JP2009235225A - Polyamide resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyamide resin, which is sufficiently polymerized in comparison with a conventional polyamide 92, has a wide moldable temperature range estimated from a difference between a melting point and a thermal decomposition temperature and excellent melt moldability, and in comparison with a conventional aliphatic polyamide resin, exhibits excellent low ethanol absorbency, chemical resistance, hydrolysis resistance and the like without deteriorating low water absorbency observed in an aliphatic normal chain polyoxamide resin. <P>SOLUTION: The polyamide resin is obtained by condensing a dicarboxylic acid component and a diamine component. The dicarboxylic acid component consists of oxalic acid, while the diamine component consists of 1,9-nonane diamine and 2-methyl-1,8-octane diamine. The number of moles of 2-methyl-1,8-octane diamine is larger than that of the 1,9-nonane diamine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a novel polyamide resin. Specifically, it is a polyamide resin whose dicarboxylic acid component is oxalic acid, has a wide moldable temperature range, excellent molding processability, and low water absorption, low ethanol absorption, chemical resistance, hydrolysis resistance, etc. It relates to an excellent polyamide resin.

  Crystalline polyamides such as nylon 6 and nylon 66 are widely used as clothing, industrial material fibers, or general-purpose engineering plastics because of their excellent properties and ease of melt molding. Problems such as changes in physical properties due to water absorption, acid, high-temperature alcohol, and deterioration in hot water have also been pointed out, and there is an increasing demand for polyamides with superior dimensional stability and chemical resistance.

  On the other hand, a polyamide resin using oxalic acid as a dicarboxylic acid component is called a polyoxamide resin, and is known to have a higher melting point and lower water absorption than other polyamide resins having the same amino group concentration (Patent Document 1). It is expected to be used in fields where the use of conventional polyamide, where the change in physical properties due to water absorption has been a problem, is difficult.

  So far, polyoxamide resins using various aliphatic linear diamines as diamine components have been proposed. However, for example, a polyoxamide resin using 1,6-hexanediamine as a diamine component has a melting point (about 320 ° C.) higher than the thermal decomposition temperature (1% weight loss temperature in nitrogen; about 310 ° C.) (non-patent document). 1) Melt polymerization and melt molding were difficult and could not withstand practical use.

For a polyoxamide resin (hereinafter abbreviated as PA92) whose diamine component is 1,9-nonanediamine, L. Franco et al. Discloses a production method and crystal structure when diethyl oxalate is used as the oxalic acid source ( Non-patent document 2). The PA 92 obtained here is a polymer having an intrinsic viscosity of 0.97 dL / g and a melting point of 246 ° C., but only a low molecular weight substance that cannot form a tough molded article is obtained. In addition, JP-A-5-506466 discloses that PA92 having an intrinsic viscosity of 0.99 dL / g and a melting point of 248 ° C. was produced when dibutyl oxalate was used as the dicarboxylic acid ester ( Patent Document 2). In this case as well, there is a problem that only a low molecular weight body that cannot be formed into a tough molded body is obtained.
In the prior literature, there is no specific disclosure of a polyoxamide resin using two kinds of diamines of 1,9-nonanediamine and 2-methyl-1,8-octanediamine as a diamine component in a specific ratio.
SW Shalaby., J. Polym. Sci., 11, 1 (1973) L. Franco et al., Macromolecules., 31, 3912 (1988) JP 2006-57033 A Special table 5-506466

  The problem to be solved by the present invention is that a sufficiently high molecular weight is achieved as compared with the conventional PA92, the moldable temperature range estimated from the difference between the melting point and the thermal decomposition temperature is wide, and the melt moldability is excellent. Provided a polyamide resin with superior low ethanol absorption, chemical resistance and hydrolysis resistance compared to conventional aliphatic polyamide resin without impairing the low water absorption found in aliphatic linear polyoxamide resin There is to do.

  As a result of intensive studies to solve the above problems, the present inventors have used oxalic acid diester as the oxalic acid source, and the diamine component comprises 1,9-nonanediamine and 2-methyl-1,8-octanediamine. In addition, by using a mixture in which the molar ratio of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is 6:94 to 50:50, the difference between the melting point and the thermal decomposition temperature is high. Large, excellent melt moldability, and without impairing the low water absorption found in linear polyoxamide resins, it is possible to obtain polyamide resins that are superior in low ethanol absorption, chemical resistance, and hydrolysis resistance compared to conventional polyamides. As a result, the present invention has been completed.

