KR101815733B1 - Method and apparatus for preparing polyamide resin - Google Patents

Abstract

A method for producing a polyamide resin of the present invention comprises: synthesizing a polyamide resin by solution polymerization in a reactor; Withdrawing a polymeric material comprising the polyamide resin and a solvent from the reactor; Supplying hot water to the discharged polymeric material; And separating the polyamide resin from the mixture by flash discharging the mixture of the polymer and the hot water. The method of producing the polyamide resin can reduce deterioration due to deterioration while increasing the degree of polymerization of the polyamide resin.

Description

METHOD AND APPARATUS FOR PREPARING POLYAMIDE RESIN BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a process for producing a polyamide resin and an apparatus for producing the same. More specifically, the present invention relates to a method and an apparatus for producing a polyamide resin capable of reducing deterioration due to deterioration while increasing the degree of polymerization of the polyamide resin.

Polyamide resins are excellent in physical properties and easy to melt-form, and are widely used for clothing materials, industrial-use fibers, engineering plastics, and the like.

As a method for producing a polyamide resin, there is known a method of polycondensing a salt or a low-order condensate formed with a conventional dicarboxylic acid and a diamine by heating under a molten condition. However, when the method is applied to a high melting point polyamide resin, the product tends to cause thermal decomposition because a high temperature is required to maintain the molten state, and the produced polyamide resin has mechanical strength, resistance to heat, There is a possibility that the physical properties of the resin are deteriorated. In addition, the polyamide resin prepared from the above-mentioned production methods has a high viscosity, including a gel, and is difficult to handle, and contents may remain on the inner wall of the reactor, resulting in a lower yield.

In order to solve the difficulty in the melt polymerization process, a solution polymerization may be used to produce a polyamide resin. The solution polymerization is a method of polymerizing a monomer in a solvent. The solvent used herein may be either one which dissolves both the monomer and the polymer, or one which dissolves only the monomer. The former is a homogeneous solution polymerization and the latter is a heterogeneous solution polymerization.

Since the nature of solution polymerization, a process of separating the solvent after polymerization is essential. Conventionally, there is a method of removing a solvent by filtration or drying of a polyamide resin after solution polymerization, but it takes a lot of steps and time and requires separate facilities and devices for separation.

As a method for removing the solvent from the polymerized product after the solution polymerization, a flash discharge method may be used in which the polymerized product under high temperature and high pressure conditions is discharged under a low temperature and a low pressure condition. In this case, however, It may deteriorate and deteriorate. In order to prevent this, it is considered that when the flash is discharged, an inert gas is supplied to prevent contact with oxygen, but there is still a limit to prevent deterioration due to high-temperature heat.

As another method for preventing deterioration of the polyamide resin, a method of lowering the polymerization temperature or increasing the content of the solvent during solution polymerization can be used. However, in both cases, there is a problem that the polymerization degree of the polyamide resin can not be prevented from being lowered.

Therefore, there is a need to develop a method and a manufacturing apparatus for a polyamide resin which can reduce the deterioration due to deterioration while easily increasing the degree of polymerization of the polyamide resin, and can easily separate the solvent.

The object of the present invention is to provide a method and an apparatus for producing a polyamide resin capable of reducing deterioration due to deterioration while increasing the degree of polymerization of the polyamide resin.

Another object of the present invention is to provide a method and apparatus for producing a polyamide resin which can reduce the amount of solvent used during solution polymerization of a polyamide resin and can easily separate a solvent after completion of polymerization.

Another object of the present invention is to provide an economical method and apparatus for producing a polyamide resin without adding additional cooling facilities and pipe making facilities.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the present invention relates to a method for producing a polyamide resin. The method comprises: synthesizing a polyamide resin by solution polymerization in a reactor; Withdrawing a polymeric material comprising the polyamide resin and a solvent from the reactor; Supplying hot water to the discharged polymeric material; And flashing out the mixture of the polymer and the hot water to separate the polyamide resin from the mixture.

