JP2001200053A - Preparation method of polyamide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method in which a mixture of a diamine component and a dicarboxylic acid component which have a regulated balance between the moles of the two components is supplied to a polymerization reactor to suitably prepare a polyamide by using a batch mass weighting method which ensures regulation of the mole balance between the diamine component and the dicarboxylic acid component to be arranged without using a nylon salt and its aqueous solution as supplying materials to a polymerization reactor. SOLUTION: This preparation method of a polyamide comprises polymerization of a xylylene diamine and a dicarboxylic acid component, wherein the diamine component is weighed and supplied to a batch regulating tank and the dicarboxylic component is weighed and added while the liquid diamine component is stirred in the batch regulating tank to achieve a desired mole balance and the resulting slurry solution is provided as a supplying material for polyamide preparation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing polyamide. More specifically, in a batch-type adjustment tank, a dicarboxylic acid component is added to a diamine component mainly composed of xylylenediamine to prepare a slurry solution in which substantially no amidation reaction has occurred, and the slurry solution is supplied when producing a polyamide. The present invention relates to a method for producing a polyamide as a raw material.

[0002]

2. Description of the Related Art In the production of a polyamide synthesized from a diamine component and a dicarboxylic acid component, it is very important to control the molar balance between the diamine component and the dicarboxylic acid component in order to achieve a predetermined degree of polymerization. In order to obtain a polyamide having a predetermined molar balance, attention must be paid to the accuracy of charging the diamine component and the dicarboxylic acid component, which are raw materials, and to preventing the diamine component from distilling out during the reaction. In the case of a nylon salt or an aqueous solution thereof, which is a general feedstock for producing a polyamide, the accuracy of preparation of the polyamide component is guaranteed by pH adjustment, but this is caused by using a nylon salt or an aqueous solution thereof as a feedstock. There is a problem.

When an aqueous solution of a nylon salt is used as a feedstock, in a batch polymerization, the aqueous solution of a nylon salt is heated under pressure in a single reaction tank, and polymerization is promoted in a uniform phase while distilling off the diamine component. After the immobilization, the pressure of the steam in the system is gradually released, and finally the pressure is reduced to normal pressure or reduced pressure to complete the polymerization. On the other hand, continuous polymerization usually comprises two to three steps depending on the degree of polymerization. The first step is a step of supplying an aqueous solution of a nylon salt to advance the polymerization to the prepolymer. In the second and subsequent steps, water and the prepolymer are separated, and the degree of polymerization of the prepolymer is further increased to achieve a predetermined degree of polymerization. . The continuous polymerization has many industrially advantageous aspects as compared with the batch polymerization, and is disclosed in JP-B-44-22510 and JP-B-49-2.
0640 gazette, JP-B-56-46487, JP-B-5
-52333 discloses many techniques.

In both batch and continuous polymerizations, an aqueous solution of about 50% nylon salt is generally used as a feedstock, but a high pressure vessel is required to prevent the distilling out of water as a solvent at the beginning of polymerization. Finally, it is necessary to remove a large amount of water and condensed water as a solvent, and at this time, it is necessary to take measures to avoid various inconveniences such as foaming and solidification of the polymer due to latent heat of vaporization of water. Also, it requires a lot of heat energy to remove a large amount of water,
There are many technical and economic issues. On the other hand, when a nylon salt is used as a raw material, waste of heat energy for removing a large amount of water can be avoided, but a process for isolating and purifying the nylon salt is required, and it is hardly an efficient method.

A polymerization method in which a nylon salt and an aqueous solution of a nylon salt are not used as a feedstock is disclosed in JP-A-10-509760.
It is disclosed in the gazette. In this method, a dicarboxylic acid component or a dicarboxylic acid excess component in a molten state is supplied to a multistage reactor, and a gas or liquid diami component is supplied in the second and subsequent stages, and the molar balance is fed back using a near infrared spectrometer. It is controlled by the system. Unlike nylon salts and aqueous solutions of nylon salts, when the monomer components are continuously and separately supplied to the polymerization vessel, charging accuracy is an issue, and a flow pump or the like has a sufficient molar balance to control the degree of polymerization of the polyamide. It is difficult to achieve control accuracy. Therefore, it is necessary to detect and correct the molar balance during the polymerization step.

