TWI651341B - Method and system for solid state polymerization of nylon 66 - Google Patents

Abstract

The invention provides a method for solid-state polymerizing nylon 66, comprising providing a plurality of nylon 66 particles, performing a preheating step, and performing a solid-state polymerization step. The solid state polymerization step includes a feeding step, a heating polymerization step, and a deoxidizing and drying step. The nylon 66 particles are heated with a warm gas having a flow rate of 600 m ³ / hr to 1000 m ³ / hr to obtain relative Polyamide 66 polycondensation particles having a viscosity of 3.05 to 3.26 and a molecular weight distribution index of 1.95 to 2.15. The present invention also provides a solid-state polymerization system applied to a method for solid-state polymerizing nylon 66 to perform solid-state polymerization of nylon 66. This can effectively improve the relative viscosity, molecular weight distribution index, and solid state polymerization performance of nylon 66.

Description

Method and system for solid polymerizing nylon 66

The invention relates to a method and a system for polymerizing nylon 66, in particular to a method and a system for polymerizing nylon 66 in a solid state.

Nylon 66 (Nylon 66), also known as polyamide 66 and nylon 66, is formed by the alternate polycondensation of hexamethylenediamine molecules and adipic acid molecules. Since both hexamethylenediamine molecules and adipic acid molecules have 6 carbon atoms, Nylon 66 got its name. Nylon 66 has excellent heat resistance and mechanical properties, with high strength and high impact resistance. It can be widely used in aerospace, automotive, electrical and electronic, construction, fitness equipment, power tools, industrial components and agricultural machinery, etc. The field is of great importance in related industries.

In terms of physical properties, due to the low viscosity of nylon 66, it has good fluidity and can be used to process thin components. However, when the molecular weight of nylon 66 is too low, the relative viscosity of the melt will be small, and the phenomenon of flooding, leakage and other phenomena during the spinning process is prone to occur. The yarn produced will have more wool and ends. , Elongation at break is also low. Therefore, how to effectively increase and control the viscosity of nylon 66 is a key factor for its effective application in the textile-related industries.

At present, the polymerization of nylon 66 is mostly solid-state polymerization. state polymerization). Solid state polymerization, also known as solid phase polymerization, is a polymerization reaction of polymer monomers or oligomers in the solid state. Solid state polymerization has the characteristics of low reaction activation energy and non-reaction induction period, which can improve the degree of polymer polymerization and product quality. In order to effectively improve the polymerization efficiency of solid state polymerization, U.S. Patent No. 5,859,180 discloses a method for solid phase polycondensation of polyamide to effectively improve the viscosity of polyamide resin, while U.S. Patent No. 5,576,415 discloses a solid phase polycondensation polyamide. The method is to dry the polyamide and increase the molecular weight of the polyamide through a solid phase treatment step.

Therefore, how to further improve the solid-state polymerization rate and product quality of nylon, especially to develop a high-performance nylon 66 solid-state polymerization method, in order to increase the industrial applicability of nylon 66, has become the development direction of the relevant academic industry.

The purpose of the present invention is to provide a solid-state polymerization method for polymerizing nylon 66, so that the reaction rate thereof is greatly increased, and the molecular weight and viscosity of nylon 66 can be effectively increased to improve the solid-state polymerization efficiency of nylon 66.

In order to achieve the above object, one embodiment of the method of the present invention is to provide a method for solid-state polymerizing nylon 66, including the following steps: providing a plurality of nylon 66 particles, performing a preheating step, and performing a solid-state polymerization step.

