JP6273883B2 - Polyamide resin - Google Patents

Description

  The present invention relates to a novel polyamide resin.

  Crystalline polyamide resins represented by nylon 6 and nylon 66 are widely used as textiles for clothing, industrial materials, or general-purpose engineering plastics because of their excellent properties and ease of melt molding. Has pointed out problems such as changes in physical properties due to water absorption, and there is an increasing demand for polyamide resins with superior dimensional stability.

  On the other hand, a polyamide resin using an oxalic acid compound 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). In addition, it is expected to be used in fields where conventional polyamides are difficult to use due to changes in physical properties due to water absorption.

  So far, polyoxamide resins using various aliphatic linear diamines as diamine components have been proposed. For example, Non-Patent Document 1 discloses a polyoxamide resin using 1,6-hexanediamine as a diamine component. Non-Patent Document 2 discloses a polyoxamide resin (hereinafter also referred to as PA92) whose diamine component is 1,9-nonanediamine. Non-Patent Document 3 discloses a polyoxamide resin using 1,4-butanediamine as a diamine component. Patent Document 2 discloses a polyoxamide resin using a diamine having 2 to 20 carbon atoms as a diamine component and dibutyl oxalate as a dicarboxylic acid ester. Patent Document 3 discloses 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. Patent Document 4 discloses a polyoxamide resin using various diamine components and oxalic acid.

  Patent Document 5 discloses a polyoxamide resin using 1,6-hexanediamine and 2-methyl-1,5-pentanediamine as diamine components. It is stated that these polyoxamide resins have a maximum melting point of 326 ° C., high heat resistance and excellent melt moldability.

Furthermore, polyamide resins are widely used as fuel peripheral members for automobiles. In recent years, the use of alcohol-mixed fuels in which bioethanol is mixed with gasoline has progressed, and alcohol barrier properties are required for fuel tanks and fuel tubes. However, the alcohol barrier properties of polyamide resins such as nylon 6 are insufficient. In contrast, Patent Document 6 discloses an ethanol barrier material using polyoxamide, but the barrier property is not sufficient.

JP 2006-57033 A Japanese National Patent Publication No. 5-506466 WO2008 / 072754 U.S. Pat. No. 2,130,948 WO2011 / 136263 JP 2009-298860 A

S. W. Shalaby, J. Polym. Sci., 11, 1 (1973) L. Franco et al., Macromolecules, 31, 3912 (1998) R. J. Gaymans et al., J. Polym. Sci. Polym. Chem. Ed., 22, 1373 (1984)

  In general, a resin having high crystallinity has a high amount of crystallization heat and high mechanical properties and heat resistance. Therefore, high crystallinity is also demanded for members used in polyamide resins under high temperature conditions and high load conditions. In the case of a polyamide resin using an oxalic acid compound as a raw material, the crystallinity is high (that is, the heat of crystallization is high), but the moldability is poor, or conversely, the crystallinity is low (that is, the heat of crystallization is low), The moldability is often excellent, and a polyamide resin using an oxalic acid compound as a raw material having high crystallinity and excellent moldability has not been found so far.

  The problem to be solved by the present invention is to provide a polyamide resin having high crystallinity and excellent moldability as compared with conventional polyamide resins.

As a result of intensive studies to solve the above problems, the present inventors have used oxalic acid compounds as dicarboxylic acid components, and 1,5-pentanediamine and 2-methyl-1,5-pentanediamine as diamine components. It was found that a polyamide resin having high crystallinity and excellent moldability can be obtained by using. Moreover, compared with the conventional polyamide resin, the polyamide resin of the present invention is excellent in low water absorption, chemical resistance, hydrolysis resistance, ethanol barrier property, and the like. The present invention is as follows:
1. A polyamide resin comprising a unit derived from a dicarboxylic acid component and a unit derived from a diamine component, wherein the dicarboxylic acid component contains an oxalic acid compound, and the diamine component is 1,5-pentanediamine and 2-methyl-1,5-pentane. Polyamide resin containing diamine.
2. 2. The polyamide resin according to 1 above, wherein the heat of fusion measured by a differential scanning calorimetry method at a rate of temperature increase of 10 ° C./min in a nitrogen atmosphere is 32 J / g or more.
3. 3. The polyamide resin as described in 1 or 2 above, wherein the heat of crystallization measured by the differential scanning calorimetry at a temperature drop rate of 10 ° C./min in a nitrogen atmosphere is 35 J / g or more.
4). 4. The polyamide resin according to any one of 1 to 3 above, wherein a melting point measured by a differential scanning calorimetry method at a heating rate of 10 ° C./min in a nitrogen atmosphere is 200 ° C. or higher.
5. There is a temperature difference between the crystallization temperature measured by the differential scanning calorimetry at a temperature decrease rate of 10 ° C./min in a nitrogen atmosphere and the melting point measured by the differential scanning calorimetry at a temperature increase rate of 10 ° C./min in a nitrogen atmosphere. The polyamide resin according to any one of 1 to 4 above, which exceeds 24 ° C.
6). The polyamide resin according to any one of 1 to 5 above, wherein the molar ratio of 1,5-pentanediamine and 2-methyl-1,5-pentanediamine is 10:90 to 80:20.

