Copolyester reaction device and production method thereof

Abstract

The invention provides a copolyester reaction device and a production method thereof, and belongs to the technical field of chemical production, the copolyester reaction device comprises a pulping tank a, an esterification reactor a, an esterification reactor b, a prepolymerization kettle a, a prepolymerization kettle b, a polycondensation kettle and granulation equipment, and is also provided with a pulping tank b, an esterification reactor c, an esterification reactor d and a mixer, the specific production method comprises the following steps: adding PTA and ethylene glycol into a pulping tank a, fully mixing, and carrying out esterification reaction to obtain an esterification product A; adding DMT and any one of 1, 4-cyclohexanedimethanol, 2, 2, 4, 4-tetramethyl cyclobutanediol, isosorbide and spiro ethylene glycol into a pulping tank b, fully mixing, and carrying out esterification reaction to obtain an esterification product B; adding the esterification product A and the esterification product B into a mixer, mixing, sequentially adding into a pre-polymerization kettle a, a pre-polymerization kettle b and a polycondensation kettle, and adding a catalyst and a stabilizer into the polycondensation kettle to obtain a copolyester product; adding of a release agent and a flow increasing agent is completed through an auxiliary agent filling system before granulation forming; and carrying out granulation operation through granulation equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production, and particularly relates to a copolyester reaction device and a production method thereof. Background Art

[0002] First, esterification is the reaction between a dibasic acid and a diol to produce an ester and water. Temperature control is critical here because it affects the reaction rate, equilibrium, and the occurrence of side reactions.

[0003] Generally speaking, increasing temperature accelerates the reaction rate because, according to the Arrhenius equation, higher temperature increases the reaction rate constant. However, esterification reactions are reversible, so the effect of temperature on the equilibrium must also be considered. According to Le Chatelier's principle, if the reaction is exothermic, increasing the temperature will be detrimental to product formation. In fact, the ΔH value of esterification reactions is usually positive, indicating that the reaction is endothermic, so increasing the temperature may be beneficial to the yield. However, the actual situation is more complicated because the reactivity of different carboxylic acids and alcohols may vary.

[0004] Excessively high temperatures can lead to side reactions, such as dehydration, decomposition, or intermolecular dehydration to form ethers. For example, if concentrated sulfuric acid is used as a catalyst, excessively high temperatures can lead to carbonization or dehydration of alcohols to form olefins. The appropriate temperature range must be determined based on the specific reactants. For example, ethanol, an alcohol, may produce ethylene at high temperatures, while carboxylic acids such as acetic acid may decompose at high temperatures.

[0005] Furthermore, different catalysts may have different temperature requirements. The boiling points of the reactants must also be considered. If the reaction temperature approaches the boiling point of the reactants or products, this may result in volatilization losses, affecting yield. In this case, a reflux system or a fractionating column may be necessary to remove water and promote the reaction toward the product.

[0006] In the traditional direct esterification method, PTA reacts directly with diols such as ethylene glycol and isosorbide. However, due to the large steric hindrance of isosorbide and the low reaction activity with dicarboxylic acids, it is difficult to directly synthesize high-performance polyesters. The esterification temperature and time need to be increased. Long-term high-temperature heating causes decomposition, branching or cross-linking side reactions, resulting in poor product hue. In addition, the substandard esterification rate seriously interferes with the polycondensation reaction, resulting in low product molecular weight and substandard impact performance of the product.

[0007] Temperature control during the esterification reaction is very important. Excessively high esterification temperature will cause the loss of ethylene glycol and take away a large amount of heat energy. In the actual production process, how to control the esterification temperature is a very difficult thing to control. The applicant has improved the existing process. The existing process is a single reaction and cannot achieve precise temperature control. The double reaction and remixing method can achieve precise temperature control, thereby avoiding the loss of ethylene glycol and taking away a large amount of heat energy due to excessively high esterification temperature.

[0008] Existing mixing equipment requires heating during mixing, usually using external heating and a pipe-in-tube design. This method results in large energy losses. The applicant has made corresponding improvements to the existing mixing equipment, which can meet the requirements of heating the mixing equipment to protect the fluidity of the material while also bringing about better stirring and mixing effects, and can ensure that the material has good fluidity, which is conducive to the subsequent polycondensation reaction. Summary of the Invention

[0009] In order to solve the technical problems raised in the background technology, the present invention provides a method for producing copolyester, and the technical solution adopted is as follows:

[0010] A method for producing copolyester, wherein the method adopts the copolyester reaction device according to any one of claims 1 to 3 to carry out the reaction, characterized in that it comprises the following steps:

