JP2015206039A - Polyamide resin and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxalic acid-based polyamide resin which can achieve high polymerization degree in a short time and excels in melt retention stability, low water absorption and mechanical characteristics.SOLUTION: There is provided a polyamide resin obtained by polycondensing at least a dicarboxylic acid component and a diamine component, wherein the dicarboxylic acid component contains diphenyl oxalate in which the ratio to the total amount of the dicarboxylic acid component is 20 to 100 mol%, the diamine component contains an aliphatic diamine having 4 to 12 carbon atoms in which the ratio to the total amount of the diamine component is 20 to 100 mol% and a 96% sulfuric acid solution at a concentration of 0.01 g/mL has a relative viscosity at 25°C of 2.35 or more and 6.00 or less.

Description

  The present invention relates to a polyamide resin capable of increasing the degree of polymerization in a short time, having excellent melt residence stability, low water absorption, and excellent mechanical properties, and a method for producing the same.

  Nylon 6 and nylon 66, which are representative of crystalline polyamides, are widely used as clothing, industrial fibers, or general engineering plastics because of their excellent characteristics and ease of melt molding. However, on the other hand, there are problems such as changes in physical properties caused by water absorption, deterioration in acid, high-temperature alcohol, and hot water, and there is an increasing demand for polyamide resins with excellent dimensional stability, chemical resistance, and heat resistance. ing. In the field of electrical and electronic parts, with the development of surface mounting (SMT) technology, there is an increasing demand for polyamide resins having high heat resistance including reflow heat resistance. Thus, there is a need to develop high quality polyamides that have good heat resistance, good dimensional stability, and good chemical resistance.

  On the other hand, a polyamide resin called a polyoxamide having an oxalic acid unit as a dicarboxylic acid unit is known. Compared to other polyamide resins having the same amide group concentration, it has a low water absorption, so that it can solve the problem of deterioration of physical properties due to water absorption and can be expected to be used in a region where it is difficult to use the current polyamide.

  For example, polyoxamide having 1,6-diaminohexane as a diamine unit shown in Non-Patent Document 1 has a high melting point (320 ° C. or higher), and causes significant decomposition during melt processing. Further, among the polyoxamide PA62 / 2-M52 resins described in Patent Document 1, a polyoxamide resin having a melting point of 280 ° C. or higher does not increase in relative viscosity (relative viscosity is less than 2.05) and is resin during melt processing. Viscosities are greatly reduced. Furthermore, in the polyoxamide PA52 resin described in Patent Document 2, the viscosity is increased by a specific solid phase polymerization method, but the melt retention stability is poor, and the viscosity of the polyoxamide resin is greatly reduced during melt processing. On the other hand, Patent Document 3 shows that the melt retention stability of oxalic acid-based polyamide is improved by copolymerization.

Journal of Polymer Science, 1973, Volume 11, P1-14

International Publication No. 2011-136263 JP 2011-236387 A Chinese Patent Publication No. 104211185

  In the prior art, it has been difficult to obtain an oxalic acid-based polyamide resin that can increase the degree of polymerization in a short time, and has excellent melt retention stability, low water absorption, and excellent mechanical properties. An object of the present invention is to obtain a polyamide resin satisfying the above characteristics.

  In the polyamide resin obtained by polycondensation of an oxalic acid diester and an aliphatic diamine having 4 to 12 carbon atoms, the present inventors mainly used diphenyl oxalate as the oxalic acid diester, and thereby highly polymerized in a short time. It has been found that a polyamide resin can be obtained, which can be melted and has excellent melt residence stability, low water absorption, and excellent mechanical properties.

That is, the polyamide resin of the present invention is as follows.
(I) At least a polyamide resin obtained by polycondensation of a dicarboxylic acid component and a diamine component, wherein the dicarboxylic acid component contains 20 to 100 mol% of diphenyl oxalate, based on the total amount of the dicarboxylic acid component, The relative viscosity A at 25 ° C. of a 96% sulfuric acid solution in which the diamine component contains an aliphatic diamine having 4 to 12 carbon atoms having a ratio of 20 to 100 mol% to the total amount of the diamine component and 0.01 g / ml is 2. A polyamide resin of 35 to 6.00,
(Ii) Melting point + 20 ° C. The ratio (B / A) of the relative viscosity B of the polyamide resin after being melted and retained for 30 minutes in an inert gas atmosphere (B / A) is 0.80 to 2.0. Polyamide resin,
(Iii) Using a differential scanning calorimeter, when the temperature is lowered to 30 ° C. at a temperature lowering rate of 20 ° C./min from the molten state in an inert gas atmosphere, and then heated at a temperature rising rate of 20 ° C./min. Any of the above polyamide resins having an endothermic peak temperature (Tm: melting point) of 270 to 320 ° C .;
(Iv) The polyamide resin according to any one of the above, wherein the ratio (E / F) of the supply molar amount (E) of the diamine component to the supply molar amount (F) of the dicarboxylic acid component is 0.90 to 1.10.
(V) the polyamide resin according to any one of the above, wherein the content of formamide end groups (—NH—CHO) is less than 0.12 mmol / g;
(Vi) The polyamide resin as described above, wherein the aliphatic diamine having 4 to 12 carbon atoms is 1,5-pentanediamine.
(Vii) any one of the above polyamide resins, wherein the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography test is 5.0 or less;
(Viii) Any one of the polyamide resins further comprising one or more selected from transition metal halides, alkali metal halides, or alkaline earth metal halides.
The present invention also includes a method for producing a polyamide resin.
(Ix) A method for producing a polyamide resin obtained by polycondensation of at least a dicarboxylic acid component and a diamine component, wherein diphenyl oxalate having a ratio to the total amount of the dicarboxylic acid component of 20 to 100 mol%, the total amount of the diamine component A method for producing a polyamide resin, in which an aliphatic diamine having 4 to 12 carbon atoms and a relative viscosity A of 2.35 or more and 6.00 or less is mixed;
(X) A method for producing the polyamide resin comprising a step of post-polymerizing a prepolymer having a relative viscosity of 1.02 to 1.80, followed by a temperature range of 200 ° C to 335 ° C for less than 3 hours,
(Xi) The method for producing the polyamide resin of (x), wherein the post-polymerization step time is less than 2 hours,
(Xii) At least one selected from transition metal halides, alkali metal halides, or alkaline earth metal halides is added during prepolymer synthesis or post-polymerization step (x) or (xi) A method for producing a polyamide resin of
(Xiii) The method for producing a polyamide resin according to any one of the above, wherein the ratio (E / F) of the supply molar amount (E) of the diamine component and the supply molar amount (F) of the dicarboxylic acid component is 0.90 to 1.10.
It is.