  The polyamide resin of the present invention has high crystallinity and excellent moldability. Moreover, it is excellent in low water absorption, chemical resistance, hydrolysis resistance, ethanol barrier property, and the like, and can be widely used as molding materials for industrial materials, industrial materials, household products and the like. In particular, the polyamide resin of the present invention can be expected to be used as a fuel peripheral member (fuel tube, fuel tank, etc.) of an automobile.

  In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

（式中、Ｒは、単結合又は２価の有機基である）で表されるジカルボン酸成分由来の単位と、下記式（２）：

（式中、Ｒ′は、２価の有機基である）で表されるジアミン成分由来の単位とが、アミド結合を形成して結合したポリマーである。 The polyamide resin of the present invention is a polyamide resin comprising a unit derived from a dicarboxylic acid component and a unit derived from a diamine component, wherein the dicarboxylic acid component contains an oxalic acid compound, and the diamine component is 1,5-pentanediamine and 2- It contains methyl-1,5-pentanediamine. Generally, the polyamide resin has the following formula (1):

(Wherein R is a single bond or a divalent organic group) and a unit derived from a dicarboxylic acid component represented by the following formula (2):

(Wherein R ′ is a divalent organic group) is a polymer in which units derived from a diamine component are bonded to form an amide bond.

で表される蓚酸化合物由来の単位を含む。したがって、蓚酸化合物としては、ジアミン成分のアミノ基とアミド結合を形成し、かつ上記式（１′）で表される単位を誘導しうる化合物であればよく、蓚酸若しくはその塩、蓚酸モノエステル若しくはその塩、又は蓚酸ジエステル等を挙げることができる。重縮合反応における副反応を抑制する観点から、蓚酸ジエステル、例えば、蓚酸ジメチル、蓚酸ジエチル、蓚酸ジ（ｎ若しくはiso）プロピル、蓚酸ジ（ｎ、iso、sec若しくはtert）ブチル、蓚酸ジヘキシル等のアルキル基が炭素数１〜６の直鎖又は分岐鎖状の炭化水素基である蓚酸ジアルキルエステル、蓚酸ジシクロヘキシル等のシクロアルキル基が炭素数３〜６の環状の炭化水素基である蓚酸ジシクロアルキルエステル、蓚酸ジフェニル等の蓚酸ジアリールエステル等が好ましく、その中でも蓚酸ジブチル及び蓚酸ジフェニルがより好ましく、蓚酸ジブチルが最も好ましい。 [Dicarboxylic acid component]
The polyamide resin of the present invention contains an oxalic acid compound as a dicarboxylic acid component. That is, the polyamide resin of the present invention has the following formula (1 ′) as a unit derived from a dicarboxylic acid component.

The unit derived from the oxalic acid compound represented by these is included. Accordingly, the oxalic acid compound may be any compound that forms an amide bond with the amino group of the diamine component and can derive the unit represented by the above formula (1 ′), and includes oxalic acid or a salt thereof, oxalic acid monoester or Examples thereof include salts thereof and oxalic acid diesters. From the viewpoint of suppressing side reactions in the polycondensation reaction, alkyl oxalate diesters such as dimethyl oxalate, diethyl oxalate, di (n or iso) propyl oxalate, di (n, iso, sec or tert) butyl oxalate, dihexyl oxalate, etc. Oxalic acid dicycloalkyl ester whose group is a linear or branched hydrocarbon group having 1 to 6 carbon atoms, cycloalkyl group such as dicyclohexyl oxalate is a cyclic hydrocarbon group having 3 to 6 carbon atoms Of these, diaryl oxalate such as diphenyl oxalate is preferable, among which dibutyl oxalate and diphenyl oxalate are more preferable, and dibutyl oxalate is most preferable.

[Diamine component]
The polyamide resin of the present invention contains 1,5-pentanediamine and 2-methyl-1,5-pentanediamine as diamine components. That is, the polyamide resin of the present invention is a unit derived from 1,5-pentanediamine as a unit derived from a diamine component [in the above formula (2), R ′ is pentamethylene] and 2-methyl-1, A unit derived from 5-pentanediamine [in which R ′ is 2-methyl-pentamethylene in the above formula (2)]. In order to obtain a polyamide resin having high crystallinity, excellent moldability, low water absorption, chemical resistance, hydrolysis resistance, and ethanol barrier properties, the unit derived from 1,5-pentanediamine and 2 -The molar ratio of units derived from methyl-1,5-pentanediamine is preferably 5:95 to 90:10, more preferably 10:90 to 80:20, and 15:85 to 80: More preferably, it is 20.