  The polyamide resin of the present invention can have a high molecular weight by melt polymerization, has a wide moldable temperature range of 90 ° C. or more, is excellent in melt moldability, and further has low water absorption, low ethanol absorption, chemical resistance, resistance to resistance. Excellent hydrolyzability, used for automotive parts such as fuel tubes, air tubes, fuel auxiliary tanks, vapor canisters, quick connectors, fans, clips, fasteners, engine covers, radiator tanks, air duct hoses, armrests, gears, etc. it can. In addition, various molded products, sheets, films, pipes, tubes, monofilaments, fibers, containers, etc., for which polyamide molded products have been conventionally used, such as automobile members, computers and related equipment, optical equipment members, electrical / electronic equipment, information / electronic equipment, It can be widely used as a molding material for communication equipment, precision equipment, civil engineering / building supplies, medical supplies, and household goods.

(1) Constituent Component of Polyamide Resin In the polyamide of the present invention, the dicarboxylic acid component is oxalic acid, the diamine component is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and 1,9-nonanediamine. And 2-methyl-1,8-octanediamine is a polyamide resin which is a diamine mixture having a molar ratio of 6:94 to 50:50.

  As the oxalic acid source used in the production of the polyamide of the present invention, oxalic acid diesters are used, and these are not particularly limited as long as they have reactivity with amino groups. Dimethyl oxalate, diethyl oxalate, di-n-oxalate ( Or i-) propyl, oxalic acid diester of aliphatic monohydric alcohol such as di-n- (or i-, or t-) butyl oxalate, oxalic acid diester of alicyclic alcohol such as dicyclohexyl oxalate, aromatic alcohol such as diphenyl oxalate And oxalic acid diesters.

  Among the above oxalic acid diesters, oxalic acid diesters of aliphatic monohydric alcohols having more than 3 carbon atoms, oxalic acid diesters of alicyclic alcohols, and oxalic acid diesters of aromatic alcohols are preferred, and among them, dibutyl oxalate and diphenyl oxalate are particularly preferred.

  As the diamine component, a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is used. Furthermore, the molar ratio of the 1,9-nonanediamine component and the 2-methyl-1,8-octanediamine component is 6:94 to 50:50 mol%, preferably 6:94 to 40:60 mol%, and more. Preferably it is 6: 94-30: 70 mol%. By copolymerizing 1,9-nonanediamine and 2-methyl-1,8-octanediamine as described above, the moldable temperature range is wide, the melt moldability is excellent, and the low water absorption, chemical resistance, resistance A polyamide having excellent hydrolyzability can be obtained.

(2) Manufacture of polyamide resin The polyamide resin of this invention can be manufactured using the arbitrary methods known as a method of manufacturing polyamide. According to the study by the present inventors, it can be obtained by subjecting diamine and oxalic acid diester to a polycondensation reaction in a batch or continuous manner. Specifically, it is preferable to carry out in the order of (i) pre-polycondensation step and (ii) post-polycondensation step as shown by the following operations.

  (I) Pre-polycondensation step: First, the inside of the reactor is purged with nitrogen, and then diamine (diamine component) and oxalic acid diester (oxalic acid source) are mixed. When mixing, a solvent in which both the diamine and the oxalic acid diester are soluble may be used. The solvent in which both the diamine component and the oxalic acid source are soluble is not particularly limited, but toluene, xylene, trichlorobenzene, phenol, trifluoroethanol, and the like can be used, and particularly, toluene can be preferably used. For example, after heating the toluene solution which melt | dissolved diamine to 50 degreeC, oxalic acid diester is added with respect to this. At this time, the charging ratio of the oxalic acid diester and the diamine is oxalic acid diester / the diamine, 0.8 to 1.5 (molar ratio), preferably 0.91 to 1.1 (molar ratio), more preferably 0. .99 to 1.01 (molar ratio).

  The temperature in the reactor charged in this way is increased under normal pressure while stirring and / or nitrogen bubbling. The reaction temperature is preferably controlled so that the final temperature reaches 80 to 150 ° C, preferably 100 to 140 ° C. The reaction time at the final temperature reached is 3-6 hours.