  According to the present invention, it is possible to obtain a polyamide resin capable of increasing the degree of polymerization in a short time and having excellent melt residence stability, low water absorption, and mechanical properties.

In the embodiment of the present invention, diamine is defined as a diamine component, dicarboxylic acid, dicarboxylic acid dialkyl ester, and dicarboxylic acid diphenyl ester as a dicarboxylic acid component.

  The present invention is at least a polyamide resin obtained by polycondensation of a dicarboxylic acid component and a diamine component, and the dicarboxylic acid component contains diphenyl oxalate having a ratio of 20 to 100 mol% with respect to the total amount of the dicarboxylic acid component. The diamine component contains an aliphatic diamine having 4 to 12 carbon atoms having a ratio of 20 to 100 mol% with respect to the total amount of the diamine component, and a relative viscosity A at 25 ° C. of 96% sulfuric acid solution of 0.01 g / ml is 2 It relates to a polyamide resin of .35 or more and 6.00 or less.

  The diamine component used by this invention contains a C4-C12 aliphatic diamine whose ratio with respect to the diamine component total amount is 20-100 mol%. In order to improve crystallinity, 50 mol% or more is preferable, 80 mol% or more is more preferable, 90 mol% or more is more preferable, and 96 mol% or more is the most preferable. Moreover, it is preferable to use a single aliphatic diamine.

  Examples of the aliphatic diamine having 4 to 12 carbon atoms used in the present invention include 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8- Octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2-methyl-1,5-pentanediamine, 2-methyl-1,8-octane One or more selected from diamine, cyclohexanediamine and the like can be mentioned. In order to improve the heat resistance and crystallinity of the polyamide resin, it is preferable to use a linear diamine, and at least one selected from 1,4-butanediamine, 1,5-pentanediamine, and 1,6-hexanediamine. More preferably, seeds are used. In order to achieve both heat resistance and melt processability, it is most preferable to use 1,5-pentanediamine.

  Moreover, as diamine other than C4-C12 aliphatic diamine which can be mix | blended with respect to diamine component total amount, it is 1,13- tridecane diamine, 1,14- tetradecane diamine, Examples include 1,15-pentadecanediamine, 1,16-hexadecanediamine, 1,17-heptadecanediamine, 1,18-octadecanediamine, and xylylenediamine. In order to improve the heat resistance and crystallinity of the polyamide resin, 0 to 50 mol% is preferable, 0 to 20 mol% is more preferable, 0 to 10 mol% is further preferable, and 0 mol% is most preferable.

  The dicarboxylic acid component used in the present invention contains diphenyl oxalate having a ratio of 20 to 100 mol% with respect to the total amount of the dicarboxylic acid component. 50-100 mol% is preferable, 60-100 mol% is more preferable, 80-100 mol% is more preferable, 100 mol% is the most preferable. Since diphenyl oxalate, which is an essential component of the present invention, has a higher reactivity with diamine than dialkyl oxalate, the degree of polymerization can be increased in a shorter time. Therefore, the heat history at the time of superposition | polymerization becomes small, and the melt residence stability of a polyamide resin and a mechanical characteristic can be improved.

  Examples of dicarboxylic acids other than diphenyl oxalate used in the present invention include dimethyl oxalate, diethyl oxalate, di-n-propyl oxalate, isopropyl oxalate, di-n-butyl oxalate, isobutyl oxalate, or oxalate. Oxalic acid derivatives such as di-t-butyl acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,11-undecyl diacid, 1,12-dodecyl diacid Acid, 1,13-tridecyl diacid, 1,14-tetradecyl diacid, 1,15-pentadecyl diacid, 1,16-cetyl diacid, 1,18-octadecyl diacid, 1,19-nonadecyl diacid, Or aliphatic dicarboxylic acid derivatives such as dialkyl esters thereof, and alicyclic dicarboxylic acids such as 1,4- / 1,3-cyclohexanedicarboxylic acid. One or more selected from aromatic dicarboxylic acids and derivatives thereof such as rubonic acid, terephthalic acid, isophthalic acid, dimethyl terephthalate, diethyl terephthalate, dimethyl isophthalate, diethyl isophthalate, oxalic acid chloride, oxalic acid chloride ester, etc. Can be mentioned.

  In the present invention, at least one selected from lactam and aminocarboxylic acid can be further copolymerized. Examples of the lactam include ε-caprolactam and ω-laurolactam. Examples of the aminocarboxylic acid include 6-aminocaproic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. The addition amount of lactam and aminocarboxylic acid is 0 to 20 mol%, more preferably 0 to 10 mol%, based on 100 mol% of the polyamide resin raw material.