[Relative viscosity ηr of polyamide resin]
The polyamide resin of the present invention avoids the tendency that the molded article after melt molding becomes brittle and the physical properties are lowered, and from the viewpoint of avoiding the tendency that the melt viscosity at the time of melt molding becomes high and the molding processability deteriorates. The relative viscosity ηr measured at 25 ° C. using a 96% concentrated sulfuric acid solution having a concentration of 1.0 g / dl is preferably 1.5 to 6.0, more preferably 1.6 to 4.5. More preferably, it is 1.8 to 3.5, and more preferably 1.8 to 3.0. For example, the relative viscosity ηr can be increased by increasing the degree of vacuum in the melt polymerization in the post-polycondensation step of the polyamide resin described later.

[Thermal properties and low water absorption of polyamide resin]
The polyamide resin of the present invention is desired to have various thermal properties and water absorption by including a unit derived from an oxalic acid compound and a unit derived from 1,5-pentanediamine and 2-methyl-1,5-pentanediamine. Range.

  The melting point Tm of the polyamide resin of the present invention is preferably 200 ° C. or higher, more preferably 200 to 300 ° C. By having such a melting point, it has high heat resistance, and it is not necessary to use an excessively high temperature condition in which thermal decomposition occurs and inhibits high molecular weight in the melt polymerization of the polyamide resin described later. (Increase the relative viscosity). The melting point Tm of the polyamide resin of the present invention means an endothermic peak temperature in a DSC chart measured by a differential scanning calorimetry at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere unless otherwise specified.

  In addition, from the viewpoint of having higher crystallinity, the heat of fusion ΔHm calculated from the endothermic peak area in the DSC chart measured by the differential scanning calorimetry at a heating rate of 10 ° C./min in a nitrogen atmosphere is preferably 30 J / g or more, more preferably 32 J / g or more, further preferably 35 J / g or more, further preferably 40 J / g or more, and particularly preferably 50 J / g or more. . Since the polyamide resin of the present invention has high crystallinity and excellent heat resistance, the mechanical properties and heat resistance of the molded product are also excellent.

The crystallization temperature Tc of the polyamide resin of the present invention is preferably 270 ° C. or less, more preferably 170 to 270 ° C., and more preferably 180 to 260 ° C. from the viewpoint of achieving both excellent melt moldability and high crystallinity. Further preferred. The crystallization temperature Tc of the polyamide resin of the present invention means an exothermic peak temperature in a DSC chart measured by a differential scanning calorimetry at a temperature rising rate of 10 ° C./min in a nitrogen atmosphere unless otherwise specified.
Unlike the conventional polyoxamide resin, the polyamide resin of the present invention does not impair melt moldability while having high crystallinity. From the viewpoint of having better melt moldability, the temperature difference between the crystallization temperature Tc and the melting point Tm of the polyamide resin of the present invention is preferably 24 ° C. or higher, more preferably more than 24 ° C., further preferably 30 ° C. or higher. Can be.

  Further, the absolute value of the crystallization heat amount ΔHc of the polyamide resin of the present invention calculated from the exothermic peak area in the DSC chart measured by the differential scanning calorimetry at a heating rate of 10 ° C./min in a nitrogen atmosphere is high crystallinity. From the viewpoint of having the above, it is preferably 30 J / g or more, more preferably 35 J / g or more, and particularly preferably 40 J / g or more. Since the polyamide resin of the present invention has high crystallinity and excellent heat resistance, the mechanical properties and heat resistance of the molded product are also excellent.

  The saturated water absorption rate of the polyamide resin of the present invention is preferably 3.5 or less, more preferably in the range of 1.0 to 3.0, and still more preferably, from the viewpoint of reducing changes in physical properties and changes in dimensions due to water absorption. It is in the range of 1.5 to 2.5. Although the polyamide resin of the present invention has high crystallinity and moldability as described above, it does not impair the low water absorption observed in conventional polyoxamide resins. In addition, unless otherwise indicated, the measurement of the saturated water absorption rate of the polyamide resin of this invention is based on the measuring method as described in the Example mentioned later.

[Production of polyamide resin]
The polyamide resin of the present invention can be produced by any method known as a method for producing a polyamide resin. From the viewpoint of high molecular weight and productivity, diamine and oxalic acid diester are preferably batch-processed. It can be obtained by a polycondensation reaction in a formula or continuous manner.
Specifically, it can be obtained by (i) a two-stage polymerization method or (ii) a pressure polymerization method comprising a pre-polycondensation step and a post-polycondensation step. Specifically, the synthesis is preferably performed by the polymerization method (i) or (ii) as shown by the following operation.