[0011] Step 1: PTA and ethylene glycol are added into beating tank a at a molar ratio of 1:1.1-1.4, and after being fully mixed, they are successively fed into esterification reactor a and esterification reactor b to obtain esterification product A;

[0012] Step 2: DMT and any one of 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethylcyclobutanediol, isosorbide, and spiroethylene glycol are added to a beating tank b at a molar ratio of 1:1.1-1.4, and after being fully mixed, they are successively introduced into an esterification reactor c and an esterification reactor d to obtain an esterification product B;

[0013] Step 3: Add esterification product A and esterification product B into a mixer at a molar ratio of 2:3, and fully mix the two esterification products through the mixer;

[0014] Step 4: After mixing, add the mixture to prepolymerization kettle a, prepolymerization kettle b and polycondensation kettle in sequence, and add catalyst and stabilizer to the polycondensation kettle to obtain a copolyester product;

[0015] Step 5: Before granulation and molding, the release agent and flow enhancer are added through the additive injection system;

[0016] Step 6: Perform granulation operation.

[0017] In order to achieve a better mixing effect, the applicant has made corresponding structural modifications to the existing mixer, which can achieve a better mixing effect. The specific structure of the mixer is as follows:

[0018] A mixer, comprising a housing, on which there are a first feed inlet, a second feed inlet and a discharge outlet, and characterized in that steam inlet pipelines and steam outlet pipelines are respectively arranged at both ends of the housing, a cylindrical stirring assembly is arranged inside the housing, the cylindrical stirring assembly is of a hollow structure, stirring blades and stirring rods are arranged on the cylindrical stirring assembly, rotating shafts are arranged at both ends of the cylindrical stirring assembly, the rotating shafts are of a hollow structure, a cylindrical steam heating device is arranged inside the cylindrical stirring assembly, the cylindrical steam heating device is of a hollow structure and is provided with a plurality of jet ports around it, the rotating shafts are communicated with the steam heating device and are respectively connected with the steam inlet pipeline and the steam outlet pipeline through sealing bearings at both ends to form steam heating, and the cylindrical steam heating device is connected with the cylindrical stirring assembly through fixing pieces.

[0019] Preferably: a plurality of circular baffles are arranged on the right side of the cylindrical stirring assembly, and a plurality of circular through holes are arranged on the circular baffles. Such a design can better mix the materials.

[0020] The working principle of the above mixer is as follows: Steam enters the steam heating device through the inlet pipeline. The steam jets outwards from the jet ports to drive the steam heating device to rotate. The steam heating device drives the cylindrical stirring assembly to rotate to accelerate the mixing of the materials, making the material mixing more uniform. The existing mixers are generally heated by an external jacket, which is more likely to cause energy loss. By means of internal heating, the energy loss will be less and the heating speed will be faster.

[0021] Through the above mixer, the materials can be fully mixed and stirred during the heating process, which not only saves energy consumption, but also can improve the mixing effect. [[ID=,11]]

[0022] After mixing, they are sequentially added to a prepolymerization kettle a, a prepolymerization kettle b and a polycondensation kettle, and a catalyst and a stabilizer are added to the polycondensation kettle. By adjusting the polycondensation temperature and the polycondensation time, a copolyester product is obtained. Since the catalyst and the stabilizer are conventional means for those skilled in the art, the applicant will not elaborate here. The control of the above temperature and time also belongs to the conventional means for those skilled in the art, and the applicant will not elaborate here either.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Since the raw materials are different, the esterification temperature can be adjusted according to different esterification systems to avoid excessive esterification temperature leading to the loss of a large amount of heat energy due to the loss of ethylene glycol.

[0025] 2. When the method of the present invention is adopted, the parameters of the overall product are better. By adding a self-developed mixer, the mixing effect can be better improved. By improving the mixing effect, the esterification efficiency is improved, the corresponding reaction time is reduced, and after using the equipment of the present invention, the parameters of the overall product are improved to a certain extent.

[0026] 3. In the transesterification, diols with large steric hindrance such as isosorbide are transesterified with DMT. This reaction requires a lower temperature than the direct esterification reaction, only 230 - 240°C. Moreover, the product methanol is easily separated, making it easier for the reaction to proceed in the forward direction, resulting in an increased esterification rate in the process and a reduced reaction time. The esterification reaction time only needs 2 - 3 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the workflow diagram of the present invention;

[0028] Figure 2 is the internal structure diagram of the mixer of the present invention;

[0029] Figure 3 is the side view of the cylindrical stirring assembly of the present invention;

[0030] Figure 4 is the internal structure diagram of the cylindrical stirring assembly of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] As Figures 1-4 shown:

[0032] A copolyester reaction apparatus comprises a beating tank a1, an esterification reactor a1-1, an esterification reactor b1-2, a prepolymerization kettle a4, a prepolymerization kettle b5, a polycondensation kettle 6, and a granulation device 7. The beating tank a1 is sequentially connected to the esterification reactor a1-1, the esterification reactor b1-2, the prepolymerization kettle a4, the prepolymerization kettle b5, and the polycondensation kettle 6 via pipelines. The apparatus further comprises a beating tank b2, an esterification reactor c2-1, an esterification reactor d2-2, and a mixer 3. The beating tank b2 is sequentially connected to the esterification reactor c2-1, the esterification reactor d2-2, and the mixer 3 via pipelines. The esterification reactor b1-2 is connected to the mixer 3 via a pipeline. The above-mentioned apparatus is used for a fractional esterification reaction. The mixer of the present invention is one of the core components of the present invention, wherein the mixer comprises a shell 3-1, on which a feed port 1 3-2, a feed port 2 3-3 and a discharge port 3-4 are provided, and is characterized in that a steam inlet line 3-6 and a steam outlet line 3-7 are provided at both ends of the shell 3-1, a cylindrical stirring assembly 3-5 is provided inside the shell 3-1, the cylindrical stirring assembly 3-5 is a hollow structure, a stirring blade 3-7 and a stirring rod 3-13 are provided on the cylindrical stirring assembly 3-5, and both ends of the cylindrical stirring assembly 3-5 are provided with a stirring blade 3-7 and a stirring rod 3-13. A hollow rotating shaft 3-12 is provided. A cylindrical steam heating device 3-9 is provided within the cylindrical stirring assembly 3-5. The cylindrical steam heating device 3-9 is hollow and has a plurality of jet nozzles 3-10 disposed around it. The rotating shaft 3-12 is connected to the steam heating device 3-9, and its ends are connected to the steam inlet line 3-6 and the steam outlet line 3-7 via sealed bearings, respectively, to provide steam heating. The cylindrical steam heating device 3-9 is connected to the cylindrical stirring assembly 3-5 via a fixing member 3-11. Several circular baffles 3-8 are provided on the right side of the cylindrical stirring assembly 3-5. A gap is formed between the circular baffles 3-8 and the inner wall of the housing 3-1, and the circular baffles 3-8 are provided with a plurality of circular through holes 3-8-1.

[0033] Comparative Example 1:

[0034] PTA, ethylene glycol, and 1,4-cyclohexanedimethanol were added to a beating tank a1 at a molar ratio of 1:1.1, wherein the molar ratio of ethylene glycol to 1,4-cyclohexanedimethanol was 2:3. After being fully mixed, the mixtures were successively introduced into esterification reactors a1-1 and b1-2 to obtain esterification products. The temperature of the esterification reactor a1-1 was 250°C for 3 hours, and the temperature of the esterification reactor b1-2 was 260°C for 2 hours.

[0035] The entire esterification reaction time is 5 hours.

[0036] The esterification product is subjected to polycondensation reaction and granulated to obtain a polyester product.

[0037] Comparative Example 2:

[0038] The mixture of PTA, ethylene glycol and 1,4-cyclohexanedimethanol is added to pulping tank a1 at a molar ratio of 1:1.4, wherein the molar ratio of ethylene glycol to 1,4-cyclohexanedimethanol is 2:3. After thorough mixing, it enters esterification reactors a1-1 and b1-2 successively to obtain an esterification product. The temperature of esterification reactor a1-1 is 260 °C and the time is 2.5 h, and the temperature of esterification reactor b1-2 is 260 °C and the time is 2 h;

[0039] The total esterification reaction time is 4.5 h.

[0040] The esterification product is granulated after polycondensation to obtain a polyester product.

[0041] Comparative Example 3:

[0042] The mixture of PTA, ethylene glycol and 2,2,4,4-tetramethylcyclobutanediol is added to pulping tank a1 at a molar ratio of 1:1.2, wherein the molar ratio of ethylene glycol to 2,2,4,4-tetramethylcyclobutanediol is 2:3. After thorough mixing, it enters esterification reactors a1-1 and b1-2 successively to obtain an esterification product. The temperature of esterification reactor a1-1 is 260 °C and the time is 4 h, and the temperature of esterification reactor b1-2 is 260 °C and the time is 3 h;

[0043] The total esterification reaction time is 7 h.

[0044] The esterification product is granulated after polycondensation to obtain a polyester product.