  In order to improve the heat resistance and melt processability of the polyamide resin, the amide group content of the polyamide resin of the present invention (mole number of amide groups with respect to 1 g of polyamide) is 7.8 mmol / g to 14.5 mmol / g. It is preferable that it is 9.0 mmol / g-14.0 mmol / g, and it is further more preferable that it is 11.0-13.0 mmol / g. When the amide group content is less than 7.8 mmol / g, the melting point of the polyamide resin is low, and the heat resistance may be lowered. If the amide group content exceeds 14.5 mmol / g, the melting point of the polyamide resin may be too high to be melt processed.

  In the present invention, the relative viscosity (A) ηr of a 96% concentrated sulfuric acid solution having a polyamide resin concentration of 0.01 g / ml measured at 25 ° C. is in the range of 2.35 to 6.00. More preferably, it is 2.50 to 4.50. When ηr is less than 2.35, the molded product becomes brittle and physical properties may be lowered. On the other hand, when ηr is higher than 6.00, the melt viscosity is high and the moldability may be lowered.

  The melt residence stability of the polyamide resin obtained by the present invention is as follows. The ratio (B / A) between the relative viscosity B of the polyamide resin and the relative viscosity A when melted and retained in an inert gas atmosphere at a temperature of the melting point of the polyamide resin + 20 ° C. for 30 minutes is 0.80 to 2. 0 is preferred. More preferably, it is 0.85-1.7, More preferably, it is 0.90 to 1.6. By setting B / A to 0.80 to 2.0, the change in the melt viscosity of the polyamide resin in the melt processing step is small and stable processing can be performed.

  The thermal characteristics of the polyamide resin obtained by the present invention are as follows. The temperature of the polyamide resin is lowered from the molten state to 30 ° C. at a temperature lowering rate of 20 ° C./min in an inert gas atmosphere using a differential scanning calorimeter, It is preferable that the temperature (Tm: melting point) of the endothermic peak appearing in the temperature rising process at a temperature rising rate of 20 ° C./min is 270 to 320 ° C. The endothermic peak temperature (Tm: melting point) is more preferably 275 ° C. to 315 ° C., further preferably 280 ° C. to 310 ° C., and most preferably 301 to 310 ° C. By setting the endothermic peak temperature (Tm: melting point) to 270 ° C. to 320 ° C., a polyamide resin having excellent heat resistance and melt processability can be obtained. When a plurality of endothermic peaks appear, the endothermic peak temperature having the highest temperature is defined as the melting point.

  The ratio (E / F) of the supply molar amount E of the diamine component to the supply molar amount F of the dicarboxylic acid component is preferably 0.90 to 1.01. By setting the molar ratio to 0.90 to 1.10, the equimolarity of the diamine component and the dicarboxylic acid component is maintained appropriately, and the degree of polymerization can be easily increased. The molar ratio (E / F) is more preferably 0.92 to 1.08, and further preferably 0.93 to 1.06. By setting the molar ratio (E / F) to 0.90 to 0.99, the degree of polymerization of the polyamide resin of the present invention can be further increased in a short time. Moreover, melting | fusing point of the polyamide resin of this invention can be made high by making molar ratio (E / F) 1.01-1.10.

  In general, a polyamide resin having a oxalic acid component such as oxalic acid diester or diphenyl oxalate as a structural unit generates formamide end groups by decomposition of the oxalic acid component. Since the formamide end group is non-reactive, it becomes more difficult to increase the degree of polymerization as the production amount increases. In the present invention, the formamide terminal of the polyamide resin is preferably less than 0.12 mmol / g. More preferably, it is less than 0.10 mmol / g, More preferably, it is less than 0.08 mmol / g. By setting the formamide content in the polyamide resin to less than 0.12 mmol / g, the relative viscosity of the polyamide resin can be easily improved.

The formamide terminal in the polyamide resin can be quantified by the following method. Here, an example of nylon 52 produced using diphenyl oxalate and 1,5-pentanediamine as raw materials is shown, and a method for quantifying formamide end groups by ¹ H-NMR measurement is shown. When deuterated concentrated sulfuric acid (sigma: concentration 96 to 98 wt%, containing heavy water D ₂ O) is used as a solvent, hydrogen of undeuterated sulfuric acid partially contained in deuterated concentrated sulfuric acid (10.3 ppm) ), And absorption by hydrogen present in the main chain methylene group (—CH ₂ —NH—CO—) adjacent to the formamide end group (—NH—CHO) and the amide group is detected. The formamide end group content can be determined by the following calculation formula.

(Note that [—NH—CHO] is the area value of absorption (7.8 ppm) by hydrogen constituting the formyl group in the formamide end group,
[—CH 2 —NH—CO—] is an area value of absorption (3.1 ppm) by hydrogen constituting a methylene group adjacent to the amide group in the main chain.

[—NH—CHO]: [—CH ₂ —NH—CO —] / 4 = 1: [number of repeating units]
[Number of repeating units per mol of formamide end group] = [— CH ₂ —NH—CO —] / (4 × [—NH—CHO])
Formamide terminal group amount (mol / g) = 1 / (156.2 × [number of repeating units]), where 156.2 is the molecular weight of the repeating unit, and 156.2 × [number of repeating units] is the formamide terminal Corresponds to the molecular weight of the polyamide resin per mole.

