JP5141331B2 - Manufacturing method of polyamide resin - Google Patents

Description

  The present invention relates to a method for producing a polyamide resin. In detail, it is related with the manufacturing method of the polyamide resin whose dicarboxylic acid component is oxalic acid.

  A polyamide resin in which the dicarboxylic acid component is oxalic acid is called a polyoxamide resin, and is known to have a higher melting point and a lower saturated water absorption rate than other polyamide resins having the same amino group concentration (Patent Document 1).

  So far, polyoxamide resins using various diamines as diamine components have been proposed. The polyoxamide resin is obtained by polycondensation of oxalic acid or an oxalic acid diester and an aliphatic or aromatic diamine. However, when oxalic acid is used as a monomer, a synthesis example in which a high molecular weight polyoxamide resin is obtained because oxalic acid itself thermally decomposes when it exceeds 180 ° C., and the oxalic acid terminal is also end-capped by thermal decomposition. There is no.

  On the other hand, a method for producing a polyoxamide resin using an oxalic acid diester such as dialkyl oxalate as a monomer is also known, and polyoxamide resins by polycondensation with various diamines have been proposed. For example, a polyoxamide resin using 1,10-decanediamine, 1,9-nonanediamine, or 1,8-octanediamine as a diamine component (all are Patent Document 2) or a polyoxamide resin using 1,6-hexanediamine (non- Many polyoxamide resins have been proposed, such as Patent Document 1).

However, the known polyoxamide resin is prepared by previously preparing a raw material diamine using toluene or the like as a solvent, and then mixing a oxalic acid diester to obtain a prepolymer, and after distilling off the solvent from the prepolymer obtained here. A two-stage polymerization process was required, ie, a polycondensation process after melt polymerization or solid phase polymerization to obtain a polymer. For this reason, there is a problem that the production of the polyoxamide resin requires a lot of energy and time to distill off the solvent, which is not suitable for industrial production. There was no specific description about the order of preparation.
JP 2006-57033 A Special table 5-506466 SW Shalaby., J. Polym. Sci., 11, 1 (1973)

  The problem to be solved by the present invention is that a 96% sulfuric acid solution having a high molecular weight (polyamide resin concentration of 1.0 g / dl) is used without performing a pre-polycondensation step in a solvent necessary for the production of a conventional polyoxamide resin. And a method for producing a polyoxamide resin having a relative viscosity ηr measured at 25 ° C. of 2.2 to 6.0).

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a method for producing a polyamide resin characterized in that a raw material oxalic acid diester is previously charged in a container and then diamine is mixed. Completed the invention.

  By using the polyamide resin production method of the present invention, a 96% sulfuric acid solution having a high molecular weight (polyamide resin concentration of 1.0 g / dl) was used at 25 ° C. without performing the solution polymerization step required for the production of polyoxamide resin in the prior art. It was possible to obtain a polyoxamide resin having a measured relative viscosity ηr of 2.2 to 6.0).

(1) Constituent Component of Polyamide As the oxalic acid source of the polyoxamide resin to be produced in the present invention, oxalic acid diesters are used, and these are not particularly limited as long as they have reactivity with amino groups. Oxalic acid diesters of aliphatic monohydric alcohols such as dimethyl oxalate, diethyl oxalate, di-n- (or i-) propyl oxalate, di-n- (or i-, or t-) butyl oxalate, dicyclohexyl oxalate Oxalic acid diesters of alicyclic alcohols such as oxalic acid diesters of aromatic alcohols such as diphenyl oxalate. Among these, the oxalic acid diester that produces the alcohol in which the produced polyamide resin dissolves well in the alcohol generated by the polycondensation reaction in the pre-polycondensation step and can be completely removed at the subsequent melt polymerization and solid phase polymerization temperatures. Is preferably used. Examples of such oxalic acid diesters include dimethyl oxalate, diethyl oxalate, di-n- (or i-) propyl oxalate, di-n- (or i-, or t-) butyl oxalate. it can.

