polyamide

Abstract

This invention relates to polyamides. The invention provides polyamides with excellent heat resistance, water resistance, and impact resistance. The invention is a polyamide having structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines, wherein the total hydroxyl and ester groups are 0.40 to 0.70 mol% relative to 100 mol% of the structural units derived from dicarboxylic acids.

Description

[0001] This invention application is a divisional application of PCT patent application PCT / JP2015 / 001246, filed on March 6, 2015, entitled "Polyamide". The parent application number in China is 201580018094.8. Technical Field

[0002] This invention relates to polyamides with excellent heat resistance, water resistance and impact resistance. Background Technology

[0003] Crystalline polyamides, such as nylon 6 and nylon 66, have long been widely used as fibers for clothing, industrial materials, or general engineering plastics due to their excellent properties and ease of melt molding.

[0004] However, on the other hand, problems such as insufficient heat resistance and poor dimensional stability due to water absorption have also been pointed out. In particular, for electrical and electronic fields that require heat resistance for reflow soldering due to the development of surface mount technology (SMT) in recent years, or for automotive engine room components where the requirements for heat resistance are increasing year by year, it is difficult to use the polyamides of the past. The demand for polyamides with better heat resistance, dimensional stability, mechanical properties, and physicochemical properties is increasing.

[0005] In response to this social demand, various polyamides containing modified PA6-T, PA9-T and other aromatic dicarboxylic acid units (so-called semi-aromatic polyamides) have been proposed, which have superior heat resistance and chemical resistance compared with the previous aliphatic polyamides such as polyamide 6 and polyamide 66 (see Patent Documents 1 and 2).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 59-53536

[0009] Patent document 2: Japanese Patent Application Publication No. 7-228689. Summary of the Invention

[0010] The problem the invention aims to solve

[0011] However, while semi-aromatic polyamides not only have excellent heat resistance, especially their resistance to polar solvents such as water and alcohols, which is superior to that of previous aliphatic polyamides, they also have the problem of poor impact resistance.

[0012] means for solving problems

[0013] The inventors conducted repeated and in-depth research and found that polyamides mainly composed of aromatic dicarboxylic acid units and aliphatic diamine units, and containing hydroxyl and ester groups in specific amounts relative to the dicarboxylic acid units, exhibit excellent heat resistance, water resistance, and impact resistance. Based on these insights, the inventors conducted further research and thus completed this invention.

[0014] That is, the present invention relates to the following technical solutions:

[0015] [1] Polyamide, which is a polyamide having structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines, wherein the total number of hydroxyl and ester groups is 0.40 to 0.70 mol% relative to 100 mol% of the structural units derived from dicarboxylic acids.

[0016] [2] According to the polyamide described in [1] above, the content of structural units derived from aromatic dicarboxylic acids is 25-52 mol%, and the content of structural units derived from aliphatic diamines is 30-53 mol% (wherein the total content of structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines does not exceed 100 mol%).

[0017] [3] According to the polyamide of [1] or [2] above, wherein the aromatic dicarboxylic acid is terephthalic acid;

[0018] [4] The polyamide according to any one of [1] to [3] above, wherein the aliphatic diamine is an aliphatic diamine with 4 to 12 carbon atoms;

[0019] [5] According to the polyamides described above [1] to [4], the aliphatic diamine with 4 to 12 carbon atoms is selected from at least one of 1,6-hexanediamine, 2-methyl-1,5-pentanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,10-decanediamine;

[0020] [6] The polyamide according to any one of [1] to [5] above further contains 0.5 to 4 mol% of structural units derived from the capping agent; and

[0021] [7] The method for manufacturing polyamide according to any one of [1] to [6] above includes the following steps:

[0022] Step (1) involves supplying an aqueous solution of nylon salt with a concentration of 50-90% by mass and a liquid temperature of 100-180°C to the reactor; and

[0023] The polymerization step (2) is carried out under the following conditions: the liquid temperature in the reactor is 230~260℃, the pressure in the reactor is 0.7~0.9 times the saturated vapor pressure of water at that liquid temperature, and the average residence time in the reactor is less than 1 hour.

[0024] The effects of the invention

[0025] According to the present invention, a polyamide with excellent heat resistance, water resistance and excellent impact resistance, and a method for manufacturing the polyamide are provided. Detailed Implementation

[0026] The present invention will now be described in detail.

[0027] The monomer units constituting the polyamide used in this invention comprise structural units derived from aromatic dicarboxylic acids (hereinafter referred to as "aromatic dicarboxylic acid units"). It should be noted that aromatic dicarboxylic acids refer to compounds in which two carboxyl groups are directly covalently bonded to an aromatic ring such as a benzene ring or naphthalene ring. Furthermore, from the perspective of obtaining polyamides with excellent water resistance, impact resistance, high melting point, high glass transition temperature, and excellent heat resistance, the content of aromatic dicarboxylic acid units is preferably 25-52 mol%, more preferably 30-51 mol%, and even more preferably 35-50 mol%. The method for evaluating the content of aromatic dicarboxylic acid units is as described in the examples below.

[0028] Examples of aromatic dicarboxylic acid units include those derived from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylene dioxydiacetic acid, 1,3-phenylene dioxydiacetic acid, biphenyl acid, 4,4'-diphenyl ether dicarboxylic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenyl sulfone-4,4'-dicarboxylic acid, and 4,4'-biphenyl dicarboxylic acid. Among these, the terephthalic acid unit exhibits higher heat resistance and water resistance, and is therefore preferred.