[0045] Comparative Example 4:

[0046] The mixture of PTA, ethylene glycol and 1,4-cyclohexanedimethanol is added to pulping tank a1 at a molar ratio of 1:1.1, wherein the molar ratio of ethylene glycol to 1,4-cyclohexanedimethanol is 2:3. After thorough mixing, it enters esterification reactors a1-1 and b1-2 successively to obtain an esterification product. The temperature of esterification reactor a1-1 is 250 °C and the time is 3 h, and the temperature of esterification reactor b1-2 is 250 °C and the time is 2.5 h;

[0047] The total esterification reaction time is 5.5 h.

[0048] After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain a polyester product.

[0049] Comparative Example 5:

[0050] The mixture of PTA, ethylene glycol and 2,2,4,4-tetramethylcyclobutanediol was added to the pulping tank a1 at a molar ratio of 1:1.1. Among them, the molar ratio of ethylene glycol to 2,2,4,4-tetramethylcyclobutanediol was 2:3. After thorough mixing, it successively entered the esterification reactors a1-1 and b1-2 to obtain an esterification product. The temperature of the esterification reactor a1-1 was 255°C and the time was 4.5 h. The temperature of the esterification reactor b1-2 was 255°C and the time was 3.5 h;

[0051] The total esterification reaction time was 8 h.

[0052] After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain a polyester product.

[0053] Comparative Example 6:

[0054] The mixture of PTA, ethylene glycol and isosorbide was added to the pulping tank a1 at a molar ratio of 1:1.1. Among them, the molar ratio of ethylene glycol to isosorbide was 2:3. After thorough mixing, it successively entered the esterification reactors a1-1 and b1-2 to obtain an esterification product. The temperature of the esterification reactor a1-1 was 255°C and the time was 5 h. The temperature of the esterification reactor b1-2 was 255°C and the time was 4 h;

[0055] The total esterification reaction time was 9 h.

[0056] After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain a polyester product.

[0057] Comparative Example 7:

[0058] The mixture of PTA, ethylene glycol and spiroglycol was added to the pulping tank a1 at a molar ratio of 1:1.1. The molar ratio of ethylene glycol to spiroglycol was 2:3. After thorough mixing, it successively entered the esterification reactors a1-1 and b1-2 to obtain an esterification product. The temperature of the esterification reactor a1-1 was 255°C and the time was 4.5 h. The temperature of the esterification reactor b1-2 was 255°C and the time was 4 h;

[0059] The total esterification reaction time was 8.5 h.

[0060] After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added, and the polyester product was obtained by pelletizing after the reaction.

[0061] Example 1:

[0062] As Figures 1-4 shown:

[0063] PTA and ethylene glycol were added to pulping tank a1 at a molar ratio of 1:1.1. After thorough mixing, they successively entered esterification reactor a1-1 and esterification reactor b1-2 to obtain esterification product A. The temperature of esterification reactor a1-1 was 260 °C and the time was 1.5 h. The temperature of esterification reactor b1-2 was 260 °C and the time was 1.5 h;

[0064] DMT and 1,4-cyclohexanedimethanol were added to pulping tank b2 at a molar ratio of 1:1.1. After thorough mixing, they successively entered esterification reactor c2-1 and esterification reactor d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230 °C and the time was 1.5 h. The temperature of esterification reactor d2-2 was 230 °C and the time was 1.5 h;

[0065] The total esterification reaction time was 3 h.

[0066] Esterification product A and esterification product B entered mixer 3 at a molar ratio of 2:3. Here, mixer 3 used a common static mixer on the market. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain a polyester product.

[0067] Example 2:

[0068] As Figures 1-4 shown:

[0069] PTA and ethylene glycol were added to pulping tank a1 at a molar ratio of 1:1.4. After thorough mixing, they successively entered esterification reactor a1-1 and esterification reactor b1-2 to obtain esterification product A. The temperature of esterification reactor a1-1 was 255 °C and the time was 1.5 h. The temperature of esterification reactor b1-2 was 255 °C and the time was 1 h;

[0070] DMT and 1,4-cyclohexanedimethanol were added to pulping tank b2 at a molar ratio of 1:1.4. After thorough mixing, they successively entered esterification reactor c2-1 and esterification reactor d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230 °C and the time was 1.5 h. The temperature of esterification reactor d2-2 was 230 °C and the time was 1.5 h;

[0071] The total esterification reaction time was 3 h.