In an embodiment, the solution polymerization may be carried out at a temperature of 160 to 260 DEG C and a pressure of 8 to 40 kgf / cm < ² >.

In an embodiment, the polymer may comprise 100 parts by weight of the polyamide resin and 10 to 30 parts by weight of the solvent.

In an embodiment, the solvent may comprise at least one of water, methanol and ethanol.

In an embodiment, the temperature (T1) of the polymer discharged from the reactor is 160 to 260 ° C, and the temperature of the hot water may be T1 ± 20 ° C.

In an embodiment, the flow rate of the polymerized material discharged from the reactor and the flow rate of the hot water supplied to the discharged polymerized material may be 1: 0.1 to 1: 0.9 by volume.

In an embodiment, the method may further include mixing the polymer and the hot water after supplying the hot water to the polymer.

In the embodiment, the flash discharge may be to the discharge space of the temperature and pressure conditions of 0.1 to 1.5 kgf / cm ² in the mixture is 15 to 80 ℃.

In an embodiment, the flash discharge may be to vaporize the solvent and the hot water in the mixture and solidify the polyamide resin.

In an embodiment, at the flash discharge, the method may further include supplying nitrogen for discharging the vaporized solvent and hot water.

In an embodiment, at the flash discharge, the temperature of the separated polyamide resin may be between 110 and 150 ° C.

Another aspect of the present invention relates to an apparatus for producing a polyamide resin. The apparatus comprises a reactor for solution polymerization of a polyamide resin; A discharge pipe for discharging the polymer material including the polyamide resin and the solvent from the reactor; A hot water supply unit connected to one side of the discharge pipe to supply hot water to the polymeric material discharged from the reactor; And a polymer separator connected to a lower end of the discharge pipe, for separating the polyamide resin from the mixture by flash discharge of the mixture of the polymer and the hot water.

In an embodiment, the manufacturing apparatus may further include a line mixer provided in a discharge pipe between the hot water supply unit and the polymer separator, for uniformly mixing the polymer solution and the hot water.

In embodiments, the temperature of the polymeric separator may be from 15 to 80 DEG C and the pressure may be from 0.1 to 1.5 kgf / cm < ² >.

In an embodiment, the reactor comprises one or more batch reactors, and the hot water supply may comprise a heat exchanger.

The present invention can reduce deterioration due to deterioration while increasing the degree of polymerization of a polyamide resin, reduce the amount of a solvent used in solution polymerization, easily separate a solvent after completion of polymerization, The present invention has the effect of providing an economical method of producing a polyamide resin by not adding a facility.

1 is a schematic view schematically showing a polymerization apparatus of a polyamide resin according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The method for producing a polyamide resin according to the present invention comprises: (S10) synthesizing a polyamide resin by solution polymerization in a reactor; (S20) discharging the polymerized material containing the polyamide resin and the solvent from the reactor; Supplying hot water to the discharged polymeric material (S30); And separating the polyamide resin from the mixture by flash discharging the mixture of the polymer and the hot water (S40).

In one embodiment of the present invention, step (S10) of synthesizing a polyamide resin by solution polymerization in the reactor and step (S20) of discharging the polyamide resin and the polymer-containing polymer from the reactor (S20) Solution polymerization and discharge of the resin. For example, a dicarboxylic acid component, a diamine component, a solvent, an additive (including an initiator) and the like are added to the reactor and the mixture is heated at a polymerization temperature of 160 to 260 ° C, for example, 180 to 250 ° C for 30 minutes to 6 hours Solution polymerization is carried out with stirring, and after completion of the polymerization, the polyamide resin and the polymer containing the solvent may be discharged, but the present invention is not limited thereto. Further, in solution polymerization, the polymerization pressure may be 8 to 40 kgf / cm ² , but is not limited thereto.