[0029] The polyamide of the present invention, without impairing the effects of the present invention, may further include dicarboxylic acid units other than aromatic dicarboxylic acid units as dicarboxylic acid units. Examples of dicarboxylic acid units other than aromatic dicarboxylic acid units include, for example, aliphatic dicarboxylic acids such as malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyl adipic acid, trimethyl adipic acid, pimelic acid, 2,2-dimethylglutaric acid, 2,2-diethylsuccinic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid; and alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. One or more of these units may be included. The polyamide of the present invention, within the range of melt-forming capability, may also include units derived from polycarboxylic acids such as benzotriglyceride, benzopyridinium trioxide, and benzopyridinium tetracarboxylic acid.

[0030] The monomer units constituting the polyamide used in this invention include structural units derived from aliphatic diamines (hereinafter referred to as "aliphatic diamine units"). Furthermore, from the perspective of obtaining polyamides with excellent impact resistance and water resistance, the content of aliphatic diamine units is preferably 30-53 mol%, more preferably 35-52 mol%, and even more preferably 38-51 mol%. As aliphatic diamine units, aliphatic diamine units with 4 to 12 carbon atoms are preferred. The method for evaluating the content of aliphatic diamine units is as described in the examples below.

[0031] Examples of aliphatic diamine units with 4 to 12 carbon atoms include, for example, straight-chain aliphatic diamines such as 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine; and 1-butyl-1,2-ethylenediamine, 1,1-dimethyl-1,4-butanediamine, 1,2-ethyl-1,4-butanediamine, etc. -Dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl 1,6-Hexanediamine, 2,4,4-Trimethyl-1,6-Hexanediamine, 2,4-Diethyl-1,6-Hexanediamine, 2,2-Dimethyl-1,7-Heptanediamine, 2,3-Dimethyl-1,7-Heptanediamine, 2,4-Dimethyl-1,7-Heptanediamine, 2,5-Dimethyl-1,7-Heptanediamine, 2-Methyl-1,8-Octadiamine, 3-Methyl-1,8-Octadiamine, 4-Methyl-1,8-Octadiamine, 1,3-Dimethyl-1,8-Octadiamine The derivative units of branched aliphatic diamines such as diamines, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1,8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine may include one or more of these.

[0032] From the viewpoint of excellent heat resistance and water resistance, the diamine used as the above-mentioned aliphatic diamine unit is preferably selected from at least one of 1,6-hexanediamine, 2-methyl-1,5-pentanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,10-decanediamine, more preferably 1,9-nonanediamine and / or 2-methyl-1,8-octanediamine.

[0033] When 1,9-nonanediamine and 2-methyl-1,8-octanediamine are used together as diamines, the preferred molar ratio is 1,9-nonanediamine:2-methyl-1,8-octanediamine = 45:55 to 90:10.

[0034] The diamine unit described above may also include other diamine units besides aliphatic diamine units with 4 to 12 carbon atoms, without impairing the effects of the present invention. Examples of such other diamine units include, for instance, units derived from aliphatic diamines such as ethylenediamine, 1,2-propanediamine, and 1,3-propanediamine; alicyclic diamines such as cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, norbornene dimethylamine, and tricyclosilane dimethylamine; and aromatic diamines such as p-phenylenediamine, m-phenylenediamine, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenyl ether. One or more of these units may be included.

[0035] Furthermore, the polyamide of the present invention may also contain lactam or aminocarboxylic acid units without impairing the effects of the present invention. Specifically, units derived from lactams such as ε-caprolactam and ω-laurolactam, and aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid can be listed.

[0036] In the polyamide of the present invention, the monomer unit preferably contains 4 mol% or less (excluding 0 mol%) of units derived from the end-capping agent, more preferably 0.5 to 4 mol%, and even more preferably 0.7 to 2.5 mol%. When the units derived from the end-capping agent are contained in the above proportions, polyamides with superior melt-forming properties and other physical properties can be obtained. The method for evaluating the content of units derived from the end-capping agent is as described in the examples below.

[0037] As capping agents, monofunctional compounds that react with terminal amino or terminal carboxyl groups can be used. Examples include acid anhydrides, monoisocyanates, monoacyl halides, monoesters, and monoalcohols. From the viewpoints of reactivity and capping stability, monocarboxylic acids are preferred as capping agents for terminal amino groups, and monoamines are preferred as capping agents for terminal carboxyl groups. Furthermore, from the viewpoints of ease of processing, monocarboxylic acids are more preferred as capping agents.

[0038] As for monocarboxylic acids used as end-capping agents, there are no particular limitations as long as they are reactive with amino groups. Examples include aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, octanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, tervaric acid, and isobutyric acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthoic acid, β-naphthoic acid, methylnaphthoic acid, and phenylacetic acid; and any mixtures thereof. Among these, from the viewpoints of reactivity, end-capping stability, and price, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, octanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, and benzoic acid are preferred.

[0039] As for the monoamines used as capping agents, there are no particular limitations as long as they are reactive with carboxyl groups. Examples include aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine; and any mixtures thereof. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferred from the viewpoints of reactivity, high boiling point, capping stability, and price.

[0040] In the polyamide of the present invention, the total content of hydroxyl and ester groups relative to 100 mol% of the structural units derived from dicarboxylic acid units is 0.40 to 0.70 mol%, preferably 0.45 to 0.60 mol%. By including hydroxyl and ester groups in the above proportions, a polyamide with excellent impact resistance can be obtained. The method for evaluating the content of hydroxyl and ester groups is as described in the examples below.