[0006] In addition to nylon salt and an aqueous solution of nylon salt, the most advantageous method for controlling the molar balance of the preparation of the polyamide component is to separate the diamine component and the dicarboxylic acid component separately using a mass meter such as a load cell. This is a method in which the mass is measured in a batch system and then supplied to the reaction system. For example, a dicarboxylic acid component in a molten state is weighed using a mass meter and supplied to the polymerization tank, and then the diamine component is supplied to the reaction system while weighing the diamine storage tank using a mass meter, and the molar balance is obtained. Can be adjusted. This method can be suitably used for carrying out polymerization under normal pressure without using a nylon salt as disclosed in JP-A-58-111829. However, when the diamine component is mixed at a temperature equal to or higher than the melting point of the dicarboxylic acid, the amidation reaction proceeds remarkably, and thus the mixture (reactant) of the dicarboxylic acid component and the diamine component adjusted by this method has already been polymerized, It cannot be a stable raw material for feeding to another polyamide polymerization vessel.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for preparing a molar balance of a dian component and a dicarboxylic acid component without using a nylon salt or an aqueous solution thereof as a feedstock to a polymerization vessel (hereinafter simply referred to as "charged moles"). Using a batch mass weighing method that can reliably control the "balance"), a mixture of a diamine component and a dicarboxylic acid component, in which the amidation reaction has not substantially occurred and whose molar balance has been adjusted, is polymerized. And a method for suitably producing a polyamide.

[0008]

The present inventors have made intensive studies and found that a mixture comprising a diamine component and a dicarboxylic acid component containing xylylenediamine in an amount of 80 mol% or more was converted to a specific temperature and a specific water concentration in the absence of a solvent. The present inventors have found that a slurry in an extremely stable and uniform state where no amidation reaction occurs does not occur, and has completed the present invention.

That is, the present invention relates to a method for producing a polyamide obtained by polymerizing a diamine component containing at least 80 mol% of xylylenediamine and a dicarboxylic acid component. While stirring the liquid diamine component in the batch-type adjustment tank,
The weight of the dicarboxylic acid component is measured and added so that the desired molar balance is achieved, and the slurry is then added to prepare a slurry solution comprising a diamine and a dicarboxylic acid in which substantially no amidation reaction has occurred. The present invention relates to a method for producing a polyamide, which is used as a raw material for production.

The polyamide component used in the present invention comprises 8
0 mol% or more is a diamine component and a dicarboxylic acid component which are xylylenediamine. Examples of xylylenediamine include meta, para and ortho-xylylenediamine,
The mixing ratio is arbitrarily selected. The reason why xylylenediamine can be suitably used in the present invention is that the boiling point is higher than the polyamide melting point. In order to obtain a polyamide having a predetermined molar balance, it is a matter of course to improve the charging accuracy of the diamine component and the dicarboxylic acid component as raw materials and to fix the diamine component during polymerization. Having a melting point higher than the melting point is extremely advantageous in fixing the diamine and controlling the molar balance.

Examples of the diamine component other than xylylenediamine include tetramethylenediamine, hexamethylenediamine, and 1-3-bisaminomethylcyclohexane. Examples of the dicarboxylic acid component include adipic acid, succinic acid, sebacic acid, dodecanedioic acid, isophthalic acid, terephthalic acid, and 2-6-naphthalenedicarboxylic acid. These dicarboxylic acids can be used alone or in combination of two or more. Considering practical properties of the obtained polyamide, a dicarboxylic acid component in which 50% by mole or more is adipic acid can be suitably used. Examples of the polyamide component other than the diamine component and the dicarboxylic acid component include lactams such as caprolactam, valerolactam, laurolactam, and undecalactam, and aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. The slurry can be used in a timely manner within a range that does not hinder the preparation of a slurry solution in which substantially no amidation reaction, which is the most important feature of the present invention, is prepared.

The molar balance of the polyamide after the completion of the polymerization reaction (hereinafter sometimes referred to simply as “polyamide molar balance”) may be arbitrarily selected from excess diamine components, excess dicarboxylic acid components and equimolar amounts. In general, in order to achieve a desired molar balance of the polyamide, the molar balance of the raw materials for the polyamide is determined by mixing the diamine component in an amount corresponding to the diamine component distilled out of the reaction system together with the condensed water generated by the amidation reaction. It is preferable to set excessively. When measuring the mass of the diamine component and the dicarboxylic acid component in the present invention, a load cell, a mass measuring instrument such as a balance can be suitably used, and the diamine component and the dicarboxylic acid component are stored in a measuring tank in which the mass measuring instrument is installed. And a method in which a predetermined amount of a diamine component and a dicarboxylic acid component are supplied to a batch-type adjusting tank while measuring the mass of the measuring tank.