(I) Two-stage polymerization method: pre-polycondensation step First, after the inside of the reactor was purged with nitrogen, a diamine component (1,5-pentanediamine and 2-methyl-1,5-pentanediaminediamine) and a dicarboxylic acid component (oxalic acid) Compound). When mixing, a solvent in which both the diamine component and the dicarboxylic acid component are soluble may be used. Solvents in which both the diamine component and the dicarboxylic acid component are soluble include aromatic hydrocarbon solvents such as toluene and xylene, halogenated hydrocarbon solvents such as trichlorobenzene, phenol solvents such as phenol and cresol, 2, 2 , 2-trifluoroethanol and the like, and preferred solvents include toluene. For example, after heating the toluene solution which melt | dissolved the diamine component to 50 degreeC, a dicarboxylic acid component is added with respect to this.

  In the two-stage polymerization method, the charging ratio of the dicarboxylic acid component and the diamine component is preferably dicarboxylic acid component / diamine component and 0.8 to 1.5 (molar ratio) from the viewpoint of increasing the molecular weight. More preferably, it is .91 to 1.1 (molar ratio), and even more preferably 0.99 to 1.01 (molar ratio).

  The charging ratio (molar ratio) of 1,5-pentanediamine and 2-methyl-1,5-pentanediamine, which is a diamine component, is the unit derived from 1,5-pentanediamine in the polyamide resin of the present invention. It means the molar ratio of units derived from 2-methyl-1,5-pentanediamine. Therefore, the charging ratio of 1,5-pentanediamine and 2-methyl-1,5-pentanediamine is also 5:95 to 90:10 (molar ratio) so that the molar ratio falls within a desired range. Is more preferably 10:90 to 80:20 (molar ratio), and even more preferably 15:85 to 80:20 (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.

(I) Two-stage polymerization method: 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 raising process, the final ultimate temperature of the pre-polycondensation step, that is, preferably from 80 to 150 ° C., is finally preferably from 215 to 350 ° C., more preferably from 225 to 350 ° C., further preferably from 230 to 345 ° C. It is preferable to carry out the reaction while preferably reaching a temperature range of 230 to 340 ° C., preferably 1 to 8 hours, more preferably 2 to 6 hours, including the temperature raising time. Furthermore, in the post-polymerization step, polymerization can be performed under reduced pressure as necessary. A preferable final ultimate pressure in the case of performing the vacuum polymerization is 0.1 MPa to 13.3 Pa.

(Ii) Pressurized polymerization method First, the diamine component is placed in a pressure-resistant vessel and purged with nitrogen, and then heated to the reaction temperature under a sealing pressure. Thereafter, the oxalic acid compound is injected into the pressure vessel while maintaining the sealed pressure state at the reaction temperature, and the polycondensation reaction is started. The reaction temperature is not particularly limited as long as the polyamide produced by the reaction of the diamine component and the dicarboxylic acid component can maintain a slurry or solution state and does not thermally decompose. For example, in the case of the polyoxamide resin using 1,5-pentanediamine and 2-methyl-1,5-pentanediamine and dibutyl oxalate as raw materials of the present invention, the reaction temperature is preferably 150 to 250 ° C.

  In the pressure polymerization method, the charging ratio of the dicarboxylic acid component and the diamine component is preferably dicarboxylic acid component / diamine component and 0.8 to 1.5 (molar ratio) from the viewpoint of increasing the molecular weight. More preferably, it is .91 to 1.1 (molar ratio), and even more preferably 0.99 to 1.01 (molar ratio).

  The charging ratio (molar ratio) of 1,5-pentanediamine and 2-methyl-1,5-pentanediamine, which is a diamine component, is the unit derived from 1,5-pentanediamine in the polyamide resin of the present invention. It means the molar ratio of units derived from 2-methyl-1,5-pentanediamine. Therefore, the charging ratio of 1,5-pentanediamine and 2-methyl-1,5-pentanediamine is also 5:95 to 90:10 (molar ratio) so that the molar ratio falls within a desired range. Is more preferably 10:90 to 80:20 (molar ratio), and even more preferably 15:85 to 80:20 (molar ratio).