[0041] In the polyamide of the present invention, the content (mol%) of hydroxyl groups in 100 mol% of structural units derived from dicarboxylic acid units is preferably 0.05 to 0.40 mol%, more preferably 0.08 to 0.35 mol%, and even more preferably 0.10 to 0.30 mol%.

[0042] In the polyamide of the present invention, in 100 mol% of the structural unit derived from the dicarboxylic acid unit, the content of ester group (mol%) is preferably 0.5 to 12 times, more preferably 1.0 to 5.0 times, and even more preferably 1.5 to 3.0 times, of the content of hydroxyl group (mol%).

[0043] Methods for introducing hydroxyl groups into polyamides include (1) adding a diol or amino alcohol at any stage of polyamide polymerization; and (2) conducting polyamide polymerization in the presence of water at the beginning, thereby hydrolyzing the amino group, which is mainly derived from a diamine, to generate hydroxyl groups. Method (2) is preferred. Examples of diols include 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol. Examples of amino alcohols include 4-amino-1-butanol, 5-amino-1-pentanol, 6-amino-1-hexanol, 7-amino-1-heptanol, 8-amino-1-octanol, 9-amino-1-nonanol, and 10-amino-1-decanol. Furthermore, by reacting the hydroxyl groups thus generated with carboxyl groups, which are mainly derived from dicarboxylic acids, present in the polymerization system, ester groups can be generated. By appropriately controlling the addition amounts of diols and amino alcohols, as well as factors such as moisture, temperature, and time in the polymerization system during polyamide polymerization, the content of hydroxyl and ester groups relative to polyamide can be kept within the aforementioned range.

[0044] However, in the dehydration-based amidation reaction of carboxylic acids and amines, the reaction between the carboxyl groups of aromatic carboxylic acids and the amino groups of amines is slower compared to that of aliphatic carboxylic acids. Furthermore, the equilibrium reaction between amidation and hydrolysis is biased towards the reactants. Therefore, the high concentration of amino groups in the polyamide polymerization system leads to the hydrolysis of amino groups due to water added to the polymerization system as a solvent or water in the form of condensation water generated during the amidation of carboxyl and amino groups, thus easily forming hydroxyl groups. Additionally, some of these hydroxyl groups react with carboxyl groups derived from dicarboxylic acids and end-capping agents present in the polymerization system to form ester groups. When the concentration of hydroxyl and ester groups in polyamide exceeds 0.70 mol% relative to the dicarboxylic acid units, it results in polyamides with poor impact resistance. This can be attributed to factors such as impaired hydrogen bonding between amide groups in polyamide molecules, hindered interaction between the amino and carboxyl groups at the ends of the polyamide molecule, and weakened intermolecular forces. Even if the concentration of hydroxyl and ester groups in polyamide is less than 0.40 mol% relative to 100 mol% of the structural units derived from dicarboxylic acid units, the impact resistance of polyamide will decrease. This can be attributed to the fact that the strong intermolecular interactions of polyamide make it difficult for the molecular chains to mitigate impacts.

[0045] The water absorption rate of the polyamide of the present invention is not particularly limited, but from the viewpoint of excellent water resistance and ability to suppress dimensional changes caused by moisture absorption, it is preferably 6.5% or less, more preferably 5.0% or less, further preferably 4.0% or less, and particularly preferably 3.0% or less. The method for evaluating the water absorption rate is as described in the examples below.

[0046] The melting point of the polyamide of the present invention is not particularly limited, but is preferably 280~350°C, more preferably 290~345°C, and even more preferably 300~340°C. The method for evaluating the melting point is as described in the examples below.

[0047] The polyamide of this invention is not particularly limited, but regarding impact resistance, the Charpy impact value is preferably 3.0 kJ / m. 2 The above, and more preferably 3.5 kJ / m 2 The above, and more preferably 4.0 kJ / m 2 The above describes the method for evaluating Charpy impact values ​​as illustrated in the examples described later.

[0048] The weight-average molecular weight of the polyamide in this invention is not particularly limited, but is preferably 20 × 10⁻⁶. 3 ~80×10 3 More preferably 22×10 3 ~70×10 3 A further preferred size is 25×10 3 ~60×10 3 When the weight-average molecular weight is within the above-mentioned range, the polyamide of the present invention exhibits excellent melt-forming properties, and the melt-formed articles have high strength and impact resistance. The method for evaluating the weight-average molecular weight is as described in the examples below.

[0049] The polyamide of the present invention can be manufactured using any method known as a method for manufacturing polyamide, and an example of a preferred method for manufacturing the polyamide used in the present invention is shown below.

[0050] The method for manufacturing polyamide of the present invention includes the following steps: (1) supplying an aqueous solution of nylon salt with a concentration of 50-90% by mass and a liquid temperature of 100-180°C to a reactor; and (2) performing polymerization under the conditions that the liquid temperature in the reactor is 230-260°C, the pressure in the reactor is 0.70-0.90 times the saturated vapor pressure of water at the liquid temperature, and the average residence time in the reactor is less than 1 hour.