When and after the addition of the dicarboxylic acid component to the liquid diamine component in the batch-type adjustment tank, it is preferable to maintain the temperature of the diamine component and the slurry solution at a temperature not lower than the freezing point of the diamine component and not higher than 80 ° C. When the temperature is below the freezing point of the diamine component, uniform stirring and mixing in the system is difficult, and this is not preferable in supplying the slurry solution to the polymerization vessel. When the temperature of the diamine component and the slurry solution exceeds 80 ° C., the reaction for forming a nylon salt becomes remarkable, heat of neutralization accumulates, the temperature in the system rises sharply, and the reaction for forming a nylon salt is further accelerated. Further, since the nylon salt is not a slurry solution but is in a granular form, uniform stirring and mixing in the system is hindered. The amidation reaction starts due to such rapid temperature rise and local overheating, and condensed water is released into the system. The formation reaction of the nylon salt since water acts catalytically, resulting in generation and amidation reaction of nylon salt proceeds without endlessly. Naturally, sufficient heat is not applied to bring the polyamide into a uniform liquid phase, so that the system becomes massive and uniform stirring and mixing is completely impossible.

In order to obtain a uniform and stable slurry composed of a diamine component and a dicarboxylic acid component in which substantially no amidation reaction has occurred, a dicarboxylic acid component is added to the diamine component in a liquid state in a batch type adjusting tank. When and after addition,
There is no need to intentionally add a solvent, and the present invention can be carried out in the absence of a solvent. The water concentration in the slurry solution prepared in the batch-type adjustment tank is preferably 0.7% by mass (the mass% of water based on the slurry solution; the same applies hereinafter), and more preferably 0% or less. 0.5% by mass or less. When the water concentration exceeds 0.7% by mass, water acts as a catalyst for the nylon salt formation reaction. Therefore, even when the temperature of the diamine component and the slurry is 80 ° C. or lower, the nylon salt formation reaction becomes remarkable. The heat of neutralization accumulates, and the temperature in the system rises sharply, further accelerating the nylon salt formation reaction. Therefore amidation reaction begins as described above, water of condensation is the generation and amidation reactions of nylon salt is released into the system proceeds without endlessly. Naturally, sufficient heat is not applied to bring the polyamide into a uniform liquid phase, so that the system becomes massive and uniform stirring and mixing is completely impossible.

The diamine component supplied to the batch type adjusting tank may be liquid or solid, but the temperature of the diamine component is not lower than the freezing point and not higher than 80 ° C. for handling and the same reason as described above. Are preferred. Also, for the same reason as above, it is desirable that the water concentration is low, but since diamine is usually purified by distillation,
If it is a general industrial product, the water concentration is sufficiently usable in the present invention, and it is not necessary to add a special dehydration operation. The mass of such a diamine component is measured to a predetermined amount by a mass measuring instrument and supplied to a batch-type adjusting tank. This operation is desirably performed in an inert gas such as nitrogen. The dicarboxylic acid component supplied to the batch-type adjusting tank may be liquid or solid, but the temperature of the dicarboxylic acid component is preferably 80 ° C. or lower for the same reason as described above. For the same reason as above, it is desirable that the water concentration is low, but if it is a normal industrial product, the water concentration is 0.1 to 0.2% by weight, and it can be sufficiently used in the present invention. The mass of such a dicarboxylic acid component is measured to a predetermined amount by a mass measuring instrument and supplied to a batch-type adjusting tank. This operation is desirably performed in an inert gas such as nitrogen.

The batch-type adjusting tank used in the present invention is not particularly limited as long as it has a stirring ability and a stirring power capable of adjusting a uniform slurry solution. Further, in order to avoid oxidation of the polyamide, it is desirable that the inside of the system be replaced with an inert gas such as nitrogen for the purpose of minimizing oxygen in the slurry solution. When supplying a slurry solution prepared in a batch-type adjustment tank to a polyamide polymerization vessel as a feedstock when producing polyamide, continuous supply is possible by installing two or more batch-type adjustment tanks and using them alternately. Becomes In other words, even when the slurry solution is supplied to the continuous polymerization vessel and the continuous production method of the polyamide is carried out, the slurry solution in the batch-type adjustment tank is uniform and stable without substantially causing the amidation reaction. Since it is a slurry solution and does not show any property change with the residence time, the process can be easily shifted from a batch-type slurry solution adjusting step, that is, a molar balance adjusting step, to a continuous-type polymerization step.