A preheating step is performed to heat the nylon 66 particles to a preheating temperature. The solid state polymerization step includes performing a feeding step, performing a heating polymerization step, and performing a deoxidizing and drying step. Performing a feeding step is to put the nylon 66 particles that have undergone the preheating step into a solid-state polymerization system, and apply a vacuum to the solid-state polymerization system to introduce a warm gas, wherein the flow of the warm gas can be 600 m ³ / hr To 1000m ³ / hr. Performing a heating polymerization step is to use the heat carried by the warm gas to circulate in the solid state polymerization system to heat the nylon 66 particles that have undergone the preheating step, so that the nylon 66 particles react at a heating temperature for a heating time. Performing a deoxidizing and drying step is to use a warm gas to circulate in a solid state polymerization system to remove one of oxygen and a moisture of nylon 66 particles, so as to obtain a plurality of nylon 66 polycondensation particles, among which the relative viscosity of sulfuric acid Viscosity (RV) may be 3.05 to 3.26, and the molecular weight distribution index (PDI) of nylon 66 polycondensation particles may be 1.95 to 2.15.

According to the aforementioned method of solid-state polymerizing nylon 66, the preheating temperature may be 60 ° C to 80 ° C.

According to the aforementioned method of solid-state polymerizing nylon 66, the warm gas may be nitrogen.

According to the aforementioned method of solid-state polymerizing nylon 66, the warm gas flow rate may be 800 m ³ / hr.

According to the aforementioned method of solid-state polymerizing nylon 66, the heating temperature may be 120 ° C to 170 ° C, and preferably 166 ° C.

According to the aforementioned method of solid-state polymerizing nylon 66, the heating time may be 18 hours to 22 hours, and preferably 20 hours.

Therefore, in the method for solid-state polymerizing nylon 66 of the present invention, the nylon 66 particles are pre-heated before the solid-state polymerization reaction is performed, so as to reduce the time required for the raw materials to heat up when the nylon 66 undergoes solid-state polymerization. Furthermore, the warm gas The circulation in the combined system can not only preheat the nylon 66 particles, but also continue to provide heat to the nylon 66 particles after the preheating step, so that it can reach the temperature required for the solid state polymerization reaction, and the reaction generated after the reaction is completed. Oxygen and moisture are taken away to avoid the occurrence of reverse reactions, thereby greatly improving the efficiency of the reaction.

One embodiment of the structural aspect of the present invention is to provide a solid state polymerization system, which is applied to the aforementioned method of solid state polymerization of nylon 66. The aforementioned solid state polymerization system includes a polymerization reaction tower and a gas circulation device. The polymerization reaction tower includes a raw material tank, a rotary feeding valve, and a solid state polymerization tank. The raw material tank has a raw material input port, a discharge port, and a vacuum device. The raw material tank is used for containing a raw material, and the vacuum device is arranged on the raw material tank. The rotary feeding valve group is set at the discharge port to control the raw material supply from the raw material tank to the outside. The solid-state polymerization tank connection group is set on the rotary feeding valve, and the solid-state polymerization tank receives the raw material supplied from the raw material tank. The gas circulation equipment provides a gas circulating in a solid state polymerization system. The aforementioned gas circulation equipment includes a gas supply equipment and a return air equipment. The air supply device is used to provide the aforementioned gas, and the aforementioned air supply device includes an air inlet pipe and an air outlet pipe, wherein the air inlet pipe is connected between the air supply equipment and the solid state polymerization tank, and the air outlet pipe is arranged in a solid Aggregation tank. The return air device is connected between the raw material tank and the air outlet pipe, and the aforementioned gas is circulated through the gas circulation device, the solid polymerization tank and the raw material tank.

According to the aforementioned solid state polymerization system, the return air equipment includes a first through pipe and a second through pipe, wherein the first through pipe has a first end and a second end, and the first end is arranged on the air outlet pipe. The second end group is set in the raw material tank to introduce the aforementioned gas into the raw material tank through the first through tube, and the second through tube has a front end and a rear end, and the front end group is set in the raw material tank. Set up in the air duct In order to drain the aforementioned gas back to the gas outlet pipe through the second through pipe.

According to the aforementioned solid state polymerization system, the solid state polymerization system further includes a heating device and a deaeration drying device. The heating equipment is arranged above the air inlet pipe to heat the aforementioned gas, and the deoxidizing and drying equipment is arranged above the air outlet pipe to remove one of the foregoing gas, oxygen and water.