[0051] [Step (1)]

[0052] Initially, a mixture consisting of diamine, dicarboxylic acid, water, a desired capping agent, sodium hypophosphite monohydrate (described later), and a catalyst represented by phosphorous acid is heated under stirring in an atmosphere of inactive gas such as nitrogen and / or water vapor to prepare a homogeneous nylon salt aqueous solution. The heating temperature of the nylon salt aqueous solution is typically 100–180°C, preferably 120–170°C. It should be noted that the molar ratio of amino groups to carboxyl groups in the diamine, dicarboxylic acid, and capping agent is 0.98–1.05, preferably 0.99–1.03. When this molar ratio deviates from the above range, the molecular weight of the polyamide will not increase sufficiently. The amount of water can be appropriately adjusted to form a homogeneous nylon salt aqueous solution within the aforementioned heating temperature range, and the nylon salt concentration of the aforementioned aqueous solution is 50–90% by mass, preferably 60–90% by mass. Compared to components that essentially constitute polyamide, such as diamine, dicarboxylic acid, and capping agents, adding 0.01 to 0.3% by mass, preferably 0.02 to 0.2% by mass, of a catalyst can yield polyamides that are non-gelling and non-coloring.

[0053] The nylon salt aqueous solution obtained by the above operation is supplied to the first reactor at a substantially constant rate.

[0054] [Step (2)]

[0055] As suitable reaction conditions within the first reactor, the liquid temperature is 230–260°C, preferably 235–258°C. Furthermore, the pressure is 0.70–0.90 times, preferably 0.75–0.85 times, the saturated vapor pressure of water at this liquid temperature. More preferably, the liquid temperature is 230–260°C and the pressure is 0.70–0.90 times the saturated vapor pressure of water at this liquid temperature; even more preferably, the liquid temperature is 235–258°C and the pressure is 0.75–0.85 times the saturated vapor pressure of water at this liquid temperature. Additionally, the average residence time within the first reactor is typically 1 hour or less, preferably 0.8 hours or less. When the liquid temperature, pressure, and average residence time are within this range, it is easy to control the total amount of hydroxyl and ester groups relative to the dicarboxylic acid unit within the aforementioned range. The rate at which the nylon salt aqueous solution is supplied to the first reactor is not particularly limited, as long as it can be set to a constant rate within the range of the aforementioned average residence time; for example, it can be 0.5 L / h to 10 L / h. The first reactor is not particularly limited as long as it is a continuous reactor; for example, a tubular reactor or a continuous tank reactor is preferred.

[0056] [Step (3)]

[0057] The reaction solution obtained under the aforementioned conditions is introduced from the first reactor into another reactor (the second reactor) for further reaction, allowing the amidation reaction to proceed to a substantially equilibrium state. Regarding the reaction conditions within the second reactor, the liquid temperature is preferably 230–260°C, more preferably 235–258°C. Furthermore, the pressure is preferably 0.70–0.90 times, more preferably 0.75–0.85 times, the saturated vapor pressure of water at this liquid temperature. Further preferred reaction conditions are a liquid temperature of 230–260°C and a pressure of 0.70–0.90 times the saturated vapor pressure of water at this liquid temperature; particularly preferred are a liquid temperature of 235–258°C and a pressure of 0.75–0.85 times the saturated vapor pressure of water at this liquid temperature. When the amidation conversion rate, calculated by dividing the amide group concentration of the polyamide precursor obtained through this stage by the amino group concentration before the reaction, is in the range of 85% to 95%, the shift in the molar balance between carboxyl and amino groups and the decrease in polymerization rate are minimal in the subsequent polymerization stage, resulting in polyamides with smaller molecular weight distribution and superior physical properties and moldability. The second reactor is not particularly limited as long as it is a continuous reactor; for example, a tubular reactor or a continuous tank reactor is preferred. The method for evaluating the amidation conversion rate is as described in the examples below.

[0058] Next, to prepare a polyamide with the desired weight-average molecular weight (molecular weight), two methods can be listed. One method is to: (i) cool, cure, dry, and pulverize the polyamide precursor obtained by the aforementioned steps to prepare granular polyamide precursor with a mesh size of 0.1 to 3.0 mm for 50% by mass passing through a sieve, and then perform solid-phase polymerization at a temperature below the melting point of the polyamide, specifically at 200 to 270°C, for 2 to 12 hours under reduced pressure or with an inactive gas flow. A mesh size of 0.2 to 0.9 mm is more preferred for the aforementioned sieve. Another method is to: (ii) release the vapor from the gas phase of the reaction system to reduce the pressure of the prepolymerization reaction system to around 1 atmosphere, while simultaneously raising the temperature of the reaction system to above the melting point of the polyamide for melt polymerization.

[0059] Catalysts that can be used in the manufacture of polyamides include, for example, salts of phosphoric acid, phosphorous acid, or hypophosphite with metals such as potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, and antimony; ammonium salts of phosphoric acid, phosphorous acid, or hypophosphite; and ethyl, isopropyl, butyl, hexyl, isodecyl, octadecyl, decyl, and stearyl esters of phosphoric acid, phosphorous acid, or hypophosphite. Among these, sodium hypophosphite monohydrate or phosphorous acid is preferred.

[0060] The polyamide of the present invention may contain and use other components as needed, such as thermoplastic resins other than the polyamide of the present invention, compatibilizers, fillers, silane coupling agents, crystallizing nucleating agents, copper-based heat stabilizers, hindered phenolic antioxidants, hindered amine antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants and other antioxidants, dyes, pigments, ultraviolet absorbers, light stabilizers, antistatic agents, lubricants, plasticizers, slip agents, flame retardants, flame retardant additives, processing aids and other components.