When the slurry solution obtained in the present invention is supplied to a continuous polyamide polymerization reactor, the continuous polymerization reactor to which the slurry solution is supplied is kept outside in order to maintain the molar balance achieved in the slurry adjusting step. It is particularly important that the structure be such that no gas phase component is distilled off and intimate mixing of the gas-liquid phase is achieved. For this reason, it is desirable that the inside of the system be kept at a pressure from normal pressure to a pressurized state, and if necessary, a device such as a gear pump be installed at a supply port and / or a discharge port of the continuous polymerization vessel to form a seal structure. Further, it is necessary that the temperature of the supplied slurry solution can be sequentially raised in the flow direction to a temperature equal to or higher than the melting point of the obtained polyamide. For this purpose, in particular, a horizontal twin-screw mixer can be suitably used.

In order to obtain a polyamide having a uniform degree of polymerization, it is important to keep the residence time in a continuous polymerization vessel constant. The polymerization vessel for supplying the slurry solution is a polymerization vessel having plug flow properties. It is desirable. After the diamine component is immobilized in the polyamide, for the purpose of increasing the degree of polymerization of the polyamide to a predetermined value, the pressure in the system is gradually lowered, and a polymerization having a structure capable of positively distilling condensation water out of the system. It is desirable to use a continuous polymerization vessel having an exhaust port such as a vent.

When the slurry solution obtained in the present invention is fed to a batch polymerization vessel, it is desirable to use the slurry solution from normal pressure to a pressurized system in order to maintain the molar balance achieved in the slurry solution adjusting step. Since the boiling point of xylylenediamine is higher than the melting point of the polymer, the pressure can be set considerably lower than in the case where an aqueous solution of a nylon salt is used as a raw material. In the batch system, it is advantageous to quickly raise the temperature of the slurry solution to the polyamide melting point, and the L / L with multi-stage stirring blades having a large heat transfer area is advantageous.
The use of a horizontal reactor with a large D is preferred. When a polymerization vessel having a reactor shape is used, the method can be suitably carried out by gradually adding a slurry solution to the reaction system while maintaining the reaction system at a temperature equal to or higher than the melting point of the polyamide.

Further, as described above, water catalyzes the reaction of forming a nylon salt in the slurry solution, so that a large amount of heat of neutralization is generated, and further, the amidation reaction is promoted. Addition of a small amount of water as a catalyst is also very advantageous in promoting the reaction. Although the amount of water to be added is not particularly limited, it is desirable that the amount of water is 0.3% by mass or more and 10% by mass or less in the slurry solution. At less than 0.3% by mass, the effect is not so much recognized,
If it exceeds 10% by mass, the gas phase in the polymerization vessel increases, which is not only disadvantageous for immobilization of the diamine, but also undesirably causes separation and solidification of the polyamide when separating the polyamide and condensed water.

[0021]

The following effects can be obtained by the method for producing a polyamide according to the present invention. (A) Since an aqueous solution of a nylon salt is not used as a feedstock for the polymerization reactor, there is no need to use a polymerization reactor with a high pressure specification. (B) Since an aqueous solution of a nylon salt is not used as a raw material, foaming and solidification of the polyamide when a large amount of water is removed can be avoided, and there is no energy loss for removing water as a solvent. (C) Since the charging of the diamine component and the dicarboxylic acid component, which are the raw materials, can be reliably controlled by using a batch-type mass measuring method, the accuracy of controlling the molar balance in the charging is improved.

[0022]

The present invention will be specifically described below with reference to examples and comparative examples. In addition, the measurement for evaluation in this invention was based on the following method. (A) Terminal amino group concentration The polyamide was precisely weighed, and phenol / ethanol = 4/1.
The solution was stirred and dissolved in the volume solution at 20 to 30 ° C. After complete dissolution, the content was determined by neutralization titration with a 0.1 mol / liter (hereinafter, liter is referred to as "L") aqueous hydrochloric acid solution while stirring. (B) Terminal carboxyl group concentration The polyamide was precisely weighed and dissolved in benzyl alcohol with stirring at 160 to 180 ° C under a nitrogen stream. After complete dissolution,
The solution was cooled to 80 ° C. or lower under a nitrogen stream, 10 cc of methanol was added with stirring, and neutralization titration was performed with a 0.1 mol / L aqueous sodium hydroxide solution.