In this way, the solid-state polymerization system of the present invention can use the return air equipment in the gas circulation equipment to return the gas with heat to the raw material tank to use the residual temperature of the return air gas to pre-heat the raw materials, which can not only greatly improve the solid The rate of the polymerization reaction can also make full use of the residual heat carried by the gas, thereby reducing the waste of energy while achieving the purpose of high-efficiency solid polymerized nylon 66.

The above summary is intended to provide a simplified summary of the content disclosed by the present invention, so that the reader can have a basic understanding of the content disclosed by the present invention. The above summary is not a complete summary of what is disclosed in the present invention, and it is not intended to point out important or critical elements of the present invention, nor is it intended to limit or define the scope of the present invention.

100‧‧‧ solid state polymerization system

100a‧‧‧ solid state polymerization system

200‧‧‧ polymerization tower

210‧‧‧ raw material tank

211‧‧‧ Raw material input

212‧‧‧Discharge port

213‧‧‧Evacuation device

220‧‧‧Rotary feeding valve

230‧‧‧Solid Polymerization Tank

300‧‧‧Gas circulation equipment

310‧‧‧Gas supply equipment

311‧‧‧Air inlet pipe

312‧‧‧outlet

320‧‧‧Return air equipment

321‧‧‧First tube

321a‧‧‧First end

321b‧‧‧Second End

322‧‧‧Secondary tube

322a‧‧‧Front

322b‧‧‧back

400‧‧‧Heating equipment

500‧‧‧ deaeration drying equipment

S1‧‧‧ provides multiple nylon 66 particles

S2‧‧‧ performs a preheating step

S3‧‧‧ performs a solid state polymerization step

S31‧‧‧ performs a feeding step

S32‧‧‧ performs a heating polymerization step

S33‧‧‧ performs a deaeration drying step

In order to make the above and other objects, features, advantages, and embodiments of the present invention more comprehensible, the description of the drawings is as follows: FIG. 1 is a diagram showing a solid polymerized nylon 66 according to an embodiment of the method of the present invention. Method flow chart of the method; FIG. 2 is a schematic diagram showing the structure of a solid state polymerization system according to an embodiment of the present invention; and FIG. 3 is a schematic structural diagram of a solid state polymerization system according to another embodiment of the structural aspect of the present invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. For the sake of clarity, many practical details will be explained in the following description. It should be understood, however, that these practical details should not be used to limit the invention. That is, in some embodiments of the present invention, these practical details are not necessarily described in detail. In addition, in order to simplify the drawings, some conventional structures and components will be shown in the drawings in a simple and schematic manner, and repeated components may be represented by the same number.

<Method for solid-state polymerizing nylon 66>

Please refer to FIG. 1, which is a flowchart showing the steps of a method for solid-state polymerizing nylon 66 according to an embodiment of the method of the present invention. The method for solid-state polymerizing nylon 66 includes the following steps: providing a plurality of nylon 66 particles S1, performing a preheating step S2, and performing a solid-state polymerization step S3.

Provide multiple nylon 66 particles S1 series provide nylon 66 particles for subsequent polymerization. The melting point of nylon 66 particles can be 253 ° C to 263 ° C, the relative viscosity of sulfuric acid can be 2.38 to 2.5, and its weight average molecular weight can be 2.05. To 2.2. The aforementioned nylon 66 particles may also be selected from commercially available products.

A pre-heating step S2 is performed to heat the above-mentioned nylon 66 particles to a pre-heating temperature, wherein the pre-heating temperature may be 60 ° C to 80 ° C, and the aforementioned pre-heating temperature is lower than the melting point of the nylon 66 particles and lower than the nylon 66 for solid state polymerization The temperature required for the reaction. A preheating step S2 is performed by preheating the above-mentioned nylon 66 particles by the remaining thermal energy of the warm gas in a solid state polymerization step S3, so as to reduce the reaction time for performing a solid state polymerization step S3 and make the obtained nylon The molecular weight distribution of 66 polycondensation particles is more concentrated, which greatly improves the reaction yield and efficiency of nylon 66 solid state polymerization.