  As raw material diamine, ethylenediamine, propylenediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9- Nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl- Aliphatic diamines such as 1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine, and alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, and isophoronediamine; Furthermore, p-phenylenediamine, m-phenylenediamine, xylenedia Emissions, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, one or more of any mixture selected from aromatic diamines, such as 4,4'-diaminodiphenyl ether and the like.

(2) Manufacturing method of polyamide Hereinafter, the manufacturing method of this invention is demonstrated concretely. First, the raw material oxalic acid diester is charged into the container (charged and replaced with nitrogen) (charged. The solution may be replaced with an inert gas such as nitrogen gas). As long as it can withstand the pressure, it is not particularly limited. Thereafter, the container is heated to a temperature at which it is mixed with the raw material diamine, and then the diamine is injected to start the polycondensation reaction. The temperature at which the raw materials are mixed is not particularly limited as long as it is a temperature that is not lower than the melting point and lower than the boiling point of the oxalic acid diester and diamine, and the polyoxamide generated by the polycondensation reaction of the oxalic acid diester and diamine is not thermally decomposed. For example, it consists of a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 1:99 to 99: In the case of a polyoxamide resin using diamine 1 and dibutyl oxalate as raw materials, the mixing temperature is preferably 33 ° C. to 240 ° C. Moreover, since the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 6:94 to 85:15, it is liquid at room temperature or liquefied only by heating to about 40 ° C. It is more preferable because it is easy to handle. When the mixing temperature is equal to or higher than the boiling point of the alcohol produced by the condensation reaction, it is desirable to use a container equipped with a device for distilling and condensing the alcohol. In addition, when pressure polymerization is performed in the presence of an alcohol generated by a condensation reaction, a pressure vessel is used. The charging ratio of oxalic acid diester and diamine is oxalic acid diester / diamine as described above, 0.8 to 1.2 (molar ratio), preferably 0.91 to 1.09 (molar ratio), more preferably 0.98. -1.02 (molar ratio).

  Next, the inside of the container is heated to a temperature not lower than the melting point of the polyoxamide resin and not higher than the temperature at which it is not thermally decomposed. For example, a diamine and shu comprising 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 85:15. In the case of a polyoxamide resin using dibutyl acid as a raw material, the melting point is 235 ° C., so it is preferable to raise the temperature from 240 ° C. to 280 ° C. (pressure is 2 MPa to 4 MPa). While distilling off the produced alcohol, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. When the raw materials are mixed in a pressure vessel and subjected to pressure polymerization in the presence of an alcohol produced by a condensation reaction, the pressure is first released while the produced alcohol is distilled off. Thereafter, the polycondensation reaction is continued under an atmospheric pressure of nitrogen or reduced pressure as necessary. The preferable final pressure in the case of carrying out the vacuum polymerization is 760 to 0.1 Torr. The temperature is preferably 240 to 280 ° C. The alcohol is cooled and liquefied by a water-cooled condenser and recovered.

  The polyamide resin obtained from the present invention can be mixed with other diamine components within a range not impairing the effects of the present invention. Examples of diamine components other than 1,9-nonanediamine and 2-methyl-1,8-octanediamine include ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, and 1,8-octanediamine. 1,10-decanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1 , 6-hexanediamine, aliphatic diamines such as 5-methyl-1,9-nonanediamine, alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine and isophoronediamine, p-phenylenediamine, m-phenylenediamine, p -Xylenediamine, m-xylenediamine, 4,4'-di Mino diphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-and aromatic diamines, such as diaminodiphenyl ether by itself, or may be added to any mixture thereof during the polycondensation reaction.

(3) Properties and physical properties of polyamide The molecular weight of the polyamide obtained from the present invention is not particularly limited, but the relative viscosity ηr measured at 25 ° C. using a 96% sulfuric acid solution with a polyamide resin concentration of 1.0 g / dl is 2 Within the range of 2 to 6.0. If ηr is lower than 2.2, the molded product becomes brittle and the physical properties deteriorate. On the other hand, if ηr is higher than 6.0, the melt viscosity becomes high, and the molding processability deteriorates.