  The molecular weight distribution of the polyamide resin obtained by the present invention can be measured by a gel permeation chromatography test. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 5.0 or less. More preferably, it is less than 4.5, More preferably, it is less than 4.0. When Mw / Mn is larger than 5.0, the ratio of the low molecular weight component in the polyamide resin is relatively increased, so that the bending strength tends to decrease.

  The polyamide resin obtained by the present invention may further contain one or more selected from transition metal halides, alkali metal halides, or alkaline earth metals. These transition metal halides, alkali metal halides, and alkaline earth metals are not incorporated into the skeleton of the polyamide resin, but are contained in a dispersed state in the polyamide resin. Although it does not specifically limit as said transition metal halide, One or more types, such as a copper halide, a zinc halide, or a manganese halide, are mentioned. Specifically, copper iodide, cuprous iodide, copper bromide, cuprous bromide, cupric chloride, cuprous chloride, manganese dichloride, manganese dibromide, manganese diiodide, iodine One or more of zinc chloride, zinc bromide, and zinc chloride can be mentioned. Here, preferably, it is at least one of cuprous iodide, cuprous bromide, cuprous chloride, copper chloride, manganese diiodide, or zinc iodide. More preferably, it is at least one of cuprous iodide, manganese diiodide, or zinc iodide.

  The alkali metal halide described above is not particularly limited, but may include one or more of lithium halide, sodium halide, potassium halide, and the like. Specific examples include one or more of potassium iodide, potassium bromide, potassium chloride, sodium iodide, sodium chloride, sodium bromide, lithium chloride, lithium bromide, or lithium iodide. Here, it is preferably at least one of potassium iodide, sodium iodide, potassium bromide, sodium bromide, lithium chloride, or lithium iodide. More preferably, it is at least one of potassium iodide, sodium iodide, sodium bromide, or potassium bromide.

  There is no restriction | limiting in particular as said alkaline-earth metal halide, One or more types, such as a calcium halide, a magnesium halide, or a barium halide, can be mentioned. Specific examples include one or more of calcium iodide, calcium bromide, calcium chloride, barium iodide, barium bromide, barium chloride, magnesium iodide, magnesium bromide, or magnesium chloride. Among them, one or more of calcium iodide, barium iodide, magnesium chloride, or magnesium iodide is more preferable. More preferably, it is at least one of calcium iodide, barium iodide, or magnesium iodide.

  The transition metal, alkali metal, and / or alkaline earth metal content contained in the transition metal halide, alkali metal halide, or alkaline earth metal halide in the polyamide resin is 100 to 100% by weight of the polyamide resin. It is preferable that it is 4000 ppm, More preferably, it is 100-3000 ppm, More preferably, it is 100-2500 ppm. By setting the alkali metal and / or alkaline earth metal content within the above range, the melt residence stability can be further improved, and the precipitation of the metal or the corrosion of the polymerization apparatus can be suppressed. The polyamide resin undergoes thermal decomposition as described in Polymer Degradation and Stability 49 (1995), pages 127 to 133 during a high temperature processing step or when used in a high temperature environment. The methylene group adjacent to the nitrogen atom of the amide group tends to form free radicals easily. The free radical is stabilized by a resonance structure formed by a π bond between a lone pair on nitrogen and a carbonyl group. The polyamide resin of the present invention includes an oxamide unit as a structural unit, and the oxamide unit is adjacent to two amide groups, and can form a more stable resonance structure than a general single amide group. . Therefore, the polyamide resin of the present invention is more likely to generate radicals on the methylene group adjacent to the nitrogen of the amide group than the normal polyamide resin such as nylon 66, and is more likely to be thermally oxidized and deteriorated. Therefore, the present invention can further effectively suppress the thermal oxidative degradation of the oxalic acid unit polyamide resin having a melting point of 270 ° C. or higher by adding the metal halide.

  As a manufacturing method of the polyamide resin of the present invention, a dicarboxylic acid raw material in which 20 to 100 mol% with respect to the total amount of the dicarboxylic acid component is diphenyl oxalate, and an aliphatic with 4 to 12 carbon atoms in the amount of 20 to 100 mol% with respect to the total amount of the diamine component Examples thereof include a method in which a diamine raw material that is diamine is mixed and polymerized until the relative viscosity A becomes 2.35 or more and 6.00 or less. Specifically, after synthesizing a prepolymer having a relative viscosity of 1.02 to 1.80, post-polymerization until a relative viscosity of 2.35 to 6.00 is achieved within a temperature range of 200 ° C. to 335 ° C. for less than 3 hours. The manufacturing method of the polyamide resin including the process to perform can be mentioned. By setting the post-polymerization process time to less than 3 hours, the heat history during polymerization can be reduced, and the melt residence stability of the resulting polyamide resin can be improved. The post-polymerization process time is more preferably less than 2 hours.

  The ratio (E / F) of the supply molar amount (E) of the diamine component to the supply molar amount (F) of the dicarboxylic acid component is preferably 0.90 to 1.10, more preferably 0.92 to 1.08, more preferably 0.93 to 1.06.

  In order to further improve the melt residence stability, it is preferable to add one or more transition metal halides, alkali metal halides, or alkaline earth metal halides in the prepolymer synthesis or post-polymerization step.

  In the method for producing a polyamide resin of the present invention, the diamine component and the dicarboxylic acid component have the same contents as the diamine component and the dicarboxylic acid component.

  More specific production methods include the methods listed below.