Performing a solid state polymerization step S3 includes performing a feeding step S31, performing a heating polymerization step S32, and performing a deoxidizing and drying step S33.

Performing a feeding step S31 is to put the nylon 66 particles which have undergone the preheating step into a solid-state polymerization system, and apply a vacuum to the solid-state polymerization system, and then introduce a warm gas, wherein the warm gas may be nitrogen, and the warm The flow rate of the gas may be 600 m ³ / hr to 1000 m ³ / hr, and preferably 800 m ³ / hr. Applying a vacuum to the solid state polymerization system and then introducing nitrogen for subsequent reactions can avoid reverse reactions caused by active molecules such as oxygen in the air, and the flow rate of warm gas is preferably 0.4m / sec to 0.7m / sec. .

A heating polymerization step S32 is performed by circulating the heat carried by the warm gas in a solid state polymerization system to heat the nylon 66 particles that have undergone the preheating step, so that the nylon 66 particles react at a heating temperature for a heating time, wherein The heating temperature may be 120 ° C to 170 ° C, preferably 166 ° C, and the heating time may be 18 hours to 22 hours, preferably 20 hours. Heating the nylon 66 particles with the above heating time can make the nylon 66 particles sulfuric acid The relative viscosity is greatly increased to obtain the required nylon 66 polycondensation particles.

A step of removing oxygen and drying S33 is to use warm gas to circulate in a solid state polymerization system to remove one of oxygen and one moisture of nylon 66 particles to obtain a plurality of nylon 66 polycondensation particles. Oxidation of moisture and by-products of solid state polymerization Extraction can further prevent the reverse reaction of the polymerization reaction to increase the efficiency of nylon 66 solid state polymerization. Accordingly, the relative viscosity of sulfuric acid of the nylon 66 polycondensation particles prepared by the above-mentioned method of solid-state polymerizing nylon 66 is 3.05 to 3.26, and the molecular weight distribution index of the nylon 66 polycondensation particles is 1.95 to 2.15.

<Solid State Polymerization System of Nylon 66>

Please refer to FIG. 2, which is a schematic structural diagram of a solid-state polymerization system 100 according to an embodiment of a structural aspect of the present invention. The solid state polymerization system 100 is applied to the aforementioned method of solid state polymerization of nylon 66. The solid-state polymerization system 100 includes a polymerization reaction column 200 and a gas circulation device 300.

The polymerization reaction column 200 includes a raw material tank 210, a rotary feeding valve 220, and a solid state polymerization tank 230. The raw material tank 210 has a raw material input port 211, a discharge port 212, and a vacuum device 213. The raw material tank 210 is used to contain a raw material input from the raw material input port 211, and the vacuum device 213 is arranged on the raw material tank 210 to apply a vacuum to the solid-state polymerization system 100. A group of rotary feeding valves 220 is provided at the discharge port 212 and is used to control the supply of raw materials from the raw material tank 210 to the outside. The solid-state polymerization tank 230 is connected to the rotary feeding valve 220 and receives raw materials supplied from the raw material tank 210.

The gas circulation device 300 is used to provide a gas circulating in the solid state polymerization system 100. The gas circulation device 300 includes a gas supply device 310 and a return air device 320. The gas supply device 310 is used to provide the foregoing gas. The gas supply device 310 includes an air inlet pipe 311 and an air outlet pipe 312. The air inlet pipe 311 is connected between the air supply device 310 and the solid polymerizing tank 230, and the air outlet pipe 312 is Set on the solid-state polymerization tank 230. Return air equipment 320 is connected to the raw material tank 210 and the air outlet pipe 312 And the aforementioned gas is circulated through the gas circulation device 300, the solid-state polymerization tank 230, and the raw material tank 210.