[0072] Esterification product A and esterification product B entered mixer 3 at a molar ratio of 2:3. Here, mixer 3 was the mixer 3 in the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain a polyester product. Example 3:

[0073] As Figures 1-4 shown:

[0074] PTA and ethylene glycol are added to the pulping tank a1 at a molar ratio of 1:1.2. After being fully mixed, they enter the esterification reactor a1-1 and the esterification reactor b1-2 successively to obtain the esterification product A. The temperature of the esterification reactor a1-1 is 260 °C and the time is 2 h. The temperature of the esterification reactor b1-2 is 260 °C and the time is 1 h;

[0075] DMT and 1,4-cyclohexanedimethanol are added to the pulping tank b2 at a molar ratio of 1:1.2. After being fully mixed, they enter the esterification reactor c2-1 and the esterification reactor d2-2 successively to obtain the esterification product B. The temperature of the esterification reactor c2-1 is 230 °C and the time is 2 h. The temperature of the esterification reactor d2-2 is 230 °C and the time is 1 h;

[0076] The total esterification reaction time is 3 h.

[0077] The esterification product A and the esterification product B enter the mixer 3 at a molar ratio of 2:3. The mixer here is the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain the polyester product.

[0078] Example 4:

[0079] As Figures 1-4 shown:

[0080] PTA and ethylene glycol are added to the pulping tank a1 at a molar ratio of 1:1.1. After being fully mixed, they enter the esterification reactor a1-1 and the esterification reactor b1-2 successively to obtain the esterification product A. The temperature of the esterification reactor a1-1 is 250 °C and the time is 2 h. The temperature of the esterification reactor b1-2 is 250 °C and the time is 1.5 h;

[0081] DMT and 2,2,4,4-tetramethylcyclobutanediol are added to the pulping tank b2 at a molar ratio of 1:1.1. After being fully mixed, they enter the esterification reactor c2-1 and the esterification reactor d2-2 successively to obtain the esterification product B. The temperature of the esterification reactor c2-1 is 230 °C and the time is 2 h. The temperature of the esterification reactor d2-2 is 230 °C and the time is 1.5 h;

[0082] The total esterification reaction time is 3.5 h.

[0083] The esterification product A and the esterification product B enter the mixer 3 at a molar ratio of 2:3. The mixer here is the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain the polyester product.

[0084] Example 5

[0085] As Figures 1-4 shown:

[0086] PTA and ethylene glycol were added to pulping tank a1 at a molar ratio of 1:1.1. After being fully mixed, they entered esterification reactor a1-1 and esterification reactor b1-2 successively to obtain esterification product A. The temperature of esterification reactor a1-1 was 260 °C and the time was 1.5 h. The temperature of esterification reactor b1-2 was 260 °C and the time was 1.5 h.

[0087] DMT and isosorbide were added to pulping tank b2 at a molar ratio of 1:1.1. After being fully mixed, they entered esterification reactor c2-1 and esterification reactor d2-2 successively to obtain esterification product B. The temperature of esterification reactor c2-1 was 230 °C and the time was 1.5 h. The temperature of esterification reactor d2-2 was 240 °C and the time was 1 h.

[0088] The total esterification reaction time was 3 h.

[0089] Esterification product A and esterification product B entered mixer 3 at a molar ratio of 2:3. Here, mixer 3 was the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain a polyester product.

[0090] Example Six

[0091] As Figures 1-4 shown:

[0092] PTA and ethylene glycol were added to pulping tank a1 at a molar ratio of 1:1.1. After being fully mixed, they entered esterification reactor a1-1 and esterification reactor b1-2 successively to obtain esterification product A. The temperature of esterification reactor a1-1 was 245 °C and the time was 1.5 h. The temperature of esterification reactor b1-2 was 245 °C and the time was 1.5 h.

[0093] DMT and spiro-ethylene glycol were added to pulping tank b2 at a molar ratio of 1:1.1. After being fully mixed, they entered esterification reactor c2-1 and esterification reactor d2-2 successively to obtain esterification product B. The temperature of esterification reactor c2-1 was 240 °C and the time was 1.5 h. The temperature of esterification reactor d2-2 was 240 °C and the time was 1.5 h.

[0094] The total esterification reaction time was 3 h.

[0095] Esterification product A and esterification product B entered mixer 3 at a molar ratio of 2:3. Here, mixer 3 was the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain a polyester product.

[0096] Example Seven

[0097] As Figures 1-4 shown:

[0098] PTA and ethylene glycol are added to pulping tank a1 at a molar ratio of 1:1.1. After being fully mixed, they enter esterification reactor a1-1 and esterification reactor b1-2 successively to obtain esterification product A. The temperature of esterification reactor a1-1 is 260°C and the time is 2 h. The temperature of esterification reactor b1-2 is 260°C and the time is 1 h;

[0099] DMT and spiro-ethylene glycol are added to pulping tank b2 at a molar ratio of 1:1.1. After being fully mixed, they enter esterification reactor c2-1 and esterification reactor d2-2 successively to obtain esterification product B. The temperature of esterification reactor c2-1 is 230°C and the time is 2 h. The temperature of esterification reactor d2-2 is 240°C and the time is 1 h;

[0100] The total esterification reaction time is 3 h.