Production method 1 (Prepolymer synthesis)
The monomer raw material of the polyamide resin is the above-described diamine component and dicarboxylic acid component (containing 20 to 100 mol% of diphenyl oxalate). First, an organic solvent is added to a reactor equipped with a general cooler, then a dicarboxylic acid component (completely dissolved in the solution) is added, and after purging with nitrogen, stirring is started, and then the diamine component is added. Add (in the case of solid materials, dissolve first to make a solution) and mix. Heating is then started and allowed to react for 0.15 to 2 hours at the reflux temperature of the solvent, then filtered, washed 3-5 times with methanol or ethanol, and the resulting prepolymer is dried or prepolymer The solvent is removed directly from the dispersion under reduced pressure. Although it does not specifically limit as an organic solvent, Toluene, xylene, chlorobenzene, phenol, trifluoroethanol, etc. are mentioned, Toluene is preferable.

Production method 2 (post-polymerization: higher degree of melt polymerization)
The prepolymer obtained in production method 1 is added to the reactor, and the atmosphere is purged with nitrogen. This reactor is put into a heater, and then heating is started, the temperature is raised to a temperature equal to or higher than the melting point of the prepolymer, and polymerization is performed under reduced pressure at a final pressure of 5000 to 20 Pa for 0.15 to 3 hours, or an inert gas stream Under normal pressure polymerization for 0.15 to 3 hours.

Production method 3 (post-polymerization: increasing the degree of solid-phase polymerization)
The prepolymer obtained in production method 1 is added to the reactor, and the atmosphere is purged with nitrogen. Thereafter, solid-state polymerization under reduced pressure at a temperature below the melting point, 0.15 to 3 hours, and a final pressure of 300 to 20 Pa, or solid-state polymerization at normal pressure for 0.15 to 3 hours in an inert gas atmosphere.

  The polyamide resin of the present invention may contain various fillers as necessary, and specific fillers are as follows.

  For example, as non-fibrous inorganic filler, graphite, barium sulfate, calcium carbonate, antimony oxide, titanium oxide, aluminum oxide, nickel, aluminum, iron, steel, talc, bentonite, montmorillonite, mica, titanium dioxide, silica, silicic acid Examples thereof include a filler such as salt. As the layered silicate, montmorillonite obtained by exchanging organic cations between layers with organic ammonium ions can also be used. In order to obtain a polyamide resin having an excellent surface appearance, the average particle size of the inorganic filler is preferably 0.001 to 10 μm. When the average particle size is less than 0.001 μm, the melt processability of the resulting polyamide resin composition is significantly reduced. On the other hand, when the average particle size is greater than 10 μm, the appearance of the molded product tends to deteriorate. is there.

  Moreover, an organic fibrous filler and an inorganic fibrous filler are mentioned. Examples of the organic fibrous filler include aromatic polyamide fibers such as wholly aromatic polyamide fibers, and cellulose fibers. Examples of the inorganic fibrous filler include glass fiber, carbon fiber, and boron fiber. Moreover, 1 or more types, such as whisker or needle-like crystals, such as metal fiber, potassium titanate, aluminum borate, gypsum, calcium carbonate, magnesium sulfate, sepiolite, zonolite, wollastonite, are mentioned. Furthermore, a long fiber having a length of 5 to 50 mm can be used, and a fiber having a length of 0.05 to 5 mm can be used.

  When producing the polyamide resin of the present invention, various additives such as a weathering agent, a release agent, a lubricant, a pigment, a dye, a plasticizer, an antistatic agent, a flame retardant, or one as necessary. Other polymers as described above can be added. Specifically, resorcinol-based, salicylic acid-based, benzotriazole-based, benzophenone-based, hindered amine-based weathering agents, or release agents such as aliphatic alcohols, aliphatic amides, aliphatic bisamides, bisureas, polyethylene waxes, Lubricants, pigments such as cadmium sulfide, phthalocyanine and carbon black, dyes such as nigrosine and aniline black, plasticizers such as hydroxybenzoic acid octyl ester and N-butylbenzenesulfonamide, alkylsulfate anionic antistatic agents, Antistatic agent such as quaternary ammonium salt type cationic antistatic agent, nonionic antistatic agent such as polyoxyethylene sorbitan monostearate alcohol or betaine amphoteric antistatic agent, melamine cyanurate, magnesium hydroxide or aluminum hydroxide Hydroxides such as nium, ammonium polyphosphate, brominated polyethylene, brominated polyphenylene sulfide, polybrominated polycarbonate, brominated epoxy or combinations of these bromide flame retardants and antimony trioxide, polyamide, polyethylene, polypropylene, polyester, Other polymers such as polycarbonate, polyphenylene ether, polyphenylene sulfide, liquid crystal polymer, ABS resin, SAN resin and polystyrene can be added.

  In order to improve the impact resistance of the polyamide resin of the present invention, a modified polyolefin such as a (co) polymer obtained by polymerizing an olefin compound and / or a conjugated diene compound is preferably used.

  Examples of the (co) polymer include an ethylene copolymer, a conjugated diene polymer, and a conjugated diene-aromatic vinyl hydrocarbon copolymer. Here, the ethylene copolymer refers to a copolymer and a multi-component copolymer of ethylene and another monomer, and the other monomer copolymerized with ethylene is an α- having 3 or more carbon atoms. It can be selected from olefins, non-conjugated dienes, vinyl acetate, vinyl alcohol, α, β-unsaturated carboxylic acids and derivatives thereof.