  (Ii) Post-polycondensation step: In order to further increase the molecular weight, the polymer produced in the pre-polycondensation step is gradually heated in the reactor under normal pressure. In the temperature rising process, the final temperature of the prepolycondensation step, that is, from 80 to 150 ° C, is finally 220 ° C to 300 ° C, preferably 230 ° C to 280 ° C, more preferably 240 ° C to 270 ° C. Let reach the range. It is preferable to carry out the reaction for 1 to 8 hours including the temperature raising time, preferably 2 to 6 hours. Furthermore, in the post-polymerization step, polymerization can be performed under reduced pressure as necessary. The preferable final ultimate pressure in the case of performing the vacuum polymerization is less than 0.1 MPa to 13.3 Pa.

(3) Properties and properties of polyamide resin There is no particular limitation on the molecular weight of the polyamide resin obtained from the present invention, but the relative value measured at 25 ° C. using a 96% concentrated sulfuric acid solution with a polyamide resin concentration of 1.0 g / dl. The viscosity ηr is in the range of 1.8 to 6.0. Preferably it is 2.0-5.5, and 2.5-4.5 is especially preferable. If ηr is lower than 1.8, 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.

  The polyamide resin of the present invention comprises oxalic acid and 1,9-nonanediamine by copolymerizing oxalic acid as the carboxylic acid component and copolymerizing 1,9-nonanediamine and 2-methyl-1,8-octanediamine as the diamine component. Compared to polyamide, the relative viscosity can be increased, that is, the molecular weight can be increased. The moldable temperature range represented by the difference (Td−Tm) between the 1% weight loss temperature (hereinafter abbreviated as Td) and the melting point (hereinafter abbreviated as Tm), which is a substantial thermal decomposition index, is oxalic acid. And a polyamide composed of 1,9-nonanediamine, preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and even 90 ° C. or higher. The polyamide resin of the present invention has a Td of preferably 300 ° C. or higher, more preferably 320 ° C. or higher, and has high heat resistance.

(4) Components that can be blended with the polyamide resin The polyamide resin obtained according to the present invention can be mixed with other dicarboxylic acid components as long as the effects of the present invention are not impaired. Other dicarboxylic acid components other than succinic acid include malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, 3, Aliphatic dicarboxylic acids such as 3-diethylsuccinic acid, azelaic acid, sebacic acid and suberic acid, alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid, and terephthalic acid , Isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, dibenzoic acid Acid, 4,4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenyls Hong-4,4'-dicarboxylic acid, 4,4'-biphenyl and the like alone aromatic dicarboxylic acids such as dicarboxylic acids, or may be added to any mixture thereof during the polycondensation reaction. Furthermore, polyvalent carboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid can be used as long as melt molding is possible.

  The polyamide resin obtained from the present invention can be mixed with other diamine components as long as the effects of the present invention are not impaired. 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.

  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.

[Physical property measurement, molding, evaluation method]
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, relative viscosity in the examples, melting point, crystallization temperature, 1% weight loss temperature, measurement of melt viscosity and saturated water absorption, chemical resistance, evaluation of hydrolysis resistance, film molding and tensile strength, tensile elongation, The bending strength, flexural modulus, impact strength, and heat distortion temperature were measured by the following methods.

(1) 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).

(2) Melting point (Tm) and crystallization temperature (Tc)
Tm and Tc were measured under a nitrogen atmosphere using a PYRIS Diamond DSC manufactured by PerkinELmer. The temperature was raised from 30 ° C. to 270 ° C. at a rate of 10 ° C./min (referred to as a temperature rise first run), held at 270 ° C. for 3 minutes, and then lowered to −100 ° C. at a rate of 10 ° C./min (temperature fall first). Then, the temperature was raised to 270 ° C. at a rate of 10 ° C./min (called a temperature raised second run). From the obtained DSC chart, the exothermic peak temperature of the temperature decrease first run was Tc, and the endothermic peak temperature of the temperature increase second run was Tm.

(3) 1% weight loss temperature (Td)
Td was measured by thermogravimetric analysis (TGA) using THERMOGRAVIMETRIC ANALYZER TGA-50 manufactured by Shimadzu Corporation. The temperature was raised from room temperature to 500 ° C. at a rate of 10 ° C./min under a nitrogen stream of 20 ml / min, and Td was measured.