[0101] Esterification product A and esterification product B enter mixer 3 at a molar ratio of 1:1. Here, mixer 3 is mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain a polyester product.

[0102] Example Eight

[0103] As Figures 1-4 shown:

[0104] PTA and ethylene glycol are added to pulping tank a1 at a molar ratio of 1:1.1. After being fully mixed, they enter esterification reactor a1-1 and esterification reactor b1-2 successively to obtain esterification product A. The temperature of esterification reactor a1-1 is 260°C and the time is 1 h. The temperature of esterification reactor b1-2 is 260°C and the time is 1 h;

[0105] DMT and spiro-ethylene glycol are added to pulping tank b2 at a molar ratio of 1:1.1. After being fully mixed, they enter esterification reactor c2-1 and esterification reactor d2-2 successively to obtain esterification product B. The temperature of esterification reactor c2-1 is 230°C and the time is 1 h. The temperature of esterification reactor d2-2 is 240°C and the time is 1 h;

[0106] The total esterification reaction time is 2 h.

[0107] Esterification product A and esterification product B enter mixer 3 at a molar ratio of 1:5. Here, mixer 3 is mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain a polyester product.

[0108] Example Nine

[0109] As Figures 1-4 shown:

[0110] PTA and ethylene glycol were added to pulping tank a1 at a molar ratio of 1:1.1. After thorough mixing, they successively entered esterification reactor a1-1 and esterification reactor b1-2 to obtain esterification product A. The temperature of esterification reactor a1-1 was 255°C and the time was 1.5 h. The temperature of esterification reactor b1-2 was 255°C and the time was 1 h;

[0111] DMT and spiro-ethylene glycol were added to pulping tank b2 at a molar ratio of 1:1.1. After thorough mixing, they successively entered esterification reactor c2-1 and esterification reactor d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230°C and the time was 1.5 h. The temperature of esterification reactor d2-2 was 240°C and the time was 1 h;

[0112] The total esterification reaction time was 2 h.

[0113] Esterification product A and esterification product B entered mixer 3 at a molar ratio of 1:3. Mixer 3 here is mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain the polyester product.

[0114] Example Ten

[0115] As Figures 1-4 shown:

[0116] PTA and ethylene glycol were added to pulping tank a1 at a molar ratio of 1:1.4. After thorough mixing, they successively entered esterification reactor a1-1 and esterification reactor b1-2 to obtain esterification product A. The temperature of esterification reactor a1-1 was 250°C and the time was 1.5 h. The temperature of esterification reactor b1-2 was 250°C and the time was 1 h;

[0117] DMT and spiro-ethylene glycol were added to pulping tank b2 at a molar ratio of 1:1.4. After thorough mixing, they successively entered esterification reactor c2-1 and esterification reactor d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230°C and the time was 1.5 h. The temperature of esterification reactor d2-2 was 240°C and the time was 1 h;

[0118] The total esterification reaction time was 2.5 h.

[0119] Esterification product A and esterification product B entered mixer 3 at a molar ratio of 1:3. Mixer 3 here is mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain the polyester product.

[0120] Example Eleven

[0121] As Figures 1-4 shown:

[0122] PTA and ethylene glycol were added to the pulping tank a1 at a molar ratio of 1:1.2. After thorough mixing, they were successively fed into the esterification reactor a1-1 and the esterification reactor b1-2 to obtain the esterification product A. The temperature of the esterification reactor a1-1 was 260 °C and the time was 1 h. The temperature of the esterification reactor b1-2 was 260 °C and the time was 1 h;

[0123] DMT and spiro-ethylene glycol were added to the pulping tank b2 at a molar ratio of 1:1.2. After thorough mixing, they were successively fed into the esterification reactor c2-1 and the esterification reactor d2-2 to obtain the esterification product B. The temperature of the esterification reactor c2-1 was 230 °C and the time was 1 h. The temperature of the esterification reactor d2-2 was 240 °C and the time was 1 h;

[0124] The total esterification reaction time was 2 h.

[0125] The esterification product A and the esterification product B were fed into the mixer 3 at a molar ratio of 1:3. Here, the mixer 3 is the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain the polyester product.

