Polyester manufacturing method

Abstract

A method for producing polyester is provided. [Solution] A method for producing polyester comprises providing a first recycled material, a second recycled material, ethylene glycol, and a phosphorus-containing monomer, wherein the first recycled material comprises polyethylene terephthalate, and the second recycled material comprises bis-2-hydroxyethyl terephthalate, polyethylene terephthalate dimer, polyethylene terephthalate trimer, mono(2-hydroxyethyl)terephthalic acid, or a combination thereof; performing a depolymerization and monomer bonding step using the first recycled material, the second recycled material, ethylene glycol, and the phosphorus-containing monomer to obtain a polyethylene terephthalate oligomer containing a phosphorus monomer; providing a catalyst; and performing a copolymerization step using the polyethylene terephthalate oligomer containing a phosphorus monomer.

Description

Technical Field

[0001] The present invention relates to a method for producing a flame-retardant polyester.

Background Art

[0002] Products such as 3C transmission lines often use fabrics spun from materials such as flame-retardant polyesters. However, products manufactured by the current polyester production method have many problems, which may reduce the competitiveness of the products. Therefore, how to improve the polyester production method is a challenge.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Products such as 3C transmission lines often use fabrics spun from materials such as flame-retardant polyesters. However, products manufactured by the current polyester production method have many problems, which may reduce the competitiveness of the products.

Means for Solving the Problems

[0004] The present invention provides a method for producing a polyester having good product competitiveness.

[0005] The present invention provides a method for producing polyester, comprising: providing a first recycled material, a second recycled material, ethylene glycol, and a phosphorus-containing monomer, wherein the first recycled material comprises polyethylene terephthalate, and the second recycled material comprises bis-2-hydroxyethyl terephthalate, polyethylene terephthalate dimer, polyethylene terephthalate trimer, mono(2-hydroxyethyl)terephthalic acid, or a combination thereof; performing a depolymerization and monomer bonding step using the first recycled material, the second recycled material, the ethylene glycol, and the phosphorus-containing monomer to obtain a polyethylene terephthalate oligomer containing a phosphorus monomer; providing a catalyst; and performing a copolymerization step using the polyethylene terephthalate oligomer containing the phosphorus monomer.

[0006] In one embodiment of the present invention, the phosphorus-containing monomer described above is one of the following: [ka]

[0007] In one embodiment of the present invention, the operating temperature for the depolymerization and monomer bonding steps described above is between 190°C and 230°C, and the operating temperature for the copolymerization step is between 230°C and 280°C.

[0008] In one embodiment of the present invention, the operation time for the depolymerization and monomer bonding steps described above is between 1 and 4 hours, and the operation time for the copolymerization step is between 1 and 5 hours.

[0009] In one embodiment of the present invention, the operating pressure for the copolymerization step described above is between 0.2 Torre and 2 Torre.

[0010] In one embodiment of the present invention, the weight ratio of the second recycled material to the first recycled material described above is between 0.05 and 0.34.

[0011] In one embodiment of the present invention, the weight ratio of ethylene glycol to the first recycled material used is between 0.20 and 0.40.

[0012] In one embodiment of the present invention, the ratio of the phosphorus weight of the phosphorus-containing monomer described above to the total weight of the first recycled material, the second recycled material, and the phosphorus-containing monomer is higher than 0.0065.

[0013] In one embodiment of the present invention, the catalyst described above includes an organometallic, an ionic liquid, or a combination thereof.

[0014] In one embodiment of the present invention, the organometallic compounds described above include organozinc (e.g., zinc acetate), organocobalto (e.g., cobalt acetate), organotitanium (e.g., titanium alkoxide), organotimony (e.g., antimony acetate, antimony glycol), organoaluminum (e.g., organoaluminum acids such as aluminum formate, aluminum acetate, aluminum propionate, etc.), chelate-type titanium catalysts, or other suitable catalysts, of which one type of catalyst may be used alone or in combination, and the ionic liquid includes imidazolium-based ionic liquids (e.g., 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium acetate). [Effects of the Invention]

[0015] Based on the above, the present invention, by designing steps such as depolymerizing multiple types of recycled materials and bonding them with phosphorus-containing monomers to form a polyethylene terephthalate oligomer containing phosphorus monomers, and then copolymerizing it with a catalyst, can simultaneously improve problems that arise from current methods such as physical mixing and chemical modification, such as poor processability, poor flame retardancy, excessively long thermal history and carbon footprint, poor color, and unfriendly environment. In this way, it is possible to produce high-quality flame-retardant polyester with good product competitiveness.