(4) Film formation Film formation was performed using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. After being melted by heating at 260 ° C. for 5 minutes in a reduced pressure atmosphere of 500 to 700 Pa, the film was formed by pressing at 5 MPa for 1 minute. Next, the reduced-pressure atmosphere was returned to normal pressure, and then cooled and crystallized at room temperature of 5 MPa for 1 minute to obtain a film.

(5) Saturated water absorption rate A film (dimensions: 20 mm × 10 mm, thickness 0.25 mm; weight about 0.05 g) obtained by molding a polyamide resin under the condition (4) is immersed in ion-exchanged water at 23 ° C. for a predetermined time. Each time the film was removed and the weight of the film was measured. When the rate of increase in the film weight lasts three times in the range of 0.2%, it is determined that the absorption of water into the polyamide resin film has reached saturation, and the film weight (Xg) before dipping in water The saturated water absorption (%) was calculated from the weight (Yg) of the film when the saturation was reached by the formula (1).

(6) Sheet forming A disk having a diameter of about 50 mm and a thickness of about 2 mm was formed using a vacuum press TMB-10 manufactured by Toho Machinery Co., Ltd. After being melted by heating at 260 ° C. for 5 minutes in a reduced pressure atmosphere of 500 to 700 Pa, pressing was performed at 5 MPa for 1 minute to form. Next, the reduced pressure atmosphere was returned to normal pressure, and then cooled and crystallized at 145 ° C. and 5 MPa for 1 minute to obtain a sample.

(7) Saturated ethanol absorption rate A disk-shaped sample (dimensions: diameter of about 50 mm, thickness of about 2 mm; weight of about 3.54 g) molded from a polyamide resin under the conditions of (6) is immersed in reagent-grade ethanol at 25 ° C. The sample was taken out every predetermined time, and the weight was measured. When the increase rate of the sample weight lasts 3 times in the range of 0.2%, it is judged that the absorption of ethanol into the polyamide resin has reached saturation, and the sample weight (Xg) before being immersed in ethanol is saturated. The saturated ethanol absorption rate (%) was calculated from the weight (Yg) of the sample at the time of reaching Equation (2) by the formula (2).

(8) Mechanical properties [1] to [3] shown below were measured by molding the following test pieces by injection molding at a resin temperature of 260 ° C. and a mold temperature of 80 ° C.
[1] Tensile test (tensile yield point strength and tensile elongation at break): Measured at 23 ° C. in accordance with ASTM D638 using a Type I test piece described in ASTM D638.
[2] Bending test (bending strength and flexural modulus): Measured at 23 ° C. in accordance with ASTM D790 using a test piece having a test piece size of 129 mm × 12.7 mm × 3.2 mm.
[3] Impact strength (with Izod notch): Measured at 23 ° C. in accordance with ASTM D256 using a test piece having a size of 63.5 mm × 12.7 mm × 3.2 mm.

[Example 1]
(I) Pre-polycondensation step: The interior of a 500 ml separable flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, and raw material inlet is replaced with nitrogen gas having a purity of 99.9999% for dehydration. 200 ml of used toluene, 16.129 g (0.1018 mol) of 1,9-nonanediamine, and 16.129 g (0.1018 mol) of 2-methyl-1,8-octanediamine were charged. After this separable flask was placed in an oil bath and heated to 50 ° C., 41.1761 g (0.2036 mol) of dibutyl oxalate was charged. Next, the temperature of the oil bath was raised to 130 ° C., and the reaction was carried out for 5 hours under reflux. Note that all operations from preparation of raw materials to completion of the reaction were performed under a nitrogen stream of 50 ml / min.

  (Ii) Post-polycondensation step: The prepolymer obtained by the above operation is 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, and the pressure inside the reaction tube is reduced to 13.3 Pa or less. Then, the operation of introducing nitrogen gas to normal pressure was repeated five times, and then the mixture was transferred to a salt bath maintained at 210 ° C. under a nitrogen stream of 50 ml / min, and temperature increase was immediately started. After the temperature of the salt bath was adjusted to 260 ° C. over 1 hour, the inside of the container was depressurized to about 66.5 Pa and further reacted for 2 hours. Subsequently, after introducing nitrogen gas to normal pressure, it was removed from the salt bath and cooled to room temperature under a nitrogen stream of 50 ml / min to obtain a polyamide resin. The obtained polyamide was a white tough polymer.