[0061] The polyamide composition containing the polyamide of the present invention and the above-described components can be used to manufacture various molded articles by applying molding methods commonly used for thermoplastic resin compositions, such as injection molding, extrusion molding, compression molding, blow molding, calendering, and casting molding, depending on the type, application, and shape of the target molded article. Alternatively, molding methods combining the above-described molding methods can also be used. Furthermore, composite molded articles can be formed by bonding, fusing, or joining various materials such as thermoplastic resins, thermosetting resins, paper, metal, wood, and ceramics with the polyamide of the present invention and the above-described components.

[0062] Polyamide compositions containing the polyamides of the present invention and the above-described components have a variety of excellent properties, and therefore can be effectively used to manufacture various molded articles of any shape and purpose, such as electrical and electronic components, automotive components, industrial components, fibers, films, sheets, household goods, and other products, via the molding process described above.

[0063] As electrical and electronic components, examples include surface mount components such as FPC connectors, B2B connectors, USB connectors, memory card connectors, AV connectors, coaxial connectors, FFC connectors, switches, relays, ignition coils, CPU sockets, LED reflectors, and various camera module components; housings for IGBT modules, housings for SiC power semiconductor modules, cable and wire sheaths, fiber optic components, noise reduction gears for AV / OA instruments, automatic flashing machine components, various mobile phone components, heat-resistant gears for copiers, end caps, commutators, business sockets, command switches, noise suppression filters, electromagnetic switches, solar cell substrates, LCD panels, LED mounting substrates, flexible printed circuit boards, and flexible flat cables.

[0064] As automotive components, examples include, but are not limited to, thermostat housings, radiator tanks, radiator hoses, water outlets, water inlets, rear joints, and water pump housings; intercooler tanks, resonators, throttle bodies, intake manifolds, and tailpipes; fuel system components such as fuel delivery pipes, fuel tanks, quick connectors, canisters, pump modules, fuel lines, oil filters, lock nuts, and sealing materials; structural components such as mounting brackets, torque rods, and cylinder head covers; and bearing supports, gear tensioning devices, headlight actuator gears, and slide door rollers. Drive system components such as rollers and clutch peripheral components; brake system components such as air brake pipes; vehicle electrical components such as wiring harnesses, engine components, sensors, ABS ignition coils, combination switches, and vehicle switches in the engine compartment; interior and exterior components such as sliding door dampers, rearview mirror brackets, rearview mirror holders, rearview mirror brackets, roof longitudinal beams, engine mounting brackets, air intake pipes for air purifiers, door limiters, plastic chains, vehicle emblems, terminal blocks, circuit breaker covers, cup holders, airbags, mudguards, spoilers, radiator brackets, radiator grilles, heat dissipation vents, air ducts, hood bulges, rear doors, and fuel dispenser modules.

[0065] As industrial components, examples include gas pipes, oilfield development pipes, hoses, anti-termite cables (communication cables, path cables, etc.), coatings for powder coatings (inner coating of water pipes), subsea oilfield pipes, pressure hoses, hydraulic pipes, paint pipes, fuel pumps, separators, booster channels, butterfly valves, roller bearings for transport aircraft, sleeper spring bearings for railways, outboard motor engine covers, generator engine covers, irrigation valves, large switches, and single yarn (extruded yarn) for fishing nets, etc.

[0066] Examples of fibers include airbag base fabric, heat-resistant filters, reinforcing fibers, brush bristles, fishing lines, tire cords, artificial turf, carpets, and fibers for seating sheets. Examples of films and sheets include heat-resistant adhesive tapes such as heat-resistant shielding tapes and industrial tapes; magnetic tapes such as cassette tapes, data storage tapes for digital data storage devices, and videotapes; food packaging materials such as packaging bags for sterilized canned foods, individual packaging for snacks, and packaging for processed meat products; and packaging materials for electronic components such as packaging for semiconductor packaging.

[0067] In addition, polyamide compositions containing the polyamides of the present invention and the above-mentioned components are also suitable for use in plastic magnets, shoe soles, tennis rackets, skis, connecting magnets, eyeglass frames, cable ties, tag pins, crescent sash locks for window frames, fans for power tool engines, insulating blocks for engine mounts, engine covers for lawnmowers, fuel canisters for lawnmowers, miniature slide switches, DIP switches, switch housings, lamp holders, connector housings, IC slots, ignition coil covers, relay boxes, capacitor housings, small engine housings, gears, cams, balance wheels, partitions, insulators, retainers, casters, wire clips, automobile wheels, terminal blocks, insulating parts of starters, fuse boxes, air purifier housings, air conditioning fans, terminal block housings, wheel covers, bearing guards, water pipe turbines, clutch release bearing hubs, heat-resistant containers, microwave oven components, rice cooker components, printer ribbon guides, etc.

[0068] As long as the effects of the present invention are achieved, this invention includes various combinations of the above-mentioned technical solutions obtained within the technical scope of the present invention. Example

[0069] The present invention will be specifically described below through examples, but the present invention is not limited to these examples at all. The evaluation methods for various physical properties in the following examples are shown below.

[0070] <Amide conversion rate of polyamide precursors>

[0071] Dissolve 1 g of the polyamide precursor in 35 cc of phenol at 110 °C. After cooling to 20-30 °C, add 3 ml of methanol and a few drops of thymol blue, and titrate with 0.1 equivalent of hydrochloric acid to determine the amino concentration of the polyamide precursor. Regarding the amino concentration before the reaction, taking Example 1 as an example, 45.969 mol × 2 ÷ (7276.4 g + 7484.1 g + 224.55 g + 14.99 g) = 6.13 × 10⁻⁶. -3 The molar conversion rate is calculated as follows. The amidation conversion rate of the polyamide precursor is then expressed as 1 - (amino concentration of the polyamide precursor) ÷ 6.13 × 10⁻⁶. -3 The form is obtained by finding the answer.