[0016] For a clearer understanding of the above-mentioned features and advantages of the present invention, embodiments are described below in detail in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0017] [Figure 1] This is a partial flow diagram of a method for producing polyester according to one embodiment of the present invention. [Modes for carrying out the invention]

[0018] In the following detailed description, exemplary embodiments disclosing specific details are described for illustrative purposes rather than limiting purposes, thereby providing a complete understanding of each principle of the present invention. However, it will be obvious to those skilled in the art that the present invention may be carried out in other embodiments departing from the specific details disclosed herein. Furthermore, descriptions of well-known apparatus, methods, and materials may be omitted in order to avoid ambiguity in the explanation of each principle of the present invention.

[0019] The present invention will be described in more detail below with reference to the drawings of this embodiment. However, the present invention can be embodied in various forms and should not be limited to the embodiments described herein.

[0020] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same implications as those generally understood by those skilled in the art.

[0021] The term “between” as used herein to define a numerical range is intended to cover values ​​equal to a described endpoint value and the range between such endpoint and the given endpoint. For example, if the size range is between a first number and a second number, then the size range covers the first number, the second number, and any number between the first number and the second number.

[0022] Figure 1 is a partial flow diagram of a method for producing polyester according to one embodiment of the present invention. Referring to Figure 1, the method for producing polyester according to this embodiment includes at least the following steps.

[0023] First, provide a first recycled material, a second recycled material, ethylene glycol, and a phosphorus-containing monomer, wherein the first recycled material contains polyethylene terephthalate (PET), and the second recycled material contains bis-2-hydroxyethyl terephthalate (BHET), polyethylene terephthalate dimer, polyethylene terephthalate trimer, mono(2-hydroxyethyl) terephthalic acid, or a combination thereof, or other suitable polyethylene terephthalate oligomers, preferably bis-2-hydroxyethyl terephthalate. Then, as shown in step S110, perform a depolymerization and monomer bonding step using the aforementioned first recycled material, second recycled material, ethylene glycol, and phosphorus-containing monomer to obtain a polyethylene terephthalate oligomer containing a phosphorus monomer. Here, the definition of an oligomer is a PET polymer with a degree of polymerization of about 3 to 5.

[0024] Subsequently, as shown in step S120, perform a copolymerization step using a polyethylene terephthalate oligomer containing a phosphorus monomer and a catalyst. Among them, the intrinsic viscosity (IV) of the flame-retardant polyester formed in this step may be higher than 0.52 (dl / g), the hue L may be higher than 75%, a may be between ±3, b may be between ±6, and the average yarn breakage rate of the subsequent product is 4 times / day or less, the spinning yield is 80% or more, and the flame retardancy may be at the M1 level. Based on this, this embodiment designs steps such as depolymerizing a plurality of recycled materials, bonding them with a phosphorus-containing monomer to form a phosphorus-containing monomer-containing polyethylene terephthalate oligomer, and then copolymerizing with a catalyst, so as to simultaneously improve problems such as poor processability, poor flame retardancy, excessive thermal history and carbon footprint, poor hue, and not environmentally friendly caused by current methods such as physical mixing and chemical modification. In this way, a high-quality flame-retardant polyester with good product competitiveness can be produced.

[0025] Furthermore, flame-retardant polyesters formed by current physical mixing methods are formed by co-extrusion using an extruder, cooling, and granulation. This results in a tendency for the yarn to break during the subsequent spinning process, leading to poor processability. Additionally, poor mixing uniformity results in inferior flame retardancy. Moreover, current chemical modification methods use terephthalic acid (PTA), ethylene glycol, and phosphorus-containing monomers to directly esterify and copolymerize flame-retardant polyesters. This process often involves prolonged periods of high temperatures, leading to problems such as excessively long thermal histories and poor coloration. Furthermore, it results in an excessively long carbon footprint and generates a significant amount of waste during the manufacturing process, failing to meet environmental protection requirements. Based on this, the manufacturing method of this embodiment does not employ the physical mechanism of extrusion molding or the chemical mechanism of raw materials such as terephthalic acid. Therefore, the co-oligomer structure formed by the manufacturing method of this embodiment can improve upon the problems arising from these current mechanisms. However, the present invention is not limited thereto.

[0026] The following describes the specific operations of each of the steps described above in detail, but these descriptions are not intended to limit the present invention.

[0027] <Depolymerization and phosphorus-containing monomer bonding step>

[0028] In some embodiments, more favorable improvements can be obtained by performing the process under preferred operating conditions. For example, the operating temperature for the depolymerization and phosphorus-containing monomer bonding steps may be between 190°C and 230°C, and / or the operating time for the depolymerization and phosphorus-containing monomer bonding steps may be between 1 hour and 4 hours. More preferred operating conditions include an operating temperature between 200°C and 220°C, and / or an operating time between 1 hour and 3 hours. However, the present invention is not limited thereto.