  While keeping the inside of the pressure vessel thus charged in a sealed pressure state, the temperature is raised to a temperature not lower than the melting point of the polyamide resin and not pyrolyzed. For example, in the case of the polyoxamide resin using 1,5-pentanediamine and 2-methyl-1,5-pentanediamine and dibutyl oxalate as raw materials of the present invention, the melting point is 200 to 300 ° C., and therefore 220 ° C. to 340 ° C. The temperature is preferably raised to 230 ° C to 330 ° C, more preferably 240 ° C to 325 ° C. The pressure in the pressure vessel until reaching the predetermined temperature is adjusted to approximately 0.1 MPaG or more, preferably 0.2 MPaG to 1 MPaG from the saturated vapor pressure of the alcohol to be generated. After reaching the predetermined temperature, the pressure is released while distilling off the produced alcohol, and the polycondensation reaction is continued under normal pressure nitrogen flow or reduced pressure as necessary. A preferable final ultimate pressure in the case of performing the vacuum polymerization is 0.1 MPa to 13.3 Pa.

[Optional ingredients]
The polyamide resin of the present invention may contain units derived from other dicarboxylic acid components other than the oxalic acid compound as long as the effects of the present invention are not impaired. Therefore, in the production of the polyamide resin of the present invention, in addition to the oxalic acid compound, other dicarboxylic acids may be used in combination as the dicarboxylic acid component. Examples of such other dicarboxylic acid components 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; terephthalic acid and isophthalic acid 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, dibenzoic acid, 4 , 4′-oxydibenzoic acid, diphenylmethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′- Carboxylic acids, can be mentioned aromatic dicarboxylic acids such as 4,4'-biphenyl dicarboxylic acid, the more of these one or two, in addition to the oxalate compound can also be added during the polycondensation reaction. Furthermore, polyvalent carboxylic acids such as trimellitic acid, trimesic acid and pyromellitic acid can be used within a range where molding is possible.

  When other dicarboxylic acid components are used, the proportion thereof is 25 mol% or less, preferably 15 mol% or less, more preferably 10 mol% or less, still more preferably 5 mol% or less, based on the oxalic acid compound. 0 mol% (that is, the dicarboxylic acid component is composed only of an oxalic acid compound) is particularly preferred. The molar ratio of the other dicarboxylic acid component to the oxalic acid compound also means the molar ratio of the unit derived from the oxalic acid compound and the unit derived from the other dicarboxylic acid component in the polyamide resin.

  Similarly, the polyamide resin of the present invention may contain units derived from other diamine components other than 1,5-pentanediamine and 2-methyl-1,5-pentanediamine as long as the effects of the present invention are not impaired. . Therefore, in the production of the polyamide resin of the present invention, other diamines may be used in combination in addition to 1,5-pentanediamine and 2-methyl-1,5-pentanediamine as the diamine component. Examples of such other diamine components include ethylenediamine, propylenediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 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 Aliphatic diamines such as -1,6-hexanediamine and 5-methyl-1,9-nonanediamine; Alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine and isophoronediamine; p-phenylenediamine, m-phenylenediamine, p -Xylylenediamine, m-xylylenediamine, 4,4'-diaminodi And aromatic diamines such as phenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, and the like. In addition to 1,5-pentanediamine, it can also be added during the polycondensation reaction.

  When other diamine components are used, the proportion thereof is 25 mol% or less, preferably 15 mol% or less, preferably 10 mol% based on 1,5-pentanediamine and 2-methyl-1,5-pentanediamine. The following is more preferable, 5 mol% or less is further preferable, and 0 mol% (that is, the diamine component is composed of 1,5-pentanediamine and 2-methyl-1,5-pentanediamine only) is further preferable. The molar ratio of other diamine components to 1,5-pentanediamine and 2-methyl-1,5-pentanediamine is 1,5-pentanediamine and 2-methyl-1,5-pentane in the polyamide resin. The molar ratio of the unit derived from a diamine and the unit derived from another diamine component is also meant.

  The polyamide resin of the present invention can be mixed with other polyoxamides, polyamides such as aromatic polyamides, aliphatic polyamides, and alicyclic polyamides within a range not impairing the effects of the present invention.

  The polyamide resin of the present invention can be further blended with thermoplastic polymers other than polyamide, elastomers, fillers, reinforcing fibers, and various additives.

  Furthermore, in the polyamide resin of the present invention, if necessary, a stabilizer such as a copper compound, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, a crystallization accelerator, Glass fibers, plasticizers, lubricants and the like can be added during or after the polycondensation reaction.

[Molding and molded products]
As the molding method of the polyamide resin of the present invention, all known molding methods applicable to conventional polyamides such as injection, extrusion, hollow, press, roll, foaming, vacuum / pressure air, and stretching can be used. It can be processed into films, sheets, molded articles, fibers and the like by the method.

  The molded product of the polyamide resin of the present invention includes various molded products, sheets, films, pipes, tubes, monofilaments, fibers, containers, etc. for which conventional polyamide resin molded products have been used, automobile members, computers and related equipment, optical It can be used for a wide range of applications such as equipment members, electrical / electronic equipment, information / communication equipment, precision equipment, civil engineering / building supplies, medical supplies, and household goods. Further, it can be expected to be used as a fuel peripheral member (fuel tube, fuel tank, etc.) of an automobile.