[0072] <Monomer Composition of Polyamide>

[0073] 20-30 mg of polyamide was dissolved in 1 ml of deuterated 1,1,1,3,3,3-hexafluoro-2-propanol, and the reaction was performed using a JNM-ECX400 nuclear magnetic resonance spectrometer manufactured by NJE Ltd. at room temperature and an integration count of 256. 1 Based on H-NMR determination, the monomer composition of the polyamide was calculated according to Tables 1-3.1 The classification of polyamides by H-NMR is shown in Table 1. The calculation method for the molar ratio of polyamide constituent units is shown in Table 2. The calculation method for the monomer composition of polyamides is shown in Table 3.

[0074] [Table 1]

[0075]

[0076] [Table 2]

[0077]

[0078] (The meanings of symbols A to G in the table are shown in Table 1).

[0079] [Table 3]

[0080]

[0081] (The meanings of symbols H~K in the table are shown in Table 2).

[0082] <Hydroxy and ester groups of polyamides>

[0083] 20-30 mg of polyamide was dissolved in 1 ml of deuterated 1,1,1,3,3,3-hexafluoro-2-propanol, and the reaction was performed using a JNM-ECX400 nuclear magnetic resonance spectrometer manufactured by NJE Ltd. at room temperature and an integration count of 256. 1 The hydroxyl and ester groups of the polyamide were determined by ¹H-NMR analysis according to Tables 1, 2, and 4. The calculation methods for the hydroxyl and ester groups of the polyamide are shown in Table 4.

[0084] [Table 4]

[0085]

[0086] (The meanings of symbols I, J, L and M in the table are shown in Table 2).

[0087] <Melting point of polyamide>

[0088] Using a differential scanning calorimeter (DSC822) manufactured by Meta-Tred, 10 mg of polyamide was heated from 30°C to 350°C at a rate of 10°C / min under a nitrogen atmosphere, held at 350°C for 3 minutes, cooled to 50°C at a rate of 10°C / min, and held for 1 minute. Then, the temperature was increased from 50°C to 360°C at a rate of 10°C / min, and the peak temperature of the melting peak observed at this point was taken as the melting point. If multiple melting peaks were present, the peak temperature of the highest melting peak was taken as the melting point.

[0089] <Water absorption rate of polyamide>

[0090] Polyamide was molded into JIS flat plates (three sides of 80mm, 80mm, and 3mm). The weight change of the molded product before and after immersion in water at 80°C was taken as the water absorption rate of the polyamide.

[0091] <Weight-average molecular weight of polyamide>

[0092] A solution containing 10 mM sodium trifluoroacetate (HFIP) dissolved in 1,1,1,3,3,3,-hexafluoroisopropanol was used as the test solution preparation and eluent. 5 mg of polyamide was dissolved in 5 ml of the aforementioned solution and passed through a 2 μm membrane filter to prepare the test solution. 90 μL of the test solution was injected into an eluent at a rate of 1 ml / min and passed through a column (HFIP-806M, manufactured by Showa Denko Corporation) maintained at 40°C, followed by a dissolution profile (RID-10A, manufactured by Showa Denko Corporation). The weight-average molecular weight of the polyamide was calculated by comparing it with a composition profile prepared separately using a PMMA standard sample (STANDARD M-75, manufactured by Showa Denko Corporation, number-average molecular weight range: 1,800~950,000).

[0093] Impact resistance of polyamides

[0094] Polyamide was injection molded into ISO multi-object test piece A, and the notched Charpy impact value at 23°C was calculated according to ISO 179 / 1eA, which was used as an indicator of the impact resistance of polyamide.

[0095] <Example 1>

[0096] A nylon salt aqueous solution with a water content of 25% by mass was prepared by stirring a mixture of 7276.4 g (45.969 mol) of a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine in a molar ratio of 85:15, 7484.1 g (45.049 mol) of terephthalic acid, 224.55 g (1.839 mol) of benzoic acid, 14.99 g of sodium hypophosphite monohydrate, and 5000.0 g of water at 150 °C. A nylon salt aqueous solution with a liquid temperature of 150°C was supplied to reactor 1 at a rate of 1 L / hour via overflow to maintain a constant liquid content (the liquid content at 23°C overflow is 0.5 L) (the residence time is defined as 0.5 L ÷ 1 L / hour = 0.5 hours). The liquid temperature was adjusted to reach 250°C (the saturated vapor pressure of water at this temperature is 4.0 MPa) and the pressure reached 3.3 MPa (0.83 times the saturated vapor pressure of water). At this point, in order to maintain the pressure at 3.3 MPa, the vapor in the gas phase was stably removed from the system and condensed using a condenser. The condensate, which is mainly composed of water, was metered at 0.209 L / hour. The liquid overflowing from reactor 1 was introduced into reactor 2, which was adjusted to a liquid temperature of 250°C, a pressure of 3.3 MPa, and a residence time of 2.53 hours (the internal liquid content of water at 23°C is 2 L ÷ (1 - 0.209) L / hour = 2.53 hours). The contents of reactor 2 were indirectly heated from the outside with 120°C steam from the bottom and continuously supplied to a tank with an atmospheric opening at the top. In this tank, dehydration, cooling, and granulation were performed to obtain granular polyamide precursors with 50% by mass passing through a 0.5 mm sieve, 3% by mass moisture content, and an amidation conversion rate of 88%. These precursors were then subjected to solid-state polymerization for 10 hours in a batch reactor with a jacket temperature of 230°C and 1 torr to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0097] <Example 2>

[0098] The polyamide was obtained using the method described in Example 1, except that 7594.5 g (44.072 mol) of 1,10-decanediamine, 7175.3 g (43.191 mol) of terephthalic acid, and 215.28 g (1.763 mol) of benzoic acid were used. It should be noted that the amidation conversion rate of the polyamide precursor was 87%. The composition and properties of the obtained polyamide are shown in Table 5.