[0029] In some embodiments, the weight ratio of the second recycled material to the first recycled material used in the depolymerization and phosphorus monomer bonding steps is between 0.05 and 0.34, preferably between 0.1 and 0.2, but the present invention is not limited thereto. Here, the weight ratio of the second recycled material to the first recycled material is obtained by dividing the weight of the second recycled material used by the weight of the first recycled material used. That is, the weight of the second recycled material used may be less than the weight of the first recycled material used.

[0030] In some embodiments, the weight ratio of ethylene glycol to the first recycled material is between 0.20% and 0.40%, but the present invention is not limited thereto. Here, the weight ratio of ethylene glycol to the first recycled material is obtained by dividing the weight of ethylene glycol used by the weight of the first recycled material used. That is, the weight of ethylene glycol used may be less than the weight of the first recycled material used.

[0031] In some embodiments, the source of the first recycled material may be recycled film, recycled PET bottles, recycled fibers, or the like, and the recycling method for the second recycled material may be, for example, performing an appropriate ethylene glycol glycolysis and purification process on waste PET polyester, but the present invention is not limited thereto. The first and second recycled materials may be manufactured using any suitable source and recycling method well known to those skilled in the art.

[0032] In some embodiments, the hue L of the first recycled material may be higher than 58%, a may be between ±1, and b may be between ±1. Similarly, the hue L of the second recycled material may be higher than 90%, a may be between ±1, and b may be between ±1, but the present invention is not limited thereto.

[0033] In some embodiments, the ratio of the phosphorus weight of the phosphorus-containing monomer to the total weight of the first recycled material, the second recycled material, and the phosphorus-containing monomer is higher than 0.0065, but the present invention is not limited thereto. Here, the ratio of the phosphorus weight of the phosphorus-containing monomer to the total weight of the first recycled material, the second recycled material, and the phosphorus-containing monomer is obtained by dividing the phosphorus weight of the phosphorus-containing monomer by the total weight of the first recycled material, the second recycled material, and the phosphorus-containing monomer.

[0034] In some embodiments, the phosphorus-containing monomer exhibits more preferable reactivity if it is any of the following, but the present invention is not limited thereto: [ka] (CAS No: 14657-64-8) JPEG2026111460000004.jpg3759(CAS No:63562-34-5), JPEG2026111460000005.jpg2035(Clariant Exolit PE100), JPEG2026111460000006.jpg2552 (Opened ring format of Clariant Exolit PE100), JPEG2026111460000007.jpg2532(CAS No:63562-33-4).

[0035] <Copolymerization step>

[0036] In some embodiments, more favorable improvements can be obtained by performing the process under preferred operating conditions. For example, the operating temperature of the copolymerization step may be between 230°C and 280°C, and / or the operating time of the copolymerization step may be between 1 hour and 5 hours. More preferred operating conditions include an operating temperature between 240°C and 270°C, and / or an operating time between 2 hours and 4 hours, but the present invention is not limited thereto.

[0037] In some embodiments, the copolymerization pressure may be controlled between 0.2 Torre and 2 Torre, preferably between 0.5 Torre and 1.5 Torre, but the present invention is not limited thereto.

[0038] In some embodiments, the catalyst comprises organometallic compounds, ionic liquids, or combinations thereof. For example, organometallic compounds include organozinc (e.g., zinc acetate), organocobalt (e.g., cobalt acetate), organotitanium (e.g., titanium alkoxide), organotimony (e.g., antimony acetate, antimony glycol), organoaluminum (e.g., aluminum formate, aluminum acetate, propylenealuminate, etc.), chelate-type titanium catalysts, or other suitable catalysts. The catalyst may be used alone or in combination of multiple types. The ionic liquid includes, but is not limited to, imidazolium ionic liquids (e.g., 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium acetate). The catalyst may further include titanium dioxide.

[0039] The effects of the present invention will be explained below with reference to examples and comparative examples, but the scope of the present invention is not limited to the scope of the examples.

[0040] The polyesters produced in each example and comparative example were evaluated based on the following method.

[0041] Intrinsic viscosity (IV): ASTM D4603 measurement method.

[0042] Phosphorus content: Ester particle samples were quantified by measuring their absorbance using a UV-Vis spectrometer after pretreatment.

[0043] Hue: The color space defined by the CIE Lab (International Commission on Illumination) is adopted. The color space (Lab color space) is a relative color space, with dimension L representing lightness (whiteness of color) and a and b representing relative color dimensions, and is based on a non-linear compression of the coordinates of the CIE XYZ color space.

[0044] Yield: Amount of eligible polyester actually obtained / Amount of primary recycled material (PET) raw material used × 100%.

[0045] Average yarn breakage rate: Total number of yarn breaks / Production time (days)

[0046] Flame retardancy: NF P 92-507 standard is adopted.

[0047] The polyester of Example 1 was manufactured by the following method.