(4) Components that can be blended with the polyamide resin The polyamide resin obtained from the present invention can be mixed with other diamine components within a range that does not impair the effects of the present invention. Examples of diamine components other than 1,9-nonanediamine and 2-methyl-1,8-octanediamine include ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, and 1,8-octanediamine. 1,10-decanediamine, 1,12-dodecanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1 Aliphatic diamines such as cyclohexandiamine, methylcyclohexanediamine and isophoronediamine, p-phenylenediamine, m-phenylenediamine, p -Xylenediamine, m-xylenediamine, 4,4'-dia Aromatic diamines such as minodiphenylmethane, 4,4′-diaminodiphenylsulfone, and 4,4′-diaminodiphenyl ether can be added alone or in any mixture thereof during the polycondensation reaction.

  In the present invention, other polyoxamides, polyamides such as aromatic polyamides, aliphatic polyamides, and alicyclic polyamides can be mixed within a range not impairing the effects of the present invention. Furthermore, thermoplastic polymers other than polyamide, elastomers, fillers, reinforcing fibers, and various additives can be similarly blended.

  Furthermore, the polyamide resin obtained according to the present invention may optionally contain a stabilizer such as a copper compound, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, and a crystallization accelerator. Glass fiber, plasticizer, lubricant and the like can be added during or after the polycondensation reaction.

(5) Polyamide resin molding process The polyamide resin molding method obtained by the present invention includes all known molding process methods applicable to polyamide, such as injection, extrusion, hollow, press, roll, foaming, vacuum / pressure, and stretching. The film can be processed into a film, a sheet, a molded product, a fiber, or the like by these molding methods.

(6) Use of polyamide molded product Polyamide molded product obtained according to the present invention includes various molded products, sheets, films, pipes, tubes, monofilaments, fibers, containers, etc., for which conventional polyamide molded products have been used. It can be used in a wide range of applications such as computers and related equipment, optical equipment components, electrical / electronic equipment, information / communication equipment, precision equipment, civil engineering / building supplies, medical supplies, and household goods.

[Evaluation method]
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, the structural analysis in the examples, the calculation of the number average molecular weight, the calculation of the terminal group concentration, and the measurement of the relative viscosity were performed by the following methods.

(1) Structural analysis The primary structure was identified by ¹ H-NMR. ¹ H-NMR was measured using AVANCE 500 manufactured by Bruker BioSpin Corporation under the conditions of solvent: bisulfuric acid and integration: 1024 times.

(2) Number average molecular weight (Mn)
The number average molecular weight (Mn) is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine based on the signal intensity obtained from the ¹ H-NMR spectrum, and 1,9-nonanediamine and 2 -In the case of polyoxamide resin (hereinafter abbreviated as PA92 (NMDA / MODA = 85/15)) using diamine having a molar ratio of methyl-1,8-octanediamine of 85:15 and dibutyl oxalate as raw materials Calculated by the formula.
Mn = np × 212.30 + n (NH ₂ ) × 157.28 + n (OBu) × 129.14 + n (NHCHO) × 29.14

Moreover, each term in the said formula is prescribed | regulated as follows.
Np = Np / [(N (NH ₂ ) + N (NHCHO) + N (OBu)) / 2]
N (NH ₂ ) = N (NH ₂ ) / [(N (NH ₂ ) + N (NHCHO) + N (OBu)) / 2]
N (NHCHO) = N (NHCHO) / [(N (NH2) + N (NHCHO) + N (OBu)) / 2]
N (OBu) = N (OBu) / [(N (NH ₂ ) + N (NHCHO) + N (OBu)) / 2]
Np = [(Sp / sp) -1] / sp-N (NHCHO)
・ N (NH ₂ ) = S (NH ₂ ) / s (NH ₂ )
N (NHCHO) = S (NHCHO) / s (NHCHO)
N (OBu) = S (OBu) / s (OBu)