As shown in FIG. 2, the return air device 320 further includes a first through pipe 321 and a second through pipe 322. The first through pipe 321 has a first end 321 a and a second end 321 b. The first end The 321a group is arranged above the air outlet pipe 312, and the second end 321b is arranged in the raw material tank 210 to introduce the aforementioned gas into the raw material tank 210 through the first through pipe 321, and the second through pipe 322 has a front end 322a and a rear end 322b, the front end 322a is arranged in the raw material tank 210, and the rear end 322b is arranged above the air outlet pipe 312, so as to draw the aforementioned gas back to the air outlet pipe 312 through the second through pipe 322.

Please refer to FIG. 3, which is a schematic structural diagram of a solid state polymerization system 100a according to another embodiment of the structural aspect of the present invention. The structure of the solid-state polymerization system 100 a is similar to that of the solid-state polymerization system 100 of FIG. 2, and details of the same element structure are not described again.

As shown in FIG. 3, the solid-state polymerization system 100 a further includes a heating device 400 and an oxygen removal drying device 500. The heating equipment 400 is set above the air inlet pipe 311 to heat the aforementioned gas, and the deoxidizing and drying equipment 500 is set above the air outlet pipe 312. The aforementioned gas will generate by-product oxygen produced by the solid state polymerization reaction It is taken away from the solid state polymerization tank 230 with moisture and processed by the deoxidizing and drying equipment 500 to remove oxygen and moisture from the gas.

<Examples and Comparative Examples> Solid polymer nylon 66

The nylon 66 polycondensate provided in this test uses the aforementioned It is produced by the method of solid-state polymerizing nylon 66 and the aforementioned solid-state polymerization system 100a.

When preparing the nylon 66 polycondensate, a plurality of nylon 66 particles are first provided, and the nylon 66 particles are fed from the raw material input port 211 into the raw material tank 210 of the polymerization reaction tower 200, wherein the relative viscosity of the sulfuric acid of the nylon 66 particles is 2.48 ± 0.1, and the moisture content is less than 6000 ppm. Then, a vacuum is applied to the solid-state polymerization system 100a by using the evacuation device 213, and the gas supply device 310 of the gas circulation device 300 is used to pass in a flow of 600 m ³ / hr to 1000 m ³ / hr and a temperature of 120 ° C to 170 ° C Hot nitrogen, specifically, Example 1 is a warm nitrogen of 800m ³ / hr and a temperature of 166 ° C, and Example 2 is a warm nitrogen of 800m ³ / hr and a temperature of 170 ° C. Example 3 is into 600m ³ / hr, a temperature of 166 deg.] C of warm nitrogen, and Example 4 was passed through 800m ³ / hr, a temperature of 175 deg.] C of warm nitrogen. The aforementioned warm nitrogen is heated by the heating device 400 and circulates in the solid state polymerization system 100a through the pipeline of the gas supply device 310.

Next, a preheating step is performed, which introduces the warm nitrogen circulating in the gas supply device 310 and the solid-state polymerization tank 230 into the return air device 320 of the gas circulation device 300, so that the warm nitrogen enters the raw material tank 210 to feed the raw materials. The nylon 66 particles in the tank 210 are preheated, and the temperature of the nylon 66 particles is raised from normal temperature to 60 ° C to 80 ° C. Specifically, the preheating temperature of Example 1 is 70 ° C, and the preheating of Example 2 is preheating. The temperature was 75 ° C, the preheating temperature of Example 3 was 60 ° C, and the preheating temperature of Example 4 was 80 ° C. Pre-heating the nylon 66 particles can raise the temperature of the nylon 66 particles in advance to reduce the heating temperature and reaction time of the nylon 66 particles during the solid state polymerization reaction.