[0126] Example Twelve

[0127] As Figures 1-4 shown:

[0128] PTA and ethylene glycol were added to the pulping tank a1 at a molar ratio of 1:1.2. After thorough mixing, they were successively fed into the esterification reactor a1-1 and the esterification reactor b1-2 to obtain the esterification product A. The temperature of the esterification reactor a1-1 was 260 °C and the time was 1.5 h. The temperature of the esterification reactor b1-2 was 265 °C and the time was 1.5 h;

[0129] DMT and 2,2,4,4-tetramethylcyclobutanediol were added to the pulping tank b2 at a molar ratio of 1:1.2. After thorough mixing, they were successively fed into the esterification reactor c2-1 and the esterification reactor d2-2 to obtain the esterification product B. The temperature of the esterification reactor c2-1 was 230 °C and the time was 1.5 h. The temperature of the esterification reactor d2-2 was 240 °C and the time was 1.5 h;

[0130] The total esterification reaction time was 3 h.

[0131] The esterification product A and the esterification product B were fed into the mixer 3 at a molar ratio of 1:3. Here, the mixer 3 is the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant were added to obtain the polyester product.

[0132] Example Thirteen

[0133] As Figures 1-4 shown:

[0134] PTA and ethylene glycol were added to the beating tank a1 at a molar ratio of 1:1.2, and after being fully mixed, they were successively fed into the esterification reactor a1-1 and the esterification reactor b1-2 to obtain esterification product A. The temperature of the esterification reactor a1-1 was 260°C for 1 hour, and the temperature of the esterification reactor b1-2 was 265°C for 1 hour.

[0135] DMT and isosorbide were added to beating tank b2 at a molar ratio of 1:1.2, and after thorough mixing, they were successively fed into esterification reactors c2-1 and esterification reactors d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230°C for 1 hour, and the temperature of esterification reactor d2-2 was 240°C for 1 hour.

[0136] The entire esterification reaction time is 2 h.

[0137] The esterification product A and the esterification product B enter the mixer 3 according to the molar ratio of 1:3. The mixer 3 here is the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain a polyester product.

[0138] Example 14

[0139] like Figures 1-4 As shown:

[0140] PTA and ethylene glycol were added to the beating tank a1 at a molar ratio of 1:1.2, and after being fully mixed, they were successively fed into the esterification reactor a1-1 and the esterification reactor b1-2 to obtain esterification product A. The temperature of the esterification reactor a1-1 was 260°C for 1.5 hours, and the temperature of the esterification reactor b1-2 was 265°C for 1.5 hours.

[0141] DMT and isosorbide were added to beating tank b2 at a molar ratio of 1:1.2, and after thorough mixing, they were successively fed into esterification reactors c2-1 and esterification reactors d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230°C for 1.5 h, and the temperature of esterification reactor d2-2 was 240°C for 1.5 h.

[0142] The entire esterification reaction time is 3 h.

[0143] The esterification product A and the esterification product B enter the mixer 3 according to the molar ratio of 1:5. The mixer 3 here is the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain a polyester product.

[0144] Example 15

[0145] like Figures 1-4 As shown:

[0146] PTA and ethylene glycol were added to the beating tank a1 at a molar ratio of 1:1.2, and after being fully mixed, they were successively fed into the esterification reactor a1-1 and the esterification reactor b1-2 to obtain esterification product A. The temperature of the esterification reactor a1-1 was 260°C for 1 hour, and the temperature of the esterification reactor b1-2 was 265°C for 1.5 hours.

[0147] DMT and isosorbide were added to beating tank b2 at a molar ratio of 1:1.2, and after thorough mixing, they were successively fed into esterification reactors c2-1 and esterification reactors d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230°C for 1 hour, and the temperature of esterification reactor d2-2 was 240°C for 1.5 hours.

[0148] The entire esterification reaction time was 2.5 h.

[0149] The esterification product A and the esterification product B enter the mixer 3 according to the molar ratio of 2:3. The mixer 3 here is the mixer 3 of the present invention. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain a polyester product.

[0150] Example 16

[0151] like Figures 1-4 As shown:

[0152] PTA and ethylene glycol were added to the beating tank a1 at a molar ratio of 1:1.2, and after being fully mixed, they were successively fed into the esterification reactor a1-1 and the esterification reactor b1-2 to obtain esterification product A. The temperature of the esterification reactor a1-1 was 260°C for 1.5 hours, and the temperature of the esterification reactor b1-2 was 265°C for 1.5 hours.

[0153] DMT and isosorbide were added to beating tank b2 at a molar ratio of 1:1.2, and after thorough mixing, they were successively fed into esterification reactors c2-1 and esterification reactors d2-2 to obtain esterification product B. The temperature of esterification reactor c2-1 was 230°C for 1.5 h, and the temperature of esterification reactor d2-2 was 240°C for 1.5 h.

[0154] The entire esterification reaction time is 3 h.