In an embodiment, the dicarboxylic acid component may be a dicarboxylic acid used in a polyamide resin, an alkyl ester thereof, an acid anhydride thereof, and the like, without limitation. For example, an aromatic dicarboxylic acid component may be used . The aromatic dicarboxylic acid component may include at least one aromatic dicarboxylic acid having 8 to 20 carbon atoms, for example, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7- Naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,4-phenylenedioxyphenylenic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, 4,4'-oxybis (benzoic acid) Diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 4,4'-diphenylcarboxylic acid, and mixtures thereof, but are not limited thereto .

In the specific examples, as the diamine component, a diamine used in the polyamide resin may be used without limitation, and for example, an aliphatic diamine component may be used. The aliphatic diamine component may include at least one aliphatic diamine having 4 to 20 carbon atoms, for example, 1,4-butanediamine, 1,6-hexanediamine (hexamethylenediamine), 1,7 -Heptanediamine, 1,8-octanediamine, 1,10-decanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6- hexanediamine, 1,6-hexanediamine, 5-methyl-1,9-nonanediamine, 2,2-oxybis (ethylamine), bis (3-aminopropyl) ether, ethylene glycol bis (EGBA), 1,7-diamino-3,5-dioxoheptane, mixtures thereof, and the like, but are not limited thereto.

In an embodiment, the molar ratio of the diamine component to the dicarboxylic acid component (diamine / dicarboxylic acid) may be 0.85 to 1.05, for example, 0.90 to 1.03, but not limited thereto. The reaction yield can be excellent in the above range.

In an embodiment, the polymer may include, but is not limited to, 100 parts by weight of the polyamide resin and 10 to 30 parts by weight, for example, 13 to 25 parts by weight of the solvent. Within the above range, a polyamide resin with high polymerization degree can be obtained by solution polymerization. More specifically, the polymerized product means a reaction mixture containing a polyamide resin obtained by solution polymerization and a solvent, unreacted monomers, reaction by-products and the like.

In the specific example, the solvent used may be a solvent used in the solution polymerization of a conventional polyamide resin. For example, water, methanol, ethanol, combinations thereof, and the like may be used, but the present invention is not limited thereto.

In one embodiment of the present invention, the step (S30) of supplying hot water to the discharged polymerizate reduces the decrease in polymerization degree due to excessive solvent during solution polymerization of the polyamide resin, This is a step for reducing deterioration by rapidly lowering the temperature of the solidified polyamide resin.

In an embodiment, the temperature (T1) of the polymer discharged from the reactor is 160 to 260 ° C, for example, 180 to 250 ° C .; the temperature of the hot water may vary depending on the content of the solvent in the polymer, , For example, T1 ± 10 ° C. The degree of degradation due to deterioration can be reduced while increasing the degree of polymerization of the polyamide resin within the above range.

In an embodiment, the flow rate of the polymerized polymer discharged from the reactor and the flow rate of the hot water supplied to the discharged polymerized polymer may vary depending on the temperature of the polymerized polymer and the content of the solvent in the polymerized polymer, 1: 0.9, such as 1: 0.1 to 1: 0.7. The degree of degradation due to deterioration can be reduced while increasing the degree of polymerization of the polyamide resin within the above range.

In an embodiment, the method may further include, after uniformly mixing the polymer and the hot water, supplying the hot water to the polymer, and then mixing the polymer and the hot water. For example, the mixing may be by a line mixer or the like, but is not limited thereto.

In one embodiment of the present invention, the step (S40) of separating the polyamide resin from the mixture by flash discharging the mixture of the polymer and the hot water may include vaporizing the solvent and the hot water in the mixture, The resin is solidified and separated. More specifically, in the step (S40), the mixture is discharged under a low-temperature and low-pressure condition under relatively high-temperature and high-pressure conditions, and instantaneously depressurized and depressurized to vaporize the solvent, hot water and the like in the mixture and solidify the polyamide resin Followed by separation and obtaining. Here, since the heat of vaporization required for the vaporization of the solvent and hot water is provided by the polyamide resin, the polyamide resin can be rapidly cooled by vaporization of a suitable amount of solvent and hot water, and deterioration due to deterioration can be reduced.