[Example 2]
In the prepolymerization step, the same as in Example 1 except that 9.6777 g (0.0611 mol) of 1,9-nonanediamine and 22.5581 g (0.1425 mol) of 2-methyl-1,8-octanediamine were charged. Reaction was performed to obtain polyamide. The obtained polyamide was a white tough polymer.

[Example 3]
In the prepolymerization step, the same as in Example 1 except that 1.9335 g (0.122 mol) of 1,9-nonanediamine and 30.2923 g (0.1914 mol) of 2-methyl-1,8-octanediamine were charged. Reaction was performed to obtain polyamide. The obtained polyamide was a white tough polymer.

[Example 4]
(I) Pre-polycondensation step: A raw material feed pump was directly connected by a stirrer, a thermometer, a torque meter, a pressure gauge, a nitrogen gas inlet, a pressure outlet, a polymer outlet, and a pipe made of SUS316 having a diameter of 1/8 inch. After charging 224.12 g (1.1083 mol) of dibutyl oxalate into a 1 L pressure vessel equipped with a raw material inlet, the inside of the pressure vessel was pressurized to 3.0 MPa with nitrogen gas having a purity of 99.9999%, Next, the operation of releasing nitrogen gas to normal pressure was repeated 5 times, and then 105.9 g (0.06687 mol) of 1,9-nonanediamine and 2-methyl-1,8-octanediamine 165 at 40 ° C. under a sealing pressure. .83 g (1.0477 mol) of a mixture (1,9-nonanediamine and 2-methyl-1,8-octanediamine molar ratio of 6:94) was mixed with a raw material feed pump. It was injected into the reaction vessel over a period of 1 minute at a flow rate of 200ml / min. The temperature in the pressure vessel immediately after the injection rose to 137 ° C.
(Ii) Post-polycondensation step: Thereafter, the temperature was raised under a nitrogen stream of 40 ml / min, and the reaction was carried out for 2 hours after the internal temperature was raised to 260 ° C over 5.5 hours. Next, the stirring was stopped, the inside of the system was pressurized to 1 MPa with nitrogen and allowed to stand for 10 minutes, and then the polymer was extracted from the lower part of the pressure vessel in a string shape. 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 tough polymer. The relative viscosity was 3.47.

[Example 5]
(I) Pre-polycondensation step: A raw material feed pump was directly connected by a stirrer, a thermometer, a torque meter, a pressure gauge, a nitrogen gas inlet, a pressure outlet, a polymer outlet, and a pipe made of SUS316 having a diameter of 1/8 inch. After charging 1048.87 g (5.18616 mol) of dibutyl oxalate into a 5 L pressure vessel equipped with a raw material inlet, the inside of the pressure vessel was pressurized to 3.0 MPa with nitrogen gas having a purity of 99.9999%, Next, the operation of releasing nitrogen gas to normal pressure was repeated five times, and then the system was heated under a sealing pressure. After the internal temperature was raised to 100 ° C. over 20 minutes, a mixture of 49.26 g (0.3112 mol) of 1,9-nonanediamine and 771.74 g (4.8756 mol) of 2-methyl-1,8-octanediamine (4.8756 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 of the entire amount increased to 0.35 MPa by 1-butanol generated by the polycondensation reaction, and the internal temperature increased to 168 ° C.
(Ii) Post-polycondensation step: Distillation of butanol produced immediately after injection was started, and the internal temperature was maintained at 235 ° C. over 2 hours 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 260 ml / min. The internal temperature was raised to 260 ° C. over 1 hour, and the reaction was carried out at 260 ° C. for 0.5 hour. Thereafter, the stirring was stopped, the inside of the system was pressurized to 3 MPa with nitrogen and allowed to stand for 10 minutes, and then released to an internal pressure of 0.5 MPa, and the polymer was extracted from the lower part of the pressure vessel in a string shape. 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 tough polymer. The relative viscosity was 4.00.