[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. The relative viscosity, melting point, heat of fusion, crystallization temperature, heat of crystallization, and saturated water absorption, and evaluation of chemical resistance, hydrolysis resistance, and ethanol barrier properties in the examples are as follows. went.

(1) Relative viscosity ηr
ηr is measured at 25 ° C. using an Ostwald viscometer, using a 96% sulfuric acid solution (concentration: 1.0 g / dl) of the polyamide resin obtained in Examples 1-4 and Comparative Examples 1-4. did.

(2) Melting point Tm, heat of fusion ΔHm, crystallization temperature Tc and heat of crystallization ΔHc
Tm and Tc were measured in a nitrogen atmosphere using a PYRIS Diamond DSC manufactured by PerkinELmer.
Tm and Tc of the polyamide resins obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were heated from 30 ° C. to 310 ° C. at a rate of 10 ° C./min (referred to as temperature rising first run), and 310 ° C. The temperature was lowered to 30 ° C. at a rate of 10 ° C./min (referred to as a temperature-decreasing first run), and then increased to 310 ° C. at a rate of 10 ° C./min (referred to as a temperature-rising second run). .
From the obtained DSC chart, the exothermic peak temperature of the temperature drop first run was set as the crystallization temperature Tc, and the crystallization heat amount ΔHc was calculated from the exothermic peak area and expressed as an absolute value. Further, the endothermic peak temperature of the temperature-increased second run was defined as the melting point Tm, and the heat of fusion ΔHm was calculated from the endothermic peak area.

(3) Film shaping | molding Film shaping | molding was performed with the following method with respect to the polyamide resin of Examples 1-4 and Comparative Examples 1-7 using the Toho Machinery company vacuum press machine TMB-10.
The polyamide resin obtained in each Example and Comparative Example was melted by heating at 260 to 310 ° C. for 3 minutes under a reduced pressure atmosphere of 500 to 700 Pa, and then pressed at 10 MPa for 1 minute to form a film. Next, after the reduced-pressure atmosphere was returned to normal pressure, it was cooled and crystallized at room temperature and 5 MPa for 3 minutes to obtain a film (thickness: 0.25 mm). Here, the moldability of the sample from which the film was obtained was evaluated as acceptable, and the moldability of the sample in which thermal decomposition occurred and a film-like molded product was not obtained was evaluated as unacceptable.

(4) Saturated water absorption Films obtained by molding the polyamide resins of Examples 1 to 4 and Comparative Examples 5 to 7 under the conditions of (3) above (dimensions: 20 mm × 10 mm, thickness: 0.25 mm; weight: about 0.00. 05 g) was immersed in ion exchange water at 23 ° C., the film was taken out every predetermined time, 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 reaching saturation by the following formula (1).

(5) Chemical resistance Film obtained by molding the polyamide resin of Example 2 and Comparative Examples 5 to 7 under the above condition (3) (dimensions: 20 mm × 10 mm, thickness: 0.25 mm; weight: about 0.05 g ) In each chemical (concentrated hydrochloric acid, 64% sulfuric acid, 30% aqueous sodium hydroxide, 5% aqueous potassium permanganate, and benzyl alcohol) for 7 days, and then the weight residual ratio (%) and appearance of the film The change of was observed.
Concentrated hydrochloric acid, 64% sulfuric acid, 30% aqueous sodium hydroxide, and 5% aqueous potassium permanganate were immersed at 23 ° C., and benzyl alcohol was immersed at 50 ° C.

(6) Hydrolysis resistance A film (dimensions: 20 mm × 10 mm, thickness: 0.25 mm; weight: about 0.05 g) obtained by molding the polyamide resins of Example 2 and Comparative Examples 5 and 6 under the conditions of (3) above. ) Was placed in an autoclave and treated in water, 0.5 mol / l sulfuric acid, and 1 mol / l sodium hydroxide aqueous solution at 121 ° C. for 60 minutes, respectively, and the weight residual ratio (%) and appearance change were observed.

(7) Ethanol barrier property With respect to a film (dimensions: diameter 60 mm, thickness: 0.13 mm) obtained by molding the polyamide resin of Example 2 and Comparative Examples 5 and 6 under the above-mentioned conditions (3), GTR Tech Co., Ltd. Using a differential pressure type gas / vapor / liquid permeability measuring device (GTR-30XAUB), the vapor of ethanol is brought into contact with the film at 60 ° C., and the amount of ethanol passing through the film is measured. The permeation coefficient at this point was determined, and the ethanol barrier property was evaluated.