  The polyamide resin composition of the present invention can be molded into a desired shape by any molding method such as injection molding, extrusion molding, blow molding, vacuum molding, melt spinning and film formation. It can be used for resin molded products such as parts, machine parts, household goods, office supplies, building materials, sports equipment, fibers, films, and the like. Specifically, automotive engine cooling system parts, radiator tank parts such as radiator tank top and base, coolant reserve tank, water pipe, water pump housing, water pump impeller, water pump parts such as valves, etc. Components used in contact with cooling water, small switches, switch housings, lamp sockets, connectors, connector housings, connector shells, IC sockets, bobbins, bobbin covers, relays, relay boxes, capacitor cases, Internal parts of motor, small motor case, gear, cam, dancing pulley, spacer, insulator, fastener, buckle, clip, caster, helmet, terminal block, starter insulation, Poiler, canister, radiator tank, chamber tank, reservoir tank, fuse box, air cleaner case, air conditioner fan, terminal housing, wheel cover, intake / exhaust pipe, bearing retainer, cylinder head cover, intake manifold, clutch release, wire / cable coating It is useful for various applications such as materials and optical fiber cable cases.

  The following examples illustrate the invention, but the invention is not limited to these embodiments. Various characteristics in Examples and Comparative Examples were measured by the following methods.

(1) Using 96% sulfuric acid as a relative viscosity solvent, the relative viscosity of a polyamide resin sulfuric acid solution prepared at a concentration of 0.01 g / ml was measured at 25 ° C.

(2) Thermal characteristics Using a TA DSC-Q100 analyzer, about 5 mg of a sample was accurately weighed and measured under the following test conditions. In a nitrogen atmosphere, the obtained polyamide resin was heated to a temperature 30 ° C. higher than the endothermic peak temperature (T0) that appeared when the temperature was raised to 20 ° C./min, and held at that temperature for 2 minutes. The solution was cooled to 30 ° C. at a temperature decrease rate of ° C./min, and held at 30 ° C. for 2 minutes. Next, the temperature (Tm: melting point) of the endothermic peak observed when the temperature was raised to a temperature 30 ° C. higher than T0 at a rate of temperature increase of 20 ° C./min was obtained.

(3) Retention stability Under a nitrogen atmosphere, the sample obtained by melting and holding at a temperature 20 ° C. higher than the melting point for 30 minutes is (B), the relative viscosity before retention is (A), and the relative viscosity of sulfuric acid Viscosity retention (B / A) was determined.

(4) Molecular weight distribution Using gel permeation chromatography (GPC), 2.5 mg of polyamide resin was dissolved in 4 mL of hexafluoroisopropanol (0.005N-sodium trifluoroacetate added) and filtered through a 0.45 μm filter. The obtained solution was used for the measurement. The ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) obtained by the measurement was used as a measure of the molecular weight distribution of the polymer.
Apparatus: e-Alliance GPC system (e-Alliance 2695XE separation module) (manufactured by Waters)
Detector: 2414 differential refractometer (manufactured by Waters)
Column: Shodex HFIP-806M (2) + HFIP-LG
Solvent: hexafluoroisopropanol (added 0.005N sodium trifluoroacetate)
Flow rate: 0.5 mL / min Sample injection amount: 0.1 mL
Temperature: 30 ° C
Molecular weight calibration: polymethylmethacrylate.

(5) Quantification of formamide end group JNM's JNM-ECX400P (400 MHz) was used as a measuring device, deuterated sulfuric acid was used as a measuring solvent, and the number of integration was 256 times.

[-NH-CHO] area value of ... formamide end groups _[-CH 2 -NH-CO-] area value of the methylene group adjacent to the amide group in ... backbone [-NH-CHO]: [ _{-CH 2 -NH-CO -] /} 4 = 1: [ number of repeating units]
[Number of repeating units per mol of formamide end group] = [— CH ₂ —NH—CO —] / (4 × [—NH—CHO])
Formamide terminal group amount (mol / g) = 1 / (156.2 × [number of repeating units]), where 156.2 is the molecular weight of the repeating unit, and 156.2 × [number of repeating units] is the formamide terminal This is the molecular weight of the polyamide resin per mole.

(6) Bending performance test Using a test piece prepared under the following injection molding conditions, it was evaluated according to the method of ASTM D790, and the test result is an average value of five samples.
Injection molding machine: ST10S2V (manufactured by Nissei)
Injection temperature: 310 ° C. (Example 8, Comparative Examples 5 to 7)
270 ° C. (Comparative Example 8)
295 ° C. (Comparative Example 9)
Mold temperature: 130 ° C. (Example 8, Comparative Examples 5 to 7)
80 ° C. (Comparative Example 8)
80 ° C. (Comparative Example 9)
Test piece: length 64 mm x width 12.7 mm x thickness 3.0 mm
Bending performance test device: AG-IS-20KN (Shimadzu Corporation).

(7) Saturated water absorption at 23 ° C. The film hot-pressed at a temperature of the melting point of the polyamide resin + 20 ° C. was rapidly cooled in ice water to obtain a sample having a thickness of 0.1 to 0.5 mm (50 mm × 50 mm). The sample was immersed in water at 23 ° C. to a constant weight (W1), and then the sample was vacuum dried at 100 ° C. to a constant weight (W2). Water absorption (%) = 100 × (W1-W2) / W2 was calculated.
Abbreviations Description DN4: 1,4-butanediamine, DN5: 1,5-pentanediamine, DN6: 1,6-hexanediamine, DN10: 1,10-decanediamine, DPO: diphenyl oxalate, DBO: dibutyl oxalate, DEO: diethyl oxalate, AA: adipic acid DN4: purity 98%, purchased from Sigma-Aldrich.
DN5: purity 97%, purchased from Sigma-Aldrich.
DN6: purity 98%, purchased from Sigma-Aldrich.
DN10: Purity 98%, purchased from Wuxi Xingda Corporation.
DPO: Purity 98%, purchased from TCI.
DBO: Purity 99%, purchased from Sigma-Aldrich.
DEO: Purity 99%, purchased from Sigma-Aldrich.
AA: Analytical purity, purchased from Aladdin.
CuI: Analytical purity, purchased from Sigma-Aldrich.
KI: Analytical purity, purchased from Sigma-Aldrich.