[0155] The esterification product A and the esterification product B enter the mixer 3 according to the molar ratio of 2:3. The mixer here uses an ordinary static mixer. After polycondensation, 0.3% pentaerythritol stearate and 100 ppm antioxidant are added to obtain a polyester product.

[0156] The copolyester obtained in the above example was subjected to DSC, intrinsic viscosity and other tests. At the same time, a 2 mm thick color plate was prepared to examine whether the product had injection molding defects and the color plate transmittance test results were as follows:

[0157]

[0158]

[0159] It is found by comparison that when the co-esterification is carried out in an ordinary way, there are many defects in the produced products, and the esterification reaction time is relatively long. The data of the glass transition temperature (°C), particle L value, oxidation induction temperature (°C), color plate L value and color plate light transmittance (%) of the products are relatively poor. When the separate esterification production is adopted, the above data have been improved to a certain extent. When the special mixer of the present invention is adopted, the above values reach the optimal state, that is, by using the mixer of the present invention, the comprehensive performance of the products has been further improved.

Claims

1. A copolyester reaction device, comprising a pulping tank a (1), an esterification reactor a (1-1), an esterification reactor b (1-2), a prepolymerization kettle a (4), a prepolymerization kettle b (5), a polycondensation kettle (6) and a granulation device (7). The pulping tank a (1) is sequentially connected to the esterification reactor a (1-1), the esterification reactor b (1-2), the prepolymerization kettle a (4), the prepolymerization kettle b (5) and the polycondensation kettle (6) through pipelines, and is characterized in that, A beating tank b (2), an esterification reactor c (2-1), an esterification reactor d (2-2) and a mixer (3) are also provided. The beating tank b (2) is connected to the esterification reactor c (2-1), the esterification reactor d (2-2) and the mixer (3) in sequence through pipelines, and the esterification reactor b (1-2) is connected to the mixer (3) through a pipeline.

2. The copolyester reaction device according to claim 1, wherein: The mixer comprises a shell (3-1), and the shell (3-1) is provided with a first feed port (3-2), a second feed port (3-3) and a discharge port (3-4), and is characterized in that a steam inlet pipeline (3-6) and a steam outlet pipeline (3-7) are respectively provided at both ends of the shell (3-1), and a cylindrical stirring component (3-5) is provided inside the shell (3-1), and the cylindrical stirring component (3-5) is a hollow structure. A stirring blade (3-7) and a stirring rod (3-13) are provided on the cylindrical stirring component (3-5), and a rotating shaft (3- 12), the rotating shaft (3-12) is a hollow structure, a cylindrical steam heating device (3-9) is provided inside the cylindrical stirring assembly (3-5), the cylindrical steam heating device (3-9) is a hollow structure and is provided with a plurality of jet nozzles (3-10) around it, the rotating shaft (3-12) is connected to the steam heating device (3-9), and both ends are connected to the steam inlet pipeline (3-6) and the steam outlet pipeline (3-7) through sealed bearings to form steam heating, and the cylindrical steam heating device (3-9) is connected to the cylindrical stirring assembly (3-5) through a fixing member (3-11).

3. The copolyester reaction device according to claim 2, wherein A plurality of circular baffles (3-8) are provided on the right side of the cylindrical stirring assembly (3-5), a gap is formed between the circular baffles (3-8) and the inner wall of the shell (3-1), and a plurality of circular through holes (3-8-1) are provided on the circular baffles (3-8).

4. A method for producing a copolyester, which uses the copolyester reaction device described in any one of claims 1-3 for the reaction, characterized in that, The following steps are involved: Step 1: PTA and ethylene glycol are added into a beating tank a (1) at a molar ratio of 1:1.1-1.4, and after being fully mixed, they are successively fed into an esterification reactor a (1-1) and an esterification reactor b (1-2) to obtain an esterification product A; Step 2: adding DMT to any one of 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethylcyclobutanediol, isosorbide, and spiroethylene glycol at a molar ratio of 1:1.1-1.4 into a beating tank b (2), fully mixing, and successively entering an esterification reactor c (2-1) and an esterification reactor d (2-2) to obtain an esterification product B; Step 3: adding the esterification product A and the esterification product B into the mixer (3) at a molar ratio of 1:1-5, and fully mixing the two esterification products through the mixer (3); Step 4: adding the mixed products to prepolymerization kettle a (4), prepolymerization kettle b (5) and polycondensation kettle (6) in sequence, and adding a catalyst and a stabilizer to the polycondensation kettle (6) to obtain a copolyester product; Step 5: Before granulation and molding, the release agent and flow enhancer are added through the additive injection system; Step 6: Perform granulation operation through granulation equipment.

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