In embodiments, the flash emission is the mixture of 15 to 80 ℃, for example 25 to temperature, and 0.1 to 1.5 kgf / cm ² for 60 ℃, for example 0.2 to 1, the space pressure conditions kgf / cm ² ( Polymer separator). The solvent and hot water can be easily removed from the mixture containing the polyamide resin, the solvent, the hot water and the like within the above range, and the solidified polyamide resin can be separated.

In an embodiment, the method may further comprise supplying nitrogen for the discharge of the vaporized solvent and hot water upon flash discharge.

In embodiments, at the flash discharge, the temperature of the separated polyamide resin may be between 110 and 155 ° C, for example between 115 and 150 ° C. The temperature of the polyamide resin can be lowered to 60 ° C or lower only by natural cooling before the deterioration of the polyamide resin occurs in the above range.

1 is a schematic view schematically showing a polymerization apparatus of a polyamide resin according to an embodiment of the present invention. As shown in FIG. 1, a polymerization apparatus for a polyamide resin according to an embodiment of the present invention includes a reactor 10 in which a solution polymerization of a polyamide resin is performed; A discharge pipe (20) for discharging the polymerized material containing the polyamide resin and the solvent from the reactor (10); A hot water supply unit 30 connected to one side of the discharge pipe 20 for supplying hot water to the polymer discharged from the reactor 10; And a polymerizer separator 40 connected to a lower end of the discharge pipe 20 for separating the polyamide resin from the mixture by flash discharge of the mixture of the polymerizer and the hot water.

In an embodiment, the reactor 10 may employ one or more conventional batch reactors. For example, two or more reactors may be connected in series or parallel to continuously discharge the polymeric material including the polyamide resin and the solvent, but the present invention is not limited thereto.

In embodiments, the discharged polymerizate may be transferred to the polymerizer separator 40 via a conventional discharge pipe 20. Hot water produced in the hot water supply part 30 during the transfer of the polymer can be mixed into one side of the discharge pipe 20 to form the mixture.

In an embodiment, the hot water supply unit 30 may include a heat exchanger 32 capable of controlling the temperature of the hot water. 1, the heat exchanger 32 is shown separately from the hot water supply unit 30. However, the heat exchanger 32 may be integrally formed with the hot water supply unit 30. [

As described above, the volume ratio of the flow rate of the polymerized material discharged from the reactor 10 and the flow rate of the hot water supplied to the discharged polymerized material (polymeric material: hot water) is in the range of 1: 0.1 to 1: 0.9, (Not shown), which can detect and control the flow rate of the polymerizate and the flow rate of the hot water, in order to adjust the flow rate of the polymerizate to 0.1 to 1: 0.7.

The manufacturing apparatus further includes a line mixer 50 provided in the discharge pipe 20 between the hot water supply unit 30 and the polymerizer separator 40 for uniformly mixing the polymer solution and the hot water can do.

In an embodiment, the polymeric separator 40 is a space for separating the polyamide resin from the mixture by flash-discharging the mixture. As described above, the polymerizer separator 40 can be formed at a temperature of 15 to 80 캜, for example, 25 to 60 캜, May be 0.1 to 1.5 kgf / cm ² , for example, 0.2 to 1 kgf / cm ² . Since the reactor 10 and the discharge pipe 20 are relatively hot and pressurized as compared with the polymerizer separator 40, the solvent and hot water of the flash-discharged mixture are rapidly vaporized, and the polyamide resin in which the solvent and hot water are removed is solidified .

In the embodiment, the vaporized hot water and the solvent may be discharged to the outside through the upper piping 42 of the polymerizer separator 40, and the solidified polyamide resin may be discharged through the lower piping 44 of the polymer separator 40 .

In an embodiment, an inert gas such as nitrogen may be supplied through the injection port 46 provided at one side of the polymerizer separator 40 for smooth removal of the vaporized solvent and hot water.