After the preheating step is completed, the nylon 66 particles can be subjected to a solid state polymerization step. When performing the solid state polymerization step, first, the pre-heated nylon 66 particles are controlled by the rotary feeding valve 220 to be sent from the material outlet 210 of the raw material tank 210 to the solid state polymerization tank 230 of the polymerization tower 200 to establish the process. Particle size of nylon 66 particles required for solid state polymerization. Next, the nylon 66 particles are heated by warm nitrogen to perform a heating step, and the nylon 66 particles are heated at a temperature of 120 ° C to 170 ° C for 18 hours to 22 hours. Specifically, Example 1 is heated at 166 ° C. For 18 hours, Example 2 was heated at 170 ° C for 18 hours, Example 3 was heated at 166 ° C for 22 hours, and Example 4 was heated at 175 ° C for 18 hours. During the heating step, the nylon 66 particles located in different parts of the bottom, middle, and upper layers of the solid state polymerization tank 230 will be heated to different temperatures according to the degree of heating by the warm nitrogen, so that the nylon 66 in the solid state polymerization tank 230 will be heated to different temperatures. The particles can undergo solid-state polymerization in sequence. When the nylon 66 in the bottom of the solid-state polymerization tank 230 completes the solid-state polymerization, the middle and upper layers of the nylon 66 in the solid-state polymerization tank 230 have also been heated to a temperature suitable for the solid-state polymerization, which can be used for subsequent reactions. proceed. With this, under the high temperature state, the nylon 66 particles in the solid state polymerization tank 230 can move and collide with the carboxyl group at the molecular end of the non-crystalline region and the amine group at the other end of the molecule. To achieve the effect of increasing the molecular weight and viscosity of nylon 66.

Next, a deoxidizing and drying step is performed, which uses a deoxidizing and drying device 500 to circulate warm nylon, oxygen, moisture, and other nylon 66 particles that will be circulated in the solid state polymerization system 100a to remove the reaction by-products produced by the solid state polymerization reaction to obtain A plurality of nylon 66 polycondensation particles. The relative viscosity of sulfuric acid of the nylon 66 polycondensation particles prepared by the method for solid-state polymerizing nylon 66 and the system of the present invention is 3.15 ± 0.1, and the molecular weight distribution index is 2.05 ± 0.1.

In this test, the relative viscosity of sulfuric acid and molecular weight distribution index of nylon 66 polycondensation particles prepared under the conditions of each example were further analyzed. In terms of sulfuric acid relative viscosity test, 0.25 g of nylon 66 polycondensation particles are dissolved in a manner of 1 g relative to 100 ml of sulfuric acid with a concentration of 96 weight percent, and then placed in a viscosity tube of a viscosity meter for measurement . In terms of molecular weight distribution index test, before the test, nylon 66 polycondensation particles prepared by the solid-state polymerization method of nylon 66 of the present invention are subjected to acetylation modification, and then using a gel permeation chromatography (Gel Permeation Chromatography, (GPC) The molecular weight distribution index of the nylon 66 polycondensation particles subjected to ethionization was measured. The values of preheating temperature, nitrogen flow rate, heating temperature and heating time used in different examples in this experiment are listed in Table 1 below.

As shown in the results of Table 1, when the heating temperature is 166 ° C, the preheating temperature of Example 1 is 70 ° C, and the preheating temperature of Example 3 is 60 ° C, and the capacity of both can reach 10000kg / day. ; In the case of a heating temperature of 170 ° C, the preheating temperature of Example 2 is 75 ° C, and its production capacity can reach 10,000 kg / day; and under the condition that the heating temperature is 175 ° C, the solid polymerized nylon 66 of the present invention is prepared at a preheating temperature of 80 ° C in Example 4, and the production capacity can also reach 10,000 kg / day. The results of the above examples show that the solid state polymerization of nylon 66 particles using the pre-heating temperature and heating temperature of the method for solid state polymerization of nylon 66 of the present invention can effectively improve the production capacity of nylon 66 polycondensation particles.