[Comparative Example 1]
(I) Pre-polycondensation step: The inside of a 1 L separable flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, and raw material inlet is replaced with nitrogen gas having a purity of 99.9999% for dehydration. 500 ml of used toluene, 68.3091 g (0.4316 mol) of 1,9-nonanediamine and 12.0545 g (0.0762 mol) of 2-methyl-1,8-octanediamine were charged. This separable flask was placed in an oil bath and heated to 50 ° C., and then 102.1195 g (0.5053 mol) of dibutyl oxalate was charged. Next, the temperature of the oil bath was raised to 130 ° C., and the reaction was carried out for 5 hours under reflux. Note that all operations from preparation of raw materials to completion of the reaction were performed under a nitrogen stream of 50 ml / min.

  (Ii) Post-polycondensation step: The prepolymer obtained by the above operation is 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, and the pressure inside the reaction tube is reduced to 13.3 Pa or less. Then, the operation of introducing nitrogen gas to normal pressure was repeated five times, and then the mixture was transferred to a salt bath maintained at 210 ° C. under a nitrogen stream of 50 ml / min, and temperature increase was immediately started. After the temperature of the salt bath was adjusted to 260 ° C. over 1 hour, the inside of the container was depressurized to about 66.5 Pa and further reacted for 2 hours. Subsequently, after introducing nitrogen gas to normal pressure, it was removed from the salt bath and cooled to room temperature under a nitrogen stream of 50 ml / min to obtain a polyamide resin. The obtained polyamide was a white tough polymer.

[Comparative Example 2]
In the prepolymerization step, a separable flask having a volume of 500 ml was used, 200 ml of dehydrated toluene, 18.9835 g (0.1199 mol) of 1,9-nonanediamine, and 4.759 g of 2-methyl-1,8-octanediamine (0 0.0300 mol) and 30.1957 g (0.1493 mol) of dibutyl oxalate were charged, and a reaction was carried out in the same manner as in Example 1 to obtain a polyamide. The obtained polyamide was a white tough polymer. The film formed from this polyamide was a colorless transparent tough film.

[Comparative Example 3]
(I) Pre-polycondensation step: The inside of a separable flask having a volume of 5 liters equipped with a stirrer, an air cooling tube, a nitrogen introduction tube, and a raw material inlet is replaced with nitrogen gas having a purity of 99.9999%, and oxalic acid 1211 g (5.99871 mol) of dibutyl was charged. While maintaining this container at 20 ° C., 807.6 g (5.102 mol) of 1,9-nonanediamine and 142.5 g (0.9004 mol) of 2-methyl-1,8-octanediamine were added while stirring, and polycondensation was performed. Reaction was performed. Note that all operations from preparation of raw materials to completion of the reaction were performed under a nitrogen stream of 200 ml / min.

  (Ii) Post-polycondensation step: The prepolymer obtained by the above operation is charged into a 5 L pressure vessel equipped with a stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet and polymer outlet, and the inside of the pressure vessel Was maintained under a pressure of 3.0 MPa or more and then the operation of releasing nitrogen gas to normal pressure was repeated five times, and then the system was heated under a nitrogen stream and normal pressure. The internal temperature was raised to 120 ° C. over 1.5 hours. At this time, distillation of butanol was confirmed. While distilling butanol, the temperature was raised to 260 ° C. over 5 hours and reacted for 2 hours. Thereafter, the temperature in the system was lowered to 250 ° C., stirring was stopped, and the system was allowed to stand for 25 minutes, and then the system was pressurized to 3.5 MPa with nitrogen, and the polymer was extracted from the lower part of the pressure vessel in a string shape. 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 tough polymer. Next, this polyamide was injection molded at a cylinder temperature of 260 ° C., a mold temperature of 80 ° C., and an injection peak pressure of 140 MPa, and various physical property values of the obtained molded product were measured. The results obtained are shown in Table 5 below.

[Comparative Example 4]
Using a separable flask having a volume of 300 ml in the prepolymerization step, 100 ml of dehydrated toluene, 21.2125 g (0.1340 mol) of 1,9-nonanediamine, and 27.0852 g (0.1339 mol) of dibutyl oxalate were added. A polyamide was obtained by reacting in the same manner as in Example 1 except that the polymerization was carried out at normal pressure in the post-polymerization step. The obtained polyamide was a yellow polymer.