[0099] <Example 3>

[0100] The polyamide was obtained using the method described in Example 1, except that 6155.7 g (55.880 mol) of 1,6-hexanediamine, 5054.8 g (30.427 mol) of terephthalic acid, 3638.1 g (24.894 mol) of adipic acid, and 136.48 g (1.118 mol) of benzoic acid. It should be noted that the amidation conversion rate of the polyamide precursor was 87%. The composition and properties of the obtained polyamide are shown in Table 5.

[0101] <Example 4>

[0102] The polyamide was obtained using the method described in Example 1, except that 5957.9 g (54.084 mol) of 1,6-hexanediamine, 6226.6 g (37.480 mol) of terephthalic acid, 2668.5 g (16.063 mol) of isophthalic acid, and 132.09 g (1.082 mol) of benzoic acid were used. It should be noted that the amidation conversion rate of the polyamide precursor was 87%. The composition and properties of the obtained polyamide are shown in Table 5.

[0103] <Example 5>

[0104] The polyamide was obtained using the method described in Example 1, except that 3276.8 g (29.746 mol) of 1,6-hexanediamine, 2681.0 g (24.338 mol) of 2-methyl-1,5-pentanediamine, 8895.1 g (53.543 mol) of terephthalic acid, and 132.09 g (1.082 mol) of benzoic acid were used. It should be noted that the amidation conversion rate of the polyamide precursor was 87%. The composition and properties of the obtained polyamide are shown in Table 5.

[0105] <Comparative Example 1>

[0106] Except for setting the liquid temperature in reactor 1 to 270°C (at which temperature the saturated vapor pressure of water is 5.5 MPa) and the pressure to 4.5 MPa (0.82 times the saturated vapor pressure of water), the polyamide was polymerized using the method described in Example 1. The composition and properties of the resulting polyamide are shown in Table 5.

[0107] <Comparative Example 2>

[0108] Except that the liquid content in reactor 1 at 23°C during water overflow was set to 3.0L, the polyamide was polymerized using the method described in Example 1. The composition and properties of the resulting polyamide are shown in Table 5.

[0109] <Comparative Example 3>

[0110] 7276.4 g (45.969 mol) of a mixture of 1,9-nonanediamine and 2-methyl-1,8-octanediamine in a molar ratio of 85:15, 7484.1 g (45.049 mol) of terephthalic acid, 224.55 g (1.839 mol) of benzoic acid, 14.99 g of sodium hypophosphite monohydrate, and 15000.0 g of thermal conductivity A (a mixture of diphenyl ether and biphenyl in a mass ratio of 7:3) were added to a 50 L autoclave and purged with nitrogen. The internal temperature was raised to 230 °C over 2 hours, and the reaction was allowed to proceed directly for 3 hours. The reaction was carried out with constant stirring, and the pressure was appropriately released to ensure that it did not exceed 0.5 MPa. After cooling the contents to near room temperature, the contents were removed from the autoclave. Thermal conductivity A was removed using a 4G glass filter, and the mixture was dried at 200 °C under reduced pressure for 12 hours to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0111] <Comparative Example 4>

[0112] The nylon salt aqueous solution of Example 2 was reacted under the conditions of Comparative Example 1 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0113] <Comparative Example 5>

[0114] The nylon salt aqueous solution of Example 2 was reacted under the conditions of Comparative Example 3 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0115] <Comparative Example 6>

[0116] The nylon salt aqueous solution of Example 3 was reacted under the conditions of Comparative Example 1 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0117] <Comparative Example 7>

[0118] The nylon salt aqueous solution of Example 3 was reacted under the conditions of Comparative Example 3 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0119] <Comparative Example 8>

[0120] The nylon salt aqueous solution of Example 4 was reacted under the conditions of Comparative Example 1 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0121] <Comparative Example 9>

[0122] The nylon salt aqueous solution of Example 4 was reacted under the conditions of Comparative Example 3 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0123] <Comparative Example 10>

[0124] The nylon salt aqueous solution of Example 5 was reacted under the conditions of Comparative Example 1 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0125] <Comparative Example 11>

[0126] The nylon salt aqueous solution of Example 5 was reacted under the conditions of Comparative Example 3 to obtain polyamide. The composition and properties of the polyamide are shown in Table 5.

[0127] <Comparative Example 12>

[0128] The polyamide was obtained using the method described in Example 1, except that 5920.6 g (53.746 mol) of 1,6-hexanediamine, 8750.21 g (52.671 mol) of adipic acid, and 314.18 g (2.150 mol) of benzoic acid. It should be noted that the amidation conversion rate of the polyamide precursor was 92%. The composition and properties of the obtained polyamide are shown in Table 5.