(C) Number average molecular weight The number average molecular weight was determined from the concentration of terminal amino groups and the concentration of terminal carboxyl groups by the following formula. Number average molecular weight = 2 × 10 ⁶ / ([NH] + [COO
H]) ([NH ₂ ] is the terminal amino group concentration (μeq / g), [CO
OH] represents the terminal carboxyl group concentration (μeq / g). (D) Moisture concentration (% by mass) The moisture concentration was determined using a Karl Fischer trace moisture meter (CA-05) manufactured by Mitsubishi Chemical Corporation.

Examples 1-2, Comparative Example 1 546.44 g (4 mol) of metaxylylenediamine (purity: 99.70% by mass) was placed in a 2 L stainless steel container.
After stirring, the mixture was stirred while flowing nitrogen, and heated in an oil bath to raise the temperature of the system to a predetermined temperature. Adipic acid (purity: 99.85% by mass, water content: 0.15% by mass) was weighed, and then added to a stainless steel container for 3 minutes after weighing 585.44 g (4 mol) to change the set temperature of the oil bath. Without immersing, a stainless steel container was stirred while being immersed, and the condition in the system was observed. Two minutes after the completion of the addition of adipic acid, a small amount was sampled, and the water concentration of the slurry solution was measured. Table 1 shows the results.

Table 1 Example 1 Example 2 Comparative Example 1 Temperature (° C.) 22 80 90 Moisture concentration (% by mass) 0.35 0.34 0.34 Situation 2 minutes after completion of addition of adipic acid System temperature (° C.) ) 34 75 170 Stirring situation Good Good Impossible Situation in the system Slurry solution Slurry solution Lumpy Condensation water generated No No Yes 10 minutes after completion of adipic acid addition System temperature (° C) 35 81-Stirring condition Good Good- Situation in the system Slurry solution Slurry solution-Generation of condensed water None None-30 minutes after completion of adipic acid addition System temperature (° C) 5780-Stirring condition Good Good-System condition Slurry solution Slurry solution-Condensation Water generation None None-120 minutes after completion of adipic acid addition System temperature (° C) 42 80-Stirring condition Good Good-System condition Slurry solution slurry Lee solution- Condensation water generation None None-

As is apparent from Table 1, when meta-xylylenediamine and adipic acid are mixed at a temperature exceeding 80 ° C.,
A sharp rise in the temperature in the system due to the heat of neutralization accompanying the nylon salt formation reaction is observed, and the amidation reaction proceeds to generate condensed water. In addition, stirring becomes extremely difficult, and the inside of the system becomes clumpy, and a uniform phase cannot be maintained. On the other hand, when meta-xylylenediamine and adipic acid were mixed at a temperature of 80 ° C. or less, the temperature in the system was maintained at a temperature of 80 ° C. or less.

Examples 3-4, Comparative Examples 2-3 546.44 g (4 mol) of metaxylylenediamine (purity: 99.70% by mass) in a 2-L stainless steel container.
After weighing, the mixture was charged with a predetermined amount of water, stirred while flowing nitrogen, and heated in an oil bath to raise the temperature of the system to a predetermined temperature. Adipic acid (purity: 99.85% by mass, water content: 0.15% by mass) was weighed, and then added to a stainless steel container for 3 minutes after weighing 585.44 g (4 mol) to change the set temperature of the oil bath. Without immersion, the container was stirred while being immersed, and the state in the system was observed. In addition, a small amount was sampled 2 minutes after the addition of adipic acid, and the water concentration of the slurry solution was measured. Table 2 shows the results.

Table 2 Example 3 Comparative Example 2 Example 4 Comparative Example 3 Temperature (° C.) 40 40 80 80 Moisture concentration (% by mass) 0.63 0.74 0.51 0.72 2 minutes after completion of adipic acid addition Situation of the system Temperature (° C) 66 68 75 179 Stirring condition Good Good Good Impossible Situation of the system Slurry solution Slurry solution Slurry solution Lumpy Condensation water generated No None None Yes 10 minutes after completion of adipic acid addition Temperature (° C) 66 16880-Stirring condition Good Impossible Good-Condition in system Slurry solution Lumpy slurry solution-Generation of condensed water No Yes No-30 minutes after completion of adipic acid addition System temperature (° C) 64 8080 − Stirring condition Good Good − System condition Slurry solution Slurry solution − Condensation water generation None None −

As is clear from Table 2, when mixing meta-xylylenediamine and adipic acid, even if the temperature is below 80 ° C., if the water content in the system exceeds 0.7% by mass, the temperature in the system rises sharply. And generation of condensed water is observed. In addition, stirring becomes extremely difficult, and the inside of the system becomes clumpy, and a uniform phase cannot be maintained.