Example 1
Initially, a three-necked flask (500 ml) was purged with nitrogen for 15 minutes to maintain a stream of nitrogen. Toluene (300 ml) and DPO (24.22 g, 0.100 mol) were added to the three-necked flask, and then stirring was started, and the temperature was raised to 70 ° C. DPO was completely dissolved in 70 ° C. toluene, and then DN5 (10.73 g, 0.105 mol) was added thereto. Next, the temperature was raised to 130 ° C., and the reaction was refluxed for 1 hour. After filtration and washing, it was dried in a vacuum oven at 100 ° C. for 12 hours. The relative viscosity of the obtained prepolymer was 1.49.

  2.00 g of the obtained prepolymer was supplied to a glass tube having a diameter of 19 mm and repeatedly purged with nitrogen five times. The pressure of the system was lowered to 300 Pa or less, and then placed in a metal bath at 280 ° C. After 5 hours, a polymerization reaction was performed. Table 1 shows the characteristics of the polymer.

Example 2
In the same manner as in Example 1, the prepolymer production method was performed by supplying 2.00 g of the obtained prepolymer to a glass tube having a diameter of 19 mm, and repeatedly performing nitrogen substitution five times. The pressure of this system was reduced to 300 Pa or less, Thereafter, it was placed in a metal bath at 325 ° C. and subjected to a polymerization reaction after 0.5 hours. Table 1 shows the characteristics of the polymer.

Example 3
The results are the same as in Example 2 except that CuI / KI is added to the prepolymer. The results are shown in Table 1.

Comparative Example 1
The results are the same as in Example 1, except that DBO is used as the dicarboxylic acid component, and the results are shown in Table 1.

Comparative Example 2
The results are shown in Table 1, except that DBO was used as the dicarboxylic acid component and the post-polymerization time was 5.0 hours.

Comparative Example 3
The results are shown in Table 1, except that DBO was used as the dicarboxylic acid component and the post-polymerization time was 3.0 hours.

Comparative Example 4
The results are shown in Table 1, except that DEO was used as the dicarboxylic acid component and the post-polymerization time was 3.0 hours.

Example 4
The results are shown in Table 2, except that the molar ratio of DN5 and DPO is 1.03.

Example 5
The results are the same as in Example 1 except that the molar ratio of DN5 and DPO is 1.00. The results are shown in Table 2.

Example 6
The results are shown in Table 2, except that the molar ratio of DN5 and DPO was 0.98, and the post-polymerization time was 1.0 hour.

Example 7
The results are shown in Table 2, except that the molar ratio of DN5 and DPO was 0.95, and the post-polymerization time was 1.0 hour.

Example 8
The results are the same as in Example 2 except that the amounts of DN5 (0.525 mol) and DPO (0.500 mol) are increased. The results are shown in Table 3.

Comparative Example 5
The results are the same as those in Comparative Example 3 except that the amounts of DN5 (0.525 mol) and DBO (0.500 mol) are increased. The results are shown in Table 3.

Comparative Example 6
The results are the same as those in Comparative Example 2 except that the amounts of DN5 (0.525 mol) and DBO (0.500 mol) are increased. The results are shown in Table 3.

Comparative Example 7
Example except that DBO was used as the dicarboxylic acid component, KI was added during post-polymerization, the amounts of DN5 (0.525 mol) and DBO (0.500 mol) were increased, and the post-polymerization time was 1.0 hour. 2 and the results are shown in Table 3.

Comparative Example 8 (Production of N66)
DN6 (3.559 g, 0.0306 mol), AA (4.440 g, 0.0304 mol) and deionized water (4.530 g) were added to a 19 mm diameter glass tube. Next, the glass tube was put in an autoclave and sealed, and was purged with nitrogen three times. Subsequently, the pressure in the autoclave was maintained at 0.02 MPa. Thereafter, the set temperature of the autoclave was set to 241 ° C., the temperature increase was started, and the pressure of the autoclave was increased. After the internal pressure of the autoclave has increased to 1.78 MPa (internal temperature is about 220 ° C.), pressure control is started (water in the system is released), the autoclave internal pressure is maintained at 1.78 MPa, and the reaction is continued for 2 hours. Then, the reaction was stopped (autoclave internal temperature: about 241 ° C.), cooled, and the prepolymer was taken out. The relative viscosity of the prepolymer obtained by drying in a vacuum oven at 80 ° C. for 12 hours was 1.38.
5.00 g of the obtained prepolymer was supplied to a glass tube having a diameter of 19 mm, and nitrogen substitution was repeated 5 times. Then, the pressure in the system was reduced to 300 Pa or less, and then 0.67 in a metal bath at 282 ° C. The post-polymerization reaction was performed for a time. The properties of the polymer are shown in Table 3.

Comparative Example 9 (Production of N46)
DN4 (293.47 g, 3.33 mol), AA (467.82 g, 3.20 mol) and deionized water (320 g) were added to a 3 L autoclave. After replacing with nitrogen three times, the internal pressure of the autoclave was maintained at 0.02 MPa. Subsequently, the set temperature of the autoclave was set to 214 ° C., the temperature increase was started, and the pressure of the autoclave was increased. After the internal pressure of the autoclave rises to 0.03 MPa (internal temperature is about 152 ° C.), pressure control is started (water in the system is released), the internal pressure of the autoclave is maintained at 0.03 MPa, When the amount of water outflow reached 250 g, the release of water from the autoclave was stopped. After continuing the reaction for 30 minutes, the reaction was stopped (pressure: about 1.14 MPa, temperature: about 214 ° C.). The polymer in the high-pressure autoclave was discharged and dried in a vacuum oven at 80 ° C. for 12 hours. The relative viscosity of the obtained prepolymer was 1.14.

