when producing PEF under the same parameter usage conditions, the high-quality FDCA particles obtained by optimizing the reaction conditions are advantageous in improving the uniformity of the material during the polymerization process of PEF, as well as shortening the polymerization reaction time. More importantly, it allows for a reduction in the amount of ethylene glycol used, which is advantageous in reducing the content of diethylene glycol, an impurity.

[0053] In this specification, relational terms such as "First" and "Second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply that such an actual relationship or order exists between these entities or operations. Furthermore, the terms "include," "incorporate," or any other variation thereof are intended to cover non-exclusive inclusion, so a process, method, article, or apparatus that includes a set of elements includes not only those elements but also other elements not explicitly listed, or further elements specific to such a process, method, article, or apparatus.

[0054] Although embodiments of the present invention have been described, those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is limited by the appended claims and equivalents.

Claims

1. 2,5-flangecarboxylic acid particles characterized by an average particle size of 50 to 200 μm, a loose bulk density of 0.7 to 1.0 g / mL, and an angle of repose of 25 to 40°.

2. A method for producing 2,5-franzicarboxylic acid particles according to claim 1, comprising the steps of: placing a 2,5-franzicarboxylic acid raw material in an autoclave; adding deionized water to the autoclave to obtain a mixture; starting stirring and heating to raise the temperature of the system from room temperature to 100-150°C, and then maintaining the temperature to allow the reaction to proceed; cooling to room temperature after the maintenance of temperature has finished; and filtering and recovering the material, washing it to obtain moist 2,5-franzicarboxylic acid, and drying it to obtain 2,5-franzicarboxylic acid particles.

3. The method for producing 2,5-franzicarboxylic acid particles according to claim 2, characterized in that the purity of the 2,5-franzicarboxylic acid raw material is >95%.

4. The method for producing 2,5-flange carboxylic acid particles according to claim 2, characterized in that the pressure of the system in the autoclave is <1.5 MPa.

5. The method for producing 2,5-franzicarboxylic acid particles according to claim 2, characterized in that the mass percentage of 2,5-franzicarboxylic acid in the mixture is 5% to 20%.

6. The method for producing 2,5-flange carboxylic acid particles according to claim 2, characterized in that the stirring speed is 200 to 400 rpm.

7. The method for producing 2,5-flangecarboxylic acid particles according to claim 2, characterized in that the heating time is 2 to 4 hours.

8. The method for producing 2,5-franzicarboxylic acid particles according to claim 2, characterized in that the aforementioned heat retention time is 0.5 to 6 hours.

9. The method for producing 2,5-franzicarboxylic acid particles according to claim 2, characterized in that the cooling time is 2 to 10 hours.

10. Use of 2,5-flangecarboxylic acid particles in a polymerization reaction according to claim 1.

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