However, each term has the following meaning.
Np: total number of repeating units in the molecular chain excluding terminal units of PA92 (NMDA / MODA = 85/15).
Np: the number of repeating units in the molecular chain per molecule.
Sp: Integration value of a signal (near 3.1 ppm) based on the proton of the methylene group adjacent to the oxamide group in the repeating unit in the molecular chain excluding the end of PA92 (NMDA / MODA = 85/15).
Sp: Number of hydrogens counted in the integrated value Sp (2).
· N (NH _2): The total number of terminal amino groups of PA92 (NMDA / MODA = 85/ 15).
N (NH ₂ ): number of terminal amino groups per molecule.
S (NH ₂ ): integrated value of a signal (around 2.6 ppm) based on the proton of the methylene group adjacent to the terminal amino group of PA92 (NMDA / MODA = 85/15).
S (NH2): The number of hydrogens (2) counted in the integral value S (NH2).
N (NHCHO): total number of terminal formamide groups of PA92 (NMDA / MODA = 85/15).
N (NHCHO): number of terminal formamide groups per molecule.
-S (NHCHO): The integral value of the signal (7.8 ppm) based on the proton of the formamide group of PA92 (NMDA / MODA = 85/15).
S (NHCHO): The number of hydrogens (one) counted in the integral value S (NHCHO).
N (OBu): the total number of terminal butoxy groups of PA92 (NMDA / MODA = 85/15).
N (OBu): number of terminal butoxy groups per molecule.
S (OBu): integral value of a signal (around 4.1 ppm) based on protons of a methylene group adjacent to an oxygen atom of a terminal butoxy group of PA92 (NMDA / MODA = 85/15).
S (OBu): The number of hydrogens (two) counted in the integral value S (OBu).

(3) Terminal group concentration: When dibutyl oxalate was used, the terminal amino group concentration [NH ₂ ], the terminal butoxy group concentration [OBu], and the terminal formamide group concentration [NHCHO] were determined according to the following formulas.
Terminal amino group concentration [NH ₂ ] = n (NH ₂ ) / Mn
Terminal butoxy group concentration [OBu] = n (OBu) / Mn
Terminal formamide group concentration [NHCHO] = n (NHCHO) / Mn

(4) Relative viscosity (ηr)
ηr was measured at 25 ° C. using an Ostwald viscometer using a 96% polyamide sulfuric acid solution (concentration: 1.0 g / dl).

[Example 1]
The inside of a 500 mL separable flask equipped with a stirrer, a nitrogen inlet tube, a raw material inlet, and a butanol distillation tube is kept under a reduced pressure of 13.3 Pa or less, and then a nitrogen gas having a purity of 99.9999% Was repeated five times, and then 110.9 g (0.5484 mol) of dibutyl oxalate was charged using a funnel. This separable flask was placed in an oil bath and heated to 50 ° C., then 73.79 g (0.4662 mol) of 1,9-nonanediamine melted in an oven at 60 ° C., 2-methyl-1,8- A mixture of 13.02 g (0.08227 mol) of octanediamine (the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine was 85:15) was charged into the container over 30 seconds. At this time, the polymer produced by the polycondensation reaction was deposited in the container, and part of the butanol produced at the same time was distilled. Note that all operations from preparation of raw materials to completion of the reaction were performed under a nitrogen stream of 100 ml / min.

  About 10 g of the prepolymer obtained by the above operation was charged into a glass reaction tube having a diameter of about 35 mmφ equipped with a stirrer, an air cooling tube, and a nitrogen introduction tube, the inside of the reaction tube was kept under a reduced pressure of 13.3 Pa or less, and the purity was The operation of introducing 99.9999% nitrogen gas to atmospheric pressure was repeated 5 times, and then transferred to a salt bath maintained at 190 ° C., and a polycondensation reaction was performed for 3 hours under a nitrogen stream of 50 ml / min. The temperature of the salt bath was adjusted to 260 ° C. over 1 hour, and the reaction was further continued for 2 hours. Subsequently, the product was taken out from the salt bath and cooled to room temperature under a nitrogen stream of 50 ml / min. What was obtained was a white tough polymer.