[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. 700 ml of used toluene, 40.9 g (0.400 mol) of 1,5-pentanediamine, and 11.6 g (0.0998 mol) of 2-methyl-1,5-pentanediamine were charged. After this separable flask was placed in an oil bath and heated to 50 ° C., 101 g (0.499 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 transferred to a salt bath maintained at 305 ° C. under a nitrogen stream of 50 ml / min, and the inside of the container was depressurized to about 66.5 Pa. Reacted for 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.

[Example 2]
5L equipped with a stirrer, thermometer, torque meter, pressure gauge, nitrogen gas inlet, pressure outlet, polymer outlet, and raw material inlet with a raw material feed pump directly connected by SUS316 piping of 1/8 inch diameter A pressure vessel is charged with 256 g (2.51 mol) of 1,5-pentanediamine and 292 g (2.51 mol) of 2-methyl-1,5-pentanediamine, and the inside of the pressure vessel is added to 3.0 MPaG with nitrogen gas. Then, nitrogen gas was released to normal pressure, and the system was heated up under a sealing pressure. After setting the internal temperature to 190 ° C. over 20 minutes, 1015 g (5.02 mol) of dibutyl oxalate was injected into the reaction vessel at a flow rate of 65 ml / min by a raw material feed pump. The internal pressure in the pressure vessel immediately after injection of the entire amount increased to 0.65 MPaG by 1-butanol generated by the polycondensation reaction, and the internal temperature increased to 197 ° C.
Distillation of butanol generated immediately after injection was started, and the internal temperature was raised to 270 ° C. over 2 hours while maintaining the internal pressure at 0.50 MPaG. Immediately after the internal temperature reached 270 ° 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 280 ° C. over 1 hour, and the temperature was maintained at 280 ° C. for 1 hour. Thereafter, the stirring was stopped, the inside of the system was pressurized to 3 MPaG with nitrogen and allowed to stand for 10 minutes, then the pressure was released to an internal pressure of 0.5 MPaG, and the polyamide resin was extracted from the lower part of the pressure vessel. The extracted polyamide resin was immediately cooled with water and collected.

[Example 3]
Using a separable flask having a volume of 300 ml in the pre-polycondensation step, 120 ml of dehydrated toluene, 2.05 g (0.0201 mol) of 1,5-pentanediamine, 9.33 g of 2-methyl-1,5-pentanediamine (0.0803 mol) and 20.3 g (0.100 mol) of dibutyl oxalate were added and reacted at 250 ° C. for 4 hours in the post-polycondensation step. Obtained.

[Example 4]
1,5-pentanediamine 51.3 g (0.502 mol), 2-methyl-1,5-pentanediamine 525 g (4.52 mol), and dibutyl oxalate 1019 g (5.04 mol) were used at 0.50 MPaG. Was performed in the same manner as in Example 2 except that the temperature was raised to 240 ° C. and the temperature was raised to 250 ° C. under a nitrogen stream to obtain a polyamide resin.

[Comparative Example 1]
In the pre-polycondensation step, a separable flask having a volume of 300 ml was used, 150 ml of dehydrated toluene, 5.39 g (0.0464 mol) of 1,6-hexanediamine, and 5.39 g of 2-methyl-1,5-pentanediamine. (0.0464 mol) and 18.8 g (0.0928 mol) of dibutyl oxalate were added and reacted at 285 ° C. for 4 hours in the post-polycondensation step. Obtained.

[Comparative Example 2]
Using 117 g (1.01 mol) of 1,6-hexanediamine, 469 g (4.04 mol) of 2-methyl-1,5-pentanediamine, and 1021 g (5.05 mol) of dibutyl oxalate, the pressure was 230 under 0.50 MPaG. A polyamide resin was obtained in the same manner as in Example 2 except that the temperature was raised to 0 ° C. and the temperature was raised to 240 ° C. under a nitrogen stream.

[Comparative Example 3]
In the pre-polycondensation step, a separable flask having a volume of 300 mL was used, 150 ml of dehydrated toluene, 11.5 g (0.0990 mol) of 2-methyl-1,5-pentanediamine, and 20.0 g (0.0989) of dibutyl oxalate. In the post-polycondensation step, a reaction was carried out in the same manner as in Example 1 except that the reaction was carried out at 230 ° C. for 4 hours to obtain a polyamide resin.

[Comparative Example 4]
In the pre-polycondensation step, a separable flask having a volume of 300 mL was used, and 150 ml of dehydrated toluene, 10.3 g (0.101 mol) of 1,5-pentanediamine and 20.4 g (0.101 mol) of dibutyl oxalate were charged. In the post-polycondensation step, a reaction was carried out in the same manner as in Example 1 except that the reaction was carried out at 310 ° C. for 4 hours to obtain a polyamide resin. The resulting product was a yellow brittle polymer and could not be pressed.