As described above, the apparatus for producing a polyamide resin according to an embodiment of the present invention reduces the decrease in degree of polymerization due to an excessive amount of solvent during solution polymerization of the polyamide resin, and reduces the temperature of the solidified polyamide resin after the flash discharge Since the deterioration can be reduced by supplying the hot water to the polymerizer separator 40 at a rapid rate and the hot water is supplied from the discharge pipe 20 through which the polymerized material discharged from the reactor 10 is transferred to the polymerizer separator 40, It is possible to reduce the degradation of the polyamide resin in the polymerized polyamide resin in which the target degree of polymerization has been achieved or the degradation of the degree of polymerization due to the reverse reaction, side reaction or the like.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Example

Example 1

Using the apparatus for producing a polyamide resin of Fig. 1, a polyamide resin was produced. In the reactor 10, a polymer solution at 230 DEG C containing 13 wt% of a solvent (water) and 87 wt% of a polyamide resin was subjected to solution polymerization to a polymerizer separator 40 through a discharge pipe 20 at a flow rate of 12.5 kg / . The hot water preheated to 230 deg. C in the hot water supply unit 30 was supplied to the discharge pipe 20 by controlling the flow rate so that the volume ratio of the polymerizer: hot water was 1: 0.2. After the polymer and hot water were uniformly mixed in the line mixer 50, the mixture was discharged by flash in the polymerizer separator 40. The temperature and intrinsic viscosity (IV) of the solidified polyamide resin were measured immediately after the flash discharge The results are shown in Table 1 below.

Example 2

The flash was discharged in the same manner as in Example 1 except that the volume ratio of the polymeric material: hot water was adjusted to be 1: 0.3. The temperature and the intrinsic viscosity (IV) of the solidified polyamide resin were measured The results are shown in Table 1 below.

Example 3

The flash was discharged in the same manner as in Example 1, except that the temperature of the polymer was 240 ° C, the temperature of the hot water supplied was 240 ° C, and the flow rate was adjusted so that the volume ratio of polymeric material: hot water was 1: 0.3. The temperature and intrinsic viscosity (IV) of the solidified polyamide resin immediately after discharge were measured and are shown in Table 1 below.

Example 4

The flash was discharged in the same manner as in Example 1, except that the temperature of the polymer was 240 ° C., the temperature of the hot water supplied was 240 ° C., and the flow rate was adjusted so that the volume ratio of the polymeric material: hot water was 1: 0.4. The temperature and intrinsic viscosity (IV) of the solidified polyamide resin immediately after discharge were measured and are shown in Table 1 below.

Example 5

The flash was discharged in the same manner as in Example 1, except that the temperature of the polymer was 250 ° C., the temperature of the hot water supplied was 250 ° C., and the flow rate was adjusted so that the volume ratio of the polymer: hot water was 1: 0.5 , The temperature and intrinsic viscosity (IV) of the solidified polyamide resin immediately after the flash discharge were measured and are shown in Table 1 below.

Example 6

The flash was discharged in the same manner as in Example 1, except that the temperature of the polymer was 250 ° C, the temperature of the hot water supplied was 250 ° C, and the flow rate was adjusted so that the volume ratio of the polymeric material: hot water was 1: 0.6. The temperature and intrinsic viscosity (IV) of the solidified polyamide resin immediately after discharge were measured and are shown in Table 1 below.

How to measure property

(1) Temperature (unit: ° C) of solidified polyamide resin immediately after flash discharge: Measured in real time using a temperature sensor (thermometer) in a polymer separator (flasher).

(2) Intrinsic viscosity (IV, unit: dL / g) of solidified polyamide resin immediately after flash discharge: 0.2 g of solidified polyamide resin was dissolved in concentrated sulfuric acid (98%) at a concentration of 0.5 g / dL , And then measured using a Ubbelodhde viscometer at 25 ° C.)