In terms of nitrogen flow rate, as shown in Table 1, when the heating temperature is 166 ° C and the preheating temperature is between 60 ° C and 80 ° C, the nitrogen flow rate of Example 1 is 800 m ³ / hr, and the nitrogen flow rate of Example 3 The flow rate is 600 m ³ / hr, and the production capacity of both Examples 1 and 3 can reach 10,000 kg / day. The relative viscosity and PDI of the nylon 66 polycondensation particles of Example 1 are 3.15 and 2.05, respectively. The relative viscosity and PDI of the nylon 66 polycondensation particles were 3.14 and 2.05, respectively; and under the condition that the nitrogen flow rate was 800 m ³ / hr, the capacity of Examples 2 and 4 could also reach 10,000 kg / day, of which Example 2 The relative viscosity and PDI of the nylon 66 polycondensation particles were 3.20 and 2.04, respectively, while the relative viscosity and PDI of the nylon 66 polycondensation particles of Example 3 were 3.26 and 2.02, respectively. The results of the above examples show that the solid state polymerization of nylon 66 particles with the nitrogen flow rate of the method for solid state polymerization of nylon 66 of the present invention can effectively improve the efficiency of nylon 66 solid state polymerization.

In terms of heating time, as shown in Table 1, under the condition of achieving the same capacity, the method of performing the solid polymerized nylon 66 of the present invention under the conditions of Example 1, Example 3 and Example 4 can shorten the heating time to 18 hours, and the method of carrying out the solid polymerization of nylon 66 of the present invention under the conditions of Example 2 can also shorten the heating time of nylon 66 pellets to 22 hours, showing that the method of carrying out the solid polymerization of nylon 66 of the present invention for nylon 66 granules Polymerization can effectively reduce nylon 66 The heating time of the polycondensation particles makes their polymerization more efficient.

This experiment also includes Comparative Example 1. The values of the preheating temperature, nitrogen flow rate, heating temperature, and heating time used in Comparative Example 1 are listed in Table 2 below.

From the results in Tables 1 and 2, it can be known that when the nitrogen flow rate and the heating temperature conditions are the same, and the relative viscosity of the obtained nylon 66 polycondensation particles reaches 3.05 to 3.26, and the PDI is 1.95 to 2.15, the The preheating temperature is 70 ° C, the heating time is 18 hours, and its production capacity is 10,000 kg / day, while Comparative Example 1 does not perform the preheating step. The heating time of its nylon 66 polycondensation particles is 26 hours, and the production capacity is 7,500 kg / day. The above results show that compared with Example 1, the production capacity of nylon 66 solid-state polymerization under the conditions of Comparative Example 1 is lower, and the heating time required is longer, indicating that nylon 66 without the preheating step The solid state polymerization method has poor polymerization efficiency, and the preheating step has a great influence on the heating time of the solid state polymerization of nylon 66 and its capacity.

To sum up, the advantages of the method for solid-state polymerizing nylon 66 of the present invention and its system are as follows: First, the method for solid-state polymerizing nylon 66 of the present invention pre-heats nylon 66 particles before solid-state polymerization reaction to reduce The time required for the raw materials to heat up during the solid state polymerization of nylon 66, which can effectively increase the relative viscosity of nylon 66 polycondensation particles and increase the molecular weight dispersion uniformity, which greatly increases the reaction efficiency. plus.

Second, continuous circulation of warm gas in a solid state polymerization system can not only preheat nylon 66 particles, but also continue to provide heat to the nylon 66 particles after the preheating step, and can generate the reaction after the polymerization reaction is completed. The oxygen and moisture are taken away to avoid the occurrence of reverse reactions, which greatly improves the reaction efficiency.

Third, the temperature of the return air gas is used to pre-heat the nylon 66 raw material, which can not only greatly improve the solid-state polymerization reaction performance of nylon 66, but also make full use of the residual heat carried by the gas, so that it can achieve the purpose of polymerizing nylon 66 efficiently. , Can also reduce energy waste.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be determined by the scope of the attached patent application.