5.00 g of the obtained prepolymer was supplied to a glass tube having a diameter of 19 mm, and after nitrogen substitution was repeated 5 times, the pressure in the system was reduced to 300 Pa or less, and then 3.0 ° C. in a metal bath at 260 ° C. After a time, the polymerization reaction was carried out. The properties of the polymer are shown in Table 3.
Example 9
The results are shown in Table 4 except that the diamine component is DN10, the postpolymerization reaction temperature is 240 ° C., and the postpolymerization time is 0.5 hours.

Comparative Example 10
The results are shown in Table 4 except that the diamine component and dicarboxylic acid component are DN10 and DBO, the postpolymerization reaction temperature is 240 ° C., and the postpolymerization reaction time is 3.0 hours.

Example 10
The results are shown in Table 4 in the same manner as in Example 1 except that the diamine component is DN5 / DN6.

Comparative Example 11
The results are shown in Table 4 except that the diamine component and dicarboxylic acid component are DN5 / DN6 and DBO, and the post-polymerization time is 5.0 hours.

Example 11
The results are shown in Table 5 except that DPO and DBO were used as the dicarboxylic acid component, and the post-polymerization time was 2.9 hours.

  When a polyamide resin is produced using diphenyl oxalate as the dicarboxylic acid component, the polymerization reaction time is shortened, the resulting polyamide resin has good melt residence stability, and the formamide end group content is relatively low.

  Polyamide resin obtained using dibutyl oxalate (with KI) as the dicarboxylic acid component improves the melt residence stability, but has a wide molecular weight distribution and low bending strength. Moreover, the polyamide resin obtained by using diphenyl oxalate exhibits much higher flexural modulus, flexural strength, and lower water absorption than general nylon.

  The polyamide resin of the present invention can be suitably used for various applications such as resin molded products such as automobile parts, electric / electronic parts, machine parts, household goods, office supplies, building materials, sports equipment, fibers, films, and the like.

Claims (13)

At least a polyamide resin obtained by polycondensation of a dicarboxylic acid component and a diamine component, wherein the dicarboxylic acid component contains diphenyl oxalate having a ratio of 20 to 100 mol% with respect to the total amount of the dicarboxylic acid component, However, the relative viscosity A at 25 ° C. of a 96% sulfuric acid solution containing 0.01 to 4 g of an aliphatic diamine having a carbon number of 4 to 12 and a ratio of 20 to 100 mol% with respect to the total amount of the diamine component is not less than 2.35. Polyamide resin of 0.00 or less. The ratio (B / A) of the relative viscosity B of the polyamide resin after melting and staying for 30 minutes in an inert gas atmosphere at a melting point + 20 ° C. and the relative viscosity A (B / A) is 0.80 to 2.0. The polyamide resin described. Using a differential scanning calorimeter, when the polyamide resin is cooled to 30 ° C. at a temperature decrease rate of 20 ° C./min from the molten state in an inert gas atmosphere, and then heated at a temperature increase rate of 20 ° C./min. The polyamide resin according to claim 1 or 2, wherein a temperature (Tm: melting point) of an endothermic peak that appears is 270 to 320 ° C. The polyamide resin according to any one of claims 1 to 3, wherein a ratio (E / F) of a supply molar amount E of the diamine component to a supply molar amount F of the dicarboxylic acid component is 0.90 to 1.10. The polyamide resin according to any one of claims 1 to 4, wherein the content of formamide end groups (-NH-CHO) is less than 0.12 mmol / g. The polyamide resin according to any one of claims 1 to 5, wherein the aliphatic diamine having 4 to 12 carbon atoms is 1,5-pentanediamine. The polyamide resin according to any one of claims 1 to 6, wherein the ratio (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polyamide resin measured by gel permeation chromatography test is 5.0 or less. . The polyamide resin according to any one of claims 1 to 7, further comprising one or more selected from transition metal halides, alkali metal halides, or alkaline earth metal halides in the polyamide resin. At least a method for producing a polyamide resin obtained by polycondensation of a dicarboxylic acid component and a diamine component, wherein the proportion of the dicarboxylic acid component relative to the total amount of the dicarboxylic acid component is 20 to 100 mol%, and the ratio relative to the total amount of the diamine component is The manufacturing method of the polyamide resin which mixes 20-100 mol% aliphatic C4-C12 aliphatic diamine, and superpose | polymerizes until the relative viscosity A becomes 2.35 or more and 6.00 or less. The method for producing a polyamide resin according to claim 9, comprising a step of post-polymerizing the prepolymer in a temperature range of 200 ° C to 335 ° C for less than 3 hours after synthesizing a prepolymer having a relative viscosity of 1.02 to 1.80. . The method for producing a polyamide resin according to claim 10, wherein the post-polymerization step time is less than 2 hours. 12. The polyamide resin according to claim 10, wherein at least one selected from transition metal halides, alkali metal halides, or alkaline earth metal halides is added during prepolymer synthesis or at the post-polymerization step. Manufacturing method. The method for producing a polyamide resin according to any one of claims 9 to 12, wherein a ratio (E / F) of a supply molar amount E of the diamine component to a supply molar amount F of the dicarboxylic acid component is 0.90 to 1.10.