[Example 2]
111.4 g (0.5507 mol) of dibutyl oxalate, 5.229 g (0.03304 mol) of 1,9-nonanediamine, and 81.93 g (0.5176 mol) of 2-methyl-1,8-octanediamine (The molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine is 6:94), except that the temperature in the container at the time of diamine injection is 27 ° C., the reaction is the same as in Example 1. The product was obtained. What was obtained was a white tough polymer.

[Example 3]
1L equipped with stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure release port, polymer outlet, and raw material feed port directly connected with raw material feed pump by SUS316 pipe with 1/8 inch diameter After charging 247.58 g (1.2242 mol) of dibutyl oxalate into a pressure vessel, the inside of the pressure vessel was pressurized to 3.0 MPa with nitrogen gas having a purity of 99.9999%, and then nitrogen gas was supplied to normal pressure. The operation of releasing was repeated 5 times, and then the temperature in the system was raised under a sealing pressure. After the internal temperature was raised to 100 ° C. over 30 minutes, a mixture of 11.63 g (0.07349 mol) of 1,9-nonanediamine and 182.24 g (1.1513 mol) of 2-methyl-1,8-octanediamine (1.1513 mol) The molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine was 6:94) was poured into the reaction vessel over 17 minutes at a flow rate of 13 ml / min by a raw material feed pump, and the temperature was increased. The internal pressure in the pressure vessel immediately after injection was increased to 0.35 MPa by 1-butanol generated by the polycondensation reaction, and the internal temperature was increased to 170 ° C. Release of butanol generated immediately after injection was started, and the internal temperature was maintained at 235 ° C. over 1 hour while maintaining the internal pressure at 0.25 MPa. Immediately after the internal temperature reached 235 ° C., 1-butanol produced by the polycondensation reaction was extracted from the pressure release port over 20 minutes. After releasing the pressure, the temperature was raised under a nitrogen stream of 50 ml / min, the internal temperature was raised to 260 ° C. over 1 hour, and the reaction was carried out at 260 ° C. for 4.5 hours. Thereafter, stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for 10 minutes. The string-like polymer was immediately cooled with water, and the water-cooled string-like polymer was pelletized with a pelletizer. The obtained polymer was a white polymer.

[Comparative Example 1]
The inside of a 500 mL separable flask equipped with a stirrer, a nitrogen inlet tube, a raw material inlet, and a butanol distillation tube is kept under a reduced pressure of 13.3 Pa or less, and then a nitrogen gas having a purity of 99.9999% Was repeated 5 times, and then was melted in an oven at 60 ° C., 74.56 g (0.4710 mol) of 1,9-nonanediamine and 13.16 g of 2-methyl-1,8-octanediamine. (0.08312 mol) of a mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine molar ratio 85:15) was charged using a funnel. After this separable flask was placed in an oil bath and heated to 50 ° C., 112.1 g (0.5542 mol) of dibutyl oxalate was charged into the container over 30 seconds. At this time, the polymer produced by the polycondensation reaction was deposited in the container, and part of the butanol produced at the same time was distilled. Note that all operations from preparation of raw materials to completion of the reaction were performed under a nitrogen stream of 100 ml / min.

  About 10 g of the prepolymer obtained by the above operation was charged into a glass reaction tube having a diameter of about 35 mmφ equipped with a stirrer, an air cooling tube, and a nitrogen introduction tube, the inside of the reaction tube was kept under a reduced pressure of 13.3 Pa or less, and the purity was The operation of introducing 99.9999% nitrogen gas to atmospheric pressure was repeated 5 times, and then transferred to a salt bath maintained at 190 ° C. under a nitrogen stream of 50 ml / min, and a polycondensation reaction was performed for 3 hours. The temperature of the salt bath was adjusted to 260 ° C. over 1 hour, and the reaction was further continued for 2 hours. Subsequently, the product was taken out from the salt bath and cooled to room temperature under a nitrogen stream of 50 ml / min. What was obtained was a yellow brittle polymer.