Claims (10)

A method for solid-state polymerizing nylon 66 includes the following steps: providing a plurality of nylon 66 particles; and performing a preheating step, which is heating the nylon 66 particles to a preheating temperature, wherein the preheating temperature is 60 ° C to 80 ° C; and performing a solid state polymerization step, including the following steps: performing a feeding step, which is to put the nylon 66 particles subjected to the preheating step into a solid state polymerization system, and apply the solid state polymerization system to the solid state polymerization system. After the vacuum, a warm gas is introduced, wherein the flow rate of the warm gas is 600m ³ / hr to 1000m ³ / hr; a heating polymerization step is performed, which uses the heat carried by the warm gas to circulate in the solid state polymerization system. To heat the nylon 66 particles that have undergone the preheating step, so that the nylon 66 particles react at a heating temperature for a heating time; and perform a deoxidizing and drying step, which uses the warm gas in The solid state polymerization system circulates and removes one of the nylon 66 particles oxygen and a water to obtain a plurality of nylon 66 polycondensation particles, wherein the relative viscosity of the sulfuric acid of the nylon 66 polycondensation particles is 3.0 The molecular weight distribution index of these nylon 66 polycondensation particles is 1.95 to 2.15. The method for solid-state polymerizing nylon 66 according to item 1 of the patent application scope, wherein the warm gas is nitrogen. The method for solid-state polymerizing nylon 66 according to item 1 of the scope of patent application, wherein the flow rate of the warm gas is 800 m ³ / hr. The method for solid-state polymerizing nylon 66 according to item 1 of the patent application scope, wherein the heating temperature is 120 ° C to 170 ° C. The method for solid-state polymerizing nylon 66 according to item 4 of the scope of patent application, wherein the heating temperature is 166 ° C. The method for solid-state polymerizing nylon 66 according to item 1 of the patent application range, wherein the heating time is 18 hours to 22 hours. The method for solid-state polymerizing nylon 66 according to item 6 of the patent application, wherein the heating time is 20 hours. A solid-state polymerization system, which is applied to the method for solid-state polymerization of nylon 66 described in item 1 of the scope of patent application. The solid-state polymerization system includes a polymerization reaction tower including a raw material tank having a raw material input. Port, a discharge port and a vacuum device, wherein the raw material tank is used for containing a raw material, the vacuum device is set on the raw material tank; a rotary feeding valve is set on the discharge port, For controlling the raw material to be supplied from the raw material tank outward; and a solid state polymerization tank connected to the rotary feeding valve, and the solid state polymerizing tank receives the raw material supplied from the raw material tank; and a gas circulation device, A gas is provided to circulate in the solid state polymerization system. The gas circulation device includes: a gas supply device for supplying the gas. The gas supply device includes an air inlet pipe and an air outlet pipe, wherein the air inlet pipe is connected to Between the gas supply device and the solid state polymerization tank, the gas outlet pipe set is arranged above the solid state polymerization tank; and a return air device connected between the raw material tank and the gas outlet pipe, and the gas passes through the gas circulation Preparation of the solid-state polymerization vessel to form a loop and the raw material tank. The solid state polymerization system according to item 8 of the scope of patent application, wherein the return air device includes: a first through pipe, the first through pipe has a first end and a second end, and the first end is arranged in the Above the gas outlet pipe, the second end is arranged in the raw material tank to introduce the gas into the raw material tank through the first through pipe; and a second through pipe, the second through pipe has a front end And a rear end, the front end group is disposed on the raw material tank, and the rear end group is disposed on the air outlet pipe to draw the gas back into the air outlet pipe through the second through pipe. The solid-state polymerization system according to item 8 of the scope of patent application, wherein the solid-state polymerization system further includes: a heating device arranged on the air inlet pipe for heating the gas; and a deoxidizing and drying device, the group It is arranged on the air outlet pipe to remove one of oxygen and a moisture of the gas.