Example 5 A 200 g slurry of metaxylylenediamine and adipic acid obtained according to the present invention was kept at 250 ° C. at a rate of 5 g / min. It was supplied to the polymerization tank under normal pressure. 260 after the end of supply
Temperature to 30 ° C over 30 minutes, and
The pressure was reduced to a and kept for 20 minutes. Table 3 shows the molar balance and the number average molecular weight obtained from the terminal group concentration of the obtained polyamide.

Example 6 Metaxylylenediamine / paraxylylenediamine / adipic acid / terephthalic acid obtained according to the present invention = 55 /
Slurry solution 20 consisting of 45/85/15 (mol%)
Example 5 in which 0 g was maintained at 270 ° C. at a speed of 5 g / min.
Was supplied under normal pressure to the polymerization tank used in step (1). 270 ° C after completion of supply
At 270 ° C., and further reduced to 80 KPa at 270 ° C. for 20 minutes. Table 3 shows the molar balance and the number average molecular weight obtained from the terminal group concentration of the obtained polyamide. It was confirmed that the polymerization of the reaction product using the slurry solution obtained by the present invention as a feed material was progressing, and the molar balance of the slurry solution (diamine component / dicarboxylic acid component molar ratio: 1.000) was determined. Almost achieved.

Table 3 Example 5 Example 6 Molar balance ^* 0.992 0.990 Number average molecular weight 14210 13550 * 1: Diamine component / dicarboxylic acid component

Claims (11)

[Claims] 1. A method for producing a polyamide obtained by polymerizing a diamine component containing at least 80 mol% of xylylenediamine and a dicarboxylic acid component, wherein the mass of the diamine component is measured and then supplied to a batch-type adjusting tank. While stirring the liquid diamine component in the batch-type adjustment tank, the mass of the dicarboxylic acid component was measured and added so as to achieve a desired molar balance, and the mixture was substantially amidated. A method for producing polyamide, comprising preparing a slurry solution comprising a diamine and a dicarboxylic acid, and using the slurry solution as a feedstock for producing polyamide. 2. The method for producing a polyamide according to claim 1, wherein the weight of the diamine component and the dicarboxylic acid component is measured using a measuring tank provided with a mass measuring device. 3. The temperature of the diamine component and the slurry solution is maintained at a temperature not lower than the freezing point of the diamine component and not higher than 80 ° C. when and after the dicarboxylic acid component is added to the liquid diamine component in the batch-type adjusting tank. The method for producing a polyamide according to claim 1 or 2, wherein: 4. The method for producing a polyamide according to claim 1, wherein the water concentration in the slurry solution prepared in the batch-type adjustment tank is 0.7% by mass or less. 5. When and after the addition of the dicarboxylic acid component to the liquid diamine component in the batch-type adjusting tank, the diamine component and the slurry solution are kept at a temperature not lower than the freezing point of the diamine component and not higher than 80 ° C. The method for producing a polyamide according to claim 1, wherein the water concentration in the solution is maintained at 0.7% by mass or less. 6. A method for setting a molar balance between a diamine component and a dicarboxylic acid component supplied to a batch-type adjusting tank,
The method for producing a polyamide according to any one of claims 1 to 5, wherein the diamine component is supplied in an excess amount corresponding to the diamine component distilled out of the reaction system together with the condensed water generated by the amidation reaction. 7. The method according to claim 1, wherein at least 50 mol% of xylylenediamine is meta-xylylenediamine and at least 50 mol% of dicarboxylic acid is adipic acid.
7. The method for producing a polyamide according to any one of items 1 to 6. 8. A method in which two or more batch-type adjustment tanks are alternately used,
The method for producing a polyamide according to any one of claims 1 to 7, wherein a slurry solution comprising a diamine component and a dicarboxylic acid component is continuously supplied to a polymerization vessel as a raw material for producing the polyamide. 9. The process for producing a polyamide according to claim 1, wherein a slurry solution comprising a diamine component and a dicarboxylic acid component is supplied to a continuous polymerization vessel as a feedstock for producing the polyamide. Method. 10. The process for producing a polyamide according to claim 1, wherein a slurry solution comprising a diamine component and a dicarboxylic acid component is supplied to a batch polymerization reactor as a feedstock for producing the polyamide. . 11. The polyamide according to claim 9, wherein 0.3% by weight or more and 10% by weight or less of water are supplied to a polyamide polymerization vessel together with a slurry solution comprising a diamine component and a dicarboxylic acid component. Manufacturing method.