The diamine composition, ηr, melting point (Tm), crystallization temperature (Tc) of the polyamides obtained in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4, Table 1 shows the 1% weight loss temperature (Td), Td-Tm, and melt viscosity. The Td-Tm of the polyamides obtained in Examples 1, 2, and 3 is larger than that of the polyamides obtained in Comparative Examples 1, 2, 3, and 4, and the molding process temperature range is wide. Moreover, Td of the polyamide obtained by Examples 1, 2, and 3 is higher than Td of Comparative Examples 1, 2, 3, and 4, and is excellent in heat resistance.

[Comparative Example 5]
A film was molded using nylon 6 (UBE Nylon 1015B, manufactured by Ube Industries) instead of the polyamide resin obtained in the present invention. The obtained nylon 6 film was a colorless transparent tough film. The saturated water absorption of this film was evaluated. The results are shown in Table 2.

[Comparative Example 6]
Instead of the polyamide resin obtained in the present invention, a film was formed using nylon 12 (UBE Kosan, UBESTA 3014U). The obtained nylon 12 film was a colorless transparent tough film. The saturated water absorption of this film was evaluated. The results are shown in Table 2.

  Table 2 shows the saturated water absorption rates of the polyamide resins obtained in Example 4, Comparative Example 2, Comparative Example 5, and Comparative Example 6. Table 3 shows saturated ethanol absorption rates of the polyamide resins obtained in Example 5 and Comparative Example 3. From Table 2, the polyamide resin of the present invention has low water absorption compared to nylon 6 and 12. Also, from Table 3, the polyamide resin of the present invention has low water absorption compared to the case where the number of moles of 2-methyl-1,8-octanediamine is less than the number of moles of 1,9-nonanediamine. Absorption.

  Table 4 shows the mechanical properties of the polyamide resin injection-molded articles obtained in Example 5 and Comparative Example 3.

飽和吸水率

Saturated water absorption

飽和エタノール吸収率

Saturated ethanol absorption rate

機械的物性

Mechanical properties

  The polyamide of the present invention is a polyoxamide resin excellent in low water absorption, low ethanol absorption, chemical resistance, hydrolysis resistance, etc., and excellent in melt molding processability. It can be suitably used as a molding material for automobile members, computers and related equipment, optical equipment members, electrical / electronic equipment, information / communication equipment, precision equipment, civil engineering / building supplies, medical supplies, household goods, and the like. For example, it can be used for automobile members such as fuel tubes, air tubes, fuel auxiliary tanks, vapor canisters, quick connectors, fans, clips, fasteners, engine covers, radiator tanks, air duct hoses, armrests, and gears. In addition, various molded products, sheets, films, pipes, tubes, monofilaments, fibers, containers, etc., for which polyamide molded products have been conventionally used, such as automobile members, computers and related equipment, optical equipment members, electrical / electronic equipment, information / electronic equipment, It can be widely used as a molding material for communication equipment, precision equipment, civil engineering / building supplies, medical supplies, and household goods.

Claims (6)

  The dicarboxylic acid component is composed of oxalic acid, the diamine component is composed of 1,9-nonanediamine and 2-methyl-1,8-octanediamine, and the number of moles of the 2-methyl-1,8-octanediamine is 1 , 9-nonanediamine, and a polyamide resin obtained by condensing the dicarboxylic acid component and the diamine component.   2. The relative viscosity (ηr) of a polyamide resin solution having a concentration of 1.0 g / dl with a 96% sulfuric acid aqueous solution as a solvent and a 96% sulfuric acid aqueous solution is 1.8 to 6.0 at 25 ° C. The polyamide resin described.   1% weight loss temperature in thermogravimetric analysis measured at 10 ° C./min heating rate under nitrogen atmosphere and differential scanning calorimetry measured at 10 ° C./min heating rate under nitrogen atmosphere The polyamide resin according to claim 1 or 2, wherein the temperature difference from the melting point is 50 ° C or more.   A process for producing a polyamide resin obtained by condensing a dicarboxylic acid component and a diamine component, wherein the dicarboxylic acid component comprises oxalic acid, and the diamine component comprises 1,9-nonanediamine and 2-methyl-1,8-octane. A method for producing a polyamide resin, comprising a diamine, wherein the number of moles of the 2-methyl-1,8-octanediamine is not less than the number of moles of the 1,9-nonanediamine.   The molded article formed by shape | molding the polyamide resin of any one of Claims 1-3.   The component for ethanol containing fuel formed by shape | molding the polyamide resin of any one of Claims 1-3.