[0129]

[0130] In Comparative Examples 1, 4, 6, 8, and 10, the temperature of reactor 1 was increased to 270°C, but the total amount of hydroxyl and ester groups in the polyamide exceeded the range specified in this invention, resulting in poorer impact resistance compared to the examples. In Comparative Example 2, the average residence time of reactor 1 was extended to 3 hours, but the total amount of hydroxyl and ester groups in the polyamide exceeded the range specified in this invention, resulting in poorer impact resistance compared to the examples. In the batch polymerization of Comparative Examples 3, 5, 7, 9, and 11, the total amount of hydroxyl and ester groups in the polyamide was not included in the range specified in this invention, resulting in poorer impact resistance compared to the examples. In Comparative Example 12, since it did not contain aromatic dicarboxylic acid units, it had a lower melting point and higher water absorption rate compared to the examples.

[0131] Industrial utilization

[0132] The polyamide resin of this invention exhibits excellent heat resistance, water resistance, and impact resistance, and can be effectively used to manufacture various molded articles of any shape and purpose, including electrical and electronic components, automotive components, industrial components, fibers, films, sheets, household goods, and others. Furthermore, the manufacturing method of the polyamide is useful for producing polyamides with excellent heat resistance, water resistance, and impact resistance.

Claims

1. Polyamide, which is a polyamide having structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines. The aliphatic diamine is selected from at least one of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine, but does not contain 1,4-butanediamine, 1,6-hexanediamine, and 2-methyl-1,5-pentanediamine. The aromatic dicarboxylic acid is terephthalic acid. The capping agent is benzoic acid. The content of structural units derived from aromatic dicarboxylic acids is 25-52 mol%, and the content of structural units derived from aliphatic diamines is 30-53 mol%. The total content of structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines does not exceed 100 mol%. Charpy impact value is 5.0 kJ / m 2 The Charpy impact value mentioned above is the notched Charpy impact value at 23°C obtained by injection molding polyamide into an ISO multi-mesh test piece A, according to ISO 179 / 1eA. Relative to 100 mol% of the structural units derived from dicarboxylic acids, the total hydroxyl and ester groups are 0.40–0.70 mol%. The polyamide has a water absorption rate of less than 2.0%. It contains 1.8 to 4 moles of structural units derived from the capping agent.

2. The polyamide according to claim 1, wherein, The content of structural units derived from aromatic dicarboxylic acids is 30-51 mol%, and the content of structural units derived from aliphatic diamines is 35-52 mol%. The total content of structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines does not exceed 100 mol.

3. Polyamide, which is a polyamide having structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines. The aliphatic diamine is selected from at least one of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine, but does not contain 1,4-butanediamine, 1,6-hexanediamine, and 2-methyl-1,5-pentanediamine. The aromatic dicarboxylic acid is terephthalic acid. The content of structural units derived from aromatic dicarboxylic acids is 25-51 mol%, and the content of structural units derived from aliphatic diamines is 30-52 mol%. The total content of structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines does not exceed 100 mol%. Charpy impact value is 5.0 kJ / m 2 The Charpy impact value mentioned above is the notched Charpy impact value at 23°C obtained by injection molding polyamide into an ISO multi-mesh test piece A, according to ISO 179 / 1eA. Relative to 100 mol% of the structural units derived from dicarboxylic acids, the total hydroxyl and ester groups are 0.40–0.70 mol%. Contains 1.8–4 mol% structural units derived from end-capping agents. The capping agent is benzoic acid.

4. The polyamide according to claim 3, wherein, The content of structural units derived from aromatic dicarboxylic acids is 30-51 mol%, and the content of structural units derived from aliphatic diamines is 35-52 mol%. The total content of structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines does not exceed 100 mol.

5. The polyamide according to claim 3 or 4, wherein the water absorption rate is less than 2.0%.

6. Polyamides, which are polyamides having structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines. The aliphatic diamine is selected from at least one of 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine, but does not contain 1,4-butanediamine, 1,6-hexanediamine, and 2-methyl-1,5-pentanediamine. The aromatic dicarboxylic acid is terephthalic acid. The content of structural units derived from aromatic dicarboxylic acids is 25-52 mol%, and the content of structural units derived from aliphatic diamines is 30-53 mol%. The total content of structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines does not exceed 100 mol%. Charpy impact value is 5.0 kJ / m 2 The Charpy impact value mentioned above is the notched Charpy impact value at 23°C obtained by injection molding polyamide into an ISO multi-mesh test piece A, according to ISO 179 / 1eA. Relative to 100 mol% of the structural units derived from dicarboxylic acids, the total hydroxyl and ester groups are 0.40–0.70 mol%. The polyamide has a water absorption rate of less than 2.0%. The capping agent is benzoic acid. It contains 1.8 to 2.5 mol of structural units derived from the capping agent.

7. The polyamide according to claim 6, wherein, The content of structural units derived from aromatic dicarboxylic acids is 30-51 mol%, and the content of structural units derived from aliphatic diamines is 35-52 mol%. The total content of structural units derived from aromatic dicarboxylic acids and structural units derived from aliphatic diamines does not exceed 100 mol.

8. A method for manufacturing the polyamide according to any one of claims 1 to 7, comprising the following steps: Step (1) involves supplying an aqueous solution of nylon salt with a concentration of 50-90% by mass and a liquid temperature of 100-180°C to the reactor; and The polymerization step (2) is carried out under the following conditions: the liquid temperature in the reactor is 230~260℃, the pressure in the reactor is 0.70~0.90 times the saturated vapor pressure of water at that liquid temperature, and the average residence time in the reactor is less than 1 hour.

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