[Comparative Example 2]
1L equipped with stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure release port, polymer outlet, and raw material feed port directly connected with raw material feed pump by SUS316 pipe with 1/8 inch diameter In a pressure vessel, 59.76 g (0.3776 mol) of 1,9-nonanediamine, 10.55 g (0.06663 mol) of 2-methyl-1,8-octanediamine (1,9-nonanediamine and 2-methyl-1) , 8-octanediamine molar ratio is 85:15), the pressure vessel is pressurized to 3.0 MPa with 99.9999% purity nitrogen gas, and then the nitrogen gas is released to normal pressure. After repeating 5 times, the inside of the system was heated under a sealing pressure. After the internal temperature was brought to 210 ° C. over 2 hours, 89.33 g (0.4417 mol) of dibutyl oxalate was injected into the reaction vessel with a raw material feed pump at a flow rate of 5 ml / min for 17 minutes. At this time, the internal pressure in the pressure vessel rose to 0.95 MPa by 1-butanol produced by the polycondensation reaction, and the internal temperature rose to 217 ° C. Immediately after the injection of dibutyl oxalate, the temperature was raised and the internal temperature was raised to 260 ° C. over 1.5 hours. At this time, the internal pressure in the container was 2.25 MPa. Immediately after the internal temperature reached 260 ° C., stirring was stopped, and 1-butanol produced by the polycondensation reaction was withdrawn from the pressure release port over 17 minutes. After returning the system internal pressure to normal pressure, the system was placed under a nitrogen stream, and the polymer was extracted from the bottom of the container. The obtained polymer was a white polymer.

  Table 1 shows ηr, end group concentration, and number average molecular weight of the polyoxamide resins obtained in Examples 1 to 3 and Comparative Examples 1 and 2.

  FIG. 1 shows the NMR spectrum of the polyoxamide resin obtained in Example 1 in bisulfuric acid and the attribution of the obtained peak. In FIG. 1, the symbols a to o described in the chemical formula correspond to the symbols a to o shown in the peaks of the NMR spectrum.

  In the method of the present invention, as described in detail above, a high molecular weight polyoxamide resin can be obtained by previously preparing a raw material oxalic acid diester in a container and then mixing diamine. Moreover, while omitting the prepolymerization step in a conventionally known solvent, it is possible to omit the step of distilling off the solvent, and the time and energy required for this step, and produce a high molecular weight polyoxamide resin with high efficiency. be able to.

NMR spectrum of polyoxamide resin in bisulfuric acid.

Claims (6)

In the manufacturing method of the polyamide resin whose dicarboxylic acid component is oxalic acid , the raw material oxalic acid diester is charged beforehand, without mixing a solvent beforehand, and then a diamine is mixed.   2. The method for producing a polyamide resin according to claim 1, wherein an alcohol generated by a polycondensation reaction is used as a solvent.   The method for producing a polyamide resin according to claim 1 or 2, wherein a diamine having 6 to 12 carbon atoms is used as a raw material.   The raw material diamine consists of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 1:99 to 99: 1. The manufacturing method of the polyamide resin of Claim 1 or 2 which consists of a diamine component which is.   The method for producing a polyamide resin according to any one of claims 1 to 4, further comprising a step of mixing the raw materials in a pressure resistant container and performing pressure polymerization in the presence of an alcohol generated by a condensation reaction. Polyamide resin manufacturing method.   6. The method for producing a polyamide resin according to claim 5, wherein the polycondensation reaction is performed under normal pressure or reduced pressure after the alcohol is extracted from the pressure vessel pressurized by the alcohol generated by the condensation reaction and released. A process for producing a polyamide resin.

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