[Comparative Example 5]
In the pre-polycondensation step, a separable flask having a volume of 300 mL was used, 150 ml of dehydrated toluene, 13.6 g (0.086 mol) of 1,9-nonanediamine, 2.4 g of 2-methyl-1,8-octanediamine ( 0.015 mol) and 20.4 g (0.101 mol) of dibutyl oxalate were added and reacted at 270 ° C. for 4 hours in the post-polycondensation step to obtain a polyamide resin by reacting in the same manner as in Example 1. It was. Using this polyamide resin, a film (thickness: 0.25 mm) was molded under the condition (3). The film was evaluated for saturated water absorption, chemical resistance, hydrolysis resistance, and ethanol barrier properties.

[Comparative Example 6]
Instead of the polyamide resin of the present invention, a film (thickness: 0.25 mm) was molded under the condition (3) above using nylon 6 (UBE Nylon 1015B, manufactured by Ube Industries). The obtained nylon 6 film was a colorless transparent tough film. The film was evaluated for saturated water absorption, chemical resistance, hydrolysis resistance, and ethanol barrier properties.

[Comparative Example 7]
Instead of the polyamide resin of the present invention, a film (thickness: 0.25 mm) was molded under the condition (3) above using nylon 66 (manufactured by Ube Industries, UBE nylon 2020B). The obtained nylon 66 film was a colorless transparent tough film. The film was evaluated for saturated water absorption and chemical resistance.

  Results of measurement of diamine composition, relative viscosity ηr, melting point Tm, heat of fusion ΔHm, crystallization temperature Tc and crystallization heat amount ΔHc of the polyamide resins obtained in Examples 1 to 4 and Comparative Examples 1 to 4, and temperature difference ( Table 1 shows the results of evaluation of Tm-Tc) and moldability. Table 2 shows the results of measurement of the saturated water absorption of the films obtained from the polyamide resins of Examples 1 to 4 and Comparative Examples 5 to 7, and the evaluation results of chemical resistance, hydrolysis resistance, and ethanol barrier properties. Shown in

  From Table 1, the polyamide resin of the present invention (Examples 1 to 4) has a high heat resistance (melting point Tm) equivalent to that of the conventional polyoxamide resin (Comparative Examples 1 to 4) while having a high crystallization heat amount ΔHc. It can be seen that the moldability (temperature difference (Tm−Tc) and moldability) is ensured.

  Furthermore, from Table 2, the molded product (film) obtained by the polyamide resin of the present invention has excellent chemical resistance, hydrolysis resistance and ethanol barrier properties as well as low water absorption superior to conventional products. I understand that.

  The polyamide resin of the present invention is a polyoxamide resin that has a high heat of crystallization, that is, high crystallinity, is excellent in low water absorption, chemical resistance, hydrolysis resistance, ethanol barrier property, etc., and has excellent moldability. is there. Therefore, it can be suitably used as a molding material for industrial materials, industrial materials, household goods and the like. For example, various molded products, sheets, films, pipes, tubes, monofilaments, fibers, containers, etc., automobile members, computers and related equipment, optical equipment members, electrical / electronic equipment, information / communication equipment, precision equipment, civil engineering / building supplies It can be used for a wide range of applications such as medical supplies and household products. The polyamide resin of the present invention can be expected to be used as a fuel peripheral member (fuel tube, fuel tank, etc.) of an automobile.

Claims (6)

  A polyamide resin comprising a unit derived from a dicarboxylic acid component and a unit derived from a diamine component, wherein the dicarboxylic acid component contains an oxalic acid compound, and the diamine component is 1,5-pentanediamine and 2-methyl-1,5-pentane. Polyamide resin containing diamine.   The polyamide resin according to claim 1, wherein the heat of fusion measured by a differential scanning calorimetry at a heating rate of 10 ° C / min in a nitrogen atmosphere is 32 J / g or more.   The polyamide resin according to claim 1 or 2, wherein the heat of crystallization measured by a differential scanning calorimetry at a temperature drop rate of 10 ° C / min in a nitrogen atmosphere is 35 J / g or more.   The polyamide resin according to any one of claims 1 to 3, wherein a melting point measured by a differential scanning calorimetry at a rate of temperature increase of 10 ° C / min in a nitrogen atmosphere is 200 ° C or higher.   There is a temperature difference between the crystallization temperature measured by the differential scanning calorimetry at a temperature decrease rate of 10 ° C./min in a nitrogen atmosphere and the melting point measured by the differential scanning calorimetry at a temperature increase rate of 10 ° C./min in a nitrogen atmosphere. The polyamide resin according to any one of claims 1 to 4, which exceeds 24 ° C.   The polyamide resin according to any one of claims 1 to 5, wherein a molar ratio of 1,5-pentanediamine and 2-methyl-1,5-pentanediamine is 10:90 to 80:20.