[0048] In accordance with step S110, a depolymerization and monomer bonding step was performed using 60 kilograms of first recycled material (PET bottle recycled material), 20 kilograms of second recycled material (bis-2-hydroxyethyl terephthalate), 20 kilograms of ethylene glycol, and 3 kilograms of phosphorus-containing monomer (compound 1, CAS NO.: 14657-64-8) to obtain a bis-2-hydroxyethyl terephthalate oligomer. Furthermore, under operating conditions of a reaction vessel heating temperature of 265°C, a pressure of 0.8 bar, and 2 hours, the temperature of the above materials was raised from room temperature to 225°C / 230°C and maintained at that temperature for 0.5 hours. The above reactants were then subjected to a depolymerization and monomer bonding step in the reaction vessel.

[0049] Corresponding to step S120, a copolymerization step was carried out with the obtained bis-2-hydroxyethyl terephthalate oligomer and catalyst (antimony glycol (antimony content: 275 ppm), 0.5 kg of titanium dioxide) to obtain the flame-retardant polyester of Example 1. Furthermore, a preliminary polymerization reaction was carried out for 60 minutes at a reaction vessel heating temperature of 275°C and a reaction pressure that was reduced from atmospheric pressure to 20 Tor over 1 hour. Subsequently, the copolymerization step was carried out under conditions of a reaction temperature of 265°C and a reaction pressure of <1.0 Tor for 120 minutes.

[0050] Polyester of Example 2 and Comparative Example 1

[0051] The manufacturing method is the same as that of Example 1 described above, with the only difference being the slightly different amounts of the first recycled material, the second recycled material, and ethylene glycol used. Please refer to Table 1 for the amounts used.

[0052] [Table 1]

[0053] The properties and spinning evaluation of the polyesters in Examples 1 and 2 and Comparative Example 1 are shown in Table 2.

[0054] [Table 2]

[0055] In summary, the present invention, by designing steps such as depolymerizing multiple types of recycled materials and bonding them with phosphorus-containing monomers to form phosphorus monomer-containing polyethylene terephthalate oligomers, and then copolymerizing them with a catalyst, can simultaneously improve problems that arise from current methods such as physical mixing and chemical modification, including poor processability, poor flame retardancy, excessively long thermal history and carbon footprint, poor color, and environmental friendliness. In this way, it is possible to produce high-quality flame-retardant polyester with good product competitiveness.

[0056] Although the present invention has been disclosed above by embodiments, this is not intended to limit the invention, and those skilled in the art may make some modifications and changes without departing from the spirit of the invention, and therefore the scope of protection of the present invention shall be determined by the appended claims. [Industrial applicability]

[0057] The method for manufacturing polyester can be applied to the field of flame-retardant polyesters. [Explanation of Symbols]

[0058] S110, S120: Step

Claims

1. The present invention provides a first recycled material, a second recycled material, ethylene glycol, and a phosphorus-containing monomer, wherein the first recycled material comprises polyethylene terephthalate, and the second recycled material comprises bis-2-hydroxyethyl terephthalate, polyethylene terephthalate dimer, polyethylene terephthalate trimer, mono(2-hydroxyethyl) terephthalic acid, or a combination thereof. By performing depolymerization and monomer bonding steps on the first recycled material, the second recycled material, the ethylene glycol, and the phosphorus-containing monomer, a polyethylene terephthalate oligomer containing a phosphorus monomer is obtained. To provide a catalyst, The copolymerization step is carried out using the polyethylene terephthalate oligomer containing the phosphorus monomer and the catalyst. including, A method for manufacturing polyester.

2. The phosphorus-containing monomer is one of the following: Method for producing polyester according to claim 1: 【Transformation 3】

3. The operating temperature for the depolymerization and monomer bonding steps is between 190°C and 230°C, and the operating temperature for the copolymerization step is between 230°C and 280°C. A method for producing polyester according to claim 1.

4. The operation time for the depolymerization and monomer bonding steps is between 1 and 4 hours, and the operation time for the copolymerization step is between 1 and 5 hours. A method for producing polyester according to claim 1.

5. The operating pressure for the copolymerization step is between 0.2 Torre and 2 Torre. A method for producing polyester according to claim 1.

6. The weight ratio of the second recycled material to the first recycled material is between 0.05 and 0.

34. A method for producing polyester according to claim 1.

7. The weight ratio of ethylene glycol to the first recycled material is between 0.2 and 0.

4. A method for producing polyester according to claim 1.

8. The ratio of the phosphorus weight of the phosphorus-containing monomer to the total weight of the first recycled material, the second recycled material, and the phosphorus-containing monomer is higher than 0.0065. A method for producing polyester according to claim 1.

9. The catalyst includes organometallic, ionic liquid, or a combination thereof. A method for producing polyester according to claim 1.

10. The organometallic includes zinc acetate, organotitanium, organotimon, organoaluminum, or a combination thereof, and the ionic liquid includes an imidazolium-based ionic liquid. The method for producing polyester according to claim 9.

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