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Polymerization temperature 230 ℃ 230 ℃ 240 ℃ 240 ℃ 250 ℃ 250 ℃ Hot water temperature 230 ℃ 230 ℃ 240 ℃ 240 ℃ 250 ℃ 250 ℃ Polymer: Hydrothermal volume ratio 1: 0.2 1: 0.3 1: 0.3 1: 0.4 1: 0.5 1: 0.6 Immediately after flash discharge polyamide resin Temperature 143 ° C 116 ° C 149 ℃ 127 ℃ 149 ℃ 131 ° C IV (dL / g) 0.11 0.11 0.13 0.13 0.15 0.15

It can be seen from the results of Table 1 that the polyamide resin manufacturing method of the present invention (Examples 1 to 6) is such that hot water is supplied to the polymerizate and the intrinsic viscosity (IV) value (degree of polymerization) And the temperature of the polyamide resin is lowered to 116 to 149 占 폚 due to the heating water and the vaporization of the solvent, so that deterioration due to deterioration can be reduced.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (15)

Synthesizing a polyamide resin by solution polymerization in a reactor;
Withdrawing a polymeric material comprising the polyamide resin and a solvent from the reactor;
Supplying hot water to the discharged polymeric material; And
Separating the polyamide resin from the mixture by flash discharge of the mixture of the polymer and the hot water,
Wherein the flash discharge vaporizes the solvent and the hot water in the mixture to solidify the polyamide resin and the temperature T1 of the polymer discharged from the reactor is 160 to 260 ° C and the temperature of the hot water is T1 ± 20 ° C., and the flow rate of the polymerized material discharged from the reactor and the flow rate of the hot water supplied to the discharged polymerized material are 1: 0.1 to 1: 0.9 by volume.
The method according to claim 1, wherein the solution polymerization is carried out at a temperature of 160 to 260 DEG C and a pressure of 8 to 40 kgf / cm < ² >.
The method for producing a polyamide resin according to claim 1, wherein the polymer comprises 100 parts by weight of the polyamide resin and 10 to 30 parts by weight of the solvent.
The method for producing a polyamide resin according to claim 1, wherein the solvent comprises at least one of water, methanol and ethanol.
delete delete The method for producing a polyamide resin according to claim 1, wherein the method further comprises mixing the polymer and the hot water after supplying the hot water to the polymer.
The method for producing a polyamide resin according to claim 1, wherein the flash discharge discharges the mixture to a space at a temperature of 15 to 80 캜 and a pressure of 0.1 to 1.5 kgf / cm ² .
delete The method of manufacturing a polyamide resin according to claim 1, further comprising the step of supplying nitrogen for discharging the evaporated solvent and hot water at the time of flash discharge.
The method of claim 1, wherein the temperature of the separated polyamide resin during the flash discharge is 110 to 150 ° C.
A reactor in which the solution polymerization of the polyamide resin is carried out;
A discharge pipe for discharging the polymer material including the polyamide resin and the solvent from the reactor;
A hot water supply unit connected to one side of the discharge pipe to supply hot water to the polymeric material discharged from the reactor; And
And a polymerizer separator connected to a lower end of the discharge pipe, for separating the polyamide resin from the mixture by flash discharge of the mixture of the polymerizer and the hot water,
Wherein the flash discharge vaporizes the solvent and the hot water in the mixture to solidify the polyamide resin and the temperature T1 of the polymer discharged from the reactor is 160 to 260 ° C and the temperature of the hot water is T1 ± 20 ° C., and the flow rate of the polymerized material discharged from the reactor and the flow rate of the hot water supplied to the discharged polymerized material are 1: 0.1 to 1: 0.9 by volume.
The manufacturing method of a polyamide resin according to claim 12, wherein the manufacturing apparatus further comprises a line mixer provided in a discharge pipe between the hot water supply unit and the polymer separator, for uniformly mixing the polymer solution and the hot water. Device.
13. The apparatus for producing a polyamide resin according to claim 12, wherein the polymerizer separator has a temperature of 15 to 80 DEG C and a pressure of 0.1 to 1.5 kgf / cm < ² >.
13. The apparatus of claim 12, wherein the reactor comprises at least one batch reactor, and wherein the hot water supply comprises a heat exchanger.

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